Constituants amers deBrucea amarissima structures des brucéines A,B et C

Summary Evidence is presented for the structures (II a), (II b) and (II c) for the bruceines A, B and C, the bitter principles isolated from the seeds ofBrucea amarissima.

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18ème Communication sur les constituants amers des Simarubacées; 17ème Communication, voir².     

Isocardenolides

Zusammenfassung Ein einfacher Weg zur Synthese eines von zwei möglichen isomeren Cardenoliden wurde entwickelt und die Reaktionsfolge an Hand der Überführung von Pregnenolon in Isocardenolide V gezeigt.

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Steroids and Related Natural Products XXI. For the previous contribution refer to:G. R. Pettit andP. Hofer, Helv. chim. Acta46, 2142 (1963).

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A preliminary account of this study was presented (December 1963) at the VI. Pan-American Congress of Pharmacy and Biochemistry, Mexico City (Mexico).

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This investigation was supported by PHS Research Grants CY-4074 (C3) to CA-04074-06 from the National Cancer Institute, Public Health Service.     

On the activity of neurosecretory cells in the flesh-flySarcophaga bullata

Résumé L'activité des cellules neurosécretrices dans le cerveau de la femelle deSarcophaga bullata est en corrélation avec le développement des larves dans la femelle et leur position.     

AAV serotype 2 vectors preferentially integrate into active genes in mice

Recombinant adeno-associated virus serotype 2 (rAAV2) is a promising vector for gene therapy because it can achieve long-term stable transgene expression in animals and human subjects after direct administration of vectors into various target tissues. In the liver, although stable transgene expression primarily results from extrachromosomal vector genomes, a series of experiments has shown that vector genomes integrate into host chromosomes in hepatocytes at a low frequency. Despite the low integration efficiency, recent reports of retroviral insertional mutagenesis in mice and two human subjects have raised concerns about the potential for rAAV2-mediated insertional mutagenesis. Here we characterize rAAV2-targeted chromosomal integration sites isolated from selected or non-selected hepatocytes in vector-injected mouse livers. We document frequent chromosomal deletions of up to 2 kb at integration sites (14 of 14 integrations, 100%; most of the deletions were <0.3 kb) and preferred integration into genes (21 of 29 integrations, 72%). In addition, all of the targeted genes analyzed (20 of 20 targeted genes, 100%) were expressed in the liver. This is the first report to our knowledge on host chromosomal effects of rAAV2 integration in animals, and it provides insights into the nature of rAAV2 vector integration into chromosomes in quiescent somatic cells in animals and human subjects.     

粗粒度并行遗传算法收敛性分析及优化运算

提出了一种新型的粗粒度并行遗传算法(CGGA)，该算法利用多个子种群基于不同的编码方式进行进化计算．首先各子群体独立进行交叉、变异和选择遗传操作，每代进化后迁移算子被引入用来进行种群问的信息交流，迁移算子将各个子种群的最优个体替换相邻种群最差个体后继续进化．基于时齐遍历马尔可夫链理论，给出了CGGA各个子种群的概率转移矩阵与其进化概率转移矩阵，证明了以概率1全局收敛．对典型的测试函数CGGA进行了求解．仿真结果表明，本算法的收敛性能优于经典遗传算法(CGA)，可以有效解决CGA的过早收敛问题．     

多孔介质中的大尺度多相渗流

在许多工业和环境应用中，不同时空尺度上的多孔介质中的多相渗流都是一个非常重要的过程。因此，了解确定微尺度上的多相渗流和其反应传递过程，并描述其宏观条件下的运动现象是很必要的。目前描述宏观下的多相渗流现象都是基于由达西定律经验公式得到的毛管压力一饱和度一相对渗透率关系式。然而，这些经验模型并不能完全反映实际的物理现象，尤其是大尺度和非均质介质中渗流问题。