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1.
医学细胞生物学是医学院校本科生的重要基础学科之一,其实验课程教学工作的改革与创新具有重要意义。本文深入分析了医学细胞生物学实验课程现状,认为课程普遍存在目的不明确、内容不新颖、缺乏整体性、临床联系少等问题。荧光显微成像技术是细胞生物学研究中的关键技术,利用这一技术设计具有整体性的科研实验对于培养医学生操作能力和科研素养具有重要意义。顺铂(cisplatin)为当前肿瘤联合化疗中最常用的药物之一,由于其抗癌机制涉及细胞增殖、细胞凋亡、细胞骨架等一系列细胞生物学知识,且与临床联系紧密,非常适合用于综合性实验设计。实验方案拟使用BrdU染色、Hoechst33258染色及鬼笔环肽染色法,分别检测人肺癌细胞系A549顺铂处理后细胞增殖、细胞凋亡及细胞骨架重排情况。实验完成后,鼓励学生通过查阅文献得出综合的实验结论。希望能够通过科研与教学相融合的方式,更好的激发医学生的学习热情,提高医学生的科研素质,培养全方位的医学人才。 相似文献
2.
Eruch B. Fanibunda 《Journal of biosciences》1995,20(3):355-366
Localization and distribution of non-specific esterases has been studied in intact human dentine, by reflected light microscopy.
The method of specimen preparation described here permits the visualization of optical sections in depth within the specimen
at high optical resolution. Non-specific esterase was found deposited as discrete bands across the tubules. or as droplets,
or as a diffuse microsomal variety in the dentinal tubules and in the interglobular spaces. It was possible to distinguish
the droplet variety from the microsomal variety, of esterase within the same tubule, by means of a novel optical method using
antiflex and differential interference contrast systems of reflected light microscopy. It was found that the coefficient of
reflection of dentine diminished gradually from the enamel to the pre-dentine and was inversely related to the scattering
of light in dentine. This scattering plays an important role in the formation of the image with reflected light microscopy.
The reflected light microscope offers an economically attractive alternative or a supplementary mode of microscopy to the
confocal scanning microscopes for studying intact dentine at varying depths. 相似文献
3.
《Saudi Journal of Biological Sciences》2017,24(7):1626-1630
Both leica microscopic camera system and scanning electron microscopy was used to observe and characterize the feet, back, abdomen, antennae and mouthparts of the Pseudoregma bambucicola from the bamboo, Bambusa multiplex. The possible functions of all the external morphological characteristics of the P. bambucicola were described and discussed in detail, which offers a basis for further enriching the biology, phylogeny and ecological niche of the P. bambucicola. Moreover, the morphological results should contribute to morphological identification and differentiation of the P. bambucicola from other aphids in the same family. 相似文献
4.
《Journal of molecular recognition : JMR》2017,30(3)
Toxicity in amyloidogenic protein misfolding disorders is thought to involve intermediate states of aggregation associated with the formation of amyloid fibrils. Despite their relevance, the heterogeneity and transience of these oligomers have placed great barriers in our understanding of their structural properties. Among amyloid intermediates, annular oligomers or annular protofibrils have raised considerable interest because they may contribute to a mechanism of cellular toxicity via membrane permeation. Here we investigated, by using AFM force spectroscopy, the structural detail of amyloid annular oligomers from transthyretin (TTR), a protein involved in systemic and neurodegenerative amyloidogenic disorders. Manipulation was performed in situ , in the absence of molecular handles and using persistence length‐fit values to select relevant curves. Force curves reveal the presence of dimers in TTR annular oligomers that unfold via a series of structural intermediates. This is in contrast with the manipulation of native TTR that was more often manipulated over length scales compatible with a TTR monomer and without unfolding intermediates. Imaging and force spectroscopy data suggest that dimers are formed by the assembly of monomers in a head‐to‐head orientation with a nonnative interface along their β‐strands. Furthermore, these dimers stack through nonnative contacts that may enhance the stability of the misfolded structure. 相似文献
5.
