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   2282537篇
  免费   155883篇
  国内免费   3134篇
耳鼻咽喉   31568篇
儿科学   74708篇
妇产科学   61868篇
基础医学   331821篇
口腔科学   63943篇
临床医学   206613篇
内科学   435474篇
皮肤病学   51342篇
神经病学   180399篇
特种医学   88233篇
外国民族医学   481篇
外科学   335829篇
综合类   45554篇
现状与发展   3篇
一般理论   816篇
预防医学   172889篇
眼科学   52514篇
药学   173886篇
  12篇
中国医学   4780篇
肿瘤学   128821篇
  2019年   17210篇
  2018年   24774篇
  2017年   19288篇
  2016年   21968篇
  2015年   24911篇
  2014年   33484篇
  2013年   50036篇
  2012年   69051篇
  2011年   72603篇
  2010年   42526篇
  2009年   39941篇
  2008年   68496篇
  2007年   73605篇
  2006年   73814篇
  2005年   71906篇
  2004年   68906篇
  2003年   66363篇
  2002年   64198篇
  2001年   107964篇
  2000年   110274篇
  1999年   92777篇
  1998年   24980篇
  1997年   22311篇
  1996年   22279篇
  1995年   20878篇
  1994年   19314篇
  1993年   18144篇
  1992年   70874篇
  1991年   68891篇
  1990年   67311篇
  1989年   65047篇
  1988年   59523篇
  1987年   58117篇
  1986年   55172篇
  1985年   51972篇
  1984年   38784篇
  1983年   33353篇
  1982年   19215篇
  1979年   36114篇
  1978年   25567篇
  1977年   22030篇
  1976年   19910篇
  1975年   22048篇
  1974年   26262篇
  1973年   25631篇
  1972年   24454篇
  1971年   22887篇
  1970年   21372篇
  1969年   20364篇
  1968年   18682篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Severe tuberculosis (TB) requiring intensive care unit (ICU) care is rare but commonly known to be of markedly bad prognosis. The present study aimed to describe this condition and to determine the mortality rate and risk factors associated with mortality. Patients with confirmed TB admitted to ICU between 1990 and 2001 were retrospectively identified and enrolled. Clinical, radiological and bacteriological data at admission and during hospital stay were recorded. A multivariate analysis was performed to identify the predictive factors for mortality. A total of 58 TB patients (12 females, mean age 48 yrs) admitted to ICU were included. Mean Acute Physiology and Chronic Health Evaluation (APACHE) II score at admission was 13.1+/-5.6 and 22 of 58 (37.9%) patients required mechanical ventilation. The in-hospital mortality was 15 of 58 (25.9%); 13 (22.4%) patients died in the ICU. The mean survival of patients who died was 53.6 days (range 1-229), with 50% of the patients dying within the first 32 days. The factors independently associated with mortality were: acute renal failure, need for mechanical ventilation, chronic pancreatitis, sepsis, acute respiratory distress syndrome, and nosocomial pneumonia. These data indicate a high mortality of patients with tuberculosis requiring intensive care unit care and identifies new independently associated risk factors.  相似文献   
32.
33.
Low molecular weight heparins are widely used in the prophylaxis and treatment of thrombotic disorders. The effect of low molecular weight heparins on coagulation was examined ultrastructurally in an animal model. A test and a control group was formed, each consisting of five rabbits. Nadroparine (225 Institute of Chaoy Unit/kg twice daily) was applied to the test group for 10 days. The control group received 1 ml saline solution subcutaneously. Blood and vascular tissue samples collected at the end of the 10th day were evaluated under a JEM 100 B electron microscope. Platelet degranulation and agglutination was observed in the control group. Fibrin materials were detected in the cytoplasms and surroundings of degranulated platelets. Erythrocyte accumulation was remarkable on the vascular endothelium with intact coagulation periods. In the test group, outer membranes of platelets, hyalomere, and granular structures in the granulomeres were detected to be nearly intact. There were rare erythrocytes in the large vascular lumens. The aggregation phase had occurred but no agglutination was detected. Nadroparine seems to preserve consistency of lipoprotein membranes of platelets and granular structures containing enzymes, which contribute to the coagulation mechanisms.  相似文献   
34.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
35.
36.
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma.  相似文献   
37.
38.
39.
Abstrakt 1. Ein nicht ausgefülltes und nicht unterschriebenes Aufkl?rungsformular in der Krankenakte bildet ein Indiz nicht für, sondern gegen die Durchführung eines Aufkl?rungsgespr?chs. 2. Wenn vor dem ?rztlichen Eingriff überhaupt keine Aufkl?rung erfolgt, genügt für den Beginn der Verj?hrung eines auf eine Aufkl?rungspflichtverletzung gestützten Anspruchs die Kenntnis vom Eintritt schwerwiegender Komplikationen. Nicht erforderlich ist das Wissen, dass sich ein typisches Risiko des Eingriffs verwirklicht hat.  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