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在炎热地区,将色彩艳丽的环境友好型高近红外反射颜料作为建筑外墙以及交通工具的外漆,可减少制冷所需要的空调能耗,可在满足人们视觉需求的同时,有效缓解城市"热岛效应".离子掺杂是调和颜料的色彩的重要手段.研究采用固相煅烧法制备了钆离子和钼离子共掺杂的(Gd_(0.5)Mo)_x(BiV)_(1-x)O_4 (x=0,0.1,0.2,0.3,0.4,0.5)近红外反射黄色颜料.通过X射线衍射仪(XRD)、紫外/可见/近红外分光光度计、色度仪和热重-示差扫描量热仪(TG-DSC)、扫描电子显微镜(SEM)等对颜料样品的结构组成、反射特性、颜色及热稳定性等进行了测试表征.结果表明,制备的颜料样品为单斜白钨矿结构,Gd~(3+)和Mo~(6+)通过取代Bi~(3+)和V~(5+),成功进入BiVO_4晶格.随着掺杂量的增加,样品颜色由暗黄向明黄转变,在700~2 500 nm波段近红外反太阳光射率最高达到82.5%.所制备的颜料具有良好的热稳定性.因而,黄色(Gd_(0.5)Mo)_x(BiV)_(1-x)O_4可作为热反射隔热候选颜料用于建筑及交通工具等领域.
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In hot areas,the use of colorful environment-friendly near-infrared (NIR) reflective pigments as the exterior paint of buildings and vehicles can reduce the energy consumption of air-conditioning required for refrigeration.It can not only meet the visual needs of people,but also effectively alleviate the urban island effect.Ion doping is an important means of blending pigments.A series of (Gd_(0.5)Mo)_x(BiV)_(1-x)O_4(x=0,0.1,0.2,0.3,0.4,0.5) pigments was synthesized via co-doping with Gd~(3+) and Mo~(6+) by solid-state calcination.The phase structure,color performance and morphology of developed powders were investigated by colorimetric spectrophotometer,X-ray diffraction (XRD),scanning electron microscopy (SEM),ultraviolet-visible-near infrared diffuse reflectance spectroscopy.The results showed that the synthesized pigment samples had a monoclinic scheelite structure with good crystallinity,and Gd~(3+) and Mo~(6+) were substitute for Bi~(3+) and V~(5+)successfully.With the increase of the doping amount,the color changes from dark yellow to bright yellow.Moreover,the synthesized pigments exhibited high NIR solar reflectance at a maximum of 82.5% in the range of 700-2 500 nm.The synthesized pigment samples had good thermal stability.The yellow (Gd_(0.5)Mo)_x(BiV)_(1-x)O_4 pigments can be used as a candidate material for heatreflecting and heat-insulating.
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首先,以TiCl_4为钛源,采用水热法制备空心板栗状TiO_2载体.然后,再以PbI_2及MAI(MA=CH_3NH_3 +)为前驱体,采用溶液法在空心板栗状TiO_2上一步构筑MAPbI_3薄膜,形成空心板栗状MAPbI_3/TiO_2复合光催化剂.以甲苯为目标降解物,考察板栗状MAPbI_3/TiO_2在可见光下的催化降解性能,并对材料的能级结构进行分析,揭示材料的降解机理.结果表明:钙钛矿型MAPbI_3薄膜的组成及形貌与PbI_2和MAI投料比密切相关,随着投料比的增加,薄膜的成分由MAPbI_3和MAI两相变为纯MAPbI_3,再转变MAPbI_3和PbI_2两相.能级匹配、结构特殊的板栗状MAPbI_3/TiO_2不仅可以降低光生电子和空穴的复合率,还能有效地将光生电子和空穴分别转移至MAPbI_3的导带及TiO_2价带,促进活性粒子·O_2~-和·OH的生成,因此在甲苯的降解中表现更优的性能.在可见光的照射下,MAPbI_3/TiO_2对甲苯的降解率在90 min内可高达98%.
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Firstly,hollow chestnut TiO_2 carrier was prepared by hydrothermal method with TiCl_4 as titanium source.Then,using PbI_2 and MAI as precursors,MAPbI_3 thin films were constructed on hollow chestnut TiO_2 by solution method to form hollow chestnut MAPbI_3/TiO_2 composite photocatalyst.Taking toluene as the target degradation material,the catalytic degradation performance of chestnut MAPbI_3/TiO_2 composite photocatalyst under visible light was investigated,and the energy level structure of the material was analyzed to reveal the degradation mechanism of the material.The results show that the composition and morphology of perovskite MAPbI_3 thin films are closely related to the feed ratio of PbI_2 and MAI.With the increase of feed ratio of PbI_2,the composition of the thin films changes from MAPbI_3 and MAI to pure MAPbI_3 and then to MAPbI_3 and PbI_2.The chestnut MAPbI_3/TiO_2 with matched energy level and special structure can not only reduce the recombination rate of photogenerated electrons and holes,but also effectively transfer the photogenerated electrons and holes to the conduction band of MAPbI_3 and TiO_2 valence band respectively,promoting the generation of active particles ·O_2~- and ·OH,so it has better performance in the degradation of toluene.Under the irradiation of visible light,the degradation rate of MAPbI_3/TiO_2 was up to 98% in 90 min.
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综合采用正相、反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱、半制备液相色谱等色谱方法进行化学成分分离纯化,运用核磁共振和质谱等波谱方法鉴定化合物的结构,对药用植物狗牙根[Cynodon dactylon(L.) Pers.]95%乙醇提取物进行化学成分研究,并对其中的黄酮类和蒽醌类进行抗炎活性研究.从狗牙根全草中分离得到16个化合物,分别鉴定为苜蓿素(1)、chrysoeriol (2)、isoliquiritigenin (3)、tricin 4 '-O-(threo-β-guaiacyl-(7''-O-methyl-9''-O-acetyl)-glyceryl) ether (4)、木犀草素(5)、tricin 4'-O-(erythro-β-guaiacylglyceryl) ether (6)、calquiquelignan D (7)、calquiquelignan E (8)、5,5'-dihydroxy-2',4'-dim-ethoxyflavone-7-O-β-D-(6''-O-Zp-coumaroyl)-glucopyranoside (9)、4'-hydroxy-2,3-dihydroflavone-7-β-D-glucopyranoside (10)、tricin 4'-O-(threo-β-guaiacyl-(7''-O-methyl)-glyceryl) ether (11)、ω-Hydroxyemodin (12)、phomarin (13)、aurantio-obtusin (14)、β-谷甾醇(15)、豆甾醇(16).除化合物5外,其他化合物均为首次从该植物中分离得到,其中化合物2、3和14显示显著抗炎活性,其IC_(50)值分别为2.74、2.35、3.61 μmol/L.
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The chemical constituents of the 95% ethanol extract from Cynodon dactylon (L.) Pers.were studied using silica gel,open ODS,Sephadex LH-20,and semi preparative HPLC column chromatography.The anti-inflammatory activities of isolated flavonoids and anthraquinones were studied.Sixteen compounds were isolated from bermudagrass and identified as tricin (1),chrysoeriol (2),isoliquiritigenin (3),tricin4 '-O-(threo-β-guaiacyl-(7''-O-methyl-9''-O-acetyl)-glyceryl) ether (4),luteolin (5),tricin 4'-O-(erythro-β-guaiacylglyceryl) ether(6),calquiquelignan D (7),calquiquelignan E (8),5,5 '-dihydroxy-2 ',4 '-dim-ethoxyflavone-7-O-β-D-(6 ' '-O-Z-pcoumaroyl)-glucopyranoside (9),4'-hydroxy-2,3-dihydroflavone-7-β-D-glucopyranoside (10),tricin 4'-O-(threo-β-guaiacyl-(7 ' '-O-methyl)-glyceryl) ether (11),ω-Hydroxyemodin (12),phomarin (13),aurantio-obtusin (14),β-sitosterol (15) and stigmasterol (16).Compounds 1,2,3,4,6,7,8,9,10,11,12,13,14,15 and 16 were isolated from this plant for the first time.Compounds 2,3 and 14 showed significant anti-inflammatory activity,with IC_(50) values of 2.74,2.35 μmol/L and 3.61 μmol/L.
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报道了一种有机催化合成2-吡啶酮衍生物的方法.以N-取代的3-羟基-2-吡啶酮和Morita-Baylis-Hillman(MBH)碳酸酯为原料,在亲核性有机胺催化下,经区域选择性O-烯丙基取代反应合成一系列含有2-吡啶酮片段的多官能团产物,产率51%~91%.在温和的反应条件下实现了3-羟基-2-吡啶酮类化合物的羟基功能化.
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A method of organocatalytic synthesis of 2-pyridone derivatives has been reported.Using Nsubstituted 3-hydroxy-2-pyridones and Morita-Baylis-Hillman (MBH) carbonates as raw materials,a series of multifunctional molecules featuring a 2-pyridone moiety were rapidly constructed in 51%-91% yields through nucleophilic amine-catalyzed regioselective O-allylic substitution reaction.Functionalization of OH group on Nsubstituted 3-hydroxy-2-pyridone compounds could be smoothly realized under the current reaction conditions.
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以溶剂热法合成了2例基于d~(10)金属离子的配合物[Zn(bmib)(HCOO)_2]·3H_2O(1)和[Cd(bmib)0.5(tdc)(DMF)(H_2O)](2)[bmib=1,4-双(2-甲基-1H-咪唑-1-基)苯,H_2tdc=2,5-噻吩二羧酸].2例配合物合成条件除金属盐不同外,其余均相同.结构分析揭示,配合物1中H_2tdc并未与金属中心配位,Zn~(2+)采取四配位的模式与2个HCOO~-和2个bmib配体连接形成一维"Z"字形链.配合物2中Cd~(2+)则采取六配位的模式,由bmib和H_2tdc配体共同桥连构成一维梯形链.结果表明金属中心对配合物的结构至关重要.热重分析显示2例配合物热稳定性较好.固体荧光性质表明配合物1和2有蓝色荧光特征,分别在460和470 nm处有最强荧光发射,有用作发光材料的潜在价值.
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Two d~(10) metal complexes [Zn(bmib)(HCOO)_2]·3H_2O (1) and [Cd(bmib)0.5(tdc)(DMF)(H_2O)] (2)(bmib=1,4-bis(2-bethyl-1H-imidazol-1-yl)benzene,H_2tdc=2,5-thiophenedicarboxylic acid) were synthesized by solvent thermal conditions.The synthesis conditions of the two complexes were the similar except for different metal salts.However,structural analysis revealed that H_2tdc in complex 1 did not participate in coordination.Structure of complex 1 was a 1D Z-shaped chain formed by bmib ligand and Zn~(2+).Complex 2 is a 1D ladder chain composed of bmib,H_2tdc and Cd~(2+).Results show that metal ions play an important role in the structure of complexes.Thermogravimetric analysis showed that the two complexes had good thermal stability.Solid fluorescence properties indicated that complexes 1 and 2 had blue fluorescence with the strongest fluorescence emission peak at 460 nm and 470 nm,respectively,which have potential value as luminescent materials.
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人参果(Solanum muricatum)是云南特色经济作物.长期施用化学肥料和农药,会导致人参果主产区土壤酸化、板结、有机质含量低和肥力退化等问题,同时作物病害严重、挂果率低等障碍因素突出.研究通过创制生物质有机肥改良人参果种植土壤,试验施用量分别为9、12、15 t/hm~2和18 t/hm~2,以传统单施尿素150 kg/hm~2为对照(CK),分析了土壤理化性质与酶活性,调查了不同处理下人参果枯叶病发病率和产量.结果表明:施用生物质有机肥显著提高了土壤pH、电导率(EC)、阳离子代换量(CEC)、有机质和速效氮、磷、钾含量(P<0.05),降低了土壤容重,增加了土壤磷酸酶、脲酶与多酚氧化酶活性(P<0.05),且活性随施用量增加而增加.与CK相比,施用生物质有机肥能显著改善土壤理化特征和增加土壤酶活性,从而提高人参果产量,且其解释率为87.40%.施加生物质有机肥降低了人参果枯叶病发病率(P<0.05),且其与产量的关联性符合对数曲线模型(R~2=0.794,P<0.01).与非种植障碍区相比,生物质有机肥以15~18 t/hm~2的施用量处理即可获得较高产量.因此,施用生物质有机肥部分替代化肥,可有效改良酸性红壤区土壤质量和缓减人参果病害,从而提高作物种植产量.
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Solanum muricatum,a unique cash crop in Yunnan Province,faces several significant challenges in its primary cultivation areas due to prolonged use of chemical fertilizers and pesticides.These challenges include soil acidification,compaction,low organic matter,declining fertility,severe crop diseases,and reduced yields.This study aimed to explore the impact of bio-organic fertilizer (BOF) on soil quality,enzyme activity,leaf blight incidence,and Solanum muricatum yields in a region with acidic and degraded soil conditions at a high plateau.Four different application rates of BOF (9,12,15,and 18 t/hm~2) were tested,with a control group using 150 kg/hm~2 of urea (CK).The findings indicated significant improvements (P<0.05) in various soil parameters,such as pH,electrical conductivity (EC),cation exchange capacity (CEC),organic matter content,and available nutrients,as well as increased activity of soil enzymes like phosphatase,urease,and polyphenol oxidase.Furthermore,a noticeable decrease (P<0.05) in soil bulk density was observed.Compared to the CK group,the application of BOF led to an enhanced Solanum muricatum yield by improving soil physicochemical properties and increasing soil enzyme activity,with an interpretation rate of 87.40%.Additionally,BOF application significantly reduced leaf blight in Solanum muricatum (P<0.05),and a significant logarithmic relationship was observed between Solanum muricatum yield (R~2= 0.794,P<0.01).Notably,in the presence of obstacles,the use of BOF at rates of 15 -18 t/hm~2 led to higher Solanum muricatum yields compared to non-obstacle planting areas.In conclusion,substituting chemical fertilizers with biomass organic fertilizer can substantially enhance soil physicochemical properties,reduce plant disease incidence,and increase Solanum muricatum yields.
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为了鉴定广西南宁种植基地的白及叶斑病病原菌种类并筛选出高效杀菌剂,采集了典型的叶斑病样品,对这些样品进行了病原菌的分离纯化,并根据科赫氏法则验证了分离株的致病性.结合形态特征和多基因序列联合分析,鉴定了病原菌的种类,并利用菌丝生长速率法评估了10种杀菌剂对代表菌株的抑制效果.结果显示本研究成功分离出了引起白及叶斑病的病原菌,即链格孢Alternaria alternata.将该病原菌接种到健康的白及叶片上可以引起与田间病害相似的症状.在对不同杀菌剂的测定中,肟菌戊唑醇对该菌菌丝生长的抑制效果最为显著,其EC_(50)值为1.25 μg/mL.
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In order to identify the pathogenic fungi causing Bletilla striata cultivation disease in the planting base of Nanning,Guangxi,and screen for highly effective fungicides,this study collected typical samples of leaf spot disease.The pathogenic fungi were isolated and purified,and the pathogenicity of the isolated strains was verified according to Koch's postulates.The identification of the pathogenic fungi species was performed through a combined analysis of morphological characteristics and multi-gene sequencing.The inhibitory effects of 10 fungicides on representative strains were determined using the mycelial growth rate method.The results showed that the isolated pathogenic fungi causing B.striata leaf spot disease were identified as Alternaria alternata,a species of chain spot fungus.Inoculating the pathogenic fungi onto healthy B.striata leaf samples resulted in disease symptoms similar to those observed in the field.Among the tested fungicides,oxathiapiprolin exhibited the strongest inhibition activity against the mycelial growth of this fungus,with an EC_(50) value of 1.25 μg/mL.The findings of this study provide scientific evidence for the identification and control of B.striata leaf spot disease.
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心肌梗死引起的大量心肌细胞损失导致心脏病理性重构和心力衰竭的发生,如何促进心肌再生是修复受损心脏的关键问题。心肌细胞再生主要源于原有心肌细胞的增殖已被广泛认同。近年来,该领域的快速发展加深了我们对心肌细胞再生的内源性细胞和微环境特征、外源性影响因素、分子生物学机制以及干预策略等各方面的认识。因此,我们对哺乳动物心肌细胞再生的定义、特征、评价和研究方法、调控机制以及干预措施等进行整理并形成共识,旨在明确该领域尚需进一步阐明的重要问题,推动心肌再生研究的深化及其在临床上的应用转化。
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Myocardial infarction (MI) leads to a massive loss of cardiomyocytes, resulting in pathological cardiac remodeling and heart failure. Promoting cardiomyocyte regeneration is crucial for repairing the damaged heart. It is acknowledged that regenerative cardiomyocyte derives from the existing cardiomyocytes. In recent years, advancements in this field have updated our understanding of cardiomyocyte regeneration in many aspects, including intrinsic cell source and microenvironmental characteristics, extrinsic factors, molecular biology mechanisms, and intervention strategies. Here, we report a consensus by an expert committee on the definition, characteristics, evaluation, research methods, regulatory mechanisms, and intervention measures related to mammalian cardiomyocyte regeneration. The aim is to clarify important unresolved issues in this field and to promote myocardial regeneration research and its clinical translation.
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本研究旨在探讨微管相关肿瘤抑制因子1 (microtubule associated tumor suppressor 1, MTUS1)对血红素诱导的血管内皮细胞凋亡的影响,并探讨其对血红素加氧酶1 (hemeoxygenase 1, HMOX1)表达的影响及具体机制。采用RNA测序、RT-qPCR和Western blot分析MTUS1敲低后人脐静脉内皮细胞(human umbilical vein endothelial cells, HUVEC)中血红素结合相关蛋白、 cAMP反应元件结合蛋白(cAMP response element-binding protein, CREB)和核呼吸因子2 (nuclear respiratory factor 2, NRF2)表达的变化,及MTUS1敲低对血红素诱导的HMOX1表达变化,CREB和NRF2过表达对MTUS1敲低介导的293T细胞中HMOX1表达变化的影响;CCK8及Western blot检测MTUS1或者HMOX1敲低对血红素诱导的HUVEC凋亡和存活的影响,NRF2过表达对MTUS1敲低介导的血红素诱导的293T细胞存活的影响。结果显示:小分子干扰RNA有效敲低HUVEC中MTUS1表达(P < 0.01),HUVEC中MTUS1敲低后,血红素结合相关蛋白中HMOX1下调显著(P < 0.01);MTUS1敲低能够抑制血红素诱导的HUVEC中HMOX1上调(P < 0.01),并能促进血红素诱导的HUVEC凋亡;HMOX1敲低能促进血红素诱导的HUVEC凋亡(P < 0.01);MTUS1敲低能抑制HUVEC中CREB和NRF2表达,NRF2过表达能部分逆转MTUS1敲低引起的293T细胞中HMOX1下调,并能部分逆转MTUS1敲低加剧的血红素诱导的293T细胞凋亡效应,但是CREB过表达不能。上述结果提示MTUS1部分通过NRF2上调HUVEC中HMOX1表达,从而抑制血红素诱导的血管内皮细胞凋亡。
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This study aimed to investigate the effects of microtubule associated tumor suppressor 1 (MTUS1) on hemeoxygenase 1 (HMOX1) expression and hemin-induced apoptosis of vascular endothelial cells and its regulatory mechanism. RNA sequencing, RT-qPCR and Western blot were used to assess altered genes of hemin binding proteins, the expression of cAMP response element-binding protein (CREB) and nuclear respiratory factor 2 (NRF2), hemin-induced HMOX1 expression in MTUS1 knockdown human umbilical vein endothelial cells (HUVEC), and the effect of overexpression of CREB and NRF2 on HMOX1 expression in MTUS1 knockdown 293T cells. The effect of MTUS1 or HMOX1 knockdown on hemin-induced apoptosis in HUVEC, and the overexpression of NRF2 on hemin-induced apoptosis in MTUS1 knockdown 293T cells were assayed with CCK8 and Western blot. The results showed that MTUS1 was knocked down significantly in HUVEC by siRNA (P < 0.01), accompanied by decreased HMOX1 expression (P < 0.01). The increased HMOX1 expression induced by hemin was also inhibited by MTUS1 knockdown (P < 0.01). And the apoptosis of HUVEC induced by hemin was amplified by MTUS1 or HMOX1 knockdown (P < 0.01). Moreover the expression of CREB and NRF2 were both inhibited by MTUS1 knockdown in HUVEC (P < 0.01). The decreased HMOX1 regulated by MTUS1 knockdown could be rescued partly by overexpression of NRF2 (P < 0.01), however, not by overexpression of CREB. And the MTUS1 knockdown mediated decreased 293T cells viability induced by hemin could be partly rescued by NRF2 overexpression (P < 0.01). These results suggest that MTUS1 can inhibit hemin-induced apoptosis of HUVEC, and the mechanism maybe related to MTUS1/NRF2/HMOX1 pathway.
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本文旨在研究6周高强度间歇训练(high-intensity interval training, HIIT)干预后小鼠肝脏酮体生成情况,并探讨可能的作用机制。将7周龄雄性C57BL/6J小鼠随机分为对照组和HIIT组,对照组不进行运动,而HIIT组接受为期6周HIIT (坡度为10°的跑台运动),记录体重和体成分的变化,在一次HIIT运动前、运动后即刻、运动后1 h检测血液酮体水平。6周HIIT后,用试剂盒检测肝脏和血清中游离脂肪酸的水平,用qPCR和Western blot检测小鼠肝脏酮体生成调节因子和关键酶表达情况。结果显示,与HIIT前相比,一次HIIT后即刻、HIIT后1 h HIIT组小鼠血酮体水平显著上升。对照组小鼠的体重在6周内逐渐增加,HIIT组小鼠体重没有显著增加。6周HIIT结束之后,与对照组相比,HIIT组体脂比显著降低,而瘦体重占比显著增加,肝脏和血清游离脂肪酸水平显著升高,肝脏肉碱棕榈酰转移酶-I (carnitine palmitoyl transferase-I, CPT-I)、过氧化物酶体增殖物激活受体α (peroxisome proliferator-activated receptor α, PPARα)和成纤维细胞生长因子21 (fibroblast growth factor 21, FGF21)蛋白表达水平显著上调,哺乳动物雷帕霉素靶蛋白复合体1 (mammalian target of rapamycin complex 1, mTORC1)蛋白表达显著下调。以上结果提示,HIIT可能通过改变mTORC1、PPARα和FGF21表达来诱导小鼠肝酮体的生成。
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The present study aims to investigate the production of ketone body in the liver of mice after 6 weeks of high-intensity interval training (HIIT) intervention and explore the possible mechanisms. Male C57BL/6J mice (7-week-old) were randomly divided into control and HIIT groups. The control group did not engage in exercise, while the HIIT group underwent a 6-week HIIT (10° slope treadmill exercise). Changes in weight and body composition were recorded, and blood ketone body levels were measured before, immediately after, and 1 h after each HIIT exercise. After 6-week HIIT, the levels of free fatty acids in the liver and serum were detected using reagent kits, and expression levels of regulatory factors and key enzymes of ketone body production in the mouse liver were detected by Western blot and qPCR. The results showed that, the blood ketone body levels in the HIIT group significantly increased immediately after a single HIIT and 1 h after HIIT, compared with that before HIIT. The body weight of the control group gradually increased within 6 weeks, while the HIIT group mice did not show significant weight gain. After 6-week HIIT, compared with the control group, the HIIT group showed decreased body fat ratio, increased lean body weight ratio, and increased free fatty acid levels in liver and serum. Liver carnitine palmitoyl transferase-I (CPT-I), peroxisome proliferator activated receptor α (PPARα), and fibroblast growth factor 21 (FGF21) protein expression levels were up-regulated, whereas mammalian target of rapamycin complex 1 (mTORC1) protein expression level was significantly down-regulated in the HIIT group, compared with those in the control group. These results suggest that HIIT induces hepatic ketone body production through altering mTORC1, PPARα and FGF21 expression in mice.
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本文旨在探讨骨髓间充质干细胞来源的外泌体(exosomes derived from bone marrow mesenchymal stem cells, BMSCs- EXO)对大鼠肺缺血再灌注损伤(ischemia-reperfusion injury, IRI)的影响及miR-335在其中的作用及机制。通过左肺夹闭60 min、开放180 min建立大鼠肺IRI模型。Sprague-Dawley大鼠40只随机分为假手术组(sham)、IRI组、IRI+PBS组、IRI+EXO组和IRI+inhibitor-EXO组(n = 8)。Sham组大鼠仅开胸,但不建立肺IRI模型;IRI组建立肺IRI模型,无其他任何处理;其它3组建立肺IRI模型后,于再灌注前分别给予PBS、无任何处理的BMSCs-EXO和经miR-335抑制剂处理的BMSCs-EXO。实验中进行血气分析;再灌注结束后检测肺组织湿/干重比(wet/dry ratio, W/D),以及白介素1β (interleukin-1β, IL-1β)、肿瘤坏死因子α (tumor necrosis factor-α, TNF-α)、髓过氧化物酶(myeloperoxidase, MPO)、丙二醛(malondialdehyde, MDA)、超氧化物歧化酶(superoxide dismutase, SOD)含量;电镜下观察线粒体并记录Flameng评分;光镜下观察肺组织病理学,记录肺损伤评分(lung injury score, LIS);TUNEL法检测细胞凋亡情况,并计算细胞凋亡指数(apoptosis index, AI);RT-qPCR检测miR-335表达, Western blot检测caspase-3、cleaved-caspase-3、caspase-9、cleaved-caspase-9、NF-κB蛋白表达。结果显示,再灌注后,与sham组相比,IRI组和IRI+PBS组氧合指数、pH、碱剩余(base excess, BE)显著降低,而与IRI+PBS组相比,IRI+EXO组氧合指数、pH、BE显著升高,与IRI+EXO组相比,IRI+inhibitor-EXO组氧合指数、pH、BE显著降低(P < 0.05)。与sham组相比, IRI组W/D、IL-1β、TNF-α、MPO、MDA、LIS、AI、Flameng评分及caspase-3、cleaved-caspase-3、caspase-9、cleavedcaspase- 9蛋白表达显著升高,NF-κB蛋白表达降低,SOD和miR-335表达显著降低(P < 0.05),但IRI组和IRI+PBS组相比无显著差异。与IRI+PBS组相比,IRI+EXO组W/D、IL-1β、TNF-α、MPO、MDA、LIS、AI、Flameng评分以及caspase-3、 cleaved-caspase-3、caspase-9、cleaved-caspase-9蛋白表达显著降低,NF-κB蛋白表达升高,SOD和miR-335表达显著升高(P < 0.05)。与IRI+EXO组相比,IRI+inhibitor-EXO组中上述指标的变化均反转,但仍优于IRI+PBS组(P < 0.05)。上述结果表明, BMSCs-EXO能够上调miR-335,维持线粒体结构稳定,激活NF-κB通路并减轻大鼠肺IRI。
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This study aimed to investigate the effect of exosomes derived from bone marrow mesenchymal stem cells (BMSCs-EXO) on lung ischemia-reperfusion injury (IRI) in rats and to explore the role of miR-335. The model of rat lung IRI was established by clipping the hilum of left lung for 60 min and opening for 180 min. Forty Sprague-Dawley rats were randomly divided into sham group, IRI group, IRI+PBS group, IRI+EXO group, and IRI+miR-335 inhibitor EXO (IRI+inhibitor-EXO) group (n = 8). Rats in the sham group underwent thoracotomies without IRI. Rats in the IRI group were used to establish IRI model without any additional treatment. In the IRI+PBS, IRI+EXO, and IRI+inhibitor-EXO groups, the rats were used to establish IRI model and given PBS, EXO from BMSCs without any treatment, and EXO from BMSCs with miR-335 inhibitor treatment before reperfusion, respectively. Blood gases were analyzed during the experiment. Lung tissue wet/dry ratio (W/D), interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), myeloperoxidase (MPO), malondialdehyde (MDA), and superoxide dismutase (SOD) were measured at the end of reperfusion. Mitochondria were observed by electron microscopy and the Flameng scores were counted. Lung histopathology and apoptosis (TUNEL staining) were observed by light microscopy, and the lung injury scores (LIS) and apoptosis index (AI) were detected. The miR-335 expression was detected by RT-qPCR, and the expression of caspase-3, cleaved-caspase-3, caspase-9, cleaved-caspase-9, and NF-κB proteins were detected by Western blot at the end of reperfusion. The results showed that compared with the sham group, the oxygenation index, pH, and base excess (BE) were significantly lower in the IRI group and IRI+PBS group after reperfusion, whereas those indices were significantly higher in the IRI+EXO group than those in the IRI+PBS group (P < 0.05). Compared with the sham group, there were significant increases in W/D, IL-1β, TNF-α, MPO, MDA, LIS, AI, Flameng score, caspase-3, cleaved-caspase-3, caspase-9, and cleaved-caspase-9, however significant decreases in the SOD, miR-335 and NF-κB in the IRI group (P < 0.05). These indices in the IRI and IRI+PBS groups showed no significant differences. Compared with the IRI+PBS group, there were significant decreases in W/D, IL-1β, TNF-α, MPO, MDA, LIS, AI, Flameng score, caspase-3, cleaved-caspase-3, caspase-9, and cleaved-caspase-9, however significant increases in the SOD, miR-335 and NF-κB in the IRI+EXO group (P < 0.05). While, the changes of the above mentioned indices were reversed in the IRI+inhibitor-EXO group compared with IRI+EXO group, which were still better than those in the IRI+PBS group (P < 0.05). The results suggest that BMSCs-EXO could attenuate lung IRI in rats, activate NF-κB pathway, and maintain mitochondrial stability by up-regulating miR-335.
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本研究旨在观察阿尔茨海默病(Alzheimer's disease, AD)动物模型海马组织中热休克蛋白90 (heat shock protein 90, HSP90)、β-淀粉样蛋白(amyloid-β, Aβ)以及Tau磷酸化水平在不同月龄的变化规律。将6、9、12月龄的APP/PS1转基因小鼠分为3个实验组,同月龄的C57BL/6J小鼠为相应对照组,每组8只。用Morris水迷宫检测各组小鼠的认知行为学能力;Western blot或免疫组织化学检测小鼠海马组织中HSP90、Aβ_(1-42)的表达以及Tau蛋白磷酸化水平;qRT-PCR检测海马组织hsp90 mRNA的表达;尼氏染色检测小鼠海马神经细胞形态和数量的变化。结果显示,APP/PS1转基因小鼠相较于同月龄的C57BL/6J小鼠,其海马组织中HSP90和hsp90 mRNA的表达降低(P < 0.05或P < 0.01),Aβ_(1-42)和Tau蛋白磷酸化水平则升高(P < 0.05或P < 0.01);不同月龄的APP/PS1转基因小鼠之间比较后发现,其海马组织中HSP90和hsp90 mRNA表达降低(P < 0.05或P < 0.01)以及Aβ_(1-42)和Tau蛋白磷酸化水平升高(P < 0.01或P < 0.05)均随着月龄的增加呈现进行性发展,同时其认知能力也逐渐减退。以上结果提示,APP/PS1小鼠海马组织中HSP90表达降低、Aβ_(1-42)和Tau蛋白磷酸化水平升高及其认知功能降低均呈现年龄依赖性。
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The present study aims to observe the change in expression of heat shock protein 90 (HSP90) along with amyloid-β (Aβ) and phosphorylated Tau (p-Tau) protein levels in the hippocampus tissue of Alzheimer's disease (AD) transgenic animal model with age. APP/PS1 transgenic mice at age of 6-, 9- and 12-month and C57BL/6J mice of the same age were used. The cognitive abilities of these animals were evaluated using a Morris water maze. Western blot or immunohistochemistry was used to detect the expressions of HSP90 and Aβ_(1-42), as well as the phosphorylation levels of Tau protein in the hippocampus. The hsp90 mRNA levels and the morphology and number of cells in the hippocampus were detected with real-time quantitative polymerase chain reaction (qRT-PCR) and Nissl staining, respectively. The results showed that compared with C57BL/6J mice of the same age, HSP90 and hsp90 mRNA expression were decreased (P < 0.05 or P < 0.01), while Aβ_(1-42) and p-Tau protein levels were increased (P < 0.05 or P <0.01) in the hippocampal tissue of APP/PS1 transgenic mice. Meanwhile, the decrease in HSP90 and hsp90 mRNA expression (P < 0.05 or P < 0.01), the increase in Aβ_(1-42) and p-Tau levels (P < 0.01 or P < 0.05) in hippocampal tissue and the reduction in behavioral ability showed a progressive development with the advancing of age in the APP/PS1 transgenic mice. In conclusion, in the hippocampal tissue of APP/PS1 mice, the decrease in HSP90 expression and the increase in Aβ_(1-42) and p-Tau levels together with the decline of their cognitive ability are age-dependent.
