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   2341995篇
  免费   183156篇
  国内免费   3938篇
耳鼻咽喉   32500篇
儿科学   71934篇
妇产科学   64469篇
基础医学   333874篇
口腔科学   70832篇
临床医学   206019篇
内科学   456626篇
皮肤病学   50231篇
神经病学   186797篇
特种医学   93824篇
外国民族医学   541篇
外科学   363617篇
综合类   53898篇
现状与发展   6篇
一般理论   761篇
预防医学   172380篇
眼科学   53974篇
药学   179774篇
  6篇
中国医学   5124篇
肿瘤学   131902篇
  2018年   22427篇
  2016年   19795篇
  2015年   23084篇
  2014年   31286篇
  2013年   46712篇
  2012年   63608篇
  2011年   66555篇
  2010年   39351篇
  2009年   37436篇
  2008年   63479篇
  2007年   66634篇
  2006年   67663篇
  2005年   65624篇
  2004年   64106篇
  2003年   61346篇
  2002年   59987篇
  2001年   116043篇
  2000年   120251篇
  1999年   101517篇
  1998年   26183篇
  1997年   23650篇
  1996年   23590篇
  1995年   22685篇
  1994年   21185篇
  1993年   19851篇
  1992年   81880篇
  1991年   79210篇
  1990年   77159篇
  1989年   74870篇
  1988年   69084篇
  1987年   67899篇
  1986年   64204篇
  1985年   62015篇
  1984年   45525篇
  1983年   39072篇
  1982年   22097篇
  1981年   19621篇
  1980年   18270篇
  1979年   42605篇
  1978年   29182篇
  1977年   24818篇
  1976年   22794篇
  1975年   24493篇
  1974年   29776篇
  1973年   28543篇
  1972年   26509篇
  1971年   24985篇
  1970年   23302篇
  1969年   21884篇
  1968年   19951篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development.  相似文献   
92.
93.
Annals of Nuclear Medicine - The Response Evaluation Criteria In Solid Tumors (RECIST) is the most used radiological method for evaluating response after peptide receptor radionuclide therapy...  相似文献   
94.
95.
96.
To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects arou  相似文献   
97.
98.
99.
Advancement in microelectromechanical system has facilitated the microfabrication of polymeric substrates and the development of the novel class of controlled drug delivery devices. These vehicles have specifically tailored three dimensional physical and chemical features which together, provide the capacity to target cell, stimulate unidirectional controlled release of therapeutics and augment permeation across the barriers. Apart from drug delivery devices microfabrication technology’s offer exciting prospects to generate biomimetic gastrointestinal tract models. BioMEMS are capable of analysing biochemical liquid sample like solution of metabolites, macromolecules, proteins, nucleic acid, cells and viruses. This review summarized multidisciplinary application of biomedical microelectromechanical systems in drug delivery and its potential in analytical procedures.  相似文献   
100.
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   
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