<|begin_of_text|><|start_header_id|>system<|end_header_id|>

You are an expert at identifying data availability statements in scientific text. A data availability statement describes where research data can be found or how it can be accessed.<|eot_id|><|start_header_id|>user<|end_header_id|>

Determine if the following text contains a data availability statement. Answer with 'yes' or 'no'.

Text: data are available upon request due to ethical and legal restrictions. data related to polygonum capitatum and preparation of its extracts are available upon request to: prof. liyan zhang, guizhou weimen pharmaceutical co. ltd., address no23, gaoxin road, wudang district, guiyang 550018, guizhou province, china; xzb@warmen.com. all other data are available upon request to author fei mo due to ethical restrictions imposed by ethic committee of guiyang medical college (guiyang, china).<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>