Detection of glycoconjugates by lectin gold labelling, silver enhancement, and scanning electron microscopy

A method for detecting glycoconjugates on cell surfaces in scanning electron microscopy is described. Terminal saccharides were specifically recognized by a lectin conjugated to biotin, and, after incubation with an anti-biotin antibody conjugated to colloidal gold, silver enhancement was used to produce deposits large enough to be detected in standard scanning electron microscopes. Secondary electron images revealed the ultrastructure of the tissue investigated, while backscattered electron images showed the distribution of lectin binding sites. Using digital recording and processing, the two channels were combined in colour-encoded images. The new method brings together lectin histochemistry and scanning electron microscopy and thus allows the three-dimensional distribution of glycoconjugates to be analysed at an ultrastructural level.     

表面铺展技术在联会复合体电镜研究中的应用

本文较详细地介绍了本室改进的表面铺层－硝酸银染色制备联会复合体（SC）电镜样品技术。取小鼠睾丸组织制成细胞悬液，取少量悬液滴在0．4％KCl液珠表面上以通过表面张力使SC铺展开，用涂有Formvar膜的载玻片蘸取细胞，干燥后用多聚甲醛固定，硝酸银染色，光镜下找到要观察的细胞，然后转移到50目铜网上，电镜下既可看到整个SC核,,地可观察同源染色体的联会过程，SC的超微结构及各种类型的SC畸变，该技术可广泛应用于细胞遗传学，遗传毒理学，生殖生物学等诸多学科。     

光诱导镀改善太阳电池填充因子的研究

本文采用常规的太阳电池工艺制备了一批单晶硅电池片,退火后得到了填充因子迥异的结果。比较了光诱导镀前后电池参数尤其是串联电阻,并分析了光诱导镀提升填充因子的机理。利用扫描电镜（SEM）观察了去除体银后的微观结构,证明了差填充因子太阳电池在光诱导镀后填充因子的提高得益于烧结中形成的银晶粒的充分利用。文中还提出了将光诱导镀应用于接触电阻较大的电池,如纳米柱电池和径向结电池的可能性。     

实验性慢性缺氧与肺血管结构的重建

目的：主要研究慢性缺氧与肺血管结构重建的关系,利用常压缺氧舱建立大鼠缺氧性肺动脉高压模型。实验动物分为3组：缺氧3天组、7天组、14天组。通过免疫组化的方法检测一氧化氮合成酶(NOS)的表达和含量,部分标本通过电镜观察。结果：在缺氧过程中,肺血管的胶原纤维明显增生,超微结构观察显示血管在早期可见内皮细胞损伤并伴有血小板性血栓形成;到后期出现肌纤维母细胞和胶原纤维增生。实验显示随缺氧时间的延长内皮细胞NOS的含量逐渐升高,而肺血管内源性的舒张反应反而降低,管腔狭窄,血流阻力加大。文中讨论了慢性缺氧与肺血管结构重建的关系,肺缺氧性肺动脉高压的机理,内皮细胞形态及功能的改变在肺动脉高压形成中的意义。     

Facile regeneration and photocatalytic activity of CuO-modified silver bromide photocatalyst

CuO-modified silver bromide (AgBr/CuO) crystal was successful synthesized by a facile method at room temperature. The physical and chemical properties of AgBr/CuO crystals were carefully detected through X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and Electron spin resonance (ESR) techniques. The photocatalytic activity and stability of AgBr/CuO hybrid were evaluated by photocatalytic degradation of methyl orange (MO) under visible light irradiation. The AgBr/CuO sample exhibited high photocatalytic activity, degrading 92% MO after irradiation for 40 min, which was 3.8 times higher than that of pure AgBr. Both the experimental scavenging results and characterization results revealed that O₂⁻ acts as the main active specie. Based on above, the high photocatalytic performance is mainly attributed to the abundant of oxygen vacancies, and which further generate lots of superoxide radicals. Moreover, the method by using bromide water to rejuvenate AgBr/CuO could well maintain the photocatalytic activity and stability without any environment pollution.     

