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   162895篇
  免费   33301篇
  国内免费   2447篇
耳鼻咽喉   5350篇
儿科学   5724篇
妇产科学   2700篇
基础医学   5030篇
口腔科学   2053篇
临床医学   27705篇
内科学   50630篇
皮肤病学   7690篇
神经病学   15626篇
特种医学   6572篇
外科学   42796篇
综合类   345篇
现状与发展   73篇
一般理论   9篇
预防医学   8263篇
眼科学   3594篇
药学   1838篇
  1篇
中国医学   90篇
肿瘤学   12554篇
  2024年   689篇
  2023年   4878篇
  2022年   1394篇
  2021年   3479篇
  2020年   6248篇
  2019年   2581篇
  2018年   7822篇
  2017年   7624篇
  2016年   8699篇
  2015年   8758篇
  2014年   15919篇
  2013年   16179篇
  2012年   6392篇
  2011年   6406篇
  2010年   10879篇
  2009年   14643篇
  2008年   6490篇
  2007年   4830篇
  2006年   7248篇
  2005年   4460篇
  2004年   3693篇
  2003年   2581篇
  2002年   2607篇
  2001年   4046篇
  2000年   3325篇
  1999年   3467篇
  1998年   3740篇
  1997年   3523篇
  1996年   3423篇
  1995年   3265篇
  1994年   2020篇
  1993年   1614篇
  1992年   1498篇
  1991年   1543篇
  1990年   1174篇
  1989年   1289篇
  1988年   1112篇
  1987年   939篇
  1986年   971篇
  1985年   815篇
  1984年   611篇
  1983年   568篇
  1982年   545篇
  1981年   439篇
  1980年   402篇
  1979年   365篇
  1978年   393篇
  1977年   434篇
  1975年   336篇
  1972年   339篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
33.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  相似文献   
34.
Bowel diseases of prematurity, including necrotizing enterocolitis, are dreaded ailments of neonates. Early diagnosis is difficult, with clinical and radiographic findings often inconclusive. We present a novel use of contrast-enhanced ultrasound in detection of pediatric bowel disease. Early identification of compromised blood flow or an at-risk bowel can be quantitatively detected and monitored. This ability has implications for guidance of emerging therapies, allowing targeting of inflammation. These findings represent an advancement in detection of bowel disease in neonates.  相似文献   
35.
The association between asbestos exposure, mainly in occupational settings, and malignant mesothelioma has been well established; this has prompted several countries to establish mesothelioma epidemiologic surveillance programs often at the request of national agencies. This review compares currently existing mesothelioma registries worldwide to develop a concept model for a US real-time case capture mesothelioma registry. Five countries were identified with a mesothelioma specific registry, including Italy, France, UK, Australia, and South Korea. All, except the UK, used interviews to collect exposure data. Linkage with the national death index was available or was in future plans for all registries. The registries have limited information on treatment, quality of life, and other patient-centered outcomes such as symptoms and pain management. To thoroughly collect exposure data, “real-time” enrollment is preferable; to maximize the capture of mesothelioma cases, optimal coverage, and a simplified consent process are needed.  相似文献   
36.
37.
38.
39.
40.
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