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   515214篇
  免费   33337篇
  国内免费   615篇
耳鼻咽喉   6905篇
儿科学   16866篇
妇产科学   13545篇
基础医学   85189篇
口腔科学   14475篇
临床医学   44448篇
内科学   93833篇
皮肤病学   12160篇
神经病学   36327篇
特种医学   18482篇
外国民族医学   63篇
外科学   77251篇
综合类   8482篇
一般理论   119篇
预防医学   39021篇
眼科学   12152篇
药学   40591篇
中国医学   1007篇
肿瘤学   28250篇
  2018年   4957篇
  2015年   4543篇
  2014年   6097篇
  2013年   9591篇
  2012年   12928篇
  2011年   14335篇
  2010年   8334篇
  2009年   7799篇
  2008年   13747篇
  2007年   14766篇
  2006年   14999篇
  2005年   14418篇
  2004年   14097篇
  2003年   13435篇
  2002年   13318篇
  2001年   24111篇
  2000年   25108篇
  1999年   20577篇
  1998年   5441篇
  1997年   4719篇
  1996年   5053篇
  1995年   4638篇
  1994年   4329篇
  1993年   4148篇
  1992年   15745篇
  1991年   16327篇
  1990年   16436篇
  1989年   15816篇
  1988年   14589篇
  1987年   14436篇
  1986年   13608篇
  1985年   12996篇
  1984年   9640篇
  1983年   8254篇
  1982年   4564篇
  1981年   4232篇
  1979年   9424篇
  1978年   6863篇
  1977年   5783篇
  1976年   5609篇
  1975年   6402篇
  1974年   7635篇
  1973年   7135篇
  1972年   6963篇
  1971年   6686篇
  1970年   6173篇
  1969年   5889篇
  1968年   5560篇
  1967年   5012篇
  1966年   4450篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
This paper examines the effect of patient age, tumour grade and extent of surgery on the outcome of treatment of 278 patients with high grade malignant gliomas referred to the Queensland Radium Institute between 1980 and 1987. The aim was to determine whether the extent of surgical resection alters survival rates. The extent of surgery had no effect on survival except for those patients with grade 3 tumours in whom a total excision was possible. Those in whom only a biopsy was done did not have a worse prognosis. Grading was found to be of importance, as patients with grade 3 tumours had a better survival than those with grade 4 tumours. In grade 4 tumours, those under 30 years of age had a better survival than those over 30 years, whereas with grade 3 tumours there was a gradation of age effect (under 40 years best, then 40–49 years, and those 50 years and over doing worst).  相似文献   
102.
103.
104.
105.
106.
Three hundred and twenty samples of subgingival plaque were obtained from 80 caucasian girls, ranging from 10 to 13 years of age. The samples were analyzed to verify the influence of age upon colonization of the gingival sulcus by microorganisms potentially pathogenic to the periodontal tissues. The gingival and plaque status were evaluated through the gingival index (GI) and plaque index (PlI) and the microflora was assessed by the enzymatic method benzoyl-arginine-naphthylamide (BANA). The results of the BANA test were positive for 62.50% of the tested individuals and 40% of the examined sites. The influence of age was statistically significant on BANA reactivity, and the number of positive sites was greater at 11 (57.5%) than at 12 years (28.8%).  相似文献   
107.
108.
109.
Variations of the medial and inferior choanal limits may facilitate snoring. These are: 1) short vomer without crista choanalis vomeris and adaptational formations, 2) extremely concave posterior margin of the hard palate leading to disproportion between the muscular and aponeurotic part of m. tensor veli palatini and hence to a flabby soft palate especially during sleep, and 3) neonatal relation of the height and width of the choane resulting in a very large choanal region instead of relative reduction of choanal width compared to its increasing height. All these variations result in a flabby soft palate especially during sleep and may lead to formation of whirles of inspired air and snoring.  相似文献   
110.
Most authors consider the principal advantage of FG anastomoses (compared to microsurgical anastomoses) to be shorter operating time, reduced surgical trauma to oviduct stumps, and absence of tissue ischemia. These features promote reparative regeneration and decrease adhesion formation, resulting in complete recanalization of fallopian tubes. To date, the majority of work on FG is confined to the experimental development of surgical techniques. Investigations in reconstructive gynecological surgery are quite uncommon. The physical properties of FG and the positive results of available experimental studies suggest that further development of surgical techniques using FG in obstetrics and gynecology is worthwhile.  相似文献   
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