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脓毒症相关性脑病(sepsis-associated encephalopathy, SAE)是指由脓毒症引起的弥漫性脑功能障碍,其临床主要特征为注意力下降,定向力障碍,易激惹,严重时患者会出现昏睡、昏迷等症状。SAE的发病机制主要包括神经炎症、血脑屏障破坏、脑血管功能障碍以及神经代谢改变,其中神经炎症是SAE的核心病理过程。小胶质细胞被视为中枢神经系统的重要免疫细胞,在神经炎症中具有重要作用。本文系统描述了小胶质细胞在SAE发生和发展中扮演的角色,并详细探讨了小胶质细胞的表型和相关信号通路,以期明确小胶质细胞在SAE中的作用,为临床治疗提供理论基础。
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Sepsis-associated encephalopathy (SAE) refers to diffuse brain dysfunction caused by sepsis, which is characterized by decreased attention, directional impairment, being prone to irritation, and in severe cases the patient will experience drowsiness and coma. The pathogenesis of SAE mainly includes neuroinflammation, damage of blood-brain barrier, cerebral vascular dysfunction, and neurometabolic changes, among which neuroinflammation is the core pathological process. Microglia are considered to be important immune cells of the central nervous system and play an important role in neuroinflammation. This article systematically describes the role of microglia in the development of SAE, and discusses the phenotype and related signaling pathways of microglia, in order to clarify the role of microglia in SAE and provide a theoretical basis for clinical treatment of SAE.
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延迟性肌肉酸痛(delayed-onset muscle soreness, DOMS)是机体经历运动强度突然增加或不熟悉的运动后,在一段时间内所出现的肌肉酸痛现象。DOMS可影响运动员和健身人群的运动功能,降低竞技体育运动的成绩和体育锻炼成效。 DOMS的典型症状是触压痛,可同时存在痛觉过敏,具体机制尚不完全明确。近年来诸多研究证实,神经生长因子(nerve growth factor, NGF)和胶质细胞源性神经营养因子(glial cell derived neurotrophic factor, GDNF)等神经营养因子参与DOMS的发生和维持。本文对NGF与GDNF参与DOMS的相关信号通路研究进展作一综述,以期厘清DOMS中触压痛和痛觉过敏的产生机制,并为相关治疗提供新的思路。
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Delayed-onset muscle soreness (DOMS) is a common phenomenon that occurs following a sudden increase in exercise intensity or unfamiliar exercise, significantly affecting athletic performance and efficacy in athletes and fitness individuals. DOMS is characterized by allodynia and hyperalgesia, and their mechanisms remain unclear. Recent studies have reported that neurotrophic factors, such as nerve growth factor (NGF) and glial cell derived neurotrophic factor (GDNF), are involved in the development and maintenance of DOMS. This article provides a review of the research progress on the signaling pathways related to the involvement of NGF and GDNF in DOMS, hoping to provide novel insights into the mechanisms underlying allodynia and hyperalgesia in DOMS, as well as potential targeted treatment.
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本能行为主要受遗传控制,但也受到社交隔离等社交经历的调控。在果蝇和小鼠等模式动物的研究中已经发现社交隔离可以引起激素、神经递质、神经肽等分子水平以及神经环路层面的变化,进而调控动物的本能行为。本文主要对社交隔离通过改变物种保守的神经肽和神经递质的表达进而调控动物睡眠、生殖行为、攻击行为等本能行为的最新进展进行综述,以期深化理解社交隔离调控本能行为的关键且保守的信号通路。
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Innate behavior is mainly controlled by genetics, but is also regulated by social experiences such as social isolation. Studies in animal models such as Drosophila and mice have found that social isolation can regulate innate behaviors through the changes at the molecular level, such as hormone, neurotransmitter, neuropeptide level, and at the level of neural circuits. In this review, we summarized the research progress on the regulation of social isolation on various animal innate behaviors, such as sleep, reproduction and aggression by altering the expression of conserved neuropeptides and neurotransmitters, hoping to deepen the understanding of the key and conserved signal pathways that regulate innate behavior by social isolation.
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肝癌是一种常见的消化系统肿瘤,肝细胞癌(hepatocellular carcinoma, HCC)作为一种较为常见的肝癌类型,其恶性程度高且在全球癌症相关死亡原因中排在前列。代谢重编程被认为是癌症发生和发展的一个重要标志,糖代谢是细胞产生能量的主要途径之一。糖酵解作为糖代谢的基础性反应在细胞的代谢中发挥着举足轻重的作用,因此糖酵解的调控对于肿瘤的增殖与演变有着重要意义。越来越多的非编码RNA (non-coding RNA, ncRNA)被证实在肿瘤的糖酵解调控中发挥重要作用。本文综述了ncRNA在HCC糖酵解调控中的作用及相关机制,同时对基于糖酵解调控相关机制的靶向治疗HCC的方法提出展望。
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Liver cancer is a common tumor of digestive system. Hepatocellular carcinoma (HCC) is a common type of liver cancer, which has a high degree of malignancy and ranks among the top causes of cancer-related death in the world. Metabolic reprogramming is considered to be an important marker of carcinogenesis. Glucose metabolism is one of the main ways for cells to produce energy. Glycolysis, as the basic reaction of glucose metabolism, plays an important role in cell metabolism. Therefore, the regulation of glycolysis is of great significance to the proliferation and evolution of tumors. More and more non-coding RNAs (ncRNA) have been proved to play an important role in the regulation of tumor glycolysis. This article reviews the role of ncRNA in the regulation of HCC glycolysis and its related mechanisms. At the same time, the prospect of targeted therapy for HCC based on the related mechanisms of glycolysis regulation is put forward.
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肌动蛋白成核因子主要分为3类:Arp2/3复合体、Spire和Formin蛋白。其中Spire通过稳定的纵向四聚体成核组装微丝,将肌动蛋白结合到微丝生长端。早在1999年Wellington等人就发现Spire是肌动蛋白的成核剂,然而多年来的研究大多数着眼于Arp2/3、Formin蛋白,作为肌动蛋白成核因子的一员,关于Spire的相关研究相对较少。有研究显示,Spire蛋白通过合成肌动蛋白参与到囊泡运输过程。近几年还有研究发现,Spire在神经发育方面也有着重要作用。本文希望通过对Spire的结构、表达、功能以及与疾病的关联等方面的研究进行梳理,以便找到未来针对Spire研究富有意义的可能方向。
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There are three main classes of actin nucleation factors: Arp2/3 complexes, Spire and Formin. Spire assembles microfilaments by nucleating stable longitudinal tetramers and binding actin to the growing end of the microfilament. As early as 1999, Wellington et al. identified Spire as an actin nucleating agent, however, over the years, most studies have focused on Arp2/3 and Formin proteins; there has been relatively less research on Spire as a member of the actin nucleating factors. Recent studies have shown that Spire is involved in the vesicular transport through the synthesis of actin and plays an important role in neural development. In this paper, we reviewed the structure, expression and function of Spire, and its association with disease in order to identify meaningful potential directions for studies on Spire.
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程序性死亡配体1 (programmed death-ligand 1, PD-L1)在维持正常组织中枢和外周免疫耐受、介导肿瘤免疫逃逸以及维持抗炎和促炎反应平衡方面具有重要意义。炎症反应在肺部炎症性疾病中发挥了重要作用。本文综述了PD-L1在急性肺损伤、慢性阻塞性肺疾病、哮喘、特发性肺纤维化等肺部炎症性疾病中的研究进展和潜在的临床价值。
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Programmed death-ligand 1 (PD-L1) is important in maintaining central and peripheral immune tolerance in normal tissues, mediating tumor immune escape and keeping the balance between anti- and pro-inflammatory responses. Inflammation plays an important role in inflammatory lung diseases. This article reviews the research progress and potential clinical value of PD-L1 in inflammatory lung diseases, including acute lung injury, chronic obstructive pulmonary disease, asthma and idiopathic pulmonary fibrosis.
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目前针对RSA-CRT的建模类攻击研究较少,本文以模约减操作为研究对象,提出了一种针对RSA-CRT实现的模板攻击方法.该方法的核心是解决了如何由模约减后中间值的汉明重量恢复RSA-CRT私钥的难题.该方法的特点是基于模约减后中间值的汉明重量模型建模,通过采集选择密文模约减的能量迹进行模板匹配获取模约减后中间值的汉明重量,由汉明重量变化值恢复中间值,进一步恢复RSA-CRT算法的私钥.另外,该方法的优点在于理想情况下,基于中间值汉明重量模型建立的模板之间可以共用,且对中间值以多少位大小建模没有限制,可以选择字节大小,64位大小,甚至私钥p相同大小,实际环境中可根据泄露信息情况进行选取.最后,本文选择对中间值的最低字节进行建模,验证了该方法的可行性,并给出了防护建议.
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At present, there are few researches on profile attacks against RSA-CRT implementation. This paper takes modular reduction operation as the research object, and a template attack method against RSA-CRT implementation is proposed. The core of this method is to solve the difficulty to recover the RSA-CRT private key from the Hamming weight of the intermediate value of ciphertext modular reduction. The characteristic of this method is to build a model based on the Hamming weight of the intermediate value derived from modular reduction. The Hamming weight can be obtained by collecting the power traces of chosen ciphertext modular reduction for template matching, and the intermediate value is recovered from the Hamming weight variation, the private key of the RSA-CRT algorithm can be further inferred based on the intermediate value. In addition, the advantage of this method is that ideally, templates based on the intermediate Hamming weight model can be shared, and there is no limit on the number of bits of the intermediate value for modelling, which can be in byte size, 64 bit size, or even the bit size of p. In the actual environment, it can be selected according to the leaked information. Finally, in this paper, the lowest byte of the intermediate value is selected to model to verify the feasibility of this method, and the defense suggestions are also provided.
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在自动驾驶感知系统中视觉传感器与激光雷达是关键的信息来源,但在目前的3D目标检测任务中大部分纯点云的网络检测能力都优于图像和激光点云融合的网络,现有的研究将其原因总结为图像与雷达信息的视角错位以及异构特征难以匹配,单阶段融合算法难以充分融合二者的特征.为此,本文提出一种新的多层多模态融合的3D目标检测方法:首先,前融合阶段通过在2D检测框形成的锥视区内对点云进行局部顺序的色彩信息(Red Green Blue, RGB)涂抹编码;然后将编码后点云输入融合了自注意力机制上下文感知的通道扩充PointPillars检测网络;后融合阶段将2D候选框与3D候选框在非极大抑制之前编码为两组稀疏张量,利用相机激光雷达对象候选融合网络得出最终的3D目标检测结果.在KITTI数据集上进行的实验表明,本融合检测方法相较于纯点云网络的基线上有了显著的性能提升,平均mAP提高了6.24%.
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Camera and lidar are the key sources of information in autonomous vehicles (AVs). However, in the current 3D object detection tasks, most of the pure point cloud network detection capabilities are better than those of image and laser point cloud fusion networks. Existing studies summarize the reasons for this as the misalignment of view between image and radar information and the difficulty of matching heterogeneous features. Single-stage fusion algorithm is difficult to fully fuse the features of both. For this reason, a nova 3D object detection based on multilayer multimodal fusion (3DMMF) is presented. First, in the early-fusion phase, point clouds are encoded locally by Frustum-RGB-PointPainting (FRP) formed by the 2D detection frame. Then, the encoded point cloud input is combined with the self-attention mechanism contextaware channel to expand the PointPillars detection network. In the later-fusion phase, 2D and 3D candidate boxes are coded as two sets of sparse tensors before they are not greatly suppressed, and the final 3D target detection result is obtained by using the camera lidar object candidates fusion (CLOCs) network. Experiments on KITTI datasets show that this fusion detection method has a significant performance improvement over the baseline of pure point cloud networks, with an average mAP improvement of 6.24%.
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动态密码的设计与分析是当前密码学领域研究的热点.本文针对类CLEFIA动态密码结构和四分组CLEFIA变换簇抵抗不可能差分和零相关线性分析的能力进行评估.当两类动态密码结构的轮函数为双射时,通过研究密码组件的可交换性质,证明了这两类动态密码结构各自置换等价于标准静态密码结构.利用建立的置换等价关系,通过构造静态密码结构不可能差分和零相关线性区分器,证明了4n轮类CLEFIA动态密码结构所有结构均存在8轮的不可能差分和零相关线性区分器,证明了4n轮四分组CLEFIA变换簇所有结构均存在9轮的不可能差分和零相关线性区分器.
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The design and analysis of dynamic block ciphers are the frontier of current cryptography research. For CLEFIA-like dynamic cryptographic structure and four-block CLEFIA-like transform cluster, this paper focuses on the security evaluation against impossible differential cryptanalysis and zero correlation linear cryptanalysis. When the round functions of the two dynamic cryptographic structures are bijective, by studying the commutative properties of the modules, the fact that the two dynamic cryptographic structures are permutation equivalence of the two static structures respectively can be proved. With the established equivalence relation, by constructing the impossible differential and zero correlation distinguishers of two static structures, 8-round impossible differentials and zero correlation linear hulls of 4n-round CLEFIAlike dynamic cryptographic structure can be found as well 9-round ones for 4n-round four-block CLEFIA-like transform cluster.
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基于同步地球轨道(Geostationary Earth Orbit, GEO)卫星的机会源技术已被证明其在近岸海面高度测量中的应用潜力,但目前研究主要围绕可行性论证展开,极少开展全方位的测量性能评估.为此,从仿真和试验两个角度评估了信号带宽、非相干累加次数、信噪比及波形峰值跟踪算法对GEO卫星机会源海面测高性能的影响.评估结果表明当非相干累加次数和信噪比大于最优非相干累加次数和最优信噪比时,测高性能将不再显著提升.因此,通过选择最优非相干累加次数,以及设计合理的接收天线增益、射频增益及接收机带宽使信噪比大于最优信噪比对GEO卫星机会源海面测高至关重要.通过对比插值和拟合两种波形跟踪算法发现拟合法能提供比插值法更高的测量精度.利用北斗B3I信号和ASTRA 19.2 E卫星信号开展GEO卫星海面测高的试验评估.试验结果表明:在非相干累加次数大于10 000、信噪比大于7 dB时,北斗B3I信号和ASTRA 19.2 E卫星信号可分别提供精度约为0.20 m和0.10 m的海面高度.针对GEO卫星多频或多通道传输特点,提出了基于信号频谱合成提高海面测高精度的方法.当利用中卫1号卫星10个通道信号进行合成时,插值法和拟合法的仿真测距精度分别为3.50 cm和0.69 cm.
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It is potential to measure sea surface height using opportunity of source from geostationary earth orbit (GEO) satellites. Most studies focus on the experimental demonstrations, but few works comprehensively assess its performance. Based on this, the paper evaluates the influence of the signal bandwidth, incoherent integration number, signal-tonoise ratio (SNR) and retracking algorithm on the oceanic altimetry performance. It is found that once the incoherent integration number and SNR are over the optimal incoherent integration number and SNR, the improvements of the altimetry performances are insignificant. Therefore, choosing optical incoherent average number, and designing the receiver antenna gain, radio-frequency gain, and receiver bandwidth to obtain optical SNR are needed. The fitting method can provide a better precision than the interpolation method. The data from the BeiDou B3I signal and ASTRA 19.2 E satellite experiments are used to assess the GEO opportunity-source altimetry. The experiment results show that for the incoherent average number and SNR over 10 000 and 7 dB, respectively, the altimetry precision of about 0.20 m and 0.10 m can be obtained, respectively. Due to multi-frequency or multi-channel transmission, the spectral synthesis is proposed to improve the altimetry precision. The simulation results show that the synthetized signal from 10-channel signals of Zhongwei-1 satellite provides a precision of 3.50 cm and 0.69 cm for the interpolation and fitting method.
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星基增强系统(Satellite Based Augmentation System, SBAS)的电文格式公开,为防止SBAS服务遭受生成式欺骗攻击,国际民航组织积极推进SBAS认证服务标准的制定.本文面向北斗星基增强系统(BeiDou Satellite-Based Augmentation System, BDSBAS)阐述了基于中国商用密码算法的椭圆曲线数字签名(Elliptic Curve Digital Signature Algorithm, ECDSA)电文认证方案与时间效应流丢失容错(Time Efficient Stream Loss-tolerant Authentication, TESLA)电文认证方案,设计了BDSBAS认证电文,依据空中密钥管理OTAR(Over The Air Rekeying)的策略制定了OTAR电文(OTAR Message Type, OMT)与播发方案.通过蒙特卡洛OTAR仿真器开展仿真,对不同OTAR电文接收时间进行分析,本文设计的方案与国外方案对比结果有明显的提升,有效的减少了接收机完成认证使用SBAS增强服务的时间,对BDSBAS电文认证服务提供一定参考与建议.
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The message format of the satellite based augmentation system (SBAS) is open, and the system is relatively fragile. In order to prevent the SBAS service from being subjected to generative spoofing attacks, the international civil aviation organization (ICAO) actively promotes the formulation of the SBAS certification service standard. This paper expounds the elliptic curve digital signature Algorithum (ECDSA) message authentication scheme and the time efficient stream loss-tolerant authentication (TESLA) message authentication scheme based on the Chinese commercial cryptographic algorithm for the Beidou satellite based augmentation system (BDSBAS). The BDSBAS authentication message is designed, and according to the air key management OTAR(Over The Air Rekeying) strategy formulates the OTAR message type (OMT) and broadcast scheme. The Monte Carlo OTAR simulator is used to simulate and analyze the receiving time of different OTAR messages. The results of the scheme designed in this paper are significantly improved compared with foreign schemes, which effectively reduces the time for the receiver to complete the authentication with the SBAS enhanced service. The message authentication service provides certain references and suggestions.
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聚类是一种典型且重要的数据挖掘方法,但现有聚类算法大多需要人为指定聚类的数量,并且聚类结果对参数敏感.针对上述不足,本文提出一种基于子博弈完美均衡的启发式聚类算法(Heuristic Clustering algorithm based on Sub-game Perfect Equilibrium,HCSPE).该算法充分挖掘数据点自身的分布特征信息,通过启发式方法得到自适应的参数值,从而使数据点局部密度属性值的得出具有客观性和普适性,降低了聚类结果对参数的敏感性.基于博弈的思想,综合局部密度和相对距离两个属性形成数据点的竞争力,依靠竞争机制完成聚类数量的自动计算以及聚类中心的确定.在多个规模和类型均不相同的数据集上的实验结果表明,本文所提出算法的性能指标整体优于其他算法,并且聚类结果更符合客观所需.
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Clustering is a typical and important data mining method, but most of the existing clustering algorithms need to specify the number of clusters artificially, and the clustering results are sensitive to parameters. To address the above shortcomings, this paper proposes a heuristic clustering algorithm based on sub-game perfect equilibrium (HCSPE). The algorithm fully exploits the information of the distribution characteristics of data points themselves and obtains the adaptive parameter values by heuristic methods, so that the local density attribute values of data points are derived with objectivity and universality, and the sensitivity of clustering results to parameters is reduced. Based on the idea of game, the two attributes of local density and relative distance are integrated to form the competitiveness of data points, and the automatic calculation of the number of clusters and the determination of cluster centers are completed by relying on the competition mechanism. The experimental results on several data sets of different sizes and types show that the performance indexes of the proposed algorithm are better than other algorithms in general, and the clustering results are more in line with the objective requirements.
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集成方法是不平衡学习方法的重要分支,然而,现有不平衡集成方法均作用于原样本而没考虑样本的结构信息,因此其效能仍然有限.样本的结构信息包括局部和全局结构信息.为了解决上述问题,本文提出了一种基于深度样本包络网络(Deep Instance Envelope Network, DIEN)和分级结构一致性机制(Hierarchical Structure Consistency Mechanism, HSCM)的不平衡集成学习算法.该算法在考虑局部流形和全局结构信息的情况下,通过多层样本聚类,生成高质量的多层包络样本,从而实现类平衡化.首先,算法基于样本近邻拼接和模糊C均值聚类算法,设计DIEN来挖掘样本的结构信息,得到深度包络样本.然后,设计局部流形结构度量和全局结构分布度量来构建HSCM用于增强层间样本的分布一致性.接着,将DIEN和HSCM结合起来,构建出优化后的深度样本包络网络——DH(DIEN with HSCM).之后,将基分类器应用于包络样本.最后,设计bagging集成学习机制来融合基分类器的预测结果.文末组织了多组实验,采用了十多个公共数据集和有代表性的相关算法进行验证比较.实验结果表明,本文算法在AUC(Area Under Curve), F-measure等四个性能指标上显著最优.
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Ensemble methods have become an important branch of imbalanced learning. However, the existing imbalanced ensemble methods all rely on the original instances without considering the structure information of the instances, so their effectiveness is still limited. The research shows that the structure information of instances includes local and global structure information. In order to solve the above problem, this paper proposes an imbalanced ensemble algorithm based on deep instance envelope network (DIEN) and hierarchical structure consistency mechanism (HSCM). Considering the local manifold and global structure information, the algorithm generates high-quality deep envelope instances to achieve class balance. Firstly, based on the instance neighborhood concatenation and fuzzy c-means clustering algorithm, the DIEN is designed to mine the structure information of instances, obtaining the deep envelope instances. Then, the local manifold structure measure and global structure distribution measure are designed to construct the HSCM to enhance the distribution consistency of interlayer instances. Next, DIEN and HSCM are combined to construct the optimized deep instance envelope network—DH (DIEN with HSCM). Then, the base classifier is applied to the deep envelope instances. Finally, the bagging ensemble learning mechanism is designed to fuse the prediction results of the base classifier to obtain the final results. At the end of this paper, several groups of experiments are organized. More than 10 public datasets and representative related algorithms are used for verification. Experimental results show that the proposed algorithm is significantly better in four performance metrics, such as AUC (Area Under Curve) and F-measure.
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轻量化目标检测模型SSD-MV3(Single Shot Detection-MobileNet V3)因输入图像尺寸限制无法直接检测高分辨率大尺寸合成孔径声纳(Synthetic Aperture Sonar, SAS)图像中感兴趣小目标.为此,本文提出了一种新的目标检测方法HRSSD(High Resolution Single Shot Detection),该方法通过冗余切割确保SSD-MV3输入图像尺寸的规范以及感兴趣小目标的完整,并利用二次非极大值抑制保证检测结果的唯一.此外,提出了一种尺度、空间和通道注意力机制联合的特征提取模块,并利用该模块重新设计了SSD-MV3的基础网络和附加特征提取网络,记作SSD-MV3P(Single Shot Detection-MobileNet V3 Pro),使得SSD-MV3P能更有效的感知感兴趣小目标特征信息.实验结果表明,在感兴趣小目标检测数据集SST(Sonar Small Targets)上,SSD-MV3P的平均检测精度(mean Average Precision, mAP)比SSD-MV3提升4.39%. HRSSD实现了高分辨率大尺寸SAS图像感兴趣小目标的检测,并且保证了同一位置上检测结果的完整性和唯一性.
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The efficient object detection model SSD-MV3 (Single Shot Detection-MobileNet V3) cannot directly detect the interested small targets in high-resolution SAS (Synthetic Aperture Sonar) images due to the input image size limit. To this end, this paper proposes a novel object detection method, HRSSD (High Resolution Single Shot Detection), which ensures the specification of SSD-MV3 input image size and the integrity of the interested small targets through redundant cutting algorithm, and guarantees the unique detection result by using secondary non-maximum suppression. Furthermore, an improved feature block with a combination of scale, space and channel attention mechanism is proposed, and the basic network and additional feature network of SSD-MV3 are redesigned as SSD-MV3P (Single Shot Detection-MobileNet V3 Pro). Thus, SSD-MV3P can more effectively perceive the feature information of interested small targets. The experimental results show that the mAP (mean Average Precision) of SSD-MV3P is 4.39% higher than that of SSD-MV3 on the interested small target detection dataset SST (Sonar Small Target). HRSSD realizes the detection of the interested small targets in high-resolution SAS images, and ensures the integrity and uniqueness of the detection result at the same location.
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随着车联网的迅猛发展,车对路基础设施(Vehicle to Infrastructure,V2I)通信对车联网的可靠性和时延提出了更高的要求,而信道估计是接收机高可靠低时延通信的重要保障.为解决传统信道插值算法不能有效拟合V2I信道快时变特性、自适应多普勒频移能力弱和传统神经网络可解释性不强的问题,本文提出基于图神经网络(Graph Neural Network,GNN)的单载波频分多址(Single Carrier-Frequency Division Multiple Access,SC-FDMA)智能信道估计算法.该算法将信道频率响应中的数据点作为图的节点、符号间时域相关性作为边,将图化后的数据送入GraphSAGE信道插值器(GraphSAGE Channel Interpolator,GCI)中,通过边更新、聚合操作、节点更新三大模块进行网络训练,同时采用多普勒频移矢量作为节点特征控制网络拟合不同多普勒条件的信道,使得网络具备可解释性.最后,系统仿真验证了在不同速度环境下算法的有效性和鲁棒性,较线性插值、样条插值以及全连接网络,本文所提GCI在低、中和高速移动环境下具有最优的误码率(Bit Error Rate,BER)和归一化均方误差(Normalized Mean Square Error,NMSE)性能,特别地,在200 km/h高速移动条件下GCI的优势更为明显.
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With the rapid development of the Internet of vehicles, vehicle to infrastructure (V2I) communication puts forward higher requirements for the reliability and delay of vehicle networking. Channel estimation is an important guarantee for high reliable and low-latency communication of receiver. To solve the problems that the traditional channel interpolation algorithm cannot effectively fit the fast time-varying characteristics of V2I channel, the ability of adaptive Doppler frequency shift is weak, and the interpretability of traditional neural network is not strong, this paper presents a single carrierfrequency division multiple access (SC-FDMA) intelligent channel estimation algorithm based on graph neural network (GNN). The proposed algorithm takes the data points in the channel frequency response as the nodes of the graph and the inter-symbol time domain correlation as the edges. The graphical data is fed into the GraphSAGE channel interpolator (GCI). The network training is carried out through the three modules of edge update, aggregation operation and node update. At the same time, the Doppler shift vector is used as the node feature control network to fit the channels with different Doppler conditions, making the network interpretable. Finally, the system simulation verifies the effectiveness and robustness of the algorithm in different speed environments. Compared with linear interpolation, spline interpolation and fully connected network, the proposed GCI has the best performance of bit error rate (BER) and normalized mean square error (NMSE) in low, medium and high-speed mobile environments, especially, the advantage of GCI is more obvious under the condition of 200 km/h high-speed movement.
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针对工业互联网安全态势评估存在数据特征提取困难和安全态势评估准确率低等难题,提出一种基于改进随机森林的工业互联网安全态势评估方法.基于随机采样技术平衡原始数据集以减小不平衡数据集对实验的影响;利用梯度提升决策树确定工业互联网流量数据中不同特征的权重系数,结合递归特征消除法提取其关键特征;构建基于改进随机森林的工业互联网多分类攻击检测模型,识别网络受到的攻击类别,并结合安全态势量化指标确定其风险程度.实验结果表明,本文算法的检测准确率和F1值分别达到89.19%和89.68%,相较于传统随机森林算法、支持向量机和K最近邻算法,其准确率和F1值分别至少提高2.91%和1.7%,平均分别提高8.38%和9.33%.
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Aiming at the difficulties of data feature extraction and low accuracy of industrial Internet security situation assessment method, a method of security situation assessment based on improved random forest for industrial Internet is proposed. The original data set is balanced based on random sampling technique to reduce the influence of unbalanced data set on the experiment. The gradient boosting decision tree is used to determine the weight coefficients of different features in industrial Internet traffic data, and the key features are extracted by the recursive feature elimination method. Construct a multi-classification attack detection model for the industrial Internet based on improved random forest, identify the types of attacks on the network, and determine the degree of risk in combination with the quantitative indicators of security situation. The experimental results show that the detection accuracy and F1 score of this algorithm reach 89.19% and 89.68% respectively. Compared with the traditional random forest algorithm, support vector machine and k-nearest neighbor algorithm, the accuracy and F1 score are improved by at least 2.91% and 1.7% respectively, with an average increase of 8.38% and 9.33%.
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随着非正交多址接入(Non-Orthogonal Multiple Access, NOMA)技术的不断发展,协作NOMA(Cooperative Non-Orthogonal Multiple Access, CNOMA)也受到广泛关注.该文研究了由一个基站(Base Station, BS)、一个远端用户和一个近端用户组成的全双工(Full-Duplex, FD)协作NOMA(FD-CNOMA)系统,其中近端用户作为一个FD解码转发中继以传输远端用户的信号.考虑实际情况中存在基站与远端用户有无直接链路两种情况,以及非理想连续干扰消除(Successive Interference Cancellation, SIC)对系统带来的残留干扰问题,该文提出并解决了在该模型下用户的功率分配问题.最后,该文基于此模型给出了中继用户和远端用户的中断概率闭式表达式和遍历速率的近似闭式表达式.理论分析与仿真结果表明,即便存在非理想SIC和自干扰,相对于半双工(Half-Duplex, HD)协作NOMA(HDCNOMA)和NOMA系统而言,FD-CNOMA系统表现出更好的系统性能.同时,非理想SIC和中继用户自干扰都会对用户性能产生负面影响,且非理想SIC在遍历速率上对HD机制的影响较FD机制更为严重.最后,文中提出的功率分配方法较随机功率分配和固定功率分配分别获得了13%和10%的速率提升.
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With the development of non-orthogonal multiple access (NOMA) technology, cooperative non-orthogonal multiple access (CNOMA) has received extensive attention. This paper investigates a full-duplex (FD) cooperative NO-MA (FD-CNOMA) system, including one base station (BS), one near user, and one far user, where the near user acts as one FD relay to transmit the signal of the far user. Considering whether there is a direct link between the BS and the far user, and the residual interference caused by imperfect successive interference cancellation (SIC), the task of user power allocation under this model is also addressed in this paper. Finally, based on this model, we derive the closed-form expression of the outage probability and the average rate of the relay user and the far user. Theoretical analysis and simulation results show that the FD-CNOMA system performs better than the half-duplex (HD) cooperative NOMA (HD-CNOMA) and NO-MA systems, even in the presence of imperfect SIC and self-interference. At the same time, both imperfect SIC and relay user self-interference have negative effects on user performance, and the effect of imperfect SIC on the ergodic rate of the HD mechanism is more notable than that of the FD mechanism. Finally, compared with random and fixed power allocation, the proposed power allocation method achieves 13% and 10% system sum-rate improvement respectively.
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针对多链式区块链采用主链最终共识机制,导致主链负载大,制约从链性能等问题,论文提出一种基于超图和MuSig2聚合签名的联盟链主从多链共识机制.首先根据超图理论,构建以横贯超图为主链,子超图为从链的联盟链主从多链架构;然后借鉴分治思想,结合“背书-排序-验证”的共识方式,构建分层分类共识机制,通过分类处理交易降低主链负载压力;最后构建基于MuSig2聚合签名的联盟链多方背书签名方法,提升背书签名的验证效率.性能分析表明:基于MuSig2聚合签名的联盟链多方背书签名安全可靠,基于超图和MuSig2聚合签名的分层分类共识机制具有强一致性和线性时间复杂度.实验结果表明:基于MuSig2聚合签名的多方背书方法的总效率是椭圆曲线数字签名算法(Elliptic Curve Digital Signature Algorithm,ECDSA)的1.55倍,分层分类共识机制能够提升12.5%的共识效率.该机制具有较高性能,可满足企业多样化业务需求.
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To solve the problems of multi-chain blockchain using the final consensus mechanism of the main blockchain, resulting in a large load on the main blockchain and restricting the performance of the slave blockchain, a masterslave multi-chain consensus mechanism of the consortium blockchain based on hypergraph and MuSig2 aggregate signature is proposed. Firstly, according to the hypergraph theory, a master-slave multi-chain architecture of the consortium blockchain with the transverse hypergraph as the main blockchain and the sub-hypergraph as the slave blockchain is constructed. Then, drawing on the divide and conquer ideology, combined with the consensus mode of“ endorsement-sorting-verification”, a hierarchical classification consensus mechanism is constructed to reduce the load pressure of the main chain through classification processing transactions. Finally, a multi-party endorsement signature method based on MuSig2 aggregate signature is constructed to improve the verification efficiency and performance of endorsement signatures. Performance analysis shows that the multi-party endorsement signature of the consortium blockchain based on MuSig2 aggregate signature is safe and reliable, and the hierarchical classification consensus mechanism based on hypergraph and MuSig2 aggregate signature has strong consistency and linear time complexity. Experimental result shows that the total efficiency of the multi-party endorsement method based on MuSig2 aggregate signature is 1.55 times that of elliptic curve digital signature algorithm(ECDSA), and the hierarchical classification consensus mechanism can improve the consensus efficiency by 12.5%. This mechanism has high performance and can meet the diversified business needs of enterprises.
