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Activated proline‐rich tyrosine kinase 2 regulates meiotic spindle assembly in the mouse oocyte 下载免费PDF全文
Xiao‐Qian Meng Bing Cui Dong Cheng Hui Lyu Li‐Gang Jiang Ke‐Gang Zheng Shu‐Zhen Liu Jie Pan Cong Zhang Jing Bai Jun Zhou 《Journal of cellular biochemistry》2018,119(1):736-747
Proline‐rich tyrosine kinase 2 (PYK2), a member of the protein tyrosine kinase family, plays an important role in various cellular processes. PYK2 can be phosphorylated on tyrosine 402 by diverse stimuli at the cell surface, and recent studies have shown that this activated form of PYK2 is enriched in oocytes and required for fertilization. However, the subcellular localization and functions of activated PYK2 in oocytes remain elusive. In this study, we demonstrate that the localization of p‐PYK2 undergoes dynamic changes during in vitro maturation of mouse oocytes. The signal of p‐PYK2 is initially dispersed in the cytoplasm, but begins to decorate organized microtubules after the germinal vesicle breakdown and localizes to spindle poles at metaphase. Our data further show that p‐PYK2 colocalizes with γ‐tubulin from the germinal vesicle stage through the end of meiosis in mouse oocytes. Nocodazole treatment and washout experiments confirm that p‐PYK2 associates with the oocyte spindle and spindle poles. Moreover, pharmacological inhibition of PYK2 activity dramatically alters the morphology of the bipolar spindle and prevents oocyte maturation. Together, these data suggest that activated PYK2 may function as a component of the microtubule organizing center to regulate spindle assembly during the meiotic process of mouse oocytes. 相似文献
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Tanghao Liu Yuanyuan Zhou Zhen Li Lin Zhang Ming‐Gang Ju Deying Luo Ye Yang Mengjin Yang Dong Hoe Kim Wenqiang Yang Nitin P. Padture Matthew C. Beard Xiao Cheng Zeng Kai Zhu Qihuang Gong Rui Zhu 《Liver Transplantation》2018,8(22)
Formamidinium (FA)‐based lead iodide perovskites have emerged as the most promising light‐absorber materials in the prevailing perovskite solar cells (PSCs). However, they suffer from the phase‐instability issue in the ambient atmosphere, which is holding back the realization of the full potential of FA‐based PSCs in the context of high efficiency and stability. Herein, the tetraethylorthosilicate hydrolysis process is integrated with the solution crystallization of FA‐based perovskites, forming a new film structure with individual perovskite grains encapsulated by amorphous silica layers that are in situ formed at the nanoscale. The silica not only protects perovskite grains from the degradation but also enhances the charge‐carrier dynamics of perovskite films. The underlying mechanism is discussed using a joint experiment‐theory approach. Through this in situ grain encapsulation method, PSCs show an efficiency close to 20% with an impressive 97% retention after 1000‐h storage under ambient conditions. 相似文献
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Oxygen Evolution: FeN4 Sites Embedded into Carbon Nanofiber Integrated with Electrochemically Exfoliated Graphene for Oxygen Evolution in Acidic Medium (Adv. Energy Mater. 26/2018) 下载免费PDF全文
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Guangjun Nan Xu Zhang Mojtaba Abdi‐Jalebi Zahra Andaji‐Garmaroudi Samuel D. Stranks Gang Lu David Beljonne 《Liver Transplantation》2018,8(13)
Lead tri‐iodide methylammonium (MAPbI3) perovskite polycrystalline materials show complex optoelectronic behavior, largely because their 3D semiconducting inorganic framework is strongly perturbed by the organic cations and ubiquitous structural or chemical inhomogeneities. Here, a newly developed time‐dependent density functional theory‐based theoretical formalism is taken advantage of. It treats electron–hole and electron–nuclei interactions on the same footing to assess the many‐body excited states of MAPbI3 perovskites in their pristine state and in the presence of point chemical defects. It is shown that lead and iodine vacancies yield deep trap states that can be healed by dynamic effects, namely rotation of the methylammonium cations in response to point charges, or through slight changes in chemical composition, namely by introducing a tiny amount of chlorine dopants in the defective MAPbI3. The theoretical results are supported by photoluminescence experiments on MAPbI3?mClm and pave the way toward the design of defect‐free perovskite materials with optoelectronic performance approaching the theoretical limits. 相似文献
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Structural Engineering of Multishelled Hollow Carbon Nanostructures for High‐Performance Na‐Ion Battery Anode 下载免费PDF全文
De‐Shan Bin Yunming Li Yong‐Gang Sun Shu‐Yi Duan Yaxiang Lu Jianmin Ma An‐Min Cao Yong‐Sheng Hu Li‐Jun Wan 《Liver Transplantation》2018,8(26)
Hard carbon has long been considered the leading candidate for anode materials of Na‐ion batteries. Intensive research efforts have been carried out in the search of suitable carbon structure for an improved storage capability. Herein, an anode based on multishelled hollow carbon nanospheres, which are able to deliver an outstanding electrochemical performance with an extraordinary reversible capacity of 360 mAh g?1 at 30 mA g?1, is designed. An interesting dependence of the electrochemical properties on the multishelled structural features is identified: with an increase in the shell number of the model carbon materials, the sloping capacity in the charge/discharge curve remains almost unchanged while the plateau capacity continuously increases, suggesting an adsorption‐filling Na‐storage mechanism for the multishelled hollow hard carbon materials. The findings not only provide new perspective in the structural design of high‐performance anode materials, but also shed light on the complicated mechanism behind Na‐storage by hard carbon. 相似文献