人精子甘露糖受体的胶体金标记电镜观察

本文首次报道人精子甘露糖受体（ＭＲ）的电镜标记技术和初步观察了，采用甘露糖化牛血清白蛋白（ＤＭＡ，Ｓｉｇｍａ，Ａ８３０３）结合１０ｎｍ胶体金制备探针，标记获能前后精子和甲醇处理或Ａ２３１８７诱导顶体反应（ＡＲ）的精子。结果表明，甲醇处理后ＭＲ表达顶体区质膜表面，活精子在ＡＲ过程中以不同方式表达ＭＲ活性；ＭＲ定位于：１．ＡＲ早期的精子顶体区质膜表面。２．ＡＲ期间精子的顶体小泡表面，顶体内膜及顶体基质     

小鼠精子附睾成熟过程中Ca^2＋及Ca^2＋—ATPase的研究

利用焦锑酸钾方法和电镜酶组织化学定位方法，研究了小鼠精子在附睾成熟过程中的Ｃａ＾２＋及Ｃａ＾２＋－ＡＴＰａｓｅ变化。结果发现：附睾头中的精子内元Ｃａ＾２＋或极低，而Ｃａ＾２＋－ＡＴＰａｓｅ活性极强，可能是由于Ｃａ＾２＋－ＡＴＰａｓｅ的作用将Ｃａ＾２＋从精子内排出了精子外；在附睾体中，精子Ｃａ＾２＋－ＡＴＰａｓｅ活性降低，而Ｃａ＾２＋浓度迅速上升，并且发现Ｃａ＾２＋来自于附睾管细胞；到了附睾尾部，精     

珍贵绢丝昆虫--天蚕精子的超微结构及其在生殖管道中的变化

电镜观察结果表明,天蚕真核精子分成棒状头部和细线状尾部二部分,在睾丸中以精子束存在,核呈半圆形、大半圆形或椭圆形,鞭毛内部由线粒体衍生物和微管系统（轴丝）构成,微管系统由９根副微管９根双微管和２根中央微管组成,属典型的９＋９＋２构型;顶体、核和鞭毛部质膜上均覆盖有片层外长物和网状外长物。无核精子细长,其头尾部形状差异不明显,在睾丸中也以精子束存在,鞭毛内部嵋线粒全衍生物和微管系统构成,微管系统亦属     

小鼠精子获能及顶体反应过程中Ca^2＋及Ca^2＋—ATPase的研究

利用焦锑酸钾电镜定位Ｃａ＾２＋的技术，及铅捕获法定位细胞Ｃａ＾２＋－ＡＴＰａｓｅ的技术，研究小鼠了获能及顶体反应过程中Ｃａ＾２＋及Ｃａ＾２＋－ＡＴＰａｓｅ的变化，结果表明，获能前精子顶体囊外缘有Ｃａ＾２＋分布，顶体膨胀时，Ｃａ＾２＋消失，开始顶体反应时，顶体外膜，顶体囊泡及顶体后区有Ｃａ＾２＋分布，顶体反应后，仅顶体后区有Ｃａ＾２＋分布精子尾部线粒体及轴丝始终有Ｃａ＾２＋分布。     

彩虹明樱蛤精子发生的超微结构

应用透射电镜观察彩虹明樱蛤的精子发生过程,描述了从精原细胞发育成为成熟精子过程中的超微结构变化。主要表现在染色质以颗粒状形式浓缩和分散;高尔基体分泌的前顶体颗粒逐渐融合形成前顶体囊、前顶体最终发育成为顶体;线粒体逐渐融合形成精子中段;细胞核的拉伸和旋转以及中心体和鞭毛的形成等。在初级精母细胞阶段,同源染色体经历了联会复合体形成和解体的变化。前顶体颗粒和中心粒结构在精原细胞期就已经存在。根据染色质和顶体发育的变化特点将精细胞分为6个时期,并描述了各期精细胞的超微结构特点。彩虹明樱蛤成熟精子属于原生型,由头部、中段和尾部组成。     