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针对现有IEEE 802.1AS协议中单一主时钟无法保障多跳网络下高精度同步的问题,提出一种基于多属性决策的冗余时钟同步方法.首先,基于链路拥塞程度、节点拓扑属性和时钟源质量系数对时钟属性值进行建模;其次,采用多属性决策算法选取最佳主时钟并生成冗余时钟序列表;最后,利用FPGA(Field Programmable Gate Array)平台设计并实现冗余时钟同步系统,同时搭建真实网络环境对所提方法进行测试.结果表明,相较于现有方法,时钟同步精度提升了68%,主时钟失效后重新同步所需收敛时间减小了60%.
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Aiming at the problem that a single master clock in the existing IEEE 802.1AS protocol cannot guarantee the high precision of clock synchronization in multi-hop network, a redundant clock synchronization method based on multiattribute decision-making is proposed. Firstly, the clock attribute value is modeled based on the link congestion degree, topology attribute of node and clock source quality factor. Secondly, the multi-attribute decision-making algorithm is used to select the best master clock and generate a redundant clock sequence table; Finally, the redundant clock synchronization system is designed and implemented on field programmable gate array (FPGA) platform, and a real network environment is constructed to test the proposed method. The results show that, compared with the existing methods, the clock synchronization accuracy is improved by 68%, and the convergence time required for resynchronization after master clock failure is reduced by 60%.
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非小细胞肺癌严重损害人类健康,早期非小细胞肺癌CT(Computed Tomography)图像中的肿瘤结节体积小,不易发现,极易造成漏诊和误诊.为了精确分割非小细胞肺癌CT图像中的小体积肿瘤结节,本文提出SOSNet (Small Object Segmentation Networks)自动分割模型,利用ResNet(Residual Network)基础层和空洞卷积构造非对称编码器-解码器结构作为分割主网络,利用轴向取反注意力模块ARA(Axial Reverse Attention)逐步擦除背景中对分割有影响的结构,再使用结构细化模块SR(Structure Refinement)对主网络输出的粗略特征图进行结构细化,从而实现非小细胞肺癌肿瘤结节分割.在非小细胞肺癌公开数据集的实验测试表明,本文提出的小目标自动分割模型SOSNet可以有效分割出非小细胞肺癌CT图像中的小体积肿瘤结节,其mDice(mean-Dice)、mIoU(mean Intersection over Union)、Sensitivity、F1、Specificity、平均绝对误差MAE(Mean Absolute Error)均优于当前最先进的小目标分割模型CaraNet(Context Axial Reverse Attention Network).
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Non-small cell lung cancer (NSCLC) will imperil human health seriously. The tumor nodules at the early stage of NSCLC are so small that it is very difficult to detect them in the CT (Computed Tomography) images, which will easily lead to the missed diagnosis and misdiagnosis of NSCLS. To automatically segment the small tumor nodules in CT images of NSCLC accurately, the SOSNet (Small Object Segmentation Networks) model is proposed. The ResNet (Residual Network) base layer and the dilated convolution are adopted to construct the asymmetric encoder-decoder structure to be the segmentation main network of SOSNet. The ARA (Axial Reverse Attention) module is adopted to gradually erase those structures which may influence the segmentation results from the background. Then the SR (Structure Refinement) module is used to refine the rough feature maps outputted by the main network, so as to achieve the segmentation for NSCLC tumor nodules. Experimental results on the open access NSCLC datasets demonstrate that the proposed SOSNet model can effectively segment small volume tumor nodules in CT images of NSCLC. It is superior to the state-of-the-art small object segmentation model of CaraNet in terms of mDice (mean Dice), mIoU (mean Intersection over Union), Sensitivity, F1, Specificity and MAE (Mean Absolute Error), respectively.
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轮询是一种依次有序服务的系统资源动态调度机制.针对服务器在站点间查询、服务和转移过程中的流水线作业方式导致了系统整体服务效率较低的问题,本文提出了完全服务的并行优化轮询系统.首先,构建了系统的单服务器多队列排队模型和相应的系统状态方程,并精确解析出系统特性参数的完整数学解析表达式.此外,还提出了一种系统状态稳定性的判定方法,对不同负载状态下的系统稳定性进行了定量分析.计算机仿真的统计分析结果与理论计算值相一致.最后,系统性能分析表明,在保持周期性、无冲突服务的基础上,系统的队长、时延特性和稳定状态下负载能力均得到了较大的提高.
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Polling is a dynamic scheduling mechanism of system resources with orderly services. Considering the low service efficiency of the whole system in the pipelining process of the server, this paper proposes a novel system of parallel optimization polling based on an exhaustive service policy. Firstly, the systematic single-server multi-queue queuing model and its equations of state transfer are constructed. Secondly, the complete mathematical analytical expressions of the system characteristic parameters are accurately analyzed. In addition, this paper attempts a method to quantitatively analyze the system stability under different load states. The statistical analysis result of the computer is consistent with the theoretical calculation value. Moreover, the system performance analysis shows that the queuing length, waiting delay characteristics and load capacity in steady state of the polling system have been greatly improved while maintaining periodic and conflict-free services.
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边缘计算安全的资源受限特征及各种新型密码技术的应用,对多核密码处理器的高能效、异构性提出需求,但当前尚缺乏相关的异构多核能效模型研究.本文基于扩展Amdahl定律,引入密码串并特征、异构多核结构、数据准备时间、动态电压频率调节等因素,将核划分空闲、活跃状态,建立异构多核密码处理器的能效模型. MATLAB仿真结果表明,数据准备时间占比小于10%时,对能效的负面影响大幅下降;固定电压,频率缩放会影响能效值大小;处理器核空闲/活跃能耗比例越小,能效值越大.架构上,固定异构核,同构核数量与密码任务最大并行度相等时能效值最大,最佳异构核数可由模型变化参数仿真得到;多任务调度执行上,流水与并发执行有利于能效值的进一步提升.多核密码处理器芯片板级测试结果表明,仿真结果与实测数据相关系数接近1,芯片实测的数据准备时间、电压频率缩放等因素的影响与仿真分析基本一致,验证了所提能效模型的有效性.该文重点从影响能效变化趋势因素上,为多核密码处理器异构、高能效设计提供一定的理论分析基础与建议.
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The resource constraints of Edge Computing security and application of new cryptography technologies require the high energy efficiency and heterogeneity of multi-core cryptoprocessors, but there is still a lack of energy-efficient model. Based on extending Amdahl's law, this paper introduces the feature of cipher, heterogeneous multicore structure, data preparation time, dynamic voltage and frequency scaling, divides cores into idle and active states, then builds the energyefficient model of heterogeneous multicore cryptoprocessor. MATLAB simulations show that the negative impact on energy efficiency is considerably reduced when the data preparation time is less than 10%. Fixed voltage and frequency scaling can affect the value of energy efficiency. The smaller the idle/active energy ratio of the processor core, the larger the energy efficiency value. On the architecture side, when the number of homogeneous cores is equal to the maximum parallelism of the cryptograph task, the energy efficiency value is largest when the number of heterogeneous cores is fixed, and the optimal number of heterogeneous cores can be simulated by varying the parameters of the model. In the execution of multi-task scheduling, pipelines and concurrent execution are beneficial to further increase the energy efficiency value. Board-level test results show that the correlation coefficient between simulation results and chip test data is close to 1, and the influence of measured data preparation time, voltage frequency scaling and other factors is essentially consistent with the simulation analysis, which verifies the effectiveness of the proposed energy efficiency model. In this paper, we focus on the factors affecting the energy efficiency trend and provide some theoretical analytical grounds and recommendations for heterogeneous and energy efficient design of multicore cryptographic processors.
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深度学习模型对对抗样本表现出脆弱性.作为一种对现实世界深度系统更具威胁性的攻击形式,物理域对抗样本近年来受到了广泛的研究关注.现有方法大多利用局部对抗贴片噪声在物理域实现对图像分类模型的攻击,然而二维贴片在三维空间的攻击效果将由于视角变化而不可避免地下降.为了解决这一问题,所提Adv-Camou方法利用空间组合变换来实时生成任意视角及变换背景的训练样本,并最小化预测类与目标类交叉熵损失,使模型输出指定错误类别.此外,所建立的仿真三维场景能公平且可重复地评估不同的攻击.实验结果表明,Adv-Camou生成的一体式对抗伪装可在全视角欺骗智能图像分类器,在三维仿真场景比多贴片拼接纹理平均有目标攻击成功率高出25%以上,对Clarifai商用分类系统黑盒有目标攻击成功率达42%,此外3D打印模型实验在现实世界平均攻击成功率约为66%,展现出先进的攻击性能.
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Deep learning models are vulnerable to adversarial examples. As a more threatening type for practical deep learning systems, physical adversarial examples have received extensive research attention in recent years. Most of the existing methods use the local adversarial patch noise to attack the image classification model in the physical world. However, the attack effect of 2D patches in 3D space would inevitably decline due to the change in the view angle. To address this issue, the proposed Adv-Camou method uses spatial combination transformation to generate training examples of arbitrary viewpoints and transformed backgrounds in real time. Moreover, the cross-entropy loss between the prediction class and target class is minimized to make the model output the specified incorrect class. In addition, the established 3D scene can evaluate different attacks fairly and reproducibly. The experimental results show that the coated adversarial camouflage generated by the Adv-Camou method can fool image classifiers from arbitrary viewpoints. In the 3D simulation scene, the average targeted attack success rate of Adv-Camou is more than 25% higher than that of piecing together patches. The success rate of black-box targeted attacks on the Clarifai commercial classification system reaches 42%. In addition, the average attack success rate of 3D printing model experiments in the real world is about 66%, which significantly demonstrates that our method outperforms state-of-the-art methods.
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片上网络(Network-on-Chip,NoC)在多处理器系统中得到了广泛的应用.近年来,有研究提出了基于NoC的深度神经网络(Deep Neural Network,DNN)加速器.基于NoC的DNN加速器设计利用NoC连接神经元计算设备,能够极大地减少加速器对片外存储的访问从而减少加速器的分类延迟和功耗.但是,若采用传统的单播NoC,大量的一对多数据包会极大的提高加速器的通信延迟.并且,目前的深度神经网络规模往往非常庞大,而NoC的核心数量是有限的.因此,文中提出了一种针对资源受限的NoC的组播方案.该方案利用有限数量的处理单元(Processor Element, PE)来计算大型的DNN,并且利用特殊的树形组播加速网络来减少加速器的通信延迟.仿真结果表明,和基准情况相比,本文提出的组播机制使加速器的分类延迟最高降低了86.7%,通信延迟最高降低了88.8%,而它的路由器面积和功耗仅占基准路由器的9.5%和10.3%.
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Network-on-Chip (NoC) devices have been widely used in multiprocessor systems. In recent years, NoCbased deep neural network (DNN) accelerators have been proposed to connect neural computing devices using NoCs. Such designs dramatically reduce off-chip memory accesses of these platforms thus reduce the accelerators’ classification latency and power consumption. However, the large number of one-to-many packet transfers significantly increase the communication latency with traditional unicast channels. We proposed a multicast mechanism for resource-constrained noc-based deep neural network accelerators (MRNDA) to compute large DNN models by using limited number of processor elements (PEs). This paper proposes a tree-based multicast acceleration network to decrease the communication latency of DNN accelerators. Simulation results show that, compared with the baseline method, the multicast mechanism proposed in this paper reduces the classification latency of the accelerator by up to 86.7% and the communication latency by up to 88.8%, while its router’s area and power only account for 9.5% and 10.3% of the baseline routers.
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少样本学习是目前机器学习研究领域的热点和难点.针对现有的少样本学习模型不能有效捕捉数据特征与数据标签之间的联系,造成分类模型泛化能力弱的问题,提出一种基于元学习的原型空间图卷积网络少样本学习模型FSL-GCNPS(Few-Shot Learning of Graph Convolutional Network on Prototype Space).首先,利用卷积神经网络提取多任务数据的特征向量;其次,为了将特征向量映射到原型空间中,根据元学习的训练策略得到特征向量的类原型表达;然后,通过类原型向量和类向量之间的嵌入表示,构建图结构数据,并进行图卷积网络训练、推理.实验结果表明,相较于经典少样本学习方法,FSL-GCNPS模型拥有更好的分类准确率和分类稳定性.同时,在医学图像领域数据集上实验表明,FSL-GCNPS具有很好的跨域适应性.
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Few shot learning is a hot and difficult problem in the field of machine learning. The existing few-shot learning model cannot effectively capture the relationships between data feature information and data label, thus causing the generalization ability of the resulting classifier would be weaker. A few-shot learning of graph convolutional network on prototype space, termed FSL-GCNPS, is developed. Firstly, the feature vectors are extracted on multi-task data by convolutional network. Secondly, in order to map the feature vectors into the prototype space, representation learning for the classes based on prototype network is proposed. Next, the graph is structured by combing the classes prototype vectors with class vectors. Then, FSL-GCNPS is trained using Meta learning. The experimental results show that FSL-GCNPS has better cross-domain adaptability in the medical image domain compared with the traditional deep learning models. Meanwhile, the FSL-GCNPS model has better classification accuracy and classification stability compared with the classical Few-shot learning algorithm.
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针对云环境下密文策略属性基加密方案中存在的密文检索分类困难与依赖可信第三方等问题,本文提出了一种基于区块链的多授权密文策略属性基等值测试加密方案.利用基于属性的等值测试技术,实现了支持属性级灵活授权的云端数据检索和分类机制,降低了数据用户对重复数据解密的计算开销.结合多授权属性基加密机制和区块链技术,实现了去中心化用户密钥生成.采用多属性授权机构联合分发密钥,有效抵抗用户和属性授权机构的合谋攻击.引入区块链和智能合约技术,消除了现有密文策略属性基密文等值测试方案中等值测试、数据存储与外包解密操作对可信云服务器的依赖.利用外包服务器执行部分解密计算,降低了用户本地的计算开销.将原始数据哈希和验证参数上传至区块链,保障外包服务器解密结果正确性和云端数据完整性.在随机预言模型下,基于判定性qparallel Bilinear Diffie-Hellman Exponent困难问题证明了本文方案在选择密文攻击下的单向性.与同类方案相比较,本文方案支持更多的安全属性,并具有较低的计算开销.
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Aiming at the problems of ciphertext retrieval classification difficulty and dependence on trusted third party in the ciphertext-policy attribute-based encryption schemes within cloud environment, a blockchain-based multi-authority ciphertext-policy attribute-based encryption scheme with equality test is proposed. The attribute-based encryption with equality test technology is used to retrieve and classify ciphertexts that supports attribute-level flexible authorization, which reduces the computational cost of data users to decrypt duplicate data. Combined with multi-authority attribute-based encryption and blockchain technology to achieve decentralized user key generation. Meanwhile, the key is jointly distributed by different authorized institutions can effectively resist collusive attacks by users and attribute authorization agencies. Blockchain and smart contract technology are introduced to eliminate the dependence of trusted cloud servers in the outsourcing decryption, data storage and equivalence test operation in the existing ciphertext-policy attribute-based encryption with equality testing schemes. Outsourced server is used to perform part of the decryption computation, which reduces the user's local calculation overhead. The original data hash and verification parameters are uploaded to the blockchain, which ensures the correctness of the outsourcing server's decryption results and the integrity of cloud data. Under the random oracle model, the oneway property of the proposed scheme under chosen-ciphertext attack is proved based on the decision q-parallel BDHE hard problem. Compared with similar schemes, the proposed scheme supports more security properties and has lower computational overhead.
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本文针对一类广泛存在的分布式加工装配和车辆配送集成调度问题(Integrated Scheduling Problem of Distributed Production Assembly and Vehicle Delivery,ISP_DPAVD),以最小化运输和延迟惩罚总成本为优化目标,提出一种混合三维分布估计算法(Hybrid three-Dimensional Estimation of Distribution Algorithm,H3DEDA)进行求解. ISP_DPAVD包含两个耦合的子问题,即加工装配阶段子问题(子问题1)和车辆配送阶段子问题(子问题2).由于每个子问题1的解(部分解1)均会确定1个具体的子问题2,故ISP_DPAVD的解空间非常庞大.根据这一特点,在H3DEDA中,先设计结合邻域变换的启发式规则来快速获取子问题2的优良解,以实现子问题间的部分解耦并明显缩减搜索空间,再设计三维EDA引导的全局搜索和变邻域驱动的局部搜索来获取ISP_DPAVD的高质量解.通过在不同规模测试问题上的仿真实验和算法比较,验证了H3DEDA求解ISP_DPAVD的有效性.
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This paper proposes a hybrid three-dimensional distribution estimation algorithm (H3DEDA) to minimize the total cost of transportation and delay penalties for a kind of widely existed integrated scheduling problem (ISP_DPAVD), which includes two coupled subproblems, i.e., the subproblem in the production and assembly stage (subproblem 1) and the subproblem in the vehicle distribution stage (subproblem 2). Since each solution of subproblem 1 determines a specific subproblem 2, the solution space of the ISP_DPAVD is very large. According to this characteristic, in H3DEDA (Hybrid three-Dimensional Estimation of Distribution Algorithm), the heuristic rules combined with neighborhood transformation are designed to quickly obtain the excellent solution of subproblem 2, so as to achieve partial decoupling between subproblems and significantly reduce the search space. Then, the global search guided by three-dimensional EDA and the local search driven by variable neighborhood operations are devised to acquire high-quality solution for the ISP_DPAVD. Simulation experiments and comparisons on the test problems with different scales verify the effectiveness of H3DEDA in solving ISP_DPAVD.
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当前,生成对抗网络(Generative Adversarial Networks, GAN)合成的逼真图像难以识别,严重危害国家网络安全及社会稳定.与此同时,多数基于深度神经网络模型设计的检测器需要大规模训练样本,且存在模型可解释度不高、泛化性能差等问题.为了克服上述亟待解决的关键性难题,本文提出一种多色彩通道特征融合的GAN合成图像检测方法.首先,探索分析真实自然图像和GAN合成图像在不同色彩空间相邻像素之间的差异,并设计差异度量算法,完成色彩通道选择.其次,利用图像像素间的高度相关性,在八个方向上通过二阶马尔可夫链对相邻像素之间的差分数组进行建模,提取差分像素邻接矩阵特征.最后,利用上述特征,设计一种简单且高效的集成分类器完成GAN合成图像的检测任务.在基于StyleGAN模型合成的伪造人脸数据集中,所提出方法的检测准确率高达100.00%;在小样本训练约束条件下,正负样本对数仅仅为2时,检测准确率高达99.65%;在单类样本训练约束条件下,正样本数仅仅为50时,检测准确率高达92.84%.在基于更先进的StyleGAN2和PGGAN模型合成的伪造场景数据集中,所提出方法的检测准确率达到99.96%以上.以上大量实验表明,本文所提出的方法明显优于比较的GAN合成图像检测方法.本文方法已经开源:https://github. com/cyxcyx559/ccss.
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Currently, it is very difficult to identify the images synthesized by generative adversarial networks (GAN), which severely poses the threat on national cyber security and social stability. Meanwhile, most classifiers based on deep neural networks require large-scale samples for training, where the problems such as low model interpretability and poor generalization performance are less addressed. To overcome the limitations, we propose to design the ensemble classifier using fused features in the multi-color channels. First of all, by studying the discrimination of adjacent pixels in the multi-color channels between natural and GAN synthetic images, the difference metric is designed based on the correlation of adjacent pixels, in order to select the optimal color channels. Secondly, by utilizing the highly-correlated relationship among pixels, the difference array between adjacent pixels are modeled through a second-order Markov chain along eight directions, and meanwhile the subtractive pixel adjacency matrix features are successfully extracted. Finally, based on the extracted features, a simple but efficient detector for identifying GAN synthetic images is constructed. In the image dataset synthesized by the StyleGAN model, the results show that the accuracy of the proposed detector can reach 100.00%. It can also identify GAN synthetic images very well when the pair number of positive and negative training samples is 2 (99.65% accuracy) or only 50 positive training samples are provided (92.84% accuracy). The accuracy can also reach more than 99.96% in the image dataset synthesized by StyleGAN2 and PGGAN models. Numerous experiments show that the proposed method in this paper is better than the compared forensic methods. Our code is available at https://github.com/cyxcyx559/ccss.
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针对现有轻量级模型在嵌入式设备的人脸识别应用中存在识别精度难以提升的问题,提出一种融合人脸对齐关键特征点信息的轻量级新残差网络模型(Lightweight New Residual Network, LNRN). LNRN利用深度残差网络结构能够解决网络退化且避免干扰因素影响的优势,结合人脸对齐环节产生的关键特征点信息,对深度残差网络结构进行简化和合理设计,实现对关键特征信息和全局信息的提取.为避免特征提取过程中丢失重要特征信息,该模型在新残差网络中加入结合空间和通道的注意力机制进行辅助.在公开的四个标准人脸数据集上的仿真实验表明,该模型识别速度在接近主流轻量级人脸识别方法的同时,平均识别精度比MobiFace提高了0.6%.
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Aiming at the problem that the existing lightweight models are difficult to improve the recognition accuracy in the face recognition applications of embedded devices, a new lightweight residual network model (Lightweight New Residual Network, LNRN) that integrated the key feature point information of face alignment is proposed. The advantage of deep residual network structure that can solve the network degradation and avoid the influence of interference factors are absorbed by LNRN. In order to realize the extraction of key feature information and global information after combining the key point information generated by the face alignment, the deep residual network structure is simplified and reasonably designed. In order to avoid losing important feature information in the process of feature extraction, an attention mechanism combining space and channel is added to the new residual network for assistance. Simulation experiments on the four standard face datasets showed that the recognition speed of the proposed model was close to the mainstream lightweight face methods, and the average recognition accuracy of the proposed model is 0.6% higher than that of MobiFace.
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循环神经网络对于代码序列数据有着良好的处理能力,软件缺陷修复的补丁生成模型大多采用循环神经网络实现.然而,基于循环神经网络的补丁生成模型在处理代码序列中长距离依赖问题时仍然具有局限性,其修复成功率和修复效率较低.针对此问题,提出一种基于自注意力神经机器翻译的软件缺陷自动修复方法(Self-attention Neural machine translation based automatic software Repair,SNRepair).首先,为有效缓解源码中的未登录词问题,对数据集引入子词切分技术进行预处理;其次,为解决源代码中棘手的长距离依赖问题并更充分地利用局部信息,构建融合局部建模的Transformer程序补丁生成模型;然后,采用缺陷自动定位技术定位缺陷语句位置,利用参数优化后的Transformer补丁生成模型生成候选补丁;最后,运行测试用例验证候选补丁.在具有395个真实Java软件缺陷的Defects4J缺陷库上实验评估,结果表明SNRepair方法与对比方法比较,修复成功率和修复效率更高.
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Recurrent neural network has good ability of the processing for code sequences, and the patch generation model is mostly implemented by it. However, recurrent neural network-based patch generation models still have some limitations when dealing with long-distance dependencies in code sequences, and their repair success rate and repair efficiency is low. To address the issue, we present SNRepair, an automatic software fault repair based on self-attention neural machine translation. First, the subword tokenization technology is introduced to preprocess the dataset to alleviate the problem of out of vocabulary. Second, a Transformer program patch generation model that integrates local modeling is constructed to alleviate the long-distance dependencies in the source code and make better use of local information. Third, the automatic fault localization technology is used to locate the possible fault position and the Transformer patch generation model through parameter optimization is adopted to generate candidate patches. Finally, the candidate patches are verified by test cases. On the 395 real Java software faults in the Defects4J, the results show that the SNRepair has higher repair success rate and repair efficiency than the compared ones.
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局部修复码是一种通过局部修复提高存储节点修复效率的重要编码方法,在分布式存储和云存储中有重要应用.本文首先构造了几类维数为4或5的near MDS(near Maximum Distance Separable)码,精确计算出了它们的参数和重量分布.特别地,得到了一些参数相同但重量分布不同的near MDS码.此外,通过确定near MDS码的局部度,得到了几类距离最优和维数最优的局部修复码.这些局部修复码的参数和文献中已知最优局部修复码的参数不同.
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Locally recoverable codes offer an efficient way to improve the repair efficiency of storage nodes by local recovery. They are widely used in distributed storage and cloud storage. In this paper, we first present several constructions of near MDS (near maximum distance separable) codes of dimension 4 or 5. The parameters and weight distributions of the codes are explicitly determined. In particular, some families of near MDS codes with the same parameters but different weight distributions are derived. Then the locality of the near MDS codes is also studied. Several families of distance-optimal and dimension-optimal locally recoverable codes are obtained. These locally recoverable codes have different parameters from those of known ones in the literature.
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Android系统是目前主流的移动终端操作系统之一,其数据泄露问题日益受到学术界的广泛关注.恶意应用窃取用户敏感数据后通过互联网发送扩散,从而对用户实施进一步侵害. Android系统中网络权限属于常规权限,应用无需用户授权即可联网发送数据.针对上述问题,本文提出了一种基于Android内核驱动程序的网络白名单网络控制方案,用户可以监控所有应用程序的网络使用状态,选择信任的应用加入白名单中,对白名单中的应用程序实行内核级签名验证,防止程序代码被非法篡改,从而构建安全可控的网络使用环境.本方案为应用和内核的通信构建了专用通道,以确保网络白名单管理权限不会被其他应用窃取,随后通过进程识别针对性地管控网络权限,在不影响正常应用功能的情况下实现权限管理.经过实验验证,本方案可以有效防止恶意应用利用互联网泄露用户隐私,网络管控成功率达到了100%.系统运行稳定,被管控应用启动时间最大增加33.1%,最小增加3.6%.
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Android system is one of the most popular mobile terminal operating systems at present, and its data leakage problem has been increasingly concerned by the academic community. Malwares steal users’ sensitive data and spread it over the Internet to harm users further. In the Android system, network permissions belong to common permissions, and applications can send data by internet without user authorization. To solve the above problems, this paper proposes a network whitelist scheme to control network based on Android kernel driver. Users can monitor the network usage status of all applications and select trusted applications to be added to the whitelist, and a kernel-level signature verification for applications in the whitelist is applied to prevent illegal tampering of execution code, thereby creating a safe and controllable network usage environment. A dedicated channel is constructed for the communication between applications and the kernel to ensure that the network whitelist management permissions are not acquired by other applications. Then, the network permissions are controlled through process identification to achieve permission management without affecting normal application functions. Through experimental verification, this scheme can effectively prevent malwares from using the Internet to leak users' privacy data, and the success rate of network control has reached 100%. The system runs stably and the startup time of controlled applications increases by a maximum of 33.1% and a minimum of 3.6%.
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针对传统近邻传播聚类算法以数据点对之间的相似度作为输入度量,由于需要预设偏向参数p和阻尼系数λ,算法精度无法精确控制的问题,提出了一种跳跃跟踪麻雀搜索算法优化的交叉迭代近邻传播聚类方法.首先,针对麻雀搜索算法中发现者和加入者位置更新不足的问题,设计了一种跳跃跟踪优化策略,通过考虑偏好阻尼因子的跳跃策略设计大步长更新发现者,增加麻雀搜索算法的全局勘探能力和寻优速度,加入者设计动态小步长跟踪领头雀更新位置,同时,利用自适应种群划分机制更新发现者和加入者的比重,增加算法的后期局部开发能力和寻优速度;其次,设计基于扰动因子的Tent映射,在此基础上增加3个参数,使映射分布范围增大,并避免了陷入小周期点和不稳周期点;最后,引入轮廓系数作为评价函数,跳跃跟踪麻雀搜索算法自动寻找较优的p和λ,代替手动输入参数,并融合基于扰动因子的Tent映射优化近邻传播算法,交叉迭代确定最优簇数.使用多种算法聚类University of California Irvine数据集的10种公共数据集,仿真结果表明,本文提出的聚类算法与经典近邻传播算法、基于差分改进的仿射传播聚类算法、基于麻雀搜索算法优化的近邻传播聚类算法和进化近邻传播算法相比具有更优的搜索效率以及聚类精度.对国家信息数据进行了聚类分析,提出的方法更加准确有效合理,具有较好的应用价值.
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Aiming at the problem that the traditional affinity propagation (AP) clustering algorithm takes the similarity between data points as the input measure, and the accuracy of the algorithm cannot be accurately controlled due to the need to preset the preference (p) and the damping coefficient (λ), a jump tracking sparrow search algorithm (JTSSA) optimized hybrid iterative AP clustering method (JTSSA-AP) is proposed. Firstly, in order to solve the problem of insufficient update of the position of the producers and the scroungers in sparrow search algorithm (SSA), a jump tracking optimization strategy is designed. By considering the preference factor, the jump strategy updates the producers in a large step, which increases the global exploration ability and optimization speed of SSA algorithm. The scroungers dynamically track the update position of the leading sparrow in a small step, and uses the adaptive population division mechanism to update the proportion of the producers and the scroungers, which increases the late local development ability and optimization speed of the algorithm. Secondly, on the basis of the original Tent mapping, the disturbance factor is added and three parameters are added, so that the mapping distribution range is increased and the small periodic point and unstable periodic point are avoided. Finally, the silhouette index is introduced as the evaluation function, JTSSA is designed to automatically find better p and λ instead of manual input parameters, the tent map based on disturbance factor optimize the AP clustering, and the optimal number of clusters is determined by hybrid iteration. Multiple algorithms are utilized to cluster the 10 public datasets of the university of California Irvine dataset. Simulation results indicate that the proposed clustering algorithm in this paper exhibits superior search efficiency and clustering accuracy compared to the AP algorithm, the AP clustering algorithm based on differential evolution, the AP clustering algorithm optimized by SSA, and the evolutionary affinity propagation. Cluster analysis is conducted on country data, and the proposed method demonstrates greater accuracy, effectiveness, and rationality, showcasing considerable practical value.
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图卷积由于其对图数据的强大表示能力被广泛应用于基于骨架的动作识别任务中.但是现有的图卷积方法在所有帧或通道上都使用共享的图拓扑进行特征聚合,这极大限制了图卷积网络的表示能力.为了解决这些问题,本文提出多维动态拓扑学习图卷积用于动态建模具有时序与通道特异性的拓扑结构.多维动态拓扑学习图卷积主要包含三个组成部分:纯粹节点拓扑学习图卷积(pure Joint topology learning Graph Convolution, J-GC)、动态时序特异性拓扑学习图卷积(Dynamic Temporal-Wise topology learning Graph Convolution, DTW-GC)和通道特异性拓扑学习图卷积(Channel-Wise topology learning Graph Convolution, CW-GC).特别地,在DTW-GC中使用了动态骨架拓扑建模方法(Dynamic Skeleton Topology Learning, DSTL),以高效地建模富含全局时空拓扑特征的动态骨架拓扑.将多维动态拓扑学习图卷积与多尺度时间卷积(Multi-Scale Temporal Convolution, MS-TC)相结合,本文构建了具有强大建模能力的图卷积网络.此外,为了对骨架数据的空间信息进行补充,本文额外引入了相对节点数据和相对骨骼数据进行多流网络的融合.本文所提出的方法在NTU-RGB+D与NTU-RGB+D 120数据集上分别取得了92.64%和89.29%的准确率,超过了当前最先进方法.
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Graph convolution is widely used in skeleton-based action recognition because of its effectiveness of processing graph data. However, the existing graph convolution methods use the shared graph topology for feature aggregation on all frames or channels, which greatly limits the representation ability of graph convolution network. In order to solve these problems, a multi-dimensional dynamic topology learning graph convolution is proposed in this paper to dynamically model the topology with temporal and channel specificity. The multi-dimensional dynamic topology learning graph convolution mainly includes three parts: pure joint topology learning graph convolution (J-GC), dynamic temporal-wise topology learning graph convolution (DTW-GC) and channel-wise topology learning graph convolution (CW-GC). In particular, in DTW-GC, a dynamic skeleton topology modeling method (DSTL) is designed to efficiently model the dynamic skeleton topology with rich global spatio-temporal topological features. Finally, by combining multi-dimensional dynamic topology learning graph convolution with multi-scale temporal convolution (Muti-Scale TCN), a graph convolution network with powerful modeling capability is constructed in this paper. In addition, in order to supplement the spatial information of skeleton data, the relative joint data and relative bone data are introduced for multi-stream network fusion. Our method achieves 92.64% and 89.29% accuracy on NTU-RGB+D and NTU-RGB+D 120 datasets, respectively, which is superior to the current state-of-the-art methods.
