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   52635篇
  免费   3864篇
  国内免费   114篇
耳鼻咽喉   605篇
儿科学   1861篇
妇产科学   1237篇
基础医学   6500篇
口腔科学   748篇
临床医学   8163篇
内科学   9501篇
皮肤病学   618篇
神经病学   5090篇
特种医学   1353篇
外国民族医学   1篇
外科学   5571篇
综合类   621篇
一般理论   60篇
预防医学   6887篇
眼科学   710篇
药学   3292篇
中国医学   59篇
肿瘤学   3736篇
  2023年   378篇
  2022年   530篇
  2021年   1059篇
  2020年   728篇
  2019年   1147篇
  2018年   1347篇
  2017年   1021篇
  2016年   1080篇
  2015年   1175篇
  2014年   1633篇
  2013年   2579篇
  2012年   3674篇
  2011年   3873篇
  2010年   2062篇
  2009年   1929篇
  2008年   3376篇
  2007年   3439篇
  2006年   3430篇
  2005年   3292篇
  2004年   3059篇
  2003年   2712篇
  2002年   2595篇
  2001年   722篇
  2000年   672篇
  1999年   665篇
  1998年   577篇
  1997年   474篇
  1996年   374篇
  1995年   335篇
  1994年   330篇
  1993年   304篇
  1992年   410篇
  1991年   404篇
  1990年   418篇
  1989年   373篇
  1988年   324篇
  1987年   309篇
  1986年   327篇
  1985年   303篇
  1984年   293篇
  1983年   234篇
  1982年   209篇
  1981年   191篇
  1980年   167篇
  1979年   192篇
  1978年   158篇
  1977年   159篇
  1976年   153篇
  1974年   142篇
  1972年   132篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
1.
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   
2.
3.
4.
5.
6.
7.
8.
9.
Obtaining accurate assessment data from adolescents in treatment aids clinical decision making and facilitates more accurate outcome evaluations. However, findings could be biased due to underreported substance use and mental health symptoms. This article compares self-reports of youth in non-White matched client–assessor dyads and those in nonmatched dyads. There were no differences on self-reported substance use, but matched youth reported significantly fewer attention deficit/hyperactivity disorder symptoms versus the comparison group. One possible reason for these findings is the effect of in-group stereotype threat. Future studies should examine the potential effect that in-group stereotyping and perceived racism have on the therapeutic relationship.  相似文献   
10.
Recent work suggests that while voluntary episodic memory declines with age, involuntary episodic memory, which comes to mind spontaneously without intention, remains relatively intact. However, the neurophysiology underlying these differences has yet to be established. The current study used electroencephalography (EEG) to investigate voluntary and involuntary retrieval in older and younger adults. Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization cover task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later reported which sounds brought the paired picture to mind during the localization task. Reaction times on the localization task were slower for voluntary than involuntary retrieval and for paired than unpaired sounds, possibly reflecting increased attentional demands of voluntary retrieval and interference from reactivation of the associated pictures respectively. For the EEG analyses, young adults showed greater alpha event-related desynchronization (ERD) during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD regardless of intention. Additionally, older adults showed greater ERD for paired than unpaired sounds at occipital sites, likely reflecting visual reactivation of the associated pictures. Young adults did not show this alpha ERD memory effect. Taken together, these data suggest that involuntary memory is largely preserved with age, but this may be due to older adults' greater recruitment of top-down control even when demand for such control is limited.  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