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   5200篇
  免费   199篇
  国内免费   23篇
耳鼻咽喉   10篇
儿科学   136篇
妇产科学   169篇
基础医学   578篇
口腔科学   70篇
临床医学   378篇
内科学   750篇
皮肤病学   36篇
神经病学   331篇
特种医学   195篇
外科学   384篇
综合类   78篇
现状与发展   2篇
预防医学   1245篇
眼科学   47篇
药学   664篇
中国医学   27篇
肿瘤学   322篇
  2024年   7篇
  2023年   281篇
  2022年   318篇
  2021年   313篇
  2020年   349篇
  2019年   208篇
  2018年   177篇
  2017年   314篇
  2016年   307篇
  2015年   271篇
  2014年   393篇
  2013年   308篇
  2012年   250篇
  2011年   160篇
  2010年   249篇
  2009年   273篇
  2008年   95篇
  2007年   100篇
  2006年   99篇
  2005年   38篇
  2004年   43篇
  2003年   60篇
  2002年   68篇
  2001年   70篇
  2000年   42篇
  1999年   68篇
  1998年   70篇
  1997年   70篇
  1996年   71篇
  1995年   65篇
  1994年   53篇
  1993年   29篇
  1992年   26篇
  1991年   18篇
  1990年   22篇
  1989年   13篇
  1988年   36篇
  1987年   42篇
  1986年   40篇
  1985年   5篇
  1984年   1篇
排序方式: 共有5422条查询结果,搜索用时 15 毫秒
121.
The ACR recognizes that low-dose CT for lung cancer screening has the potential to significantly reduce mortality from lung cancer in the appropriate high-risk population. The ACR supports the recommendations of the US Preventive Services Task Force and the National Comprehensive Cancer Network for screening patients. To be effective, lung cancer screening should be performed at sites providing high-quality low-dose CT examinations overseen and interpreted by qualified physicians using a structured reporting and management system. The ACR has developed a set of tools necessary for radiologists to take the lead on the front lines of lung cancer screening. The ACR Lung Cancer Screening Center designation is built upon the ACR CT accreditation program and requires use of Lung-RADS or a similar structured reporting and management system. This designation provides patients and referring providers with the assurance that they will receive high-quality screening with appropriate follow-up care.  相似文献   
122.
Exposure of fragrance ingredients in cosmetics and personal care products to the population can be determined by way of a detailed and robust survey. The frequency and combinations of products used at specific times during the day will allow the estimation of aggregate exposure for an individual consumer, and to the sample population. In the present study, habits and practices of personal care and cosmetic products have been obtained from market research data for 36,446 subjects across European countries and the United States in order to determine the exposure to fragrance ingredients. Each subject logged their product uses, time of day and body application sites in an online diary for seven consecutive days. The survey data did not contain information on the amount of product used per occasion or body measurements, such as weight and skin surface area. Nevertheless, this was found from the literature where the likely amount of product used per occasion or body measurement could be probabilistically chosen from distributions of data based on subject demographics. The daily aggregate applied consumer product exposure was estimated based on each subject’s frequency of product use, and Monte Carlo simulations of their likely product amount per use and body measurements. Statistical analyses of the habits and practices and consumer product exposure are presented, which show the robustness of the data and the ability to estimate aggregate consumer product exposure. Consequently, the data and modelling methods presented show potential as a means of performing ingredient safety assessments for personal care and cosmetics products.  相似文献   
123.
124.
125.
126.
127.
Natural environments may be important for subjective wellbeing, yet evidence is sparse and measures of nature are unspecific. We used linear regression models to investigate the relationship between greenness, biodiversity and blue space and subjective wellbeing in 4,912 adults living in metropolitan Melbourne, Australia. Greenness (overall, private and public) and biodiversity associated with subjective wellbeing. In particular, we highlight the importance of the private greenness-subjective wellbeing association. Our work has implications for urban policy and planning in the context of increased urban densification.  相似文献   
128.
129.
130.
“Consortium Linking Academic and Regulatory Insights on BPA Toxicity” (CLARITY-BPA) was a comprehensive “industry-standard” Good Laboratory Practice (GLP)-compliant 2-year chronic exposure study of bisphenol A (BPA) toxicity that was supplemented by hypothesis-driven independent investigator-initiated studies. The investigator-initiated studies were focused on integrating disease-associated, molecular, and physiological endpoints previously found by academic scientists into an industry standard guideline-compliant toxicity study. Thus, the goal of this collaboration was to provide a more comprehensive dataset upon which to base safety standards and to determine whether industry-standard tests are as sensitive and predictive as molecular and disease-associated endpoints. The goal of this report is to integrate the findings from the investigator-initiated studies into a comprehensive overview of the observed impacts of BPA across the multiple organs and systems analyzed. For each organ system, we provide the rationale for the study, an overview of methodology, and summarize major findings. We then compare the results of the CLARITY-BPA studies across organ systems with the results of previous peer-reviewed studies from independent labs. Finally, we discuss potential influences that contributed to differences between studies. Developmental exposure to BPA can lead to adverse effects in multiple organs systems, including the brain, prostate gland, urinary tract, ovary, mammary gland, and heart. As published previously, many effects were at the lowest dose tested, 2.5μg/kg /day, and many of the responses were non-monotonic. Because the low dose of BPA affected endpoints in the same animals across organs evaluated in different labs, we conclude that these are biologically – and toxicologically – relevant.  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