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   4351234篇
  免费   349682篇
  国内免费   14707篇
耳鼻咽喉   60420篇
儿科学   139516篇
妇产科学   114325篇
基础医学   667431篇
口腔科学   118080篇
临床医学   397273篇
内科学   791141篇
皮肤病学   107816篇
神经病学   368623篇
特种医学   169572篇
外国民族医学   753篇
外科学   656500篇
综合类   121290篇
现状与发展   24篇
一般理论   2614篇
预防医学   360656篇
眼科学   101006篇
药学   308064篇
  26篇
中国医学   11959篇
肿瘤学   218534篇
  2021年   56368篇
  2020年   35922篇
  2019年   58934篇
  2018年   74572篇
  2017年   57126篇
  2016年   63293篇
  2015年   76229篇
  2014年   110479篇
  2013年   176176篇
  2012年   124742篇
  2011年   129512篇
  2010年   126171篇
  2009年   127751篇
  2008年   115228篇
  2007年   122511篇
  2006年   131299篇
  2005年   125364篇
  2004年   126665篇
  2003年   116861篇
  2002年   106080篇
  2001年   166983篇
  2000年   162046篇
  1999年   148704篇
  1998年   71675篇
  1997年   67625篇
  1996年   65638篇
  1995年   61066篇
  1994年   54987篇
  1993年   51025篇
  1992年   106625篇
  1991年   101392篇
  1990年   97253篇
  1989年   94827篇
  1988年   87152篇
  1987年   85322篇
  1986年   80207篇
  1985年   78373篇
  1984年   65408篇
  1983年   58219篇
  1982年   47213篇
  1981年   43872篇
  1980年   41084篇
  1979年   55118篇
  1978年   44766篇
  1977年   39991篇
  1976年   36851篇
  1975年   36819篇
  1974年   39623篇
  1973年   37762篇
  1972年   35363篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
153.

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   
154.
Erosive pustular dermatosis of the scalp (EPDS) is an uncommon chronic inflammatory response to scalp trauma that usually resolves with cicatricial alopecia. It most commonly affects elderly patients with a history of actinic damage. Herein, we describe a 16‐year‐old girl with acrofacial dysostosis type 1 presenting after surgery with crusting purulent scalp lesions, whose clinical presentation and histopathologic findings were consistent with EPDS. A review of the literature on EPDS in children is also detailed.  相似文献   
155.
156.
157.
158.
159.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
160.
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