牛乳腺上皮细胞体外培养体系研究进展

通过有效的培养方法,可实现牛乳腺上皮细胞的体外培养,并且所获细胞具有正常的生理特性及功能,从而建立牛乳腺上皮细胞的体外培养体系。本文论述了国内外近年来此领域的研究进展,综合比较了各种培养体系的建立方法,并对在培养体系建立的基础上进行的相关应用研究进行了总结。     

拟南芥悬浮细胞中ERG437蛋白的细胞定位的初步观察

近来在大肠杆菌中新发现的Era蛋白（E.coli ras-like protein）是一类新的GTP结合蛋白,研究表明Era蛋白参与调节细胞分裂、细胞周期以及部分细胞代谢过程。植物中相关研究报道尚少,推测ERG蛋白可能定位在线粒体,并且与种子的正常发育相关。本实验通过构建植物表达载体初步观察了ERG437蛋白在拟南芥悬浮细胞中的定位情况,同时利用CoxⅣ蛋白初步观察到绝大部分ERG437蛋白定位于线粒体。     

流式细胞仪的新发展及其在生物医学研究中的应用

流式细胞仪是一种对细胞进行定量分析与分选的精密仪器，它分析速度快，特异性好和灵敏度高，是生物医学研究的强有力工具。本文在自己研制的流式细胞仪的基础上，结合国内外的最新动态，概述了该领域在仪器和技术方面的最新发展及其在生物医学研究中的应用。     

Era蛋白（E.coli ras-like protein）-一个可能参与真、原细胞信号调控的新分子开关

充足的证据表明G蛋白作为真核细胞的重要分子开关参与细胞的增殖调控以及部分代谢调控过程。而近来在大肠杆菌中新发现的Era蛋白（E.coli ras-like protein）则是与已知的三聚体G蛋白和小分子G蛋白不同的一种新的GTP结合蛋白。进一步的研究发现该类GTP结合蛋白不仅存在于原核的大肠杆菌中,而且在高等植物、人类细胞中均含有该蛋白的同源蛋白。大肠杆菌的Era蛋白主要位于细胞膜的内侧,细胞质中也有一定的分布;一些证据表明,真核细胞ERA（ERG）蛋白来源于原核细胞,定位于线粒体或者叶绿体。近来的研究证据表明ERA或者ERG蛋白有可能担负着与其它两类G蛋白同样重要的分子开关功能。已有的研究表明Era蛋白参与调节原核生物的细胞分裂、细胞周期以及部分细胞代谢过程;在哺乳动物细胞中,同源蛋白ERA可能与细胞周期的G1期调控以及细胞凋亡有关;真核植物中相关研究报道尚少,推测该蛋白可能与种子的正常发育有关。本文主要介绍原核Era蛋白和真核ERA蛋白的结构特点以及功能研究进展。     

雌二醇诱导人正常肝细胞的凋亡以及对细胞周期的影响

目的：观察雌二醇对诱导人正常肝细胞的的凋亡,并且研究其对细胞周期的影响。方法：采用人肝细胞为实验对象,用he染色观察细胞形态学变化;流式细胞记数仪检测细胞周期,AnnexinⅤ/PI双重染色定量检测早期细胞凋亡及Bcl-2/Bax的表达改变。结果：雌二醇48h可以明显抑制正常肝细胞株的增生与活力,诱导细胞的凋亡,且对细胞周期的影响非常显著。结论：其机制可能与Bcl-2/Bax表达的下调有关。     

Four-color staining combining fluorescence and brightfield microscopy for simultaneous immune cell phenotyping and localization in tumor tissue sections

Immune-cell infiltration is frequently seen within human solid tumors. A detailed phenotypic analysis of these cells may aid in the understanding of an antitumor immune response. Standard hematoxylin/eosin and conventional immunohistochemical stainings are helpful, but have major limitations in the number of markers that can be identified and localized per tissue section. Therefore, we developed a combined fluorescence and brightfield microscopic technique by using both immunofluorescence and immunogold-silver methods, thereby discriminating three different leukocyte markers plus one tumor marker simultaneously in a single section. This enabled us to study both phenotype and location of infiltrating immune cells in colorectal tumors. We used a two-step staining in which primary and secondary antibodies were selected for minimal cross-reactivity. Furthermore, the secondary fluorescent antibody conjugates were selected for minimal spectral overlap. For computer-assisted analysis the brightfield microscopy image was combined with the fluorescence microscopy images. This combination of techniques provides a powerful tool for detailed multiparameter microscopic analysis of formalin-fixed, paraffin-embedded tissue sections in general and for tumor-immune cell infiltration in particular.     

