肥大心肌细胞自体吞噬的细胞化学研究

肥大心肌细胞自体吞噬的细胞化学研究韩玉升，陈玉英，汤雪明（上海第二医科大学生物物理教研室，上海２０００２５）本实验研究大鼠腹主动脉结扎造成左心室壁心肌细胞肥大，并引起线粒体变化。用溶酶体标志酶胞嘧啶单核苷酸酶（ＣＭＰ酶）细胞化学方法观察肥大心肌细胞线...     

两种蛋白在大鼠睾丸间质细胞内吞途径的研究

两种蛋白在大鼠睾丸间质细胞内吞途径的研究陈晓群，张蕙心，汤雪明（上海第二医科大学，上海２０００２５）细胞内吞是细胞从外界摄取大分子的一种重要方式。对于不同的大分子，细胞采取不同的方式内吞，并通过不同的途径对它们进行处理。本研究通过观察人绒毛膜促性腺激...     

新生大鼠造釉细胞中NLy的电镜观察

造釉细胞是牙体发育过程中牙釉质的形成细胞 ,由造釉器的内釉上皮发育而来 ,与牙釉质的基质形成和钙化关系密切。溶酶体是细胞内的一种细胞器 ,线状溶酶体为溶酶体系统的独立组成部分。以往认识的溶酶体是细胞的消化器官 ,近年的研究显示 ,溶酶体 ,尤其是线状溶酶体( NLy) ,可能参与细胞内的物质转运功能。曾有研究者在成熟的大鼠造釉细胞中观察到一种被称为管状溶酶体的结构[1] ,但对发育期造釉细胞中线状溶酶体的研究报道目前尚未见到。本研究运用电镜酶细胞化学技术 ,观察新生大鼠的造釉细胞 ,以探讨其线状溶酶体的存在和作用。材料与方…     

赞育丹 对大鼠LRH模型睾丸和GTH细胞超微结构的影响

以大剂量LRH-A200μg/次,隔日皮下注射持续60天,造成雄性大鼠生殖功能障碍的动物模型。以“赞育丹”进行实验性治疗,以电镜技术为手段,对模型组、中药组和对照组动物的睾丸和垂体促性腺激素(GTH)细胞进行观察。结果表明,“赞育丹”对大剂量LRH类似物的抗精子发生效应有一定的拮抗作用;同时也表明,中医“肾主生殖”理论与下丘脑—垂体—性腺轴有关。     

The grid lens effect in convergent Pierce guns

In a conventional Pierce-type gun, the anode aperture causes a potential reduction in the cathode-anode region from the ideal Langmuir potential distribution. For low-voltage gating of the electron beam, a mesh grid of spherical shape (conforming to an equipotential surface) is used in front of the cathode. When this grid is operated at the Langmuir potential depicted by its relative position, there is a difference in the potential gradients on its two sides. This difference causes a lens action at each mesh element which results in a displacement of the actual electron trajectory from the ideal laminar trajectory in the region beyond the anode. A means for calculating these displacements as a function of distance along the axis is developed. As the grid lenses are divergent, the images of the mesh elements in any plane beyond the anode are larger than those for ideal laminar flow, resulting in a current density distribution which differs from that of the ideal beam. A means of calculating the current density profile by summing the effects of the grid lenses is devised, and the method is applied to a sample gun design to illustrate the effect on the current density distribution.     

人肝细胞自噬性凋亡的形态学观察

为了进一步完善形态学的分型标准以及研究调控自噬对细胞凋亡的影响 ,采用去血清诱导自噬和3ＭＡ抑制自噬 ,同时施与凋亡诱导剂 ,观察细胞超微结构的改变。正常人肝ＬＯ2细胞株去血清培养12ｈ诱导自噬之后 ,ｃｉｓｐｌａｔｉｎ(3μｌ ｍｌ)加入 16 40培养基诱导ＬＯ2细胞凋亡 16ｈ和 3-ＭＡ自噬抑制剂(6 0 0 μｇ ｍｌ) ,30ｍｉｎ后加入ｃｉｓｐｌａｔｉｎ(3μｌ ｍｌ)混合培养ＬＯ2细胞 16ｈ。ＪＥＭ 12 0 0ＥＸ透射电镜观察、摄片。正常ＬＯ2细胞胞质丰富 ,核仁明显 ,自噬现象少见。单施加凋亡诱导剂的细胞 ,可见凋亡细胞的形态多样 ,细胞…     

