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   2416757篇
  免费   197366篇
  国内免费   4402篇
耳鼻咽喉   34894篇
儿科学   73792篇
妇产科学   63637篇
基础医学   339938篇
口腔科学   68466篇
临床医学   219863篇
内科学   477038篇
皮肤病学   48768篇
神经病学   205096篇
特种医学   97221篇
外国民族医学   886篇
外科学   367414篇
综合类   56665篇
现状与发展   1篇
一般理论   1019篇
预防医学   193844篇
眼科学   56399篇
药学   179970篇
  7篇
中国医学   4400篇
肿瘤学   129207篇
  2018年   25174篇
  2017年   19499篇
  2016年   21394篇
  2015年   24202篇
  2014年   34814篇
  2013年   52723篇
  2012年   71690篇
  2011年   75509篇
  2010年   44238篇
  2009年   42493篇
  2008年   71707篇
  2007年   76138篇
  2006年   76902篇
  2005年   74968篇
  2004年   72160篇
  2003年   69761篇
  2002年   68803篇
  2001年   112765篇
  2000年   116798篇
  1999年   98725篇
  1998年   28367篇
  1997年   25957篇
  1996年   25815篇
  1995年   24968篇
  1994年   23471篇
  1993年   21813篇
  1992年   79604篇
  1991年   76566篇
  1990年   73740篇
  1989年   70958篇
  1988年   66010篇
  1987年   64927篇
  1986年   61460篇
  1985年   58538篇
  1984年   44394篇
  1983年   37831篇
  1982年   23147篇
  1981年   20551篇
  1980年   19220篇
  1979年   41365篇
  1978年   29078篇
  1977年   24439篇
  1976年   22882篇
  1975年   24001篇
  1974年   29679篇
  1973年   28079篇
  1972年   26241篇
  1971年   24163篇
  1970年   22760篇
  1969年   21097篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
75.
Liver-related death in human immunodeficiency virus (HIV)-infected individuals is about 10 times higher compared with the general population, and the prevalence of significant liver fibrosis in those with HIV approaches 15%. The present study aimed to assess risk factors for development of hepatic fibrosis in HIV patients receiving a modern combination anti-retroviral therapy (cART).This cross-sectional prospective study included 432 HIV patients, of which 68 (16%) patients were anti-hepatitis C virus (HCV) positive and 23 (5%) were HBsAg positive.Health trajectory including clinical characteristics and liver fibrosis stage assessed by transient elastography were collected at inclusion. Liver stiffness values >7.1 kPa were considered as significant fibrosis, while values >12.5 kPa were defined as severe fibrosis. Logistic regression and Cox regression uni- and multivariate analyses were performed to identify independent factors associated with liver fibrosis.Significant liver fibrosis was detected in 10% of HIV mono-infected, in 37% of HCV co-infected patients, and in 18% of hepatitis B virus co-infected patients. The presence of diabetes mellitus (odds ratio [OR] = 4.6) and FIB4 score (OR = 2.4) were independently associated with presence of significant fibrosis in the whole cohort. Similarly, diabetes mellitus (OR = 5.4), adiposity (OR = 4.6), and the FIB4 score (OR = 3.3) were independently associated with significant fibrosis in HIV mono-infected patients. Importantly, cumulative cART duration protected, whereas persistent HIV viral replication promoted the development of significant liver fibrosis along the duration of HIV infection.Our findings strongly indicate that besides known risk factors like metabolic disorders, HIV may also have a direct effect on fibrogenesis. Successful cART leading to complete suppression of HIV replication might protect from development of liver fibrosis.  相似文献   
76.
77.
Theory: Immersive simulation is a common mode of education for medical students. Observation of clinical simulations prior to participation is believed to be beneficial, though this is often a passive process. Active observation may be more beneficial. Hypotheses: The hypothesis tested in this study was that the active use of a simple checklist during observation of an immersive simulation would result in better participant performance in a subsequent scenario compared with passive observation alone. Methods: Medical students were randomized to either passive or active (with checklist) observation of an immersive simulation involving cardiac arrest prior to participating in their own simulation. Performance measures included time to cardiopulmonary resuscitation (CPR) and time to defibrillation and were compared between first and second scenarios as well as between passive and active observers. Results: Seventy-nine simulations involving 232 students were conducted. Mean time to CPR was 18 seconds (SD = 11.6) for those using the checklist and 24 seconds (SD = 15.8) for those who observed passively (M difference = 6 seconds), t(35) = 1.46, p =.153. Time to defibrillation was 94 seconds (SD = 26.4) for those using the checklist and 92 seconds (SD = 23.8) for those who observed passively (M difference = –2 seconds), t(38) =.21, p =.837. Time to CPR was 24 seconds (SD = 15.8) for passive observers and 31 seconds (SD = 21.0; M difference = 7 seconds), t(35) = 1.13, p =.265, for their first scenario counterparts. Time to CPR was 18 seconds (SD = 11.6) for active observers and 36 seconds (SD = 26.2; M difference = 18 seconds), t(24) = 2.81, p =.010, for their first scenario counterparts. Time to defibrillation was 92 seconds (SD = 23.8) for passive observers and 125 seconds (SD = 32.2; M difference = 33 seconds), t(33) = 3.63, p =.001, for their first scenario counterparts. Time to defibrillation was 94 seconds (SD = 26.4) for the active observers and 132 seconds (SD = 52.9; M difference = 38 seconds), t(28) =.46, p =.008, for their first scenario counterparts. Conclusions: Observation alone leads to improved performance in the management of a simulated cardiac arrest. The active use of a simple skills-based checklist during observation did not appear to improve performance over passive observation alone.  相似文献   
78.
79.
80.
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