共查询到19条相似文献,搜索用时 78 毫秒
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目的:观察尿路致病大肠杆菌和甘露糖在肾小管上皮细胞(PTEC)内的共定位,探讨细菌粘附PTEC的可能机制.方法:在C5a刺激和C5aR拮抗剂(PMX53)作用下,利用激光共聚焦扫描显微镜观察荧光标记的大肠杆菌和甘露糖在原代培养的肾小管上皮细胞中的表达位置.结果:在无任何刺激情况下,PTEC本身表达的甘露糖主要分布在细胞核周围;加入细菌后,甘露糖表达明显升高,并观察到少数细菌与甘露糖共定位;在C5a刺激和等量细菌刺激情况下,PTEC表面粘附的细菌明显增多,且甘露糖的表达明显增多,另外细菌与甘露糖共定位也明显增多;而在PMX53和等量细菌作用下,PTEC粘附的细菌量和甘露糖表达均明显减少.结论:C5a-C5aR信号改变了细胞表面甘露糖的表达,从而影响了细菌在PTEC上的定殖. 相似文献
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<正>近年来,消化内镜新技术发展迅猛,给早期发现胃肠道肿瘤及癌前状态、改善病人预后带来了希望。共聚焦激光显微内镜是最新的内镜技术,由传统电子内镜的头端与共聚焦激光显微镜整合而成,可在进行消化内镜检查的同时对黏膜活细胞下层进行成像,被誉为"光学活检"。不同于一般常规病理检查的内镜表层图像,共聚焦激光显微内镜可获取组织的切面图象,更能清晰观察到组织不同层面的病理状态。共聚焦激光显微内镜具有速度快、准确度高等优势,对于消 相似文献
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激光共聚焦显微镜在磨损表面粗糙度表征中的应用 总被引:2,自引:0,他引:2
磨损是材料常见的表面失效现象,粗糙度是数字化描述材料磨损表面形貌特征的最常用参数.采用激光共聚焦显微镜(LSCM),通过调节物镜倍率、测量视场和过滤参数等,能够得到材料磨损表面的真实形貌,同时能够对磨损表面三维(3D)形貌特征进行精确数字化描述.对常见的粗糙度值0.5~2.0μm磨损表面采用20×物镜扫描测量比较合适;粗糙度小于0.5μm的磨损表面宜采用50×物镜;粗糙度大于2.5μm宜采用10×物镜.对比较规则的磨损表面,采用1~3个物镜视场叠加扫描即可得到比较精确的粗糙度值;对于不太规则的磨损表面,则需要3~5个物镜视场叠加扫描.借助这一手段,采用上述优化参数对Cr5冷轧辊材料磨损各阶段试样表面形貌及粗糙度轮廓曲线进行表征、分析,效果较好. 相似文献
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He-Ne激光对小麦DNA UV-B损伤修复的影响 总被引:7,自引:4,他引:7
研究并分析了He-Ne激光对小麦DNA UV-B损伤修复的影响和机理,以探明激光对UV-B损伤修复的影响途径及机制。结果表明,小麦对增强UV-B辐射损伤具有一定的切除修复能力,切除修复的高峰期发生在UV-B辐射后4~6h内;He-Ne激光主要通过促进小麦的切除修复途径影响小麦对 UV-B损伤的修复,在对损伤DNA的切除及DNA的修复合成两方面均有不同程度的促进作用,其切除高峰期发生在UV-B辐射后4~6h;DNA的修复合成高峰期在辐射后6~7h。 相似文献
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激光扫描共聚焦光谱成像系统需要在光谱带位置处设置一个出射狭缝,通过改变狭缝的宽度和狭缝相对于光谱带的位置,实现对于特定谱段荧光的选择。出射狭缝由两个安装在步进电机上的可移动缝片形成,通过伺服控制的方式,利用ARM芯片生成步进电机的控制信号,并根据编码器和光耦开关提供的位置负反馈进行调整,以实现对于三路通道中狭缝位置与宽度的精确设置。通过实验证明,本文所设计的出射狭缝控制系统能够对缝片位置进行精确设置,实现了同时对样品中不同波段荧光成分进行成像的功能,提高了对于荧光样品观测的灵活性与观察效果。 相似文献
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激光照射牙本质被认为是一种改善粘接效果的新方法。此研究的目的是采用电镜观察Er:YAG激光照射后牙本质的超微结构,评价激光处理牙本质以改善牙体组织和修复体之间粘接性能的可行性。共8颗新鲜拔除的人上颌第三磨牙按照牙合贴面的要求进行牙体预备,拔除牙齿进行牙体预备后接受激光照射,采用电镜观察牙本质的超微结构。分为两组,4颗牙齿为对照组,4颗牙齿为实验组。牙体预备后,对实验组牙齿的牙本质进行Er:YAG激光照射。采用电镜观察牙本质小管,熔融和裂隙等情况。对于实验组,观察结果未见玷污层,牙本质小管清晰。同时,对照组可以见到牙本质小管内有明显的玷污层,因此牙本质小管不清晰。该研究提示Er:YAG激光照射牙本质可以清除牙本质小管内的玷污层,这可能会提高牙体组织和修复体之间的粘接性能。 相似文献
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Electron-beam-induced current (EBIC) and secondary electron image (SEI) modes of a scanning electron microscope (SEM) are
utilized for characterization of charge collection inhomogeneities in hydrogenated amorphous silicon devices. These inhomogeneities
are due to such fabrication defects as substrate surface roughness, pin holes, blistering and lift-off. SEM observations are
correlated with the electrical properties of the devices. Electronirradiation-induced damage in these devices is also investigated
by measuring the EBIC time decay at continuous electron irradiation as a function of both the electron -beam energy and current.
This decay mechanism is based on the formation of electron-irradiation-induced microscopic defects that act as recombination
centers and reduce the lifetime of carriers. 相似文献
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Fluorescence microscopy imaging has developed into an important tool for the study of cell structure and function in cell biology. This non-invasive technique permits the characterization, localization and qualitative quantification of free ions, messengers, pH, voltage and other molecules in living cells. The regulation of cytosolic Ca2+ homeostasis is essential for cells. However, most investigations have used cultured or isolated cells as an experimental model and, consequently, provide only limited insight into the mechanisms that operate in tissue in situ. More useful information could be obtained by studying intact tissue specimens. The calcium dynamics of some tissue specimens, such as arteriole smooth muscle cells, supra cervical ganglia and peripheral nerve bundles, were analysed in this study. Real-time confocal microscopy revealed that individual cells exhibited different [Ca2+]i dynamics and the responses to transmitters/modulators were heterogeneous. It is important that the confocal microscopes have good detection performances, due to the reduction of stray light. We conclude that real-time confocal microscopy is a useful tool for investigating structural and functional changes of cells in living tissues, although suitable tissue-preparation is important for these measurements. 相似文献