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   1030篇
  免费   73篇
  国内免费   28篇
儿科学   61篇
妇产科学   14篇
基础医学   88篇
口腔科学   49篇
临床医学   170篇
内科学   242篇
皮肤病学   13篇
神经病学   23篇
特种医学   259篇
外科学   62篇
综合类   22篇
预防医学   35篇
眼科学   4篇
药学   49篇
肿瘤学   40篇
  2022年   3篇
  2021年   5篇
  2020年   3篇
  2019年   12篇
  2018年   22篇
  2017年   13篇
  2016年   11篇
  2015年   15篇
  2014年   22篇
  2013年   19篇
  2012年   24篇
  2011年   26篇
  2010年   38篇
  2009年   31篇
  2008年   19篇
  2007年   32篇
  2006年   34篇
  2005年   25篇
  2004年   20篇
  2003年   30篇
  2002年   23篇
  2001年   18篇
  2000年   15篇
  1999年   15篇
  1998年   60篇
  1997年   71篇
  1996年   79篇
  1995年   47篇
  1994年   39篇
  1993年   44篇
  1992年   19篇
  1991年   12篇
  1990年   20篇
  1989年   39篇
  1988年   41篇
  1987年   30篇
  1986年   30篇
  1985年   31篇
  1984年   8篇
  1983年   11篇
  1982年   13篇
  1981年   10篇
  1980年   12篇
  1979年   3篇
  1978年   4篇
  1977年   13篇
  1976年   10篇
  1975年   6篇
  1966年   1篇
  1950年   1篇
排序方式: 共有1131条查询结果,搜索用时 15 毫秒
11.
12.
Oscillatory motion of the normal cervical spinal cord   总被引:2,自引:0,他引:2  
  相似文献   
13.
Periosteal Ewing sarcoma   总被引:3,自引:0,他引:3  
  相似文献   
14.
15.
In a prospective, randomized study of insemination with donor semen, intracervical insemination by straw was compared with insemination using a cervical cap with an intracervical reservoir. A total of 91 patients completed 486 treatment cycles. There were no significant differences in age, parity, indication for insemination by donor, or method of cycle monitoring between women who became pregnant and those who did not conceive with either insemination method. In 236 standard intracervical insemination cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude pregnancy rates and the cumulative pregnancy rates calculated by the Kaplan-Meier life-table method were significantly different (chi(2)-test, P < 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates in artificial insemination with cryopreserved donor semen may be improved by the use of a cervical cap when compared to cervical insemination by straw. The use of the cervical cap may prolong the exposure of the spermatozoa to the cervical mucus and prevent the backflow of semen into the vagina.   相似文献   
16.
17.
Dumas  JM; Edde  DJ 《Radiology》1986,160(2):453-456
In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed.  相似文献   
18.
19.
A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties.  相似文献   
20.
Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.   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