H9N2亚型禽流感病毒聚合酶基因的克隆及序列分析

采用RT-PCR方法对1株H9N2亚型禽流感病毒Ck/GS/2/99株RNA聚合酶基因PB2、PB1和PA分别进行了扩增,将其克隆到pGEM-T easy载体后进行序列测定与分析。结果表明,该株病毒的PB2、PB1和PA基因开放阅读框(ORF)分别由2280、2274和2 151个碱基组成,分别编码759、757和716个氨基酸。经同源性与系统发生树分析,该毒株RNA聚合酶基因PB2、PB1和PA与Ck/NX/4/99株的核苷酸和氨基酸同源性均在98%以上,另外这3个基因与Dk/HK/Y280/97、Sw/HK/9/98和Qu/HK/NT/28/99株的关系密切。     

H2O2诱导PC12细胞凋亡前后miRNA的变化及探讨

目的用微小RNA(miRNA)基因芯片技术检测H2O2诱导凋亡的PC12细胞和正常PC12细胞miR-NA的表达谱差异。方法分别以不同浓度的H2O2处理PC12细胞12h,用MTT和流式细胞仪检测处理后细胞的生长活力和凋亡情况;分别提取A(0浓度H2O2处理组)和B(400nmol/LH2O2处理组)PC12细胞的miRNA做miRNA基因芯片检测。结果以A组作为对照,30、50、100、200、400nmol/L的H2O2处理的PC12细胞生存率分别为(92±9.80)%、(90±14.70)%、(80±13.85)%、(54±12.33)%、(22±7.35)%(P<0.01);0、30、50、100、200和400nmol/L的H2O2处理的PC12细胞早期凋亡率分别为2.6%、5.2%、7.2%、10.4%、16.6%、72.2%;在样品A中共筛选出68个有效表达的miRNA分子数据,在样品B中筛选出46个有效表达的miRNA分子数据,两者样品中均检测到有效表达的miRNA分子有39个,其中与样品A相比,在样品B中显著性下调表达的有6个。结论为脑缺血再灌注损伤中神经细胞凋亡的机制和治疗的研究提供了理论依据和新的研究思路。     

Nixon and the Jews

ABSTRACT

In public the 37th President of the United States did not express hostility or disparagement, or show any signs of religious prejudice towards Jews. But inside the White House, Richard M. Nixon's remarks were often scurrilous. His antisemitism was not casual; it was close to compulsive. And it could be coupled with other seething grievances, for example, towards liberals, radicals, the media, Blacks and Italian-Americans. Yet Nixon controlled his antisemitism. It had no adverse effect on Jewish life, either at home or abroad. The malice that he nurtured remained unmobilized. Apart from a few limited personnel instances (mostly but not completely ignored by Nixon's underlings), it is impossible to connect private resentment to public policy, probably because the barriers to the expression of antisemitism in the United States have been so high. The ugliness of his utterances in the Oval Office revealed his character, but did not extend outward to shape the processes of governance. A disconnect can therefore be discerned between what he felt and how he acted. Most American Jews voted for Nixon's Democratic opponents in 1968 and 1972. But even Jews who voted against him, even those who loathed him, have often acknowledged that Nixon's policies fortified the security of Israel; and he was proud of his support for the Jewish state during the Yom Kippur War. What betrayed Nixon, and what forced him to resign the presidency, was his decision to instal a secret taping system in the Oval Office. When the tapes were played in 1974, he showed himself to be conspiring to obstruct justice. In subsequent years, further exposure of the tapes revealed the extent and intensity of Nixon's antipathy to Jews. The expletives that had to be deleted did much to besmirch the dignity of the office. But such was the stigma the political culture attached to antisemitism that, had his bigotry become public before 1968, Nixon's career would have been over.     

