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   1126篇
  免费   126篇
  2021年   11篇
  2018年   11篇
  2016年   14篇
  2015年   30篇
  2014年   39篇
  2013年   49篇
  2012年   69篇
  2011年   99篇
  2010年   34篇
  2009年   41篇
  2008年   43篇
  2007年   42篇
  2006年   38篇
  2005年   35篇
  2004年   45篇
  2003年   25篇
  2002年   25篇
  2001年   32篇
  2000年   29篇
  1999年   22篇
  1998年   7篇
  1997年   11篇
  1996年   9篇
  1995年   11篇
  1994年   7篇
  1993年   9篇
  1992年   30篇
  1991年   15篇
  1990年   20篇
  1989年   20篇
  1988年   20篇
  1987年   18篇
  1986年   23篇
  1985年   28篇
  1984年   14篇
  1983年   19篇
  1982年   18篇
  1981年   8篇
  1980年   20篇
  1979年   28篇
  1978年   12篇
  1977年   13篇
  1974年   14篇
  1973年   17篇
  1972年   12篇
  1971年   10篇
  1970年   10篇
  1969年   10篇
  1968年   10篇
  1967年   6篇
排序方式: 共有1252条查询结果,搜索用时 31 毫秒
51.
52.
In this case report, a 25-year-old female with chronic dysphagia spastica(difficulty swallowing because of constriction of the throat muscles) was treated with 20 sessions of frontal electromyographic(EMG) biofeedback and home-relaxation practice. The subject monitored on a 10-point scale her difficulty swallowing during meals for 2 months prior to treatment, during treatment, and after treatment. There was a significant decrease in reported difficulty swallowing associated with frontalis EMG feedback. Improvement was maintained at a 6-month follow-up.  相似文献   
53.
Summary Mutant strains of Saccharomyces cerevisiae auxotrophic for deoxythymidine monophosphate (dTMP) were isolated and characterized. Two distinct classes of auxotrophs were obtained. One class had a simple requirement for dTMP and was analogous to thymine-requiring bacteria. The second class required dTMP, adenine, histidine and methionine and this complex nutritional phenotype was due to defects in folate metabolism. The dTMP-dependent growth of respiratory-competent grande auxotrophs was found to be markedly affected by media composition and carbon source. In the absence of dTMP thymineless death occurred in both mutant classes.  相似文献   
54.
55.
56.
BackgroundAdvances in antimalarial drug development are important for combating malaria. Among the currently identified antimalarial drugs, it is suggested that some interact directly with the malarial parasites while others interact indirectly with the parasites. While this approach leads to parasite elimination, little is known about how these antimalarial drugs impact immune cells that are also critical in malarial response.MethodsHerein, the effects of two common antimalarial drugs, chloroquine and quinine, on platelets were explored at both the bulk level, using high performance liquid chromatography, and the single cell level, using carbon-fiber microelectrode amperometry, to characterize any changes in chemical messenger secretion.ResultsThe data reveal that both drugs cause platelet activation and reduce the number of platelet exocytosis events as well as delay fusion pore opening and closing.ConclusionsThis work demonstrates how chloroquine and quinine quantitatively and qualitatively impact in vitro platelet function.General significanceOverall, the goal of this work is to promote understanding about how antimalarial drugs impact platelets as this may affect antimalarial drug development as well as therapeutic approaches to treat malarial infection.  相似文献   
57.
58.
In an era of rapid global change, our ability to understand and predict Earth's natural systems is lagging behind our ability to monitor and measure changes in the biosphere. Bottlenecks to informing models with observations have reduced our capacity to fully exploit the growing volume and variety of available data. Here, we take a critical look at the information infrastructure that connects ecosystem modeling and measurement efforts, and propose a roadmap to community cyberinfrastructure development that can reduce the divisions between empirical research and modeling and accelerate the pace of discovery. A new era of data‐model integration requires investment in accessible, scalable, and transparent tools that integrate the expertise of the whole community, including both modelers and empiricists. This roadmap focuses on five key opportunities for community tools: the underlying foundations of community cyberinfrastructure; data ingest; calibration of models to data; model‐data benchmarking; and data assimilation and ecological forecasting. This community‐driven approach is a key to meeting the pressing needs of science and society in the 21st century.  相似文献   
59.
60.
Respiratory syncytial virus (RSV) is a high priority target for vaccine development. One concern in RSV vaccine development is that a non-live virus vaccine would predispose for enhanced disease similar to that seen with the formalin inactivated RSV (FI-RSV) vaccine. Since a mAb specific to RSV G protein can reduce pulmonary inflammation and eosinophilia seen after RSV infection of FI-RSV vaccinated mice, we hypothesized that RSV G peptides that induce antibodies with similar reactivity may limit enhanced disease after subunit or other non-live RSV vaccines. In support of this hypothesis, we show that FI-RSV vaccinated mice administered RSV G peptide vaccines had a significant reduction in enhanced disease after RSV challenge. These data support the importance of RSV G during infection to RSV disease pathogenesis and suggest that use of appropriately designed G peptide vaccines to reduce the risk of enhanced disease with non-live RSV vaccines merits further study.  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