In crustaceans, grooming behaviors decrease fouling by removing debris from the exoskeleton and body structures; these grooming behaviors improve respiration, sensory reception, movement, and reproduction. Setal morphologies of the following grooming appendages in the decapod crustacean spider crab Libinia dubia are examined including the first pereiopod (cheliped), first, second, and third maxillipeds (mouthparts), and first, second, and third epipods (internal extensions of the maxillipeds). The objective of this study was to describe setal morphologies of these grooming appendages and to elucidate possible functions and efficiencies of setal structures. Spider crabs are hypothesized to have elaborate setal morphologies, mainly for cleaning specialized decorating setae as well as for cleaning inside the gill chamber, which has a higher likelihood of becoming fouled compared to other decapods such as shrimps. Fourteen setal types are documented and included several varieties of serrate and pappose setae as well as simple setae, cuspidate setae, papposerrate setae, and canoe setae. Maxillipodal epipods in the gill chamber are free of fouling, suggesting the setation on the third maxilliped protopod has an efficient functional morphology in removing debris before water enters the gill chamber. Serrate setae may function for detangling and separating structures whereas pappose setae may function for fine detailed grooming. The cheliped is the only grooming appendage that can reach decorating setae and it contains only pappose setae; thus decorating setae is not likely groomed in a manner that would greatly decrease fouling. J. Morphol. 277:1045–1061, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
6.
7.
We used water-soluble styryl pyridinium dyes that fluoresce at the membrane-water interface to study vesicle traffic in endothelial
cells. Cultured endothelial cells derived from bovine and human pulmonary microvessels were incubated in styryl probes, washed
to remove dye from the plasmalemmal outer face, and observed by digital fluorescence microscopy. Vesicles that derived from
plasmalemma by endocytosis were filled with the styryl dye. These vesicles were distributed throughout the cytosol as numerous
particles of heterogeneous diameter and brightness. Vesicle formation was activated 2-fold following addition of extracellular
albumin whereas a control protein, immunoglobulin G, had no effect. Dye uptake was abrogated by labeling at low temperatures
and inhibitors of phosphoinositide-3-kinase (PI 3-kinase). Tyrosine kinase inhibitors (genistein and herbimycin A) prevented
the albumin-induced vesicle formation. Cytochalasin B prevented vesicle redistribution indicating involvement of actin filaments
in translocation of endosomes away from sites of vesicle formation. Styryl dye was lost from cells by exocytosis as evident
by the disappearance of discrete fluorescent particles. N-ethylmaleimide and botulinum toxin types A and B caused cells to accumulate increased number of vesicles suggesting that exocytosis was regulated by NSF-dependent
SNARE mechanism. The results suggest that phosphoinositide metabolism regulates endocytosis in endothelial cells and that
extracellular albumin activates endocytosis by a mechanism involving tyrosine phosphorylation, whereas exocytosis is a distinct
process regulated by the SNARE machinery. The results support the hypothesis that albumin regulates its internalization and
release in vascular endothelial cells via activation of specific endocytic and exocytic pathways. 相似文献
8.
Self‐Doped,n‐Type Perylene Diimide Derivatives as Electron Transporting Layers for High‐Efficiency Polymer Solar Cells 下载免费PDF全文
Zhenfeng Wang Nannan Zheng Wenqiang Zhang He Yan Zengqi Xie Yuguang Ma Fei Huang Yong Cao 《Liver Transplantation》2017,7(15)
Perylene diimide (PDI) with high electron affinities are promising candidates for applications in polymer solar cells (PSCs). In addition, the strength of π‐deficient backbones and end‐groups in an n‐type self‐dopable system strongly affects the formed end‐group‐induced electronic interactions. Herein, a series of amine/ammonium functionalized PDIs with excellent alcohol solubility are synthesized and employed as electron transporting layers (ETLs) in PSCs. The electron transfer properties of the resulting PDIs are dramatically tuned by different end‐groups and π‐deficient backbones. Notably, electron transfer is observed directly in solution in self‐doped PDIs for the first time. A significantly enhanced power conversion efficiency of 10.06% is achieved, when applying the PDIs as ETLs in PTB7‐Th:PC71BM‐based PSCs. These results demonstrate the potential of n‐type organic semiconductors with stable n‐type doping capability and facile solution processibility for future applications of energy transition devices. 相似文献
9.
The NADPH-dependent reduction of some photosynthetic electron carriers in the dark, and the reduction of NADP+ associated
with the glycolytic sequence and the oxidative pentose phosphate pathway in chloroplasts are reviewed. The postulated pathways
of electron transports sensitive and insensitive to antimycin A are also evaluated. It is proposed that the electron flow,
predominantly through cytochrome bf complex, may be also involved in the pathway of NADPH-dependent and antimycin A-insensitive back electron transport. An information
on the chlororespiration in higher plants is also included.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
10.