1. Introduction The convexity of surfaces is an interesting mathematical topic with application to modeling objects (for example, optical lenses). Conditions for Bernstein-Bézier surfaces defined over triangles t...1. Introduction The convexity of surfaces is an interesting mathematical topic with application to modeling objects (for example, optical lenses). Conditions for Bernstein-Bézier surfaces defined over triangles to be convex have recently been developed in [1][4][5][6].展开更多
The African clawed frog, Xenopus laevis, has long been a model animal for the studies in the fields of animal cloning, developmental biology, biochemistry, cell biology, and physiology. With the aid of Xenopus, major ...The African clawed frog, Xenopus laevis, has long been a model animal for the studies in the fields of animal cloning, developmental biology, biochemistry, cell biology, and physiology. With the aid of Xenopus, major molecular mechanisms that are involved in embryonic development have been understood. Germ layer formation is the first event of embryonic cellular differentiation, which is induced by a few key maternal factors and subsequently by zygotic signals. Meanwhile, another type of signals, the pluripotency factors in ES cells, which maintain the undifferentiated state, are also present during early embryonic cells. In this review, the functions of the pluripotency factors during Xenopus germ layer formation and the regulatory relationship between the signals that promote differentiation and pluripotency factors are discussed.展开更多
文摘1. Introduction The convexity of surfaces is an interesting mathematical topic with application to modeling objects (for example, optical lenses). Conditions for Bernstein-Bézier surfaces defined over triangles to be convex have recently been developed in [1][4][5][6].
基金supported by the National Basic Research Program of China(2011CB943804,2014CB964701)the National Natural Science Foundation of China(31271544,31261160492)to Cao Ying
文摘The African clawed frog, Xenopus laevis, has long been a model animal for the studies in the fields of animal cloning, developmental biology, biochemistry, cell biology, and physiology. With the aid of Xenopus, major molecular mechanisms that are involved in embryonic development have been understood. Germ layer formation is the first event of embryonic cellular differentiation, which is induced by a few key maternal factors and subsequently by zygotic signals. Meanwhile, another type of signals, the pluripotency factors in ES cells, which maintain the undifferentiated state, are also present during early embryonic cells. In this review, the functions of the pluripotency factors during Xenopus germ layer formation and the regulatory relationship between the signals that promote differentiation and pluripotency factors are discussed.