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无线医疗传感器网络的出现为患者的治疗带来了极大的便利.但是,无线医疗传感器网络中往往都使用不可信的公共信道进行数据通信并且只有唯一的云服务器处理大量的医疗数据,这就导致了通信安全、隐私保护、密钥泄露、云服务器计算负担过大、延迟高等问题.此外,现有的大多数无证书聚合签名方案无法抵抗完全选择密钥攻击.针对上述问题,本文提出一种适用于无线医疗传感器网络基于边缘计算的无证书并行密钥隔离聚合签名方案.方案引入边缘计算的架构使得签名的验证和聚合过程在更靠近终端用户的边缘层进行,在降低中心云服务器计算负担的同时还能有效的保护患者的隐私.本文方案继承了无证书和密钥隔离技术的优点,同时避免了复杂的证书管理、密钥托管以及密钥暴露等问题.在随机预言模型下证明了本文方案可以抵抗完全选择密钥攻击、Type I攻击以及Type II攻击.性能分析表明,与相关无证书签名方案相比,本文方案的计算开销至少可降低74.03%,通信开销至少可降低25%.
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The emergence of wireless medical sensor networks has brought great convenience to the treatment of patients. However, in wireless medical sensor networks, untrusted public channels are often used for data communication and only a single cloud server processes a large amount of medical data, which leads to communication security, privacy preservation, key leakage, excessive computational burden on the cloud server, and high latency. In addition, most existing certificateless aggregate signature schemes are unable to resist fully chosen-key attacks. Therefore, to address the above problems, a certificateless parallel key isolation aggregate signature scheme based on edge computing for wireless medical sensor networks is proposed. The scheme uses the architecture of edge computing so that the verification and aggregation process of signatures is carried out at the edge layer closer to the end-user, which can reduce the computing burden of the central cloud server and ensure effective privacy protection. The proposed scheme inherits the advantages of certificateless and key isolation, while avoiding complex certificate management, key escrow, and key exposure. Under the random oracle model, it is proved that the proposed scheme can resist fully chosen-key attacks, Type I attacks, and Type II attacks. The performance analysis shows that, compared with the related certificateless signature scheme, the computational efficiency of the proposed scheme can be reduced by at least 74.03%, and the communication overhead can be reduced by at least 25%.
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小目标检测是计算机视觉中极具挑战性的任务.它被广泛应用于遥感、交通、国防军事和日常生活等领域.相比其他视觉任务,小目标检测的研究进展相对缓慢.制约因素除了学习小目标特征的内在困难,还有小目标检测基准,即小目标检测数据集的稀缺以及建立小目标检测评估指标的挑战.为了更深入地理解小目标检测,本文首次对基于深度学习的小目标检测基准进行了全新彻底的调查.系统介绍了现存的35个小目标数据集,并从相对尺度和绝对尺度(目标边界框的宽度或高度、目标边界框宽高的乘积、目标边界框面积的平方根)对小目标的定义进行全面总结.重点从基于交并比及其变体、基于平均精度及其变体以及其他评估指标这3方面详细探讨了小目标检测评估指标.此外,从锚框机制、尺度感知与融合、上下文信息、超分辨率技术以及其他改进思路这5个角度对代表性小目标检测算法进行了全面阐述.与此同时,在6个数据集上对典型评估指标(评估指标+目标定义、评估指标+单目标类别)下的代表性小目标检测算法进行性能的深入分析与比较,并从小目标检测新基准、小目标定义的统一、小目标检测新框架、多模态小目标检测算法、旋转小目标检测以及高精度且实时的小目标检测这6个方面指出未来可能的发展趋势.希望该综述可以启发相关研究人员,进一步促进小目标检测的发展.
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Small object detection is an extremely challenging task in computer vision. It is widely used in remote sensing, intelligent transportation, national defense and military, daily life and other fields. Compared to other visual tasks such as image segmentation, action recognition, object tracking, generic object detection, image classification, video caption and human pose estimation, the research progress of small object detection is relatively slow. We believe that the constraints mainly include two aspects: the intrinsic difficulty of learning small object features and the scarcity of small object detection benchmarks. In particular, the scarcity of small object detection benchmarks can be considered from two aspects: the scarcity of small object detection datasets and the difficulty of establishing evaluation metrics for small object detection. To gain a deeper understanding of small object detection, this article conducts a brand-new and thorough investigation on small object detection benchmarks based on deep learning for the first time. The existing 35 small object detection datasets are introduced from 7 different application scenarios, such as remote sensing images, traffic sign and traffic light detection, pedestrian detection, face detection, synthetic aperture radar images and infrared images, daily life and others. Meanwhile, comprehensively summarize the definition of small objects from both relative scale and absolute scale. For the absolute scale, it mainly includes 3 categories: the width or height of the object bounding box, the product of the width and height of the object bounding box, and the square root of the area of the object bounding box. The focus is on exploring the evaluation metrics of small object detection in detail from 3 aspects: based on IoU (Intersection over Union) and its variants, based on average precision and its variants, and other evaluation metrics. In addition, in-depth analysis and comparison of the performance of some representative small object detection algorithms under typical evaluation metrics are conducted on 6 datasets. These categories of typical evaluation metrics can be further subdivided, including the evaluation metric plus the definition of objects, the evaluation metric plus single object category. More concretely, the evaluation metrics plus the definition of objects can be divided into 4 categories: average precision plus the definition of objects, miss rate plus the definition of objects, DoR-AP-SM (Degree of Reduction in Average Precision between Small objects and Medium objects) and DoR-APSL (Degree of Reduction in Average Precision between Small objects and Large objects). For the evaluation metrics plus single object category, it mainly includes 2 types: average precision plus single object category, OLRP (Optimal Localization Recall Precision) plus single object category. These representative small object detection methods mainly include anchor mechanism, scale-aware and fusion, context information, super-resolution technique and other improvement ideas. Finally, we point out the possible trends in the future from 6 aspects: a new benchmark for small object detection, a unified definition of small objects, a new framework for small object detection, multi-modal small object detection algorithms, rotating small object detection, and high precision and real time small object detection. We hope that this paper could provide a timely and comprehensive review of the research progress of small object detection benchmarks based on deep learning, and inspire relevant researchers to further promote the development of this field.
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慢性瘙痒是多种疾病的共同症状,严重影响患者的生活质量。瘙痒发生机制复杂,病因诊断与治疗常面临挑战。为提升我国临床医生对慢性瘙痒的认识,规范诊治行为,中国医师协会皮肤科医师分会组织国内部分专家,在我国《慢性瘙痒管理指南(2018版)》的基础上,基于国内外研究现状与进展,对慢性瘙痒的分类、病因及机制等方面进行了更新,并通过德尔菲法广泛征询专家意见,为慢性瘙痒的病因诊断与治疗方案提供专家意见与循证医学证据。
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Chronic pruritus is a common symptom of various diseases, causing severe negative impacts on patients′ quality of life. Due to its complex pathogenesis, etiological diagnosis and treatment are often challenging. To improve the understanding of chronic pruritus among Chinese clinicians and to standardize diagnosis and therapeutic practices, the China Dermatologist Association organized experts in China to update the classification, etiology, and pathogenesis of chronic pruritus based on the "Guidelines for the Management of Chronic Pruritus (2018 edition)", current research status and progress in China and other countries, as well as extensive consultation with experts in China through the Delphi method, aiming to provide expert opinions and evidence-based medical guidance on the etiological diagnosis and treatment of chronic pruritus.
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乳房外Paget病是一种少见且易误诊的皮肤恶性肿瘤,其早期病变局限于表皮,也可浸润至真皮层,晚期则可能出现淋巴结转移和远处转移。乳房外Paget病常见于大汗腺分布区域,包括阴囊、阴茎、外阴以及肛周、腹股沟、腋窝等部位,常表现为红色斑片或浸润性斑块,部分皮损伴有鳞屑、糜烂等。在选择治疗方案前,必须对患者进行全面的分期评估。本专家共识基于国际上最新的指南和临床研究成果,结合我国的临床治疗实践,形成了关于乳房外Paget病分期治疗的一线和二线治疗方案以及新型治疗方法,为规范乳房外Paget病的治疗提供依据。
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Extramammary Paget′s disease (EMPD) is a rare and easily misdiagnosed cutaneous malignancy, which is usually confined to the epidermis and can also infiltrate the dermis in the early stage, and presents with lymph node and distant metastases in the advanced stage. EMPD mostly affects the areas rich in apocrine glands, including the scrotum, penis, and vulva, as well as perianal, inguinal and axillary regions. It typically presents as infiltrative erythema or plaques, some of which are accompanied by scales and erosions. Before the treatment, comprehensively assessing the staging of patients is necessary due to the treatment options depending on the tumor stages. Based on the latest international guidelines and clinical research findings, and taking into account the current status of diagnosis and treatment in China, experts reached a consensus on the firstand second-line treatments and novel treatments according to the staging of EMPD, providing a basis for standardizing the treatment of EMPD.
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红皮病型银屑病是银屑病的一种特殊类型,以全身皮肤弥漫性潮红、浸润肿胀和大量糠状鳞屑为特征,常伴系统性症状,且病情较严重、容易复发。本共识专家组在国内外最新指南及共识的基础上,结合我国的诊疗现状,针对红皮病型银屑病的病因及发病机制、临床表现、辅助检查、诊断、鉴别诊断及治疗等方面进行了详细阐述并形成共识,旨在进一步规范红皮病型银屑病的诊疗模式,以期为我国红皮病型银屑病的诊疗提供更为科学、权威的参考依据。
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Erythrodermic psoriasis is a special type of psoriasis, characterized by diffuse erythema, infiltration, swelling and excessive desquamation throughout the body. It is often accompanied by systemic symptoms, leading to serious disease condition, and it is easy to relapse. Based on the latest Chinese and international guidelines and consensus, and combined with the current status of diagnosis and treatment in China, the expert committee established this consensus that focused on the etiology and pathogenesis, clinical manifestations, auxiliary examination, diagnosis, differential diagnosis and treatment of erythrodermic psoriasis, aiming to further standardize the diagnosis and treatment patterns of erythrodermic psoriasis, and provide a more scientific and authoritative reference for its diagnosis and treatment in China.
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耐药皮肤癣菌感染是近期临床微生物领域与皮肤病领域关注的热点。我国已经出现耐药皮肤癣菌感染病例,预示存在人群传播的风险。中国中西医结合学会皮肤性病学分会真菌学组、中国耐药皮肤癣菌病诊治与防控工作组组织专家基于已有的循证医学证据和研究数据,对耐药皮肤癣菌的病原学、流行病学、菌株鉴定、体外药物敏感性试验以及耐药皮肤癣菌感染的诊断、治疗和防控提出推荐建议,制订了完整的诊治方案,以期为我国耐药皮肤癣菌感染的临床诊治与防控提供科学参考。
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Drug-resistant dermatophyte infections are a hotspot issue in the fields of clinical microbiology and dermatology. Cases of antifungal-resistant dermatophyte infections have emerged in China, predicting a risk of transmission among humans. Based on the existing medical evidence and research data, the Mycology Group of Combination of Traditional and Western Medicine Dermatology and Chinese Antifungal-Resistant Dermatophytosis Expert Consensus Group organized experts to make recommendations and develop the consensus on the pathogenicity, epidemiology, identification, in vitro drug susceptibility test of antifungal resistance dermatophytes, and the diagnosis, treatment, prevention and control of the infections. Further, complete diagnosis and treatment recommendations were made in the consensus, aiming to provide a scientific reference for the clinical diagnosis, treatment, prevention and control of drug-resistant dermatophyte infections in China.
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皮肤结核是由结核分枝杆菌复合群引起的慢性感染性皮肤病,临床表现多样,诊断困难,延误诊断可能导致皮肤与软组织损毁,其诊断需要综合临床、病理、实验室检查等指标综合判断。皮肤结核治疗疗程长且需要多种抗生素联合治疗,早期规范的诊疗是保证良好预后的关键。本共识在参考国内外皮肤结核与结核相关文献、指南基础上编写,旨在规范皮肤结核诊疗流程,提高皮肤结核的治疗效果。
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Cutaneous tuberculosis is a chronic infectious skin disease caused by Mycobacterium tuberculosis complex. It has various clinical manifestations and is difficult to be accurately diagnosed. Delayed diagnosis may lead to serious damage to the skin and soft tissues. The diagnosis of cutaneous tuberculosis requires a comprehensive assessment of clinical, pathological, and laboratory findings. A longcourse combination antibiotic therapy is commonly needed for the treatment of cutaneous tuberculosis, and early standardized diagnosis and treatment are the key to ensuring a good prognosis. This expert consensus was developed based on Chinese and international literature and guidelines on cutaneous tuberculosis and tuberculosis, aiming to standardize the diagnostic procedure and improve the treatment outcomes of cutaneous tuberculosis.
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目的研究皮肤光损伤、变应性接触性皮炎和银屑病这3种常见皮肤炎症损伤模式中角质形成细胞S100A8/A9表达的调控效应差异。方法选取6 ~ 8周龄野生型C57BL/6JGpt小鼠分别进行以下几组实验:①使用单次中波紫外线(UVB)照射小鼠脱毛背部,构建皮肤光损伤模型(UVB组,n = 4),对照组不照射(n = 4);②使用2,4-二硝基氯苯(DNCB)涂抹小鼠右耳构建变应性接触性皮炎模型(DNCB组,n = 4),小鼠左耳涂抹基质对照(对照组,n = 4);③小鼠脱毛背部外用咪喹莫特乳膏构建银屑病样皮炎模型(咪喹莫特组,n = 4),对照组小鼠涂抹凡士林(n = 4)。使用苏木精-伊红(HE)染色检测各组小鼠皮肤样本组织病理变化,免疫组化及Western印迹法检测小鼠背部表皮或耳部皮损中S100A8和S100A9的表达。体外培养的HaCaT细胞分别进行以下几组实验:①UVB组细胞接受单次50 mJ/cm~2 UVB照射,对照组不照射;②采用模拟变应性接触性皮炎中炎症环境的肿瘤坏死因子α(TNF-α)和γ干扰素(IFN-γ)(两者简称为TI)处理HaCaT细胞(TI组),对照组加入相应溶媒处理;③采用模拟银屑病样炎症环境的5种细胞因子[白细胞介素17A(IL-17A)、IL-22、IL-1α、抑瘤素M和TNF-α,简称为M5]处理HaCaT细胞(M5组),对照组加入相应溶媒。采用实时荧光定量PCR、Western印迹法和酶联免疫吸附试验分别测定S100A8和S100A9的转录、表达和胞外分泌水平。结果免疫组化及Western印迹检测显示,在皮肤光损伤、变应性接触性皮炎和银屑病这3种炎症小鼠模型皮损组织中,S100A8、S100A9表达量均明显高于相应的对照组,且免疫组化结果显示,这两种蛋白在银屑病样皮炎模型中增多更为显著。体外细胞实验中,单次UVB、TI和M5分别处理HaCaT细胞12 h后S100A8、S100A9转录水平明显高于相应对照组,处理24 h后亦均高于相应对照组[S100A8、S100A9 mRNA表达水平:UVB组比对照组分别为6.14 ± 0.60比1.00 ± 0.08,2.58 ± 0.06比1.02 ± 0.22,均P < 0.01;TI组比对照组分别为3.90 ± 0.75比1.00 ± 0.02,2.42 ± 0.30比1.01 ± 0.13,均P < 0.05;M5组比对照组分别为157.59 ± 9.30比1.00 ± 0.11,251.37 ± 6.63比1.00 ± 0.03,均P < 0.001];24、48 h,UVB组、TI组和M5组的S100A8/A9分泌蛋白水平均显著高于相应的对照组(均P < 0.001),但其响应模式存在一些差异,在银屑病样皮炎模型中响应更为显著;同时,M5组HaCaT细胞中S100A8、S100A9胞内蛋白表达水平显著高于对照组(t = 4.66、4.63,均P < 0.01),而UVB组和TI组HaCaT细胞中S100A8、S100A9胞内蛋白表达水平低于对照组(UVB组比对照组:t =-3.75、-3.34,P = 0.020、0.029;TI组比对照组:t =-3.30、-4.50,P = 0.030、0.011)。结论角质形成细胞在3种常见皮肤炎症损伤后响应活跃,其效应分子S100A8、S100A9作为机体的损伤相关分子密切参与UVB诱导的皮肤光损伤、变应性接触性皮炎和银屑病中炎症反应,尤其在银屑病样皮炎中响应可能更为显著。
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Objective To investigate different regulatory effects of S100A8/A9 expressed by keratinocytes in 3 common inflammatory skin injury modes: UVB-induced skin injury, allergic contact dermatitis, and psoriasis. Methods Wild-type C57BL/6JGpt mice aged 6 to 8 weeks were selected for the following experiments: (1) mouse models of UVB-induced skin injury were established by single exposure to ultraviolet B (UVB) radiation on the shaved dorsal skin of mice (UVB group, n = 4), with the mice receiving no UVB radiation serving as a control group (n = 4); (2) mouse models of allergic contact dermatitis were established by application of 2,4-dinitrochlorobenzene (DNCB) to the right ears of mice (DNCB group, n = 4), with the left ears of mice treated with a vehicle control serving as a control group (n = 4); (3) mouse models of psoriasis-like skin inflammation were established by topical application of imiquimod cream to the depilated dorsal skin of mice (imiquimod group, n = 4), with the mice treated with vaseline serving as a control group (n = 4). Hematoxylin-eosin (HE) staining was performed to assess histopathological changes in mouse skin tissues obtained from each group, and immunohistochemical study and Western blot analysis were performed to determine the expression of S100A8 and S100A9 in the mouse dorsal epidermis or ear skin lesions. In vitro cultured HaCaT cells were subjected to the following experiments: (1) cells in the UVB group were treated with a single UVB irradiation at a dose of 50 mJ/cm~2, and cells in the control group received no irradiation; (2) some cells were treated with tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) (collectively referred to as TI), and named as the TI group, which simulated the inflammatory environment in allergic contact dermatitis, while cells treated with corresponding solvents served as the control group; (3) cells were treated with 5 cytokines (interleukin 17A [IL-17A], IL-22, IL-1α, oncostatin M, and TNF-α, collectively referred to as M5), and named as the M5 group, which simulated the inflammatory environment in psoriasis, while cells treated with corresponding solvents served as the control group. Real-time fluorescence-based quantitative PCR, Western blot analysis, and enzyme-linked immunosorbent assay were performed to determine the mRNA and protein expression of S100A8 and S100A9, and to detect the extracellular secretion level of S100A8/A9, respectively. Results Immunohistochemical study and Western blot analysis revealed that S100A8 and S100A9 expression levels were significantly higher in the skin lesions of mouse models of UVB-induced skin injury, allergic contact dermatitis, and psoriasis-like skin inflammation than in their corresponding control groups; immunohistochemical study further demonstrated that the increase in the expression of the two proteins was more pronounced in the mouse models of psoriasis-like skin inflammation. In the in vitro cell experiments, the mRNA expression of S100A8 and S100A9 in HaCaT cells at 12 and 24 hours were markedly higher in the UVB group (e.g., at 24 hours, 6.14 ± 0.60 vs. 1.00 ± 0.08, 2.58 ± 0.06 vs. 1.02 ± 0.22, respectively, both P < 0.01), TI group (e.g., at 24 hours, 3.90 ± 0.75 vs. 1.00 ± 0.02, 2.42 ± 0.30 vs. 1.01 ± 0.13, respectively, both P < 0.05), and M5 group (e.g., at 24 hours, 157.59 ± 9.30 vs. 1.00 ± 0.11, 251.37 ± 6.63 vs. 1.00 ± 0.03, both P < 0.001) than in the corresponding control groups, so were the extracellular secretion levels of S100A8/A9 at 24 and 48 hours (all P < 0.001), with some differences observed in their response patterns; notably, the response was more pronounced in the mouse model of psoriasis-like skin inflammation.
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目的了解我国淋病近年流行趋势与时空分布特征,为我国淋病的精准防控提供参考依据。方法通过中国疾病预防控制信息系统传染病监测系统收集2018—2023年全国(不含港澳台地区)各县区淋病病例报告数据,使用Joinpoint回归模型分析我国淋病报告发病率趋势。采用全局空间自相关中的Moran指数、全局G系数与局部空间自相关分析探索淋病在县区层面的聚集模式及热点地区,通过时空扫描分析中的Poisson分布模型识别淋病聚集区。结果2018—2023年我国淋病的报告发病率由9.59/10万下降到7.35/10万,年均变化百分比为-4.9%,发病率下降趋势无统计学意义(P = 0.11)。全国各县区淋病报告发病率呈显著的空间正自相关,Moran指数在0.39 ~ 0.60之间(P<0.001);全局G系数检验统计量Z(G)均>1.96,表明淋病疫情呈现高值聚集模式。局部空间自相关结果显示,热点地区主要分布在我国东南沿海和西南地区。时空扫描共识别出70个聚集区,主要分布在东南沿海和西南地区。结论近6年我国淋病报告发病率总体上呈波动下降;全国淋病在县区层面有显著的时空聚集特点,热点地区和时空聚集区基本一致,主要分布于东南沿海和西南地区,需进一步调查其成因并采取精准的防控措施。
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Objective To investigate the recent epidemic trends and spatiotemporal distribution characteristics of gonorrhea in China, and to provide a reference for precise prevention and control of gonorrhea. Methods Data on reported cases of gonorrhea in China (not including Hongkong, Macau and Taiwan regions of China) were collected from the Infectious Diseases Surveillance System of Chinese Disease Prevention and Control Information System from 2018 to 2023. The trends in reported incidence rates of gonorrhea in China were analyzed using the Joinpoint regression model. Global spatial autocorrelation analysis with the Moran′s index and global G-statistic, as well as local spatial autocorrelation analysis, were employed to explore the clustering patterns and hotspot regions of gonorrhea at the county level. In the spatiotemporal scanning analysis, a Poisson distribution model was employed to identify clusters of gonorrhea cases. Results The reported incidence rates of gonorrhea in China decreased from 9.59 per 100 000 in 2018 to 7.35 per 100 000 in 2023, with an average annual percent change of-4.9%, but this decreasing trend was not statistically significant (P = 0.11). The reported incidence rates of gonorrhea at the county level in China exhibited a significant positive global spatial autocorrelation, with the global Moran′s indices ranging from 0.39 to 0.60 (all P < 0.001); the Getis-Ord general G test statistic Z(G) values were all greater than 1.96, indicating a high-value clustering pattern of gonorrhea cases. The local spatial autocorrelation analysis showed that hotspot regions were predominantly distributed in southeastern coastal areas and southwestern China. A total of 70 clusters were identified through the spatiotemporal scanning analysis, and mainly located in southeastern coastal areas and southwestern China. Conclusions In recent 6 years, the overall reported incidence rates of gonorrhea in China showed a fluctuating decline; there was a significant spatiotemporal clustering characteristic with regard to gonorrhea epidemic at the county level in China, and the hotspot regions were basically consistent with the spatiotemporal clusters, which were mainly distributed in southeastern coastal areas and southwestern China. Further investigation into the causes and precise prevention and control measures are needed.
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目的分析我国近年生殖道沙眼衣原体感染的流行趋势和时空分布特征,为精准防控提供参考。方法通过中国疾病预防控制信息系统传染病监测系统收集2018—2023年全国(不含港澳台地区)生殖道沙眼衣原体感染疫情报告数据,应用Joinpoint 4.9.1软件进行时间趋势分析,使用ArcGIS 10.5软件以县区为地理单位进行全局和局部空间自相关分析,应用SaTScan 10.1.2软件进行时空扫描分析。结果2018—2023年全国生殖道沙眼衣原体感染报告发病率从12.66/10万轻度下降至12.45/10万,年均变化比例为-1.42%,下降趋势无统计学意义(t =-1.14,P = 0.318)。全国县区级生殖道沙眼衣原体感染报告发病率呈显著的全局空间正自相关,全局Moran指数为0.68 ~ 0.74(均P < 0.001);全局G系数标准化统计量Z(G)均 > 1.96,聚集模式为高值聚集。局部空间自相关分析显示,华南和华东部分地区是生殖道沙眼衣原体感染发生的热点地区。时空扫描分析共探测到38个有统计学意义的时空聚集区,主要分布在华南及华东地区,与热点地区一致。结论2018—2023年我国生殖道沙眼衣原体感染报告发病率轻度下降,疫情存在时空聚集特征,需要针对热点地区和时空聚集区开展精准防控工作。
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Objective To investigate the epidemic trends and spatiotemporal distribution characteristics of genital Chlamydia trachomatis infection in China in recent years, and to provide a reference for its precise prevention and control. Methods Data on reported cases of genital Chlamydia trachomatis infection in China (not including Hongkong, Macau and Taiwan regions of China) were collected through the Infectious Diseases Surveillance System of Chinese Disease Prevention and Control Information System from 2018 to 2023. The trend in the incidence rate was analyzed using the Joinpoint 4.9.1 software. Global and local spatial autocorrelation analyses at the county level were conducted using the ArcGIS 10.5 software. Spatiotemporal scanning analysis was carried out with the SaTScan 10.1.2 software. Results The reported incidence rates of genital Chlamydia trachomatis infection slightly declined from 12.66 per 100 000 in 2018 to 12.45 per 100 000 in 2023, with an average annual percent change of -1.42%, which was not statistically significant (t =-1.14, P = 0.318). The reported incidence rates of genital Chlamydia trachomatis infection at the county level in China showed a significant positive global spatial autocorrelation, with the global Moran′s indices ranging from 0.68 to 0.74 (all P < 0.001); the standardized statistic Z (G) values for the Getis-Ord general G were all greater than 1.96, indicating a high-value clustering pattern. Local spatial autocorrelation analysis revealed that hotspot areas were predominantly located in southern and eastern China. In the spatiotemporal scanning analysis, 38 statistically significant spatiotemporal clusters were identified, mainly distributed in southern and eastern China and consistent with the hotspot areas. Conclusions From 2018 to 2023, the reported incidence rates of genital Chlamydia trachomatis infection showed a slight decline, and the epidemic exhibited spatiotemporal clustering characteristics in China. Targeted prevention and control measures need to be implemented in hotspot areas and spatiotemporal clusters.
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目的检测1个显性营养不良型大疱性表皮松解症家系基因突变情况。方法先证者男,20岁,自出生后四肢反复出现水疱、破溃、色素沉着、瘢痕、指(趾)甲变形等。该家系3代共5例患者,均有典型皮损。提取该家系14名成员(包括5例患者)和100名无亲缘关系健康对照的外周血标本,对先证者行全外显子组测序,选定相关的突变位点,在家系中用Sanger测序验证该突变位点。结果基因测序示,先证者及其他4例患者COL7A1基因的第107号外显子均存在错义突变(c.7885G>A),导致第2629位氨基酸由甘氨酸变为精氨酸(p.G2629R),9名健康亲属和100名健康对照未发现该突变。该家系中该突变符合与显性营养不良型大疱性表皮松解症共分离,在Pubmed、HGMD、ClinVar等多种数据库查询未见收录,考虑该突变为新发错义突变,其编码的氨基酸改变Ⅶ型胶原蛋白结构,从而影响蛋白功能。结论在该显性营养不良型大疱性表皮松解症家系COL7A1基因107号外显子发现了新的错义突变,扩展了COL7A1基因突变数据库。
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Objective To detect gene mutations in a pedigree with dominant dystrophic epidermolysis bullosa (DDEB). Methods A 20-year-old male proband presented with repeated blisters, ulceration, pigmentation, scars on the limbs, and deformation of the nails/toenails after birth. There were 5 patients in the 3-generation family, and they all presented with typical skin lesions. Peripheral blood samples were obtained from 14 members of the pedigree (including the 5 patients) and 100 unrelated healthy controls. Whole-exon sequencing was performed on the proband to identify relevant mutation sites, which were then confirmed in the family by Sanger sequencing. Results Genetic testing indicated that the proband and the other 4 patients all carried a missense mutation (c.7885G>A) in exon 107 of the COL7A1 gene, resulting in the substitution of glycine by arginine at amino acid position 2629 (p.G2629R). The mutation was not identified in the 9 healthy relatives or 100 unrelated healthy controls. The mutation co-segregated with DDEB in the family, and was not included in databases such as Pubmed, HGMD or ClinVar, suggesting it was a novel missense mutation. The amino acid encoded by this mutation may alter the structure of type Ⅶ collagen, thereby affecting its function. Conclusion A novel missense mutation was identified in exon 107 of the COL7A1 gene in the family with DDEB, expanding the spectrum of mutations in the COL7A1 gene.
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报道7例以额颞部色素沉着为特征的患儿。7例患儿中,男2例,女5例,发病年龄9 ~ 24(12.43 ± 5.32)个月,病程1 ~ 4(2.57 ± 1.27)个月。皮肤科检查:患儿额颞部散在分布数量不等的咖啡色斑点、斑片,形状不规则,表面未见明显鳞屑。皮肤镜检查:可见多发的假网状黄褐色色素斑片,边界不规则,部分皮损可见线状血管。诊断:儿童面部获得性色素沉着斑。均未予特殊处理,随访2年,2例色素沉着斑完全消退,4例不同程度减轻,1例无变化。结合文献及本文病例推测儿童面部获得性色素沉着斑是一种独立的疾病。
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To report 7 Chinese children with characteristic hyperpigmented macules on the forehead and temples. Among the 7 cases, there were 2 males and 5 females, with the age at onset ranging from 9 to 24 months (12.43 ± 5.32 months), and a disease duration of 1 to 4 months (2.57 ± 1.27 months). Skin examination revealed that the children presented with varying numbers of irregular brown macules and patches scattered on their foreheads and temples, without distinct desquamation. Dermoscopic examination revealed multiple yellowish-brown patches with irregular borders, and linear vessels were observable in some skin lesions. A diagnosis of acquired facial hyperpigmented macules was made in these children.The children received no treatment. After 2 years of follow-up, hyperpigmented macules completely subsided in 2 cases and regressed to varying degrees in 4 cases, while 1 case exhibited no changes in the skin lesions. Considering the literature and the cases discussed in this article, it is hypothesized that acquired facial hyperpigmented macules in young children may represent an independent condition.
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中华医学会和欧莱雅集团在2003—2018年间联合启动了“中国人健康皮肤/毛发研究项目”,该项目在助力提高中国皮肤科医生科研能力的同时,获得了大量宝贵的基于中国人群样本的临床和基础研究成果,并以期刊论文、会议报告等形式多次参与国内和国际学术交流。本文作者通过整理项目资料和已发表文献,对皮肤相关研究项目的主要成果做一总结。
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Chinese Medical Association and L′Oreal Group jointly launched the“ China Skin & Hair Grant” from 2003 to 2018 to support Chinese dermatologists in skin and hair research. This program has not only helped improve the research capability of Chinese dermatologists, but also yielded abundant valuable Chinese population-based clinical and basic research results, and further enabled active academic communication through Chinese and international journals and conferences. This article summarizes main results from skin-related research projects based on program records and publications.
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系统性红斑狼疮是一种累及多个器官系统的复杂的自身免疫性疾病。2023年系统性红斑狼疮的发病机制、诊断和评估、治疗方案等方面取得了一系列重要的研究成果,本文综述主要代表性成果。
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Systemic lupus erythematosus is a classical autoimmune disease that affects multiple organs and systems. In 2023, a lot of new research progress was made in the pathogenesis, diagnosis, evaluation, and treatment of systemic lupus erythematosus. This review summarizes the major representative achievements.
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近年来,肉毒毒素被用于应对许多皮肤疾病和问题。本文回顾和分析肉毒毒素在皮肤科的超适应证临床应用,主要包括面部潮红、雷诺现象、带状疱疹后神经痛、银屑病等,为这些皮肤问题的治疗提供新的手段和思路。
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In recent years, botulinum toxin has been used in many skin diseases and related problems. This review summarizes and analyzes the off-label clinical application of botulinum toxin in dermatology, including facial flushing, Raynaud phenomenon, postherpetic neuralgia, psoriasis, etc., in order to provide new means and ideas for the management of these skin conditions.
