Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways     

Feng Gao  Xin-yang Hu  Xiao-jie Xie  Qi-yuan Xu  Ya-ping Wang  Xian-bao Liu  Mei-xiang Xiang  Yong Sun  Jian-an Wang 《Journal of Zhejiang University. Science. B》2010,11(8):608-617

Mesenchymal stem cell(MSC)transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90)against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Apoptosis was assessed by Hoechst 33258nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4)and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2)was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,totaI-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.  相似文献   

ZrV_2O_7/Al复合梯度材料制备及特性研究     

王晓芳  李玉红  杨光 《咸阳师范专科学校学报》2010,(4)

采用湿化学/高温煅烧法制备ZrV2O7粉末,并以其和金属Al粉为原料,利用粉末冶金法的堆层技术制备ZrV2O7/Al复合梯度材料。通过XRD、SEM抗热震性实验分析,研究了材料的组织及强度。结果表明:湿化学/高温煅烧法制备的ZrV2O7粉末纯度高;在ZrV2O7/Al复合梯度材料中沿梯度材料纵截面方向的成分梯度过渡明显,各层之间结合紧密。热震性实验表明,ZrV2O7/Al梯度材料的耐高温强度高,各层之间粘结性好。  相似文献   

Impediments to Partnership: A literature review of school‐university links     

Lea Smedley 《Teachers and Teaching》2013,19(2):189-209

Partnership innovations between teacher educators on school and university sites have become ubiquitous. Calls for bridging the theory/practice gap have been answered with reappraisal and restructuring of programs. The literature on the rationale and implementation of a partnership approach has grown steadily since the early 1980s. Praise for measures that promote increased and meaningful interaction between the key players is now almost universal. Ironically, simultaneously, this documentation reveals the challenges as well as the promises of partnership. Clear impediments to the creation and nurturing of partnership have emerged. This paper takes as its principal focus an exploration of the literature that examines the range of barriers encountered by teachers of future teachers.  相似文献   

BookReviews     

Kelly Coate  Michelle Tooher 《Teaching in Higher Education》2013,18(3):347-370

Teachers in American study-abroad programs usually receive little, if any, training before the trip, because ‘teaching is teaching’. The cultural differences between Chinese and American university classrooms, however, affect the students' ability to learn and the teacher's ability to teach in profound ways. Foreign teachers in China require at least a basic understanding of the educational, moral and political dimensions of their classrooms if they wish to maximize the learning potential of their Chinese students. Faculty teaching abroad should be prepared for the politics of their new university department, including management styles that can hamper efforts to acclimatize to the new setting.  相似文献   

不同密实度网衣周围流场数值模拟     

郑艳娜  郭本超  刘德兴  彭海婷 《大连大学学报》2013,(3):50-54

将网衣进简化为平面透空薄板,应用有限体积法求解湍流模型,计算了不同密实度网衣与流场的耦合作用。结果表明,当流速和冲角一定时,密实度越大流速衰减越明显,并且网衣背流区上下两侧的流速增加也越大。随着冲角增大流速衰减越明显,并且阻力系数也随之增大,举力系数先增大后减小,在冲角45°时举力系数最大,在冲角为90度时,举力系数减小为0。  相似文献   

浅析文化休克现象   总被引：1，自引：0，他引：1  

李萍 《昆明师范高等专科学校学报》2003,25(3):52-54

化休克是一种常见的化现象，它经常发生在不同国家之间、不同民族之间、不同群体和不同地区之间的社会化互动过程之中。章从化差异、化变迁以及社会互动的社会学视角切人。对化休克现象产生的原因、形成过程及其关键要素进行分析，并提出几点启示。  相似文献   

传统媒介传播效果衰减成因探析——基于信息社会学的视角     

谢俊贵 《湖南师范大学社会科学学报》2008,37(4):83-86

信息社会形成的严重问题最为显著的就是传统媒介传播效果衰减的问题。深入分析传统媒介传播效果衰减的成因,可以概括为四个方面：即变迁性置换、过密性冲淡、结构性萎缩、集中性削弱。  相似文献   

CD44v6mRNA和HSP70mRNA在胃癌中的表达及研究     

陈秀玲  杨燕君  张江兰  苏华  郜攀峰  薄爱华  张晓丽  邢立强 《河北北方学院学报(医学版)》2005,22(1):35-37

目的:检测CD44v6mRNA和HSP70mRNA在胃癌组织中的表达,探讨CD44v6mRNA和HSP70mRNA在胃癌发生发展中的作用.方法:利用核酸原位杂交技术对39例胃癌组织进行检测.结果:CD44v6mRNA和HSP70mRNA在胃癌组织表达的阳性率都为61.54%(24/39),CD44v6mRNA和HSP70mRNA在高分化管状腺癌与低分化管状腺癌中的表达都有显著性差异(P＜0.05),但HSP70mRNA在胃癌组织的表达与性别、年龄、浸润深度及淋巴结有无转移都无关(P＞0.05),而CD44v6mRNA与淋巴结有无转移有关(P＜0.05).结论:CD44v6mRNA和HSP70mRNA在胃癌组织都有较高的表达,两者均可作为评估胃癌预后的指标.  相似文献   

用计算机模拟方法研究临街建筑对交通噪声的衰减   总被引：1，自引：0，他引：1  

张邦俊  潘仲麟 《科技通报》1993,9(4):230-235

用计算机模拟方法分析了临街建筑对交通噪声的衰减作用.模拟结果表明,建筑环境参数的改变对交通噪声污染程度有明显影响.合理改变建筑环境参数,可显著提高降噪效果.  相似文献   

竖向电渣压力焊施工操作方法特点     

王作俊 《中国科技信息》2006,(7):137-138

竖向电渣压力焊是一种综合效益极好的技术,具有焊接工艺操作简单、速度快、成本低等特点,应在多层和高层框架结构竖向钢筋连接中大力推行.  相似文献