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   19363篇
  免费   1086篇
  国内免费   100篇
耳鼻咽喉   133篇
儿科学   377篇
妇产科学   343篇
基础医学   3194篇
口腔科学   457篇
临床医学   1604篇
内科学   3587篇
皮肤病学   723篇
神经病学   2057篇
特种医学   1289篇
外科学   2476篇
综合类   91篇
一般理论   7篇
预防医学   852篇
眼科学   321篇
药学   1804篇
中国医学   31篇
肿瘤学   1203篇
  2023年   71篇
  2022年   137篇
  2021年   241篇
  2020年   207篇
  2019年   249篇
  2018年   278篇
  2017年   270篇
  2016年   339篇
  2015年   436篇
  2014年   522篇
  2013年   681篇
  2012年   1023篇
  2011年   1172篇
  2010年   726篇
  2009年   730篇
  2008年   1173篇
  2007年   1260篇
  2006年   1233篇
  2005年   1212篇
  2004年   1173篇
  2003年   1216篇
  2002年   1170篇
  2001年   283篇
  2000年   218篇
  1999年   290篇
  1998年   313篇
  1997年   279篇
  1996年   232篇
  1995年   208篇
  1994年   179篇
  1993年   185篇
  1992年   148篇
  1991年   133篇
  1990年   135篇
  1989年   130篇
  1988年   143篇
  1987年   106篇
  1986年   91篇
  1985年   100篇
  1984年   113篇
  1983年   102篇
  1982年   104篇
  1981年   103篇
  1980年   108篇
  1979年   68篇
  1978年   68篇
  1977年   90篇
  1976年   66篇
  1975年   69篇
  1974年   75篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
41.
42.
BACKGROUND: Basal cell carcinoma shows a wide spectrum of clinical and histologic appearances. A distinct tumor variant with follicular infundibulocystic differentiation is recognized, and there are only a few reports on its clinical presentation and management. OBJECTIVE: To report a case of multiple infundibulocystic basal cell carcinomas with a unique unilateral presentation. METHODS: A clinical history was obtained. Photographs were taken, and punch biopsies were performed. RESULTS: An 83-year-old Caucasian female presented with multiple unilateral, asymptomatic, skin-colored, dome-shaped papules around the right mouth for 11 years without apparent change. Punch biopsies revealed findings typical of infundibulocystic basal cell carcinoma. CONCLUSIONS: A patient with clinically indolent multiple unilateral infundibulocystic basal cell carcinomas is described. Given the location of these multiple lesions, standard treatment modalities for basal cell carcinomas would have significant cosmetic and functional implications. A management approach with clinical follow-up and surgical intervention only for changing lesions is discussed.  相似文献   
43.
BACKGROUND: For the first time, microdialysis was used to investigate in vivo and online the myocardial metabolism during and after cardiac surgery in patients treated with two different methods of myocardial protection. METHODS: Thirty patients underwent standard CABG with one of two different methods of myocardial protection. The patients were randomised to receive either cold blood (COLD group) or warm modified Calafiore cardioplegia (WARM group). Microdialysis probes were implanted into the myocardium of left ventricular apical region of the heart. Cardioplegia was given antegrade only. Microdialysis measurements were performed at time intervals before, during and 24 h after cardiopulmonary bypass and analysed for glucose, lactate, pyruvate and glycerol. RESULTS: Myocardial lactate concentrations were significantly higher in the WARM group compared with that of the COLD group, while serum lactate was comparable. Glycerol was significantly higher at the end of the clamping time in the WARM group. At the same time the glucose-lactate ratio as a marker of nutritional disorder had significantly lower levels in the WARM group. The cumulative CK-MB release over 24 h was significantly higher in those hearts protected with warm blood. CONCLUSIONS: The oxidative stress measured was significantly higher in patients undergoing CABG using modified Calafiore cardioplegia, whereas the cold cardioplegia minimised the effects of aortic clamping. The results indicate that cold cardioplegia offers superior protection of the heart, in terms of more rapid normalisation of myocardial metabolism. In elective myocardial revascularisation, intermittent antegrade warm blood cardioplegia is a comparable safe method of myocardial protection. However, in patients referring to a long clamping time, advantages of cold cardioplegia for myocardial revascularisation may be magnified.  相似文献   
44.
45.
A 66-year-old man presented with bilateral subclavian steal syndrome (SSS) due to proximal subclavian artery occlusions. He was treated by percutaneous transluminal balloon angioplasty (PTA) and stent implantation in the left subclavian artery and by PTA alone in the right subclavian artery. We could demonstrate that interventional treatment of symptomatic bilateral SSS is possible. If PTA alone is insufficient, stent implantation should be considered.  相似文献   
46.
JC virus (JCV) infection is regularly asymptomatic in healthy individuals. In contrast, in immunocompromised individuals, highly activated virus replication may lead to PML. Peripheral blood cells (PBCs) are found to habor JCV DNA in healthy and diseased individuals and it is discussed that they might be responsible for dissemination of the virus to the central nervous system (CNS) during persistence. To better understand the role of JCV DNA in PBCs for persistent infection and pathogenesis, the authors characterized the extent of JCV infection in Ficoll-gradient purified blood cells (peripheral blood mononuclear cells [PBMCs]) of healthy and human immunodeficiency virus type 1 (HIV-1)-infected individuals. Virus activation in PBMCs from healthy JCV-infected individuals was found at a rate of 0% to 38% at low polymerase chain reaction (PCR) sensitivity. In progressive multifocal leukoencephalopathy (PML) patients, a stronger signal was found, indicating increased virus activation. JCV DNA was regularly detected in T and B lymphocytes and in monocytes at low levels. However, granulocytes were shown to be the predominant reservoir of JCV DNA harboring high copy numbers. Although the overall distribution of viral genomes holds true for the population studied, in the individual, a markedly changed pattern of distribution can be found.  相似文献   
47.
48.
49.
On the basis of two case discussions the authors deal with the clinical significance of the gastric diverticula. In one case a traction diverticulum near to the cardia was found with simultaneously existing intramural leiomyoma of the wall of the stomach. In a second case a typical congenital diverticulum near to the cardia was concerned. It is referred to diagnostic possibilities, differential diagnostic questions and therapy.  相似文献   
50.
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