Calculation studies on point defects in perovskite solar cells

The close-to-optimal band gap, large absorption coefficient, low manufacturing cost and rapid increase in power conversion efficiency make the organic-inorganic hybrid halide (CH₃NH₃PbI₃) and related perovskite solar cells very promising for commercialization. The properties of point defects in the absorber layer semiconductors have important influence on the photovoltaic performance of solar cells, so the investigation on the defect properties in the perovskite semiconductors is necessary for the optimization of their photovoltaic performance. In this work, we give a brief review to the first-principles calculation studies on the defect properties in a series of perovskite semiconductors, including the organic-inorganic hybrid perovskites and inorganic halide perovskites. Experimental identification of these point defects and characterization of their properties are called for.     

睾丸间质细胞内体的细胞化学研究

电镜细胞化学实验结果表明，在睾丸产是质细胞中早期内体在形态上表现为一种形状不规则的低密度多泡体，其管状突起可能含有回收到细胞表面的受体。晚期内体在形态上表现为高密度多泡体，接受来自高尔基体的含有溶酶体听运输小泡，呈不同程度的ＣＭＰ酶阳性反应，最后成熟成为溶酶体。     

植物细胞胞吞途径及其研究方法

胞吞作用(Endocytosis)通过对质膜脂类、整合蛋白以及胞外物质的内化严格控制物质和信号的交流,是细胞与外界环境交流和细胞内稳态维持的重要方式之一。相较于动物和酵母细胞,植物细胞胞吞作用的研究相对滞后。随着拟南芥突变体库的建立以及药理学等方法的应用,人们对植物细胞膜泡运输的调节机制有了新的认识。本文阐述植物细胞中主要的胞吞途径,并着重总结植物细胞胞吞途径研究常用的成像技术和生物化学方法,为今后开展胞吞途径的系统研究提供技术和方法上的参考。     

The nature of point defects in CdTe

High temperature in-situ Hall effect measurements in CdTe single crystals grown by different techniques at 500–1,200 K under well-defined Cd and Te vapor pressure were made. It was established that native point defects (PD) Cd _i ²⁺ and V _Te ²⁺ are dominant at T>770 K in Cd-rich CdTe. Their formation enthalpies were determined (ΔH _VTe ²⁺ =1.3 eV; ΔH _Cdi ²⁺ =2.5 eV). It was shown that V _Te ²⁺ dominate at low temperatures and Cd _i ²⁺ begin to prevail at T>930 K. In Te-saturated CdTe at heating up to ～800 K, the hole density was Te vapor pressure independent. At higher temperatures (HT), the conductivity changed to intrinsic type, turning then into n-type. The results were explained in the framework of Kröger’s quasichemical formalism assuming the presence of an electrically active foreign point defect, the oxygen acceptor. The PD structure modeling demonstrated satisfactory agreement with experimental results both for temperature and component vapor pressure dependencies.     

Measurements and prediction of differential rain attenuation in convergent links

Measurements of differential rain attenuation in line-of-sight microwave and millimetre-wave convergent links were performed at two sites in Brazil. Cumulative distributions of differential rain attenuation for 36 pairs of links were obtained and an empirical prediction model has been derived.     

The detection and analysis of point processes in biological signals

A pragmatic approach to the detection and analysis of discrete events in biomedical signals is taken. Examples from both clinical and basic research are provided. Introductory sections discuss not only discreate events which are easily extracted from recordings by conventional threshold detectors but also events embedded in other information carrying signals. The primary considerations are factors governing event-time resolution and the effects limits to this resolution have on the subsequent analysis of the underlying process. The analysis portion describes tests for qualifying the records as stationary point processes and procedures for providing meaningful information about the biological signals under investigation. All of these procedures are desiged to be implemented on laboratory computers of modest computational capacity.     

关于有线电视用户编号的讨论

有线电视台在对有线电视网络用户进行信息化管理的时候 ,有些台对住户按地理方位进行了较详细的绘图 ,并且为每套房子编好了用户号 ,给已安装了有线电视的住户发了对应此号的用户卡 ,以标志其为网络中的合法用户 ,尚未安装的用户也给预留了编号 ,等待将来安装。这样的编号方式曾引起一些争论。作者持编号不能绝对固定的观点 ,写此文供同行参考。笔者认为 ,不能全部按图纸中为各房子预定好的号为住户编号 ,一套房子有些情况下只好给两个编号 ,原因是 :(1)若一套房子里住了两户人家 ,两家人都愿意安装自己的有线电视 ,分别来办理安装 ,安装处…