黄鳝精子入卵过程扫描电镜观察

利用扫描电镜技术对黄鳝(Monopterus albus)精子、成熟卵的形态以及精子入卵过程进行观察,结果显示:黄鳝精子为鞭毛型,无顶体,由头部、颈部和尾三部分组成,全长约13.02μm;成熟卵较大,直径约1.67~2.83 mm,表面均匀分布微小棘状突起,动物极有一卵膜孔,卵膜孔底部为一受精孔,卵膜孔周围有12~13条沟嵴;在28~29℃时,精子10 s内可完成入卵过程,同时受精孔向外分泌大量絮状物阻止其他精子进入;约45 s后受精孔外精子完全解体;2 min后絮状物完全转变为特殊的盖状受精栓。对精子、卵及受精孔进行测量,结合扫描电镜观察结果,推测黄鳝受精方式为单精受精。     

瘤头鸭精子的超微结构

瘤头鸭精子分为头部和尾部。头部包括顶体和细胞核。顶体位于最前方。顶体下腔中有顶体突起。细胞核棒状,位于顶体之后。尾部由颈段、中段、主段和末段构成。颈段含有近端中心粒和远端中心粒。近端中心粒位于核后端的植入窝中。远端中心粒紧随其后。中心粒的外方有线粒体鞘。中段的中央结构是前轴丝(轴丝的前体),它与前方的远端中心粒相连。前轴丝的外方也有线粒体鞘。主段的中央结构是轴丝,它接于前轴丝的后端。轴丝外方有一圆筒状鞘。末段只有轴丝而无圆筒状鞘。整条精子外方包有细胞质膜。     

男性不孕症患者精子超微结构异常的电镜诊断

对63例男性不孕症患者的精子做了电镜超微结构观察,并做了与之对应的光镜及常规检查。除11例为死精症外,52例均为精子结构异常。52例中40例为头部异常,12例尾异常。头部异常主要为无顶体、顶体发育不良和染色质发育不良,尾异常主要为2＋9＋9结构异常及接柱异常。结果显示精子电镜超微结构检查能很好地避免误诊,并对精子结构异常的种类做出准确的诊断。     

激光辐射对绵羊精子细胞内外酶活性的影响

Ilina用氦氖激光照射公猪精液,Sato等用氪激光照射人精液,发现激光能提高精子活率,[2]还证明激光对精子游速无明显影响.本研究用氦氖激光照射绵羊的离体精液,根据激光照射后精子细胞内外酶活性的变化,试从分子水平上来研究激光对精子细胞的辐射效应,以探讨激光刺激动物生殖细胞的机理,为激光诱变育种提供理论依据.一、材料和方法     

Distal surface of the rat ruffle-ended ameloblasts at the stage of enamel maturation observed by scanning electron microscopy

Distal surface of the rat ruffle-ended ameloblasts was observed by high resolution scanning electron microscopy. Specimens fixed by perfusion with 0.5% formaldehyde and 0.5% glutaraldehyde were decalcified with ethylenediamine tetraacetic acid and freeze-fractured using dimethyl sulfoxide. They were treated with 0.1% osmium tetroxide for 96 hr to remove excess cytoplasmic matrices, dehydrated, and critical-point dried. The present method was useful for observing both surface and intracellular structures simultaneously. The dense lamina lining the distal surface of the ruffle-ended ameloblasts having been dissolved in this preparation, the surface was clearly demonstrated in three dimensions under SEM. The surface was characterized by a complex labyrinth formed by protrusion and invagination of the plasma membrane. At high magnification, two kinds of minute granules are visible: small and larger granules measured as 10-20 nm and 70 nm in diameter, respectively. The former were more numerous than the latter. Furthermore, microfibrils connecting the protrusions of the plasma membrane were observed on the distal surface. The small granules probably connect the dense lamina with the distal surface of the ameloblasts. In addition, a denuded area free from the granules was sometimes recognized on the distal surface. These surface structures of the distal end of the ameloblasts appeared to be concerned with the enamel maturation.     

