  In present work the conductivity in the basis plane of YBaCuO single crystals
slightly doped by Al and Pr with a pre-specified topology of twin boundaries
has been investigated. The excess conductivity for the analyzed samples shows
dependence like $\Delta\sigma\sim(1-T/T^*)\exp(\Delta_{ab}^*/T)$ in wide
temperature range $T_f<T<T^*$, where $T^*$ can be represents as mean field
temperature of superconducting transition. The temperature dependence of
pseudogap can be satisfactory described in terms of the BCS-BEC crossover
theoretical model.
