《氓》与《美狄亚》中女主人公对爱情悲剧的不同应对方式

《氓》和《美狄亚》中的女主人公，对于爱情全心全意地付出，得到的却是冷酷无情的背叛。面对背叛，她们勇敢地进行了抗争，以弱小的力量反抗强大的社会制度，给后人留下了震撼人心的悲壮之美。但是，由于中西方文化背景的差异，两位女主人公反抗的方式和力度有所差异。     

Structure and conserved RNA binding of the PAZ domain

The discovery of RNA-mediated gene-silencing pathways, including RNA interference, highlights a fundamental role of short RNAs in eukaryotic gene regulation and antiviral defence. Members of the Dicer and Argonaute protein families are essential components of these RNA-silencing pathways. Notably, these two families possess an evolutionarily conserved PAZ (Piwi/Argonaute/Zwille) domain whose biochemical function is unknown. Here we report the nuclear magnetic resonance solution structure of the PAZ domain from Drosophila melanogaster Argonaute 1 (Ago1). The structure consists of a left-handed, six-stranded beta-barrel capped at one end by two alpha-helices and wrapped on one side by a distinctive appendage, which comprises a long beta-hairpin and a short alpha-helix. Using structural and biochemical analyses, we demonstrate that the PAZ domain binds a 5-nucleotide RNA with 1:1 stoichiometry. We map the RNA-binding surface to the open face of the beta-barrel, which contains amino acids conserved within the PAZ domain family, and we define the 5'-to-3' orientation of single-stranded RNA bound within that site. Furthermore, we show that PAZ domains from different human Argonaute proteins also bind RNA, establishing a conserved function for this domain.     

硕士文凭不等于求职力

就业压力之大,使很多本科生在求职前未战先怯,读研成为可选的缓冲途径和回避就业问题的方式.既然原始动机不是献身科学、探寻真理,便能肯定大部分此类读研者以后不会从事纯粹的科研工作,3年后就业问题依旧会卷土重来.     

旅游业主流发展战略模式比较与模式选择探讨

在回顾相关研究基础上 ,通过对两种主流模式的比较分析 ,并结合我国旅游行政管理与旅游产业市场化实践 ,认为两者之间并不完全对立 ,实践中存在能够对接的可能 .充分发挥各自的长处 ,求真务实地实现政府行为与市场的有效对接是科学选择旅游业发展战略模式的关键     

光本性否定光速不变原理及现行米定义

1961年、1967年、2005年、2006年国外公布了几个实验报告,直接和间接地示意:光子带有微量负电荷。加之牛顿在1704年和爱因斯坦在1905年都曾经明示过:光束可能是经典性质点流。于是,光子就应该是带着微量负电荷的经典性质点。随之,光的折射、反射、衍射、干渉及偏振等各种光学实验现象,都是光子与其近旁的介质原子核及其核外电子之间的库仑力作用,所产生的光子速度方向发生了改变后才形成的可视影像。光本性中的这种经典性质点特征,逻辑地否定了光速不变原理及现行米定义。     

《合锦回文传》作者并非李渔

本人反复对照李渔的作品和《合锦回文传》，参阅前人的研究成果并研究了大量明、清之际的才子佳人小说，从而得出结论．《合锦回文传》不是李渔所作。     

The genetic defect in familial Alzheimer's disease is not tightly linked to the amyloid beta-protein gene

Amyloid beta-protein (AP) is a peptide of relative molecular mass (Mr) 42,000 found in the senile plaques, cerebrovascular amyloid deposits, and neurofibrillary tangles of patients with Alzheimer's disease and Down's syndrome (trisomy 21). Recent molecular genetic evidence has indicated that AP is encoded as part of a larger protein by a gene on chromosome 21 (refs 5-7). The defect in the inherited autosomal dominant form of Alzheimer's disease, familial Alzheimer's disease (FAD), has been mapped to the same approximate region of chromosome 21 by genetic linkage to anonymous DNA markers, raising the possibility that this gene product, which could be important in the pathogenesis of Alzheimer's disease, is also the site of the inherited defect in FAD (ref. 5). We have determined the pattern of segregation of the AP gene in FAD pedigrees using restriction fragment length polymorphisms. The detection of several recombination events with FAD suggests that the AP gene is not the site of the inherited defect underlying this disorder.     