Dynamics of the mammalian sperm membrane modification leading to fertilization: a cytological study

Fertilization occurs when the sperm penetrates the egg, resulting in the combination of paternal and maternal genomes for the propagation of generations. To perform the task, the mammalian sperm membrane system, constructed during spermatogenesis, undergoes biochemical and cytological modifications. In this review, the following three points are discussed: (i) the nature of the acrosomal membrane disclosed by various types of microscopy, including transmission electron microscopy and the recently developed high-resolution fluorescence microscopy, (ii) the nascent acrosomal membrane dysfunction during acrosome biogenesis and (iii) the modification of the sperm membrane during sperm-egg interaction.     

In utero changes of the plasma membrane in the head region of the rat spermatozoa

The plasma membrane of the head of the rat spermatozoa was observed by deep-etch, surface replica, and freeze-fracture methods. The spermatozoa were from three experiments: 1) incubation in Hepes buffer, 2) natural coition, and 3) insemination. The spermatozoa used for experiments 1) and 3) were obtained from the ductus deferens. No change in ultrastructure was observed in the incubation experiment. Randomly oriented rows of particles were observed on the plasma membrane of the ejaculated spermatozoa in the deep-etch replicas. The surface replicas showed a similar structure on the plasma membrane. The surface of the inseminated spermatozoa was smooth. This study shows that the plasma membrane changes in the uterus.     

Microtribology and Friction‐Induced Material Transfer in WS2 Nanoparticle Additives

The tribological behavior of platelet and nested colloidal particles of tungsten disulfide was studied using the surface forces apparatus, atomic force microscopy, lateral force microscopy, and Auger spectroscopy. Shear‐induced material transfer from the colloidal particles to the surfaces was shown to be a dominant factor in the tribological behavior observed for both structures. An ultrathin, ordered layer was observed when nested particles were sheared, while WS₂ platelets produced a rough and disordered transfer layer, with substantially inferior lubricating properties.     

SiO_2胶体对磁头表面污染分析

在发生磁头表面污染的清洗工序收集了被污染的样品并提取了水样,将检查后表面无污染的磁头通过清洗用水浸泡准备了模拟样品。用原子力显微镜和超级扫描电子显微镜对两种磁头样品形貌进行观察,结果表明,污染物由20nm左右的纳米微粒组成;采用飞行时间二次离子质谱仪、透射电子显微镜和能量损失谱仪表征了两种样品的污染物成分和微观结构,确定出两种样品污染物同为SiO2;用电感耦合等离子体质谱仪检测污染发生时清洗用水水样,发现Si含量严重超标达到16 600μg/L;在讨论了SiO2在水中存在的形式后,推断出SiO2胶体造成水处理过程中的反渗透膜和离子交换树脂失效,使大量SiO2胶体流入清洗用水造成磁头表面污染。     

粘着力对化学机械抛光芯片分子去除机理影响的数学模型

基于芯片/磨粒/抛光垫的微观接触力平衡关系,建立了考虑抛光垫/磨粒大变形和粘着力效应的微观接触模型,模型预测结果表明：对于Cu和SiO2芯片而言,粘着力对磨粒所受外力具有重要影响作用;考虑粘着力的情况下,单个磨粒压入芯片的深度比未考虑粘着效应时,最大为原来的2倍和4倍。然而,即使考虑粘着效应时,磨粒压入芯片的深度仍然在分子量级。因此,认为CMP材料的去除机理为单分子层去除机理,为深入研究CMP材料原子/分子去除机理提供了一定的理论指导。     

激光熔覆纳米WC/Ni60涂层水润滑磨损组织变化特征

采用优化后的激光熔覆工艺参数,以团聚纳米晶WC颗粒为增强相,在45钢表面熔覆上一层纳米WC增强Ni基合金复合涂层。采用SEM、EDS、X-ray等技术手段,对涂层表面磨损前和磨损后的显微组织和元素含量进行了分析研究,得到以下结论：磨损表面在摩擦应力作用下,发生了明显的相变特征,其中涂层中碳化物形成元素的位错扩散发生明显...     