H9亚型禽流感病毒RT-PCR检测方法的建立

通过分析流感数据库中123个HA序列,根据HA保守区序列设计并合成了1对引物,建立了一步法RT-PCR检测方法,预期扩增片段大小为732 bp。通过对H9亚型禽流感病毒(AIV)不同稀释度的尿囊液和棉拭子浸出液进行检测,证实病毒尿囊液的最低检出量为1×104.7EID50/mL;阳性棉拭子的最低检出量为1×102.5EID50/mL。用该方法检测H1~H15亚型AIV和鸡新城疫病毒等其他14种禽病病原,结果仅有H9亚型AIV出现特异性目的条带,而其他均未出现目的条带。脏器及咽喉、泄殖腔棉拭子样品在1∶10稀释度下,病毒分离和RT-PCR方法可以达到相同的阳性检出率。表明建立的AIV H9亚型RT-PCR方法具有较好的特异性和敏感性。     

三株鸭源H9N2亚型禽流感病毒福建株全基因的测序及遗传进化分析

为明确3株鸭源H9N2亚型禽流感病毒福建株A/Muscovy duck/Fujian/CL/1997(H9N2)(简称CL株)、A/duck/Fujian/MH/2003(H9N2)(简称MH株)和A/duck/Fujian/FQ2/2007(H9N2)(简称FQ2株)全基因组的分子特征和遗传进化情况,采用RT-PCR方法扩增这3株病毒全基因片段,并进行序列比较及遗传进化分析。结果表明,所克隆的8个基因片段均有完整的开放阅读框,其血凝素基因蛋白裂解位点的氨基酸组成为-RSSR*GLF-,为不连续的碱性氨基酸,其静脉接种指数远小于1.2,均符合低致病性AIVHA蛋白裂解位点特征;CL株和MH株的HA基因在遗传进化上属于常见的CK/BJ/1/94群系;FQ2株HA基因在遗传进化上属于DK/HK/Y280/97群系,3株H9N2亚型AIV HA基因在遗传进化上均属于经典的欧亚种系。3株H9N2亚型AIV NA基因颈部均存在缺失,CL株和MH株的NA基因在遗传进化上属于常见的CK/BJ/1/94群系,FQ2株NA基因在遗传进化上属于G1群系。CL株和MH株的其他6个基因在遗传进化上均和经典的CK/BJ/1/94一致,而FQ2株则可能是由不同流感病毒基因亚系间发生自然重排的产物。     

Russia,the death penalty,and Europe: the ambiguities of influence

Studies of capital punishment worldwide investigate how international influence affects the death penalty. We analyze European influence on the death penalty in Russia over the imperial, Soviet, and post-Soviet periods, using two parameters: the changing mechanisms of influence in each period and the death penalty's significance in the broader spectrum of punitive violence. On the first parameter, in the tsarist period, European influence on Russian policy was “productive” – exercised through prestige, moral suasion, and “diffusion.” In the Soviet period, European influence was blocked. In the post-Soviet period, European influence is coercive, as the Council of Europe has unsuccessfully sought to compel Russia to abolish its death penalty. On the second parameter, the death penalty in Russia has always been only one of many forms of state-sanctioned punitive killing. In consequence, the Council's involvement in Russia's death penalty has produced an incoherent policy outcome and has entangled the Council in Russia's authoritarian politics. Russia thus exemplifies the hazards of external involvement in death penalty abolition.     

H. G. Wells's The Time Machine and the “Odd Consequence” of Progress

The Time Machine of H. G. Wells stands as one of the foundational works of science fiction. It is a true product of its time, a reflection of the fast pace of technological development and social change that makes a romance of the ideology of advancement for its own sake. But between the lines of its “adventure” plot, we find evidence of another, more complex story being told. Wells's work is plagued by ambivalence about the outcome of social and scientific progress—the selfsame progress that gave birth to the time machine in the first place. The Time Machine, in short, is preoccupied by an anxiety about a catastrophe just around the corner, not one born of global war or political turmoil but rather of the absence of turmoil, of need, of struggle. The idea and possibility of fiction itself becomes entangled in this problem of the everyday catastrophe, as it nearly suffocates under the conditions of the utopian society which it creates.     

Foreign aid: An instrument for fighting communism?

In this paper, we test the argument that the sizeable reduction in aggregate aid levels in the 1990s was due to the end of the Cold War. We test two different models using a dynamic econometric specification on a panel of 17 donor countries, spanning the years 1970–97. We find aid to be positively related to military expenditures in the former Eastern Bloc during the Cold War, but not in the 1990s, suggesting that the reductions in aid disbursements are driven by the disappearance of an important motive for aid. We also study the effect on aid allocation, but here we do not find any robust effects of the end of the Cold War.