The microstructures and growth process characteristics precipitation-crystallization method were investigated by SEM, TEM of spherical Ni（OH）2 particles synthesized by the aqueous and XRD, and their growth mechanism...The microstructures and growth process characteristics precipitation-crystallization method were investigated by SEM, TEM of spherical Ni（OH）2 particles synthesized by the aqueous and XRD, and their growth mechanism was discussed. With the reaction beginning and continuing, amorphous Ni（OH）2 nano-crystallites grow up to spherical micron-particles with radially arranged crystallites. The nucleation, crystallization and re-crystallization led by Ostwald ripening simultaneously take place through the whole growth processes. With the course from reversible aggregation to irreversible agglomeration, the Ni（OH）2 particles tend to grow according to the template growth model： the growth on the crystallite templates stretching in the radius directions is free and quick, while the growth rate for crystallites in other directions is confined due to lower monomers concentration and tends to dissolve So it is only the radially arranged crystallites that predominate in the particle and lead to characteristic microstructures.展开更多
The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures （nucleoplasm, chromatin, nuclear ...The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures （nucleoplasm, chromatin, nuclear matrix） as possible zones affecting the conformational rearrangements of the total interphase chromatin at the induction of increasing morphogenesis of mature embryos-germs of spring and transformed from its winter wheat. Germinated embryos-germs were detached from endosperm after 24 hours from the start of soaking. Cell nuclei have been allocated from embryos-germs and cleared, and then from their heteropolymer suprastructures （nucleoplasm, chromatin loosely bound with nuclear matrix and chromatin tightly bound with nuclear matrix, and nuclear matrix） were extracted by increasing ionic strength of solution. From isolated nuclear suprastructures, non-histone proteins were separated from histones using ion exchange chromatography. Trypsin-like complexes from non-histone proteins and histone blocks were isolated using the affinity chromatography. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine. Hypersensitivity to the Arg-X proteolysis in trypsin-like complexes detected at the level suprastructures of chromatin tightly bound with the nuclear matrix was shown. The most active changes of the nuclear proteome have occurred at the level of the non-histone proteins and the core histones （H2A ＋ H2B） （H3 ＋ H4） of induced to growth embryos-seedlings of winter wheat （compared to the initial spring form of wheat）. Perhaps hypersensitivity to the Arg-X activity of the trypsin-like complexes in the non-histone proteins and the core blocks of chromatin tightly bound with nuclear matrix have been entrenched during the transforming of the winter wheat from the initial spring wheat.展开更多
In vitro maturation(IVM), the maturation in culture of immature oocytes, has been used in clinic for more than 20 years.Although IVM has the specific advantages of low cost and minor side effects over controlled ovari...In vitro maturation(IVM), the maturation in culture of immature oocytes, has been used in clinic for more than 20 years.Although IVM has the specific advantages of low cost and minor side effects over controlled ovarian stimulation, the prevalence of IVM is less than 1% of routine in vitro fertilization and embryo transfer techniques in many reproductive centers. In this review, we searched the MEDLINE database for all full texts and/or abstract articles published in English with content related to oocyte IVM mainly between 2000 and 2016. Many different aspects of the IVM method may influence oocyte potential,including priming, gonadotrophin, growth factors, and culture times. The culture conditions of IVM result in alterations in the oocyte or cumulus cell transcriptome that are not observed under in vivo culture conditions. Additionally, epigenetic modifications, such as DNA methylation or acetylation, are also different between in vitro and in vivo cultured oocytes. In sum,current IVM technique is still not popular and requires more systematic and intensive research to improve its effects and applications. This review will help point our problems, supply evidence or clues for future improving IVM technique, thus assist patients for fertility treatment or preservation as an additional option.展开更多
基金Project(50134020) supported by the National Natural Science Foundation of ChinaProject supported by Postdoctoral Fund of Central South University
文摘The microstructures and growth process characteristics precipitation-crystallization method were investigated by SEM, TEM of spherical Ni（OH）2 particles synthesized by the aqueous and XRD, and their growth mechanism was discussed. With the reaction beginning and continuing, amorphous Ni（OH）2 nano-crystallites grow up to spherical micron-particles with radially arranged crystallites. The nucleation, crystallization and re-crystallization led by Ostwald ripening simultaneously take place through the whole growth processes. With the course from reversible aggregation to irreversible agglomeration, the Ni（OH）2 particles tend to grow according to the template growth model： the growth on the crystallite templates stretching in the radius directions is free and quick, while the growth rate for crystallites in other directions is confined due to lower monomers concentration and tends to dissolve So it is only the radially arranged crystallites that predominate in the particle and lead to characteristic microstructures.
文摘The purpose of this study was to analyze spatio-temporal dynamics of localization of protease-sensitive sites Arg-X in non-histone and histone blocks of heteropolymer suprastructures （nucleoplasm, chromatin, nuclear matrix） as possible zones affecting the conformational rearrangements of the total interphase chromatin at the induction of increasing morphogenesis of mature embryos-germs of spring and transformed from its winter wheat. Germinated embryos-germs were detached from endosperm after 24 hours from the start of soaking. Cell nuclei have been allocated from embryos-germs and cleared, and then from their heteropolymer suprastructures （nucleoplasm, chromatin loosely bound with nuclear matrix and chromatin tightly bound with nuclear matrix, and nuclear matrix） were extracted by increasing ionic strength of solution. From isolated nuclear suprastructures, non-histone proteins were separated from histones using ion exchange chromatography. Trypsin-like complexes from non-histone proteins and histone blocks were isolated using the affinity chromatography. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine. Hypersensitivity to the Arg-X proteolysis in trypsin-like complexes detected at the level suprastructures of chromatin tightly bound with the nuclear matrix was shown. The most active changes of the nuclear proteome have occurred at the level of the non-histone proteins and the core histones （H2A ＋ H2B） （H3 ＋ H4） of induced to growth embryos-seedlings of winter wheat （compared to the initial spring form of wheat）. Perhaps hypersensitivity to the Arg-X activity of the trypsin-like complexes in the non-histone proteins and the core blocks of chromatin tightly bound with nuclear matrix have been entrenched during the transforming of the winter wheat from the initial spring wheat.
基金supported by the National Natural Science Foundation of China(81300456)the Joint Research Fund for Overseas Natural Science of China(31429004)
文摘In vitro maturation(IVM), the maturation in culture of immature oocytes, has been used in clinic for more than 20 years.Although IVM has the specific advantages of low cost and minor side effects over controlled ovarian stimulation, the prevalence of IVM is less than 1% of routine in vitro fertilization and embryo transfer techniques in many reproductive centers. In this review, we searched the MEDLINE database for all full texts and/or abstract articles published in English with content related to oocyte IVM mainly between 2000 and 2016. Many different aspects of the IVM method may influence oocyte potential,including priming, gonadotrophin, growth factors, and culture times. The culture conditions of IVM result in alterations in the oocyte or cumulus cell transcriptome that are not observed under in vivo culture conditions. Additionally, epigenetic modifications, such as DNA methylation or acetylation, are also different between in vitro and in vivo cultured oocytes. In sum,current IVM technique is still not popular and requires more systematic and intensive research to improve its effects and applications. This review will help point our problems, supply evidence or clues for future improving IVM technique, thus assist patients for fertility treatment or preservation as an additional option.
