The processing and presentation of endogenous and exogenous antigen by Schwann cells in vitro

The expression of major histocomatibility complex class II in vitro and in vivo by Schwann cells indicates a potential facultative role of Schwann cells in the presentation of antigen to neuritogenic T cells during inflammatory demyelinating neuropathies. Using a T cell proliferation assay, this study demonstrated that processing and presentation of endogenous and exogenous antigen by Schwann cells influences T cell proliferation. Statistical analysis of proliferation and its relation to processing and presentation of antigen by Schwann cells had not been previously addressed. Different combinations of factors including treatment of cultures (untreated, irradiated or fixed), concentration of exogenous antigen (0 or 40 μmg/ml), the presence of interferon-γ and the timing of exogenous antigen addition influence the proliferation P₂-specific, non-mammalian protein ovalbumin-specific T cell lines and naive T cells. Received 25 July 2002; received after revision 9 September 2002; accepted 7 October 2002     

几种野生豆科锦鸡儿属(Caragana Fabr.)植物离体培养过程中器官分化和内源植物激素含量的关系

通过对内蒙古自治区三种野生豆科锦鸡儿属植物——柠条(C.korshinskii)、狭叶锦鸡儿(C.stenophylla)和黄刺条(C.frutex)的组织培养,从它们的上胚轴、下胚轴(或幼茎)上直接诱导出芽并获得了幼苗,从后两种植物的胚轴(或幼茎)的愈伤组织中也诱导出芽,并使其生根,获得再生小植株。本文着重研究了激素对这三种植物的愈伤组织生长和分化的影响,并对脱分化和已有器官分化的两个时期的愈伤组织的内源生长素和细胞分裂素的活性进行了测定,发现两个时期愈伤组织中内源激素系统有明显不同,推测这种变化与愈伤组织的诱导和分化有一定的关系。     

Experimential evidence for endogenously programmed differential migration in the blackcap (Sylvia atricapilla)

Female hand-raised blackcaps (Sylvia atricapilla) held in constant conditions (except for simulated seasonal changes in photoperiod) showed significantly more, and significantly longer, autumnal migratory activity as well as significantly later initiation of spring migratory activity than males from the same population (including siblings) held under identical conditions.This research was supported by the Alexander von Humboldt Foundation (Terrill) and the Deutsche Forschungsgemeinschaft (Berthold).     

Partial purification of an endogenous elicitor from suspension-cultured cells of red bean,Vigna angularis

Brief irradiation with a germicidal UV lamp of cells of red bean,Vigna angularis, cultured in suspension in a quartz flask caused the release into the culture medium of an endogenous substance with elicitor activity, as well as the accumulation of isoflavone glucoside stress metabolites in the cells. The active compound was fractionated using phenylalanine ammonia lyase (PAL)-inducing activity in fresh cells as a marker. The elicitor active principle appears to be a low molecular weight (<2000 MW) water-soluble acidic oligosaccharide.     

巨型艾美耳球虫内生发育期超微结构的研究

鸡人工感染过巨型艾美耳球虫（Ｅｉｍｅｒｉａｍａｘｉｍａ）卵囊，巨型艾美耳球虫的裂殖生殖先由细胞核分裂，再在裂隙或缝隙处形成囊状突起，进而形成裂殖子，其过程伴随一系列细胞器的变化。小配子生成先由核伴随线粒体向周边移动，并向外隆起形成小配子的芽体，再进一步形成小配子。大配子形成过种中，胞浆内出现ＷＦＢ２和ＷＦＢ     

智能网联汽车内生安全问题与对策

智能网联汽车正成为新一代典型信息物理系统,面临着传统功能安全与现实网络安全甚至严峻信息安全等二重乃至三重交织问题复合叠加影响,导致这一现象的根本原因之一是智能网联汽车的内生安全问题—软件定义汽车趋势下的软硬件代码设计缺陷、漏洞/后门等问题。在分析智能网联汽车内生安全问题和现有网络安全防御局限性的基础上,提出了“不完全交集”原理和基于动态异构冗余架构的智能网联汽车内生安全理论和方法,通过将网络攻击带来的不确定性失效与软硬件随机性失效归一化为可用概率表达的广义鲁棒控制问题,使安全性指标达到可量化设计和可验证度量的程度,为一体化解决智能网联汽车网络安全和功能安全(信息安全)交织叠加难题提供了新路径,赋能智能网联汽车及车联网基础设施构建数字安全底座。     

天津人工海岸吹填土内源污染物分布规律探讨

为了查明人工海岸吹填土中内源污染物的分布规律和影响因素,对天津围海造陆形成的海陆水交换带吹填土的结构成分、渗透性以及总氮、总磷的分布进行了现场取样分析和室内模拟实验.结果表明:受地下水系统渗透性变化作用,内源污染物具有偏向性分布规律,向海侧高于背海侧;受吹填土自身颗粒结构变化以及离子交换、沉淀反应等理化作用,内源污染物表现为吹填久的区域高于新近吹填区.此研究对人工海岸地下水和海水的水质保护具有实际应用价值.     

基于研发型知识经济的内生增长模型

在罗默内生经济增长模型中引入人力资本因素,将技术进步和人力资本同时内生化,得出研发型知识经济增长的最优平衡路径。通过分析最优解以及各因素对经济增长的贡献,进一步说明了技术进步与人力资本在促进经济增长中的主导作用,并给出相应的政策建议。