Simultaneously identifying S-phase labelled cells and immunogold-labelling of vinculin in focal adhesions

A new combination of autoradiography and immunolabelling techniques is presented that allows the simultaneous identification of both S‐phase cells and their focal adhesions using scanning electron microscopy. The technique allows both labels to be discerned visually by their unique shapes and location within and on the cell. S‐phase cells were radio‐labelled with a pulse of tritiated thymidine, selectively incorporated into synthesizing DNA. The cells were then immunogold‐labelled for the focal adhesion protein, vinculin, prepared for autoradiography, and embedded in resin. The resin was then polymerized before removing the substrate, to expose the embedded cell undersurface. Electron‐energy ‘sectioning’ of the sample by varying the accelerating voltage of the electron beam allowed separate S‐phase cell identification in one electron‐energy ‘section’ and visualization of immunogold label in another ‘section’, within the same cell. As a result of applying this technique it was possible to positively identify S‐phase cells and immunogold‐labelled focal adhesions on the same cell simultaneously, which could be used to quantify focal adhesion sites on different substrates.     

SIEMENS 840D数控系统钻孔循环的研究

针对UG、MASTERCAM、CAxA等诸多CAM软件的后处理无法生成SIEMENS 840D可执行的钻孔循环,通过对SIEMENS 840D标准循环的研究,找到了一种方法,并成功地解决了SIEMENS840D钻孔循环参数设定的方法与意义.文章详细的讲述了SIEMENS 840D数控系统中,钻孔循环cycle81、cycle82以及cycle83中各个参数设定的意义和应用方法.     

电加热炉控制的免疫PID应用研究

温控系统在工业现场是一个大滞后、强耦合、非线性的系统,常规PID控制器很难取得优良的控制效果。文章依据免疫系统的自适应反馈调节作用,提出了免疫PID控制器的实现方法,并将其应用到常规温度控制系统中。仿真结果表明,免疫PID控制器具有良好的控制品质,当系统发生扰动时具有较强的鲁棒性和自适应能力。     

Sex differences in songbirds 25 years later: What have we learned and where do we go?

About 25 years ago, Nottebohm and Arnold reported that there are profound male-biased sex differences in volume in selected nuclei in telencephalic portions of the song control system. This review focuses on issues related to the cellular bases of these sex differences in volume and comparative studies that might elucidate the function of this variation between the sexes. Studies utilizing a variety of neurohistological methods in several different species to define the boundaries of two key telencephalic song nuclei HVc and the robust nucleus of the archistriatum (RA) all tend to find a sex difference in volume in agreement with Nissl-defined boundaries. Sex differences in volume in nuclei such as HVc and RA are associated with differences in cell size and cell number. Other attributes of the phenotype of cells in these nuclei are also different in males and females such as the number of cells expressing androgen receptors. Comparative studies have been employed to understand the function of these sex differences in the brain. In some songbird species, females sing rarely or not at all, and the brain nuclei that control song are many times larger volume in males than females. In other species, males and females sing approximately equally, and the brain nuclei that control song are approximately equal between the sexes. Recently, statistical methods have been employed to control for phylogenetic effects while comparing the co-evolution of traits. This analysis indicates that the evolution of sex differences in song has co-evolved with the evolution of sex differences in singing behavior in songbird species. Future studies should focus on the function of the smaller song control nuclei of females and investigate the role these nuclei might play in perception as well as in production. Microsc. Res. Tech. 54:327–334, 2001. © 2001 Wiley-Liss, Inc.     

基于单胞模型镍基单晶高温合金低周疲劳寿命的预测

基于镍基单晶高温合金的微观尺度结构特征,建立了γ/γ′双相单胞有限元模型,并基于能量耗散理论,引入统一表征非对称载荷循环特性和拉/扭多轴效应的k参量,以循环塑性应变能作为损伤参量,建立了镍基单晶高温合金低周疲劳寿命预测模型;分别利用宏观有限元模型和γ/γ′双相单胞微观有限元模型对[001]取向的DD3、PWA1480和CMSX-2镍基单晶高温合金的单轴、多轴低周疲劳试验过程进行数值模拟。结果表明:微观单胞有限元模型反映了试验合金的微观结构特性,其预测精度明显优于宏观有限元模型的;上述3种合金几乎所有的试验数据分别落在1.3,2.0和2.0倍偏差分布带内。     

免疫PID在温控系统中的应用研究

借鉴生物免疫系统的反馈调节作用,提出了免疫PID控制策略,并将其应用到工业水箱的温度控制系统中.经仿真研究表明,免疫PID控制器比传统的PID控制器拥有更快的响应速度及更优秀的控制品质,同时当系统发生扰动时也具有较强的鲁棒性和自适应能力.