激光扫描共聚焦显微镜样品制备的改进方法用于8种纤毛虫表膜的观察

采用KMnO4作为固定剂,对传统的免疫荧光细胞化学技术进行改进,将制备好的样品用激光扫描共聚焦显微镜进行连续断层扫描和三维重建,清晰地呈现了8种纤毛虫的表膜以及纤毛模式,为原生动物纤毛虫表膜研究提供了一种可供借鉴的样品制备方法。     

纤毛虫扫描电镜样品制备中的一种新固定方法

本文利用KMnO_4和饱和HgCl溶液做为纤毛虫扫描电镜样品制备中的固定剂。利用这一方法在贻贝棘尾虫(Stylonychia mytilus),伍氏游仆虫(Euplotes woodruffi)、绿草履虫(Paramecium bursaria)、爽口虫(Climacostomum sp)等纤毛虫上得到令人满意的扫描电镜观察。其效果与国内外常用的戊二醛、OsO_4做为固定剂或Parameium氏液(OsO_4饱和HgCl溶液)相比看不出有什么不同。这样,利用KMnO_4替代OsO_4后,大大降低药品费用和对人体的损害。     

扫描电镜样品制备的改进方法用于纤毛虫特氏前口虫皮层的观察

人们观察纤毛虫或其他细胞表膜内表面结构的方法是利用透射电镜.但观察到的均为二维图像,展示其形态结构的三维图像尚未有过报道.本文介绍了本实验室在扫描电镜样品制备的破膜方法基础上,在特氏前口虫上的新改进.此改进的方法展示了应用于特氏前口虫后,所获得的表膜内表面皮层下三维立体结构观察的效果,从而为相关领域的研究者应用扫描电镜...     

琼脂铸模法制备透射电镜样品

本文介绍用琼脂铸模法制备透射电镜样品，如悬浮培养细胞、细菌、蓝藻、原生动物和花粉等细小分散的生物样品。该技术不但能将这类样品高度浓缩在一个微小的空间内，而且可简化样品制备步骤，减少样品损失，提高可观察样品的信息量。     

草履虫的扫描电镜观察

草履虫是原生动物门纤毛虫纲的代表动物。它对于细胞遗传和癌症的诊断有重要价值。用DMSO冷冻割断法和扫描电镜制样技术对草履虫进行处理和观察,能获得体表和体内微细结构的三维图象,提供一些新的信息。材料与方法:稻草浸液培养草履虫,2％lugol′s液缓慢地杀死,2.5％戊二醛和锇酸双固定,乙醇逐级脱水,乙酸异戊酯置换,CO_2临介点干燥,高真空浅射黄金,扫描电镜观察。断面样品用DMSO冷冻割断法。     

厚游仆虫（Euplotes crassus）大核核孔复合体研究

厚游仆虫（Ｅｕｐｌｏｔｅｓｃｒａｓｓｕｓ）大核核孔复合体研究李晖（厦门大学细胞生物学研究室，厦门３６１００５）细胞核核膜的核孔复合体的研究报道很多，但单细胞原生动物的核孔复合体研究甚少。腹毛类纤毛原生动物厚游仆虫有二个细胞核，即大核（营养核）、小核（...     

纤毛虫施氏腹柱虫细胞纤毛器微管的激光共聚焦显微观察

应用荧光紫杉醇荧光标记结合激光共聚焦显微术显示,土壤纤毛虫施氏腹柱虫(Gastrostyla steinii)细胞纤毛器微管胞器中,口围带和波动膜后端汇合处含口底托架及口后微管束;额腹横棘毛基部含前纵微管束、后纵微管束和横微管束;左、右缘棘毛基部含前纵微管束、后纵微管束、横微管束和基部微管芽。与目前了解的纤毛虫同类微管结构相比较,施氏腹柱虫显示出其适应于土壤环境而与水生纤毛虫有所区别的一些基本特征,其棘毛基部微管的组成及定位具有该种土壤纤毛虫细胞的特异性。形态发生中,老口围带全部保留,老的或先存的微管结构对新结构的发生和形成具有定位和物质贡献的作用,且老结构在新结构分化和成熟期间也经历着行使相应的生理功能及逐渐退化的过程。     

冠突伪尾柱虫腹皮层纤毛器的扫描电镜观察

应用扫描电镜观察显示了纤毛虫冠突伪尾柱虫(Pseudourostyla cristata)腹皮层纤毛器的形态和形态发生特征.其中每片口围带小膜包括4列副小膜,第1列仅包含3个基体,此列在翻领部与其余3列紧密排列,在领部则位于分隔两列相邻小膜之间的嵴上.口围带在翻领部具有长度不等的侧向纤毛.形态发生中,前仔虫口围带的翻领部和领部两端是完全更新形成的,领部其余部分则保留下来.后仔虫的口围带原基最初于左列中腹棘毛左侧形成.此外,形态发生期间老的口围带小膜后端一部分小膜保留,其随着逐步向后迁移,最后出现在后仔虫口围带的最前端,这部分老的口围带小膜可能对后仔虫口围带的形成有一定的物质贡献作用,或与中腹棘毛共同参与了后仔虫口围带的形成,这可能代表了腹毛类纤毛虫的一种新的口器形成模式.     

