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   97085篇
  免费   7285篇
  国内免费   4978篇
耳鼻咽喉   301篇
儿科学   1417篇
妇产科学   476篇
基础医学   6072篇
口腔科学   647篇
临床医学   14539篇
内科学   17404篇
皮肤病学   303篇
神经病学   7702篇
特种医学   5872篇
外国民族医学   2篇
外科学   15154篇
综合类   19447篇
现状与发展   5篇
一般理论   1篇
预防医学   4514篇
眼科学   944篇
药学   9119篇
  62篇
中国医学   4736篇
肿瘤学   631篇
  2024年   304篇
  2023年   1555篇
  2022年   2866篇
  2021年   4102篇
  2020年   3762篇
  2019年   3056篇
  2018年   3077篇
  2017年   3279篇
  2016年   3464篇
  2015年   3353篇
  2014年   6273篇
  2013年   7268篇
  2012年   5746篇
  2011年   6403篇
  2010年   5381篇
  2009年   5048篇
  2008年   5111篇
  2007年   5154篇
  2006年   4873篇
  2005年   4217篇
  2004年   3402篇
  2003年   3029篇
  2002年   2567篇
  2001年   2392篇
  2000年   1989篇
  1999年   1651篇
  1998年   1453篇
  1997年   1344篇
  1996年   1058篇
  1995年   933篇
  1994年   796篇
  1993年   633篇
  1992年   523篇
  1991年   443篇
  1990年   391篇
  1989年   328篇
  1988年   297篇
  1987年   277篇
  1986年   236篇
  1985年   290篇
  1984年   223篇
  1983年   132篇
  1982年   147篇
  1981年   141篇
  1980年   107篇
  1979年   73篇
  1978年   52篇
  1977年   48篇
  1976年   37篇
  1975年   19篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.  相似文献   
4.
5.
6.
7.
8.
BackgroundCoronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%).MethodsWe analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively.ResultsIn 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]).ConclusionsHeart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization.  相似文献   
9.
Objective: To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases. Methods: In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks. Results: In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values. Conclusions: The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.  相似文献   
10.
目的探讨经皮冠状动脉介入(PCI)和静脉溶栓在急性心肌梗死患者中的应用价值。方法选择我院2013年1月至2014年9月收治的60例急性心肌梗死患者作为研究对象,随机分为实验组和对照组各30例。实验组患者采用PCI治疗,对照组患者采用静脉溶栓治疗,比较两组患者血管再通率、死亡发生率、ST段回落情况、住院时间、近远期不良事件发生率、左室舒张末径和左室射血分数变化情况。结果实验组血管再通率显著高于对照组,差异有统计学意义(P<0.05),而近期和远期不良事件发生率均低于对照组,近期不良事件发生率组间比较差异有统计学意义(P<0.05),而远期不良事件发生率比较差异无统计学意义(P>0.05)。实验组患者死亡发生率、ST段回落和住院时间均低于对照组,差异均有统计学意义(P<0.05)。实验组左室射血分数在术后1个月、3个月和6个月时均显著高于对照组,差异均有统计学意义(P<0.05)。结论急性心肌梗死患者应用PCI治疗可显著提高血管再通率、降低死亡和不良事件发生率,有效改善心功能。  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