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   2367929篇
  免费   184059篇
  国内免费   18316篇
耳鼻咽喉   31224篇
儿科学   68622篇
妇产科学   63189篇
基础医学   330151篇
口腔科学   65190篇
临床医学   219829篇
内科学   460665篇
皮肤病学   50852篇
神经病学   185604篇
特种医学   90489篇
外国民族医学   631篇
外科学   355799篇
综合类   79823篇
现状与发展   52篇
一般理论   714篇
预防医学   173664篇
眼科学   55354篇
药学   179681篇
  168篇
中国医学   15524篇
肿瘤学   143079篇
  2021年   25938篇
  2020年   17597篇
  2019年   23135篇
  2018年   30447篇
  2017年   24298篇
  2016年   26086篇
  2015年   31911篇
  2014年   43182篇
  2013年   57656篇
  2012年   79445篇
  2011年   84644篇
  2010年   50340篇
  2009年   46519篇
  2008年   74713篇
  2007年   78226篇
  2006年   78882篇
  2005年   76924篇
  2004年   70492篇
  2003年   66976篇
  2002年   64337篇
  2001年   118315篇
  2000年   121529篇
  1999年   102301篇
  1998年   28807篇
  1997年   26172篇
  1996年   25481篇
  1995年   24088篇
  1994年   21853篇
  1993年   19841篇
  1992年   75569篇
  1991年   72170篇
  1990年   69252篇
  1989年   66639篇
  1988年   60954篇
  1987年   59441篇
  1986年   55229篇
  1985年   52791篇
  1984年   38978篇
  1983年   32863篇
  1982年   18750篇
  1979年   34251篇
  1978年   23575篇
  1977年   19882篇
  1976年   18071篇
  1975年   19052篇
  1974年   23114篇
  1973年   22102篇
  1972年   20798篇
  1971年   19234篇
  1970年   18335篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.

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   
52.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
53.
54.
55.
56.
57.
58.
59.
Acne vulgaris (acne) is a chronic inflammatory disease of the sebaceous gland, characterized by follicular hyperkeratinization, excessive colonization by Propionibacterium acnes (Pacnes) as well as immune reactions and inflammation. Despite an armamentarium of topical treatments available including benzoyl peroxide, retinoids and azelaic acid, topical antibiotics in monotherapies, especially erythromycin and clindamycin, are still used in Europe to treat acne. This intensive use led to antimicrobial‐resistant P. acnes and staphylococci strains becoming one of the main health issues worldwide. This is an update on the current topical acne treatments available in Europe, their mechanism of action, their potential to induce antimicrobial resistance and their clinical efficacy and safety.  相似文献   
60.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
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