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   513篇
  免费   39篇
  国内免费   3篇
耳鼻咽喉   1篇
儿科学   10篇
妇产科学   2篇
基础医学   75篇
口腔科学   6篇
临床医学   29篇
内科学   98篇
皮肤病学   12篇
神经病学   170篇
特种医学   16篇
外科学   28篇
综合类   3篇
一般理论   1篇
预防医学   25篇
眼科学   28篇
药学   37篇
中国医学   5篇
肿瘤学   9篇
  2021年   8篇
  2018年   7篇
  2017年   8篇
  2016年   9篇
  2015年   7篇
  2014年   10篇
  2013年   11篇
  2012年   10篇
  2011年   17篇
  2010年   11篇
  2009年   15篇
  2008年   14篇
  2007年   25篇
  2006年   21篇
  2005年   20篇
  2004年   21篇
  2003年   20篇
  2002年   25篇
  2001年   15篇
  2000年   10篇
  1999年   12篇
  1998年   9篇
  1997年   13篇
  1996年   8篇
  1995年   5篇
  1992年   8篇
  1991年   10篇
  1988年   9篇
  1987年   12篇
  1986年   8篇
  1985年   12篇
  1984年   5篇
  1983年   8篇
  1982年   4篇
  1981年   5篇
  1979年   4篇
  1976年   10篇
  1975年   5篇
  1973年   6篇
  1972年   4篇
  1970年   4篇
  1967年   5篇
  1966年   6篇
  1942年   5篇
  1941年   5篇
  1940年   4篇
  1938年   5篇
  1928年   4篇
  1927年   4篇
  1923年   7篇
排序方式: 共有555条查询结果,搜索用时 15 毫秒
11.
Why laparoscopic cholecystectomy today?   总被引:1,自引:0,他引:1  
Traditional open cholecystectomy became the gold standard of surgical treatment for symptomatic gallstone disease during the last century. In spite of its good results, clinicians have been trying to establish effective nonsurgical methods of eliminating gallstones. Although oral, percutaneous, or retrograde litholysis can be used effectively for cholesterol stones, these represent only 10% of all gallstones. Moreover, intracorporeal lithotripsy is an invasive method, and while extracorporeal shock wave lithotripsy is a promising procedure, even after careful selection, only 70%–80% of the patients become stone-free within 1 year. In fact, none of the methods which leave the gallbladder intact are free of complications, and they are followed by 50% stone recurrence within 5 years. Since 1987, laparoscopic cholecystectomy has become the procedure of choice as it is safe and only minimally invasive. We believe that the laparoscopic technique is a promising way to the surgery of the future.  相似文献   
12.
BACKGROUND: The spinal administration of some N-methyl-d-aspartate receptor antagonists results in antinociception and potentiates the effects of opioids and alpha2-adrenoceptor agonists, but ketamine and its enantiomers have not been examined. The present study investigated the interactions of racemic ketamine, R(-)-ketamine and S(+)-ketamine with morphine and with dexmedetomidine. METHODS: Intrathecal catheters were implanted into male Wistar rats. Three days later, the acute nociceptive sensitivity was assessed using the tail-flick test. Analgesic latencies were converted to the percentage maximum possible effect. The dose that yielded 50% of the maximum possible effect (ED50) and dose-response and time-course curves were determined for the ketamines (30-300 microg), morphine (0.1-3.0 microg), dexmedetomidine (0.3-10.0 microg), and mixtures of two doses of ketamines (30 or 100 microg) with different doses of morphine or dexmedetomidine for fixed-dose analysis. RESULTS: Neither racemic ketamine nor its enantiomers alone had a significant effect on the tail-flick test, with the exception of the highest dose of racemic ketamine, which caused motor impairment. Morphine and dexmedetomidine each produced dose-dependent antinociception, with ED50 of 1.7 microg (95% confidence interval: 1.04-2.32) and 4. 85 microg (3.96-5.79), respectively. A low dose (30 microg) of racemic ketamine or its enantiomers did not influence the ED50 of morphine significantly. Coadministration of 100 microg racemic ketamine or S(+)-ketamine, but not R(-)-ketamine, significantly enhanced and prolonged the antinociceptive effect of morphine. Both doses of racemic ketamine or its isomers significantly decreased the ED50 value for dexmedetomidine, although the higher dose of racemic or S(+)-ketamine had the highest potency. One-hundred micrograms of racemic ketamine or S(+)-ketamine also prolonged the effects of dexmedetomidine. CONCLUSIONS: These data indicate that racemic ketamine and S(+)-ketamine, but not R(-)-ketamine, exhibit similar effectiveness in potentiating the antinociceptive effects of both morphine and dexmedetomidine.  相似文献   
13.
