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   8184篇
  免费   793篇
  国内免费   10篇
耳鼻咽喉   58篇
儿科学   247篇
妇产科学   148篇
基础医学   1141篇
口腔科学   192篇
临床医学   987篇
内科学   1661篇
皮肤病学   89篇
神经病学   596篇
特种医学   278篇
外科学   1335篇
综合类   223篇
一般理论   9篇
预防医学   862篇
眼科学   107篇
药学   539篇
  1篇
肿瘤学   514篇
  2021年   88篇
  2020年   69篇
  2019年   107篇
  2018年   143篇
  2017年   86篇
  2016年   85篇
  2015年   105篇
  2014年   151篇
  2013年   258篇
  2012年   357篇
  2011年   364篇
  2010年   178篇
  2009年   188篇
  2008年   364篇
  2007年   378篇
  2006年   397篇
  2005年   361篇
  2004年   350篇
  2003年   309篇
  2002年   338篇
  2001年   291篇
  2000年   278篇
  1999年   224篇
  1998年   111篇
  1997年   102篇
  1996年   89篇
  1995年   85篇
  1994年   73篇
  1993年   100篇
  1992年   196篇
  1991年   177篇
  1990年   204篇
  1989年   173篇
  1988年   154篇
  1987年   153篇
  1986年   139篇
  1985年   147篇
  1984年   121篇
  1983年   86篇
  1982年   62篇
  1981年   64篇
  1979年   115篇
  1978年   83篇
  1976年   74篇
  1975年   73篇
  1974年   86篇
  1973年   82篇
  1972年   87篇
  1970年   66篇
  1969年   81篇
排序方式: 共有8987条查询结果,搜索用时 15 毫秒
1.
Cancer Chemotherapy and Pharmacology - Addition of solid doxorubicin or solutions to pre-formed liposomes proved to be the optimal method for incorporating the drug into liposomes whilst...  相似文献   
2.
3.
4.
This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty‐four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use.  相似文献   
5.
6.
7.
R C Hunt  D M Bryan  V S Brinkley  T W Whitley  N H Benson 《JAMA》1991,265(15):1982-1984
This study assessed the capabilities of a traditional and an amplified stethoscope used by flight nurses to assess breath sound during air medical transport in an MBB BO-105 helicopter. We developed a normal breath sound model using a prerecorded tape of breath sounds interspersed with segments without breath sounds; the recorder had been placed in the chest wall of a resuscitation training manikin. Flight nurses completed control listening sessions in a quiet environment and experimental sessions during flight using a traditional stethoscope for half of the sessions and an amplified stethoscope for the remaining half. In the quiet environment, flight nurses accurately reported the presence or absence of breath sounds in 110 (92%) of 120 trials. During helicopter flight, none of the flight nurses heard breath sounds during any of the recorded segments with either the traditional stethoscope or the amplified stethoscope. We conclude that flight nurses are unable to hear normal breath sounds using a traditional or amplified stethoscope during flight in a medically configured MBB BO-105 helicopter. Improved stethoscopes, innovative methods of listening, and reduction of aircraft noise are potential solutions to the problems of breath sound assessment during air medical transport.  相似文献   
8.
9.
10.
Most publications citing the effectiveness of renal extracorporeal shock wave lithotripsy have used plain abdominal radiography to assess residual calculi after treatment. We compared radiologist sensitivity and specificity in the detection of calculi on plain abdominal radiographs versus conventional film-screen and digital renal tomograms in extracorporeal shock wave lithotripsy patients. Of the patients 50 were imaged before and within 24 hours after lithotripsy. Six radiologists evaluated the resultant 300 studies for the presence and location of calculi. The mean sensitivity for digital tomograms was 83% for pre-lithotripsy and post-lithotripsy studies, which was significantly higher than for plain abdominal radiography and conventional tomography after lithotripsy. However, there were significantly more false positive stone diagnoses associated with digital tomogram interpretation. Signal detection analysis verified the over-all superiority of digital tomography for post-extracorporeal shock wave lithotripsy imaging. Calculus detection by conventional and digital tomography is superior to detection by plain abdominal radiography. However, because we did not perform delayed imaging, it is not possible to say what impact digital tomography might have on the management of extracorporeal shock wave lithotripsy patients.  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