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   422篇
  免费   41篇
  国内免费   2篇
耳鼻咽喉   7篇
儿科学   9篇
妇产科学   9篇
基础医学   60篇
口腔科学   5篇
临床医学   65篇
内科学   124篇
皮肤病学   4篇
神经病学   52篇
特种医学   13篇
外科学   34篇
综合类   6篇
预防医学   9篇
眼科学   21篇
药学   11篇
肿瘤学   36篇
  2023年   5篇
  2022年   7篇
  2021年   15篇
  2020年   3篇
  2019年   16篇
  2018年   16篇
  2017年   11篇
  2016年   11篇
  2015年   11篇
  2014年   19篇
  2013年   16篇
  2012年   28篇
  2011年   25篇
  2010年   20篇
  2009年   16篇
  2008年   29篇
  2007年   35篇
  2006年   35篇
  2005年   27篇
  2004年   24篇
  2003年   17篇
  2002年   23篇
  2001年   7篇
  2000年   4篇
  1998年   3篇
  1997年   1篇
  1995年   1篇
  1993年   1篇
  1992年   7篇
  1991年   4篇
  1990年   5篇
  1989年   1篇
  1988年   1篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   2篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1976年   3篇
  1974年   2篇
  1973年   1篇
  1969年   2篇
  1965年   1篇
排序方式: 共有465条查询结果,搜索用时 444 毫秒
51.

Background  

Mycoplasma pneumoniae is responsible for more than 20% of community acquired pneumonia cases, and capable of causing upper respiratory illness as well. Complications of M.pneumoniae infections include CNS involvement but other as pericarditis were also reported. The lack of feasible culture methods and under appreciation of the pathogens ability to cause invasive disease leads to reduced number of diagnosed M.pneumoniae related complications. In contrast to many other respiratory pathogens causing pneumonia, M. pneumoniae related severe pleural complications were almost never reported.  相似文献   
52.
53.
54.
55.
56.
57.
Different studies have yielded conflicting results regarding the association of hypertensive response to exercise and cardiovascular morbidity. We compared two different definitions of exaggerated hypertensive response to exercise and their association with cardio-respiratory fitness in a population of healthy firefighters. We examined blood pressure response to exercise in 720 normotensive male career firefighters. Fitness was measured as peak metabolic equivalent tasks (METs) achieved during maximal exercise treadmill tests. Abnormal hypertensive response was defined either as systolic blood pressure ≥ 200 mm Hg; or alternatively, as responses falling in the upper tertile of blood pressure change from rest to exertion, divided by the maximal workload achieved. Using the simple definition of a 200 mm Hg cutoff at peak exercise less fit individuals (METs ≤12) were protected from an exaggerated hypertensive response (OR 0.45, 95%CI 0.30–0.67). However, using the definition of exercise-induced hypertension that corrects for maximal workload, less fit firefighters had almost twice the risk (OR 1.8, 95%CI 1.3–2.47). Blood pressure change corrected for maximal workload is better correlated with cardiorespiratory fitness. Systolic blood pressure elevation during peak exercise likely represents an adaptive response, whereas elevation out of proportion to the maximal workload may indicate insufficient vasodilation and a maladaptive response. Prospective studies are needed to best define exaggerated blood pressure response to exercise.  相似文献   
58.
59.
Cyclosporin, a potent new immunosuppressive agent, was used (alone or in combination with other drugs) in 28 canine single lung allograft recipients. Mean recipient survival with good allograft function was 155 days with cyclosporin and far exceeded that obtained in previous single lung allograft recipients treated with standard immunosuppression (15 to 22 days). The results of these experiments were as follows: (1) 20% of the recipient animals exhibited no evidence of rejection whatsoever; (2) four of 28 animals survived more than 350 days with good allograft function; (3) 79% of the animals exhibited some evidence of rejection that was easily reversed in 74% of instances with corticosteroids; (4) 10 of 28 animals exhibited good lung allograft function 5 months or more after operation; (5) in cyclosporin-treated lung allograft recipients, rejection was diagnosed by the presence of infiltrate on chest roentgenogram, analysis of the cellular content of bronchoalveolar lavage samples, and decreased perfusion on 99mtechnetium lung scan; (6) complete healing without stenosis of the bronchial anastomosis occurred in 82% of the animals studied. One of two patients treated with cyclosporin after undergoing single lung allografting survived 7 weeks after transplantation and 4 weeks after contralateral pneumonectomy. Episodes of rejection were reversible, and the bronchial anastomosis healed normally. This overall experience indicates that cyclosporin, although not a perfect immunosuppressive agent, increases the likelihood of success with therapeutic single lung transplantation.  相似文献   
60.
BACKGROUND: Pseudophakic children tend to develop a large myopic shift. This may be in part due to accelerated growth in axial length. The purpose of this study was to evaluate and compare the postoperative change in axial length (DeltaAL) in pseudophakic eyes, after extraction of traumatic or congenital cataract. METHODS: Included in this retrospective study were 20 children who had undergone surgery for traumatic, unilateral congenital, or bilateral congenital cataracts. All patients were under 10 years old at the time of operation. Axial length was measured perioperatively as well as 1 year or more postoperatively. The three groups were subdivided according to patients' ages (below or above 5 years). The DeltaAL in the operated eyes was compared with DeltaAL of the fellow nonoperated eyes. The difference in DeltaAL between operated and fellow nonoperated eyes was compared among the groups. RESULTS: DeltaAL was greater for operated eyes than for fellow nonoperated eyes (traumatic cataract: p=0.06; unilateral congenital cataract, p=0.055). Axial elongation was significantly greater in children under 5 years old at operation than in those older than 5 (p=0.025). The difference in rate of DeltaAL between operated and fellow nonoperated eyes, per 1 year of follow-up, was similar for traumatic and unilateral congenital cataract groups. CONCLUSIONS: This study demonstrated a tendency toward greater axial lengthening in pseudophakic eyes of children, when compared with their nonoperated eyes. No significant difference was found in the tendency for increased axial lengthening between eyes operated on for traumatic cataracts and those operated on for congenital cataracts.  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