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   1696181篇
  免费   123856篇
  国内免费   3781篇
耳鼻咽喉   21758篇
儿科学   55652篇
妇产科学   46165篇
基础医学   241351篇
口腔科学   48763篇
临床医学   151420篇
内科学   333732篇
皮肤病学   38663篇
神经病学   131199篇
特种医学   63940篇
外国民族医学   242篇
外科学   257284篇
综合类   38967篇
现状与发展   4篇
一般理论   532篇
预防医学   124376篇
眼科学   40229篇
药学   123722篇
  7篇
中国医学   4484篇
肿瘤学   101328篇
  2021年   12799篇
  2019年   13534篇
  2018年   19965篇
  2017年   15226篇
  2016年   16627篇
  2015年   18969篇
  2014年   26226篇
  2013年   37968篇
  2012年   52755篇
  2011年   55456篇
  2010年   32800篇
  2009年   30713篇
  2008年   51570篇
  2007年   54872篇
  2006年   55337篇
  2005年   52598篇
  2004年   50801篇
  2003年   48203篇
  2002年   46427篇
  2001年   91825篇
  2000年   93645篇
  1999年   76993篇
  1998年   19728篇
  1997年   17275篇
  1996年   17405篇
  1995年   16753篇
  1994年   15295篇
  1993年   14073篇
  1992年   57393篇
  1991年   55285篇
  1990年   52989篇
  1989年   50762篇
  1988年   46139篇
  1987年   44947篇
  1986年   42238篇
  1985年   40000篇
  1984年   29360篇
  1983年   24922篇
  1982年   13905篇
  1979年   25544篇
  1978年   17584篇
  1977年   14915篇
  1976年   13879篇
  1975年   14567篇
  1974年   17639篇
  1973年   16950篇
  1972年   15681篇
  1971年   14461篇
  1970年   13433篇
  1969年   12526篇
排序方式: 共有10000条查询结果,搜索用时 96 毫秒
111.
112.
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   
113.
114.
115.
Facial reanimation after acoustic neuroma excision is currently accomplished using a variety of surgical techniques. A multi-institutional survey of patient perceptions of facial reanimation success was accomplished by mailing a questionnaire to 809 randomly selected members of the Acoustic Neuroma Association. Four hundred sixty patients who underwent 296 reanimation procedures responded. Facial to hypoglossal nerve anastomosis, tarsorrhaphy, and upper eyelid implants were most frequently performed. The patient's estimations of initial deficit, spontaneous recovery, and overall satisfaction with the reanimation procedures are discussed.  相似文献   
116.
38 cases of acute multilocular osteomyelitis out of a total of 165 osteomyelitis patients were treated between 1974 and 1986 at the Department of Paediatric Surgery and Paediatric Diseases at the University of Mainz. Osteomyelitis in infants was separated from juvenile osteomyelitis because of the different problems inherent to this disease depending upon the age; likewise, multilocular remote involvement was separated from regional multiple involvement. It was found that distant involvement is of special importance in infancy. 6 of the 8 cases in this group presented with symmetrical involvement. This interesting phenomenon is described in this article for the first time in acute multilocular osteomyelitis; so far, it was known to occur only in chronic recurrent multifocal osteomyelitis (CRMO). The infants in this group were predominantly newborn who were particularly severely handicapped by predisposing factors such as necessary intensive-care measures or surgical interventions. Our findings showed that in this age group most of the problems occurred, namely: 3 deaths and 2 healing defects in 8 children. For this reason it is imperative to effect particularly close monitoring of multilocular acute osteomyelitis in infancy. This must be considered as a paediatric and paediatric-surgical emergency requiring not only accurate diagnostic measures but also early internistic and surgical treatment to improve the prognosis of this specific disease pattern.  相似文献   
117.
The Authors examine the correlation between hypertensive disorders of pregnancy and fetal growth. The results of a study of 342 pregnancies, confirm a significant correlation between hypertension and fetal growth retardation. These findings, so evident in moderate and severe hypertension, have also been confirmed in cases of mild hypertension. The medical treatment also in the pregnancies with mild hypertension, and a larger utilisation of operative deliveries, determined a decrease in perinatal mortality and morbidity.  相似文献   
118.
The decoction of Sclerocarya birroea Hochst. shows hypoglycaemic effects, an increase in plasma IRI in normal rats and an incremented oral-glucose tolerance. The decoction is also active against diet-induced hypercholesterolaemia.  相似文献   
119.
120.
Eight-eight female weanling Sprague-Dawley rats were fed diets containing either 650 or 150 mg magnesium/kg diet and 7.0 or 3.5 mg pyridoxine-HCl/kg diet, in a 2 x 2 factorial arrangement, during growth, gestation, and lactation. The objective of the study was to determine whether concurrent dietary deficiencies of magnesium and pyridoxine were synergistic, additive, or antagonistic with regards to effects on reproductive performance, growth, and development of offspring, and tissue content of magnesium and calcium. Body weight of dams and pups was not different between groups until day 9 of lactation, at which point those animals in either low magnesium group weighed less than the other. Litter size and birth weight were not different. Development, as measured by timing of unfolding of the external ear, opening of both eyes, and clinical emergence of incisors, was delayed in pups from litters in the low magnesium groups. A synergistic effect on delay of onset of ear unfolding by deficiency of both magnesium and pyridoxine was observed. Calcium content of heart and kidney from dams was increased in the low magnesium groups. Renal calcium was not further increased by the level of pyridoxine deficiency in this study. The calcium to magnesium ratio in heart from pups was higher in those from litters in the low magnesium and pyridoxine group than in the others. Results indicate that simultaneous deficiencies of magnesium and pyridoxine may impair function synergistically. Because these two nutrients are often reported to be presented in inadequate amounts in diets of women in their reproductive years, the potential exists for impaired reproductive success.  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