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   22747篇
  免费   978篇
  国内免费   281篇
耳鼻咽喉   52篇
儿科学   617篇
妇产科学   107篇
基础医学   1994篇
口腔科学   29篇
临床医学   4059篇
内科学   6924篇
皮肤病学   30篇
神经病学   1292篇
特种医学   931篇
外科学   2537篇
综合类   2535篇
预防医学   546篇
眼科学   162篇
药学   1559篇
  8篇
中国医学   328篇
肿瘤学   296篇
  2023年   274篇
  2022年   492篇
  2021年   749篇
  2020年   706篇
  2019年   761篇
  2018年   791篇
  2017年   630篇
  2016年   533篇
  2015年   703篇
  2014年   1628篇
  2013年   1415篇
  2012年   1117篇
  2011年   1273篇
  2010年   1110篇
  2009年   1128篇
  2008年   1190篇
  2007年   1083篇
  2006年   1020篇
  2005年   822篇
  2004年   698篇
  2003年   584篇
  2002年   490篇
  2001年   395篇
  2000年   369篇
  1999年   334篇
  1998年   256篇
  1997年   261篇
  1996年   256篇
  1995年   227篇
  1994年   212篇
  1993年   198篇
  1992年   173篇
  1991年   172篇
  1990年   137篇
  1989年   107篇
  1988年   155篇
  1987年   106篇
  1986年   99篇
  1985年   149篇
  1984年   190篇
  1983年   104篇
  1982年   118篇
  1981年   107篇
  1980年   117篇
  1979年   81篇
  1978年   65篇
  1977年   73篇
  1976年   82篇
  1975年   72篇
  1974年   58篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
The purpose of this study is to show a very rare complication of acute cocaine poisoning, namely heart rupture. In the present case report, acute cocaine intoxication caused massive myocardial infarction, resulting in heart rupture and cardiac tamponade. A crime scene investigation found a dead body on the street in a drug dealing district. Examination of the body showed no external injuries. A thorough autopsy was performed showing massive cardiac tamponade with 510 ml of blood within the pericardium and full-thickness tissue lesion at the posterior wall of the left ventricle of 3.5 × 3 cm. Histological examination in hematoxylin and eosin was performed and confirmed the interruption of the posterior wall of the left ventricle with the presence of blood. In fact, although the correlation between cocaine and myocardial damage is well established, the relationship between heart rupture and acute cocaine intoxication is an extremely rare event. Moreover, since there are, to date, few reports of similar deaths, our report provides useful information regarding sudden death in a cocaine abuser. It is, therefore, of crucial importance to report this case to the scientific community.  相似文献   
6.
Aim of the studyOur study aimed to identify the characteristics of cardiac involvement in eosinophilic granulomatosis with polyangiitis (EGPA).MethodsWe conducted a retrospective analytic study including EGPA cases diagnosed between 2000 and 2019 in an internal medicine department. Diagnosis was made according to the 1990 American College of Rheumatology criteria and the 2012 Chapel Hill Concensus.ResultsEleven EGPA cases were included, 64% of patients were female. Median age at diagnosis was 52 years [42–58]. Heart damage revealed EGPA in 55% of cases with a significant predominance of women (p = 0.015). The main cardiac manifestations were myocarditis, ischemic cardiomyopathy due to small vessel vasculitis, cardiac tamponade and intracardiac thrombus. Cardiac magnetic resonance imaging (MRI) mainly showed subendocardial hyposignal in early infusion and late enhancement in the same areas, nodular by locations, associated with impaired left ventricle function and micro-infarctions by distal vasculitis. Cardiac damage was associated to ANCA negativity in 83.3% of cases. The median Birmingham Vasculitis Activity Score version3 (BVAS v3) was 16 [10–17]. Under conventional treatment, no relapses had occurred. The median vasculitis damage index (VDI) was 2 [1–2.3] and the mortality rate was zero after a mean follow-up of 43 months.ConclusionCardiomyopathy is a frequent revealing mode of EGPA. A late onset asthma and hypereosinophilia should guide the diagnosis. As ANCA research often turns out to be negative, histological evidence is recommended in this context. The contribution of cardiac MRI in the diagnosis of EGPA remains to be defined.  相似文献   
7.
8.
A 25-year-old, emaciated man without medical treatment was found to have died suddenly at home by his mother. At autopsy, there were no injuries to his body, but significant circulatory insufficiency was observed. Electron microscopy revealed abnormal mitochondria in cells of the cardiac conduction system. The conduction system was filled with mitochondrial size abnormalities and mitochondrial cristae abnormalities. No notable abnormal findings were observed in other organs. Genetic examination of the blood revealed the mitochondrial pathogenetic variant m.3243A>G. Epileptic seizures, diabetic ketoacidosis, and hyperosmolar hyperglycemic state were unlikely to be the cause of sudden death. The cause of death was diagnosed as arrhythmia possibly induced by the failure of the cardiac conduction system due to mitochondrial disease. This is a rare case of sudden death caused by an accumulation of abnormal mitochondria in the cardiac conduction system.  相似文献   
9.
10.
Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive.  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