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   816篇
  免费   43篇
  国内免费   59篇
儿科学   43篇
妇产科学   22篇
基础医学   40篇
口腔科学   13篇
临床医学   157篇
内科学   227篇
皮肤病学   17篇
神经病学   13篇
特种医学   229篇
外科学   33篇
综合类   27篇
预防医学   27篇
眼科学   17篇
药学   31篇
中国医学   2篇
肿瘤学   20篇
  2022年   3篇
  2021年   9篇
  2020年   4篇
  2019年   3篇
  2018年   13篇
  2017年   4篇
  2016年   1篇
  2015年   14篇
  2014年   14篇
  2013年   27篇
  2012年   10篇
  2011年   10篇
  2010年   20篇
  2009年   21篇
  2008年   13篇
  2007年   47篇
  2006年   7篇
  2005年   15篇
  2004年   16篇
  2003年   10篇
  2002年   14篇
  2001年   13篇
  2000年   12篇
  1999年   14篇
  1998年   51篇
  1997年   36篇
  1996年   59篇
  1995年   45篇
  1994年   40篇
  1993年   49篇
  1992年   10篇
  1991年   12篇
  1990年   18篇
  1989年   27篇
  1988年   33篇
  1987年   35篇
  1986年   29篇
  1985年   29篇
  1984年   16篇
  1983年   12篇
  1982年   12篇
  1981年   22篇
  1980年   19篇
  1979年   6篇
  1978年   9篇
  1977年   15篇
  1976年   7篇
  1975年   9篇
  1970年   2篇
  1963年   1篇
排序方式: 共有918条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
We investigated the use of three monoclonal antikeratin antibodies on routinely formalin-fixed and paraffin-embedded punch and cone biopsies of the normal human uterine cervix and its metaplastic and premalignant lesions. Monoclonal antibodies used were AE8, which is specific for keratin 13; 34BE12, which reacts with keratins of the stratified squamous epithelium; and CAM5.2, which is specific for keratin 8. All these antibodies performed well in routinely processed surgical pathology material. AE8 antibody stained the suprabasal layer of the normal squamous epithelium. Squamous metaplasia and dysplasia were stained in 50% of the cases. Normal suprabasal distribution of the keratin 13, however, was lost in all positive dysplasia cases. CAM5.2 reacted with normal columnar cells in all cases, and squamous metaplasia was focally positive in 20% of the cases. Dysplasia showed a positive reaction in 30% to 40% of the cases. The 34BE12 antibody was reacting with the full thickness of the squamous epithelium. Squamous metaplasia and dysplasia were positive in 80% of the cases. In addition, 34BE12 stained reserve cell hyperplasia, making it a useful marker for this condition. Our results demonstrate that keratin immunohistochemistry with the above-listed antibodies gives pathogenetically interesting information on cervical lesions.  相似文献   
6.
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.  相似文献   
7.
Goei  R; Baeten  C; Arends  JW 《Radiology》1988,168(2):303-306
Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis.  相似文献   
8.
9.
10.
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