Isolation and purification of BVⅠ-2H from bee venom and analysis of its biological action

The medical use of bee venom for rheumatoid arthritis ( RA ) has a very long tradition. In this study, isolation and purification of polypeptides from bee venom were carried out on sephadex chromatography, heparin sepharose CL-6B chromatography and HPLC. Several fractions were extracted, and their effects on activation of splenocyte and THP-1 cell were studied. The inhibitory fraction was selected for further studies. Finally, BVⅠ-2H that the HPLC elution profiles was a single peak was isolated by C8 column. ESI- MS detection results showed that BVⅠ-2H was a fraction of bee venom, and the molecular weight of the major component was 644.8. BVⅠ-2H could inhibit ConA-induced splenocyte proliferation, IL-1 production and interfere with splenocyte cycle in mice. Moreover, BVⅠ-2H could inhibit PMA-induced TNFα production in THP-1 cells, which was due to its inhibitory effects on TNFα mRNA expression and protein phosphorylation of IκBα. Our studies indicated that BVⅠ-2H was one of the anti-inflammatory components of bee venom.     

L型连续退火炉退火工艺的模拟实验

结合唐钢镀锌线退火炉的工艺特点，热模拟了退火工艺，检验了退火后带钢的力学性能和金相组织，为实际生产提供了理论依据。     

Genetic and photoperiodic control of an avian reproductive cycle

European blackcaps,Sylvia atricapilla, with one breeding season per year, have a single-peaked annual testes cycle. However, African conspecifics from the Cape Verde Islands with two breeding seasons per annum demonstrate a two-peaked cycle. Both population-specific cycles reflect differences in the respective endogenous circannual rhythms. Experimental hybridization of birds of the two populations resulted in an intermediate pattern of testes cycle, thus demonstrating that there are genetic components for some temporal aspects in an avian reproductive cycle. Another characteristic of the African birds, their extremely rapid juvenile development and early sexual maturity (at an age of 5–6 months) proved largely to be a photoperiodic (short-day) effect in birds hatched in autumn. The same effect could also be induced in European conspecifics exposed to correspondingly short day-lengths.     

基于企业自身发展的核心能力管理

企业之间的竞争体现为核心能力的竞争，企业的多元化战略应围绕核心能力来进行。人们通过用户价值、独特性、延展性、难以模仿和替代性来识别企业的核心能力。对企业核心能力进行管理的基础在于核心能力具有生命周期。     

绿色设计及其应用分析

对绿色设计的国际背景、含义、特点、关键技术及典型方法进行了较全面的介绍 ,对绿色设计在我国的应用策略和步骤进行了分析 ,最后 ,对绿色设计在轻工机械设计中的应用进行了展望     

分数Hamilton圈与分数树形图

定义有向图的分数有向Hamilton圈和分数支撑树形图，讨论分数Hamilton圈、分数旅行售货员问题和分数支撑树形图基于线性规划的等价定义及多项式时间算法。     

图Cn∪Pm的算术标号

设Ｃｎ∪Ｐｍ（ｎ≥３，ｍ≥２，ｎ，ｍ∈Ｎ）表示一个圈Ｃｎ和一条与其不相交的路Ｐｍ组成的图，本文证明图Ｃｎ∪Ｐｍ是算术图。     

价格战的运用与应对研究

随着我国市场化改革的不断深入，价格战已经逐渐成为许多企业主动或被动频繁使用的策略。从产品生命周期，产品组合策略，产品边际成本等方面分析了运用价格战应考虑的因素，同时提出了应对价格战的措施和价格战向价值战转变的建议。     

Evolutionary and ecological implications of cardenolide sequestration in the monarch butterfly

Summary Monarch butterflies sequester cardenolides from their larval host plants in the milkweed genusAsclepias for use in defense against predation. Of 108Asclepias species in North America, monarchs are known to feed as larvae on 27. Research on 11 of these has shown that monarchs sequester cardenolides most effectively, to an asymptote of approximately 350 g/0.1 g dry butterfly, from plants with intermediate cardenolide contents rather than from those with very high or very low cardenolide contents. SinceAsclepias host plant species are distributed widely in space and time across the continent, monarchs exploit them by migration between breeding and overwintering areas. After overwintering in central Mexico, spring migrants east of the Rocky Mountains exploit three predominantAsclepias species in the southern USA that have moderately high cardenolide contents. Monarchs sequester cardenolides very effectively from these species. First generation butterflies are thus well protected against predators and continue the migration north. Across the northern USA and southern Canada most summer breeding occurs on a fourthAsclepias species and in autumn most of these monarchs migrate back to Mexican overwintering sites. The ecological implications of this cycle of cardenolide sequestration for the evolution of monarch migration are discussed.     

一类捕食者——食饵模型的定性分析

本文对一类捕食者——食饵模型进行定性分析,得到了非平凡平衡点全局稳定性的条件和正平衡点周围存在唯一极限环的充分条件,并且本文给出了1个关于这类系统“大范围”极限环的存在唯一性定理。