搞好期刊管理让期刊更好地为教学科研服务

期刊是教学科研的主要情报来源。从4个方面介绍了如何有效管理期刊文献,以更好地为教学科研服务。     

浅谈查新员与委托人沟通能力的提高

阐述了科技查新工作的一般流程和查新员与委托人沟通的重要性,分析了委托人填写委托书时的心态和常见问题,研究了查新员如何提高与委托人沟通的能力,为查新（特别是高校科技查新）工作的顺利进行提供一定的帮助。     

科技查新中提高查全率的方法探析

分析了科技查新中影响查全率的一些常见因素,从检索途径、检索策略和数据库选择等角度出发,探讨了提高查全率的方法。     

基于人工神经网络的案例检索与案例维护

传统的案例推理系统中,案例检索和案例维护作为两个相互独立的任务分别考虑。而对于案例维护以案例库为纽带,直接为案例检索服务的内在联系没有充分研究。在分别论述案例检索、案例维护,以及人工神经网络在案例推理系统中的应用研究现状基础上,进一步探讨了采用人工神经网络方法实现案例检索和案例维护的整体设计方案,并阐述了其中技术细节。最后,以某产品设计应用为背景,设计并实现了一个反向传播神经网络作为案例检索和案例维护方法,验证了结论的正确性。     

热管的应用探讨

分析热管的特性与发展前景,探讨热管在余热回收和采暖方面的应用.     

Digoxin and ouabain increase the synthesis of cholesterol in human liver cells

Digoxin and ouabain are steroid drugs that inhibit the Na⁺/K⁺-ATPase, and are widely used in the treatment of heart diseases. They may also have additional effects, such as on metabolism of steroid hormones, although until now no evidence has been provided about the effects of these cardioactive glycosides on the synthesis of cholesterol. Here we report that digoxin and ouabain increased the synthesis of cholesterol in human liver HepG2 cells, enhancing the activity and the expression of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the rate-limiting enzyme of the cholesterol synthesis. This effect was mediated by the binding of the sterol regulatory element binding protein-2 (SREBP-2) to the HMGCR promoter, and was lost in cells silenced for SREBP-2 or loaded with increasing amounts of cholesterol. Digoxin and ouabain competed with cholesterol for binding to the SREBP-cleavage-activating protein, and are critical regulators of cholesterol synthesis in human liver cells. Received 10 January 2009; received after revision 11 February 2009; accepted 6 March 2009     

Bile Acids: Chemistry, Pathochemistry, Biology, Pathobiology, and Therapeutics

Bile acids and bile alcohols in the form of their conjugates are amphipathic end products of cholesterol metabolism with multiple physiological functions. The great variety of bile acids and bile alcohols that are present in vertebrates are tabulated. Bile salts have an enterohepatic circulation resulting from efficient vectorial transport of bile salts through the hepatocyte and the ileal enterocyte; such transport leads to the accumulation of a pool of bile salts that cycles between the liver and intestine. Bile salt anions promote lipid absorption, enhance tryptic cleavage of dietary proteins, and have antimicrobial effects. Bile salts are signaling molecules, activating nuclear receptors in the hepatocyte and ileal enterocyte, as well as an increasing number of G-protein coupled receptors. Bile acids are used therapeutically to correct deficiency states, to decrease the cholesterol saturation of bile, or to decrease the cytotoxicity of retained bile acids in cholestatic liver disease.     

中国文学史教学、教材和研究的分合

中国学史的教学、教材编写和研究三之间肛春必然的联系,但又各自属于不同视角的内容。研究更多地注意于学术层面,教材需要考虑到材料的选择、篇幅的大小、观点的平衡等等因素,教学则是以教师为主体并可以带有强烈个人色彩的行为。教学和教材需要学术研究作为基础,但更要在各个方面涉及到“施”与“受”的具体问题。     

关于一类Hopf曲面的同调群

给出一类Ｈｏｐｆ曲面陈类的一个详细计算，并对层上同调群的维数和Ｐｉｃａｒｄ群给出一个具体结果     

基于广播影视资料的图像检索技术研究

本文以国家发改委CNGI项目“基于IPv6的广播影视资料P2P内容存取中闾件系统”为背景,研究了基于内容的图像检索技术。通过对常用颜色和纹理特征提取算法的研究,选择了块RGB均值法、改进参考颜色表法和灰度一平滑共生矩阵法对图像进行特征提取,并使用标准的Corel库建立图像特征数据库,分析和比较这几秤算法单独检索和综合检索的效果。实验结果证明,采用多特征的综合检索比采用单特征的检索具有更高的查全率和查准率,因此采用综合特征检索技术,能够更好地实现对广播影视资料的内容检索。