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   2696077篇
  免费   185846篇
  国内免费   7588篇
耳鼻咽喉   38027篇
儿科学   88938篇
妇产科学   76617篇
基础医学   386644篇
口腔科学   72561篇
临床医学   239377篇
内科学   534940篇
皮肤病学   67764篇
神经病学   220897篇
特种医学   104351篇
外国民族医学   736篇
外科学   401678篇
综合类   50742篇
现状与发展   5篇
一般理论   972篇
预防医学   199751篇
眼科学   61443篇
药学   191883篇
  8篇
中国医学   5376篇
肿瘤学   146801篇
  2019年   20641篇
  2018年   29421篇
  2017年   22721篇
  2016年   26420篇
  2015年   31768篇
  2014年   43123篇
  2013年   63992篇
  2012年   82711篇
  2011年   86901篇
  2010年   53589篇
  2009年   51877篇
  2008年   81699篇
  2007年   86375篇
  2006年   88430篇
  2005年   84294篇
  2004年   81024篇
  2003年   77288篇
  2002年   73685篇
  2001年   128917篇
  2000年   131760篇
  1999年   111018篇
  1998年   31988篇
  1997年   28672篇
  1996年   29224篇
  1995年   28508篇
  1994年   26260篇
  1993年   24563篇
  1992年   86313篇
  1991年   82579篇
  1990年   79670篇
  1989年   76836篇
  1988年   70173篇
  1987年   68752篇
  1986年   64250篇
  1985年   61068篇
  1984年   45602篇
  1983年   38461篇
  1982年   23096篇
  1981年   20652篇
  1979年   39612篇
  1978年   28169篇
  1977年   23823篇
  1976年   22010篇
  1975年   23447篇
  1974年   27441篇
  1973年   26076篇
  1972年   24338篇
  1971年   22473篇
  1970年   20677篇
  1969年   20069篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The present study compared four different sites and conditions for the measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in 38 spontaneous breathing tracheotomised patients. Of the patients, 28 had chronic obstructive pulmonary disease (COPD). The four different conditions were: 1) through a cuff inflated cannula (condition A); 2) through the mouth with a deflated cannula (condition B); 3) through the mouth with a phonetic uncuffed cannula (condition C); and 4) through the mouth after stoma closure (condition D). Five trials in each condition were performed using a standardised method. The measurement of both MIP and MEP differed significantly depending on the condition of measurement. MIP taken in condition A was significantly higher when compared with conditions B, C and D. MEP in condition A was significantly higher when compared with condition B and D. In condition A the highest frequency of the best measurement of MIP and MEP was observed at the fourth and fifth effort, respectively. The same results were obtained after the selection of only COPD patients. In conclusion, respiratory muscle assessment differs significantly depending on measurement condition. Measurement through inflated cannula tracheotomy yields higher values of both maximal inspiratory and maximal expiratory pressure.  相似文献   
42.
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   
43.
    
Ohne Zusammenfassung  相似文献   
44.
45.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  相似文献   
46.
47.
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   
48.
49.
50.
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