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   8925篇
  免费   872篇
  国内免费   25篇
耳鼻咽喉   211篇
儿科学   222篇
妇产科学   382篇
基础医学   879篇
口腔科学   182篇
临床医学   834篇
内科学   1912篇
皮肤病学   220篇
神经病学   747篇
特种医学   620篇
外国民族医学   2篇
外科学   1442篇
综合类   146篇
一般理论   3篇
预防医学   683篇
眼科学   267篇
药学   350篇
  1篇
中国医学   4篇
肿瘤学   715篇
  2021年   78篇
  2019年   98篇
  2018年   115篇
  2017年   96篇
  2016年   118篇
  2015年   126篇
  2014年   172篇
  2013年   235篇
  2012年   332篇
  2011年   357篇
  2010年   207篇
  2009年   175篇
  2008年   299篇
  2007年   350篇
  2006年   374篇
  2005年   343篇
  2004年   320篇
  2003年   341篇
  2002年   290篇
  2001年   268篇
  2000年   315篇
  1999年   280篇
  1998年   120篇
  1997年   103篇
  1996年   90篇
  1995年   96篇
  1994年   88篇
  1993年   101篇
  1992年   217篇
  1991年   228篇
  1990年   234篇
  1989年   216篇
  1988年   202篇
  1987年   211篇
  1986年   217篇
  1985年   216篇
  1984年   143篇
  1983年   142篇
  1982年   97篇
  1981年   95篇
  1980年   87篇
  1979年   154篇
  1978年   112篇
  1977年   113篇
  1976年   95篇
  1975年   107篇
  1974年   129篇
  1973年   109篇
  1972年   97篇
  1971年   75篇
排序方式: 共有9822条查询结果,搜索用时 15 毫秒
61.
SUMMARY In order to assess the reliability of drug information supplied by day-stay cases, 85 consecutive patients were interviewed. A comparison of the interview answers with the details previously volunteered during the admission procedure showed an increase of 80% in the information given by the patient. While the detailed interviewing technique is time-consuming and may not be infallible, this substantial increase in information highlights problems in the current routine.  相似文献   
62.
Independent experiments have been performed at two centers, to evaluate the dosimetric properties of their respective 109Cd K X-ray fluorescence (XRF) bone lead measurement systems. Measurements were made of the dose to several points on the skin on the lower leg, at the surface of the tibia, in the red marrow tibia cavity, at the midcalf, and in the abdominal region occupied by the conceptus. Overall agreement between the two data sets was found. Similarities and differences are discussed. The effective dose values for an in vivo measurement of tibia lead concentration in 1-, 5-, and 10-year-old and adult subjects were calculated from one data set to be 1100, 420, 190, and 34/38 (male/female) nSv, respectively, for an in vivo median precision (one standard deviation) of 4.9 micrograms Pb (g bone mineral)-1 for a 30-min adult measurement.  相似文献   
63.
64.
Indomethacin has been used in twins with polyhydramnios to decrease amniotic fluid volume. Under therapy, a marked reduction of both fetuses' urine production has been demonstrated within 24 hours concomitant with maternal symptomatic relief. Discontinuation of therapy was associated with a rapid increase in fetal urine production. The clinical observation indicates that the benefit of indomethacin in prolonging such pregnancies is most probably the result of relief of polyhydramnios through decreased fetal urine production.  相似文献   
65.
66.
STUDY OBJECTIVE--Ischaemic heart disease is known to contribute to the development of ventricular arrhythmias. However, the role of non-ischaemic variables has been less well defined. We therefore studied the effect of myocardial stretch and ventricular mass on the vulnerability of the rat heart to ventricular fibrillation. DESIGN AND EXPERIMENTAL MATERIAL--Two groups of rat hearts were studied in an isolated buffer perfused apparatus: group I, mature female animals with an average dry left ventricular weight of 73 mg and group II, a group of retired breeders with an average left ventricular weight of 122 mg. Hearts performed isovolumetric work at either low (0 mm Hg) or high (20 mm Hg) left ventricular end diastolic pressures. MEASUREMENTS AND MAIN RESULTS--Ventricular fibrillation was provoked by trains of ventricular extrastimuli delivered at increasing current until development of the arrhythmia. The current required to provoke ventricular fibrillation decreased in both groups at the high left ventricular end diastolic pressure and the larger hearts in group II were more vulnerable to ventricular fibrillation than those in group I. The decrease in ventricular fibrillation threshold occurred in the absence of an increase in myocardial lactate production or a decrease in endocardial to epicardial flow ratios. CONCLUSIONS--This study thus identified two variables, myocardial stretch and ventricular mass, which influence the development of ventricular fibrillation and which are independent of myocardial ischaemia in this animal model. These observations may be relevant to an understanding of the increased incidence of lethal arrhythmias which occur in patients with dilated cardiomyopathies.  相似文献   
67.
68.
69.
Liver and intestine transplantation   总被引:1,自引:0,他引:1  
The most significant development in liver transplantation in the USA over the past year was the full implementation of the MELD- and PELD-based allocation policy in March 2002, which shifted emphasis from waiting time within broad medical urgency status to prioritization by risk of waiting list death. The implementation of this system has led to a decrease in pretransplant mortality without increasing post-transplant mortality, despite a higher severity of illness at the time of transplant.
The trend over the last few years of rapidly increasing numbers of adult living donor liver transplants was reversed in 2002 by a decline of more than 30% in the number of these procedures. In 2002, a greater percentage of women received livers from living donors (43%) than deceased donors (34%), possibly because of size considerations.
From 1993 to 2001, the waiting list increased more than sixfold, from 2902 patients to 18 047 patients. For the first time since 1993, the waiting list size decreased in 2002, dropping 6% to 16 974 candidates. The percentage of temporarily inactive liver candidates also increased from 2001, thus the net decrease in the active waiting list for 2002 was 12%. This may reflect a trend toward less pre-emptive listing practices under MELD.
Intestine transplantation remains a low-volume procedure limited to a few transplant centers and is still accompanied by significant pre- and post-transplantation risks. As this procedure matures, its application may increase to include recipients at an earlier stage of their disease with better likelihood of success.  相似文献   
70.
M. Rosen 《Surgical endoscopy》2003,17(10):1685-1685
  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