首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   102篇
  免费   1篇
  2020年   1篇
  2018年   1篇
  2016年   1篇
  2015年   4篇
  2014年   4篇
  2013年   6篇
  2012年   8篇
  2011年   5篇
  2010年   5篇
  2009年   7篇
  2008年   6篇
  2007年   7篇
  2006年   1篇
  2005年   4篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   6篇
  2000年   2篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1992年   1篇
  1990年   1篇
  1989年   2篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1983年   2篇
  1982年   2篇
  1980年   2篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1970年   1篇
  1968年   1篇
  1937年   1篇
排序方式: 共有103条查询结果,搜索用时 15 毫秒
71.
RhoA organizes actin stress fibres and is necessary for cell transformation by oncogenes such as src and ras. Moreover, RhoA is implicated in cadherin clustering during the formation of adherens junctions. The catenin p120 has also been implicated in cadherin clustering through an unknown mechanism. Here we show that p120 selectively inhibits RhoA activity in vitro and in vivo. RhoA inhibition and the interaction of p120 with cadherins are mutually exclusive, suggesting a mechanism for regulating the recruitment and exchange of RhoA at nascent cell-cell contacts. By affecting RhoA activation, p120 could modulate cadherin functions, including suppression of invasion, neurite extension and junction formation.  相似文献   
72.
73.
74.
75.
76.
Contagious bovine pleuropneumonia (CBPP) is a cattle disease that has hampered the development of the livestock sector in sub-Saharan Africa. Currently, vaccination with a live vaccine strain is its recommended control measure although unofficial antimicrobial use is widely practiced. Here, modelling techniques are used to assess the potential impact of early elimination of infected cattle via accurate diagnosis on CBPP dynamics. A herd-level stochastic epidemiological model explicitly incorporating test sensitivity and specificity is developed. Interventions by annual vaccination, annual testing and elimination and a combination of both are implemented in a stepwise manner and their effectiveness compared by running 1000 simulations per intervention over ten years. The model predicts that among the simulated interventions, the ones likely to eliminate the disease from an isolated herd all involved annual vaccination of more than 75% of the animals with a vaccine that protects for at least 18 months combined with annual testing (and elimination of positive reactors) of 75% of the animals every six months after vaccination. The highest probability of disease elimination was 97.5% and this could occur within a median of 2.3 years. Generally, our model predicts that regular testing and elimination of positive reactors using improved tests will play a significant role in minimizing CBPP burden especially in the current situation where improved vaccines are yet to be developed.  相似文献   
77.
78.
The binomial test is applied for the problem of testing a hypothesis based on a sample of independent, but non-identically distributed random variables. The used basic idea is that each random variable indicates the presence of the hypothesis. Hence each random variable is transformed such that the binomial test can be used as a simple procedure.  相似文献   
79.
Peste des petits ruminants (PPR) is an important cause of mortality and production loss among sheep and goats in the developing world. Despite control efforts in a number of countries, it has continued to spread across Africa and Asia, placing an increasing burden on the livelihoods of livestock keepers and on veterinary resources in affected countries. Given the similarities between PPR and rinderpest, and the lessons learned from the successful global eradication of rinderpest, the eradication of PPR seems appealing, both eliminating an important disease and improving the livelihoods of the poor in developing countries. We conducted a benefit-cost analysis to examine the economic returns from a proposed programme for the global eradication of PPR. Based on our knowledge and experience, we developed the eradication strategy and estimated its costs. The benefits of the programme were determined from (i) the averted mortality costs, based on an analysis of the literature, (ii) the downstream impact of reduced mortality using a social accounting matrix, and (iii) the avoided control costs based on current levels of vaccination. The results of the benefit-cost analysis suggest strong economic returns from PPR eradication. Based on a 15-year programme with total discounted costs of US$2.26 billion, we estimate discounted benefits of US$76.5 billion, yielding a net benefit of US$74.2 billion. This suggests a benefit cost ratio of 33.8, and an internal rate of return (IRR) of 199%. As PPR mortality rates are highly variable in different populations, we conducted a sensitivity analysis based on lower and higher mortality scenarios. All the scenarios examined indicate that investment in PPR eradication would be highly beneficial economically. Furthermore, removing one of the major constraints to small ruminant production would be of considerable benefit to many of the most vulnerable communities in Africa and Asia.  相似文献   
80.
All hematological malignancies are characterized by considerable clinical heterogeneity. The diverse entities can be subdivided into a variety of prognosis-defining subtypes on the basis of cytogenetic aberrations and molecular mutations. To adapt the intensity of treatment to the patient’s individual risk profile, an exact classification of the subtypes on the basis of genetic markers is essential. Diverse fluorescent in situ hybridization (FISH) techniques thereby play a central role in interaction with classic chromosome banding analyses for clarifying findings of chromosome analyses, such as in the acute leukemias, or for classifying the diverse subtypes, as in the non-Hodgkin’s lymphomas. Depending on the disease, the clinical impact of FISH varies. It is used as the method of choice for genetic characterization (e.g., in multiple myeloma) or is used in combination with chromosome banding analysis. Furthermore, interphase FISH is essential when rapid confirmation of the diagnosis is needed, as in acute promyelocytic leukemia with the t(15;17)/PML-RARA rearrangement, for which therapy with all-trans retinoic acid (ATRA) should be immediately started.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号