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   1084014篇
  免费   76264篇
  国内免费   1749篇
耳鼻咽喉   15078篇
儿科学   29363篇
妇产科学   26545篇
基础医学   153524篇
口腔科学   35322篇
临床医学   91780篇
内科学   217288篇
皮肤病学   23201篇
神经病学   84944篇
特种医学   41455篇
外国民族医学   105篇
外科学   171008篇
综合类   19312篇
现状与发展   2篇
一般理论   291篇
预防医学   77990篇
眼科学   24084篇
药学   81847篇
  3篇
中国医学   2795篇
肿瘤学   66090篇
  2021年   8957篇
  2019年   9084篇
  2018年   13347篇
  2017年   10265篇
  2016年   10813篇
  2015年   12465篇
  2014年   16960篇
  2013年   23740篇
  2012年   33795篇
  2011年   35159篇
  2010年   19954篇
  2009年   18822篇
  2008年   32413篇
  2007年   34085篇
  2006年   34209篇
  2005年   33370篇
  2004年   32058篇
  2003年   30467篇
  2002年   28274篇
  2001年   58898篇
  2000年   60668篇
  1999年   50562篇
  1998年   12083篇
  1997年   10593篇
  1996年   10709篇
  1995年   9885篇
  1994年   9203篇
  1993年   8451篇
  1992年   37776篇
  1991年   36138篇
  1990年   34773篇
  1989年   33894篇
  1988年   30824篇
  1987年   29946篇
  1986年   27918篇
  1985年   26701篇
  1984年   18945篇
  1983年   16042篇
  1982年   8300篇
  1979年   16613篇
  1978年   11142篇
  1977年   9485篇
  1976年   8244篇
  1975年   9124篇
  1974年   10960篇
  1973年   10361篇
  1972年   9772篇
  1971年   9233篇
  1970年   8840篇
  1969年   8338篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
2.
3.
4.
5.
6.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
7.
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2.  相似文献   
8.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
9.
10.
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