158 research outputs found

    Speaker\u27s Multiple Choice in Oral Communication

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    講演 国家競争力の強化と公務員人事制度の改革

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    現代漢語中的 "従…到…" 結構

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    推动交叉学科研究 促进生命与医学科学的发展

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    基础研究是国家科技发展的原动力,学科的交融与渗透已经成为当今科学发展的重要趋势,促进交叉学科的健康成长是目前科学界普遍关心的问题之一。分析近百年来获得诺贝尔自然科学奖的300多项成果中,近一半的项目是多学科合作的研究成果,对170多位生理学或医学诺贝尔奖获得者及他们的原创性成果的统计研究发现,具有跨学科知

    Impacts of surface micro-topography on cellular biological responses

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    与常规的细胞体外培养器皿不同,细胞在体内生长时,其微环境并不是简单的平面形式,每一种组织都有其特定的三维微结构。这类具有微结构的微环境是细胞生长、分化的重要调控因子。近年关于基底微拓扑结构影响细胞生长、分化等行为研究的文献迅速增加,研究发现,具有微拓扑结构的基底可改变细胞的铺展、迁移、取向等行为,引导细胞骨架的重排,调控干细胞分化潜能,对于体外组织构建以及医学植入材料的表面处理具有指导性意义。本文就有关基底微拓扑结构影响细胞生物学研究的最新进展进行了综述

    基底力学微环境对干细胞生物学功能的影响

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    目的:干细胞是一类没有分化的多潜能细胞,具有无限自我增殖和分化成多种细胞的能力。干细胞生长的生理微环境称为壁龛(niche),基底硬度、拓扑结构和三维尺寸等物理力学特征决定干细胞的命运。尽管越来越多的证据证明基底力学微环境对干细胞干性及分化具有重要影响,但基底硬度、拓扑结构和三维尺寸单因素及多因素耦合如何影响干细胞的特性及其分子机制还不够清楚。方法:为模拟体内干细胞生长力学微环境,考察不同基

    Differential regulation of stiffness, topography, and dimension of substrates in rat mesenchymal stem cells

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    The physiological microenvironment of the stem cell niche, including the three factors of stiffness, topography, and dimension, is crucial to stem cell proliferation and differentiation. Although a growing body of evidence is present to elucidate the importance of these factors individually, the interaction of the biophysical parameters of the factors remains insufficiently characterized, particularly for stem cells. To address this issue fully, we applied a micro-fabricated polyacrylamide hydrogel substrate with two elasticities, two topographies, and three dimensions to systematically test proliferation, morphology and spreading, differentiation, and cytoskeletal re-organization of rat bone marrow mesenchymal stem cells (rBMSCs) on twelve cases. An isolated but not combinatory impact of the factors was found regarding the specific functions. Substrate stiffness or dimension is predominant in regulating cell proliferation by fostering cell growth on stiff, unevenly dimensioned substrate. Topography is a key factor for manipulating cell morphology and spreading via the formation of a large spherical shape in a pillar substrate but not in a grooved substrate. Although stiffness leads to osteogenic or neuronal differentiation of rBMSCs on a stiff or soft substrate, respectively, topography or dimension also plays a lesser role in directing cell differentiation. Neither an isolated effect nor a combinatory effect was found for actin or tubulin expression, whereas a seemingly combinatory effect of topography and dimension was found in manipulating vimentin expression. These results further the understandings of stem cell proliferation, morphology, and differentiation in a physiologically mimicking microenvironment
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