Investigation of the Surface Removal Process of Silicon Carbide in Elastic Emission Machining

Elastic emission machining (EEM) is a precise surface preparation technique, which uses chemical reactions between the surfaces of the workpiece and fine powder particles. The purpose of this study is to clarify the surface removal process of silicon carbide (SiC) in EEM. A SiC sample with a periodic step-bunched structure was prepared as the initial surface and was flattened by EEM. Optical interferometer and atomic force microscopy (AFM) observations show that the topmost areas on the periodic step-bunched structure in contact with the powder particles are preferentially removed and surface protrusion is gradually reduced as removal depth increases. Moreover, power spectral density analyses reveal that the surface is smoothed in the spatial wavelength range from 0.07 μm to 10 μm.     

Periciliary structure of developing rat photoreceptor cells. A deep etch replica and freeze substitution study

The purpose of this study is to identify the morphological machinery for selective transport of proteins required in the outer segments of the rat photoreceptor cell. As a first step, the three-dimensional architecture of the periciliary region and its developmental changes were examined. Freeze-deep-etching and freeze-substitution methods combined with rapid freezing technique were used. The apical surface of the inner segment was swollen and partially enclosed the base of the connecting cilium in early postnatal stages, so that the basal region of the connecting cilium was inevitably surrounded by a groove. However, a specialized periciliary ridge complex as seen in frog photoreceptor cells has never been observed in rat photoreceptor cells. The cytoplasmic surface of the plasma membrane of the apical inner segment in the vicinity of the connecting cilium was covered with loose fine filaments. However, it was unlikely to be a possible structural candidate for selective transport of membrane proteins. This study also revealed the interior structure of the connecting cilium. Actin filaments in the distal axonem formed a complicated meshwork together with an unknown substance. Since S1 decorated filaments were not detected in the middle region of the connecting cilium, actin filaments at the base of outer segment seem to be independently polymerized locally from G-actin that is transported from the inner segment.     

粉末样品的原子力显微镜研究方法

本文提出了用纯净水对粉末样品充分湿润以后,把粉末样品置于空气中,待其自然蒸发到样品表面只有分子结合水以后再进行AFM扫描成像的粉末样品原子力显微镜研究方法。通过分析实验过程发现,原始粉末样品颗粒表面大量的过剩电荷被分子结合水层中和,解决了扫描过程中颗粒易于粘到针尖上的问题;颗粒间存在的分子结合水与毛细管水,使颗粒之间结合牢固,解决了扫描过程不稳定的问题。实验结果表明,该法获得的粉末样品形貌图清晰真实,且具有简单易行,适用范围广的特点。另外,该方法提出了一种针尖在大气中振动．而被扫描样品在液体中的复合扫描环境,具有进一步深入研究和推广的价值。     

多层铜布线表面CMP后颗粒去除研究

针对目前清洗技术存在的问题进行了详细分析,研究了微电子材料表面污染物的来源及其危害,并介绍了表面活性剂在颗粒去除方面的作用。研究了化学机械抛光(CMP)后Cu布线片表面的颗粒吸附状态,分析了铜片表面颗粒的吸附机理。采用非离子表面活性剂润湿擦洗方法,使Cu表面的颗粒处于易清洗的物理吸附状态。利用金相显微镜和原子力显微镜(AFM)在清洗前后进行对比分析,实验采用聚乙烯醇(PVA)刷子分别对铜片和铜布线片进行清洗,发现非离子界面活性剂能够有效去除化学机械抛光后表面吸附的杂质,达到了较好的清洗效果。