Human embryonic stem cells-derived endothelial cell therapy facilitates kidney regeneration by stimulating renal resident stem cell proliferation in acute kidney injury

Endothelial cell therapy has been implicated to enhance tissue regeneration and vascularization in ischemic kidney. However, no published study has yet examined direct effects of endothelial cell treatment in kidney recovery. This study investigated the therapeutic efficacy of endothelial cells in a mouse model with acute kidney injury (AKI). Thus, human embryonic stem cells-derived endothelial cells (hESC-ECs) labeled with a reporter system encoding a double fusion reporter gene for firefly luciferase (Fluc) and green fluorescent protein (GFP) were characterized by Fluc imaging and immunofluoresence staining. Cultured hESC-ECs (1×106) were injected into ischemic kidney shortly after AKI. Survival of the transplanted hESC-ECs was monitored in vivo from day 1 to 14 after endothelial cell transplantation and potential impact of hESC-EC treatment on renal regeneration was assessed by histological analyses. We report that a substantial level of bioluminescence activity was detected 24 h after hESC-EC injection followed by a gradual decline from 1 to 14 d. Human ESC-ECs markedly accelerated kidney cell proliferation in response to ischaemia-induced damage, indicated by an elevated number of BrdU+ cells. Co-expression of Sca-1, a kidney stem cell proliferation marker, and BrdU further suggested that the observed stimulation in renal cell regeneration was, at least in part, due to increased proliferation of renal resident stem cells especially within the medullary cords and arteriole. Differentiation of hESC-ECs to smooth muscle cells was also observed at an early stage of kidney recovery. In summary, our results suggest that endothelial cell therapy facilitates kidney recovery by promoting vascularization, trans-differentiation and endogenous renal stem cell proliferation in AKI.     

Recent progress in immobilization of late-transition-metal complexes with diimine ligands for olefin polymerization

Late-transition-metal(LTM) catalysts are a family of very flexible ethylene polymerization catalysts because their catalytic performance can be easily adjusted by modifying the ligand structure.Their less oxyphilicity character,which may promote the production of copolymers from ethylene and polar comonomers,is another aspect that attracts much attention in both academic and industrial fields.The immobilization of LTM catalysts on spherical supports is a crucial step prior to their use in the industrial processes of gas-phase or slurry polymerizations.This paper reviews recent developments in supported LTM catalysts for olefin polymerization,and summarizes loading methods and mechanisms of the immobilization of LTM catalysts on inorganic,organic,and inorganic-organic materials,and the effects of immobilization on catalytic activity,polymerization mechanism,and polymer morphology.     

基于知识流优化的业务流程重组

基于业务流程和其内部知识特征,提出一种从知识流优化角度进行流程重组的方法.通过识别业务流程及流程知识,构造基于业务流程的知识地图及流程角色关系网,挖掘业务流程和组织结构的知识流潜在联系,并提出不同的知识流优化原则,对业务流程和组织结构进行优化,实现业务流程重组.通过实例说明利用知识流的业务流程重组方法能改善业务性能,促使组织结构更加合理化及组织知识水平提高.     

基于PROCAST软件的铸锭形状仿真分析

目前对于硅锰合金的主流生产方式为坑池铸造,但该方法易产生严重粉尘污染并造成资源浪费.为了解决该问题,当前硅锰合金行业设计并制造了一种连铸粒化设备,利用锭模铸造方法加工硅锰合金,能够有效减少污染、节约材料并提高生产效率.为了对锭模铸造方法进行更全面的认识,利用PROCAST仿真软件,对半球体和半球圆柱体铸锭的铸造进行仿真...     

低阻硅TSV与铜填充TSV热力学特性对比分析

对低阻硅TSV以及铜填充TSV的热力学性能通过有限元仿真的方法进行对比分析.低阻硅TSV在绝缘层上方以及低阻硅柱上方的铝层区域中凸起最为显著,且高度分别为82 nm和76 nm;铜填充TSV的凸起位置主要集中在通孔中心铜柱的上方,最大值为150 nm.应力方面,低阻硅TSV在绝缘层两侧的应力最大,且最大值为1 005 MPa;铜填充TSV在中心铜柱外侧应力最大,且最大值为1 227 MPa.另外,两种结构TSV的界面应力都在靠近TSV两端时最大.低阻硅TSV界面应力没有超过400 MPa,而铜填充TSV在靠近其两端时界面应力已经超过800 MPa.综上所述,相比于铜填充TSV,低阻硅TSV具有更高的热力学可靠性.      

