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   2575916篇
  免费   189194篇
  国内免费   7535篇
耳鼻咽喉   34261篇
儿科学   85139篇
妇产科学   71555篇
基础医学   362902篇
口腔科学   69585篇
临床医学   233528篇
内科学   512841篇
皮肤病学   62425篇
神经病学   213123篇
特种医学   99814篇
外国民族医学   736篇
外科学   385903篇
综合类   50300篇
现状与发展   5篇
一般理论   967篇
预防医学   195056篇
眼科学   56526篇
药学   187785篇
  8篇
中国医学   5332篇
肿瘤学   144854篇
  2021年   19911篇
  2019年   20616篇
  2018年   29273篇
  2017年   22590篇
  2016年   26220篇
  2015年   29505篇
  2014年   40442篇
  2013年   60426篇
  2012年   80223篇
  2011年   84486篇
  2010年   51003篇
  2009年   49148篇
  2008年   79036篇
  2007年   83838篇
  2006年   85568篇
  2005年   81737篇
  2004年   78728篇
  2003年   76055篇
  2002年   73336篇
  2001年   128408篇
  2000年   131333篇
  1999年   110506篇
  1998年   31254篇
  1997年   27923篇
  1996年   28221篇
  1995年   27383篇
  1994年   25064篇
  1993年   23289篇
  1992年   85061篇
  1991年   81544篇
  1990年   78738篇
  1989年   76003篇
  1988年   69408篇
  1987年   67953篇
  1986年   63504篇
  1985年   60472篇
  1984年   44886篇
  1983年   37849篇
  1982年   22370篇
  1981年   19905篇
  1979年   38890篇
  1978年   27371篇
  1977年   23164篇
  1976年   21420篇
  1975年   22758篇
  1974年   26738篇
  1973年   25330篇
  1972年   23734篇
  1971年   21933篇
  1970年   20157篇
排序方式: 共有10000条查询结果,搜索用时 312 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