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   742835篇
  免费   52081篇
  国内免费   1363篇
耳鼻咽喉   9545篇
儿科学   24420篇
妇产科学   18426篇
基础医学   116334篇
口腔科学   20240篇
临床医学   67194篇
内科学   143120篇
皮肤病学   17111篇
神经病学   52991篇
特种医学   26873篇
外国民族医学   106篇
外科学   109328篇
综合类   14900篇
现状与发展   2篇
一般理论   169篇
预防医学   54037篇
眼科学   16935篇
药学   56581篇
  3篇
中国医学   2433篇
肿瘤学   45531篇
  2021年   6045篇
  2019年   6082篇
  2018年   8934篇
  2017年   6889篇
  2016年   7582篇
  2015年   8471篇
  2014年   11285篇
  2013年   16948篇
  2012年   23099篇
  2011年   24061篇
  2010年   14007篇
  2009年   13009篇
  2008年   22307篇
  2007年   23867篇
  2006年   24120篇
  2005年   22806篇
  2004年   22360篇
  2003年   21085篇
  2002年   20469篇
  2001年   37311篇
  2000年   37922篇
  1999年   31229篇
  1998年   8101篇
  1997年   6836篇
  1996年   7134篇
  1995年   6776篇
  1994年   6227篇
  1992年   23446篇
  1991年   23350篇
  1990年   22757篇
  1989年   22479篇
  1988年   20396篇
  1987年   19788篇
  1986年   18784篇
  1985年   17603篇
  1984年   12908篇
  1983年   10914篇
  1982年   6035篇
  1979年   11675篇
  1978年   8221篇
  1977年   6918篇
  1976年   6678篇
  1975年   7348篇
  1974年   8614篇
  1973年   8254篇
  1972年   7766篇
  1971年   7238篇
  1970年   6979篇
  1969年   6436篇
  1968年   5893篇
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
51.
52.
53.
54.
55.
56.
57.
58.
In the United States, renal cell carcinoma (RCC) incidence and the prevalence of obesity, an established risk factor for RCC, have been increasing for several decades. RCC is more common among older individuals. We sought to quantify the contribution of excess adiposity to the rising incidence of RCC among individuals 60 years or older. National Institutes of Health-American Association of Retired Persons Diet and Health Study data (n = 453 859 participants, enrolled in 1995-1996, age at enrollment 50-71 years) were used to estimate multivariable-adjusted hazard ratios (HRs) for RCC across body mass index categories and HRs associated with smoking. Population attributable fractions (PAFs) were calculated using estimated HRs and annual overweight/obesity prevalence from the National Health Interview Survey (1985-2008). PAF estimates were combined with RCC incidence from Surveillance, Epidemiology and End Results-13 to calculate annual percent changes in RCC incidence attributable (and unrelated) to overweight/obesity. We found that between 1995 and 2018, among individuals aged 60 years and older, PAF for overweight/obesity increased from 18% to 29% for all RCCs. In comparison, the PAF for smoking declined from 12% to 9%. RCC incidence increased 1.8% per year (95% confidence interval [CI] 1.5%-2.1%) overall, while RCC incidence attributable to overweight/obesity increased 3.8% per year (95%CI 3.5%-4.2%) and RCC incidence unrelated to overweight/obesity increased 1.2% per year (95% CI 0.9%-1.4%). In conclusion, overweight/obesity appears to have contributed importantly to the rising incidence of RCC in the United States since the mid-1990s. Public health interventions focused on reducing overweight and obesity could help substantially in curbing this trend.  相似文献   
59.
Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.  相似文献   
60.
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