Homoharringtonine induces apoptosis of endothelium and down-regulates VEGF expression of K562 cells

Homoharringtonine (HHT) has currently been used successfully in the treatment of acute and chronic myeloid leukemias and has been shown to induce apoptosis of different types of leukemic cells in vitro. Emerging evidence suggests that angiogenesis may play an important role in hematological malignancies, such as leukemia. How ever, whether HHT can relieve leukemia by anti-angiogenesis is still unknown. We investigated the anti-angiogenesis potential of HHT with the human umbilical vein endothelial cell line (ECV304) and leukemic cell line (K562) in vitro. Cellular proliferation was determined by MTT assay and apoptosis was analyzed by flow cytometry. The mRNA expression of vascular endothelial growth factor (VEGF) was assessed by RT-PCR and VEGF protein production was detected by Western blot. Inhibition of cell proliferation and induction of apoptosis by HHT were discovered in ECV304 cells, and appeared in a dose- and time-dependent manner. Also, treatment with HHT caused down-regulation of VEGF mRNA expression in K562 cells in similar dose- and time-dependent manner and inhibition of VEGF protein production in K562 cells in response to the enhancing concentration of HHT. The results demonstrated that HHT could also induce apoptosis in endothelium and down-regulate VEGF expression in K562 cells. In conclusion, we believe HHT has anti-angiogenesis potential and speculate that HHT might exert its anti-leukemia effects via reduction of angiogenesis.     

一类超二次Hamilton系统的周期解的存在性

运用临界点理论中的极小、极大方法得到一类超二次哈密顿系统的周期解的存在性的存在性定理.     

Physical design method of MPSoC

Floorplan, clock network and power plan are crucial steps in deep sub-micron system-on-chip design. A novel di- agonal floorplan is integrated to enhance the data sharing between different cores in system-on-chip. Custom clock network con- taining hand-adjusted buffers and variable routing rules is constructed to realize balanced synchronization. Effective power plan considering both IR drop and electromigration achieves high utilization and maintains power integrity in our MediaSoC. Using such methods, deep sub-micron design challenges are managed under a fast prototyping methodology, which greatly shortens the design cycle.     

长光程薄层光谱电化学技术及应用

提供电子转移反应实验研究的实验装置及技术，依此可获得电子转移数、式电极电势、式异相电子转移速率常数、电子传递系数及还原态和氧化态的扩散系数等一系列重要的电化学参数。还可依此为基础设计出新颖、实用的教学实验。     

课程改革中教师关注阶段理论的研究述评

本文介绍了"关注阶段"的理论架构与评定方法,回顾并分析了它在美国、比利时、荷兰、香港以及澳大利亚等文化情境中的运用与发展.在我国新课程改革背景下进行关注阶段研究不仅有利于我们了解新课程实施情况,而且有助于这一理论自身的发展.     

那西索斯的"倒影"--对杜拉斯"自传性言情书写"的一种解读

“自传性书写”是20世纪以来一种重要的书写方式,法国女作家杜拉斯一生热衷于书写其少女时代的情爱经历,并一次次地将之加以“改写”与“美化”。运用并引申拉康的“镜像场景”及弗洛伊德的“自恋”等精神分析的理论,阐析杜及同类作家热衷于“自传性言情书写”的原因,并试图通过分析杜在真实基础上的“改写”指向,剖析于此透露出的创作动机。     

集群式计算机系统在生物信息学中的应用

1　Introduction　SMP (symmetricmulti processing)andMPP (mas sivelyparallelprocessing)arethetwotypesofstruc tureofparallelcomputing .　Symmetricmulti processingsystemshavemultipleCPUsattachedtothesamebusandsharingRAM .Massivelyparallelprocessingisthecooperated pro cessingofaprogrambymultipleprocessorsthatworkondifferentpartsoftheprogram ,witheachprocessorusingitsownoperatingsystemandmemory .ThechoicebetweenSMPandMPPdependsonthenatureoftheproblembeingsolved .Iftheproblemcanbeeasilypartit…     

对Bermond猜想(32)的一个注记

文章对Bermand猜想（2）加强条件后给出了证明。     

Analysis on Chinese/English Code-Switching in Computer-Mediated Communication Based on Meme Theory

Nowadays,computer-mediated communication(CMC) becomes one of the most convenient ways for people to connect with each other in which Chinese/English code-switching has been frequently used and widely spread.The article will memeticly interpret this language phenomenon based on the authentic examples collected from various kinds of CMC,and point out that the Chinese/English code-switching in CMC is a kind of strong memeplex which includes many different strong memes,resulting in the popularity of Chinese/English code-switching in CMC.     

行政伦理制度化建构之困境探析

行政伦理制度化一直是学界讨论如何建设行政伦理的主要途径。不可否认,制度安排在行政伦理建设中确实具有基础性地位,并且符合我国还处于制度缺失这一阶段的实际国情。但是,制度主义路径是有其缺陷的。只有明确其缺陷,才能更好地探究制度安排路径之外的选择,也才能恰当地利用制度主义路径以避免对这一路径的滥用。作为“复杂人”的公共行政人员,身负各种角色以及多种角色所带来的张力,从而面对一系列的伦理困境,而由角色所带来的困境恰恰是制度安排无法解决的,并且使其缺陷暴露无遗。