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近年来,皮肤瘙痒发病机制的研究有了较大进展,开发了许多新型靶向治疗药物,主要包括针对参与瘙痒信号传导通路如神经激肽受体1、原肌球蛋白相关激酶A、瞬时受体电位香草酸亚型1、瞬时受体电位M8通道、白细胞介素31等的小分子药物或生物制剂。部分药物对多种皮肤病的瘙痒治疗有良好的有效性和安全性,为瘙痒患者尤其是对传统药物治疗抵抗的患者提供了更多选择。本综述总结以上针对瘙痒信号传导通路的小分子及生物制剂药物的研究进展,以期为瘙痒治疗提供更多的方法。
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In recent years, great progress has been made in the research on the pathogenesis of pruritus, and many new targeted therapeutic drugs have been developed, mainly including small-molecule drugs or biological agents targeting signal transduction pathways involved in the pathogenesis of pruritus, such as neurokinin-1 receptor, tropomyosin-related kinase A, transient receptor potential vanilloid 1, transient receptor potential melastatin 8 channels, interleukin 31, etc. Some of these drugs have shown good efficacy and safety in the treatment of pruritus in a variety of skin diseases, providing more options for patients with pruritus, especially those who are resistant to traditional drug treatment. This review summarizes research progress in the above small-molecule drugs and biological agents targeting signaling pathways involved in pruritus, in order to provide more options for pruritus treatment.
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肿瘤坏死因子α(TNF-α)抑制剂(TNFi)已成为慢性炎症性疾病患者无法耐受传统治疗或传统治疗失败时的重要选择。2% ~ 5%使用TNFi的患者会诱发银屑病皮损或加重银屑病,TNFi既是治疗银屑病的药物又是诱因时,被称为矛盾性银屑病。矛盾性银屑病与经典银屑病的临床表现类似,但免疫学机制不同。该文概述了矛盾性银屑病的发病机制、临床病理特点和处置流程,同时总结了其他常见生物制剂使用中出现矛盾性银屑病的概况。
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Tumor necrosis factor (TNF)-α inhibitors have become an important choice for patients with chronic inflammatory diseases who are intolerant or poorly responsive to conventional therapies. Studies have shown that psoriasis can develop or be exacerbated in 2%-5% of patients treated with TNF-α inhibitors, and this phenomenon is called paradoxical psoriasis. Paradoxical psoriasis and classic psoriasis have similar clinical manifestations, but different immunological mechanisms. This review summarizes the pathogenesis, clinicopathological features and management of paradoxical psoriasis, and provides an overview of paradoxical psoriasis following the application of other common biological agents.
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[目的]了解辐照引起的核结构材料的降质过程对于反应堆安全运行至关重要.然而,由于辐照损伤实验和基于物理的多尺度模拟存在时间和资源密集性的特点,无法快速评估材料的空洞演化行为.[方法]应用卷积神经网络(CNN)对空洞尺寸和数密度进行预测,并在现有的实验数据范围外,对氦和氢注入量在连续参数变化范围内的相关性进行预测.[结果]经过参数优化的CNN可以很好地克服实验数据不足的限制,仅利用元素组分和环境参数即获得准确的数值回归.[结论]这项工作证明了CNN预测氢氦协同效应下辐照损伤的可行性,对核材料的优化和反应堆安全运行具有实际意义.
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[Objective] The hydrogen-helium synergistic effect can further enhance irradiation damage and exacerbate the irradiation-induced degradation of the physical and mechanical properties of structural materials.However,due to the time- and resource-intensive property of both experiments and multi-scale simulations in irradiation damage,the trial-and-error approach is entirely inefficient.It is therefore important to explore new methods to accelerate the development of potentially irradiation-resistant materials.In this paper,void size and number density models based on convolutional neural networks (CNN) have been developed to systematically predict the correlation of irradiation parameters across a range of parameter variations. [Methods] Deep learning techniques such as adaptive moment estimation (Adam),dropout layers,and batch normalization,are applied to improve the generalization ability of the prediction models.The model performance is further optimized in three aspects:activation function,number of convolutional layers,and dropout layer values.Finally,the prediction of void size and number density is carried out within a continuous parameter variation range. [Results] Compared with the Sigmoid and Tanh activation functions,the error reduction of the Relu is smoother and exhibits higher computational efficiency.When the number of convolution layers is 3 and the dropout layer value is 0.2,the models achieve the best performance under three evaluation indicators:root mean square error,coefficient of determination (R~2),and mean absolute error.The R~2 of the size prediction model is 92.40% and 88.80% for the training set and testing set,respectively,indicating the absence of underfitting or overfitting problems.Although there is a slightly poor fitting effect on the testing set between the predicted results of the number density prediction model and the measured values,indicating an overfitting problem that needed to be solved,the overall prediction results are relatively consistent with the measured values.The predicted results show that,the void size and number density increase with increasing irradiation damage,suggesting a linear dependence.The void size is small and the number density is large under double-beams irradiation (heavy ions+He~+),while the co-injection of He and H under triple-beams irradiation (heavy+He~++H~+) strongly promotes the void growth.Meanwhile,there is a peak in void size with increasing temperature,and the growth of the void is the result of a sharp decrease in number density.Finally,there is a critical value between the He and H atom injection rates and the void size and number density,suggesting that the evolution of the void under the synergistic effects is controlled by a combination of different He and H atom injection rates. [Conclusions] In conclusion,CNN,as an alternative method,can predict void evolutions without involving physical processes and corresponding physics-based modeling techniques.There are significant synergistic effects between helium,hydrogen,and displacement damage,contributing to void growth rather than nucleate.Therefore,the most crucial aspect in the development of anti-swelling materials is to suppress the growth of voids.In addition,the predicted results can offer inspiration and reference for the design and optimization of high-performance irradiation-resistant materials.For example,the maximum or minimum He and H atom injection rates do not induce the maximum void size,and material degradation may be mitigated by optimizing irradiation parameters.The performance prediction of such systems is difficult to accomplish with experimental methods,but it holds important implications for material design and performance assessment.
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[目的]直接利用模糊C均值(FCM)对原始数据进行聚类,容易导致聚类结果受到噪声和离群点的影响,但通常利用松弛技术对样本点模糊隶属度或空间位置关系进行松弛的解决方法只能降低,而无法完全剔除噪声和离群点的影响.为了解决这个问题,提出了基于截断技术的鲁棒模糊C均值(TRFCM)聚类算法.[方法]基于模糊局部信息C均值(FLICM)聚类模型,通过引入截断技术,提出TRFCM算法.该算法的主要思路为:(1)利用FLICM,在学习数据聚类结构的同时保留样本点的局部邻域结构;(2)基于FLICM的聚类结果动态调整原始数据,使其满足期望的聚类结构;(3)将聚类结构特征学习与原始数据的调整(即截断掉部分样本点),统一在一个优化框架中,从而实现组合最优化.将TRFCM算法与近年来相关算法进行比较以检验TRFCM的参数敏感性、收敛性、鲁棒性、时效性等性能.[结果]实验包括5个部分:参数敏感性与收敛性分析、鲁棒性检验、图像分割实验、Benchmark数据集实验和各算法计算时间对比实验.在参数敏感性和收敛性分析中,TRFCM算法在合适的范围内对参数不敏感且在大多数情况下可以获得良好的聚类效果.同时,算法对各数据集的聚类均可以在20轮迭代内收敛.在鲁棒性检验中,TRFCM的准确率是81.55%,较FLICM高出9.71个百分点,聚类结果更接近于真实数据分布,这证明了TRFCM对噪声具有良好的鲁棒性.在图像分割实验中,各对比算法对图像的划分在一定程度上都不够准确,部分算法出现了环境划分不完整、不同的部分错分到相同类中、不同的类之间发生重叠等问题.而TRFCM均规避了这些问题,取得了良好的聚类结果.在添加了均值为0、方差为0.05的高斯噪声的图像分割实验中,TRFCM算法对噪声干扰的抑制效果最优.在Benchmark数据集上,对Banknote Authentication、Wine、COIL20、WarpPIE10P、Yale和USPS数据集进行聚类分析,TRFCM在ACC、NMI与purity三种评价指标上都取得了优于其它对比算法的得分.在算法时效性的实验中,在相近的时间内,相较对比算法TRFCM能够获得更好的聚类效果.[结论]将截断技术引入到模糊聚类算法中,可实现对原始数据的动态调整,剔除噪声和离群点对聚类过程的干扰,从而保留更多对聚类有利的数据细节.基于该思路,利用截断技术以相似的方式对以往其他经典的模糊聚类模型进行改进,可以得到一系列的优化算法,为未来的研究提供新的方向.
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[Objective] Fuzzy C-means (FCM) performs the clustering directly on original data,and is sensibly influenced by noises and outliers.Currently for the purpose of tackling this issue,the most widely used method is based on mining results of data clustering structure and relaxing the fuzzy membership or local relationship of the sample points.Nevertheless,it can only reduce,but not completely eliminate,the effect of noises and outliers.To address this issue,herein we propose a novel clustering algorithm called truncated robust fuzzy C-means (TRFCM). [Methods] In TRFCM,the truncation technique is introduced based on the fuzzy local information C-mean (FLICM) model.The main idea of the proposed TRFCM is threefold: (1) by utilizing FLICM,the local neighborhood structure of sample points is preserved during the learning of data clustering structure; (2) on the basis of the clustering result of FLICM,original data is adjusted dynamically to meet the desired clustering structure; (3) an optimization framework is constructed to appropriately integrate (1) and (2). [Results] Proposed TRFCM is compared with algorithms developed in recent years.Our comparative experiments include categories,namely (1) parameter sensitivity and convergence analysis,(2) robustness,(3) image segmentation,(4) benchmark dataset and (5) computational time cost.For (1),within the appropriate range,TRFCM behaves insensitively to the parameter and can produce effective clustering results in most cases.Meanwhile,the clustering algorithm on each dataset can converge within 20 rounds of iterations.For (2),the accuracy of TRFCM reaches 81.55%,exceeding FLICM by 9.71 percentage points and clustering results approach closely to the real data distribution,demonstrating the robustness of TRFCM to noises.In (3),all compared algorithms do not behave sufficiently accurately to segmenting the image to a certain extent,and some of them endure troubles such as incomplete segmentation of environment,misclassification of different parts into the same class,and overlap among different classes.Instead,TRFCM avoids all these problems and produces satisfactory clustering results.To further compare the robustness of each algorithm to noises,we perform the image segmentation on images added with Gaussian noises with mean 0 and variance 0.05.Experimental results show that TRFCM performs optimally for the suppression of noise interferences.In (4),the clustering analysis is applied on Banknote Authentication,Wine,COIL20,WarpPIE10P,Yale and USPS datasets.During the experiment,10 repetitions of random initialization are conducted to measure the mean and standard deviation of three clustering metrics: ACC,NMI,and purity.According to experimental results,TRFCM achieves more satisfactory clustering results than other comparative algorithms do in those three aforementioned evaluation metrics.This outcome suggests that,in addition to the application of image segmentation,TRFCM also performs effectively for the division of real-world discrete datasets.In (5),TRFCM achieves more satisfactory clustering results compared to other algorithms under similar time costs. [Conclusions] A fuzzy clustering algorithm called TRFCM is proposed.Based on FLICM,the truncation technique is introduced to enable the improved TRFCM to dynamically adapt to original data and remove the interference of noises and outliers during clustering,so that more useful details for clustering are retained.TRFCM achieves meritorious results in the parameter sensitivity and convergence analysis,robustness testing,image segmentation experiments,benchmark dataset experiment as well as computational time-cost experiment,indicating the effectiveness of the algorithm.Inspired by these merits,previous classical fuzzy clustering models can be similarly modified by the truncation technique as an essential future research direction.
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[目的]针对健康肉与病害肉的快速鉴别问题,本文对健康与病害肉的表面拉曼谱图的特征信息提取和分类方法进行研究,以实现对健康肉与病害肉的快速鉴别.[方法]以羊肉的表面增强拉曼谱图为样本,分别采用主成分分析-支持向量机和卷积神经网络两种方法进行分类.通过提取谱图的精细化特征,实现谱图数据的降维和干扰信息的过滤,为分类模型提供更加准确和丰富的特征信息.并以240份包含健康与病害羊肉的拉曼谱图为训练集样本,建立了分类模型,以另外的120份样本进行健康与病害肉的辨别效果验证.[结果]实验表明经过精细化特征提取后构建的主成分分析-支持向量机模型能清晰的找到健康与病害肉的分类边界,验证样本的识别准确率从82.5%上升到93.3%,同时使用卷积神经网络对精细化提取的特征进行学习与分类,识别准确率从常规方法的90.2%上升到95.5%.[结论]本文提出的基于表面增强拉曼的肉类谱图的精细化特征信息提取和分类方法能够有效实现对羊肉样品中健康肉与病害肉的快速分类和鉴别,该方法同样可以应用于其他肉类的检测分类,对保障食品安全具有重要的意义.
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[Objective] Aiming at the rapid identification of healthy and diseased meat,herein we investigate the information extraction and classification methods of the surface Raman spectra of healthy and diseased meat. [Methods] Taking the surface-enhanced Raman spectrogram of mutton as a sample,we use two methods,principal component analysis-support vector machine and convolutional neural network for classification,respectively.Through the refined feature extraction of the spectrogram,the filtering of the spectrogram degradation and interference information is accomplished,thus providing more accurate and rich feature information for the classification model. In the experimental validation,240 Raman spectra containing healthy and diseased mutton were used as the training set samples to build the classification model,and other 120 samples were used to validate the identification effect between healthy and diseased meat. [Results] Experiments show that the principal component analysis-support vector machine model constructed after refined feature extraction can clearly find the classification boundary between healthy and diseased meat,and the recognition accuracy of the validation samples rises from 82.5% to 93.3%.At the same time,if the convolutional neural network that learns and classifies refined extracted features is used,the recognition accuracy rises from 90.2%,achieved by the conventional method,to 95.5%. [Conclusions] The refined feature information extraction and classification method of meat spectra based on surface-enhanced Raman proposed herein can effectively achieve the rapid classification and identification of healthy and diseased meat in mutton samples.Additionally,it can be applied to the detection and classification of other meats,and this application leads to great potential in guaranteeing food safety.
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[目的]利用无人机进行大尺度非结构地形环境测绘时,由于无人机倾斜摄影得到的图像在测绘建模时会存在仿射变形较大、透视畸变严重、局部特征变化各异等问题,进而导致建模数据匹配困难.为解决这一问题,本文提出了一种基于特征融合的倾斜摄影测绘建模优化方法.[方法]首先融合图像的颜色信息及近似最近邻快速库(fast library for approximate nearest neighbors,FLANN)优化的加速稳健特征(speed up robust feature,SURF),然后结合优化的SURF与最稳定颜色区域特征(maximally stable color regions,MSCR)实现仿射变形图像间快速准确的特征提取及匹配.[结果]本文的特征匹配算法在1.25 s内得到757个最佳匹配点;相对于基于尺度不变特征(scale-invariant feature transform, SIFT)、SIFT+MSCR和SURF的特征匹配算法,最佳匹配点的数量分别提高141%、29%和34%,匹配时间与SURF接近,远低于SIFT和SIFT+MSCR.测绘建模得到的点云与参考点在三个方向上的距离均方根误差在7 cm以内,平均误差在11 cm以内.[结论]本文提出的算法能够实现非结构地形环境的全局三维模型快速准确构建,同时数据匹配过程中具有更良好的匹配效果和匹配效率.
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[Objective] For years,data-matching difficulties caused by large affine deformation,severe perspective distortion,and varying local feature changes among unmanned aerial vehicle oblique photography images amid large-scale unstructured terrain environments have existed.Herein,to overcome these difficulties,we propose a feature-fusion optimization method for oblique photography modeling based on unmanned aerial vehicle oblique photography technology. [Methods] First,in the proposed algorithm,we integrate the color information of the image and the fast library for approximate nearest neighbors (FLANN) algorithm to optimize and accelerate the robust feature (SURF).Then,combining optimized SURF features with maximally stable color regions (MSCR) features,we have achieved fast and accurate feature extraction and matching among affine deformed images can be achieved.Finally,the global 3D model of unstructured terrain environments is quickly and accurately constructed. [Results] The comprehensive comparative analysis shows that the feature-matching algorithm integrates advantages of SURF point features and MSCR region feature algorithms.Notably,we obtain 757 best matching points within 1.25 s and achieve more accurate matching results. Compared to scale-invariant feature transform (SIFT),SIFT+MSCR,and SURF,the number of optimal matching points obtained by our algorithm is increased by 141%,29%,and 34%,respectively.The matching time of our algorithm is close to SURF and much lower than SIFT and SIFT+MSCR. Meanwhile,traditional algorithms endure data loss due to matching failures,resulting in a large number of point cloud voids in the unstructured terrain environment point cloud constructed by those algorithms.The point cloud collected from the global terrain point cloud of the unstructured environment constructed by the optimization algorithm herein can comprehensively reconstruct the unstructured terrain environment.The average mean error of the constructed unstructured terrain environment point cloud map in three directions of the coordinate axis is reduced to 9.82 cm with the average root-mean-square error of 6.36 cm. [Conclusions] The global unstructured environment 3D terrain model can provide reliable prior information for unmanned vehicles driven in unstructured terrain environments.This paper focuses on the practical challenges faced in the construction process of unstructured terrain environments.By using drone oblique photography technology and combining optimized SURF and MSCR algorithms,fast and accurate feature detection and image matching have been achieved.Finally,the construction of a three-dimensional global unstructured terrain environment point cloud is achieved.Experimental results show that the proposed algorithm can maintain matching robustness,timeliness,and accuracy even under conditions of large affine deformation,severe perspective distortion,and diverse local feature changes in unstructured terrain environments.The proposed algorithm functions satisfactorily for oblique photography modeling in unstructured terrain environments,and ultimately achieves the construction of centimeter level 3D global unstructured terrain environment point cloud maps.
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[目的]由于经济、金融、环境和生态等多个领域中时间序列数据规模的持续增长,对其进行预测变得日益复杂,为了提高大规模时间序列的长期预测效率,探索构建模糊信息粒的创新方法,以准确反映数据集大小和趋势信息.[方法]首先,根据模糊拓展原理,研究各种模糊信息粒,包括区间型、三角型和高斯型模糊信息粒的距离定义.随后,结合时间序列片段的中心线段和离散程度信息,引入一类新颖的模糊信息粒.这些粒子可以有效捕捉指定时间范围内时间序列的趋势信息和离散程度,进一步地提出高斯型模糊信息粒距离的函数表达式和几何解释.为了将这些粒子用于时间序列预测,设计一类模糊推理预测系统,该系统可以利用历史数据构造模糊信息粒,并从高斯型模糊信息粒序列中提取模糊推理规则.[结果]高斯型模糊信息粒距离的函数表达式具有简洁的数学表示,可以合理地反映两个高斯模糊信息粒的中心线和离散程度的差异.模糊推理预测系统可以从高斯型模糊信息粒序列中提取有效的规则,实现时间序列的长期预测.实验结果表明,结合线性高斯模糊信息粒与模糊推理系统的预测方法在均方根误差和平均绝对百分比误差方面优于其他数值预测算法和其他模糊信息粒推理方法,包括自回归模型、自回归神经网络和回归向量机等.[结论]结合线性模糊信息粒和模糊推理系统的方法可以提高时间序列长期预测的效率.基于对数据集特征的合理抽象提出了一种新颖的线性模糊信息粒,并简洁地推导出了它们的距离定义.时间序列预测的成功表明,通过巧妙地设计信息粒,能够准确捕捉数据集中的关键特征,从而提高其他数据挖掘任务的效率,例如更快的计算速度和更准确的结果.
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[Objective] Our research aims to tackle the prevalent challenge of time series prediction in diverse fields such as economics,finance,environment,and ecology.With the continuous growth in the scale of time series data due to advancements in computer and IoT technologies,predicting these large-scale sequences has become increasingly complex.Primarily,we attempt to explore innovative approaches for constructing fuzzy information granules that accurately reflect both dataset size and trend information.In this study,we provide a robust solution to inherent difficulties in forecasting large-scale time series by enhancing the efficiency of prediction algorithms through the strategic design of these granules. [Methods] The research employs a multi-faceted methodology.Initially,the study establishes comprehensive distance definitions for various fuzzy information granules,including interval,triangular,and Gaussian types,based on the fuzzy extension principles.Subsequently,a novel class of fuzzy information granules is introduced,and the central line segment and dispersion of the dataset are considered.These granules effectively capture the development trends and dispersion characteristics of time series within a specified timeframe.In the study,we further present a functional expression and geometric interpretation for the distance of Gaussian fuzzy information granules.To operationalize these granules for time series prediction,we design a fuzzy inference prediction system,and leverage historical data as well as rules extracted from Gaussian fuzzy information granule distances. [Results] The functional expression for Gaussian fuzzy information granule distance constitutes a concise mathematical representation,allowing for a reasonable interpretation as the amalgamation of disparities in central lines and deviation degrees.Then,the fuzzy inference prediction system,in which Gaussian fuzzy information granule distances is utilized,successfully extracts effective rules from extensive historical data,facilitating long-term predictions for time series.Results emphasize the superiority of the proposed approach in terms of root- mean-square error and mean-absolute-percentage error,thus highlighting its potential for improving the accuracy of long-term time series predictions.Comparative analyses against various numerical prediction algorithms and alternative fuzzy information granule inference methods,including autoregressive models,autoregressive neural networks,and regression vector machines,consistently demonstrate enhanced outcomes achieved by combining linear Gaussian fuzzy information granules with the fuzzy inference system. [Conclusions] Our study provides a comprehensive exploration of challenges inherent in time series prediction and proposes a methodology to address these challenges effectively.The designed fuzzy information granules,informed by meticulous distance definitions and consideration of dataset characteristics,offer results for accurate and efficient long-term time series predictions.Satisfactory results in time series prediction suggest that,by skillfully designing information granules,we can accurately capture key features in the dataset,thereby enhancing the efficiency of other data mining tasks.This outcome includes improvements such as fast computational speed and accurate results.
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[目的]对于一些覆盖面广、延续时间长的事件(如台风、洪水等自然灾害),考虑事件演化过程复杂多变,所获取的事件信息存在疏密程度不均的问题,研究其事件推理问题.[方法]提出一种基于注意力机制和图网络的多粒度脚本事件推理方法,通过提取及合并不同粒度的事件信息以获得更丰富的事件语义信息,并结合图注意力网络和事件转移概率矩阵以充分利用密集事件连接提升推理性能.具体而言,首先采用自注意力机制从事件链中获得事件片段,并结合单个事件和事件片段的表示扩展模型输入信息,然后充分利用密集的事件连接,从海量事件新闻中提取事件链构建事件演化图来获得事件转移矩阵,提高模型推理准确率.[结果]在多个真实台风事件以及标准数据集上的实验结果表明,本文所提方法优于传统的基于事件链、基于事件对以及基于事件图等的事件推理模型.[结论]采用自注意力机制从事件链中获得事件片段,并结合单个事件和事件片段的表示扩展模型输入信息可以缓解事件稀疏带来的推理困难问题;仅采用时序关系不能完全表示基本事件链与候选事件的关系,构建事件演化图可以更好的提取事件间的复杂交互信息;多粒度事件信息的融合可以更好地反映候选事件与基本事件链的关系.
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[Objective] When given an existing event context,script event prediction (SEP) aims to predict the subsequent counterpart.However,some disaster events,such as typhoons and floods,due to the complex event evolution process,their event contexts endure different degrees of information density,prompting the event reasoning very challenging.In this paper,we propose a multi-granularity SEP method based on attention mechanism and graph network to solve two problems in complex event reasoning,namely,how to merge different levels of event information to obtain deeper semantic information,and how to fully utilize dense event connections to improve the reasoning ability of the model. [Methods] First,we utilize the dependent syntax and semantic role labeling capabilities of the Language Technology Platform to extract event triples from News texts and construct event chains.Next,we employ the self-attention mechanism to obtain event fragments and merge them with the representations of individual events as inputs to the model.In addition,event chains are extracted from large-scale News texts to construct event evolution graphs and obtain transfer probability matrices between events.Based on these event representations and probability matrices,we construct a three-layer graph attention network (GAT) for inference. [Results] The performance of our proposed method is compared with other eight baseline methods on the benchmark dataset New York Times (NYT).To verify the effectiveness of the proposed method on the disaster events,we also construct a real dataset,which contains 20 typhoons and more than 2 800 related News reports.Overall experimental results on the typhoon dataset and benchmark dataset show that the accuracy of the proposed method reaches as high as 88.2% on the typhoon dataset and 54.23% on the NYT dataset,more satisfactory than other statistical and neural network-based methods.Specifically,on typhoon dataset EventComp,PairLSTM,and LSTM models,in which only strong temporal relationships in the event chain are considered,accuracies of 79.32%,78.45%,and 73.46% are obtained,respectively.On NYT,accuracy of 49.57%,50.83%,and 45.53% are obtained,respectively.The graph-based model SGNN performs more satisfactorily on both the typhoon dataset (87.27%) and the NYT dataset (52.45%) than those event-pair-based models do.Moreover,to investigate the intrinsic mechanisms of how the model improves event prediction performance,we conduct a series of ablation experiments on the typhoon dataset.Experimental results show that removing the event fragment representation leads to a significant performance degradation of 2.6 percentage points,thus highlighting the importance of event fragment representation in the model.Similarly,removing the attention mechanism in the event inference layer triggers a 0.4 percentage point performance degradation,likewise demonstrating the critical role of the attention mechanism in extracting valid information. [Conclusions] The proposed multi-granularity event inference method based on the attention mechanism and graph network attains significant improvements compared with those existing methods.Extracting and combining event information at different granularities,we can obtain richer event semantic information.Also,combining graph attention networks and event transition probability matrices,we can fully utilize dense event connections to enhance inference performance.The experimental analysis shows that the event fragment representation and graph-based learning method constitute the two major factors for enhancing prediction performance.The former shows that the event chain contains key correlation information among events,whereas the latter shows the event evolution graph can extract more effective interaction information among events and the event inference task can perform more satisfactorily.
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[目的]现有的多分辨率层次社区发现方法需要搜索分辨率参数得到特定层次的社区划分,且无法利用网络拓扑与节点属性之间的关联获取社区结构信息.为解决这些限制,本文提出一种基于图增强和图神经网络的层次社区发现方法HCEG.[方法]首先在图增强过程中对原始网络进行重构,使得构建的初始社区种子能涵括节点属性和拓扑信息,然后对初始种子社区集进行合并,再采用基于图神经网络的方法进行拓展,以搜寻网络中不同层次的社区划分.[结果]与其他SOTA方法相比,所提出的HCEG方法可以准确地找到不同类型真实网络中的分层社区结构,并可在不同规模的真实网络中可以获得良好的社区发现性能.[结论]在社交网络、引文网络、网页超链接网络等真实数据集上的一系列实验,验证了HCEG方法的可行性和有效性.
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[Objective] As an effective way to analyze structures and characteristics of a complex network,community detection helps people understand properties and evolution of networks.However,communities in complex networks often contain hierarchical structures,and most existing multi-resolution community detection methods need to search for appropriate resolution parameters to obtain hierarchical community divisions and cannot analyze the association between network topology and node attributes to obtain deep-level community structure information.To address these limitations,we have developed a community detection method that can leverage richer network information while achieving specific accuracy in hierarchical community segmentation. [Methods] In this paper,we propose a hierarchical community detection method (HCEG),based on enhanced graph and Graph Neural Networks (GNN).Specifically,HCEG first utilizes a variational graph autoencoder to reconstruct the network,enabling the link structure of the reconstructed graph to reflect both the topology structure and node information of the original network.Then,by searching for the largest k-plex subgraph in the reconstructed graph,the initial community center is constructed,and features in the attribute network are incorporated into the community generation and graph learning process.Finally,based on the attribute similarity of community members,candidate seed communities are merged and divided into different levels of communities through a GNN model. [Results] Several experiments are conducted to validate the feasibility and effectiveness of the HCEG in hierarchical community detection tasks on multiple attribute networks including user relationship network,scientific publication network,and webpage hyperlink network.Overall experimental results show that the proposed HCEG method can accurately find hierarchical community structures in different types of real networks when compared to other SOTA methods,and HCEG can achieve good community discovery performance in real networks of different sizes.We further investigate the impact of graph enhancement strategies on the community detection performance of the HCEG by varying the proportion of edge augmentation and the type of graph autoencoder.Additionally,we study whether or not graph enhancement strategies should be used.Experimental results on different datasets and levels show that the performance of the HCEG (OG) model (without graph enhancement strategies) is significantly inferior to those of other models,indicating that graph enhancement strategies can effectively improve the performance of the HCEG in community detection tasks.In the process of community expansion,the HCEG method uses an improved GraphSAGE algorithm to match suitable seed communities for the remaining node members in the network.To study the effectiveness of the improved GraphSAGE algorithm in community expansion,we set up a multilayer perceptron (MLP) as a community expansion strategy and compared it with the GraphSAGE.Experimental results show that the HCEG (VGAE+GS) model using the improved GraphSAGE algorithm as a community expansion strategy outperforms the HCEG (VGAE+MLP) model.For the identification of the community categories of nodes in the network,it is not conducive to use only the multilayer perceptron and discard the network topology information. [Conclusions] In this paper,we propose a method for hierarchical community detection based on graph enhancement and graph neural networks,called HCEG.It addresses problems of existing hierarchical community detection methods that cannot efficiently obtain community structures at specific levels and nor can readily leverage attribute network information.
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[目的]研究无监督词性标注模型在低资源语言上的性能表现.[方法]尝试利用无监督词性标注模型,包括高斯隐马尔科夫模型(Gaussian HMM,GHMM)、最大化互信息模型(mutual information maximization,MIM)与条件随机场自编码器(conditional random filed autoencoder,CRF-AE),展开低资源词性标注实验.基于对前人工作的凝练,在英文宾州树库上设置了少样本和词典标注两种低资源场景.[结果]无监督词性标注模型能够在少样本场景中超越条件随机场模型,但在词典标注场景中却始终逊色于条件随机场模型.[结论]无监督损失更加擅长对高频词进行建模,使得模型在少样本场景下获得更好的性能表现;同时无监督损失倾向于生成更加均匀的词性分布,从而降低模型在词典标注场景下的性能.
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[Objective] Part-of-speech (POS) tagging aims to grammatically categorize each word in a sentence with a corresponding POS tag.While the performance of POS tagging models in rich-resource scenarios has indeed advanced,the room for improvements remains in low-resource scenarios,including the few-sample scenario and the dictionary-labeling scenario.Previous research primarily focused on enhancing models from the perspective of training data,with limited attention paid to the model itself.In this paper,we tackle this issue from the perspective of the model and attempt to leverage the unsupervised model so that unlabeled data can be learned. [Methods] Based on the work of predecessors,we set up few-sample scenario and dictionary-labeling scenario.Then,we selected several representative unsupervised POS tagging models,which included Gaussian hidden Markov models (GHMM),mutual information maximization (MIM),and conditional random field autoencoder (CRF-AE).Modifying the training objective functions of these models,we adapted them to those two low-resource scenarios set up by us.Additionally,we chose the traditional supervised POS tagging model,namely conditional random fields (CRF),as the baseline model for comparison. [Results] We conduct experiments on the Penn Tree Bank dataset,which is widely used for unsupervised POS tagging.In the few-sample scenario,MIM achieves the highest performance under the minimal sample size setting,and CRF-AE consistently outperforms CRF when pre-training language models are not employed.However,as the sample size increases,the performance advantage of CRF-AE over CRF diminishes,and the performance of GHMM and MIM also gradually declines in comparison to CRF.After applying the pre-trained language models to both CRF-AE and CRF,significant improvements in model performance are observed,but CRF-AE continues to outperform the CRF model in scenarios with limited and minimal samples.In the dictionary-labeling scenario,CRF consistently achieves the best results across all settings.In contrast,the performance of unsupervised POS tagging models consistently remains inferior.After incorporating pre-trained language models,the performance of CRF has significantly improved.However,the performance of CRF-AE remains substantially more inferior to that of CRF does.Overall,we observe that,in the few-sample scenario,the unsupervised model CRF-AE exhibits superior performance.However,in the dictionary-labeling scenario,the supervised model CRF consistently outperforms the unsupervised model by a significant margin.Furthermore,we analyze the performances of models based on the word frequency distribution predicted by the model.In the few-sample scenario,unsupervised POS tagging models outperform CRF for mid-frequency and high-frequency words,especially for extremely scarce training samples.However,in the dictionary-labeling scenario,although MIM achieves a slightly higher accuracy than CRF for mid-frequency and high-frequency words under the minimal dictionary setting,those unsupervised POS models do not demonstrate an advantage in modeling high-frequency words.To further investigate this phenomenon,we examine the predicted POS distribution of models.It is observed that the predicted POS distribution of unsupervised model deviates more from manual annotations and exhibits a flatter slope overall.Notably,the POS distribution of GHMM and CRF-AE even appears as a horizontal line,suggesting a near-uniform distribution that corresponds to poor performance. [Conclusions] In those two scenarios set herein,unsupervised POS tagging models secure distinct performance characteristics.Unsupervised models can surpass the CRF in the few-sample scenario,but in the dictionary-labeling scenario,the CRF significantly outperforms those unsupervised models.
