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   4324905篇
  免费   346340篇
  国内免费   14199篇
耳鼻咽喉   59833篇
儿科学   137987篇
妇产科学   112808篇
基础医学   664758篇
口腔科学   115908篇
临床医学   394073篇
内科学   782779篇
皮肤病学   107673篇
神经病学   361539篇
特种医学   168399篇
外国民族医学   515篇
外科学   664247篇
综合类   120746篇
现状与发展   24篇
一般理论   2674篇
预防医学   361712篇
眼科学   101782篇
药学   302873篇
  26篇
中国医学   11500篇
肿瘤学   213588篇
  2021年   57047篇
  2020年   36266篇
  2019年   59557篇
  2018年   75460篇
  2017年   57633篇
  2016年   63958篇
  2015年   76761篇
  2014年   111591篇
  2013年   177483篇
  2012年   131058篇
  2011年   137748篇
  2010年   128986篇
  2009年   129642篇
  2008年   122972篇
  2007年   131402篇
  2006年   139457篇
  2005年   134586篇
  2004年   134260篇
  2003年   123989篇
  2002年   112931篇
  2001年   150305篇
  2000年   145023篇
  1999年   134821篇
  1998年   70748篇
  1997年   66692篇
  1996年   64782篇
  1995年   60015篇
  1994年   54110篇
  1993年   50337篇
  1992年   96291篇
  1991年   92854篇
  1990年   89216篇
  1989年   86996篇
  1988年   80161篇
  1987年   78654篇
  1986年   73999篇
  1985年   73141篇
  1984年   61822篇
  1983年   55578篇
  1982年   46175篇
  1981年   43265篇
  1980年   40631篇
  1979年   53192篇
  1978年   44127篇
  1977年   38966篇
  1976年   36357篇
  1975年   36336篇
  1974年   39470篇
  1973年   37696篇
  1972年   35288篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
151.

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   
152.
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   
153.
154.
155.
156.
157.

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   
158.
159.
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