信号流图的扩展及其应用

将信号流图扩展到状态空间构成所谓向量流图,用公式可实现组合系统规范化;按工答过程绘制信号流图构成所谓过程流图,可对系统组件作深入的分析。     

Cloning, construction of prokaryotic expression vector and expression ofEscherichia coli cytosine deaminase gene

Cytosine deaminase gene ofEscherichia coli strain H-30 was cloned, and its initiation codon of ‘GTG’ was mutated to ‘ATG’ by PCR. Prokaryotic recombinant expression vector pBV220-CD was constructed. Clone with high enzyme activity were selected by detecting their specific activity of cytosine deaminase. 5-FC(5-FC, 5-fluorocytosine) could induce the lethal toxicity to cells containing active CD gene. DNA sequence analysis indicated that there were 16 altered bases and 5 of them resulted in the alteration of amino acids in predicted peptide by comparing DNA sequence of the clone H-30-CD-11 with high enzyme activity with CD gene reported in Gene Bank.     

Research advances in gene therapy for Parkinson's disease

During the long period of time when people have been seeking for an effective therapeutic method for PD, the gene therapy has shown greater and greater advantages over other methods. It can be performed mainly in two ways: ex vivo and in vivo. With the former, TH gene as well as some neurotrophic factor genes (such as GDNF, BNDF genes) can be invited to some cell lines or primary cells thus forming engineered cells and then implanting them into brain. While with the latter, viral vectors including HSV-1, Ad, AAV that can be utilized to construct recombinant viruses, or non-virus vectors can be used to delived DNA into brain directly. The present review summarizes the recent research advances in the gene therapy for PD, and it is reasonable for us to predict a notable progress in prevention and treatment for PD in the next decade.     

Construction of High Level Expression Cell Lines of Erythropoietin *

Ｅｒｙｔｈｒｏｐｏｉｅｔｉｎ（ＥＰＯ）ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｒｅｇｕｌａｔｏｒｙｆａｃｔｏｒｓｄｕｒｉｎｇｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｍａｍｍａｌｉａｎｅｒｙｔｈｒｏｃｙｔｅ,ａｃｔｉｎｇｍａｉｎｌｙｏｎｔｈｅｅｒｙｔｈｒ...     

利用初等行变换求极大无关组的一些条件

本文讨论利用初等行变换求行向量组的极大线性无关组的方法,澄清一些线性代数教学用书中存在的一种模糊认识,并给出修正后的方法。     

广义块Pick型矩阵和带导数的Nevanlinna-Pick矩阵插值问题

建立了广义块Pick型矩阵和块Toeplitz矩阵之间的一种等价关系,并将其用于求解一类带导数的Nevanlinna-Pick矩阵插值问题     

腺病毒载体介导胸苷激酶基因/ACV对大鼠脑胶质瘤的离体和活体杀伤作用

建立缺陷型重组腺病毒载体介导的胸苷激酶基因治疗系统（Adtk／ACV）,进行离休和活体治疗大鼠C6脑胶质瘤研究．将质粒pAdtk与pJM17共转染腺病毒包装细胞──293细胞,同源重组后制备纯化的Adtk并以PCR证实;Adtk对离休C6细胞的杀伤作用随着Adtk滴度和ACV剂量增加而增强,并有旁观者效应,而未转染C6细胞和AdLacZ转染C6细胞均未被杀伤;扫描电镜下见Adtk／ACV处理的细胞呈明显病理改变;ACV可有效杀伤Adtk／C6细胞．在大鼠脑立体定向仪引导下于右额叶接种2×106个C6细胞,分别于第3,6,8和10天原位注射Adtk,同时腹腔注射ACV（100mg／（kg·d-1））,3d组、6d组、8d组大鼠成活期在90d以上,组织学检查未发现肿瘤细胞．10d组成活期（28．5±4．6）d,而C6未治疗组和AdLacZ／ACV治疗组成活期分别为（1．8±3．1）d和（14．0±2．2）d．本文建立的Adtk／ACV在离体和活体水平对大鼠C6脑胶质瘤有强烈的杀伤作用,效果确实,应用方便,ACV价格便宜,有潜在临床应用价值．     

APT 理论的非参数解释

本文用非参数回归方法中的核函数法和最近邻法来解释ＡＰＴ理论．通过不同核函数的选择和最近邻估计中参数的变化以及鲁棒性回归的辅助解释,来寻找ＡＰＴ理论较好的非参数解释．     

逐步回归分析的拓展

给出一种方法,在逐步回归后,使每一前进（后退）步为一单元步,用Ｆ检验来判别这单元步的去留,使回归式子比逐步回归纳入更多的解析变量,同时能减低向后消元法产生多重共线性的可能性．     

R^3中一类二次齐次向量场的拓扑结构

讨论了Ｒ３中的二次齐次向量场Ｑ（ｘ）的拓扑结构．当它只有孤立奇点时,利用向量场ＷＱ（ｘ）的相图,得到Ｑ（ｘ）的轨线共有１２种不同的拓扑等价类．