收费全文 | 177615篇 |
免费 | 11797篇 |
国内免费 | 703篇 |
医药卫生 | 190115篇 |
2023年 | 638篇 |
2022年 | 680篇 |
2021年 | 2859篇 |
2020年 | 1761篇 |
2019年 | 2885篇 |
2018年 | 3395篇 |
2017年 | 2453篇 |
2016年 | 2859篇 |
2015年 | 3454篇 |
2014年 | 5107篇 |
2013年 | 7881篇 |
2012年 | 11390篇 |
2011年 | 12247篇 |
2010年 | 6840篇 |
2009年 | 6304篇 |
2008年 | 11536篇 |
2007年 | 12305篇 |
2006年 | 11803篇 |
2005年 | 12167篇 |
2004年 | 11561篇 |
2003年 | 11035篇 |
2002年 | 10647篇 |
2001年 | 1505篇 |
2000年 | 1130篇 |
1999年 | 1600篇 |
1998年 | 2332篇 |
1997年 | 2022篇 |
1996年 | 1702篇 |
1995年 | 1582篇 |
1994年 | 1423篇 |
1993年 | 1356篇 |
1992年 | 1042篇 |
1991年 | 955篇 |
1990年 | 836篇 |
1989年 | 823篇 |
1988年 | 843篇 |
1987年 | 723篇 |
1986年 | 842篇 |
1985年 | 909篇 |
1984年 | 1190篇 |
1983年 | 1142篇 |
1982年 | 1603篇 |
1981年 | 1479篇 |
1980年 | 1364篇 |
1979年 | 750篇 |
1978年 | 881篇 |
1977年 | 768篇 |
1976年 | 679篇 |
1975年 | 553篇 |
1974年 | 578篇 |
Objectives
Despite evidence for increased musculoskeletal injury after concussion recovery, there is a lack of dynamic balance assessments that could inform management and research into this increased injury risk post-concussion. Our purpose was to identify tandem gait dynamic balance deficits in recreational athletes with a concussion history within the past 18-months compared to matched controls.Design
Cross-sectional, laboratory study.Methods
Fifteen participants with a concussion history (age: 19.7 ± 0.9 years; 9 females; median time since concussion 126 days, range 28–432 days), and 15 matched controls (19.7 ± 1.6 years; 9 females) with no recent concussion history participated. We measured center-of-pressure (COP) outcomes (velocity, path length, speed, dual-task cost) under 4 tandem gait conditions: (1) tandem gait, (2) tandem gait, eyes closed, (3) tandem gait, eyes open, cognitive distraction, and (4) tandem gait, eyes closed, cognitive distraction.Results
The concussion history group demonstrated slower tandem gait velocity compared to the control group (4.0 cm/s difference), thus velocity was used as a covariate when analyzing COP path length and speed. The concussion history group (23.5%) demonstrated greater COP speed dual-task cost than the control group (16.3%) during the eyes closed dual-task condition. No other comparisons were statistically significant.Conclusions
There may be subtle dynamic balance differences during tandem gait that are detectable after return-to-activity following concussion, but the clinical significance of these findings is unclear. Longitudinal investigations should identify acute movement deficits in varying visual and cognitive scenarios after concussion in comparison with recovery on traditional concussion assessment tools while also recording musculoskeletal injury outcomes. 相似文献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Method: This systematic review evaluated nine studies which met inclusion criteria in terms of participants, intervention procedures, outcomes and certainty of evidence.
Results: Seven studies revealed a substantial reduction of aggressive behaviour or anger. Certainty of evidence was rated inconclusive in most cases due to absence of experimental control.
Conclusions: We can conclude that body-oriented PMT, involving progressive relaxation and meditation procedure “Soles of the Feet”, is a promising approach. However, the paucity of studies and methodological limitations preclude classifying it as an evidence-based practice. This suggests stronger methodological research and research aimed at PMT’s mechanisms of action (e.g., improved interoceptive awareness) is warranted. 相似文献