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排序方式: 共有229条查询结果,搜索用时 31 毫秒
1.
探讨了非典对于中国电子商务的影响以及电子商务在此期间发挥出的作用、存在的不足,进而提出了关于如何促进中国电子商务进一步发展的思考和建议.  相似文献   
2.
牛心朴子草抗植物病毒组分的生物活性研究   总被引:18,自引:2,他引:16  
牛心朴子草地上部分醇浸粗提物(H)对烟草花叶病毒(TMV)有高抑制活性。该草抗植物病毒有效组分是菲并吲哚是西定生物总碱(G),半中枯斑法测定(G)制剂对TMV,马铃薯Y病毒(PVY),和芜菁花叶病毒(TUMV)呈现高活性;用酶联免疫法(Elisa)测定(G)制剂对TUMV的最佳浓度防效,与枯斑法测定结果基本要符。(G)中含量最丰的(1)7-脱甲氧基娃儿藤碱(antofine)是该草活性最高的主组分,它在10^-6g/ml浓度的TMV抑制率达60%。  相似文献   
3.
Summary. The cumulative number of human immunodeficiency virus (HIV) infections worldwide has reached 60 million in little over 30 years. HIV continues to spread despite a detailed understanding of the manner in which it spreads and measures which can prevent spread. Some governments have been highly successful in containing the spread of HIV through blood products and from mother to child and among injecting drug users. Lack of political will, lack of resources or challenges to widely accepted scientific evidence have held back similar interventions in other countries. It has proved much more difficult to reduce the sexual transmission of HIV in both high and low income countries. A wide range of strategies has been identified but it remains unclear which strategies deserve priority and what methods of promoting them have the greatest effect. There is ample evidence that awareness of HIV and changes in sexual behaviour have occurred widely but the penetration of information remains poor in some vulnerable groups especially adolescents and women in poorer countries. Further obstacles face those who have information about the risk. The subordinate position of women and a desire for large families are important obstacles to condom negotiation and use. Urbanization, poverty, conflict and declining public services all exacerbate unsafe sexual behaviour. We argue that so-called 'structural' interventions directed at these wider contexts of unsafe behaviour merit greater attention. Such approaches have the added benefit of being less susceptible to 'risk compensation' which has the potential to undermine strategies directed at reducing the transmission efficiency of HIV.  相似文献   
4.
Summary.  To help to design vaccines for acquired immune deficiency syndrome that protect broadly against many genetic variants of the human immunodeficiency virus, the mutation rates at 118 positions in HIV amino-acid sequences of subtype C versus those of subtype B were compared. The false discovery rate (FDR) multiple-comparisons procedure can be used to determine statistical significance. When the test statistics have discrete distributions, the FDR procedure can be made more powerful by a simple modification. The paper develops a modified FDR procedure for discrete data and applies it to the human immunodeficiency virus data. The new procedure detects 15 positions with significantly different mutation rates compared with 11 that are detected by the original FDR method. Simulations delineate conditions under which the modified FDR procedure confers large gains in power over the original technique. In general FDR adjustment methods can be improved for discrete data by incorporating the modification proposed.  相似文献   
5.
“非典”危机反应与危机心理干预   总被引:40,自引:0,他引:40  
面对突如其来的SARS流行,社会上普遍出现恐慌、焦虑、担忧等心理反应。如何帮助人们调整心态,应对危机,在危机中获得成长,已经成为心理学家当前最关心的课题。文章从心理学的角度出发,探讨了SARS危机下人们出现的身心反应以及危机可能引发的后果,提出了危机干预的方法、过程,初步构建了危机干预的模式。对于如何应对SARS引起的过度的危机反应,文章中也提出了自我心理调适的途径和方法。  相似文献   
6.
This study analyzes the image repair discourse by Chinese Health Minister Zhang Wenkang's discourse on SARS. The minister faced several accusations: the SARS outbreak was growing, the Chinese government had covered up the severity of this problem, the Chinese government ignored Taiwanese who suffered from SARS, and the Health Ministry provided information that was neither timely nor accurate. He employed several image repair strategies (denial, defeasibility, bolstering, minimization, differentiation, attack accuser, and corrective action). However, his messages were contradictory and apparently related on false information, so his efforts were unsuccessful and he was stripped of his office.  相似文献   
7.
本文阐述了计算机病毒的概念,对计算机病毒进行了分类,同时分析了各类病毒的特点。并着重介绍了对病毒的防范措施以及清除的方法。  相似文献   
8.
This article presents an overlooked case of research misconduct and violations of basic principles of medical and business ethics. When Bayer’s Cutter Laboratories realized that their blood products, Factor VIII and IX or antihemophiliac factor (AHF), were contaminated with human immunodeficiency virus (HIV), the financial investment in the product was considered too high to destroy the inventory. Cutter misrepresented the results of its own research and sold the contaminated AHF to overseas markets in Asia and Latin America without the precaution of heat treating the product recommended for eliminating the risk. As a consequence, hemophiliacs who infused the HIV-contaminated Factor VIII and IX tested positive for HIV and developed AIDS.  相似文献   
9.
本文指出了学生在微机教学实习中出现的若干问题,探讨了解决这些问题的方法。  相似文献   
10.
"非典"及其防治引发了对传统公私法调控机制的挑战,同时,更提出了相应法律调控机制创新的理论和实践要求.立足于"非典"防治具体制度措施及其对传统公、私法调控机制所带来的挑战和机遇,结合(西方)现代社会结构变迁的基本特点及其与新的法律调控机制间的互动关系,将"非典"防治及其相关制度建设,嵌入中国社会自1970年代末开启的市场化取向改革与民主法制化进程,进行了细致的分析.在充分理解和认识问题复杂性的基础上,对"非典"防治及其引发的对传统公私法调控机制的挑战,以及新兴社会法调控机制创新的可能对策选择及其基本方向进行思考.并最终论证了这样一个命题即中国社会的转型背景和"共时性"发展特征,决定了目前主流公、私法调控机制具有两面性和矛盾契合性;而且这一特性及其全面准确的把握,将深刻地影响和决定中国未来社会法调控机制的实际效果.  相似文献   
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