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   1479篇
  免费   91篇
  国内免费   60篇
耳鼻咽喉   9篇
儿科学   56篇
妇产科学   12篇
基础医学   184篇
口腔科学   25篇
临床医学   233篇
内科学   422篇
皮肤病学   22篇
神经病学   80篇
特种医学   253篇
外科学   107篇
综合类   29篇
预防医学   56篇
眼科学   14篇
药学   73篇
中国医学   3篇
肿瘤学   52篇
  2021年   25篇
  2020年   8篇
  2019年   10篇
  2018年   19篇
  2017年   15篇
  2016年   12篇
  2015年   28篇
  2014年   30篇
  2013年   46篇
  2012年   34篇
  2011年   41篇
  2010年   40篇
  2009年   36篇
  2008年   40篇
  2007年   85篇
  2006年   38篇
  2005年   48篇
  2004年   41篇
  2003年   43篇
  2002年   30篇
  2001年   23篇
  2000年   24篇
  1999年   29篇
  1998年   61篇
  1997年   44篇
  1996年   71篇
  1995年   49篇
  1994年   47篇
  1993年   52篇
  1992年   18篇
  1991年   21篇
  1990年   34篇
  1989年   36篇
  1988年   47篇
  1987年   52篇
  1986年   40篇
  1985年   50篇
  1984年   23篇
  1983年   13篇
  1982年   17篇
  1981年   26篇
  1980年   26篇
  1979年   15篇
  1978年   11篇
  1977年   19篇
  1976年   9篇
  1975年   18篇
  1974年   7篇
  1972年   12篇
  1970年   6篇
排序方式: 共有1630条查询结果,搜索用时 15 毫秒
1.
Five young children developed slowly progressive hemiparesis as the initial manifestation of Rasmussen encephalitis (RE). Three have remained seizure free over an observational period of 1.3–1.9 years. In the remaining two patients, seizures occurred after 0.5 and 0.6 years respectively. We suggest that RE might be presently underdiagnosed and should be suspected in cases of new onset hemiparesis. In this series, three out of five patients showed oligoclonal bands on examination of cerebrospinal fluid (CSF) which represented additional diagnostic hints towards an immune-mediated condition. According to recently published formal diagnostic criteria, evidence of progressive cerebral hemiatrophy or bioptic identification of RE-typical inflammation confirms the diagnosis in such cases. Long-term immunotherapy is recommended in order to prevent further tissue loss and functional decline.  相似文献   
2.
3.
4.
5.
6.
Staphylococcus aureus osteomyelitis and pyogenic arthritis has a different pattern in the elderly than in the young. The axial skeleton is the most frequent site of infection and treatment is usually by intravenous antibiotics. We report a case ofStaph. aureus septic arthritis of the elbow with concomitant osteomyelitis of the spine that was thought to be due toStaph. aureus, but culture of debrided material from the lesion grewBrucella in culture. We suggest that in the elderly it is advisable to obtain a tissue culture diagnosis and not to instigate therapy based on positive blood cultures or a concomitant infection.  相似文献   
7.
An innocuous sensory event (a prestimulus) that briefly precedes a startle-eliciting stimulus (SES) will reduce the amplitude of the subsequently elicited reflex. In three experiments brief silent periods in otherwise continuous noise (gaps) were used as prestimuli to investigate the effects of the D1 dopamine receptor agonist (±)-SKF-38393 (SKF) and the dopamine D2 receptor group agonist (−)-quinpirole hydrochloride on gap inhibition of the rat’s acoustic startle reflex. Gap durations of 4 and 50 ms were analyzed. Quinpirole (0–1.6 mg/kg) had a biphasic effect on gap inhibition. Lower doses increased gap inhibition, an effect that peaked at the 0.4 mg/kg dose. For higher doses, inhibition returned to control levels for the 4-ms long gap, but remained elevated for the 50-ms long gap. SKF had no effect on gap inhibition, and haloperidol (0.2 mg/kg) reversed the quinpirole-induced increase of gap inhibition. These data implicate the D2 dopamine receptor group in gap inhibition of startle modulation. The results are discussed in terms of the effects of catecholamine agonists on attention. Received: 25 July 1995/Final version: 28 April 1997  相似文献   
8.
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   
9.
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   
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