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1.
Résumé L'administration i.p. de la carbobenzoxy-l-asparagine a retardé la croissance des greffes s.c. d'un lymphosarcome de souris, sensitif à l'action de l'l-asparaginase. L'apparition des tumeurs a été retardée, la période de survie a été prolongée et le poids des tumeurs réduit d'une faÇon significative chez les animaux traités. Le mécanisme de l'inhibition des tumeurs cst considéré.  相似文献   
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Many genes associated with CpG islands undergo de novo methylation in cancer. Studies have suggested that the pattern of this modification may be partially determined by an instructive mechanism that recognizes specifically marked regions of the genome. Using chromatin immunoprecipitation analysis, here we show that genes methylated in cancer cells are specifically packaged with nucleosomes containing histone H3 trimethylated on Lys27. This chromatin mark is established on these unmethylated CpG island genes early in development and then maintained in differentiated cell types by the presence of an EZH2-containing Polycomb complex. In cancer cells, as opposed to normal cells, the presence of this complex brings about the recruitment of DNA methyl transferases, leading to de novo methylation. These results suggest that tumor-specific targeting of de novo methylation is pre-programmed by an established epigenetic system that normally has a role in marking embryonic genes for repression.  相似文献   
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A hexadecapeptide corresponding to positions 59--74 of ubiquitin was synthesized and purified. The peptide was characterized by its mobility in TLC and electrophoresis, amino acid sequence and composition, and molar rotation. The peptide possessed approximately 40% activity compared with native ubiquitin in each of 3 biological assays in vitro: a) thymocyte induction, b) B cell induction and c) elevation of intracellular cyclic AMP levels in sarcoma 180 cells.  相似文献   
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Summary Either by direct GA supply or by release of glycosidic bound GA, pollination causes partial opening of double-stranded DNA in somatic maize kernel tissues, as evidenced by increased Tm profiles. This phenomenon is associated with enhanced RNA and protein production.Acknowledgments: The authors wish to thank Dr.Y. Wurzburger for her aid and advice in extraction and biossay procedure. This research was financed by a grant from the Bar-Ilan Research Council.  相似文献   
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承载供应链管理的客户关系链管理分析与建模   总被引:4,自引:0,他引:4  
指出了客户关系管理的概念不足,以实际例子引出客户关系链的概念,并分析指出客户关系链可以承载供应链的运作管理.利用Markov链对该过程建模,对简单的情况进行了分析和计算,并给出了如果忽略了客户下游信息,企业所受到的损失分析.并同供应链系统作了类比.  相似文献   
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Zusammenfassung Durch Spaltung mit CNBr wurde gezeigt, dass Neurophysin II aus Rinderhypophyse nur eine Methionin-Einheit enthält und dass die N-terminale Sequenz Ala-Met ist.

This work was supported by NIH Grants No. AM-13567, No. AM-10080, by NSF Grant No. GB-17046 and by the City University of New York. The authors are indebted to Dr.L. Abrash for helpful discussion and MissM. Wahrenburg and Mr.V. S. Sapirstein for the assays.

Predoctoral fellow of the Department of Physiology.  相似文献   
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Summary A hexadecapeptide corresponding to positions 59–74 of ubiquitin was synthesized and purified. The peptide was characterized by its mobility in TLC and electrophoresis, amino acid sequence and composition, and molar rotation. The peptide possessed approximately 40% activity compared with native ubiquitin in each of 3 biological assays in vitro: a) thymocyte induction, b) B cell induction and c) elevation of intracellular cyclic AMP levels in sarcoma 180 cells.Acknowledgments. We thank Dr Geoffrey Tregear for helpful suggestions for the synthesis strategy, Dr Jim Burton for guidance with the methods for establishing peptide purity, and Ronald King, Miriam Miller, Jeanette Dilley and Linda Townley for excellent technical assistance. This work was supported by U.S. Public Health Service Grants CA-08748, CA-16889, CA-08415, CA-17085 and AI-12487, and by NCI Contract CB-53868.  相似文献   
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一个用于中小型企业的扩展ERP软件流程集成模型分析   总被引:5,自引:0,他引:5  
在以前工作的基础上,主要讨论了一个将ERP(enterpriseresourceplanning,企业资源规划)、SRM(supplierrelationshipmanagement,供应商关系管理)、CRM(customerrelationshipmanagement,客户关系管理)集成为一体的简化流程模型.论文在界定了几个基本概念的基础上,描述了接触中心的发出流程和接收流程功能,讨论了对ERP软件的流程及核心管理和CRM软件的流程及核心管理思路,研究了对ERP同CRM的关联点,仿照对CRM的分析,对SRM做了类似的分析,最后给出了以关系为企业围墙的扩展ERP简化模型.  相似文献   
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