[Objective] The aim was to optimize Yanbian cow oocytes mature in vitro and cleavage system after nuclear transfer based on uniform design. [Method] Oocytes were recovered by aspiration method, and oocytes were mature...[Objective] The aim was to optimize Yanbian cow oocytes mature in vitro and cleavage system after nuclear transfer based on uniform design. [Method] Oocytes were recovered by aspiration method, and oocytes were matured in vitro （IVM） with different conditions, and then carried out nucleus transfer, fusion, activation and in vitro culture （IVC） of embryo. Effects of ovary storage temperature, maturation time and follicular diameter size on in vitro maturation and cleavage rates of cow oocytes were compared. [ Result] The best conditions of IVM of Yanbian cow oocytes was that： the oocytes of 8 mm diameter were matured in vitro for 24 hours when the ovaries were stored at 26℃ or 31 ℃. The best cleave conditions after nucleus transfer of oocytes was that： the oocytes of 6 mm or 8 mm diameter were cultured in vitro for 24 hours when the ovaries were stored at 26℃. [ Conclusion] The result has some reference to Yanbian cow and other cow breeding and population expanding propagation.展开更多
Recent developments in nanochemistry offer precise morphology control of nanomaterials, which has significant impacts in the field of heterogeneous catalysis. Rational design of bifunctional catalysts can influence va...Recent developments in nanochemistry offer precise morphology control of nanomaterials, which has significant impacts in the field of heterogeneous catalysis. Rational design of bifunctional catalysts can influence various aspects of catalytic properties. In this review, a new class of bifunctional catalysts with a metal@silica yolk-shell nanostructure is introduced. This structure has many advantages as a heterogeneous catalyst since it ensures a homogeneous environment around each metal core, and particle sintering is effectively eliminated during high temperature reactions. The catalysts exhibit high activity and recyclability in gas- and solution-phase reactions. It is anticipated that appropriate selection of bifunctional components and optimal structural control will significantly further enhance the catalytic properties, and enable target reaction-oriented development of new catalysts.展开更多
文摘[Objective] The aim was to optimize Yanbian cow oocytes mature in vitro and cleavage system after nuclear transfer based on uniform design. [Method] Oocytes were recovered by aspiration method, and oocytes were matured in vitro （IVM） with different conditions, and then carried out nucleus transfer, fusion, activation and in vitro culture （IVC） of embryo. Effects of ovary storage temperature, maturation time and follicular diameter size on in vitro maturation and cleavage rates of cow oocytes were compared. [ Result] The best conditions of IVM of Yanbian cow oocytes was that： the oocytes of 8 mm diameter were matured in vitro for 24 hours when the ovaries were stored at 26℃ or 31 ℃. The best cleave conditions after nucleus transfer of oocytes was that： the oocytes of 6 mm or 8 mm diameter were cultured in vitro for 24 hours when the ovaries were stored at 26℃. [ Conclusion] The result has some reference to Yanbian cow and other cow breeding and population expanding propagation.
文摘Recent developments in nanochemistry offer precise morphology control of nanomaterials, which has significant impacts in the field of heterogeneous catalysis. Rational design of bifunctional catalysts can influence various aspects of catalytic properties. In this review, a new class of bifunctional catalysts with a metal@silica yolk-shell nanostructure is introduced. This structure has many advantages as a heterogeneous catalyst since it ensures a homogeneous environment around each metal core, and particle sintering is effectively eliminated during high temperature reactions. The catalysts exhibit high activity and recyclability in gas- and solution-phase reactions. It is anticipated that appropriate selection of bifunctional components and optimal structural control will significantly further enhance the catalytic properties, and enable target reaction-oriented development of new catalysts.
