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   1346篇
  免费   99篇
  国内免费   11篇
耳鼻咽喉   1篇
儿科学   57篇
妇产科学   39篇
基础医学   144篇
口腔科学   44篇
临床医学   159篇
内科学   292篇
皮肤病学   18篇
神经病学   110篇
特种医学   131篇
外科学   169篇
综合类   42篇
一般理论   2篇
预防医学   59篇
眼科学   10篇
药学   72篇
肿瘤学   107篇
  2021年   16篇
  2020年   18篇
  2019年   15篇
  2018年   34篇
  2017年   22篇
  2016年   12篇
  2015年   35篇
  2014年   29篇
  2013年   24篇
  2012年   49篇
  2011年   58篇
  2010年   47篇
  2009年   45篇
  2008年   58篇
  2007年   55篇
  2006年   65篇
  2005年   40篇
  2004年   45篇
  2003年   27篇
  2002年   30篇
  2001年   33篇
  2000年   40篇
  1999年   40篇
  1998年   45篇
  1997年   35篇
  1996年   56篇
  1995年   30篇
  1994年   26篇
  1993年   24篇
  1992年   27篇
  1991年   27篇
  1990年   26篇
  1989年   24篇
  1988年   29篇
  1987年   24篇
  1986年   18篇
  1985年   26篇
  1984年   23篇
  1983年   17篇
  1982年   19篇
  1981年   19篇
  1980年   15篇
  1979年   10篇
  1978年   10篇
  1977年   10篇
  1976年   11篇
  1975年   6篇
  1973年   8篇
  1972年   12篇
  1971年   6篇
排序方式: 共有1456条查询结果,搜索用时 15 毫秒
61.
    
Background Adolescent intake of animal products has been proposed to contribute to prostate cancer (PCa) development because of its potentially carcinogenic constituents and influence on hormone levels during adolescence.Methods We used data from 159,482 participants in the NIH-AARP Diet and Health Study to investigate associations for recalled adolescent intake of red meat (unprocessed beef and processed red meat), poultry, egg, canned tuna, animal fat and animal protein at ages 12–13 years with subsequent PCa risk and mortality over 14 years of follow-up. Cox proportional hazard regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of total (n = 17,349), advanced (n = 2,297) and fatal (n = 804) PCa.Results Suggestive inverse trends were observed for adolescent unprocessed beef intake with risks of total, advanced and fatal PCa (multivariable-adjusted P-trends = 0.01, 0.02 and 0.04, respectively). No consistent patterns of association were observed for other animal products by PCa outcome.Conclusion We found evidence to suggest that adolescent unprocessed beef intake, or possibly a correlate of beef intake, such as early-life socioeconomic status, may be associated with reduced risk and mortality from PCa. Additional studies with further early-life exposure information are warranted to better understand this association.Subject terms: Epidemiology, Risk factors  相似文献   
62.
63.

Background  

Ischemic stroke is the most common cause of disability in North America and in addition to the generally accepted risk factors, there is increasing evidence for the potential pathophysiological role of genes. One of these genes, the endothelial nitric oxide synthase gene (NOS3) has been reported as a genetic risk factor for ischemic stroke. To independently confirm and extend the results of these previous reports, we investigated this gene as a risk factor for stroke in an ethnically diverse study population.  相似文献   
64.
CJ-21,058, a new SecA inhibitor isolated from a fungus   总被引:1,自引:0,他引:1  
A new equisetin derivative, CJ-21,058 (I) was isolated from the fermentation broth of an unidentified fungus CL47745. It shows antibacterial activity against Gram-positive multi-drug resistant bacteria by inhibiting ATP-dependent translocation of precursor proteins across a bacterial cell membrane.  相似文献   
65.
66.
Agene encoding olfactomedin-related glycoprotein was isolated from rat glomerulus despite its prior identification as a neuron-specific gene. The mRNA expression was remarkably intense in renal glomerulus and brain and faint in the lung and eye among rat systemic organs. Although the brain contained four mRNA variants (AMY, AMZ, BMY, and BMZ) transcribed from a single gene, the glomerulus, lung, and eye expressed only two variants (BMZ and BMY). The glycoprotein was intensely immunolocalized in glomerular podocytes and neurons by using an antibody against synthetic peptide of the M region, but weak in endothelial cells of the kidney and lung. Bronchiolar epithelial cells in the lung, and ciliary, corneal, and iris epithelial cells in the eye were also stained. Immunogold electron microscopy revealed selective localization of olfactomedin-related glycoprotein at the Golgi apparatus in podocytes. In glomerular culture, the staining was also intense at a juxtanuclear region in synaptopodin-positive epithelial cells of irregular shape (phenotypic feature of podocytes), whereas it was weak in synaptopodin-negative ones of cobblestone-like appearance (phenotypic feature of parietal epithelial cells of Bowman's capsule). Interestingly, Western blot analysis identified an intense band corresponding to BMZ isoform and another faint band corresponding to BMY isoform in the glomerulus, whereas the intensity of these two bands were nearly equal in the lung and eye. In the brain, four bands corresponding to four isoforms were observed apparently. Computer sequence analysis predicted coiled-coil structures in the secondary structure of the glycoprotein similar to those in Golgi autoantigens, suggesting significant roles in the unique functions of the Golgi apparatus in rat podocytes and neurons.  相似文献   
67.
The peak incidence of Hodgkin's disease occurs during the reproductive age, and its association with pregnancy is at a rate of between 1:1,000-1:6,000. We studied the effects of Hodgkin's Disease on the course and survival of 48 women who had Hodgkin's Disease and who were pregnant, and compared their outcome with non-pregnant matched women who were of similar stage of disease, age at diagnosis, and calenderic year of treatment. Twenty-year survival of pregnant women with Hodgkin's Disease was not different from that of their matched controls. Pregnant women with Hodgkin's Disease had similar distribution of stages to the controls.  相似文献   
68.
69.
The future of neurodegenerative therapeutics development depends upon effective disease modification strategies centered on carefully investigated targets. Pharmaceutical research endeavors that probe for a much deeper understanding of disease pathogenesis, and explain how adaptive or compensatory mechanisms might be engaged to delay disease onset or progression, will produce the needed breakthroughs. Below, we discuss the prospects for new targets emerging out of the study of brain disease genes and their associated pathogenic pathways. We describe a general experimental paradigm that we are employing across several mouse models of neurodegenerative disease to elucidate molecular determinants of selective neuronal vulnerability. We outline key elements of our target discovery program and provide examples of how we integrate genomic technologies, neuroanatomical methods, and mouse genetics in the search for neurodegenerative disease targets.  相似文献   
70.
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