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   3259972篇
  免费   278564篇
  国内免费   13336篇
医药卫生   3551872篇
  2021年   52216篇
  2020年   35101篇
  2019年   57970篇
  2018年   70911篇
  2017年   53714篇
  2016年   59471篇
  2015年   73685篇
  2014年   107962篇
  2013年   173147篇
  2012年   88402篇
  2011年   87622篇
  2010年   115726篇
  2009年   120481篇
  2008年   74519篇
  2007年   76991篇
  2006年   88084篇
  2005年   83069篇
  2004年   84885篇
  2003年   75950篇
  2002年   65675篇
  2001年   107148篇
  2000年   100004篇
  1999年   98923篇
  1998年   59250篇
  1997年   57043篇
  1996年   54725篇
  1995年   55608篇
  1994年   49624篇
  1993年   46349篇
  1992年   67652篇
  1991年   64308篇
  1990年   61298篇
  1989年   60366篇
  1988年   55299篇
  1987年   53854篇
  1986年   51058篇
  1985年   50800篇
  1984年   46391篇
  1983年   42288篇
  1982年   40340篇
  1981年   37941篇
  1980年   35858篇
  1979年   37334篇
  1978年   33039篇
  1977年   30920篇
  1976年   27778篇
  1975年   26732篇
  1974年   26987篇
  1973年   26001篇
  1972年   24497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