肝脏干细胞研究进展

肝干细胞是一类具有自我更新能力和多项分化潜能的细胞 .在一定病理条件下可向肝细胞和胆管上皮细胞、胰腺外分泌上皮等有限的几种组织分化 ,具有多项分化增殖潜力 ,本文将就肝干细胞分类、表面标志、来源及人类肝干细胞的研究做一综述 .     

Wnt signaling: multiple functions in neural development

Wnt signaling has proven to be essential for neural development at various stages and across species. Wnts are involved in morphogenesis and patterning, and their proliferation-promoting role is a key function in stem cell maintenance and the expansion of progenitor pools. Moreover, Wnt signaling is involved in differentiation processes and lineage decision events during both central and peripheral nervous system development. Additionally, several reports point to a role of Wnt signaling in axon guidance and neurite outgrowth. This article reviews and consolidates the existing evidence for the functions of Wnt signaling in neural development.Received 10 December 2004; received after revision 19 January 2005; accepted 21 January 2005     

CMJ-17A液压钻车岩石作业线在西山矿区官地矿的应用

结合西山矿区目前岩巷掘进工艺，对引进的CMJ-17A型液压钻车系列装备的掘进速度、经济效益进行了分析，说明引进液压钻车岩石作业线是推进开拓巷道工艺改革、实现集约化生产的理想选择。     

A microenvironment,rather than chemical,initiates the cardiomyogenic differentiation of marrow stromal cells

To investigate the potential of cardiomyogenic differentiation of rat hone marrow stromal cells (MSCs), they were exposed to 5-azacytidine treatments (single/repeat) at varying concentrations (3, 5, 10μmol/L) and the fates of the cells were analyzed by immunocytochemistry, Western blot and the reporter gene of enhanced cyan fluorescent protein (ECFP) under the control of ventricular myosin light chain 2 (MLC2v) promoter. MSCs were also cocultured with cardiomyocytes for periods up to 16 days, and the expression of cardiac myosin heavy chain(MHC) and troponin Ⅰ (Tn I) proteins was analyzed. After the induction with 5-azacytidine, neither spontaneously beating ceils nor myotubes were found; MHC and Tn I proteins were also undetectable and no ECFP-positive MSCs were detected. But when cocultured with cardiomyocytes, spontaneously contracting MSCs were observed and cardiac specific proteins could be detected. The results proved that the novel effects of 5-azacytldine on the cardiomyogenic differentiation of MSCs should be questioned and a direct intercellular communication with cardiomyocytes is necessary for MSCs to differentiate into cardiomyocytes.     

深孔加工的负压外排屑探讨

分析小深孔钻削的加工方法．利用负压抽吸原理，改善外排屑状况，提高小深孔排屑的效率及降低表面粗糙度     

液压凿岩机的计算机辅助设计

本文运用计算机模拟方法,得出了园柱阀液压凿岩机的优化工况。为设计新产品提供了选择参数的依据;同时把活塞及阀的运动过程直观地表现在屏幕上,收到了较好的动画效果。     

BrdU标记骨髓间充质干细胞的研究

目的:探讨5-溴脱氧尿嘧啶核苷(5-Bromo-21-deoxyuridine,BrdU)标记骨髓间充质干细胞(Mesenchymal stem cells.MSCs)的可行性.方法:分离培养骨髓MSCs,经BrdU标记不同时间,免疫细胞化学鉴定.结果:MSCs的CD44、CD54免疫细胞化学染色阳性率达90%以上.BrdU标记的阳性细胞率随标记时间延长而逐渐增高,标记72h阳性率达85%以上.结论:以10μmol/L的BrdU标记骨髓MSCs的最佳时间是72h.     

干细胞研究进展

由于干细胞具有自我更新和多向分化潜能的功能,使得人们用干细胞治疗多种疾病成为可能.就干细胞的研究概况、研究技术、干细胞技术的市场前景以及干细胞研究面临的问题等作一概述.     

磷酸钙与胶原双相多级仿生骨组织工程支架研究

磷酸钙与胶原是天然骨组织的重要组成成分,介绍了一种仿生设计磷酸钙与胶原双相复合的多级仿生骨组织支架.采用双氧水发泡技术精确定制磷酸钙支架孔结构,结合真空灌注胶原以及仿生矿化技术,构建磷酸钙,胶原双相多级仿生骨组织支架,材料的孔结构及化学组分可实现定制设计.通过对支架材料测试表征,结果显示,这种无机/有机/无机多级仿生支架材有良好的力学性能.材料的体外细胞实验结果证实,这种多级仿生支架材料具有良好的生物相容性.