一种航天器有效载荷新型高功率微波开关

为了抑制空间高功率器件中微放电击穿,本文提出了一种表面多孔结构。通过在器件表面构造该多孔结构,实现对二次发射电子的禁锢,从而减小器件表面二次电子发射系数,提高微放电阈值。通过模拟分析不同金属材料表面的二次电子发射特性,结合波方程和电子动力学理论建立电磁粒子模拟算法,实现不同微观表面微波器件的数值模拟。使用偏置电流法测量不同条件下金属的二次电子发射数据。模拟计算一定功率电平下典型微波开关微放电的物理图像。测量给出不同银表面处理下的二次电子发射特性,并且模拟给出微放电阈值。模拟结果与实验结果吻合良好,证明了表面多孔结构对微放电的有效抑制。     

The preparation of BiOCl photocatalyst and its performance of photodegradation on dyes

The photocatalyst BiOCl was prepared by a facile hydrolysis method and employed to study the phase structure, morphology and optical properties via X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of BiOCl was tested on the degradation of the selected four kinds of dyes under UV and visible light irradiation. The results showed that four dyes molecules could be efficiently degraded over BiOCl under UV light irradiation. Most of all, rhodamine B was thoroughly degraded after visible light irradiation in 60 min and this was ascribed to the dye photosensitization mechanism. The decomposition efficiency of RhB was apparently reduced by adding silver nitrate solution to capture electron of the LUMO orbit. This study demonstrated that electron of the LUMO level of dye molecules played an important role in the dye photosensitization reaction.     

Conventional Electron Microscopy and Electron Holography of Organic Solar Cells

Organic solar cells are a promising route towards large‐area and low‐price photovoltaic systems. The devices are composed of at least two layers: the hole‐transport layer and the electron‐transport layer. The light absorption can occur in one or both layers. At the interface of the layers the excitons are separated into charge carriers, and every layer deals with one type of carrier. Higher efficiencies of the separation process can be obtained by using a mixed layer containing both materials to obtain a very high interface area. Although the structure of the mixed layers used plays a crucial role for the device performance, until now the morphologies have not been elucidated. In order to correlate physical and optical findings with structure and morphology for the materials in question, electron microscopy experiments were performed on the single components as well as on the layer systems. The conventional electron microscope is a poor phase microscope. As consequence, weak‐phase objects like organic molecules have to be stained or imaged under strong defocus to produce an observable contrast. Artifacts caused by chemical staining and the appearance of Fresnel diffraction using the defocus technique represent the main problems of conventional microscopy. These artifacts can be avoided using electron holography. Holograms of ultrathin sections of thin layers composed of organic dye molecules were recorded. Subsequently, the phase images were reconstructed. In this manner, we succeeded in obtaining high‐contrast electron micrographs without applying staining or defocus. In addition, holograms of crystalline C₆₀ and zinc phthalocyanine were successfully recorded. Holography has been shown to be a useful tool to image beam‐sensitive and weak‐phase objects without artifacts.     

Effect of Hydrofiber wound dressings on bacterial ultrastructure

Ionic silver has well-proven bactericidal properties, and silver-containing wound dressings are now widely used to aid in the creation of an antimicrobial environment in wounds. The effect of silver ions on bacterial ultrastructure can best be studied by viewing bacterial cells under a transmission electron microscope (TEM). Bacterial cells of Pseudomonas aeruginosa were incubated within a control dressing (e.g. a non-antimicrobial Hydrofiber dressing) (Hydrofiber is a registered trademark of E.R. Squibb and Sons, L.L.C.) and a silver-containing Hydrofiber dressing, followed by processing for TEM. Liquid cultures, with and without silver, were prepared for comparison. The addition of silver to growing bacterial cultures stopped growth of the cells very quickly. Ultrastructurally, the presence of silver was found to affect both the shape of the bacterial nucleoid and the organization of bacterial DNA. X-ray microanalysis of bacteria from liquid cultures showed the presence of silver within silver-treated cells and the absence of calcium. It is suggested that the presence of available silver ions within the Hydrofiber dressing could lead to the loss of cellular ions, vital for maintaining the structural integrity of the nuclear area.     

