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   420篇
  免费   13篇
  国内免费   75篇
儿科学   29篇
妇产科学   1篇
基础医学   25篇
口腔科学   6篇
临床医学   81篇
内科学   84篇
皮肤病学   16篇
神经病学   10篇
特种医学   93篇
外科学   16篇
综合类   25篇
预防医学   14篇
眼科学   5篇
药学   50篇
  1篇
中国医学   1篇
肿瘤学   51篇
  2023年   2篇
  2021年   3篇
  2020年   3篇
  2019年   2篇
  2018年   2篇
  2017年   3篇
  2016年   4篇
  2015年   9篇
  2014年   10篇
  2013年   8篇
  2012年   3篇
  2011年   5篇
  2010年   5篇
  2009年   11篇
  2008年   2篇
  2007年   54篇
  2006年   8篇
  2005年   13篇
  2004年   2篇
  2003年   2篇
  2001年   4篇
  2000年   13篇
  1999年   7篇
  1998年   22篇
  1997年   32篇
  1996年   30篇
  1995年   25篇
  1994年   18篇
  1993年   15篇
  1992年   9篇
  1991年   9篇
  1990年   7篇
  1989年   12篇
  1988年   17篇
  1987年   14篇
  1986年   16篇
  1985年   15篇
  1984年   9篇
  1983年   6篇
  1982年   16篇
  1981年   13篇
  1980年   9篇
  1979年   4篇
  1978年   6篇
  1977年   5篇
  1976年   8篇
  1975年   8篇
  1971年   2篇
  1964年   1篇
  1950年   1篇
排序方式: 共有508条查询结果,搜索用时 0 毫秒
501.
Sekhsaria  S; Malech  HL 《Blood》1993,81(8):2125-2130
Peripheral blood hematopoietic progenitors (PBHP) are capable of colony growth in vitro. The effect of stem cell factor (SCF), interleukin-6 (IL-6), and basic fibroblast growth factor (bFGF) on myeloid colony proliferation of PBHP was determined. PBHP purified by positive selection with CD34-specific antibody were plated in semisolid agarose with reported plateau doses of interleukin-3 (IL-3), granulocyte- macrophage colony-stimulating factor (GM-CSF), and granulocyte colony- stimulating factor (G-CSF) to enhance myeloid colony growth. Experiments then were done to examine colony growth in response to SCF or with SCF and bFGF and/or IL6. SCF alone in the absence of any other growth factors did not support colony growth. SCF at a determined optimum concentration of 100 ng/mL added to the combination of IL-3, GM- CSF, and G-CSF enhanced colony growth and size relative to proliferation in response to the latter three factors alone (from 78 to 188 total colonies/10(4) PBHP plated and from 10 to 93 large [> 200 cells] colonies/10(4) PBHP plated). Furthermore, addition of bFGF and/or IL-6 to the combination of optimum concentrations of SCF, IL-3, GM-CSF, and G-CSF further enhanced colony number and size in a dose- dependent fashion. Using the optimum combination of all growth factors, we determined that the number of myeloid colony-forming PBHP in whole blood was similar between individuals at about three colonies per milliliter whole blood. We conclude that progenitors capable of responding to the early-acting growth factor, SCF, are represented in PBHP and that the number of circulating myeloid colony-forming PBHP is likely a regulated parameter that may have an important biologic function.  相似文献   
502.
503.
Endometriosis detection by US with laparoscopic correlation   总被引:1,自引:0,他引:1  
Endometriosis is a common cause of female infertility. It may affect as many as 40% of infertile women and may be the sole contributing factor to infertility in 15%. A study was undertaken to determine the usefulness of the routine pelvic ultrasound (US) examination in the detection of endometriosis by correlating pelvic US findings with laparoscopic findings in 85 patients who underwent both examinations. Forty-eight patients (56.5%) had no laparoscopic evidence of endometriosis, and 37 patients (43.6%) had endometriosis. Eight of the patients had abnormal sonograms; of these patients, only four had sonographic abnormalities that corresponded to laparoscopically identified endometriosis. Thus, US was successful in detecting endometriosis in only four (10.8%) of 37 patients. US is neither sensitive nor specific in diagnosing endometriosis. Furthermore, we believe that US does not have a significant role in the diagnosis or management of endometriosis in patients in whom a pelvic mass or other obvious pelvic abnormality is not suspected.  相似文献   
504.
In 261 infants with vomiting, 11 duodenal abnormalities were diagnosed with fluid-aided ultrasound (US). These abnormalities included duodenal obstruction, malrotation with and without associated volvulus, incomplete rotation, and duodenal stenosis. US was the initial modality used in the evaluation of vomiting in these neonates and young infants. The overall sensitivity and specificity of fluid-aided US evaluation of duodenal abnormalities were 100% and 99%, respectively. (Workup bias limits the reliability of these figures.) Fluid-aided US examination of the stomach and duodenum provided a dynamic view of duodenal rotation and anatomy, and at the very least provided a method of triaging those infants who may require surgery, upper gastrointestinal series, or follow-up US to make a definitive diagnosis.  相似文献   
505.
Mafee  MF; Aimi  K; Kahen  HL; Valvassori  GE; Capek  V 《Radiology》1986,160(1):193-200
Inflammation of the middle ear cleft is a disease of great interest from both clinical and radiologic points of view. The attic floor (tympanic diaphragm), the tympanic isthmus, and the aditus ad antrum play important roles in inflammatory processes of the middle ear cleft. The anatomy of the temporal bone at this level was examined by studying microdissections of 250 fresh temporal bones and reviewing over 1,000 high-resolution computed tomography (CT) scans of the temporal bones. The pertinent anatomy is described, and the role of the tympanic diaphragm and isthmus in determining the degree to which middle ear disease may progress is stressed. The appearances on CT scans of chronic otomastoiditis, tympanosclerosis, cholesterol granuloma, attic retraction pocket, and acquired cholesteatoma are reviewed and illustrated.  相似文献   
506.
Fetal choroid plexus cysts: beware the smaller cyst   总被引:1,自引:0,他引:1  
  相似文献   
507.
王慧玲  奚耕思 《医学争鸣》1999,20(10):S076-S077
精胺广泛存在于动物组织和体液中,它在生殖过程中的作用还存在着很大的争议,作者综述了这些研究成果,并对其今后的发展动态作了展望.  相似文献   
508.
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