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   1046717篇
  免费   73002篇
  国内免费   2295篇
耳鼻咽喉   14358篇
儿科学   27498篇
妇产科学   25792篇
基础医学   147898篇
口腔科学   31665篇
临床医学   89931篇
内科学   209575篇
皮肤病学   21394篇
神经病学   82972篇
特种医学   41330篇
外国民族医学   102篇
外科学   168842篇
综合类   19712篇
现状与发展   1篇
一般理论   283篇
预防医学   67904篇
眼科学   23166篇
药学   80963篇
  6篇
中国医学   2710篇
肿瘤学   65912篇
  2021年   8297篇
  2019年   8287篇
  2018年   11821篇
  2017年   9237篇
  2016年   10167篇
  2015年   11543篇
  2014年   15509篇
  2013年   22330篇
  2012年   30834篇
  2011年   31869篇
  2010年   19068篇
  2009年   18054篇
  2008年   30458篇
  2007年   31888篇
  2006年   32240篇
  2005年   30849篇
  2004年   30131篇
  2003年   28943篇
  2002年   28325篇
  2001年   58187篇
  2000年   59950篇
  1999年   49728篇
  1998年   11963篇
  1997年   10435篇
  1996年   10455篇
  1995年   9755篇
  1994年   9007篇
  1993年   8282篇
  1992年   37140篇
  1991年   35552篇
  1990年   34141篇
  1989年   33222篇
  1988年   30265篇
  1987年   29386篇
  1986年   27394篇
  1985年   26134篇
  1984年   18572篇
  1983年   15820篇
  1982年   8236篇
  1979年   16331篇
  1978年   11004篇
  1977年   9411篇
  1976年   8188篇
  1975年   9047篇
  1974年   10927篇
  1973年   10311篇
  1972年   9755篇
  1971年   9223篇
  1970年   8760篇
  1969年   8266篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Whereas there is evidence that interpersonal communication, or conversation, influences predictors of alcohol consumption, the role of involvement in conversation effects remains unclear. This study explored how three aspects of involvement (topical relevance, or how relevant the topic of alcohol is; conversational relevance, or how relevant a conversation about alcohol is; and conversational effort, or how much effort people put into such a conversation), influence conversation effects. After assessing topical relevance, 46 same-sex dyads were requested to talk about the negative consequences of heavy drinking. Within each dyad, one participant was asked to take on an active talking role and the other participant a passive listening role. Next, conversational relevance, effort, and predictors of heavy drinking were measured. Results showed that participants who drank more alcohol found the topic of heavy drinking more relevant. This topical relevance increased conversational relevance and conversational effort. Conversational effort further increased when a talking role was assigned. Furthermore, participants who put more effort in the conversation and found it more relevant had more positive norms, identified more strongly with alcohol, and had higher intentions to drink. These findings suggest that more involvement in an alcohol-related conversation does not always lead to desirable outcomes.  相似文献   
2.
3.

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   
4.
5.
6.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
7.
8.
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