En bloc staining available for stereoscopic observation of epoxy resin Quetol 651-embedded thick sections under a high voltage transmission electron microscope.

This method has been devised for easy en block staining for stereoscopic observation of thick sections under a high voltage transmission electron microscope (HVTEM). It uses carbohydrazide as an osmium bridging agent and both osmium tetroxide and uranyl acetate as electron staining agents. Osmium tetroxide-fixed and en bloc-stained tissue blocks are embedded in a Quetol 651 resin mixture. Thick sections (2-3 microns thick) without double staining are observed at an accelerating potential of 300 kV and a tilt angle of +/- 10 degrees by an H-9000 TEM with a side-entry goniometer. Stereoscopic electron micrographs can be obtained.     

Conversion of commercial si solar cells to keep their efficient performance at 15 suns

The screen‐printing method is an economical metallization technique used by most manufacturers of conventional silicon solar cells. This method limits the cells' use under concentrated light owing to high series resistance losses caused, among other reasons, by low metal density in the fingers. This paper describes increasing the finger metal density by electrolytic deposition. The electrolytic deposition of silver is an economical, controllable and readily commercializable deposition method to reduce the front and back metallization series resistance contributions. With an optimized grid design, compatible with 1 sun silicon cell technology, and later electrolytic silver deposition we have obtained cells that maintain their efficiency up to 15 suns. In addition, an analysis of the performance of these cells under uniform and non‐uniform illumination were carried out on n⁺p and n⁺pn⁺ structures. Copyright © 2004 John Wiley & Sons, Ltd.     

Screen-Printable Silver Pastes with Nanosized Glass Frits for Silicon Solar Cells

In this study, silver pastes containing different sizes of glass frits were employed to form the front-side electrodes in order to examine the size effect of the glass frits on the interfacial microstructures between the front-side silver contacts and the n-type silicon emitter layers, which will subsequently affect the electrical performance of silicon solar cells. The interfacial microstructures at the Ag/Si interfaces were investigated by advanced electron microscopy techniques. The transfer length method (TLM) was used to measure the specific contact resistivity of silver electrodes screen-printed on the n-type silicon substrates. The particle size of the glass frits was found to strongly affect the interfacial microstructures and therefore resulted in different specific contact resistivities (ρ _c) of the fabricated silver ohmic contacts. Nanosized glass frits showed excellent etching ability during engineered thermal treatments. The samples made with silver pastes containing microsized glass frits showed a thick residual glass layer at the Ag/Si interface, while the silver paste with nanosized glass frits was found to form an interface with less glass residue, which led to lower resistance after otherwise identical processing.     

Scanning electron microscopic observation of immunohistochemically specified stromal cells following the NaOH maceration method

The present study introduces a method combining immunohistochemistry and a chemical digestion technique applied to scanning electron microscopy (SEM) observation of chemically characterized stromal cells in the myenteric layer of the monkey small intestine. The whole-mount preparation containing the myenteric layer was treated immunohistochemically using small colloidal gold and silver enhancements for detecting a certain type of stromal cell, followed by an alkali maceration method to remove extracellular matrices covering the immunohistochemically stained cells. This method permitted direct SEM observation of the stained stromal cells. Secondary and backscatter electron images clearly visualized the ultrastructure of the immunohistochemically-stained cells and the spatial distribution of the reaction products, respectively. It is suggested that the present method is useful for demonstrating the three-dimensional organization of the chemically specified stromal cells.     

前后向散射特征分析下的白细胞亚型分类识别仿真研究

针对传统流式细胞分析技术中,细胞亚结构形态识别困难以及荧光染色又会改变细胞活性问题的研究需要,依据淋巴细胞和嗜酸性粒细胞形态特征建立了对应的偏心单核细胞模型及双核细胞模型。基于光散射理论下的仿真实验软件,设计了可同时接收细胞前向和后向散射光谱的仿真实验光路,获得了这两种细胞模型下的散射分布图谱,由此建立了不同核质相对折射率下的前、后向散射光光强与442、532、633 nm入射波长关系。通过前、后向散射光谱特征分析,发现在以后向散射光信号为纵轴,前向散射光信号为横轴表征下,淋巴细胞和嗜酸性粒细胞具有明显的分类分区散点特征,从而提出了一种淋巴细胞以及嗜酸性粒细胞的分类识别方法。该散射分类识别计数方法对于设计全光学、非入侵、免标记的血细胞分析仪有一定的潜在应用价值。     