四膜虫S_1株rDNA的明场与暗场电镜观察

四膜虫(Tetrahymena)是一种单细胞的原生动物。近十几年来,在分子生物学特别是在真核细胞基因的结构与功能的研究中,越来越成为一个重要的实验动物。在四膜虫的大核中,其编码rRNA的基因扩增成上万个游离于染色体的独立的rDNA分子。为此,在对我国自己分离出来的一株四膜虫S_1株rDNA酶切图谱研究的同时,我们用明场和暗场电镜技术观察了它的rDNA的形态与大小,并与国外常用的一种四膜虫T.thermophila做了比较。用热酚法提取四膜虫DNA,经琼脂糖凝胶电泳纯化后的rDNA,按Kleinsehmidt法制备明场电镜样品,其中加质粒PBR322做为标样。暗场样品制备中,用间接真空蒸发法获得的厚约25A的碳膜蘸取样品,染色后,即可在电镜(JEM—200cx)下观察。     

"楔形"TEM样品的机械研磨制备技术

介绍了一种用机械研磨法制备集成电路TEM楔形样品的技术,讨论了该制样技术所需注意的关键点,并给出了判断样品薄区是否满足TEM分析要求的两种方法。楔形样品减薄技术兼具制样速度快和样品质量好的优点。该技术既可用于制备非定点TEM样品,也可用于制备定点的TEM样品。给出了用该技术制备的定点失效的MOS器件TEM照片。熟练的技术人员可以用此方法在半小时内完成一个样品的制备。     

Motion control of protozoa for bio-MEMS

This paper investigates the possibility as to whether protozoa can be treated as a living micro manipulator/actuator. Motion control of protozoa is made by using the negative galvanotaxis. First, a basic property test with a DC electric field showed that the Paramecium could be controlled by the electrical potential gradient. By using the eight-direction carbon electrode pool (4 mm electrode distance and 0.2 mm thickness), the operator can control the Paramecium in the aiming direction. Automatic motion control of protozoa is also achieved by using the image processing technology and fuzzy control method. The control method for rapid turning is also developed. To adopt this method to the automatic motion control program, Paramecium can be controlled along any shaped guide route. The actuation to rotate the micro-impeller (0.5 mm diameter) is achieved by Paramecium. These facts show that protozoa are able to be used as a micro manipulator/actuator     

锗掺杂磁控直拉单晶硅太阳电池

介绍了锗掺杂浓度为（1～1.5) E19cm-3的10Ω·cm磁控直拉单晶硅衬底上BSFR (back surface field and reflection）和BSR(back surface reflection)太阳电池的制备和电性能. BSR锗掺杂单晶硅太阳电池的AM0效率最高为12.3%. BSFR锗掺杂单晶硅太阳电池的AM0效率达到15%. 利用1MeV的高能电子对制备的锗掺杂单晶硅太阳电池进行了辐照实验. 作为对比，对全部常规10Ω·cm的CZ单晶硅太阳电池也进行了实验. 结果表明，锗掺杂浓度为（1～1.5)E19cm-3的磁控直拉单晶硅太阳电池的电性能和抗辐照性能与常规直拉硅太阳电池基本相同. 利用锗掺杂磁控直拉单晶硅片机械强度较高的优点，可以降低太阳电池生产过程破损率.     

Heterostructure solar cells

Heterostructure solar cells based on III–V compounds are studied. Record-high efficiencies are obtained for solar cells based on AlGaAs/GaAs heterostructures: 24.6% for 100-fold concentration of sunlight in outer space (AM0) and 27.5% for 100-fold concentration of the light on the ground (AM1.5). A substantial increase in radiation resistance is obtained for solar cells with a built-in Bragg mirror. Cascaded solar cells with efficiencies of up to 32% for 100 suns (AM1.5) are created and studied; in these cells the upper wide-gap materials are infrared transparent elements based on GaAs, while the lower narrow-band elements are made of GaSb or an InGaAs solid solution. Fiz. Tekh. Poluprovodn. 33, 1035–1038 (September 1999)     

Accurate Measurement and Characterization of Organic Solar Cells

Methods to accurately measure the current–voltage characteristics of organic solar cells under standard reporting conditions are presented. Four types of organic test cells and two types of silicon reference cells (unfiltered and with a KG5 color filter) are selected to calculate spectral‐mismatch factors for different test‐cell/reference‐cell combinations. The test devices include both polymer/fullerene‐based bulk‐heterojunction solar cells and small‐molecule‐based heterojunction solar cells. The spectral responsivities of test cells are measured as per American Society for Testing and Materials Standard E1021, and their dependence on light‐bias intensity is reported. The current–voltage curves are measured under 100 mW cm^–2 standard AM 1.5 G (AM: air mass) spectrum (International Electrotechnical Commission 69094‐1) generated from a source set with a reference cell and corrected for spectral error.     

Can the Shape of Nanoparticles Enable the Targeting to Cancer Cells over Healthy Cells?