一株新型溶藻弧菌噬菌体φV039C的生物学特性和全基因组分析

对一株溶藻弧菌噬菌体φV039C进行了生物学特性和全基因组序列的研究。经透射电镜观察可见,噬菌体φV039C头部为正廿面体结构,直径58.9 nm,具长105.2 nm的尾部;采用双层平板法检测,其最佳感染复数为0.1;通过一步生长曲线计算可得,噬菌体φV039C的潜伏期为20 min,爆发期为10 min,裂解量为163 pfu/cell;利用第三代单分子测序平台进行全基因组测序分析,其基因组全长43 405 bp,G+C含量为42.95%,74个开放阅读框（ORF）主要为噬菌体的结构、DNA复制和裂解有关的基因;在NCBI数据库中进行基因组比对,发现与其最接近的长尾噬菌体科的溶藻弧菌噬菌体NF和副溶血弧菌噬菌体Seahorse的覆盖率仅为11%（覆盖区域的相似度分别为92.2%和93.3%）,此外,基于裂解酶构建的系统进化树也表明,φV039C与二者处于距离最近的分支。由此得出,溶藻弧菌噬菌体φV039C是一株新型的噬菌体,分类上应归属有尾噬菌体目长尾噬菌体科。     

Refinement of primary Si grains in Al–20%Si alloy slurry through serpentine channel pouring process

In this study, a serpentine channel pouring process was used to prepare the semi-solid Al–20%Si alloy slurry and refine primary Si grains in the alloy. The effects of the pouring temperature, number of curves in the serpentine channel, and material of the serpentine channel on the size of primary Si grains in the semi-solid Al–20%Si alloy slurry were investigated. The results showed that the pouring temperature, number of the curves, and material of the channel strongly affected the size and distribution of the primary Si grains. The pouring temperature exerted the strongest effect, followed by the number of the curves and then the material of the channel. Under experimental conditions of a four-curve copper channel and a pouring temperature of 701℃, primary Si grains in the semi-solid Al–20%Si alloy slurry were refined to the greatest extent, and the lath-like grains were changed into granular grains. Moreover, the equivalent grain diameter and the average shape coefficient of primary Si grains in the satisfactory semi-solid Al–20%Si alloy slurry were 24.4 μm and 0.89, respectively. Finally, the refinement mechanism and distribution rule of primary Si grains in the slurry prepared through the serpentine channel pouring process were analyzed and discussed.     

Investigation of rheo-diecasting mold filling of semi-solid A380 aluminum alloy slurry

The rheo-diecasting mold filling capacity and the microstructure of the semi-solid A380 aluminum alloy slurry were investigated. The results show that the mold filling capacity was strengthened with increasing pouring temperature or increasing injection pressure. Under certain process parameters, the mold cavity was fully filled. However, the mold filling capacity decreased with increasing holding time. The mold filling capacity was improved with increasing shape factor of primary α(Al) grains; however, the solid fraction and the grain size significantly increased at the same time. In addition, the microstructures along the route of the spiral samples obviously differed. The grain size decreased gradually from the near-end to the far-end, whereas the shape factor increased gradually.     

双基地雷达的侦察识别

本文主要探讨双基地雷达的侦察识别方法。在分析双基地雷达特征的基础上，提出了两种双基地雷达的识别方法，简单识别法只能识别双基地雷达发射站并确定其参数；相关识别法能同时对双基地雷达发射站和接收站实现侦察识别和定位。计算机模拟证实了这两种识别方法的可行性和有效性。     

基于Matlab的多速度模式电梯群控系统模型仿真

多速度模式运行是现代中高速电梯的重要特征，而运行仿真是电梯群控仿真研究的基本环节。应用面向对象技术和基于事件扫描的数字仿真技术，在通用的Matlab开发环境中实现了电梯的多速度模式仿真，为电梯群控策略的研究与开发提供了优良的基础平台。仿真实验引进了一种简单而新型的群控策略，仿真结果表明该仿真平台的实用性，具有一定的应用价值。