透射电镜电子染色方法的改良

为提高透射电镜生物样品超薄切片的染色效率,在传统染色方法基础上进行改良,使用自制染色装置,在较短时间内完成大批生物样品超薄切片的电子染色。与传统方法相比较省时省药,减少污染机率,电镜观察的超微结构清晰,反差较好。     

Effects of different loads on the surface of silver metal oxide contacts for general-purpose relays

Silver metal oxides have become very popular as contact materials in electromechanical switching devices due to their high resistance to erosion and contact welding. Initially, these materials were developed for contactors and circuit breakers. Investigations on silver metal oxide contacts for general-purpose relays were conducted in order to gain an insight into the effects and failure mechanism of such contacts under specific loads, such as resistive and inrush current loads. It will be shown that contact failures may be influenced by very thin silver layers on the surface of silver metal oxide materials and the behavior of these layers at thermal stress. The silver layers are a result of the mechanical treatment in the production of rivets and the following riveting process. The results support the development of new silver metal oxide materials for general-purpose relay applications.     

Quantifying charging damage in gate oxides of antenna structures for WLR monitoring

A new method to quantify the reliability risk for gate oxide with plasma induced charging damage (PID) is established. Based on existing antenna test methodology the quantity of inflicted damage is expressed in a physical meaningful number by means of a simple model applicable for thick oxides (>5 nm).This model takes trap activation, trap filling, detrapping and also traps generation under constant current test condition (“revealing stress”, “diagnostic stress”) into account. For the corresponding development of the measurable external supply voltage with time an equation is derived. Experimental test data from different oxide thicknesses are fitted to this model equation to obtain its main parameters, the cross section values. These cross section values describe the probabilities for the different trap/detrap processes during stress. Cross section values thus found extend published data for lower electric fields to high electric fields necessary for a fast test.The number of plasma induced traps, which was added to the oxide during wafer processing, can now be determined by applying an electron trapping rate (ETR) test method, and combining it with our dynamic trap generation/filling model. The obtained number of PID related traps opens a path to calculate the corresponding reduction of oxide lifetime. Real measurement data are used to illustrate the method and its applicability to fast wafer level reliability (fWLR) monitoring.     

银迁移对PMZNT基独石电容器电性能的作用机理

研究了内电极中银的迁移对ＰＭＮ－ＰＺＮ－ＰＴ（ＰＭＺＮＴ）基的多层陶瓷电容器电的作用机理。通过微量的银掺杂来探讨在共烧过程银元素由内电极渗透到陶瓷介质中对多层器件造成的影响。借助扫描电显微镜来观察烧成后电极和陶瓷界面处的显微结构。结果表明：银迁移到陶瓷介质中导致介电性能的变化，具体表现为居里点的移动，介电峰值的下降，但并不是简单的单调上升或下降的关系。此外，陶瓷介质的绝缘性能下降，利用缺陷化学方法     

肾组织电镜包埋后银染色技术

应用电镜包埋后银染色技术对肾活检组织进行了观察。发现此技术能清晰地呈现肾小管上皮细胞的基底褶、沿上皮细胞长轴排列的线粒体及小管顶端微绒毛的双层膜结构。我们认为此技术在评价肾小管损伤,例如肾小管坏死、间质性肾炎及移植肾的病理变化中是有价值的。     

大蒜中期染色体银染结构的电镜观察

采用Sato对植物细胞银染的方法对大蒜中期染色体的超微结构进行了研究。结果表明,染色体的切面上有低电子密度区域,该区域中的物质可能与核基质相同。这一结果用常规染色法和NaOH-Bernhard染色法染色得到了证明。本文还对Ag染物质和染色体结构等有关的问题进行了讨论。