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   1177篇
  免费   80篇
  国内免费   22篇
耳鼻咽喉   1篇
儿科学   144篇
妇产科学   26篇
基础医学   146篇
口腔科学   14篇
临床医学   103篇
内科学   217篇
皮肤病学   14篇
神经病学   117篇
特种医学   86篇
外国民族医学   1篇
外科学   157篇
综合类   28篇
预防医学   82篇
眼科学   3篇
药学   88篇
中国医学   1篇
肿瘤学   51篇
  2023年   5篇
  2022年   6篇
  2021年   7篇
  2020年   11篇
  2019年   19篇
  2018年   20篇
  2017年   14篇
  2016年   22篇
  2015年   19篇
  2014年   25篇
  2013年   34篇
  2012年   51篇
  2011年   43篇
  2010年   27篇
  2009年   31篇
  2008年   44篇
  2007年   43篇
  2006年   57篇
  2005年   52篇
  2004年   49篇
  2003年   46篇
  2002年   43篇
  2001年   41篇
  2000年   34篇
  1999年   36篇
  1998年   26篇
  1997年   30篇
  1996年   21篇
  1995年   16篇
  1994年   18篇
  1993年   23篇
  1992年   29篇
  1991年   30篇
  1990年   33篇
  1989年   31篇
  1988年   27篇
  1987年   25篇
  1986年   22篇
  1985年   25篇
  1984年   17篇
  1983年   20篇
  1982年   13篇
  1979年   8篇
  1977年   7篇
  1975年   9篇
  1974年   6篇
  1973年   8篇
  1970年   5篇
  1969年   4篇
  1968年   6篇
排序方式: 共有1279条查询结果,搜索用时 15 毫秒
991.
Although dic(9;20)(p13.2;q11.2) is a characteristic abnormality in childhood B-cell precursor acute lymphoblastic leukemias (BCP ALL), little is known about its clinical impact or the type and frequency of additional aberrations it may occur together with. We here review the clinical and cytogenetic features of a Nordic pediatric series of 24 patients with dic(9;20)-positive BCP ALL diagnosed 1996-2006, constituting 1.3% of the BCP ALL, as well as 47 childhood cases from the literature. Consistent immunophenotypic features of the Nordic cases included positivity for HLA-DR, CD10, CD19, CD20, and CD22 and negativity for T-cell and myeloid markers; no detailed immunophenotypes were reported for the previously published cases. In the entire cohort of 71 cases, the modal chromosome distribution was 45 (62%), 46 (21%), 47 (7%), 48 (4%), 49 (3%), 44 (1%), and 50 (1%). Additional changes were present in 63%, the most frequent of which were homozygous loss of CDKN2A (33%) and gains of chromosomes 21 (28%) and X (10%). The median patient age was 3 years, the female/male ratio was 2.0, the median white blood cell count was 24 x 10(9)/l, 11% had central nervous system involvement, and 5% had a mediastinal mass at diagnosis. Risk group stratification was nonstandard risk in 79%. The event-free survival and overall survival at 5 years for the 24 Nordic cases was 0.62 and 0.82, respectively. Thus, although relapses are quite common, postrelapse treatment of many patients is successful.  相似文献   
992.
993.
994.
995.
996.
997.
To address the health needs of adolescents, health care providers need to understand adolescent perceptions of the sexual history taking process. Adolescents (n = 113) were recruited from two sources of health care to complete a questionnaire regarding sexual history taking issues. The results revealed that there were differences in demographics, practice characteristics, and communication strategies between the private office and the hospital clinic. Attitudes and beliefs related to the discussion of sensitive issues were similar. Most adolescents would like health care providers to discuss sensitive topics directly. It is important for health care providers to feel comfortable initiating discussion of sensitive issues directly.  相似文献   
998.
This longitudinal, prospective study sought to establish whether pediatric Crohn's disease (CD) and ulcerative colitis (UC) are associated with increased levels of cytogenetic damage and whether folate supplementation in combination with other treatments mitigates cytogenetic damage in children with inflammatory bowel disease (IBD). After a 1-mo treatment and folate supplementation, all clinical tests in CD (n = 24) and UC (n = 17) patients improved. Patients with CD were comparable in the cytogenetic response with controls (n = 28) assessed by micronucleus (MN) assay, but both groups differed from the UC group. While the MN frequency in epithelial cells slightly decreased from first to second observations in CD patients (p = 0.05) and controls (p = 0.11), an increase was observed in UC patients (p = 0.001). Similar changes were observed in blood lymphocytes resulting in significantly higher levels of the MNs and chromosome bridges in UC patients. These preliminary findings of a difference in chromosome damage between pediatric UC patients compared with CD patients and healthy controls warrant confirmation and expansion to determine (1) the role of cytogenetic damage in the pathogenesis of these diseases, (2) relative contribution of treatment and folate supplementation, and (3) potential links to the eventual development of cancer in some patients.  相似文献   
999.
1000.
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