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   2999656篇
  免费   218146篇
  国内免费   5120篇
耳鼻咽喉   41218篇
儿科学   99023篇
妇产科学   81698篇
基础医学   439398篇
口腔科学   83698篇
临床医学   272185篇
内科学   577161篇
皮肤病学   66659篇
神经病学   237518篇
特种医学   113117篇
外国民族医学   768篇
外科学   449650篇
综合类   64925篇
现状与发展   12篇
一般理论   1162篇
预防医学   236409篇
眼科学   70088篇
药学   221776篇
  13篇
中国医学   5876篇
肿瘤学   160568篇
  2019年   24056篇
  2018年   33377篇
  2017年   25317篇
  2016年   28495篇
  2015年   32051篇
  2014年   45161篇
  2013年   68250篇
  2012年   93001篇
  2011年   98961篇
  2010年   59040篇
  2009年   55678篇
  2008年   92925篇
  2007年   98910篇
  2006年   99904篇
  2005年   96822篇
  2004年   93044篇
  2003年   89565篇
  2002年   86726篇
  2001年   135736篇
  2000年   139310篇
  1999年   117243篇
  1998年   34134篇
  1997年   30148篇
  1996年   30374篇
  1995年   28883篇
  1994年   26651篇
  1993年   25114篇
  1992年   91674篇
  1991年   89607篇
  1990年   87636篇
  1989年   84423篇
  1988年   77483篇
  1987年   76485篇
  1986年   71627篇
  1985年   68890篇
  1984年   51478篇
  1983年   43712篇
  1982年   26158篇
  1979年   47470篇
  1978年   34059篇
  1977年   28452篇
  1976年   27255篇
  1975年   29055篇
  1974年   35052篇
  1973年   33395篇
  1972年   31205篇
  1971年   29526篇
  1970年   27202篇
  1969年   25850篇
  1968年   23773篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
Metabolic syndrome is associated with increased risk for cardiovascular and cerebrovascular disease. The World Health Organization and National Cholesterol Education Program Adult Treatment Panel III have identified physiologic abnormalities associated with metabolic syndrome, including impaired glucose metabolism, high blood pressure, elevated cholesterol levels, and abdominal obesity. It is estimated that 47 million Americans have metabolic syndrome. A variety of therapies may help reduce the incidence and risk, including diet, weight loss, physical exercise, glycemic control, and pharmacological treatments. Nursing care is focused on developing an individualized plan of care that includes family members and providing education, psychosocial support, close monitoring, and continued follow-up to ensure adherence and success in achieving patient outcomes.  相似文献   
972.
973.
The purpose of this study was to provide, in a large number of patients, comprehensive Doppler echocardiographic assessment of normal St Jude Medical mitral valve prosthesis function using Doppler-derived hemodynamic variables, including the mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio and prosthesis performance index. The pressure half-time was less than 130 milliseconds in all patients, and all but one patient had either a peak early mitral diastolic velocity of 2 m/s or less or a mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio of less than 2.2. There was a significant (P < .001) negative correlation between the prosthesis performance index and prosthesis size. This negative correlation suggests that there is more efficient use of the in vitro geometric orifice area with smaller prostheses.  相似文献   
974.
975.
976.
977.
The use of autologous blood transfusion in cardiac surgery is still controversial. This study was prospectively designed to evaluate the haemodynamic and haematological benefits of this method, with special attention to its impact on reducing bank blood requirements. Between November 1983 and October 1984, 160 patients underwent cardiac surgery with extracorporeal circulation and were randomly assigned to two groups: group I (81 patients) was the control group and group II (79 patients) received autologous transfusion following extracorporeal circulation. Blood was withdrawn immediately after the induction of anaesthesia via a jugular catheter and stored in CPD solution at room temperature. The volume of blood removed was replaced with gelatin solutions; after bypass, blood was returned to the patient. There was no difference in systolic, diastolic or mean blood pressures between the two groups. Right atrial pressure and heart rate were not statistically different in both groups. Myocardial perfusion and myocardial oxygen consumption remained unchanged in group II compared with group I. Complete haematological evaluation was carried out before and during bypass, and thereafter daily for the first twelve days of the postoperative period. There was no significative difference between the two groups in platelet counts, fibrinogen levels, prothrombin and partial thromboplastin times. During extracorporeal circulation, mean haematocrit was 22.9 +/- 0.4% in group II and 25.3 +/- 0.5% in group I (p less than 10(-3)). The mean haematocrit time course was similar in both groups during the postoperative period and returned to preoperative value at discharge.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
978.
979.
980.
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