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   3621184篇
  免费   258495篇
  国内免费   11273篇
耳鼻咽喉   48254篇
儿科学   117807篇
妇产科学   99251篇
基础医学   514157篇
口腔科学   100695篇
临床医学   336604篇
内科学   707850篇
皮肤病学   83523篇
神经病学   301902篇
特种医学   134833篇
外国民族医学   1104篇
外科学   524833篇
综合类   73062篇
现状与发展   6篇
一般理论   1397篇
预防医学   293888篇
眼科学   81322篇
药学   265516篇
  13篇
中国医学   8184篇
肿瘤学   196751篇
  2021年   30101篇
  2019年   31510篇
  2018年   45906篇
  2017年   34222篇
  2016年   38531篇
  2015年   43469篇
  2014年   58335篇
  2013年   88990篇
  2012年   122477篇
  2011年   129172篇
  2010年   75775篇
  2009年   70214篇
  2008年   118465篇
  2007年   125638篇
  2006年   126273篇
  2005年   121432篇
  2004年   116069篇
  2003年   111362篇
  2002年   107298篇
  2001年   162275篇
  2000年   166629篇
  1999年   140697篇
  1998年   40952篇
  1997年   36322篇
  1996年   36275篇
  1995年   34964篇
  1994年   32248篇
  1993年   30330篇
  1992年   110194篇
  1991年   106483篇
  1990年   103257篇
  1989年   99319篇
  1988年   91325篇
  1987年   89469篇
  1986年   84401篇
  1985年   80630篇
  1984年   60387篇
  1983年   51518篇
  1982年   30697篇
  1979年   54049篇
  1978年   38355篇
  1977年   32325篇
  1976年   30482篇
  1975年   32166篇
  1974年   38514篇
  1973年   36953篇
  1972年   34539篇
  1971年   32155篇
  1970年   29828篇
  1969年   28348篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
To determine percent of patients without malignancy and ≤ 40 years of age with high cumulative radiation doses through recurrent CT exams and assess imaging appropriateness. From the cohort of patients who received cumulative effective dose (CED) of ≥ 100 mSv over a 5-year period, a sub-set was identified with non-malignant disease. The top 50 clinical indications leading to multiple CTs were determined. Clinical decision support (CDS) system scores were analyzed using a widely adopted standard of 1–3 (red) as “not usually appropriate,” 4–6 (yellow) “may or may not be appropriate,” and 7–9 (green) “usually appropriate.” Clinicians reviewed patient records to assess compliance with appropriate use criteria (AUC). 9.6% of patients in our series were with non-malignant conditions and 1.4% with age ≤ 40 years. CDS scores (rounded) were 2% red, 38% yellow, 27% green, and 33% unscored CTs. Clinical society guidelines for CT exams, wherever available, were followed in 87.5 to 100% of cases. AUCs were not available for several clinical indications as also referral guidelines for serial CT imaging. More than half of CT exams were unrelated to follow-up of a primary chronic disease. We are faced with a situation wherein patients in age ≤ 40 years require or are thought to require many CT exams over the course of a few years but the radiation risk creates concern. There is a fair number of conditions for which AUC are not available. Suggested solutions include development of CT scanners with lesser radiation dose and further development of appropriateness criteria.  相似文献   
83.
84.
85.
86.

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   
87.
88.
89.
90.
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