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   2403346篇
  免费   201857篇
  国内免费   7044篇
耳鼻咽喉   35012篇
儿科学   73127篇
妇产科学   63451篇
基础医学   338029篇
口腔科学   68396篇
临床医学   219903篇
内科学   470916篇
皮肤病学   48535篇
神经病学   201998篇
特种医学   98128篇
外国民族医学   907篇
外科学   364209篇
综合类   62154篇
一般理论   979篇
预防医学   191718篇
眼科学   56455篇
药学   181990篇
  27篇
中国医学   6627篇
肿瘤学   129686篇
  2018年   25909篇
  2017年   20420篇
  2016年   21944篇
  2015年   25626篇
  2014年   36394篇
  2013年   53531篇
  2012年   72593篇
  2011年   76417篇
  2010年   45104篇
  2009年   42913篇
  2008年   71338篇
  2007年   75615篇
  2006年   76339篇
  2005年   74275篇
  2004年   70912篇
  2003年   68425篇
  2002年   67393篇
  2001年   113060篇
  2000年   116974篇
  1999年   98534篇
  1998年   26693篇
  1997年   24314篇
  1996年   24156篇
  1995年   24841篇
  1994年   23378篇
  1993年   21624篇
  1992年   79523篇
  1991年   76582篇
  1990年   73723篇
  1989年   70978篇
  1988年   65937篇
  1987年   64886篇
  1986年   61392篇
  1985年   58449篇
  1984年   44197篇
  1983年   37579篇
  1982年   22809篇
  1981年   20249篇
  1979年   41245篇
  1978年   28925篇
  1977年   24261篇
  1976年   22773篇
  1975年   23915篇
  1974年   29602篇
  1973年   28018篇
  1972年   26214篇
  1971年   24149篇
  1970年   22732篇
  1969年   21070篇
  1968年   19118篇
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
1.
我国奶牛养殖规模不断扩大,奶业产值比重逐步提高,给奶牛疫病防治带来巨大压力。奶牛乳房炎及细菌性肺炎等呼吸系统疾病和细菌性肠炎等消化系统疾病最为常见,抗菌药物的使用成为主要防治手段。但抗菌药物的不当使用易使细菌产生耐药性,增加临床治疗的成本和难度,危害我国奶牛产业发展。本文对截至2021年7月我国和美国、英国、日本、欧盟批准用于奶牛的抗菌药物产品进行整理、统计与分析,包括抗菌药物的分类、剂型以及适应证等,旨在为我国奶牛用抗菌药物管理、合理用药和新兽药开发提供参考。  相似文献   
2.
The International Journal of Cardiovascular Imaging - Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of...  相似文献   
3.
4.
5.
6.
7.
The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.  相似文献   
8.
9.
10.
Minimally invasive approaches are increasingly being applied in surgeries and have recently been used in living donor hepatectomy. We have developed a safe and reproducible method for minimally invasive living donor liver transplantation, which consists of pure laparoscopic explant hepatectomy and pure laparoscopic implantation of the graft, which was inserted through a suprapubic incision. Pure laparoscopic explant hepatectomy without liver fragmentation was performed in a 60-year-old man with alcoholic liver cirrhosis and hepatocellular carcinoma. The explanted liver was retrieved through a suprapubic incision. A modified right liver graft, procured from his 24-year-old son using the pure laparoscopic method, was inserted through a suprapubic incision, and implantation was performed intracorporeally throughout the procedure. The time required to remove the liver was 369 min, and the total operative time was 960 min. No complications occurred during or after the surgery. The patient recovered well, and his hospital stay was of 11 days. Pure laparoscopic living donor liver transplantation from explant hepatectomy to implantation was performed successfully. It is a feasible procedure when performed by a highly experienced surgeon and transplantation team. Further studies with larger sample sizes are needed to confirm its safety and feasibility.

  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