全文获取类型
收费全文 | 1540篇 |
免费 | 90篇 |
国内免费 | 9篇 |
专业分类
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 |
出版年
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.
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.
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.
Estimated fetal weight in the evaluation of growth in twin gestations: a prospective longitudinal study 总被引:1,自引:0,他引:1
S Yarkoni E A Reece T Holford T Z O'Connor J C Hobbins 《Obstetrics and gynecology》1987,69(4):636-639
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.
Albert Stuart Reece M.B.B.S. F.R.A.C.G.P. F.R.C.S. F.R.C.S. M.D. 《Journal of substance abuse treatment》2009,37(3):256-265
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.
A G Turhan R K Humphries C J Eaves M J Barnett G L Phillips D K Kalousek H G Klingemann P L Lansdorp D E Reece J D Shepherd 《Blood》1990,76(11):2404-2410
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.