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[目的]由于购买商品的消费者数量远小于未购买商品的消费者数量,网购意愿预测研究是典型的不平衡数据分类问题.研究不平衡数据的分类问题以提升网购意愿预测的分类准确率,该问题主要存在少数类样本识别准确率远小于多数类样本的问题.[方法]提出一种基于贝叶斯优化的代价敏感轻量梯度提升机(Light Gradient Boosting Machine,LightGBM)模型.首先引入误分类代价作为惩罚因子修正LightGBM的损失函数,其次通过阈值移动降低模型的分类阈值以提高针对少数类样本的预测准确率,最后利用贝叶斯优化算法优化误分类代价参数、分类阈值及其他参数.[结果]从KEEL数据库中选取5个典型的不平衡数据集进行对比实验,相较于标准LightGBM模型,改进LightGBM模型的AUC值和G-mean值均提升了10%左右;相较于遗传算法优化代价敏感LightGBM模型和粒子群优化代价敏感LightGBM模型,改进LightGBM模型的AUC值和G-mean值普遍提升了4%左右;相较于ADASYN-LightGBM模型和BorderlineSMOTE-LightGBM模型,改进LightGBM模型的AUC值和G-mean值普遍提升了3%左右.[结论]基于代价敏感学习在LightGBM损失函数中添加误分类代价作为惩罚因子,并通过阈值移动降低模型的分类阈值,同时利用贝叶斯优化算法优化代价敏感LightGBM模型中的误分类代价参数、分类阈值及其他参数,实现更高的少数类样本预测准确率,提升了网购意愿预测的分类准确率.
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[Objective] The research of online shopping intention prediction is a typical unbalanced data classification problem.The number of consumers buying goods is much smaller than the number of consumers not buying goods.The purpose of this paper is to solve the problem that the recognition accuracy of minority samples is much lower than that of majority samples. [Methods] This paper proposes a cost-sensitive LightGBM (light gradient boosting machine) model based on Bayes optimization.Firstly,the misclassification cost is introduced as a penalty factor to modify the loss function of LightGBM.Secondly,the classification threshold of the model is reduced by threshold shifting to improve the prediction accuracy of minority samples.Finally,the parameters of misclassification cost,classification threshold and other parameters are optimized by Bayes optimization algorithm. [Results] Five typical unbalanced datasets are selected from the KEEL database.To verify the effectiveness of the improved LightGBM algorithm proposed in this paper,the improved LightGBM algorithm is compared with standard LightGBM algorithm,genetic algorithm optimization cost-sensitive LightGBM algorithm,particle swarm optimization cost-sensitive LightGBM algorithm,ADASYN-LightGBM (adaptive synthetic sampling approach) algorithm,BorderlineSMOTE-LightGBM(borderline synthetic minority oversampling technique) algorithm,respectively.The AUC (area under curve) and G-mean (geometric mean) are used as evaluation indexes to evaluate the performance of the model,and the final experimental results are obtained after 100 iterations and cross-validation with ten folds.Compared with the standard LightGBM model,the AUC value and G-mean value of the cost-sensitive LightGBM model have both increased by about 10%,indicating that the introduction of cost-sensitive learning has significantly improved the classification performance of LightGBM model,and can better deal with unbalanced data classification problems.Compared with genetic algorithm optimization cost-sensitive LightGBM model and particle swarm optimization cost-sensitive LightGBM model,the AUC value and G-mean value of Bayes optimization cost-sensitive LightGBM model are generally increased by about 4%.It shows that Bayes optimization has certain advantages in parameter optimization of cost-sensitive LightGBM algorithm.Compared with ADASYN-LightGBM model and BorderlineSMOTE-LightGBM model,the AUC value and G-mean value of Bayes optimization cost-sensitive LightGBM model are generally increased by about 3%.The results show that Bayes optimization cost-sensitive LightGBM model is better than the combination of two sample sampling methods and LightGBM model in the classification of unbalanced data.To verify the validity of the prediction model of consumers' online shopping intention based on Bayes optimization cost-sensitive LightGBM,the paper selects the consumer behavior data provided by Jingdong platform.The data is the historical interaction behavior records of consumers,commodities,categories and stores provided in Jingdong JDATA algorithm competition from February 1,2018 to April 15,2018.The final experimental results are G-mean value of 0.913,AUC value of 0.920 and F_1 value of 0.692.Compared with the prediction results of the other two studies on the same dataset,the prediction model of online shopping intention based on Bayes optimization cost-sensitive LightGBM has better performance. [Conclusions] Aiming at the problem of unbalanced data in online shopping intention research,the paper proposes a prediction model of online shopping intention based on Bayes optimization cost-sensitive LightGBM.Based on cost-sensitive learning,the classification error cost is added to LightGBM loss function as a penalty factor,and the classification threshold of the model is reduced by moving the threshold to improve the prediction accuracy for minority samples.
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[目的]为了适应柔性压力传感器面向特定应用的定制化设计需求,提出一种基于非均匀分布微结构的电容式柔性压力传感器,开展传感器性能调控研究.[方法]首先,基于敏感层微结构非均匀分布方式,提出一种灵敏度预测模型,并通过与实际测试结果的对比分析,验证模型的正确性.其次,研究当介电层微结构为微圆台时,不同微圆台顶面半径、高度、底面半径等几何参数以及次级微结构对传感器灵敏度和线性范围的影响.最后,基于该调控方法制备了综合性能良好的多级非均匀微结构分布的柔性压力传感器,进行性能测试与应用测试.[结果]非均匀分布微结构柔性压力传感器的灵敏度与微结构的分布及几何参数密切相关.通过对微结构分布的调控可筛选出具有最优灵敏度的传感器,对敏感层微结构几何参数的调控可实现对柔性压力传感器性能的调控.[结论]该性能调控方法对面向特定应用的传感器定制化设计具有一定的指导价值.
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[Objective] Generally,the sensitivity of capacitive flexible pressure sensors is affected by structural characteristics and geometric dimensions of the sensitive layer.Numerous studies have focused on establishing mathematical models to analyze and predict sensor sensitivity.However,most current research primarily concentrates on individual microstructural changes and pays little attention to analyses of microstructural distribution.Therefore,in this study,we consider the influence of distribution factors on the sensitivity and propose a predictive model for microstructures that are non-uniformly distributed.Additionally,based on this model,the optimal distribution form of microstructures is predicted.Finally,effects of different size parameters and multi-level microstructures on sensing performance are further analyzed. [Methods] First,a prediction model is established based on the theory of stress and deformation to predict the sensitivity of the sensor under different microstructure distributions in the sensitive layer.Second,for the purpose of using the predicted optimal distribution,PDMS is processed by a nanosecond ultraviolet laser (30 kHz,100 mm/s) so that sensitive layers with different microstructure sizes can be prepared.Subsequently,the prepared sensitive layer is placed between two ITO/PET films to assemble a flexible pressure sensor,and a sensitivity test is conducted to analyze the influence of the microstructure's size parameters and multi-stage microstructure on the sensor performance.Finally,the sensor with optimal parameters is prepared for performance and application testing. [Results] In this study,we present a mathematical model based on the non-uniform distribution of microstructures within the sensitive layer.In the model,the pressure on the corresponding microstructures is analyzed according to the distance relationship among them,and the deformation of the microstructures is further predicted.Based on the predicted microstructure deformation,the model predicts the sensitivity of the sensor in comparison with the actual measured value with the prediction error <7% in the low-pressure range (0-100 Pa).Additionally,we investigate the influence of distribution factors on sensor performance.The model can predict the microstructure distribution with the highest sensitivity under specific sensor size conditions.Furthermore,the influence of microstructure size parameters and multi-stage microstructures on sensor performance is discussed.Results indicate that the microstructure height exerts a relatively small influence on sensitivity and linear range under low-pressure conditions.However,the sensitivity can be significantly improved by reducing the radius of the top surface,albeit at the cost of reducing the linear range.Moreover,the bottom surface radius imposes an impact only slightly on the sensitivity,but quite noticeably on the linear range.Increasing the number of microstructures reduces the sensitivity while enhancing its linear range.To demonstrate the practicality of the research,we fabricate sensors corresponding to the predicted optimal microstructure distribution and test their performances and application suitability.In performance testing,these sensors exhibit fast response times (400 ms) and low detection limits (2.3 Pa).They also demonstrate excellent dynamic response stability and reliable repeatability under repeated exposure to different pressure sequences.In application suitability tests,they effectively distinguish the bending state and behave suitably for real-time monitoring of joint motion and similar applications.Additionally,they can accurately reflect respiratory changes in individuals under different states and differentiate among three facial expressions:expressionless,slight frowning,and frowning.
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[目的]对制造加工因素可能诱导的液体火箭发动机涡轮泵转子系统的涡轮叶片故障及其可靠性进行分析.[方法]首先总结叶片加工方法中可能会形成的加工缺陷并提取特征,然后选取具有代表性的缺陷因素构建缺陷-力学模型,通过有限元分析软件得到仿真结果,再采用模糊聚类分析的方法拟定评价指标,预测叶片寿命并计算由加工缺陷诱导的可靠性程度.[结果]制造加工因素会较大概率引起涡轮叶片的故障与可靠性问题.[结论]未来应在涡轮泵等重要核心零部件的可靠性分析中加入对制造加工因素诱导的故障分析,论文提出的研究方法对发动机涡轮叶片的可靠性预测及故障分析具有一定的理论指导意义.
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[Objective] In this paper,we analyze the turbine blade failures and the reliability of liquid rocket engine turbopump rotor systems.These failures and related reliability issues may be induced by manufacturing and processing factors. [Methods] Characteristics of possible machining defects are summarized and extracted for turbine blade part of liquid rocket engine turbo pump rotor system.Representative defect factors are selected to develop a defect-mechanical model,and simulation results are obtained by the finite element analysis software.The fuzzy cluster analysis is used to formulate the evaluation index,through which the blade life is predicted and the reliability induced by machining defects is computed. [Results] Based on our simulation results,we believe that faults and reliability issues in turbine blades are most probably caused by manufacturing and processing factors. [Conclusions] This study indicates that it is conducive to investigate faults and the reliability of turbine blades induced by manufacturing and processing factors.In addition,the research method proposed in this paper can offer a theoretical guide for reliability predictions and fault analyses of engine turbine blades.
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[目的]为了得到具有良好性能指标的移相全桥(PSFB)控制方案,本文提出了基于改进粒子群算法(IPSO)寻优的模糊比例积分微分(PID)控制方法.[方法]在PSFB的小信号模型基础上,使用模糊控制器改善PID的参数,随后应用自适应惯性权重和压缩因子法优化PSO的全局特性和收敛性,进而计算模糊控制器的比例因子和量化因子,以提高系统的控制效果.在Simulink仿真环境中分别使用常规PID、模糊PID、IPSO优化模糊PID三种方式对移相全桥拓扑进行仿真,并设计了一台100 W的样机,验证所提控制策略的有效性.[结果]仿真结果中,IPSO优化的模糊PID控制相对于常规PID和模糊PID,其调节时间、超调量、稳态误差分别下降79.6%、99.4%、42.9%和40.2%、20%、87.5%;基于TMS320F28034硬件的实验结果中,IPSO优化的模糊比例积分(PI)控制相对于增量式PI和模糊PI,其调节时间、超调量、稳态误差、电压输出纹波分别下降52.4%、56.4%、46.7%、75.0%和12.1%、37.4%、20%、66.7%.[结论]将IPSO应用于PSFB的PID控制,相对于常规PID和模糊PID,具有更高的控制精度、更快的收敛速度、更强的抗干扰能力.
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[Objective] As a typical DC-DC topology,phase-shifted full-bridge (PSFB) converter has been widely employed in aerospace,rail transit,and power systems among other fields.Numerous intelligent control methods of the converter help improve its energy conversion efficiency.To obtain a PSFB control scheme with ideal dynamic characteristics,herein we propose a fuzzy proportional-integral-derivative (PID) control method based on improved particle swarm optimization (IPSO). [Methods] Based on the operation principle of PSFB,a small signal model of PSFB was established. Afterwards,a fuzzy controller was introduced to improve the parameters of PID.Then adaptive inertia weight and compression factor method were used to optimize global characteristics and the convergence of PSO,which contributed to the computation of proportion factors and quantization factors of fuzzy controller.Conventional PID,fuzzy PID,and fuzzy PID optimized by IPSO were conducted to control the output voltage of PSFB in simulink and a hardware experimental platform based on TMS320F28034,respectively.Finally,anti-interference tests were conducted to verify the effectiveness of the proposed control strategy. [Results] First,the average computational time complexity of PSO and IPSO was evaluated from the average number of operations and average optimization results under different iterations.Results showed that,compared with PSO,IPSO could achieve the same optimization result with 80% fewer iterations and 5% less computational complexity.This outcome demonstrated that IPSO could achieve higher control precision in shorter total operation time.Simulation results also showed that,compared with conventional PID,the adjusting time of fuzzy PID and fuzzy PID optimized by IPSO was reduced by 65.9% and 79.6% respectively.In addition,compared with fuzzy PID,the steady-state error of fuzzy PID optimized by IPSO was reduced by 87.5%,and voltage ripples and overshoots were also improved to some extent.In taking ITAE as the adaptive value function,results showed that the ITAE value of fuzzy PID optimized by IPSO was clearly minimum,approximately 8.3% of conventional PID and 50% of fuzzy PID.Because incremental PI control is used in hardware experiments,corresponding results showed that the output voltage of PSFB under incremental PI control endured high frequency noises.In comparison,steady-state errors,overshoots and output ripples of output voltages under fuzzy PI control optimized by IPSO appeared all optimal,with reduction rates as 46.7%,56.4% and 75.0% respectively.In addition,time for output voltage's stabilization under fuzzy PI control optimized by IPSO shortened to the least,i.e.approximately 0.510 s.Results of simulations and hardware experiments showed that those two systems with the fuzzy controller secured stronger robustness and stability. [Conclusions] The proposed method manages to compensate for the defect of fuzzy control so that the automatic optimization of controller parameters is attained.Fuzzy PID optimized by IPSO secures higher control precision,faster convergence speed,stronger anti-interference ability and the fastest error-elimination speed.The optimal balance between control accuracy and convergence speed is achieved by fuzzy PID optimized by IPSO.Hopefully,the proposed control strategy provides an effective way to accomplish the intelligent control of other DC-DC converters.
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[目的]针对动量轮再入体姿态控制中存在转矩控制不足的问题进行研究.[方法]提出一种均匀对称斜装的动量轮布局,并利用拉格朗日第二类方程建立动量轮再入体的姿态动力学模型.基于动力学模型设计一种积分滑模综合控制策略,该策略考虑输入饱和对系统的影响,利用非线性扰动观测器对系统的不确定项进行估计.[结果]仿真与再入体模拟实验显示:在同样的控制需求下,本文提出的对称斜装动量轮布局所提供的最大转矩输出相较于传统正交的动量轮布局下降了60%.在引入输入饱和补偿的控制器作用下,控制输入可以更快地脱离饱和状态,再入体在4 s内稳定跟踪期望信号,稳定跟踪误差小于0.07°.[结论]本文提出的对称斜装动量轮布局通过动量轮之间的耦合,提高了动量轮的利用效率.相较于传统滑模控制,本文提出的积分滑模综合控制策略在再入体姿态控制上有抖振低、相对超调量小、鲁棒性高的优点,可有效地对再入体的姿态调整进行精确控制.
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[Objective] This study focuses on reentry bodies that utilize momentum wheels as their actuation mechanisms,with a specific emphasis on addressing torque control deficiencies in the context of reentry-body attitude control.While concurrently preserving the symmetry of the reentry body,we propose a novel momentum-wheel layout that enhances the maximum torque output in the yaw,pitch,and roll channels.Additionally,a control scheme is introduced for the designed momentum wheel-based reentry-body system with the aim of achieving both the stability in attitude during reentry and agile attitude maneuvers. [Methods] In addressing the issue of insufficient torque output in momentum wheel-based reentry bodies,this paper introduces a symmetric layout for momentum wheels to improve the balance and maximize the torque output in individual channels.Due to the leverage of Lagrange's second-kind equations,a dynamic model for the attitude dynamics of the momentum wheel reentry body is developed.The study employs sliding mode control theory for tracking and controlling the attitude of the reentry body.For the purpose of mitigating the chattering issue associated with the sliding mode controller,a low-pass filter is incorporated with the controller to enhance system damping.Mathematical modeling is applied to characterize the reentry body with the added low-pass filter.Subsequently,in the presence of uncertain parameters and external disturbances that challenge precise estimation,we introduce a disturbance observer to compensate for uncertainties and enhance the robustness of the controller.Finally,an integral sliding mode control law is devised,and an input saturation compensation signal is introduced within the sliding mode control to reduce the impact of input saturation on the system. [Results] In this study,we employ both MATLAB simulations and a reentry-body simulation experimental platform to validate the effectiveness of the proposed momentum wheel layout,the designed controller,and the input saturation compensation strategy.Initially,during extensive maneuvering control simulations,a comparison of the maximum torque outputs for different momentum wheel layouts reveals a 60% decrease in the maximum torque output provided by the novel momentum layout proposed in this paper,compared to the traditional orthogonal layout.Subsequently,to validate the effectiveness of the designed controller,we rely on simulation examples to demonstrate the rapid and stable achievement of the desired trajectory by the reentry body.The yaw angle stabilizes within 4 s,with tracking errors in yaw and pitch angles stabilizing below 0.07°.In trajectory tracking experiments on the reentry-body experimental platform,the designed controller exhibits faster adjustment times and smaller overshoot in comparison to the traditional sliding mode controller.The spectral analysis indicates a 44.57% reduction in the maximum spectral amplitude at a stable state compared to the traditional sliding mode controller,and reaches 46.83 dB.Under parameter variations in the controlled object,the reentry-body simulation platform under the control of the traditional sliding mode controller exhibits pronounced oscillations during the balance process.In contrast,the designed controller,which incorporates filters and disturbance observers,effectively alleviates the burden on brushless motors,resulting in smoother attitude tracking curves and reduced system jitters.Finally,in the simulation verifying the effectiveness of input saturation compensation,the controller without input saturation compensation leads to significant oscillations and even instability.The introduction of input saturation compensation allows the control input to exit the saturated state more quickly,thus demonstrating the efficacy of the compensation strategy.
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[目的]为了提高控制效率,研究时滞和非时滞驱动响应网络脉冲同步的自适应二次反馈控制.[方法]本文运用了Lyapunov函数、椭球边界点参数化和脉冲微分比较定理,研究了在时滞和非时滞情况下驱动响应网络的脉冲同步问题.[结果]在本文所设计的自适应二次反馈控制器的作用下,驱动网络系统和响应网络系统在椭球体ε(P)={e∈R~n~2:e~TPe≤1}内达到同步.以单能源系统为网络节点,含二次项的自适应脉冲控制比不含二次项的自适应脉冲控制误差更小,同步更快.[结论]对于驱动响应网络脉冲同步的自适应反馈控制问题,引入二次项的反馈控制器可以提高同步速度,降低同步误差.
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[Objective] The research of impulsive synchronization in complex networks has obtained abundant achievements,but there are few results on impulsive synchronization in drive-response complex networks driven by adaptive quadratic feedback control.Compared to the results of conventional impulsive synchronization,the control efficiency is better improved by designing a new adaptive secondary feedback controller. [Methods] In this paper,the Lyapunov function,the parameterization of ellipsoid boundary points and the theorem of impulse differential are applied to study the impulsive synchronization problem of time-delay and non-time-delay drive-response complex networks. [Results] With the adaptive quadratic feedback controller and adaptive law designed in this paper,By two theorems we can conclude that the error system is asymptotically stable in both time-delay and non-time-delay cases such that the trajectories of drive-response complex networks do not run out of the ellipsoid and are synchronized within the ellipsoid ε(P)={e∈R~n~2:e~TPe≤1}.We provide a framework for dealing with complex network synchronization problems with both quadratic terms and impulsive control.Finally,taking the single energy system as the nodes of the networks,a numerical example is given to verify the effectiveness and feasibility of the obtained results. [Conclusions] We can see that the system reaches synchronization faster with adaptive impulsive control containing a quadratic term.
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[目的]针对基于深度神经网络频谱估计的麦克风阵列算法存在数据依赖的问题,提出了一种基于深度学习的混响感知麦克风阵列语音增强算法.[方法]首先利用麦克风阵列波束形成输出与原始信号做互相关,以近似房间冲激响应的形式获取当前环境的混响特性作为LSTM网络的输入,网络模型以干净语音为目标进行训练从而输出房间冲激响应泛化向量,最后通过组合近似房间冲激响应与房间冲激响应泛化向量获得后置抗混响滤波器系数,实现语音增强.[结果]仿真和实验结果中,与波束形成、加权预测误差算法和传统深度学习去混响算法相比,所提出的方法在不同混响场景下具有更好的表现.[结论]本文方法在不同混响场景下都具有相对稳定的抗混响能力,具有较好的泛化性能.
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[Objective] The technique of microphone array has been extensively applied for enhancing speech by means of the exploration of spatial information provided by multiple microphone channel.However,due to diverse reverberation characteristics produced by different sizes,different boundary materials and different reflectors,the speech enhance performance of microphone array are deteriorated significantly.In recent years,the deep-learning optimized microphone array signal processing has been investigated to remedy the problem caused by reverberation,which endures the data dependence and thus cannot adapt to the reverberation scene that is excluded from the training data.In this paper,a novel reverberation-aware (RA) microphone array speech enhancement algorithm is proposed to first obtain the reverberant feature and then design a deep-learning model to decouple the negative impact of environments,thus facilitating environment adaptive microphone array speech enhancement under diverse reverberant scenarios. [Methods] The proposed RA microphone array speech enhancement algorithm consists of training stage and testing stage.Specifically,in the training stage,the simulated reverberant signal is used for obtaining approximate room impulse response (ARIR) by correlating the reverberant signal with its beamforming output.Then,with the clean speech as training target,a RA model is designed by adopting ARIR and the beamformed signal as the training input.Consequently,a diverse room impulse response (RIR) generalized vector (RGV) to generalize the de-reverberation model with respect to RIR as well as the uncontrolled speech can be produced.In the practical testing stage,the practical ARIR is similarly obtained by correlating the received reverberant signal with its beamforming output.Afterward the resulting RGV is used to convolve with the practical ARIR to obtain the coefficients of a post de-reverberation filter,which exerts to remove the reverberation corresponding to ARIR. [Results] Performance of the proposed RA speech enhancement algorithm is quantitatively evaluated through simulations and experiments,in which the classic filter and sum beamforming (FSB) algorithm,weighted prediction error (WPE) algorithm,and DNN-WPE algorithm are chosen as comparative methods.The perceptual evaluation of speech quality (PESQ) scores and the speech-to-reverberation modulation energy ratio (SRMR) serve as evaluation metrics for assessing speech quality.Also,the THCHS-30 dataset is utilized for training and testing.In the case of environment match,those datasets for model training and testing originate from the same room,whereas,in the case of environment mismatch,those datasets for model training and testing originate from different rooms.In the simulation,artificial RIR with different reverberation levels are constructed based on the IMAGE toolbox,and speech signals with different reverberation levels can be generated by convolving the aforementioned original pure corpus with the artificial RIR to simulate the reverberant multichannel received signals of microphone arrays.Simulation results show that,under the condition of environment match,both DNN-WPE and the proposed RA deep learning algorithms outperform the traditional FSB algorithm and WPE algorithm at all reverberation levels.However,in case of environment mismatch,the performance of both DNN-WPE and the proposed RA algorithms worsen.Notably,while the DNN-WPE experiences significant performance degradation in terms of PESQ and SRMR,the proposed RA algorithm continues to exhibit better performance than the traditional FSB algorithm and WPE algorithm do.In the practical experiment,speech data is recorded with reverberation times of 0.25,0.4,and 0.6 s in a reverberation laboratory with adjustable reverberant level.
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[目的]针对智能终端小型化、使用场景多样化的发展趋势,研制一种既能满足严苛的尺度、算力、存储空间限制,又能实现环境自适应的双麦语音增强算法.[方法]考虑到麦克风阵列波束形成算法可以增强期望方向信号,同时抑制非期望方向的噪声,但小尺寸阵列波束主瓣波束宽度较宽、影响增强效果.在小尺寸双麦对目标方向进行波束对准增强的基础上,参考干扰方向噪声,进一步对目标方向语音进行谱减处理,并引入角度压制比实时检测干扰方向噪声的能量估计,实现对不同混响、噪声类型的自适应处理,从而提升语音增强效果.[结果]角度压制比随混响时间增加而增大,与信噪比不相关.相对于原始带噪信号、滤波-累加波束形成(filter-and-sum beamforming,FSB)信号、FSB结合固定对向谱减的语音增强信号,通过FSB结合角度压制比自适应对向谱减得到的语音增强信号,在不同噪声类型、不同信噪比和不同混响时间下,均能得到最高的分段信噪比得分和大多数的最高客观语音质量评估得分.[结论]角度压制比能一定程度地反映不同的混响情况,利用角度压制比得到的谱减阈值具有一定的环境适应性.
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[Objective] The voice front-end plays an important role in collecting and ensuring the quality of speech signals so that different types of speech processing can be supported.The increasing application of small size intelligent terminals in highly diverse application scenarios brings significant challenges to the speech enhancement performance of the voice front-ends under complicated reverberant and noisy environments.As the beam directivity of microphone array beamforming algorithm depends highly on microphone array sizes and element numbers,dual-microphones that are popularly adopted in small size intelligent terminals endure substantial performance degradation.In this paper,an environment adaptive dual-microphone speech enhancement algorithm based on direction mitigation ratio spectral subtraction is proposed to improve the speech-enhancement performance of dual-microphone array under different environments. [Methods] First,a least-squares (LS) driven filter-and-sum (FSB) dual-microphone beamformer is designed to yield the preliminary speech enhancement with its signal beam and noise beam aiming at desired directions and undesired directions,respectively.Then,the noise reference collected by the noise beam is used to remove residual noises that are contained in the beamforming enhanced speech by the way of spectral subtraction.Specifically,a direction mitigation ratio (DMR) parameter is defined to carry the environmental information,which is calculated in each frame to determine the spectral subtraction threshold.Thus,by updating the DMR in real time,the spectral subtraction processing between the enhanced speech and noise reference is adaptively controlled to achieve environmental prediction and achieve improved effects of residual noise removing. [Results] For the purpose of performance evaluation and comparison,practical experiments are carried out in anechoic laboratory,in which speakers located in different directions are used as artificial noise resources to generate environmental noises with different signal-to-noise ratios (SNRs).Experimental data collected by the microphone array is used to generate reverberated signals with different reverberation levels using the IMAGE reverberation model to verify the impact of environmental changes on experimental results.In these practical experiments,segment signal-to-noise ratio (segSNR) and perceptual evaluation of speech quality (PESQ) score are adopted as quantitative evaluation metrics.Experimental results under different noisy and reverberant environments reveal that the proposed algorithm can effectively remove residual noises of FSB,and that the waveform is the closest to the pure speech.In terms of segSNR,the algorithm proposed herein outperforms FSB under different signal-to-noise ratios,noise types,noise angles,and reverberation times.Compared to FSB and the fixed spectral subtraction threshold method,the proposed method achieves an average segSNR improvement of 2.97 and 2.75 dB,respectively.In terms of the PESQ score,we also obtain the best results,indicating better subjective listening feeling.Under a reverberation time of 0.2 s,the proposed algorithm yields an average PESQ improvement of 0.76 points at an SNR range of -5 to 10 dB,corresponding to an average improvement of 0.36 points and 0.16 points compared to the FSB and the fixed spectral subtraction method respectively.Meanwhile,the capability of the DMR parameter in characterizing environmental patterns has also been verified,thus offering an adaptive adjustment mechanism for the proposed method under different environment. [Conclusions] Experimental results and analyses show that,by combining the traditional FSB beamforming with the spectral subtraction processing,the proposed algorithm is capable of achieving promising speech enhancement performance under different noisy and reverberant backgrounds.
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[目的]针对目前两种近场动力学(PD)理论,键型PD(BPD)无法应用三维材料本构模型,而态型PD在均匀化过程中出现零能模式常导致强非线性问题不稳定的挑战,研究一种新型混合PD(HPD),以增强PD理论在求解复杂强非线性问题时的稳定性和实用性.[方法]HPD方法结合BPD和SPD的优点参照BPD,将PD点与影响域内其他PD物质点相连形成键,键上的力通过键中点截面上的应力及其法向向量的乘积计算得到,应力可由三维本构关系计算,而应变则使用与SPD类似的方法拟合得到.在HPD中,键力方向与键的方向并不一致.最后通过两个数值算例验证了HPD方法的正确性和稳定性.[结果]在第一个算例中,可以观察到两种影响域半径的HPD和有限元方法(FEM)的结果高度相似.力加载行(M-M)中的最大相对误差仅为4.58%,模型顶行(N-N)中的最大相对误差仅为0.51%.相比之下,由于零能模式的存在,SPD的最大相对误差为382.68%和5.61%.在第二个算例中,选择A点作为代表点,比较了3种方法计算的位移时程.在靠近底座的A点,SPD在位移计算的初始阶段表现出较高的精度.然而,当模型进入强非线性时,误差便会显著增加,达到约65.65%.相比之下,HPD有效地解决了这个问题,在最大位移点实现了仅0.2%的相对误差.[结论]HPD可以消除零能量模式的影响,而且在各种影响域半径下都能产生更准确的结果;即使在强非线性情况下HPD也能解决零能模式问题,同时可确保应力和应变的精确预测,可有效解决强非线性和大变形问题.此外,HPD可以与各种材料模型相结合,是一种实用且有效的计算方法,可用于解决各种复杂问题.
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[Objective] Presently,as a non-local continuum theory effective for diverse discontinuous problems,Peridynamics (PD) is classified into two types,namely bond-based peridynamics (BPD) and state-based peridynamics (SPD).However,the former cannot be applied to three-dimensional constitutive material models,and the latter encounters zero-energy modes in the homogenization process,leading to the instability in strongly nonlinear problems.To face these challenges,here we introduce a hybrid peridynamics method (HPD) that combines merits of both BPD and SPD to surpass the existing constraints.This proposed approach aims to enhance the stability and the applicability in complicated nonlinear problems. [Methods] In HPD,BPD methods are extended,PD points are connected within an influence domain to form bonds,while the force is computed on these bonds through the stress on their midpoint sections and corresponding normal vectors.Herein,this stress is derived with the three-dimensional constitutive relationship.Additionally in HPD,midpoint's strains are computed similarly to state-based PD.Notably,the force direction on the bond does not align with the direction of bonds all the time. [Results] Two numerical examples are presented to validate the correctness and the stability of the HPD method.In the first example,the static analysis is utilized to simulate the deformation of a two-dimensional elastic column under the influence of concentrated force loads.The second example investigates the dynamic time history response of a two-dimensional soil column in incorporation of multi-yield surface materials subjected to earthquake base excitations.For these computations,implicit solutions and static equilibrium PD equations are applied,and solutions are computed using the Newton-Raphson method.In the first example,it is observed that HPD and finite element method (FEM) yield close results for two horizon sizes.The maximum relative error in the force loading row (M-M) lies in a mere 4.58%,and in the top row of the model (N-N),it lies in a mere 0.51%.In contrast,due to the presence of zero-energy mode,SPD exhibits maximum relative errors of 382.68% and 5.61% in the same comparisons.This outcome suggests that HPD not only eliminates the impact of zero-energy mode but also produces more accurate results under various horizon sizes.In the second example,point A is chosen as the representative point,and the displacement time histories computed by the three methods are compared.Notably,at point A closer to the base,SPD demonstrates greater accuracy in initial stages of displacement computations.However,as the model enters strong-nonlinearity zones,substantial errors become apparent,and the maximal relative error of SPD reaches 65.65%.In contrast,HPD effectively tackles this issue,achieving a mere 0.2% relative error at the point of maximal displacement.This comparison emphasizes that HPD can eliminate oscillations caused by zero-energy mode,thereby proficiently addressing challenges related to strong nonlinearity and large deformation while ensuring precise predictions of stresses and strains. [Conclusions] For severely nonlinear problems,HPD that combines merits of BPD and SPD is proposed.Two examples,which are involved,respectively,with statics and dynamics,are presented to demonstrate the ability of HPD in tackling computational stability and accuracy.Finally,it can be combined with various material models,thus hopefully in the future serving as a practical and effective tool that can be used for a wide range of severely-nonlinear problems.
