基于NMF技术探寻早期AD基因表达调控网络

利用非负矩阵分解(NMF)技术,依据加强算法的稀疏性对患早期阿尔茨海默症(AD)样本的基因表达数据进行分析,提取对疾病早期诊断具有重要意义的显著基因,样本分类实验结果证明了算法的有效性.在此基础上,结合与炎症反应有重要关系的NF-κB等基因初步建立了与早期AD密切相关的基因表达调控网络结构图,为AD致病机理的探询、早期诊断与治疗等提供了有益的途径和方法.     

系列食品微生物多糖的高黏度发酵关键技术

比较产热凝胶菌株生长和合成多糖阶段的能量代谢差异,特别是能量耗散的差异,构建了土壤杆菌ATCC 31749产热凝胶的代谢途径.研究产生能量代谢差异的原因及其影响因素,利用分子生物学技术和生物信息学工具,构建了土壤杆菌电子呼吸链的传递途径.研究高密度培养、高强度生产的两步法微生物多糖发酵工艺.在预备罐中以低C/N营养条件,实现产多糖微生物的快速高密度培养.在发酵罐中稀释细胞后以高C/N营养条件高强度生产微生物多糖.研制工业规模下适用于高黏度发酵的高效生物反应器.以结冷胶为高黏度发酵模型体系,研究该反应器在冷模条件下的传质、混合和流变行为特征,设计了新型高效生物反应器,放大至50 m3并应用于结冷胶发酵生产实践中.     

Wnt/β-catenin信号途径在DDR和氧化应激中的作用

Wnt/β-catenin信号途径在调控基因表达与DNA损伤反应(DNA damage response,DDR)中具有重要作用.氧化应激是导致DNA损伤的主要原因,且可以影响Wnt信号.首先总结了Wnt/β-catenin信号途径和DDR,然后综述了Wnt/β-catenin信号途径在DDR和氧化应激中的作用及分子机制,以期为DNA修复缺陷性肿瘤提供更有效的治疗策略.     

植物中钙解码机制的研究进展

Ca2＋作为重要的第二信使,在植物生长发育中起着非常重要的作用．目前已经鉴定的植物Ca2＋传感器蛋白有：钙调素（CaM）、类钙调素蛋白（CMLs）、钙依赖型蛋白激酶（CDPKs）和类钙调磷酸酶B亚基蛋白（CBLs）及其互作蛋白激酶（CIPKs）,这些传感器蛋白多以基因家族形式存在,并且在植物中能够形成错综复杂的钙离子信号传递网络系统．主要从植物Ca2＋传感器蛋白的生化特性、生理功能和靶蛋白3个方面,综述了植物解码钙信号机制的最新研究进展．     

Regulation of insulin receptor function

Resistance to the biological actions of insulin contributes to the development of type 2 diabetes and risk of cardiovascular disease. A reduced biological response to insulin by tissues results from an impairment in the cascade of phosphorylation events within cells that regulate the activity of enzymes comprising the insulin signaling pathway. In most models of insulin resistance, there is evidence that this decrement in insulin signaling begins with either the activation or substrate kinase activity of the insulin receptor (IR), which is the only component of the pathway that is unique to insulin action. Activation of the IR can be impaired by post-translational modifications of the protein involving serine phosphorylation, or by binding to inhibiting proteins such as PC-1 or members of the SOCS or Grb protein families. The impact of these processes on the conformational changes and phosphorylation events required for full signaling activity, as well as the role of these mechanisms in human disease, is reviewed in this article. Received 3 August 2006; received after revision 1 December 2006; accepted 8 January 2007     

Optimization of the cellular import of functionally active SH2-domain-interacting phosphopeptides

Phosphopeptides interacting with src homology 2 (SH2) domains can activate essential signaling enzymes in vitro. When delivered to cells, they may disrupt protein-protein interactions, thereby influencing intracellular signaling. We showed earlier that phosphopeptides corresponding to the inhibitory motif of Fcγ receptor IIb and a motif of the Grb2-associated binder 1 adaptor protein activate SH2-containing tyrosine phosphatase 2 in vitro. To study the ex vivo effects of these peptides, we have now compared different methods for peptide delivery: (i) permeabilization of the target cells and (ii) the use of cell-permeable vectors, which are potentially able to transport biologically active compounds into B cells. We found octanoyl-Arg₈ to be an optimal carrier for the delivery of phosphopeptides to the cells. With this strategy, the function of cell-permeable SHP-2-binding phosphopeptides was analyzed. These peptides modulated the protein phosphorylation in B cells in a dose- and time-dependent manner. Received 27 July 2006; received after revision 4 September 2006; accepted 18 September 2006     

机顶盒硬件接口信号的研究及应用

数字电视机顶盒的技术含量非常高,它集中反映了多媒体、计算机、通信技术和网络技术的发展水平.本文对其接口信号进行的分析比较研究,对于数字电视信号的高质量传输,硬件设备的合理配置以及充分发挥音视频设备的最大效能,具有重要的实践意义.     

Plant grafting and its application in biological research

Grafting is widely used for various aspects of plant biological research. We reviewed grafting methods and graft development processes for herbaceous plants. We introduced also methods of investigating the development of graft union and compatibility, and the application of grafting in understanding translocation of substances and long-distance signaling in plants.     

基于非负矩阵分解技术探寻早期阿尔茨海默症基因表达调控网络

本文利用非负矩阵分解(NMF)技术,依据加强算法的稀疏性对患早期阿尔茨海默 症(Alzheimer’s Disease,AD)样本的基因表达数据进行了分析,提取了对疾病早期诊断具有重 要意义的显著基因,样本分类实验结果证明了算法的有效性。在此基础上,结合与炎症反应 有重要关系的 NF-κB 等基因初步建立了与早期 AD 密切相关的基因表达调控网络结构图, 为 AD 致病机理的探询、早期诊断与治疗等提供了有益的途径和方法。