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   1540篇
  免费   90篇
  国内免费   9篇
耳鼻咽喉   14篇
儿科学   74篇
妇产科学   147篇
基础医学   163篇
口腔科学   25篇
临床医学   156篇
内科学   344篇
皮肤病学   25篇
神经病学   28篇
特种医学   143篇
外科学   181篇
综合类   22篇
一般理论   1篇
预防医学   130篇
眼科学   11篇
药学   59篇
  1篇
中国医学   6篇
肿瘤学   109篇
  2023年   8篇
  2022年   14篇
  2021年   26篇
  2019年   21篇
  2018年   24篇
  2017年   13篇
  2016年   19篇
  2015年   25篇
  2014年   33篇
  2013年   57篇
  2012年   57篇
  2011年   62篇
  2010年   50篇
  2009年   51篇
  2008年   66篇
  2007年   61篇
  2006年   52篇
  2005年   39篇
  2004年   45篇
  2003年   41篇
  2002年   38篇
  2001年   37篇
  2000年   38篇
  1999年   35篇
  1998年   32篇
  1997年   33篇
  1996年   51篇
  1995年   46篇
  1994年   43篇
  1993年   28篇
  1992年   27篇
  1991年   40篇
  1990年   31篇
  1989年   38篇
  1988年   48篇
  1987年   42篇
  1986年   45篇
  1985年   36篇
  1984年   30篇
  1983年   21篇
  1982年   9篇
  1981年   12篇
  1980年   12篇
  1979年   12篇
  1977年   10篇
  1976年   8篇
  1974年   10篇
  1972年   10篇
  1970年   8篇
  1966年   6篇
排序方式: 共有1639条查询结果,搜索用时 15 毫秒
101.
Interobserver variation in the interpretation of abdominal radiographs   总被引:2,自引:0,他引:2  
A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern.  相似文献   
102.
Diabetic embryopathy: pathogenesis, prenatal diagnosis and prevention   总被引:1,自引:0,他引:1  
In spite of the overall improvement in the management of diabetic pregnancies, congenital anomalies among infants of diabetic mothers still remain two to three times higher than in the nondiabetic population. Approximately 40 per cent of all perinatal deaths among diabetic offspring are due to congenital malformations. This article reviews the subject and discusses current views on pathogenesis, based on human and experimental work, describes methods available for prenatal diagnosis, and suggests an approach to the possible prevention of these malformations.  相似文献   
103.
104.
105.
A prospective longitudinal study was conducted in order to determine by sonographically estimated fetal weight the patterns of fetal growth in twins. Thirty-five healthy women with normal twin pregnancies were examined every three weeks from the 15th week of gestation to delivery. Among the measurements obtained were the biparietal diameter (BPD), the abdominal circumference, and the calculated fetal weight. From 15-28 weeks, the growth velocity of the BPD and abdominal circumference remained fairly constant, with a steady increase in incremental growth. Beyond this age, we observed a slowing in growth of the BPD, while the abdominal circumference continued at a constant rate. The growth velocity of the weight steadily increased throughout pregnancy. Although greater biologic variability in weight between twin A and B was observed as gestational age progressed, the overall mean weights of twin A and B were not statistically different. We have generated a nomogram of fetal weight gain throughout pregnancy.  相似文献   
106.
There is increasing interest in the use of implantable naltrexone as a new treatment for opiate dependence. This center has been one of the leaders in this form of treatment in Australia and has recently completed a registry-controlled review of our mortality data. As part of the study of the safety profile of this therapy, we were interested to review both the treatment correlates of previously presented mortality data and of adverse events. A total of 255 naltrexone implant therapy (NIT) and 2,518 buprenorphine (BUP) patients were followed for 1,322.22 and 8,030.02 patient-years, respectively. NIT patients had significantly longer days in treatment per episode (mean ± standard deviation, 238.32 ± 110.11 vs. 46.96 ± 109.79), total treatment duration (371.21 ± 284.64 vs. 162.50 ± 245.76), and mean treatment times but fewer treatment episodes than BUP (all p < .0001). Serious local tissue reaction or infection each occurred in 1% of 200 NIT episodes. These data show that NIT economizes treatment resources without compromising safety concerns.  相似文献   
107.
108.
109.
Philadelphia (Ph1) chromosome-positive clonogenic progenitors usually disappear within 4 to 6 weeks in long-term cultures established from the marrow of patients with chronic myeloid leukemia (CML). In contrast, coexisting chromosomally normal hematopoietic cells are relatively well maintained. Thus, even though normal cells are initially undetectable, they may become the predominant population. Recently, we have begun to explore the potential of such cultures as a strategy for preparing CML marrow for autografting, and based on cytogenetic studies of the differential kinetics of Ph1-positive and Ph1-negative clonogenic cells, have chosen a 10-day period in culture to obtain maximal numbers of selectively enriched normal stem cells. Here we present the results of molecular analyses of the cells regenerated in vivo for the initial three CML patients to be treated using this approach by comparison with the differentiated cells generated by continued maintenance of an aliquot of the autograft in vitro (using a slightly modified culture feeding procedure to enhance the production and release of cells into the nonadherent fraction after 4 weeks) for the one patient whose genotype made molecular analysis of clonality status also possible. These analyses showed that cells with a rearranged breakpoint cluster region (BCR) gene were not detectable by Southern blotting in either in vitro or in vivo populations of mature cells that might be assumed to represent the progeny of primitive cells present at the end of the initial 10 days in culture. Production of BCR-negative cells was also shown to be temporally correlated with the appearance of nonclonal hematopoietic cells both in culture and in vivo. These findings provide support for the view that prolonged maintenance of CML marrow cells in long-term culture may allow molecular characterization of both the BCR-genotype and clonality status of cells with in vivo regenerative potential.  相似文献   
110.
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