14.
Ohne ZusammenfassungAusgeführt zum Teil mit der Unterstützung der FürstPaul Esterh'azyschen Stiftung für wissenschaftliche Forschung.  相似文献   
15.
Introduction:Multimodality assessment of coronary artery lesions has demonstrated superior effectiveness compared to the conventional approach, for assessing both anatomical and functional significance of a coronary stenosis. Multiple imaging modalities can be integrated into a fusion imaging tool to better assess myocardial ischemia.Material and methods:The FUSE-HEART trial is a single center, prospective, cohort study that will assess the impact of a coronary artery stenosis on myocardial function and viability, based on advanced fusion imaging technics derived from Cardiac Computed Tomography Angiography (CCTA). Moreover, the study will investigate the correlation between morphology and composition of the coronary plaques and myocardial ischemia in the territory irrigated by the same coronary artery. At the same time, imaging parameters will be correlated with inflammatory status of the subjects. The trial will include 100 subjects with coronary lesions found on CCTA examination. The study population will be divided into 2 groups: first group will consist of subjects with anatomically significant coronary lesions on native coronary arteries and the second one will include subjects surviving an acute myocardial infarction. The vulnerability score of the subjects will be calculated based on presence of CCTA vulnerability markers of the coronary plaques: napkin ring sign, positive remodeling, spotty calcifications, necrotic core, and low-density plaques. 3D fusion images of the coronary tree will be generated, integrating the images reflecting wall motion with the ones of coronary circulation. The fusion models will establish the correspondence between plaque composition and wall motion in the subtended myocardium of the coronary artery. The study primary outcome will be represented by the rate of major adverse cardiac events related to myocardial ischemia at 1-year post assessment, in correlation with the degree of coronary artery stenosis and myocardial ischemia or viability.The secondary outcomes are represented by the rate of re-hospitalization, rate of survival and rate of major adverse cardiovascular events (including cardiovascular death or stroke), in correlation with the morphology and composition of atheromatous plaques located in a coronary artery, and myocardial ischemia in the territory irrigated by the same coronary artery.Conclusion:In conclusion, FUSE-HEART will be a study based on modern imaging tools that will investigate the impact of a coronary artery stenosis on myocardial function and viability, using advanced fusion imaging technics derived from CCTA, sighting to validate plaque composition and morphology, together with inflammatory biomarkers, as predictors to myocardial viability.  相似文献   
16.
17.
18.
19.
目的:肺癌分期与肿瘤直径的关系已被证实是一个预后指标,因此被纳入1986年肺癌分类的国际系统。近年来由于CT飞速发展,人们可以诊断出更小的肺癌,于是有人提倡对肺癌Ⅰ期进一步分期,即根据肿瘤直径小于还是大于30mm,将无确切远处淋巴结转移的病例(Ⅰ期病例)细分为Ⅰa和Ⅰb期。在诊断无症状(即潜伏)的肺癌时,CT普查的开展使人们考虑肿瘤大小的预后价值。在此我们对CT普查诊断的无症状潜伏型肺癌作了分期与大小关系的报道。  相似文献   
20.
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