The 2009 pandemic (H1N1) viruses isolated from pigs show enhanced pathogenicity in mice

Since the emergence of the 2009 pandemic (H1N1) virus (2009/H1N1) in April 2009, cases of transmission from humans to pigs have been reported frequently. In our previous studies, four 2009/H1N1 variants were isolated from pigs. To better understand the phenotypic differences of the pig isolates compared with the human isolate, in this study mice were inoculated intranasally with different 2009/H1N1 viruses, and monitored for morbidity, mortality, and viral replication, cytokine production and pathological changes in the lungs. The results show that all isolates show effective replication in lungs, but varying in their ability to cause morbidity. In particular, the strains of A/swine/Nanchang/3/2010 (H1N1) and A/swine/Nanchang/F9/2010 (H1N1) show the greatest virulence with a persisting replication in lungs and high lethality for mice, compared with the human isolate A/Liaoning /14/2009 (H1N1), which shows low virulence in mice. Furthermore, the lethal strains could induce more severe lung pathological changes and higher production of cytokines than that of other strains at an early stage. Amino acid sequence analysis illustrates prominent differences in viral surface glycoproteins and polymerase subunits between pig isolates and human strains that might correlate with their phenotypic differences. These studies demonstrate that the 2009/H1N1 pig isolates exhibit heterogeneous infectivity and pathogencity in mice, and some strains possess an enhanced pathogenicity compared with the human isolate.     

德菲尔法构建重大动物疫病预警指标体系

[目的 ]构建重大动物疫病暴发流行预警指标体系。[方法 ]以禽流感和口蹄疫为例,采用文献调研法和德菲尔专家咨询法中的专家会议法初拟重大动物疫病预警体系的框架和指标;应用德菲尔专家咨询法评价预警指标的重要性、可操作性;应用组合权重法比较各指标综合影响的大小,并将指标分类。[结果 ]筛选出禽流感和口蹄疫预警预报一级指标6项(易感动物、饲养管理和免疫情况等)以及二级指标14项(免疫效果、环境消毒、温度等),并将指标分为三类(关键指标、重要指标和一般指标)。[结论 ]初步构建了重大动物疫病暴发流行预警指标体系。     

塔落岩黄芪、细枝岩黄芪及其变异型的生理特性研究

本文研究了毛乌素沙漠地区塔落岩黄芪和细枝岩黄芪及其变异型的生理学特性。结果表明,塔落岩黄芪和细枝岩黄芪各与其变异型之间在生理特性方面存在着极其显著的差异。     

杂交狼尾草亲本的开花特性

杂交父本象草Ｎ５１是对光照最为敏感的短日照作物,每日９ｈ,光照处理２～３周,能有效地诱导抽穗开花。象草的穗由分蘖穗和分枝穗组成,由于单株分蘖穗和分枝穗发育程度的差异和群体中个体间的差异致使Ｎ５１群体散粉期可达３０ｄ,散粉高峰期２周。母本Ｔｉｆｔ２３Ａ在南京能完成生育过程,开花期与播期有关,相关系数为０．８８６,群体散粉期与Ｎ５１同样有３０ｄ。由于亲本花期长,因此花期能很好地相遇、杂交、结实     

热敏电阻冰点仪法测定生鲜牛乳中冰点的研究

利用热敏电阻冰点仪法测定生鲜牛乳中的冰点,对该方法的重复性、灵敏度以及掺水掺盐对生鲜牛乳冰点值的影响等方面进行了研究.此方法的检测极限值为2.4 m℃.     

不同激素剂量对幼鼠超数排卵及超排卵质量的影响

应用国产激素制剂对３～８周龄昆明种小白鼠进行了超数排卵处理,重点观察了不同激素剂量对幼龄小鼠的超排效果及超排卵质量的影响。实验结果表明,以ＰＭＳＧ与ｈＣＧ各１０ＩＵ剂量超排３～８周龄小鼠,５周龄小鼠的超排效果（平均获卵８３．８±１０．２个）极显著（Ｐ＜０．０１）好于４～８周龄小鼠的超排效果（平均获卵３９．２～４９．８个）,而３周龄小鼠超排卵受精后体外培养的卵裂率（９７．１％）、桑椹胚率（８６．８％）和囊胚率（６５．１％）与４～８周龄超排卵的（分别为８５．５％～１００．０％、９４．９％～１００．０％和６３．２％～８７．７％）相近;以ＰＭＳＧ与ｈＣＧ各５ＩＵ剂量超排３～５周龄小鼠,３周龄小鼠的超排效果（平均获卵５９．０±６．５个）显著（Ｐ＜０．０５）好于４周龄小鼠的超排效果（平均获卵３１．４±４．９个）,并极显著（Ｐ＜０．０１）好于５周龄小鼠的超排效果（平均获卵２１．４±３．３个）;以ＰＭＳＧ与ｈＣＧ各１５ＩＵ剂量超排３～５周龄小鼠,３周龄小鼠的超排效果（平均获卵４８．６±７．３个）显著（Ｐ＜０．０５）好于５周龄小鼠的超排效果（平均获卵２５．２±５．８个）,也好于４周龄小鼠的超排效果（平均获卵４０．２±５．１个     

刑侦犬锁定"苦行僧"毒贩--云南腾冲"3·12"特大跨国贩毒案侦破纪实

这是一起在云南警方组织开展的“天网三号”禁毒专项行动中多警种协作、群众踊跃参与、警犬投入侦破的典型案例:2006年3月12日,当3名嫌疑人面对从两公里外查获的3背包沉甸甸的毒品海洛因及其他赃物拒不认罪、案件侦查陷入僵局时,刑侦犬“安普贵”奉命出击,把毒品和毒贩锁定在一     

巴比妥类镇静剂的检测研究进展

本文对巴比妥类安眠镇静剂检测方法的研究进展进行了综述。重点讨论了样品前处理方法及各种衍生化方法,GC、GC-MS、HPLC、HPLC-MS等检测方法。     

添加甲酸对白花草木樨青贮品质的影响

在收获后经过0、8和30h晾晒的初花期草木樨(干物质含量分别为27.36%、38.69%和44.98%)原料中,加入甲酸(添加量为2.5、4.0和5.5ml/kg)进行青贮。结果表明,添加甲酸能使草木樨青贮料氨态氮含量降低,并保存较多的可溶性糖;添加甲酸4.0ml/kg对三个干物质水平草木樨青贮均有良好效果,但以干物质含量27.36%组效果最好。