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[目的]考虑需要承担金融风险的情况下代理人的决策问题的效用函数满足的方程u_(xx)+uu_y-u_t=f(x,y,t,u),此方程属于强退化抛物方程,如何选择合适的边界条件使得其弱解具有唯一性和稳定性是一个具有本质难度的问题.[方法]通过选取合适的检验函数,找到了适用于此强退化抛物方程的部分边界条件的表达式.[结果]改进了相关文献的结果,并利用Kruzkov双变量方法讨论了该方程在部分边界条件下BV熵解的稳定性;并在一定条件下探讨了独立于边界条件下的稳定性问题,给出了具体的例子.[结论]揭示了非线性退化抛物方程边界条件与空间变量所在的区域的几何性质具有密切的联系,这是一个容易被忽略但又是非线性退化抛物方程边界条件所具有的本质特征,因此具有比较重要的理论意义.
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[Objective] Consider the equation of the utility function for agent's decision under financial risk u_(xx)+uu_y-u_t=f(x,y,t,u),which belongs to the group of strongly degenerate parabolic equations.How to choose a suitable boundary such that the uniqueness and the stability of weak solutions are true constitutes a challenging problem. [Methods] By choosing a suitable test function,a partial boundary-value condition is found to match up with this strong degenerate parabolic equation. [Results] Such a result improves the result reported in the relevant literature.Under a partial boundary-value condition,by Kruzkov bi-variables method,we discuss the stability of BV entropy solutions of the equation.Moreover,the stability independent of any boundary value condition is discussed,and some explicit examples are given. [Conclusion] The conclusion reflects on the essential characteristic of a nonlinear degenerate parabolic equation,in which its partial boundary value condition secures a close relationship with the geometry of the domain.Hopefully,the theoretical significance of our work can contribute to the math community.
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[目的]目前空间分布阶方程的求解多为时间整数阶,且空间的收敛阶大多为二阶和三阶,很难达到四阶,为了提高Riesz空间分布阶Caputo时间分数阶扩散方程求解过程中的空间收敛精度,提出一种高阶的有限差分法.[方法]基于数值解法对Caputo时间分数阶导数采用L1插值逼近离散;分布阶导数利用复化Simpson求积公式,将分布阶微分方程转化为一个多项Riesz空间分数阶导数的微分方程;从而构造方程的高阶数值离散格式,并运用矩阵分析的方法证明该数值格式具有稳定性和收敛性.[结果]在求解该分布阶微分方程中,该数值方法使得空间和分布阶的收敛阶达都达到了四阶,时间上的收敛阶达到了2-β阶.[结论]本文构造出的Riesz空间分布阶Caputo时间分数阶扩散方程的高阶差分格式,可使得空间上的收敛阶达到四阶,适用于高精度求解场景.
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[Objective] Effectively,distributed-order differential equations can describe anomalous diffusion phenomena in multifractal media.Regarding the solution of spatial distributed-order equations,we find that the integer order is mostly studied in the time domain,whereas the spatial convergence order is mostly second and third orders,resulting in difficulties to achieve fourth order.To improve the spatial convergence accuracy in solving the Riesz spatial distributed-order Caputo time fractional diffusion equation,herein we propose a high-order finite difference method. [Methods] By using the composite Simpson quadrature formula,the distributed differential equation is transformed into a multi-term fractional derivative differential equation in Riesz space,and the fractional derivative of Caputo time is approximated by L1 interpolation.Next,the high-order numerical discrete scheme of the equation is constructed and the stability and convergence of the scheme are proved by the matrix analysis.Finally,a numerical example is given to demonstrate the stability and convergence of the scheme. [Results] In solving this distributed-order differential equation,our numerical method achieves a spatial convergence order of four for both spatial and distributed orders,and a time convergence order of 2-β. [Conclusions] We construct a high-order difference format for the Riesz spatial distributed-order Caputo time fractional diffusion equation and achieve a spatial convergence order of four.Because distributed-order equations with spatial convergence orders have been studied mostly at the second or third order,the effectiveness of the proposed method is observed.
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[目的]由于流行病会随着时间的变化而发生变化,因此,结合现实情况,研究一种受接种疫苗比率和免疫率影响的带时变性质的SVEIR疾病传播模型的平衡点的动力学性质.[方法]首先,通过构建动力学模型研究平衡点的存在性;其次,利用下一代矩阵法得出模型的基本再生数R_0和有效再生数R_e;最后,通过Lyapunov定理和Routh-Hurwitz判别方法对病毒的基本再生数和有效再生数进行稳定性分析.[结果]通过python数值仿真实验,得出当R_0<1时,疾病会消失;当R_0>1时,流行病会转化为地方流行病;当R_0=1时,系统会出现临界分岔现象.[结论]接种疫苗是疾病防控的关键措施之一.R_0的取值决定流行病的演化结果.
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[Objective] Generally,because epidemic will change with time,the dynamics of the equilibrium point of a time-varying SVEIR disease transmission model affected by the vaccination rate and immunization rate is studied by combining with the reality. [Methods] First,the existence of equilibrium point was studied by constructing a dynamics model;Second,the basic regeneration numbers R_0 and effective regeneration numbers R_e are obtained by using the next generation matrix method;Finally,the stability of the basic regeneration numbers and effective regeneration numbers were analyzed by using Lyapunov theorem and Routh-Hurwitz discrimination method. [Results] Through python numerical simulation experiment,it is obtained that when R_0<1,the disease will disappear;When R_0>1,the epidemic will transform into a local epidemic;When R_0=1,the system will have a critical bifurcation. [Conclusions] Vaccination is one of the key measures of disease prevention and control.The value of vaccine R_0 determines the evolution of epidemic.
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[目的]为评价网络容错性,以具有高对称性和递归结构的Bubble-sort网络为研究对象,确定其h-extra r-分支边连通度.[方法]Bubble-sort网络B_n可以分解成n个子图B_n(i),其中B_n(i)是由点集{x_1x_2...x_n:x_n=i}(1≤i≤n)导出的子图,并且B_n(i)同构于B_n-1,利用它的结构特点,用数学归纳法推理证明了主要结果.[结果]确定了bubble-sort网络的h-extra r-分支边连通度cλ_3~2(B_n)=4n-10(n≥4).[结论]研究了bubble-sort网络的一类条件连通度,可用于衡量网络的可靠性.今后将继续深入研究bubble-sort网络的其他条件连通度.
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[Objective] As one of intensively-investigated research topics in network fault tolerance,the bubble-sort network secures good properties,such as high symmetry and recursive structure.Herein,we determine the h-extra r-component edge connectivity of bubble-sort networks. [Methods] The bubble-sort graph B_n can be partitioned into n subgraphs B_n(i),where B_n(i) denotes the induced subgraph by the set of vertex {x_1x_2...x_n:x_n=i} for 1≤i≤n and isomorphic to B_n-1.According to its structural characteristics,we use mathematical induction to infer and prove main results. [Results] We determine the h-extra r-component edge connectivity of bubble-sort networks,i.e.cλ_3~2(B_n)=4n-10(n≥4). [Conclusions] The conditional connectivity can be used to measure the reliability of a network.We investigate a type of conditional connectivity of bubble-sort networks,and plan to continue studying other conditional connectivities of bubble-sort networks in the future.
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[目的]利用最省刻度尺的已有研究成果研究极小优美图的构造方法.[方法]对任意正整数n≥2,在长度是n的无刻度直尺上最少刻多少个刻度,就能度量1-n的所有长度,这就是最省刻度的尺子问题.给定正整数n,存在m个整数组成的集合{a_i},满足0=a_1
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[Objective] For any positive integer n≥2,it is possible to measure all lengths from 1 to n by carving at least a few scales on an ungraduated ruler of length n.This is the problem of the ruler with the least number of scales.Given a positive integer n,there exists a set of m integers {a_i},which satisfies 0=a_1<a_2<...<a_m=n,so that any integer s (0≤s≤n) can be expressed as the difference a_j-a_i between the two elements in the set.Therefore,{a_i} is called the restricted difference basis on n.The ruler with the least number of divisions,restricted difference basis,and representation of graceful graphs are three unresolved mathematical problems. [Methods] According to the definitions of minimal graceful graphs and restricted difference basis,the construction of "ruler with the least number of divisions","minimal graceful graph",and "restricted difference basis" is the same mathematical problem. [Results] The conclusion is that K_n is not a graceful graph when n≥5,and K_4+Kn is a graceful graph when n≥1.The upper and lower bounds on the number of vertices of minimal graceful graphs with edges ranging from 6 to 82 are obtained; The graceful labels of graphs K_3∨K_(1,3,n)-3e,K_3,n∨K_3-e and K_(2,3,n)∨K_3-7e are given using construction methods,thus proving that these three types of graphs are all graceful graphs.Moreover,when 0≤n≤9,K_3∨K_(1,3,n)-3e and K_(2,3,n) ∨K_3-7e are all extremely graceful graphs.When 0≤n≤ 8,K_3,n∨K_3-e are all extremely graceful graphs,and 29 sets of scale values for the most economical rulers are given. [Conclusions] As the length n of the ruler increases,a set of scale values for this ruler needs to be calculated.Minimum scale value will become very difficult.At present,there is no literature on using the method of constructing graceful graphs to obtain the most economical scale value design.This article proposes a new approach to solve the problems of the most economical scale and restricted difference basis by using the method of constructing minimal graceful graphs.
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【目的】分析和阐明沟眶象Eucryptorrhynchus scrobiculatus味觉受体基因EscrGR8的分子特性和功能,揭示其调节雌成虫繁殖力的作用。【方法】基于沟眶象触角转录组数据库,采用RACE克隆EscrGR8的cDNA全长序列;利用qRT-PCR检测EscrGR8在沟眶象不同发育阶段(卵、 1-6龄幼虫、蛹、雌成虫和雄成虫)和雌雄成虫组织(去除触角和喙的头、触角、口器、中肠、前足、睾丸、卵巢、雄虫交配器和雌虫产卵器)中的表达量。显微注射雌成虫dsRNA后0, 6, 12, 24, 36, 48和72 h时利用qRT-PCR检测RNAi后EscrGR8的表达量。检测显微注射dsEscrGR8后1-5 d和6-11 d时沟眶象雌成虫在不同土壤含水量(0~10%, 11%~20%, 21%~40%, 41%~60%, 61%~80%和81%~100%)条件下的产卵选择率、总产卵数量和所产卵的孵化率,研究抑制EscrGR8表达对雌成虫产卵选择性和繁殖力的影响。【结果】成功克隆了沟眶象EscrGR8(GenBank登录号: OR836580)的cDNA全长序列,开放阅读框(ORF)长1 251 bp,编码了416个氨基酸,具有6个跨膜结构域。多序列比对和系统发育进化分析结果表明, EscrGR8与其他昆虫的GR的氨基酸序列同源性普遍较低,其中与棉铃象甲Anthonomus grandis的AgraGR64f氨基酸序列一致性为3096%。qRT-PCR检测结果表明, EscrGR8在沟眶象不同发育阶段和成虫组织中的表达量具有显著差异, EscrGR8在雌成虫中的表达量最高,在卵中的表达量最低;EscrGR8在雌成虫卵巢中特异性高表达。显微注射dsEscrGR8不仅在一定时间内显著降低EscrGR8的表达量,并且对雌成虫的产卵选择性具有显著影响。显微注射dsEscrGR8后1-5 d时沟眶象雌成虫在含水量21%~40%土壤条件下的产卵选择率和所产卵的孵化率与显微注射dsGFP的对照组相比分别显著降低了2466%和1583%;在含水量81%~100%土壤条件下的产卵选择率与显微注射dsGFP的对照组相比显著增加了28.39%,雌成虫所产卵几乎不孵化。【结论】本研究证实了味觉受体基因EscrGR8对沟眶象雌成虫产卵选择和繁殖力的影响,有助于理解昆虫味觉受体基因的多样性和功能特异性。
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【Aim】 To analyze and elucidate the molecular characteristics and function of the gustatory receptor gene EscrGR8 in Eucryptorrhynchus scrobiculatus, and to reveal its role in the regulation of the fecundity of female adult. 【Methods】 Based on the antennal transcriptome database of E. scrobiculatus, the cDNA full-length sequence of EscrGR8 was cloned using RACE. The expression levels of EscrGR8 in different developmental stages(egg, 1st-6th instar larvae, pupa, female adult, and male adult), and female and male adult tissues(head without antennae and proboscis, antennae, mouthparts, midgut, forefoot, testicles, ovaries, male copulatory organ and female ovipositor) of E. scrobiculatus were detected by qRT-PCR. The expression levels of EscrGR8 at 0, 6, 12, 24, 36, 48 and 72 h after RNAi through microinjection of dsRNA into female adults were detected by qRT-PCR. The oviposition selection rates, total numbers of eggs laid and hatching rates of eggs laid by female adults under different soil moisture conditions(0-10%, 11%-20%, 21%-40%, 41%-60%, 61%-80%, and 81%-100%) at 1-5 d and 6-11 d after dsEscrGR8 microinjection were determined, and the effects of inhibition of the EscrGR8 expression on the oviposition preference and fecundity of female adults were studied. 【Results】 The full-length cDNA sequence of EscrGR8(GenBank accession no.: OR836580) of E. scrobiculatus was successfully cloned with the open reading frame(ORF) of 1 251 bp in length, encoding 416 amino acids. EscrGR8 has six transmembrane domains. Multiple sequence alignment and phylogenetic analysis results showed that EscrGR8 has a low homology to the GRs of other insects, and the amino acid sequence identity with AgraGR64f of Anthonomus grandis is 30.96%. qRT-PCR result showed that there were significant differences in the expression levels of EscrGR8 in different developmental stages and adult tissues of E. scrobiculatus. EscrGR8 had the highest expression level in female adults, and the lowest expression level in eggs. EscrGR8 was highly expressed specifically in the female ovaries. Microinjection of dsEscrGR8 not only significantly reduced the expression level of EscrGR8 within a certain period of time, but also had a significant impact on the oviposition preference of female adults. At 1-5 d after microinjection of dsEscrGR8, the oviposition selection rate and hatching rate of eggs laid by female adults under soil condition with the moisture content of 21%-40% were significantly reduced by 2466% and 1583%, respectively, compared with those of the dsGFP-microinjected control group. The oviposition selection rate increased significantly by 28.39% under soil condition with the moisture content of 81%-100%, and almost all of the eggs laid by female adults failed to hatch. 【Conclusion】 This study has confirmed the effect of gustatory receptor gene EscrGR8 on the oviposition preference and fecundity of female adults of E. scrobiculatus, which is helpful for understanding the diversity and functional specificity of gustatory receptor genes in insects.
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【目的】羧酸酯酶(carboxylesterases, CCEs)是一类重要的水解酶超家族,参与昆虫体内各种外源物质的代谢过程。本研究利用不同发育阶段、不同组织和吸血前后中华按蚊Anopheles sinensis的转录组数据分析CCE基因表达模式,为进一步研究CCEs在不同生理过程中的潜在功能奠定基础。【方法】以前期从中华按蚊实验室品系转录组数据库中筛选出的50个CCE基因,利用生物信息学分析其在中华按蚊不同发育阶段(卵、1 -4龄幼虫、雄蛹、雌蛹、雄成蚊和雌成蚊)、成蚊不同组织(触角、唾液腺、中肠、马氏管、精巢、卵巢、表皮和脂肪体)中以及雌成蚊吸血前和吸血后不同时间(1, 3, 6, 12, 24和48 h)的表达模式。【结果】CCE基因主要在幼虫或成蚊阶段高表达或特异性表达;AsAe12, AsAe4和AsBe4在所有发育阶段均高表达。CCE基因的表达具有组织特异性,主要集中在成蚊触角、表皮和精巢中表达;此外,5个CCE基因(AsAe13, AsAe12, AsAe6, AsAe4和AsBe4)在成蚊中肠、马氏管和脂肪体中均高表达,可能与这些解毒器官代谢异生物有关。在雌成蚊吸血后,大多数CCE基因的表达量发生了变化,它们的表达模式也存在差异,这表明血液消化是一个复杂的过程。【结论】本研究结果丰富了中华按蚊CCE基因的知识,为深入探究CCE家族基因在中华按蚊生长发育中的的潜在功能提供有价值的参考。
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【Aim】 Carboxylesterases(CCEs) are an important hydrolase superfamily and have a role in the metabolism of various exogenous substances in insects. This study aims to lay a foundation for further research on the potential functions of CCEs in different physiological processes by analyzing the expression patterns of CCE genes from transcriptome datasets of Anopheles sinensis at different developmental stages, in different tissues, and before and after blood meal. 【Methods】 Based on 50 CCE genes collected from the obtained transcriptome data of the An. sinensis laboratory strain, the expression patterns of CCE genes in An. sinensis at different developmental stages(egg, 1st-4th instar larvae, male pupa, female pupa, male adult and female adult), in different adult tissues(antennae, salivary gland, midgut, Malpighian tubules, testis, ovary, cuticle and fat body), and female adults before and after blood meal(at 1, 3, 6, 12, 24 and 48 h) were analyzed by bioinformatics. 【Results】 CCE genes were mainly highly or specifically expressed in the larval or adult stages. AsAe12, AsAe4 and AsBe4 were highly expressed during all developmental stages. The expression patterns of CCE genes were also tissue specific and mainly expressed in antennae, cuticle and testis of adults. Moreover, five CCE genes(AsAe13, AsAe12, AsAe6, AsAe4 and AsBe4) were highly expressed in the midgut, Malpighian tubules and fat body of adults, suggesting their potential involvement in xenobiotic metabolism within these detoxification organs. After feeding female adults with blood meal, the expression levels of most CCE genes changed, and their expression patterns were different, suggesting that the blood digestion is a complex process. 【Conclusion】 The results of this study have enriched the knowledge of CCE genes in An. sinensis, providing a valuable reference for further research on the potential function of CCE family genes in the growth and development of An. sinensis.
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【目的】筛选出促黑化条件下中华按蚊Anopheles sinensis蛹体壁中表达变化最显著的基因类群,并初步探究它们与黑色素前体累积及表皮结构特征间的相关性。【方法】在Grace,s昆虫细胞培养基中添加黑色素前体多巴(dopa)和多巴胺(dopamine),对化蛹20 min内中华按蚊体壁进行体外培养,对照组(CK)中不添加黑色素前体,培养16 h时利用体视显微镜观察黑色素前体处理组与对照组蛹体壁着色和表皮截面特征;通过Illumina测序平台对黑色素前体处理组与对照组蛹体壁进行转录组测序,对差异表达基因(different expression genes, DEGs)进行GO功能分类和KEGG通路富集分析;分析被显著富集的基因注释和染色体分布;利用qRT-PCR验证转录组数据。【结果】多巴和多巴胺处理组中华按蚊蛹体壁与表皮截面相比于CK明显黑化,且多巴处理组着色程度最深;多巴和多巴胺处理组中华按蚊蛹表皮相比于CK明显增厚,且增厚程度与黑化程度相关。多巴处理组vsCK与多巴胺处理组vsCK比较组的DEGs分别为2 952和697个,且下调基因居多;这两类比较组间共有上调的DEGs有223个,共有下调的DEGs有347个。DEGs的GO功能注释结果表明,在上述比较组以及两比较组间共有的上调DEGs被显著富集到表皮结构组分(GO: 0042302)。KEGG通路富集分析结果显示,多巴处理组vsCK比较组上调的DEGs被显著富集到剪切体通路,下调的DEGs被显著富集到Toll-Imd和Hippo信号通路;在多巴胺处理组vsCK比较组中下调DEGs被显著富集到自噬通路;这两比较组间共享的DEGs没有被显著被富集的通路;65个被富集的上调表皮蛋白基因来自于CPR, CPF, TWDL, CPLC和CPAP5个家族,并分布于3条染色体,其中部分成员成簇分布。qRT-PCR结果显示,两比较组中所选择的共有上调的12个表皮蛋白基因的表达量与转录组数据一致。【结论】本研究在组学水平上证实了蚊虫体壁组织中黑色素的过量累积能够诱导大量表皮蛋白基因的显著上调表达,并使得其表皮结构特征发生改变。研究结果为后续探索黑色素前体对表皮结构基因的调控机制,以及理解昆虫表皮重要组分间的互作模式,对昆虫适应性状的影响提供了新的视角。
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【Aim】To identify gene groups with the most significant changes in the expression in integuments of Anopheles sinensis pupae under melanization-inducing conditions, and explore their correlations with melanin precursor accumulation and cuticular structural features. 【Methods】Grace's insect cell medium was supplemented with the melanin precursors dopa and dopamine. An. sinensis pupal integuments were subjected to in vitro cultivation within the first 20 min of pupation, and a control group(CK) was not treated with melanin precursors. At 16 h after cultivation, pupal integuments from the melanin precursor-treated groups and control group were observed to assess their coloration and cuticular cross-sectional features using a stereomicroscope. The integument transcriptome sequencing of the melanin precursor-treated and control groups was performed using the Illumina platform. GO functional classification and KEGG pathway enrichment analysis were performed on the differentially expressed genes(DEGs). The gene annotations and chromosome distributions of significantly enriched DEGs were analyzed. qRT-PCR was conducted to validate the transcriptome data. 【Results】The integuments and cuticular cross-sections of pupae of An. sinensis treated with dopa and dopamine exhibited noticeable melanization compared with those of CK, and dopa treatment resulted in the deepest pigmentation. The cuticle exhibited significant thickening in the dopa and dopamine treatment groups compared with that of CK, and the degree of thickness was correlated with the degree of melanization. There were 2 952 and 697 DEGs were identified from dopa treatment group vs CK and dopamine treatment group vs CK comparison groups, respectively, and the down-regulated genes predominated. The numbers of the shared up-regulated DEGs and down-regulated DEGs between these two comparison groups were 223 and 347, respectively. GO functional classification result showed that the shared up-regulated DEGs in the above comparison groups and the shared up-regulated DEGs in both comparison groups were significantly enriched to structural constituent of cuticle(GO: 0042302). KEGG pathway enrichment analysis result indicated that the up-regulated DEGs in the dopa treatment group vs CK comparison group were significantly enriched to spliceosome pathway, and the down-regulated DEGs were significantly enriched to Toll-Imd and Hippo signaling pathways. The down-regulated DEGs in the dopamine treatment group vs CK comparison group were significantly enriched to autophagy pathway. No DEGs shared between these two comparison groups were significantly enriched to any pathways. In addition, 65 significantly enriched up-regulated cuticular protein genes belonged to the CPR, CPF, TWDL, CPLC, and CPAP five families and distributed on three chromosomes, and some members were clustered. The expression levels detected by qPCR-PCR for 12 selected shared up-regulated cuticular protein genes in both comparison groups were consistent with the transcriptome data. 【Conclusion】This omics-level study showed that the excessive accumulation of melanin in mosquito pupal integuments led to the significant up-regulation of a large number of cuticular protein genes and changes in cuticular structural features. These findings facilitate subsequent studies of the mechanisms that allow melanin precursors to regulate cuticular structural genes, and to understand the impacts of interactions between important components of the cuticle on the adaptive traits in insects, supplying a new perspective on the impact of insect adaptive traits.
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【目的】本研究旨在鉴定瓜实蝇Zeugodacuscu curbitae雄性决定因子基因MoY上游调控序列,并探索该序列在胚胎早期驱动MoY表达对瓜实蝇性别决定的影响,为后续的瓜实蝇转基因品系的构建提供参考依据以及可用元件。【方法】使用基因组步移法扩增瓜实蝇Y染色体连锁的MoY上游序列并测序,将获得的上游序列连接MoY的CDS区构建其驱动MoY表达的质粒;将MoY表达质粒注射进瓜实蝇新鲜的胚胎中,待胚胎孵化后观察成虫的表型以及性比并提取基因组DNA,通过使用基因组DNA扩增MoY以判断获得的MoY上游调控序列是否具有驱动MoY表达的功能,同时分析MoY在胚胎中的表达对性别决定的影响。【结果】克隆并获得瓜实蝇MoY上游1 660 bp序列,构建该序列驱动MoY表达的质粒p1660。由注射胚胎发育而来的瓜实蝇雄成虫18头和雌成虫13头及另外发现3头成虫的生殖器发育异常且MoY的扩增结果为阴性,确认为间性个体。【结论】本研究通过对MoY进行基因组步移扩增发现所获得的瓜实蝇MoY上游调控序列具有驱动MoY表达的活性,当MoY于瓜实蝇胚胎早期表达可使原本发育为雌性的个体出现性别逆转的现象。
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【Aim】The aim of this study is to identify the upstream regulatory sequence of the male determining factor gene MoY of the melon fly, Zeugodacus cucurbitae, and to explore the impact of this sequence on the sex determination of Z. cucurbitae by directing the expression of MoY in the early embryonic stages, so as to provide a reference basis and available elements for the construction of the subsequent Z. cucurbitae transgenic strains.【Methods】We amplified and sequenced the upstream sequence of MoY linked to the Y chromosome of Z. cucurbitae using the genome-walking, and connected the obtained upstream sequence to the CDS region of MoY to construct a plasmid that drives the expression of MoY. We injected the plasmid expressing MoY into the fresh embryos of Z. cucurbitae, and after hatching, extracted the genomic DNA based on the observed adult phenotype and sex ratio to amplify MoY so as to determine whether the upstream regulatory sequence of MoY had the activity of directing MoY expression and analyze the impact of MoY expression in embryos on the gender determination. 【Results】The upstream sequence of 1 660 bp of MoY of Z. cucurbitae was cloned and obtained, and the plasmid p1660 that drives the MoY expression was constructed. Eighteen male and 13 female adults developed from the injected embryos of Z. cucurbitae, and three adults were found to have abnormal genitalia, with negative amplification results for MoY, confirming them as intersex individuals. 【Conclusion】In this study, we found that the upstream regulatory sequence of MoY of Z. cucurbitae obtained by genome-walking amplification has the activity of directing the expression of MoY. When MoY is expressed in the early stages of Z. cucurbitae embryos, the gender reversal in the previously developed female individuals can be happened.
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【目的】将已获得的中华蜜蜂Apiscerana cerana转录组纳米孔长读段数据比对到东方蜜蜂A. cerana参考基因组,进行注释基因的结构优化,鉴定未注释的新基因和新转录本并进行功能注释以及预测其SSR位点、完整ORF和转录因子(transcription factor, TF)家族及成员的分析验证,完善现有的东方蜜蜂参考基因组序列和功能注释。【方法】基于已获得的高质量的接种蜜蜂球囊菌Ascosphaera apis的中华蜜蜂工蜂4, 5和6日龄幼虫肠道转录组纳米孔测序数据,使用gffcompare软件将已鉴定到的全长转录本比对到东方蜜蜂参考基因组以优化已注释基因的结构;采用gffcompare软件鉴定参考基因组上未注释的新基因和新转录本,再通过比对Nr, KOG, eggNOG, GO和KEGG数据库进行功能注释;使用MISA, TransDecoderv3.0.0和animalTFDB2.0软件分别预测SSR位点、完整ORF和TF家族及成员。【结果】共对东方蜜蜂参考基因组上已注释的4 648个基因结构进行了优化,对1 336个基因同时延长了5'UTR和3'UTR,分别延长了1 688个基因的5'UTR和1 624个基因的3'UTR;共鉴定到2 148个新基因,其中分别有818, 298, 587, 359和333个新基因可注释到Nr, KOG, eggNOG, GO和KEGG数据库;共鉴定到35 432条新转录本,其中分别有30 974, 21 222, 29 025, 19 852和9 214条新转录本可注释到上述5个数据库;共发掘出22 541个SSR位点,其中单、双、三和六碱基重复的SSR数量分别为12 078, 7 140, 2 825和43个,混合SSR的数量为2 964个,分布频率最高的类型是单碱基重复(153.37个/Mb);共预测到58个TF家族及1 611个成员;共预测出28 775个完整ORF,其中编码长度分布在100 ~200个氨基酸的ORF(38.99%)最多。【结论】研究结果优化了东方蜜蜂参考基因组上已注释基因的结构,并补充了参考基因组上未注释的新基因、新转录本、SSR、完整ORF及TF。
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【Aim】 The obtained nanopore long-read data of Apis cerana cerana transcriptome were compared with the reference genome of A.cerana, and the structures of the annotated genes were optimized. The unannotated new genes and new transcripts were identified and functionally annotated, and their SSR loci, complete ORFs and transcription factor(TF) families and members were predicted and verified, so as to improve the sequence and functional annotations of the reference genome of A. cerana. 【Methods】 Based on the high-quality transcriptome nanopore sequencing data of the 4-, 5- and 6-day-old larvae of A. cerana cerana workers infected with Ascosphaera apis, the identified full-length transcripts were mapped to the reference genome of A. cerana with gffcompare software to optimize the structures of the annotated genes. The unannotated novel genes and transcripts in the reference genome were identified utilizing the gffcompare software and mapped to the Nr, KOG, eggNOG, GO and KEGG databases for functional annotation. MISA, TransDecoder v3.0.0 and animalTFDB 2.0 software were employed to respectively predict the SSR loci, complete ORFs as well as TF families and members. 【Results】 A total of 4 648 annotated genes in the reference genome of A. cerana were structurally optimized, the 5'UTR and 3'UTR of 1 336 genes were simultaneously extended, while the 5'UTR of 1 688 genes and the 3'UTR of 1 624 genes were respectively extended. A total of 2 148 novel genes were identified, among which 818, 298, 587, 359 and 333 genes could be annotated to Nr, KOG, eggNOG, GO and KEGG databases, respectively. A total of 35 432 novel transcripts were identified, among which 30 974, 21 222, 29 025, 19 852, and 9 214 could be respectively annotated to the aforementioned five databases. A total of 22 541 SSR loci were detected, of which the numbers of SSRs with single, double, three and six base repeat were 12 078, 7 140, 2 825 and 43, respectively. The number of mixed SSRs was 2 964, and the type with the highest distribution frequency was single base repeat(153.37/Mb), and 58 TF families and 1 611 members were predicted. A total of 28 775 complete ORFs were predicted, of which the ORFs with the coding lengths ranging from 100 to 200 aa(38.99 %) were the most abundant. 【Conclusion】 These results optimize the structures of the annotated genes in the A. cerana reference genome and supplement novel genes, novel transcripts, SSR, complete ORFs, and TFs that were unannotated in the reference genome.
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【目的】探究肠道细菌代谢产物溶血磷脂酸(lysophosphatidic acid, LPA)对蜜蜂摄食行为的影响。【方法】对照组饲喂普通的蔗糖溶液,处理组饲喂含有LPA的蔗糖溶液,构建补充LPA的意大利蜜蜂Apis mellifera ligustica模型,利用群体水平取食测定法和个体水平取食测定法计算意大利蜜蜂6日龄成蜂的取食量,利用食物敏感度测定方法检测LPA对意大利蜜蜂成蜂食物敏感度的影响,最后对意大利蜜蜂成蜂的头、胸、腹和整个个体分别进行重量测定。【结果】 LPA会减少意大利蜜蜂成蜂在群体水平上的取食量,对照组和处理组的群体水平每日平均取食量分别为4.23和2.38 mL。LPA不会影响意大利蜜蜂成蜂在群体水平上对食物的敏感度,也不会影响意大利蜜蜂成蜂在个体水平上对不适口食物的消耗量。分析不同饥饿水平意大利蜜蜂成蜂个体水平食物消耗量发现, LPA会使意大利蜜蜂成蜂个体水平上的饥饿感钝化,即使是饥饿状态下,处理组成蜂的取食量未能达到对照组的正常水平。对比意大利蜜蜂成蜂头、胸、腹和整个个体的重量发现, LPA降低成蜂的食物摄入导致头、胸、腹和整个个体重量显著下降。【结论】蜜蜂肠道细菌的代谢产物LPA会抑制宿主意大利蜜蜂成蜂的食物摄入,进而引起体重下降。
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【Aim】To explore the impact of the gut bacterial metabolite, lysophosphatidic acid(LPA) on food intake behavior in honey bees. 【Methods】 Fed with normal sucrose solution in the control group and sucrose solution containing LPA in the treatment group, a honey bee(Apis mellifera ligustica) model supplemented with LPA was established. The food intake of the 6-day-old adults of A. mellifera ligustica was measured using both group-level feeding assay and individual-level feeding assay. The sensitivity of A. mellifera ligustica adults to food was evaluated using a food sensitivity test. Additionally, the weight of the head, thorax, abdomen and whole individual of A. mellifera ligustica adults was measured.【Results】 LPA reduced the food intake of A. mellifera ligustica adults at the group level. The group-level average daily food intake was 4.23 mL for the control group and 2.38 mL for the treatment group. LPA did not affect the food sensitivity of A. mellifera ligustica adults at the individual level or the intake of unpalatable food. The analysis of food intake at different hunger levels revealed that LPA blunted the hunger sensation in A. mellifera ligustica adults at the individual level. Even in a hungry state, the food intake of A. mellifera ligustica adults in the treatment group failed to reach the normal food intake level observed in the control group. Comparison of the weight of the head, thorax, abdomen, and whole individual of A. mellifera ligustica adults showed a significant decrease in weight due to reduced food intake caused by LPA. 【Conclusion】 LPA, the gut bacterial metabolite, inhibits food intake in the host A. mellifera ligustica adults, leading to a decrease in their body weight.
