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   3532642篇
  免费   267460篇
  国内免费   7043篇
耳鼻咽喉   50058篇
儿科学   112322篇
妇产科学   94804篇
基础医学   497618篇
口腔科学   103292篇
临床医学   321631篇
内科学   683530篇
皮肤病学   75315篇
神经病学   287014篇
特种医学   137372篇
外国民族医学   1084篇
外科学   532749篇
综合类   84058篇
现状与发展   6篇
一般理论   1396篇
预防医学   278823篇
眼科学   84637篇
药学   263349篇
  11篇
中国医学   7640篇
肿瘤学   190436篇
  2018年   37971篇
  2017年   28999篇
  2016年   32221篇
  2015年   36656篇
  2014年   51941篇
  2013年   77773篇
  2012年   105935篇
  2011年   111810篇
  2010年   66270篇
  2009年   62474篇
  2008年   104870篇
  2007年   111607篇
  2006年   112521篇
  2005年   109068篇
  2004年   104950篇
  2003年   100671篇
  2002年   98424篇
  2001年   166831篇
  2000年   172075篇
  1999年   144856篇
  1998年   41171篇
  1997年   36721篇
  1996年   36371篇
  1995年   35186篇
  1994年   32848篇
  1993年   30443篇
  1992年   114865篇
  1991年   111197篇
  1990年   107293篇
  1989年   103643篇
  1988年   95715篇
  1987年   94023篇
  1986年   88872篇
  1985年   84774篇
  1984年   63824篇
  1983年   54386篇
  1982年   32229篇
  1981年   28782篇
  1979年   58799篇
  1978年   41076篇
  1977年   34895篇
  1976年   32655篇
  1975年   34471篇
  1974年   42427篇
  1973年   40476篇
  1972年   37890篇
  1971年   34991篇
  1970年   32874篇
  1969年   30590篇
  1968年   28090篇
排序方式: 共有10000条查询结果,搜索用时 30 毫秒
111.
There are no data available combining transbronchial needle aspiration (TBNA) of mediastinal lymph nodes and positron emission tomography (PET) in the staging of nonsmall cell lung cancer (NSCLC). The aim of the current study was to determine if these two methods can enhance the negative predictive value of the individual modality alone, for a specific lymph node station, and if this integrated approach can reduce the number of mediastinoscopies. A total of 113 patients with enlarged mediastinal lymph nodes (> or = 1 cm), who underwent both TBNA and PET scanning, were included. In 51 patients, histopathology, confirmed by surgical lymph node dissection, was compared with PET results and TBNA. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to detect malignant lymphadenopathy was 68 (13/19), 89 (119/134), 46 (13/28), 95 (119/125) and 86% (132/152) for PET, respectively; 54% (6/11), 100 (53/53), 100 (6/6), 91 (53/58) and 92% (59/64), respectively for TBNA; and 100 (11/11), 94 (50/53), 79 (11/14), 100 (50/50) and 95 (61/64) for combined TBNA and PET, respectively. Combination of transbronchial needle aspiration and positron emission tomography has the potential to allow adequate mediastinal staging of nonsmall cell lung cancer with enlarged lymph nodes in most patients without the need for mediastinoscopy.  相似文献   
112.
113.
114.
Group A streptococcal meningitis is less common than other forms of meningitis; however, the occurrence of this infection is associated with high mortality and morbidity. Early recognition and a prompt treatment are therefore essential. We review one case of an Asian women admitted with group A streptococcal meningitis as a complication of otitis media.  相似文献   
115.
116.
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   
117.
118.
High levels of tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, are present in the wound fluid of chronic nonhealing wounds. This leads to increased inflammation, cytokine expression, and ultimately results in impaired wound healing and tissue destruction. Etanercept is a recombinant fusion protein that consists of the soluble TNF receptor (p75) linked to the Fc portion of human IgG1. It is an effective inhibitor of TNF-alpha and has been shown to provide rapid and sustained improvement in rheumatoid arthritis by acting as a soluble receptor binding TNF-alpha and preventing its proinflammatory activities. Therefore, the aim of this study was to determine whether Etanercept could inhibit TNF-alpha activity in chronic wound fluid. Wound fluid was collected from the venous leg ulcers of 16 different patients. The effect of Etanercept on TNF-alpha activity was evaluated using both a TNF-alpha bioassay and an enzyme-linked immunoassay. Etanercept was found to reduce the cytotoxic effect of chronic wound fluid on L929 fibroblasts by approximately 30% and neutralized TNF-alpha binding in the enzyme-linked immunoassay by up to 80%. Direct application of Etanercept to chronic wounds may therefore reduce the inflammatory activity of TNF-alpha, which could reduce the chronicity of venous leg ulcers and thus aid in the healing of these wounds.  相似文献   
119.
120.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants.  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