全文获取类型
| 收费全文 | 2573016篇 |
| 免费 | 189199篇 |
| 国内免费 | 7526篇 |
学科分类
| 医药卫生 | 2769741篇 |
出版年
| 2019年 | 20624篇 |
| 2018年 | 29281篇 |
| 2017年 | 22594篇 |
| 2016年 | 26227篇 |
| 2015年 | 29505篇 |
| 2014年 | 40443篇 |
| 2013年 | 60432篇 |
| 2012年 | 80237篇 |
| 2011年 | 84503篇 |
| 2010年 | 51012篇 |
| 2009年 | 49144篇 |
| 2008年 | 79021篇 |
| 2007年 | 83847篇 |
| 2006年 | 85575篇 |
| 2005年 | 81741篇 |
| 2004年 | 78731篇 |
| 2003年 | 76054篇 |
| 2002年 | 73357篇 |
| 2001年 | 128422篇 |
| 2000年 | 131341篇 |
| 1999年 | 110508篇 |
| 1998年 | 31254篇 |
| 1997年 | 27823篇 |
| 1996年 | 26434篇 |
| 1995年 | 27229篇 |
| 1994年 | 24934篇 |
| 1993年 | 23290篇 |
| 1992年 | 85062篇 |
| 1991年 | 81546篇 |
| 1990年 | 78740篇 |
| 1989年 | 76011篇 |
| 1988年 | 69411篇 |
| 1987年 | 67956篇 |
| 1986年 | 63504篇 |
| 1985年 | 60473篇 |
| 1984年 | 44889篇 |
| 1983年 | 37849篇 |
| 1982年 | 22372篇 |
| 1981年 | 19907篇 |
| 1979年 | 38892篇 |
| 1978年 | 27372篇 |
| 1977年 | 23170篇 |
| 1976年 | 21419篇 |
| 1975年 | 22758篇 |
| 1974年 | 26741篇 |
| 1973年 | 25334篇 |
| 1972年 | 23733篇 |
| 1971年 | 21933篇 |
| 1970年 | 20158篇 |
| 1969年 | 19417篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
51.
52.
53.
Robert C. Lynall J. Troy Blackburn Kevin M. Guskiewicz Stephen W. Marshall Prudence Plummer Jason P. Mihalik 《Journal of Science and Medicine in Sport》2019,22(5):503-508
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54.
Samir Gupta MD MDCS AGAF Balambal Bharti MBBS MPH PhD Dennis J. Ahnen MD Daniel D. Buchanan PhD Iona C. Cheng PhD MPH Michelle Cotterchio PhD Jane C. Figueiredo PhD Steven J. Gallinger MD MSc Robert W. Haile DrPH MPH Mark A. Jenkins PhD Noralane M. Lindor MD Finlay A. Macrae MD AGAF Loïc Le Marchand MD PhD Polly A. Newcomb PhD MPH Stephen N. Thibodeau PhD Aung Ko Win MBBS MPH PhD Maria Elena Martinez PhD 《Cancer》2020,126(13):3013-3020
55.
Key Jana Maletzko Antonia Kohli Aneesha Gispert Suzana Torres-Odio Sylvia Wittig Ilka Heidler Juliana Bárcena Clea López-Otín Carlos Lei Yuanjiu West A. Phillip Münch Christian Auburger Georg 《Neurogenetics》2020,21(3):187-203
neurogenetics - Human RNF213, which encodes the protein mysterin, is a known susceptibility gene for moyamoya disease (MMD), a cerebrovascular condition with occlusive lesions and compensatory... 相似文献
56.
57.
58.
Stepanova E. S. Makarenkova L. M. Chistyakov V. V. Rybakov Yu. L. Gukasov V. M. Fedotcheva T. A. Parshin V. A. Votyakov V. A. Shimanovskii N. L. 《Pharmaceutical Chemistry Journal》2019,52(12):1016-1020
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was... 相似文献
59.
M.F. Werner A. López-Rueda F.X. Zarco J. Blasco L. San Román S. Amaro E. Carrero R. Valero L. Oleaga J.M. Macho N. Bargalló 《Radiologia》2019,61(2):143-152
Purpose
Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.Methods
Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.Results
CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.Conclusion
PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO. 相似文献60.
