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   2579557篇
  免费   189379篇
  国内免费   7583篇
耳鼻咽喉   34310篇
儿科学   85261篇
妇产科学   71587篇
基础医学   363333篇
口腔科学   69643篇
临床医学   233736篇
内科学   514171篇
皮肤病学   62451篇
神经病学   213363篇
特种医学   99907篇
外国民族医学   736篇
外科学   386331篇
综合类   50319篇
现状与发展   5篇
一般理论   968篇
预防医学   195217篇
眼科学   56546篇
药学   188032篇
  8篇
中国医学   5363篇
肿瘤学   145232篇
  2021年   19980篇
  2019年   20690篇
  2018年   29347篇
  2017年   22641篇
  2016年   26304篇
  2015年   29593篇
  2014年   40567篇
  2013年   60546篇
  2012年   80429篇
  2011年   84707篇
  2010年   51124篇
  2009年   49245篇
  2008年   79163篇
  2007年   84012篇
  2006年   85698篇
  2005年   81900篇
  2004年   78896篇
  2003年   76205篇
  2002年   73472篇
  2001年   128483篇
  2000年   131406篇
  1999年   110586篇
  1998年   31298篇
  1997年   27956篇
  1996年   28243篇
  1995年   27417篇
  1994年   25094篇
  1993年   23440篇
  1992年   85112篇
  1991年   81595篇
  1990年   78796篇
  1989年   76076篇
  1988年   69457篇
  1987年   68006篇
  1986年   63535篇
  1985年   60517篇
  1984年   44924篇
  1983年   37870篇
  1982年   22382篇
  1981年   19912篇
  1979年   38914篇
  1978年   27381篇
  1977年   23170篇
  1976年   21423篇
  1975年   22771篇
  1974年   26745篇
  1973年   25345篇
  1972年   23744篇
  1971年   21941篇
  1970年   20170篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
53.

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.
55.
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.
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.

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.
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