橡胶树胶乳全蛋白的提取及双向电泳分析

以橡胶树无性系RRIM600为材料，采用TCA(三氯乙酸)-丙酮沉淀法提取胶乳全蛋白，17 cm pH 5～8固相pH梯度预制干胶条和快速银染法对提取的蛋白进行分离和染色，所得到的电泳图谱背景清晰，横条纹和竖条纹少，且蛋白点数量多。通过本研究获得了高分辨率的胶乳全蛋白双向电泳(2-DE)图谱的方法，为进一步开展橡胶树胶乳全蛋白质组学研究奠定了基础。     

Changes in endothelin-1 and atrial natriuretic factor and the effect of atrial natriuretic factor on the change of endothelin-1 in asthmatic guinea pigs

AIM: To investigate the possible role of endothelin(ET-1) in asthma pathogenesis and the effect of atrial natriuretic factor (ANF) on changes of ET-1. METHODS: Measuring the contents of endothelin-1(ET-1),atrial natriuretic factor(ANF),cGMP in plasma and bronchoalveolar lavage fluid (BALF) of guinea pigs. RESULTS: The contents of ET-1, ANF and cGMP in asthma group were higher than that of the control group; There was a significant negative correlation between ET-1 and ANF( r=-0.638,P <0.05) in plasma of the asthma group, and a significantly negative correlation between ET-1 and ANF( r=-0.921,P <0.01) in BALF of the asthma group. There was a significantly positive correlation between ANF and cGMP( r=0.848,P <0.01) in plasma of the asthma group,and a significantly positive correlation between ANF and cGMP ( r=0.831,P <0.01) in BALF of the asthma group. The levels ET-1 in the asthma+rat ANF(rANF) group were lower than those in the asthma group,and the levels of cGMP in the asthma+rat ANF(rANF) group were higher than those in the asthma group after ceasing to infuse rANF for guinea pigs for 30 minutes.CONCLUSION: ET-1 might play an important role in the pathogenesis of asthma.ANF might inhibit production of ET-1.     

Detection of Serotypes and Virulence Factors of Escherichia coli from Piglets in Beijing

To investigate the cause of piglets diarrhea, and the distribution of the serotype and virulence factors of swine Escherichia coli in Beijing, 400 diarrhea samples were collected. TSA serum agar culture method was used to isolate Escherichia coli, serotype identification test and virulence factor genes test were used to verify the presence of O-antigen. 64 strains of E.coli were isolated from 400 diarrhea samples, among which 42 strains of E.coli were classified as 8 serotypes:O101(18.7%),O64(12.5%),O8(10.9%),O20(10.9%),O45(4.7%),O149(4.7%),O2(1.6%) and O89(1.6%), and the major virulence factors were STa, Stx2e, astA and eaeA. There were 8 mainly serotypes that caused piglets diarrhea in Beijing area, among which O101 serotype accounted for the highest proportion. The major virulence factors were astA and eaeA, accounted for more than 50% of all strains, STa and Stx2e accounted for more than 30% of all strains. These data would provide effective data to support the prevention and control of piglet diarrhea in Beijing.     

山西省朔州市红旗新区规划环评循环经济分析

山西省朔州经济开发区红旗新区,以新型工业、现代农业和生态旅游三类产业为支撑,与传统工业园区相比存在明显特色,且所在区域资源丰富、交通便利、政策利好、产业深厚.该文对朔州市红旗新区总体规划环境影响评价中的循环经济进行重点分析,并提出了几点思考.     

扶绥县蔗区耕地地力调查与发展对策

通过对广西扶绥县甘蔗种植的分布、生产情况以及当地耕作条件、耕地地力等情况进行调查,指出扶绥县甘蔗生产存在的主要问题,提出培肥耕地地力、加强灌溉设施建设、选用优良品种、推广机械化深耕深松技术、实行稻蔗轮作、推广甘蔗测土配方施肥技术、加强肥料市场监管力度等促进扶绥县甘蔗生产发展的对策。     

螺旋插补铣在加工多孔盘类零件中的应用

传统的盘类加工工艺方法在加工此类Q345材质零件时，刀具成本较高，生产效率低。通过生产实例的加工工艺，证明了螺旋插补铣在孔加工中的低刀具成本优势与高的生产效率。     

奶牛集约化生产体系中铜素产污系数的测定

通过对集约化奶牛场的育成牛和泌乳牛各季节的粪尿产生量进行测定,并且分析粪样和尿样,从而计算出育成牛和泌乳牛的铜产污系数,并比较两者各季节间的差异性。结果显示集约化奶牛场的育成牛铜产污系数4个季节平均为0.14g/(head.d),泌乳牛铜产污系数4个季节平均为0.31g/(head.d),泌乳牛铜产污系数远大于育成牛铜产污系数。     

基层环境监测站能力现状及发展思路——以新疆博州环境监测体系为例

以新疆博州环境监测体系为例,分析了地级市站及县级站作为基层环境监测站的能力现状、所面临的机遇和挑战,试图寻找一条破解现实与发展、机遇与问题并存的发展之路。     

高校图书馆新管理模式影响因子初探

通过对图书馆新管理模式影响因子的研究,分清这些影响因子有哪些,并揭示它们和新管理模式之间的内在联系,对现实工作具有积极的指导意义。     

热-应力耦合场作用下含缺陷压力管道的应力强度因子研究

含有轴向长裂纹承受超高压的厚壁压力管道,当其内外壁温度不一致时会产生热应力,从而使总的应力场发生变化,裂纹尖端的应力强度因子也将发生变化。本文用有限单元法计算了由稳态热荷载和内压力共同引起的应力强度因子,并通过选取几组不同的厚壁管道几何参数、裂纹参数和温度参数,分析了它们对应力强度因子的影响规律。总结后发现,热-应力耦合场作用下,应力强度因子随径比、裂纹深度比和温度比的增加而增加,且外壁温度高于内壁时得到的应力强度因子更大,压力管道处于更加危险的工况,工程上需要特别注意。