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   3235056篇
  免费   253587篇
  国内免费   6254篇
耳鼻咽喉   48094篇
儿科学   99902篇
妇产科学   89024篇
基础医学   453185篇
口腔科学   96016篇
临床医学   289851篇
内科学   628080篇
皮肤病学   68672篇
神经病学   268563篇
特种医学   129050篇
外国民族医学   1251篇
外科学   493655篇
综合类   78125篇
现状与发展   7篇
一般理论   1307篇
预防医学   251652篇
眼科学   78027篇
药学   243802篇
  6篇
中国医学   6365篇
肿瘤学   170263篇
  2018年   31628篇
  2016年   27213篇
  2015年   30711篇
  2014年   44113篇
  2013年   67409篇
  2012年   89972篇
  2011年   95084篇
  2010年   56113篇
  2009年   54178篇
  2008年   90746篇
  2007年   97272篇
  2006年   98228篇
  2005年   95842篇
  2004年   92393篇
  2003年   89534篇
  2002年   88438篇
  2001年   149453篇
  2000年   154536篇
  1999年   131048篇
  1998年   37286篇
  1997年   33990篇
  1996年   33157篇
  1995年   32041篇
  1994年   30021篇
  1993年   27938篇
  1992年   104855篇
  1991年   101210篇
  1990年   98182篇
  1989年   95022篇
  1988年   88250篇
  1987年   87004篇
  1986年   82877篇
  1985年   79191篇
  1984年   59787篇
  1983年   50866篇
  1982年   30867篇
  1981年   27618篇
  1980年   25877篇
  1979年   56637篇
  1978年   40045篇
  1977年   34191篇
  1976年   31621篇
  1975年   34364篇
  1974年   41805篇
  1973年   40085篇
  1972年   37946篇
  1971年   35357篇
  1970年   33357篇
  1969年   31310篇
  1968年   28813篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
42.
43.

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   
44.
Academic output is just one aspect of a successful career as a plastic surgeon. However, for those with a strong interest in academia, the academic output of a department will likely be a key factor when deciding how to rank jobs. The aim of this study was to quantify and rank the academic output of plastic surgery units across the UK and Ireland. The Institute for Scientific Information (ISI) Web of Science Bibliometric analysis tool was used to collate cumulative (1950–2016), 10 year (2006–2016) and 3 years (2013–2015) research output data for plastic surgery units in the UK and Ireland. Sixty-six plastic surgery units were identified. Departments were ranked for each time period according to the number of papers produced, number of citations (Nc) and h-index (a measure of the impact of scientific output). The top 3 departments for number of papers in the last 10 years were The Royal Free Hospital, London (226) Broomfield Hospital, Chelmsford (218), and Morriston Hospital and Swansea (188). The top 3 for h-number were The Royal Free Hospital (21) Wythenshawe Hospital, Manchester (18) and Morriston Hospital (17). Academic output varies across plastic surgery units in the UK and Ireland. A number of departments have consistently maintained high academic outputs across the years and will be of interest to surgeons hoping to pursue a career in academia.  相似文献   
45.
46.
47.
48.
49.

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   
50.
School Mental Health - A dual approach to mental health in schools has been widely defended, where the assessment of psychological distress and the examination of strengths/well-being are two...  相似文献   
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