首页 | 官方网站   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   2990738篇
  免费   262963篇
  国内免费   13204篇
医药卫生   3266905篇
  2021年   53045篇
  2020年   34986篇
  2019年   57867篇
  2018年   70307篇
  2017年   53193篇
  2016年   58570篇
  2015年   73093篇
  2014年   107192篇
  2013年   172159篇
  2012年   80390篇
  2011年   78682篇
  2010年   113694篇
  2009年   118698篇
  2008年   65945篇
  2007年   67549篇
  2006年   78851篇
  2005年   74081篇
  2004年   76413篇
  2003年   67439篇
  2002年   57547篇
  2001年   85181篇
  2000年   77124篇
  1999年   80588篇
  1998年   63061篇
  1997年   60961篇
  1996年   53087篇
  1995年   53953篇
  1994年   48247篇
  1993年   45015篇
  1992年   53959篇
  1991年   52090篇
  1990年   49095篇
  1989年   49240篇
  1988年   45436篇
  1987年   44270篇
  1986年   42076篇
  1985年   42639篇
  1984年   40771篇
  1983年   37763篇
  1982年   38473篇
  1981年   36534篇
  1980年   34499篇
  1979年   32511篇
  1978年   30460篇
  1977年   28187篇
  1976年   25910篇
  1975年   24584篇
  1974年   24419篇
  1973年   23334篇
  1972年   21909篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
Journal of Medical Ultrasonics - Chronic liver disease is still a major problem because disease progression will ultimately lead to liver cirrhosis. Portal hypertension is the hallmark in advanced...  相似文献   
13.
14.
15.
16.
17.
18.
19.
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.  相似文献   
20.

The exercise pressor reflex is a feedback mechanism engaged upon stimulation of mechano- and metabosensitive skeletal muscle afferents. Activation of these afferents elicits a reflex increase in heart rate, blood pressure, and ventilation in an intensity-dependent manner. Consequently, the exercise pressor reflex has been postulated to be one of the principal mediators of the cardiorespiratory responses to exercise. In this updated review, we will discuss classical and recent advancements in our understating of the exercise pressor reflex function in both human and animal models. Particular attention will be paid to the afferent mechanisms and pathways involved during its activation, its effects on different target organs, its potential role in the abnormal cardiovascular response to exercise in diseased states, and the impact of age and biological sex on these responses. Finally, we will highlight some unanswered questions in the literature that may inspire future investigations in the field.

  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-23

京公网安备 11010802026262号