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   401篇
  免费   22篇
  国内免费   12篇
耳鼻咽喉   1篇
儿科学   13篇
妇产科学   5篇
基础医学   41篇
口腔科学   24篇
临床医学   53篇
内科学   114篇
皮肤病学   5篇
神经病学   6篇
特种医学   74篇
外科学   20篇
综合类   18篇
预防医学   18篇
眼科学   1篇
药学   28篇
中国医学   1篇
肿瘤学   13篇
  2023年   4篇
  2022年   4篇
  2021年   4篇
  2020年   5篇
  2019年   6篇
  2018年   7篇
  2017年   4篇
  2016年   11篇
  2015年   5篇
  2014年   8篇
  2013年   16篇
  2012年   5篇
  2011年   7篇
  2010年   17篇
  2009年   24篇
  2008年   5篇
  2007年   19篇
  2006年   5篇
  2005年   2篇
  2004年   6篇
  2003年   5篇
  2002年   2篇
  2001年   7篇
  2000年   3篇
  1999年   5篇
  1998年   30篇
  1997年   30篇
  1996年   30篇
  1995年   25篇
  1994年   17篇
  1993年   19篇
  1992年   7篇
  1991年   3篇
  1990年   11篇
  1989年   12篇
  1988年   14篇
  1987年   18篇
  1986年   6篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
  1977年   5篇
  1976年   3篇
  1975年   3篇
排序方式: 共有435条查询结果,搜索用时 15 毫秒
61.
Magnetization transfer contrast: MR imaging of the knee   总被引:1,自引:0,他引:1  
  相似文献   
62.
63.
64.
Renal localization of gallium-67 citrate   总被引:1,自引:0,他引:1  
  相似文献   
65.
The purpose of this study was to investigate any influence of maternal and/or paternal age on gamete characteristics and pregnancy outcomes in intracytoplasmic sperm injection (ICSI) cycles. In all, 821 consecutive ICSI cases were analysed retrospectively. While a significant linear decline in semen volume was detected, no significant differences in the concentration, motility or morphology of the spermatozoa were found with paternal ageing. A significant decline in the number of oocytes retrieved and the number of mature oocytes obtained was found with advancing maternal age. An increase in the occurrence of digyny was noted with parental ageing, while no difference in single or bipronuclear fertilization was found. Older women had a decreased incidence of single pronucleus formation and an increase in digyny, but no significant difference in the percentage of oocytes that underwent two-pronuclear fertilization was detected with regard to maternal ageing. Pregnancy outcomes were not influenced by the age of the male partner, while a strong negative correlation was found with maternal ageing. To better analyse male partner ageing as a factor affecting pregnancy outcome, we analysed a subgroup of patients with a female partner aged <35 years who underwent ICSI. No paternal influence on ICSI pregnancy outcome was found in this subgroup of patients. We conclude that the influence on pregnancy outcome after ICSI is related mostly to maternal and not paternal age.   相似文献   
66.
The false falx sign   总被引:5,自引:0,他引:5  
Osborn  AG; Anderson  RE; Wing  SD 《Radiology》1980,134(2):421
  相似文献   
67.
Bone sarcomas in Paget disease: a study of 85 patients   总被引:5,自引:0,他引:5  
Smith  J; Botet  JF; Yeh  SD 《Radiology》1984,152(3):583-590
This is a comprehensive review of 85 patients who had bone sarcoma associated with Paget disease and who were seen at Memorial Sloan-Kettering Cancer Center between 1927 and 1982. There was an almost equal distribution of tumors in the axial and the appendicular skeletons. The pelvis, humerus, femur, and skull were the tumor sites in 80% of cases. The tumors were bulky large soft tissue masses. Lytic lesions were more common than sclerotic lesions. Mixed lytic and sclerotic lesions were much less common than either single type. Periosteal reaction was uncommon and found in less than 7%. Methylene diphosphonate scans of the bone often showed a cold area that was associated with marked increase in uptake on the gallium scan. Angiography, which was performed in 13 patients, was useful, but CT was much more helpful in showing the soft tissue mass as well as the extent of bony disease. Only three patients in this study survived for five years. Present chemotherapy protocols were disappointing in the treatment of this highly lethal tumor.  相似文献   
68.
69.
Use of a radioimmunoassay to quantify thrombospondin   总被引:8,自引:0,他引:8  
Saglio  SD; Slayter  HS 《Blood》1982,59(1):162-166
Results of radioimmunoassay procedures applied to samples containing thrombospondin indicated that reliable values are obtained either in saline or in plasma. Plasma levels in apparently normal individuals ranged from approximately 20 to 300 ng/ml. The mean for 20 individuals was 175 ng/ml. Plasma specimens stored either refrigerated at 4 degrees C or frozen at -80 degrees C showed significantly diminished thrombospondin levels over a period of 90 days. Serum levels of thrombospondin were found to range from 10,000 to 30,000 ng/ml.  相似文献   
70.
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