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   2707539篇
  免费   241996篇
  国内免费   12734篇
耳鼻咽喉   37354篇
儿科学   85901篇
妇产科学   68625篇
基础医学   451980篇
口腔科学   71645篇
临床医学   241620篇
内科学   461868篇
皮肤病学   78756篇
神经病学   236955篇
特种医学   107059篇
外国民族医学   68篇
外科学   430227篇
综合类   86976篇
现状与发展   23篇
一般理论   2123篇
预防医学   230756篇
眼科学   61122篇
药学   181226篇
  22篇
中国医学   8317篇
肿瘤学   119646篇
  2022年   22643篇
  2021年   54347篇
  2020年   34682篇
  2019年   57563篇
  2018年   69502篇
  2017年   52805篇
  2016年   58157篇
  2015年   72778篇
  2014年   106846篇
  2013年   171832篇
  2012年   71763篇
  2011年   68758篇
  2010年   111169篇
  2009年   117108篇
  2008年   56238篇
  2007年   56694篇
  2006年   68360篇
  2005年   64093篇
  2004年   66526篇
  2003年   57891篇
  2002年   47891篇
  2001年   64022篇
  2000年   55397篇
  1999年   63431篇
  1998年   60764篇
  1997年   59739篇
  1996年   57392篇
  1995年   52920篇
  1994年   47144篇
  1993年   44159篇
  1992年   41459篇
  1991年   39323篇
  1990年   36651篇
  1989年   36956篇
  1988年   34384篇
  1987年   33460篇
  1986年   31896篇
  1985年   33077篇
  1984年   34365篇
  1983年   32750篇
  1982年   36800篇
  1981年   35120篇
  1980年   33184篇
  1979年   26633篇
  1978年   26771篇
  1977年   25378篇
  1976年   23053篇
  1975年   21002篇
  1974年   20010篇
  1973年   19295篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
162.
163.

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   
164.
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   
165.
166.
167.
168.
169.
170.

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   
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