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   970966篇
  免费   70612篇
  国内免费   1462篇
耳鼻咽喉   13509篇
儿科学   25390篇
妇产科学   23736篇
基础医学   137951篇
口腔科学   28697篇
临床医学   84865篇
内科学   191209篇
皮肤病学   19670篇
神经病学   76148篇
特种医学   38325篇
外国民族医学   79篇
外科学   159695篇
综合类   18362篇
现状与发展   2篇
一般理论   288篇
预防医学   65242篇
眼科学   22019篇
药学   75108篇
  3篇
中国医学   2196篇
肿瘤学   60546篇
  2021年   7410篇
  2019年   7448篇
  2018年   10780篇
  2017年   8306篇
  2016年   9038篇
  2015年   10278篇
  2014年   14033篇
  2013年   19960篇
  2012年   27965篇
  2011年   28816篇
  2010年   16815篇
  2009年   15927篇
  2008年   27232篇
  2007年   28458篇
  2006年   28788篇
  2005年   27482篇
  2004年   26360篇
  2003年   25124篇
  2002年   24461篇
  2001年   54875篇
  2000年   56673篇
  1999年   47109篇
  1998年   10965篇
  1997年   9649篇
  1996年   9724篇
  1995年   9045篇
  1994年   8367篇
  1993年   7667篇
  1992年   35549篇
  1991年   33958篇
  1990年   32768篇
  1989年   31903篇
  1988年   29031篇
  1987年   28290篇
  1986年   26318篇
  1985年   25182篇
  1984年   17877篇
  1983年   15173篇
  1982年   7833篇
  1979年   15796篇
  1978年   10615篇
  1977年   9062篇
  1976年   7881篇
  1975年   8640篇
  1974年   10485篇
  1973年   9873篇
  1972年   9371篇
  1971年   8862篇
  1970年   8434篇
  1969年   7926篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
42.
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   
43.
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   
44.
45.
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   
46.
47.
48.
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction.  相似文献   
49.
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