Macropinocytosis is a consequence of oncogenic alterations of cancer cells while most healthy cells are non-macropinocytic. It is currently unclear whether macropinocytic cancer cells can be targeted rather than healthy cells, by adjusting the shape and size of nanoparticles. Herein, the endocytosis of two differently shaped nanoparticles; nanorods and nanospheres are compared in cancer and healthy cells. The cells are breast epithelial cancer cells (MCF7) and breast epithelial healthy cells (MCF10A) and pancreas cancer cells (PANC-1 cells) and non-tumourogenic patient-derived cancer-associated fibroblasts (CAFs). The endocytosis pathway is quantified by a combination of pair correlation microscopy and endocytosis inhibitors. MCF7 cells use clathrin-mediated endocytosis and macropinocytosis to take up the nanorods while MCF10A cells use predominantly clathrin-mediated endocytosis. Based on the comparison of endocytic behavior of cancer and healthy cells, MCF7 cells can be induced to take up more nanorods and suppress the metabolism and endocytosis of nanorods in MCF10A cells. The nanorods allow targeting to breast cancer MCF7 cells and pancreas cancer cells over the healthy cells. This study opens exciting possibilities for shape to target the cancer cells over healthy cells, by adjusting nanoparticle shape.     

High-efficiency GaAs solar cells

An updated review of the state of the art in the development of GaAs solar cells is provided, with emphasis on AlGaAs-GaAs cells suitable for space applications. A set of theoretically derived characteristics is given for this type of solar cell. Comparison of measured performance with theory shows excellent agreement. Data on the effects of radiation damage (high-energy electrons, protons, and neutrons) is also integrated into a form useful for evaluation purposes. Techniques for fabricating (AlGa)As-GaAs solar cells in quantities large enough for practical applications are discussed and are shown to have been demonstrated. The possibility of extending these techniques to the fabrication of very thin low-weight cells for space applications is also considered. Finally, the results obtained to date in the development of GaAs solar cells for applications requiring concentrated sunlight are reviewed, for terrestrial as well as for space applications. As a milestone toward the practical application of AlGaAs-GaAs solar cells in space systems, a brief account is provided on the development status of small experimental AlGaAs-GaAs solar-cell panels for specific space flights.     

The investigation of the radiation behavior of cells of energy-independent electrically reprogrammable memory based on self-formed conducting nanostructures. I. Mode of information storage

The results of the experimental investigation of the radiation behavior of cells with the use of the electroformed open Si-SiO₂-W sandwich structures as memory cells are presented. Information in these structures is coded by the width of a nanometer insulating gap in the conducting medium appearing on the free end of the silicon dioxide film during electroforming. The current-voltage characteristics determining their state (highly conducting or weakly conducting) before and after the effect of the X-ray radiation with different irradiation doses were monitored for the cells. It is shown that the state of the memory cells determined by the current at a voltage from 1 to 1.5 V does not vary in the mode of information storage (at zero voltages on conducting buses) even at the highest doses of the influence of the ionizing radiation (up to 6 million units). Considerable variations in the currents for voltages lower than 0.5 V are associated with the influence of the radiation on the semiconductor structures of the cells. The mechanisms of conductivity of the memory cells at low (up to 1.5 V) voltages and the mechanisms of their radiation degradation, mainly consisting of charge accumulation in the silicon dioxide layers, are discussed.     

Static-noise margin analysis of MOS SRAM cells

The stability of both resistor-load (R-load) and full-CMOS SRAM cells is investigated analytically as well as by simulation. Explicit analytic expressions for the static-noise margin (SNM) as a function of device parameters and supply voltage are derived. The expressions are useful in predicting the effect of parameter changes on the stability as well as in optimizing the design of SRAM cells. An easy-to-use SNM simulation method is presented, the results of which are in good agreement with the results predicted by the analytic SNM expressions. It is further concluded that full-CMOS cells are much more stable than R-local cells at a low supply voltage.     

a-Si太阳电池中非线性串联电阻效应(英文)

A non-linear resistance effect has been found in a-Si PIN solar cells. The dark I-V characteristics of the cells are described.Though the dependence of ln(Isc) on Voc under different light intensity for all the cells can be written Voc = nLKTln(Isc/Io') the differences between the dark and illuminated diode parameters(nd and nL, Io and Io') are varied for the cells with different performances. If the nd of the cell is about 2 then nL相似文献   

基于高效太阳电池的光诱导镀技术

介绍了光诱导镀(light-induced plating,LIP)应用于太阳电池的背景、发展历史及其工作原理。论述了光诱导镀技术对太阳电池性能的影响,并重点探讨了光诱导镀技术对太阳电池前表面电极接触性能的改善效果。同时,还讨论了光诱导镀技术应用于铝背表面场(Al-BSF)和激光烧制接触(laser fired contact,LFC)两种高效太阳电池上所取得的成果。当接触电阻成为串联电阻中的主要成分时,光诱导镀能够降低接触电阻、提高填充因子,从而提高电池的效率。光诱导镀特别适合于改善串联电阻较大的电池,利用光诱导镀也可以重新优化电池的烧结条件,得到更高的电池效率。