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   514494篇
  免费   33369篇
  国内免费   616篇
耳鼻咽喉   6898篇
儿科学   16852篇
妇产科学   13526篇
基础医学   85065篇
口腔科学   14478篇
临床医学   44368篇
内科学   93746篇
皮肤病学   12160篇
神经病学   36252篇
特种医学   18469篇
外国民族医学   63篇
外科学   77140篇
综合类   8474篇
一般理论   118篇
预防医学   38972篇
眼科学   12136篇
药学   40591篇
中国医学   1008篇
肿瘤学   28163篇
  2018年   4946篇
  2015年   4514篇
  2014年   6064篇
  2013年   9557篇
  2012年   12902篇
  2011年   14299篇
  2010年   8319篇
  2009年   7787篇
  2008年   13720篇
  2007年   14722篇
  2006年   14967篇
  2005年   14384篇
  2004年   14079篇
  2003年   13405篇
  2002年   13287篇
  2001年   24081篇
  2000年   25099篇
  1999年   20570篇
  1998年   5428篇
  1997年   4710篇
  1996年   5042篇
  1995年   4626篇
  1994年   4318篇
  1993年   4139篇
  1992年   15732篇
  1991年   16322篇
  1990年   16441篇
  1989年   15801篇
  1988年   14583篇
  1987年   14426篇
  1986年   13604篇
  1985年   12981篇
  1984年   9631篇
  1983年   8250篇
  1982年   4562篇
  1981年   4230篇
  1979年   9419篇
  1978年   6855篇
  1977年   5773篇
  1976年   5602篇
  1975年   6396篇
  1974年   7636篇
  1973年   7132篇
  1972年   6964篇
  1971年   6690篇
  1970年   6180篇
  1969年   5890篇
  1968年   5563篇
  1967年   5015篇
  1966年   4453篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
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   
52.
53.
54.
55.
56.
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   
57.
58.
59.
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   
60.
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