刺猬、黄鼠和大白鼠对阶梯式低压缺氧耐受性的比较

本实验以体温、心率和呼吸频率为指标观察刺猬、黄鼠和大白鼠三种动物在常温(20±2℃)中清醒状态下对阶梯式低压缺氧的反应。各组动物均为6例。在低压舱中模拟高空低压缺氧、在模拟高度4000米、5000米及6000米阶段各停留30分钟,7000米停留2小时。结果表明:对缺氧的耐受性以刺猬最强,黄鼠次之,大白鼠最差。此结果提示:冬眠动物可能比非冬眠动物对缺氧具更强的耐受性。     

Movement of 'gating charge' is coupled to ligand binding in a G-protein-coupled receptor

Activation by agonist binding of G-protein-coupled receptors (GPCRs) controls most signal transduction processes. Although these receptors span the cell membrane, they are not considered to be voltage sensitive. Recently it was shown that both the activity of GPCRs and their affinity towards agonists are regulated by membrane potential. However, it remains unclear whether GPCRs intrinsically respond to changes in membrane potential. Here we show that two prototypical GPCRs, the m2 and m1 muscarinic receptors (m2R and m1R), display charge-movement-associated currents analogous to 'gating currents' of voltage-gated channels. The gating charge-voltage relationship of m2R correlates well with the voltage dependence of the affinity of the receptor for acetylcholine. The loop that couples m2R and m1R to their G protein has a crucial function in coupling voltage sensing to agonist-binding affinity. Our data strongly indicate that GPCRs serve as sensors for both transmembrane potential and external chemical signals.     

析动词的时与表示时间的不一致现象

随着语言的发展,动词的时与表示时间的不一致现象越来越多,本文从语意、语用方面分析了其原因,归纳了动词与表示时间不一致的七种情况,以便在实际运用中灵活地使用动词的时态.     

A signal sequence is not sufficient to lead beta-galactosidase out of the cytoplasm

Escherichia coli strains have been constructed in which lacZ, the gene for the cytoplasmic enzyme beta-galactosidase, is fused to lamB, the gene for an outer membrane protein. One such strain produces a beta-galactosidase which remains cytoplasmic even though it possesses the complete signal sequence of the lamB protein precursor at the amino-terminal end.     

翻译是一种模式——本雅明《译者的任务》的几点解读

在《译者的任务》一文中，本雅明从翻译是一种模式，旨在揭示不同语言之间潜在的亲缘关系出发，提出了“纯语言”的概念，并以这一抽象的概念为核心，把传统翻译研究中译作与原作的二元对立关系和谐地统一到对“纯语言”的终极追寻中，颠覆了传统意义上翻译的忠实与自由。他所提出的译者的任务，就是探索“纯语言”，在自己的语言中将“纯语言”从另一种语言的魔咒中释放出来，让“纯语言”之先通过翻译这座桥梁更充分地照耀原作。本雅明对翻译理论的独特思考，拓宽了翻译研究的视野。文中试图通过文本细读的方式，结合笔者的理解．对本雅明所提出的观点进行几点解读。     

析动词的时与表示时间的不一致现象

随着语言的发展 ,动词的时与表示时间的不一致现象越来越多 ,本文从语意、语用方面分析了其原因 ,归纳了动词与表示时间不一致的七种情况 ,以便在实际运用中灵活地使用动词的时态。     

加宽桥梁不同拼接模式下的抗震性能比较分析

介绍了目前高速公路桥梁加宽常用的几种拼接模式及其优缺点,结合工程实例,借助MIDAS有限元分析软件建立空间有限元模型,分析采用不同拼接模式加宽后成桥状态的抗震性能.从抗震分析的角度,对几种拼接模式进行比较分析.结果表明,采用双柱加宽的桥梁,“上下部均连接”与“上连下不连”两种拼接模式下的成桥状态抗震性能差别不大;采用独柱加宽的桥梁,从成桥抗震性能分析,“上下部均连接”的拼接模式要优于采用“上连下不连”拼接模式.     

Carboxy terminus of vasopressin required for activity but not binding

Vasopressin antagonists are valuable pharmacological tools for investigating physiological and behavioural functions of the nonapeptide arginine-vasopressin (AVP). The removal of glycinamide from the carboxy terminus of AVP drastically reduces its characteristic vasopressor and antidiuretic activities. In contrast to this we show here that removal of the carboxy-terminal glycinamide or the glycine at position 9 from several vasopressin antagonists makes little difference to their ability to block vasopressor and antidiuretic responses to AVP. These data demonstrate the critical structural requirements of the carboxy-terminal position for receptor activation, in contrast to the lack of such requirements for receptor binding. They also provide an avenue to a wide variety of antagonists substituted at the carboxy terminus (for example radiolabelled derivatives and affinity ligands) and suggest clues for the development of more potent and/or selective antagonists.