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   5775篇
  免费   255篇
  国内免费   22篇
耳鼻咽喉   41篇
儿科学   246篇
妇产科学   77篇
基础医学   538篇
口腔科学   106篇
临床医学   427篇
内科学   1245篇
皮肤病学   179篇
神经病学   426篇
特种医学   170篇
外科学   1013篇
综合类   109篇
预防医学   242篇
眼科学   286篇
药学   501篇
  1篇
中国医学   38篇
肿瘤学   407篇
  2024年   2篇
  2023年   37篇
  2022年   120篇
  2021年   210篇
  2020年   108篇
  2019年   141篇
  2018年   166篇
  2017年   120篇
  2016年   173篇
  2015年   192篇
  2014年   276篇
  2013年   372篇
  2012年   538篇
  2011年   527篇
  2010年   285篇
  2009年   247篇
  2008年   388篇
  2007年   409篇
  2006年   373篇
  2005年   320篇
  2004年   319篇
  2003年   231篇
  2002年   183篇
  2001年   40篇
  2000年   34篇
  1999年   31篇
  1998年   25篇
  1997年   29篇
  1996年   19篇
  1995年   19篇
  1994年   17篇
  1993年   18篇
  1992年   6篇
  1991年   7篇
  1990年   13篇
  1989年   13篇
  1988年   6篇
  1987年   8篇
  1985年   8篇
  1984年   2篇
  1982年   3篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1975年   1篇
  1973年   1篇
  1972年   1篇
  1971年   2篇
  1970年   2篇
  1960年   1篇
排序方式: 共有6052条查询结果,搜索用时 0 毫秒
1.
Placement of tunnelled dialysis lines is effective using ultrasoundand fluoroscopic guidance [1] and has a higher success ratethan ‘blind’ insertion [2]. After the ultrasound guided access into a neck vein, wires andcatheters are guided in to a suitable position in the  相似文献   
2.
Liposarcomas are extremely rare in the mediastinum. They may achieve considerable size before causing any symptoms. Mediastinal liposarcomas may invade surrounding structures like the pericardium or the superior vena cava. Complete surgical excision is the optimal treatment in resectable cases. Excision of adjacent structures like the pericardium may be needed if the tumor infiltrates them. We report on a case of a giant liposarcoma of the mediastinum involving both hemithoraces and extending into the neck, which was successfully managed by complete surgical excision.  相似文献   
3.
Malignancy larynx usually presents early, the common symptoms being hoarseness, pain thorat, cough and irritation of throat. An advanced malignancy is likely to be complicated by a pharyngo-cutaneous fistula. However it is an occurrence towards the end stage of the disease. Here we present a case of malignancy larynx primarily presenting as pharyngo-cutaneous fistula without any other symptoms.  相似文献   
4.
5.
Abstract   Dissection of the pulmonary autograft is an extremely rare complication requiring emergent treatment as there is a chance of rupture and proximal aortic involvement. The autograft dissection can involve the aortic annulus, causing separation of leaflets from the annulus in addition to causing annular dilatation, thereby precluding resuspension of leaflets. The usual treatment in such cases is to perform the Bentall procedure, which involves placing a valved conduit (usually mechanical valve) and thereby necessitating anticoagulation. This report describes a case of successful valve-sparing aortic root replacement following the Ross procedure with dissection of autograft.  相似文献   
6.
7.
BACKGROUND: Neuroimaging reports of increases in signal hyperintensities in white and deep gray matter and other work indicate that there might be an inflammatory response in affective disorders. METHODS: The microvascular immunoreactivity of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 was measured with image analysis in postmortem tissue from the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) from 15 unipolar and 15 bipolar subjects and compared with each other and with 15 subjects with schizophrenia and 15 control subjects. RESULTS: Intercellular adhesion molecule-1 immunoreactivity in gray and white matter of the ACC in bipolar subjects was increased compared with control subjects (gray: p =.001; white: p <.001) and schizophrenic subjects (gray: p =.016; white: p =.025) and modestly increased in white matter compared with unipolar subjects (p =.049). No such differences were found in the DLPFC. CONCLUSIONS: These findings are consistent with the presence of an inflammatory response in the ACC in bipolar disorder.  相似文献   
8.
Angiosarcoma is a rare, highly malignant tumor arising from endothelial cells of small blood vessels. They usually occur in the skin, deep soft tissues, breast and liver. Pleural angiosarcomas are extremely rare and are restricted to case reports in medical literature. It is very difficult to distinguish them from malignant mesotheliomas on clinical, radiological and even histopathological features. Immunohistochemistry is valuable in making the diagnosis, showing negative reactivity for mesothelial markers and positivity for vascular markers. Prognosis is generally dismal except in occasional cases where the disease is localized and amenable for surgical resection. We report a 55-year-old man who presented to us with chest pain, cough and hemoptysis and was diagnosed to have a pleural angiosarcoma.  相似文献   
9.
The receiver operating characteristic (ROC) method is a useful and popular tool for testing the efficiency of various diagnostic tests applicable to functional MRI (fMRI) data. Typically, the diagnostic tests are applied on simulated and pseudo-human fMRI data, and the area under the ROC curve is used as a measure of the efficiency of the diagnostic test. The effectiveness of such a method depends on how well the simulated data approximate the real data. For multivariate statistical methods, however, this technique is usually inadequate, as the spatial dependence among voxels is ignored for simulated data. In this work a modified ROC method using real fMRI data with a broader scope is proposed. This method can be applied to most fMRI postprocessing techniques, including multivariate analyses such as canonical correlation analysis (CCA). Also, the relationship of the modified ROC method with the conventional ROC method is discussed in detail.  相似文献   
10.
Summary: This study compares the outcomes of 229 renal transplants, of which 156 were live related renal transplants done at our centre and 73 unrelated transplants done at other centres but followed up at our centre. All the patients were on triple immunosuppression for periods varying between 9 months and 1 year. Patient characteristics, rejections, infections and 1 and 5 years patient and graft survival were analyzed in the two groups. the outcome of patients who continued on cyclosporine beyond 1 year was compared to those who discontinued cyclosporine at 1 year. Males predominated (191 vs 38) in both groups, while younger patients (<50 years) predominated in live related group (152 vs four). There was no difference in the incidence of infection, rejection, graft dysfunction, graft loss or death between the two groups. the 1 and 5 year patient survival in the related and unrelated group, (93.7% and 71.4% vs and 85% and 66%) and graft survival (90.4% and 69.4% vs 83.3% and 65.4%) were similar. However, in the unrelated group, patients who discontinued cyclosporine had a higher incidence of rejections (38% vs 14%) and graft loss (43% vs 11.8%), while in the related group no such difference was found. It is concluded that 1 and 5 year patient and graft survival is comparable between live related and live unrelated transplantation. However, in the unrelated group it is necessary to continue cyclosporine beyond 1 year in order to achieve comparable results.  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