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【目的】探究芫荽Coriandrum sativum精油对桃蚜Myzus persicae的生物活性和对吡虫啉的增效作用,以及桃蚜对芫荽精油胁迫的响应机制。【方法】分别测定芫荽籽精油和芫荽叶精油对桃蚜成蚜的24 h熏蒸活性(精油浓度为200, 100, 50, 25, 12.5和6.25 μL/mL)和触杀活性(精油浓度为12.5, 6.25, 3.125, 1.563和0.781 μL/mL)半致死浓度(median lethal concentration, LC_(50) )值;配制浓度为4.0, 2.0, 1.0, 0.5和0.25 mg/L的吡虫啉,分别添加体积分数为0.05%的芫荽叶精油和芫荽籽精油,采用浸叶法处理桃蚜成蚜,48 h时检测芫荽叶精油和芫荽籽精油对吡虫啉的增效作用;检测LC_(50)浓度芫荽叶精油和芫荽籽精油触杀处理桃蚜成蚜48 h时保护酶超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(catalase, CAT)和过氧化物酶(peroxidase, POD),解毒酶羧酸酯酶(carboxylesterase, CarE)和谷胱甘肽-S-转移酶(glutathione-S-transferase, GST)及乙酰胆碱酯酶(acetylcholinesterase, AChE)的活性。【结果】芫荽籽精油和芫荽叶精油对桃蚜成蚜的24 h触杀LC_(50)值分别为1.63和3.72 μL/mL,24 h熏蒸LC 50值分别为14.69和34.15 μL/mL。增效试验结果表明,添加体积分数0.05%芫荽籽精油和芫荽叶精油后,吡虫啉对桃蚜成蚜的LC_(50)值分别为0.99和1.51 mg/L,增效比分别为4.78和3.13。与空白对照组相比, LC_(50)浓度芫荽籽精油和芫荽叶精油触杀处理桃蚜成蚜48 h时,保护酶SOD和CAT活性均显著增强,但POD活性没有明显变化;解毒酶CarE和GST及AChE活性均显著增强,其中,芫荽籽精油处理组桃蚜成蚜SOD, GST和AChE活性分别是芫荽叶精油处理组的1.58, 1.20和1.34倍。【结论】芫荽籽精油和芫荽叶精油对桃蚜均具有触杀和熏蒸活性,且均对吡虫啉表现出增效作用,其中芫荽籽精油效果更强;桃蚜可通过升高体内保护酶SOD, CAT活性和解毒酶CarE, GST及AChE活性来应对芫荽精油杀虫成分的胁迫。
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【Aim】The aim is to explore the bioactivity of Coriandrum sativum essential oils against Myzus persicae, and its synergistic effects on imidacloprid, as well as the response mechanism of M. persicae to C. sativum essential oil stress. 【Methods】 The median lethal concentration(LC_(50)) values of 24 h fumigation activity(essential oil concentrations of 200, 100, 50, 25, 12.5, and 6.25 μL/mL) and 24 h contact activity(essential oil concentrations of 12.5, 6.25, 3.125, 1.563, and 0.781 μL/mL) of seed essential oil and leaf essential oil of C. sativum against M. persicae adults were evaluated, respectively. M. persicae adults were treated with imidacloprid solutions at the concentrations of 40, 20, 1.0, 0.5, and 0.25 mg/L containing 0.05% volume fraction of leaf essential oil and seed essential oil of C. sativum, respectively, by leaf-dipping method to determine the synergistic effects of leaf essential oil and seed essential oil of C. sativum on imidacloprid at 48 h after treatment. The activities of the protective enzymes superoxide dismutase(SOD), catalase(CAT) and peroxidase(POD), detoxification enzymes carboxylesterase(CarE) and glutathione-S-transferase(GST), and acetylcholinesterase(AChE) in M. persicae adults at 48 h after contact treatment with LC_(50) concentration of leaf essential oil and seed essential oil of C. sativum were determined. 【Results】 The 24 h contact LC_(50) values of seed essential oil and leaf essential oil of C. sativum against M. persicae adults were 1.63 and 3.72 μL/mL, respectively. The 24 h fumigation LC_(50) values of seed essential oil and leaf essential oil of C. sativum against M. persicae adults were 1469 and 3415 μL/mL, respectively. The synergistic experiment results showed that the LC_(50) values of imidacloprid against M. persicae adults were 0.99 and 1.51 mg/L after adding 0.05% volume fraction of seed and leaf essential oil of C. sativum and the synergistic ratios were 478 and 313, respectively. The activities of the protective enzymes SOD and CAT in M. persicae adults at 48 h after the contact treatment with seed essential oil and leaf essential oil of C. sativum at the LC_(50) concentration were significantly increased, however, those of POD had no significant change as compared with those of the blank control group. The activities of the detoxification enzymes CarE and GST, and AChE in M. persicae adults at 48 h after the contact treatment with seed essential oil and leaf essential oil of C. sativum at LC_(50) concentration were significantly increased as compared with that of the blank control group. The activities of SOD, GST, and AChE in M. persicae adults treated with the C. sativum seed essential oil were 1.58-, 1.20-, and 134-fold as high as those of the treatment group of the C. sativum leaf essential oil, respectively. 【Conclusion】 Seed essential oil and leaf essential oil of C. sativum have contact activity and fumigation activity against M. persicae, and also show synergistic effects on imidacloprid, with seed essential oil displaying stronger effect. M. persicae can respond to the stress of insecticidal components in C. sativum essential oil by increasing the activities of the protective enzymes SOD and CAT, as well as the detoxification enzymes CarE and GST, and AChE.
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【目的】研究大蒜E素(allicin E, ALE)对斑翅果蝇Drosophila suzukii产卵行为的影响,为利用ALE生物防治斑翅果蝇提供参考依据。【方法】采用产卵双向选择模型检测0.01%, 0.015%和0.02% ALE对斑翅果蝇雌成虫产卵驱避作用。利用暗盒实验、摘除前足、摘除触角等方式检测视觉、味觉和嗅觉感觉系统对斑翅果蝇雌成虫产卵偏嗜行为的影响。利用Y生物迷宫试验检测0.015% ALE对斑翅果蝇雌成虫的产卵行为驱避作用。通过检测存活率和发育历期研究ALE对斑翅果蝇适合度的影响。利用荧光染色法检测ALE处理后斑翅果蝇成虫肠道中活性氧水平。【结果】 ALE驱避斑翅果蝇雌成虫产卵,对0.01%, 0.015%和0.02% ALE的产卵指数分别为-0.30, -0.44和-0.51。在黑暗和摘除前足条件下,斑翅果蝇雌成虫存在对ALE的显著的产卵避性反应,而摘除触角的斑翅果蝇对ALE的产卵避性显著降低,对0.01%, 0.015%和0.02% ALE的产卵指数分别降低为-0.10, -0.11和-0.12。斑翅果蝇雌成虫所产卵暴露于0.02% ALE后,后代蛹和成虫的存活率分别降低了69.23%和69.70%,后代成蛹和羽化时间分别延长5.88和4.75 d。 ALE缩短斑翅果蝇成虫寿命,雌性和雄性在0.02% ALE处理下LT50值分别由39 d降低为18和15 d。0.02% ALE处理72 h后斑翅果蝇成虫奔跑和攀爬速度显著降低。0.02%和0.05% ALE处理3 d后斑翅果蝇成虫肠道中的活性氧水平上升。【结论】ALE引起斑翅果蝇雌成虫产卵避性,主要通过嗅觉介导此种产卵避性;ALE延缓了斑翅果蝇后代的生长发育,降低了亲代成虫的运动活力和存活率,并引起肠道损伤,因此具有潜在的生物防治斑翅果蝇价值。
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【Aim】To study the effects of allicin E(ALE) on the oviposition behavior of Drosophila suzukii, and to provide a reference for the biological control of D. suzukii by ALE. 【Methods】The avoidance effects of 0.01%, 0.015% and 0.02% ALE on the oviposition of D. suzukii female adults were detected with oviposition two-choice device. The effects of sensory systems of vision, gustation and olfaction on the oviposition preference of female adults of D. suzukii were investigated by means of darkness, surgically removing the forelegs and antennae, respectively. The avoidance effects of 0.015% ALE on the oviposition behavior of female adults of D. suzukii were tested by Y-maze experiment. The effects of ALE on the fitness of D. suzukii were tested by determining the survival rate and developmental duration. The reactive oxygen species(ROS) level in the intestines of D. suzukii adults treated with ALE was detected by fluorescent staining. 【Results】ALE had avoidance effects on the oviposition of female adults of D. suzukii, and the oviposition indexes to 0.01%, 0.015% and 0.02% ALE were -0.30, -0.44 and -0.51, respectively. In darkness and forelegless groups, the female adults of D. suzukii still showed significant oviposition avoidance to ALE. However, the female adults of D. suzukii with antennae removed had significantly decreased oviposition avoidance to ALE, and the oviposition indexes to 001%, 0.015% and 0.02% ALE were decreased to -0.10, -0.11 and -0.12, respectively. After the eggs laid by female adults of D. suzukii were exposed to 0.02% ALE, the offspring pupal and adult survival rates were decreased by 69.23% and 69.70%, respectively, and the time to puparium formation and time to adult eclosion of offspring were prolonged by 5.88 and 4.75 d, respectively. ALE shortened the adult life span of D. suzukii, and the LT50 values of females and males under 0.02% ALE treatment decreased from 39 d to 18 and 15 d, respectively. The running and climbing speeds of D. suzukii adults were significantly decreased at 72 h after treatment with 0.02% ALE. The ROS levels in the intestine of D. suzukii adults were increased at 3 d after treatment with 0.02% and 0.05% ALE. 【Conclusion】ALE induces oviposition avoidance in female adults of D. suzukii, which is mediated mainly by olfaction. ALE prolongs the growth and development of the offspring of D. suzukii, decreases the locomotion performance and the survival rate of adults, and causes intestine damage in adults, thereby having potential biological control value against D. suzukii.
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【目的】探究松墨天牛Monochamus alternatus雌成虫卵巢发育过程,从日龄的角度对松墨天牛卵巢发育进行分级,并且判断引诱剂野外诱捕雌成虫的发育状态,为松墨天牛高效防控提供参考。【方法】对达到0, 5, 10, 15, 20, 30, 40和15日龄交配前后的松墨天牛雌成虫以及引诱剂诱集雌成虫进行生物解剖,观察卵巢发育状态。【结果】松墨天牛雌成虫卵巢发育过程分为5级:发育前期(0 -5日龄):卵巢管透明纤细,无卵黄沉积;卵黄沉淀期(5 -15日龄):卵巢管内含有少数乳白色和淡黄色未成熟的卵粒;卵巢成熟期(15 -20日龄):卵巢管内包含大量完全成熟的卵粒,呈长纺锤形,黄色饱满有光泽;产卵盛期(20 -40日龄):输卵管萼中堆满成熟卵粒,中输卵管和侧输卵管中存在待产的卵粒;衰老期(≥40日龄):卵巢管、输卵管萼和输卵管逐渐萎缩。交配后的雌成虫能够产生受精卵,输卵管萼膨大、形态清晰;未交配的雌成虫无法产生受精卵,卵粒堆积在输卵管中无法产出,输卵管萼未分化完全、形态不清晰。野外诱集结果显示,诱集的不同日龄的雌成虫量具有显著性差异,其中处于产卵盛期的雌成虫占比最多,占总量的54.90% ±5.50%;卵巢成熟期、衰老期和卵黄沉淀期的雌成虫占比较少,分别占总量的31.37% ±5.52%, 11.76% ±1.54%和1.96% ±0.51%;没有诱集到发育前期的雌成虫。【结论】松墨天牛雌成虫发育至15 -20日龄达到性成熟;交配行为能够促进松墨天牛雌成虫卵巢发育。引诱剂可以诱捕到大量刚性成熟的松墨天牛成虫,对于减少松墨天牛产卵量,降低下一代发生基数,降低松材线虫Bursaphelenchus xylophilus传播几率具有积极意义。
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【Aim】 To investigate the ovarian developmental process of female adults of Monochamus alternatus, categorize the ovarian development of M. alternatus from the perspective of age, and judge the developmental status of female adults trapped by attractants in the field, so as to provide a reference for effective prevention and control of M. alternatus. 【Methods】 The mated and unmated female adults of M. alternatus at the 0-, 5-, 10-, 15-, 20-, 30-, 40- and 15-day-old, and the female adults trapped by attractants were dissected to observe the ovarian development. 【Results】 The ovarian developmental process of female adults of M. alternatus can be divided into five stages: prophase(0-5-day-old): the ovariole is transparent and slender, and there is no egg yolk deposition;egg yolk precipitation stage(5-15-day-old): there are a few milky white and yellowish immature eggs in the ovariole;ovarian maturity stage(15-20-day-old): ovariole contains a large number of fully mature eggs, which are long spindle-shaped, yellow and full of luster;oviposition peak stage(20-40-day-old): mature eggs are piled up in the egg calyx, and there are eggs to be laid in the median oviduct and lateral oviduct;and aging stage(≥40-day-old): ovariole, egg calyx and oviduct gradually atrophy. After mating, the female adults can produce fertilized eggs, and the egg calyx is enlarged and visible. The unmated females can't produce fertilized eggs, and the eggs can't be produced when they are accumulated in the oviduct, and the egg calyx is not fully differentiated and the shape is invisible. The results of field trapping showed that there were significant differences in the number of trapped female adults at different day-old ages, and the proportion of the female adults in the oviposition peak stage was the most, accounting for 5490%±550% of the total. The female adults at the ovarian maturity stage, aging stage and egg yolk precipitation stage were relatively few, accounting for 31.37%±5.52%, 11.76%±1.54% and 1.96%±0.51% of the total, respectively. No female adults at the prophase were lured. 【Conclusion】 Female adults of M. alternatus develop to sexual maturity at the 15-20-day-old age, and mating behavior can promote the ovarian development of female adults of M. alternatus. Attractants can trap a large number of rigid mature M. alternatus, which is of positive significance for reducing the oviposition of M. alternatus, the occurrence base of the next generation and the transmission probability of Bursaphelenchus xylophilus.
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【目的】为了更好地利用性信息素进行番茄潜叶蛾Tuta absoluta的测报和防控,深入研究其运动、求偶和交配行为的昼夜节律。【方法】针对番茄潜叶蛾成虫,采用视频记录和二维轨迹分析其运动;固相微萃取(solid-phase microextraction, SPME)吸附提取和气相色谱-质谱联用(gas chromatography-mass spectrometry, GC-MS)分析雌成虫性信息素滴度;2022年8 -9月在四川省西昌市番茄大棚开展番茄潜叶蛾田间诱捕试验,根据诱捕结果分析番茄潜叶蛾成虫性信息素滴度与日龄和昼夜节律的关系,室内养虫笼内观察交配行为,并抽样解剖观察分析番茄潜叶蛾雄成虫的生殖系统发育与日龄关系。【结果】结果表明,在室内环境下,雌雄成虫的运动发生在暗期第5小时开始至光期第2小时结束,但进入暗期第5 -7小时为高峰期,其运动时间和距离在雌雄及所测日龄(1 -7日龄)之间均没有显著差异。番茄潜叶蛾的性信息素在1 -11日龄成虫中都能检测到,日龄之间性信息素滴度没有显著差异。雌成虫性信息素在整个24 h内都可检测到,且不同时段之间信息素滴度差异不显著。交配没有显著影响雌成虫性信息素滴度。田间雄成虫被诱捕到的时间段在暗期第7小时至光期第2小时。番茄潜叶蛾成虫羽化当天就可以交配,交配率在3日龄为最高,之后则下降,交配持续时间在日龄之间没有显著差异。交配的高峰期则发生在暗期第7和10小时,进入光期之后则无新增的交配。雄成虫精巢体积随着日龄的增加而减少,依据性诱雄成虫的体积大小推算其日龄在3 -7日龄。【结论】番茄潜叶蛾成虫的求偶和交配时间发生在暗期的末段,雌成虫性信息素滴度在不同日龄和昼夜节律保持持续的高水平,交配也不影响性信息素滴度。性诱雄成虫的年龄偏大,其精巢体积与7日龄的一致,多数可能已经交配。研究结果为不仅深入了解了番茄潜叶蛾成虫的求偶和交配行为,而且为开发基于性信息素的防控技术提供依据。
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【Aim】To make better use of sex pheromones in the monitoring and control of the tomato leafminer, Tuta absoluta, and to further study the circadian rhythms of its movement, calling and mating behavior. 【Methods】For T. absoluta adults, video recording and two-dimensional trajectories were used to analyze their movements. Solid-phase microextraction(SPME) adsorption extraction and gas chromatography-mass spectrometry(GC-MS) were used to analyze the sex pheromone titer in female adults. In tomato greenhouses in Xichang City, Sichuan Province from August to September 2022, field trapping experiments were carried out to analyze the relationship between the sex pheromone titers of T. absoluta adults and their day-old age and circadian rhythm based on the trapping results. The mating behavior was observed in indoor insect cages, and the reproductive system of the male adult was observed by dissection, and the relationship between development and day-old age was analyzed. 【Results】The results showed that in the indoor natural environment, the movement of female and male adults occurred from the 5th hour of the scotophase to the 2nd hour of the photophase, with the peak at the 5th to 7th hour of the scotophase, and there was no significant difference in the time and distance of movement between females and males, and between the 1-7-day-old assayed. The sex pheromones of T. absoluta can be detected in adults at the 1-11-day-old, but there was no significant difference in the sex pheromone titer between day-old ages. The sex pheromones released by female adults were detected during the entire 24 h period, and the difference in the sex pheromone titer between different periods was not significant. Mating did not significantly affect the sex pheromone titer in female adults. However, the male adults in the field were trapped from the 7th hour of the scotophase to the 2nd hour of the photophase. T. absoluta adults were able to mate on the same day of emergence, and the mating rate was the highest when the male adults were at the 3-day-old, and then decreased, but there was no significant difference in the mating duration between day-old ages. The peak time of mating occurred at the 7th and 10th hour of the scotophase, and there was no new mating after the photophase. The testicular volume of male adults decreased as the day-old age increased, and based on the testicular volume of male adults caught by sex pheromone trapping, it was calculated that the age of those trapped males was 3-7-day-old. 【Conclusion】The calling and mating time of T. absoluta adults occurred at the end period of the scotophase. The sex pheromone titer of female adults remained at a consistently high level at different day-old ages and circadian rhythms, and mating did not significantly affect sex pheromone titer, resulting in older male adults being caught by pheromone trapping, and their testes were the same size as those of the 7-day-old male adults, and most of them may have already mated. The data here give a more clear description of the calling and mating behavior of T. absoluta adults, thus, they can provide technical bases and parameters for the development and application of mass trapping and mating disruption by sex pheromones.
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媒介昆虫可传播寄生虫和病毒,如疟原虫、寨卡病毒和登革热病毒等,每年在全球范围内造成重大的经济损失与人员伤亡。农业害虫则每年造成农作物产量的重大损失,严重威胁着全球粮食安全。然而,目前基于化学防治等手段已不足以完全控制害虫的发生与危害。同时,使用化学农药会导致抗性产生,造成环境污染和农药残留等。因此,生产上亟需开发新型害虫控制策略。近年来,随着基因组测序技术和基因编辑技术的发展,针对目标害虫种群及其特定靶标基因的遗传控制技术迅速发展。相比传统的有害生物防控手段如化学防治等,害虫遗传控制策略具有物种特异性、环境友好和防控高效等优势。本文主要综述了研究较为广泛的几种害虫遗传控制技术,包括昆虫不育技术(sterile insect technique, SIT)、昆虫显性致死释放(release of insects carrying a dominant lethal, RIDL)技术以及基因驱动(genedrive, GD)技术等的研究现状与应用案例。最后,我们对害虫遗传控制技术研究及其在农业害虫防治中的应用做出了几点展望:(1)建立稳定高效的遗传操作体系;(2)鉴定生殖细胞或其他组织中高效的启动子,以提高基因编辑或基因转化的效率;(3)解析害虫性别决定通路和挖掘参与害虫生殖发育的关键基因。
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Insect vectors cause significant economic losses and human casualties worldwide each year by transmitting parasites and viruses such as malaria, Zika virus, and dengue. Agricultural pests cause huge losses of crop yield every year and seriously threaten global food security. However, the current control methods based on chemical agents are insufficient to completely control the occurrence and damage of pests. At the same time, the use of chemical pesticides will induce resistance and result in environmental pollution and pesticide residues, etc. Therefore, there is an urgent need to develop new pest control strategies in production. In recent years, with the development of genome sequencing and gene editing techniques, the genetic control technology for the target pest population and their specific target genes has been rapidly developed. Compared with traditional pest control methods such as chemical control, genetic control strategies for pests have the advantages of species specificity, environmental friendliness, and efficient control. In this article, we reviewed several widely studied genetic control techniques for pests, including sterile insect technique(SIT), release of insects carrying a dominant lethal(RIDL), and gene drive(GD) technology. Finally, we presented several prospects for the research of genetic control technology for pests and its application in agricultural pest control:(1) to establish stable and efficient genetic manipulation systems;(2) to identify efficient promoters in germ cells or other tissues to improve the efficiency of gene editing or gene transformation;and(3) to elucidate the sex determination pathway of pests and excavate the key genes involved in the reproductive development of pests.
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近60年来,熏蒸剂磷化氢被广泛用于储藏物害虫的防治。但是,长期、不合理地使用磷化氢,导致储藏物害虫抗药性的广泛产生。了解磷化氢的毒理机制可以为磷化氢抗性机制研究提供思路。早期的研究发现,磷化氢通过干扰神经传导、抑制能量代谢和破坏氧化还原系统,引起害虫死亡;但近年的研究表明,磷化氢致死害虫的主要机制是抑制能量生成和通过干扰氧化还原系统来增加氧化损伤。早期的研究发现,害虫对磷化氢的抗性机制主要包括主动排斥磷化氢、保护性昏迷和增强解毒酶活性。近年来,随着基因组学、蛋白组学和代谢组学的应用,相继出现一些新的磷化氢抗性机制,如穿透抗性、磷化氢作用靶标敏感性降低、能量代谢模式调整。越来越多的研究表明,靶标二氢硫辛酰胺脱氢酶突变以及抗氧化酶和解毒酶活性增强是主要的抗性机制,而能量代谢模式调整可能是抗性形成初期抵抗磷化氢不良影响的重要机制。采用基因渐渗的方法研究害虫磷化氢抗性突变的适合度代价可以更精准地预测抗性突变的进化方向。研究害虫的磷化氢抗性机制和抗性突变的进化潜力不仅有助于理解害虫抗药性的形成和生物的进化,同时对害虫的磷化氢抗性监测和治理有重要的意义。
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The fumigant phosphine has been widely used in protecting stored products against insect pests for over 60 years. However, the long-term and improper application of phosphine has led to extensive phosphine resistance among stored product pests. Knowledge of the mechanisms of phosphine toxicology can provide ideas for the study of the mechanisms of phosphine resistance. Although it has been accepted that phosphine causes death of insect pests by disruption of the nerve conduction, suppression of energy metabolism, and destruction of the redox system, recent studies have revealed that the main lethal mechanisms involve inhibiting the energy production, and disturbing redox system to increase oxidative damage. Earlier studies demonstrated that the mechanisms of phosphine resistance mainly included active exclusion of phosphine, protective narcosis, and upregulation of detoxification enzyme activities. In recent years, with the application of genomics, proteomics, and metabolomics, some novel resistance mechanisms, such as penetration resistance, decreased sensitivity of the target of phosphine, and reprogrammed energy metabolism, have been proposed. Increasing researches supported that strong phosphine resistance should be mainly attributed to mutations of the target dihydrolipoamide dehydrogenase and upregulation of antioxidase and detoxification enzyme activities, while reprogrammed energy metabolism is a possible strategy adopted to counteract the negative influence of phosphine during the early stage of resistance formation. Application of gene introgression in the study of fitness costs associated with phosphine resistance mutations facilitates precisely predicting the evolution direction of resistance mutations. Knowledge of the mechanisms of phosphine resistance and the evolutionary potential of resistance mutations not only helps understand pesticide resistance development and biological evolution, but also provides insights into the monitoring and management of phosphine resistance.
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【目的】探究褐飞虱Nilaparvata lugens如何适应抗性水稻品种YHY15,并为研究环状RNA(circularRNA, circRNA)在褐飞虱对抗性水稻适应机制中的作用奠定基础。【方法】利用高通量测序技术鉴定生物型1和生物型Y(能致害抗性水稻YHY15的生物型)褐飞虱的circRNA,并统计其类型和分布。分析生物型1和生物型Y褐飞虱间circRNA表达差异,并对circRNA来源基因进行GO功能注释和KEGG富集分析。【结果】生物型1和生物型Y褐飞虱共鉴定到19个circRNA,分布在9条染色体上,其中17个circRNA由剪接位点之间的外显子构成,2个circRNA由剪接位点之间的所有碱基构成,17个circRNA长度在200 ~800 bp。生物型Y褐飞虱的circRNA表达丰度与表达量比生物型1褐飞虱的更高。分析结果表明,在生物型1褐飞虱克服抗性水稻YHY15形成新的生物型Y的过程中,在自然选择压力下,circRNA的表达出现变化,推测这种变化影响了褐飞虱新生物型的形成。KEGG分析结果表明,鉴定到的生物型1和生物型Y褐飞虱circRNA来源基因主要富集到自噬相关通路上。【结论】褐飞虱长期取食抗性水稻,导致褐飞虱消化、解毒和代谢能力进化,能降解抗性水稻为抵御褐飞虱而产生的次生代谢物。鉴定到的生物型1和生物型Y褐飞虱的circRNA来源基因与细胞自噬相关,表明褐飞虱通过细胞自噬过程应答抗虫水稻,这种应答反应促进褐飞虱适应抗虫水稻,致害性增强和生物型形成。
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【Aim】 To explore how the brown planthopper(Nilaparvata lugens) adapts to the resistant rice variety YHY15 and lay a foundation for studying the role of circular RNA(circRNA) in the adaptation mechanism of N. lugens to resistant rice. 【Methods】 The circRNAs of biotype 1 and biotype Y(biotype that can cause damage to resistant rice YHY15) of N. lugens were identified by high-throughput sequencing technology, and the type and distribution of circRNAs were counted. The expression differences of circRNAs between biotype 1 and biotype Y of N. lugens were analyzed, and GO functional annotation and KEGG enrichment analysis of the circRNA source genes were performed. 【Results】 A total of 19 circRNAs were identified in biotype 1 and biotype Y of N. lugens, and distributed on nine chromosomes. Among them, 17 circRNAs were composed of exons between splicing sites, two circRNAs were composed of all bases between splicing sites, and 17 circRNAs were 200-800 bp in length. The expression abundance and expression level of circRNAs in biotype Y of N. lugens were higher than those in biotype 1 of N. lugens. The analysis results showed that in the process of biotype 1 of N. lugens overcoming the resistance of rice YHY15 to form a new biotype Y of N. lugens, under the pressure of natural selection, the expression of circRNA changed resulting in the effects on the formation of a new biotype of N. lugens. The KEGG analysis results indicated that the identified circRNA source genes of biotype 1 and biotype Y of N. lugens were mainly enriched in autophagy-related pathways. 【Conclusion】 Long-term feeding of resistant rice by N. lugens leads to the evolution of the digestion, detoxification, and metabolic abilities of N. lugens, which can degrade the secondary metabolites produced by resistant rice to resist N. lugens. The circRNA source genes of biotype 1 and biotype Y of N. lugens are enriched in autophagy-related pathways, indicating that N. lugens respond to insect-resistant rice through the process of autophagy. This response promotes the adaptation of N. lugens to insect-resistant rice, enhances pathogenicity, and forms biotypes.
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传统药方小陷胸汤及其加减化裁方可用于新型冠状病毒肺炎的临床治疗,但其抗炎有效成分及作用机制尚不清楚.首先通过网络药理学筛选小陷胸汤的活性成分,其次在细胞水平上探究其对免疫细胞的调控效果,最后从分子水平验证其治疗新冠肺炎的可能性.实验结果表明:小陷胸汤治疗新冠肺炎可能是通过槲皮素、黄芩素、β-谷甾醇、香叶木素等活性成分调节CD4~+ T细胞以及CD4~+/CD8~+比值,起到抗炎、调节自身免疫反应的作用.黄芩素很可能通过与新冠病毒关键蛋白3CLpro(Mpro)的关键位点结合,从而抑制3CLpro的复制功能,进而达到抗病毒的作用.槲皮素可能通过提高调节性T细胞分化程度降低肺部炎症情况.香叶木素可通过改变巨噬细胞分化情况以及提升NK细胞比例来增强机体固有免疫,起到治疗肺炎的作用.
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As a traditional prescription, Xiaoxianxiong Decoction and its verified prescriptions are used in the clinical treatment for COVID19(Corona Virus Disease 2019). Though it has broad practical basis, the mechanism of its anti-inflammatory active ingredients is still unobscured. Along with the development of genomics and proteomics, massive amounts of bioinformatics data can be used to analyze the mechanism of drug-disease in the protein, molecular, and genetic levels. Active ingredients of Xiaoxianxiong Decoction were screened through network pharmacology, its regulatory effect on immune cells was explored, and its possibility of treating COVID-19 at the molecular level was further verified. The results showed that main activated components of Xiaoxianxiong Decoction to treat COVID-19 were quercetin, baicalein, β-sitosterol, diosmetin. Those active ingredients could up-regulate level of CD4~+ T cells and the ratio of CD4~+/CD8~+ to regulate excessiveimmune response. The study also suggested that Baicalein could inhibit the replication function of 3CLpro by binding to the critical site of 3CLpro, an essential protein of the new coronavirus, and achieving antiviral effect. Quercetin could reduce lung inflammation by improving the differentiation of regulatory T cells. Diosmetin could enhance human innate immunity by regulating the differentiation of macrophages and increasing the proportion of NK cells, thus playing a role in the treatment of COVID-19.
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霍乱弧菌(Vibrio cholera)作为弧菌科的主要致病菌,是人类霍乱的病原体,它可以引起烈性肠道传染病,给人们的生命造成了巨大的威胁.多聚磷酸polyP广泛分布于细菌体内,在细菌的运动性、细胞膜的形成、严紧反应等过程中发挥关键作用,而外切聚磷酸酶PPX是水解polyP的主要蛋白,可直接影响细菌的致病性.本研究利用大肠杆菌原核表达的方法成功获得可溶性霍乱弧菌PPX蛋白,经过多种方式的纯化、结晶条件的筛选和优化得到蛋白晶体.通过X射线衍射实验收集到0.24 nm的衍射数据,使用HKL 2000软件对衍射数据进行了处理,这些数据为PPX晶体结构的解析奠定基础.
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As the main pathogen of Vibrio, is the pathogen of human cholera, which can cause severe intestinal infectious diseases and pose a great threat to people's lives. PolyP is widely distributed in bacteria, which plays a key role in the process of bacterial motility, cell membrane formation, and stringent reaction. Exopolyphosphatase PPX is the main protein hydrolyzing polyP, which can directly affect the pathogenicity of bacteria.In this study, the soluble PPX protein was successfully obtained by prokaryotic expression of Escherichia coli, and the protein crystals were obtained by screening and optimizing the crystallization conditions through various methods. Diffraction data of 0.24 nm were collected by X-ray diffraction experiments, and the diffraction data were processed using HKL2000. These data laid the foundation for the analysis of PPX crystal structure.
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