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   2803311篇
  免费   198603篇
  国内免费   4170篇
耳鼻咽喉   37866篇
儿科学   90201篇
妇产科学   74093篇
基础医学   416439篇
口腔科学   74917篇
临床医学   253738篇
内科学   541336篇
皮肤病学   60883篇
神经病学   220960篇
特种医学   104125篇
外国民族医学   545篇
外科学   420999篇
综合类   55562篇
现状与发展   14篇
一般理论   1157篇
预防医学   221221篇
眼科学   65484篇
药学   208727篇
  12篇
中国医学   5493篇
肿瘤学   152312篇
  2021年   23448篇
  2019年   23798篇
  2018年   32787篇
  2017年   24764篇
  2016年   27643篇
  2015年   31305篇
  2014年   44146篇
  2013年   66404篇
  2012年   92386篇
  2011年   99096篇
  2010年   58474篇
  2009年   54803篇
  2008年   93074篇
  2007年   99341篇
  2006年   99583篇
  2005年   96998篇
  2004年   93112篇
  2003年   89579篇
  2002年   86601篇
  2001年   121646篇
  2000年   124273篇
  1999年   104927篇
  1998年   31909篇
  1997年   27949篇
  1996年   28123篇
  1995年   26442篇
  1994年   24334篇
  1993年   22953篇
  1992年   80556篇
  1991年   79291篇
  1990年   77517篇
  1989年   74669篇
  1988年   68749篇
  1987年   67691篇
  1986年   63280篇
  1985年   60992篇
  1984年   45825篇
  1983年   39144篇
  1982年   23655篇
  1979年   41946篇
  1978年   30328篇
  1977年   25110篇
  1976年   24347篇
  1975年   26478篇
  1974年   31284篇
  1973年   29808篇
  1972年   27809篇
  1971年   26350篇
  1970年   24277篇
  1969年   23148篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
31.
32.
33.
34.
35.
36.
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   
37.
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.
OBJECTIVE: To illustrate the safety and efficacy of the endoscopic laser approach for cricopharyngeal myotomy (CPM) compared to the traditional transcervical approach. STUDY DESIGN AND SETTING: Retrospective chart review of 22 patients undergoing CPM from 1996 to 2003 at the Mayo Clinic, Jacksonville. RESULTS: The laser CPM technique was used in 14 patients, and an open approach in 8. The mean hospital stay and operative times were shorter for the laser group. Functional outcome analyses showed improvement in both groups. There were no major complications in the laser group, while 1 patient in the transcervical group had a pharyngocutaneous fistula. CONCLUSIONS: The laser technique is at least as effective as the transcervical approach for CPM to improve dysphagia symptoms in the properly selected patient, with a low risk of major complications. SIGNIFICANCE: In this report, we provide the reader with data to support the safety and efficacy of laser CPM. EBM rating: B-3b.  相似文献   
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