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   715722篇
  免费   50581篇
  国内免费   1361篇
耳鼻咽喉   9277篇
儿科学   23580篇
妇产科学   17809篇
基础医学   111548篇
口腔科学   20449篇
临床医学   64691篇
内科学   136834篇
皮肤病学   16366篇
神经病学   50066篇
特种医学   26062篇
外国民族医学   80篇
外科学   106150篇
综合类   15290篇
现状与发展   2篇
一般理论   169篇
预防医学   52087篇
眼科学   16614篇
药学   54871篇
  3篇
中国医学   2421篇
肿瘤学   43295篇
  2021年   6176篇
  2019年   5893篇
  2018年   8420篇
  2017年   6415篇
  2016年   7183篇
  2015年   7908篇
  2014年   10742篇
  2013年   15988篇
  2012年   21350篇
  2011年   22337篇
  2010年   13147篇
  2009年   12306篇
  2008年   20537篇
  2007年   22054篇
  2006年   22384篇
  2005年   20927篇
  2004年   20478篇
  2003年   19324篇
  2002年   18848篇
  2001年   36400篇
  2000年   36948篇
  1999年   30425篇
  1998年   7952篇
  1997年   6703篇
  1996年   7008篇
  1995年   6677篇
  1994年   6130篇
  1992年   22986篇
  1991年   22955篇
  1990年   22337篇
  1989年   22105篇
  1988年   20056篇
  1987年   19439篇
  1986年   18494篇
  1985年   17322篇
  1984年   12715篇
  1983年   10760篇
  1982年   5932篇
  1979年   11531篇
  1978年   8138篇
  1977年   6842篇
  1976年   6599篇
  1975年   7276篇
  1974年   8508篇
  1973年   8147篇
  1972年   7662篇
  1971年   7131篇
  1970年   6884篇
  1969年   6310篇
  1968年   5785篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
56.
57.
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   
58.
59.
60.
Doxorubicin (DOX) is the most commonly used anticancer drug; however, it has limited use because prolonged administration may result in severe cardiotoxicity. Simvastatin (SIM), generally prescribed for hypercholesterolaemia, has also shown salubrious results in the monotherapy or combinational drug therapy of different cancers in various models. Nanoparticle drug delivery systems are a novel way of improving therapeutics and also improving the absorption and specificity of drugs towards tumour cells. In this study, we exploited this technology to increase drug specificity and minimize imminent adverse effects. In this study, the antitumour activity of the combination formulas of DOX and SIM, either loaded in water (DOX‐SIM‐Solution) or nanoemulsions (NEs) (DOX‐SIM‐NE), was evaluated in a Swiss albino mouse model of Ehrlich ascites carcinoma. The anticancer effect was assessed by quantifying the change in body weight, mean survival time, and percent increase in lifespan (%ILS), determining haematological and serum biochemical parameters (liver function test, kidney function test and lipid profile parameters) as well as studying the histopathological alterations in liver tissues. We observed a clear increase in %ILS of the DOX‐SIM‐Solution group (265.30) that was double the %ILS of the DOX‐SIM‐NE group (134.70). However, DOX‐SIM‐NE had a non‐toxic effect on the haematological parameters, whereas DOX‐SIM‐Solution increased the levels of haemoglobin and lymphocytes. Furthermore, the encapsulation of SIM and DOX into NEs improved the levels of all serum biochemical parameters compared to the DOX‐SIM‐Solution. A reduction in the side effects of DOX‐SIM‐NE on the liver was also established using light microscopy, which revealed that the morphologies of the hepatocytes of the mice were less affected by administration of the DOX‐SIM‐NE treatment than with the DOX‐SIM‐Solution treatment. The study showed that incorporating SIM into the DOX‐loaded‐NE formulation remarkably improved its efficiency and simultaneously reduced its adverse effects.  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