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   2476930篇
  免费   197068篇
  国内免费   5309篇
耳鼻咽喉   36361篇
儿科学   80458篇
妇产科学   64678篇
基础医学   351013篇
口腔科学   65022篇
临床医学   234562篇
内科学   496119篇
皮肤病学   58230篇
神经病学   197596篇
特种医学   93370篇
外国民族医学   489篇
外科学   388058篇
综合类   47779篇
现状与发展   84篇
一般理论   854篇
预防医学   188786篇
眼科学   57277篇
药学   176072篇
  11篇
中国医学   4583篇
肿瘤学   137905篇
  2021年   21588篇
  2019年   21326篇
  2018年   33232篇
  2017年   26487篇
  2016年   29612篇
  2015年   32574篇
  2014年   48996篇
  2013年   67051篇
  2012年   79362篇
  2011年   84145篇
  2010年   55768篇
  2009年   56402篇
  2008年   79551篇
  2007年   83005篇
  2006年   85848篇
  2005年   81035篇
  2004年   76999篇
  2003年   73414篇
  2002年   71137篇
  2001年   111916篇
  2000年   113996篇
  1999年   96165篇
  1998年   29986篇
  1997年   26471篇
  1996年   26740篇
  1995年   25331篇
  1994年   22441篇
  1993年   20964篇
  1992年   73142篇
  1991年   71268篇
  1990年   69285篇
  1989年   66621篇
  1988年   61138篇
  1987年   59875篇
  1986年   55974篇
  1985年   53600篇
  1984年   39766篇
  1983年   33825篇
  1982年   20279篇
  1979年   36116篇
  1978年   25928篇
  1977年   21549篇
  1976年   20541篇
  1975年   22054篇
  1974年   26341篇
  1973年   25015篇
  1972年   23471篇
  1971年   22191篇
  1970年   20461篇
  1969年   19382篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
33.
34.
35.
36.
37.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  相似文献   
38.
AIM: To evaluate whether the introduction of a strict protocol approach based on the systemic evaluation of critically ill pregnant women with complications of abortion affected outcome. SETTING: Indigent South Africans managed in the regional and tertiary hospitals of the Pretoria Academic Complex. METHOD: Since 1997 a standard definition of severe acute maternal morbidity (SAMM) has been used in the Pretoria Academic Complex. All cases of SAMM and maternal deaths were entered on the Maternal Morbidity and Mortality Audit System programme. A comparison of outcome of severely ill women who had complications of abortion was made between 1997-1998 (original protocol) and 2002-2004 (strict protocol). OUTCOME MEASURES: The mortality index and prevalence of organ system failure or dysfunction. RESULTS: In 1997-1998 there were 43 women with SAMM who survived and a further 10 maternal deaths due to complications of abortion, compared with 107 women with SAMM and 7 maternal deaths during 2002-2004. The mortality index declined from 18.9% in 1997-1998 to 6.1% in 2002-2004 (p = 0.02, odds ratio 0.28, 95% confidence limits 0.10 - 0.79). Significantly more women had hypovolaemic shock in 2002-2004 compared with 1997-1998 (54.4% v. 35.8%, p = 0.04), but fewer women had immune system failure including septic shock (18.4% v. 47.2%, p = 0.0002) and metabolic dysfunction (0 v. 5.7%, p = 0.03) and there was a trend to less renal failure (10.5% v. 22.6%, p = 0.06) and cardiac failure (4.4% v. 13.2%, p = 0.08). CONCLUSION: The strict protocol approach based on systemic evaluation in managing critically ill pregnant women with complications of abortion, coupled with an intensive, regular feedback mechanism, has been associated with a reduction in the mortality index.  相似文献   
39.
40.
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