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   30708篇
  免费   2066篇
  国内免费   556篇
耳鼻咽喉   69篇
儿科学   743篇
妇产科学   63篇
基础医学   1045篇
口腔科学   226篇
临床医学   6909篇
内科学   13709篇
皮肤病学   19篇
神经病学   546篇
特种医学   903篇
外科学   2648篇
综合类   3840篇
现状与发展   1篇
一般理论   2篇
预防医学   406篇
眼科学   56篇
药学   1513篇
  11篇
中国医学   509篇
肿瘤学   112篇
  2024年   23篇
  2023年   506篇
  2022年   638篇
  2021年   1184篇
  2020年   1167篇
  2019年   1275篇
  2018年   1160篇
  2017年   745篇
  2016年   661篇
  2015年   827篇
  2014年   1961篇
  2013年   1712篇
  2012年   1262篇
  2011年   1510篇
  2010年   1287篇
  2009年   1244篇
  2008年   1438篇
  2007年   1465篇
  2006年   1286篇
  2005年   1253篇
  2004年   984篇
  2003年   938篇
  2002年   787篇
  2001年   795篇
  2000年   676篇
  1999年   685篇
  1998年   605篇
  1997年   602篇
  1996年   492篇
  1995年   416篇
  1994年   430篇
  1993年   343篇
  1992年   382篇
  1991年   323篇
  1990年   322篇
  1989年   235篇
  1988年   248篇
  1987年   206篇
  1986年   211篇
  1985年   192篇
  1984年   204篇
  1983年   163篇
  1982年   127篇
  1981年   93篇
  1980年   73篇
  1979年   66篇
  1978年   49篇
  1977年   18篇
  1976年   21篇
  1973年   16篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
21.
22.
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.  相似文献   
23.
The Impella 5.0, a percutaneously inserted left ventricular assist device, has been used to support patients who have severe heart failure or who are undergoing high-risk percutaneous coronary intervention. We report our surgical placement of the Impella 5.0, through a graft sewn to the aorta, to unload the left ventricle of a 59-year-old man who was undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy shock. The patient underwent successful placement of a long-term left ventricular assist device before his discharge from the hospital. The versatility of the Impella 5.0 is exemplified in this patient who was successfully bridged to long-term support.  相似文献   
24.
25.
目的:评估八段锦干预心力衰竭的疗效及安全性。方法:搜索中国知网数据库、中国生物医学文献数据库、万方数据库以及维普中文全文数据库;PubMed、Cochrane Library、web of science、EMBASE。检索时间为建库至2019年2月28日。对纳入的随机对照试验(RCT)用Cochrane手册进行偏倚风险评估,用Rev Man 5.3软件进行Meta分析。结果:纳入6篇文献,7个随机对照研究,共计543例心力衰竭患者。与对照组比较,观察组MLHFQ减少[MD=10.88,95%CI=(8.22,13.54)],6分钟步行试验(6MWT)提高[MD=107.81,95%CI=(75.83,139.78)],左心室射血分数(LVEF)提高[MD=3.62,95%CI=(2.04,5.19)],B型利钠肽(BNP)降低[MD=73.32,95%CI=(45.12,101.53)],临床疗效[OR=4.00,95%CI=(1.35,11.83)],中医证候评分[OR=4.57,95%CI=(2.03,10.31)]。结论:八段锦可改善心力衰竭患者的心功能,用于稳定期的康复治疗。  相似文献   
26.
27.
Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm2) was underestimated by the standard method (1.05 ± 0.47 cm2; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index.  相似文献   
28.
29.
A 20‐year‐old Congolese woman presented with presyncope, dyspnea, and anasarca. Past medical history was unremarkable. Echocardiography revealed a rare combination of giant right atrium (RA), a dilated and hypertrophied right ventricle, subvalvular pulmonary stenosis (subPS), severe tricuspid regurgitation (TR), pericardial effusion and what appeared to be a spontaneously closed ventricular septal defect (VSD). Cardiac Magnetic Resonance and Cardiac Computed Tomography confirmed the findings excluding the presence of intra‐cardiac and extra‐cardiac shunt and other associated congenital anomalies. The patient underwent subPS resection, right atrioplasty, and tricuspid annuloplasty. Multimodality approach facilitated the detection of the abnormalities and provided clarity when determining the optimal surgical strategy.  相似文献   
30.
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