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   9974篇
  免费   899篇
  国内免费   84篇
耳鼻咽喉   58篇
儿科学   411篇
妇产科学   172篇
基础医学   1352篇
口腔科学   245篇
临床医学   1227篇
内科学   2120篇
皮肤病学   161篇
神经病学   653篇
特种医学   617篇
外科学   1409篇
综合类   229篇
一般理论   9篇
预防医学   946篇
眼科学   118篇
药学   615篇
  2篇
肿瘤学   613篇
  2021年   98篇
  2020年   79篇
  2019年   116篇
  2018年   170篇
  2017年   106篇
  2016年   105篇
  2015年   140篇
  2014年   194篇
  2013年   308篇
  2012年   387篇
  2011年   396篇
  2010年   258篇
  2009年   266篇
  2008年   406篇
  2007年   459篇
  2006年   438篇
  2005年   407篇
  2004年   369篇
  2003年   324篇
  2002年   363篇
  2001年   326篇
  2000年   301篇
  1999年   250篇
  1998年   229篇
  1997年   238篇
  1996年   205篇
  1995年   184篇
  1994年   177篇
  1993年   186篇
  1992年   223篇
  1991年   209篇
  1990年   239篇
  1989年   219篇
  1988年   199篇
  1987年   191篇
  1986年   187篇
  1985年   192篇
  1984年   147篇
  1983年   100篇
  1982年   86篇
  1981年   91篇
  1980年   82篇
  1979年   119篇
  1978年   89篇
  1976年   97篇
  1975年   87篇
  1974年   86篇
  1973年   82篇
  1972年   87篇
  1969年   81篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
2.
3.
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   
4.
5.
6.
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   
7.
8.
9.
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   
10.
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