收费全文 | 16956篇 |
免费 | 2027篇 |
国内免费 | 172篇 |
耳鼻咽喉 | 47篇 |
儿科学 | 810篇 |
妇产科学 | 1367篇 |
基础医学 | 826篇 |
口腔科学 | 81篇 |
临床医学 | 1393篇 |
内科学 | 4884篇 |
皮肤病学 | 60篇 |
神经病学 | 851篇 |
特种医学 | 112篇 |
外国民族医学 | 1篇 |
外科学 | 2286篇 |
综合类 | 1056篇 |
一般理论 | 2篇 |
预防医学 | 3224篇 |
眼科学 | 37篇 |
药学 | 568篇 |
6篇 | |
中国医学 | 50篇 |
肿瘤学 | 1494篇 |
2024年 | 38篇 |
2023年 | 486篇 |
2022年 | 726篇 |
2021年 | 1163篇 |
2020年 | 909篇 |
2019年 | 959篇 |
2018年 | 901篇 |
2017年 | 804篇 |
2016年 | 801篇 |
2015年 | 746篇 |
2014年 | 1058篇 |
2013年 | 1458篇 |
2012年 | 730篇 |
2011年 | 796篇 |
2010年 | 596篇 |
2009年 | 684篇 |
2008年 | 722篇 |
2007年 | 693篇 |
2006年 | 662篇 |
2005年 | 498篇 |
2004年 | 481篇 |
2003年 | 387篇 |
2002年 | 325篇 |
2001年 | 288篇 |
2000年 | 211篇 |
1999年 | 200篇 |
1998年 | 188篇 |
1997年 | 182篇 |
1996年 | 163篇 |
1995年 | 142篇 |
1994年 | 136篇 |
1993年 | 124篇 |
1992年 | 111篇 |
1991年 | 88篇 |
1990年 | 90篇 |
1989年 | 78篇 |
1988年 | 79篇 |
1987年 | 62篇 |
1986年 | 83篇 |
1985年 | 73篇 |
1984年 | 56篇 |
1983年 | 37篇 |
1982年 | 32篇 |
1981年 | 23篇 |
1980年 | 14篇 |
1979年 | 22篇 |
1978年 | 11篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 6篇 |
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Methods: Using the Schedule for Clinical Assessment in Neuropsychiatry, tedium vitae was assessed in 130 stroke survivors attending rehabilitation in a large Nigerian university hospital. Global cognitive and executive dysfunctions were evaluated, respectively, using the Mini Mental State Examination and the modi?ed Indiana University Token test. All participants had their index stroke 3 to 24 months before recruitment into the study. We also examined a comparative group of 130 age, gender, and education matched apparently normal persons who were unrelated to the stroke survivors. Associations were explored using univariate and multivariate logistic regression analyses.
Results: Tedium vitae was experienced by 16 (12.3%) stroke survivors compared with 5 (3.9%) in the comparative group (O. R = 3.5, 95% C. I = 1.3–9.9, p = 0.018). Among stroke survivors, those who were retired were more likely to experience tedium vitae (56.2%, p = 0.045). In analyses adjusting for the effect of systemic hypertension, cognitive dysfunction, retirement and marital separation, there was a 3.5-fold increase in the odds of experiencing tedium vitae after surviving a stroke (O. R = 3.5, 95% C. I = 1.1–11.6, p = 0.042).
Conclusions: Tedium vitae is a common suicidal experience after stroke and may be among the earliest perceptible pointer to impending poststroke suicide. It is easy to assess and may be less costly to obtain an adequate sample size in studies aiming to understand the phenomenon of suicide in the stroke population. 相似文献