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   467068篇
  免费   32205篇
  国内免费   4168篇
耳鼻咽喉   6399篇
儿科学   10510篇
妇产科学   11547篇
基础医学   62639篇
口腔科学   13590篇
临床医学   39526篇
内科学   94775篇
皮肤病学   9979篇
神经病学   34823篇
特种医学   16812篇
外国民族医学   90篇
外科学   74207篇
综合类   15008篇
现状与发展   10篇
一般理论   162篇
预防医学   25083篇
眼科学   11363篇
药学   38065篇
  29篇
中国医学   4198篇
肿瘤学   34626篇
  2022年   2773篇
  2021年   5871篇
  2020年   3825篇
  2019年   5186篇
  2018年   7210篇
  2017年   5713篇
  2016年   5615篇
  2015年   6615篇
  2014年   9170篇
  2013年   11870篇
  2012年   16464篇
  2011年   16797篇
  2010年   10223篇
  2009年   9272篇
  2008年   14895篇
  2007年   15757篇
  2006年   15414篇
  2005年   14316篇
  2004年   13351篇
  2003年   12734篇
  2002年   12105篇
  2001年   29083篇
  2000年   29444篇
  1999年   24402篇
  1998年   5928篇
  1997年   4937篇
  1996年   4441篇
  1995年   4020篇
  1994年   3622篇
  1993年   3279篇
  1992年   16467篇
  1991年   15207篇
  1990年   14481篇
  1989年   14271篇
  1988年   12879篇
  1987年   12338篇
  1986年   11396篇
  1985年   10701篇
  1984年   7371篇
  1983年   5980篇
  1982年   3258篇
  1981年   2723篇
  1979年   5696篇
  1978年   3633篇
  1977年   3247篇
  1975年   2871篇
  1974年   3256篇
  1973年   3058篇
  1972年   2984篇
  1971年   2893篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
BACKGROUNDNasolacrimal duct obstruction leading to epiphora is a common ophthalmologic complaint, and it may derive from amyloidosis in rare cases. There are a few reports about localized amyloidosis, and amyloidosis with involvement and obstruction of the nasolacrimal duct is exceedingly rare. CASE SUMMARYA 54-year-old male presented with a 2-year history of a lump overlying the left lacrimal sac that had grown rapidly for nearly half a year. Physical examination touched a firm lump in the left lacrimal sac. Nasal endoscopy discovered lesions in appearance of sediments with easy bleeding at the entry of the nasolacrimal duct of the left inferior nasal meatus. Computerized tomography scan revealed speckle high density in the left lacrimal sac and the dilated nasolacrimal duct. During an endoscopic exploration and excision, a large number of dacryoliths were exposed. Pathology indicated amorphous pink material and multinucleated giant cell reaction in the fibrous tissue.CONCLUSIONThis case showed amyloidosis in localized form mimicking dacryolith with nasolacrimal duct obstruction. In clinical practice, we should be aware of the possibility of localized amyloidosis in the nasolacrimal excretory system.  相似文献   
73.
74.
75.
76.
随着对肿瘤热疗和肿瘤免疫微环境(TIME)的深入研究,近年来热疗对TIME的作用越来越受到学者们的重视。本文就目前国内外研究进展,对热疗与TIME中几类主要免疫细胞和免疫相关细胞因子的影响及作用机制作一综述。全面而透彻的了解热疗对TIME的调控作用,有助于为肿瘤治疗提供新的思路和方法。  相似文献   
77.
Neuroimaging studies using the social-exclusion paradigm Cyberball indicate increased dorsal anterior cingulate cortex (dACC) and right insula activity as a function of exclusion. However, comparatively less work has been done on how social status factors may moderate this finding. This study used the Cyberball paradigm with 85 (45 females) socio-economically diverse participants from a larger longitudinal sample. We tested whether neighborhood quality during adolescence would predict subsequent neural responding to social exclusion in young adulthood. Given previous behavioral studies indicating greater social vigilance and negative evaluation as a function of lower status, we expected that lower adolescent neighborhood quality would predict greater dACC activity during exclusion at young adulthood. Our findings indicate that young adults who lived in low-quality neighborhoods in adolescence showed greater dACC activity to social exclusion than those who lived in higher quality neighborhoods. Lower neighborhood quality also predicted greater prefrontal activation in the superior frontal gyrus, dorsal medial prefrontal cortex and the middle frontal gyrus, possibly indicating greater regulatory effort. Finally, this effect was not driven by subsequent ratings of distress during exclusion. In sum, adolescent neighborhood quality appears to potentiate neural responses to social exclusion in young adulthood, effects that are independent of felt distress.  相似文献   
78.
HIV risk in vulnerable groups such as itinerant male street labourers is often examined via a focus on individual determinants. This study provides a test of a modified Information-Motivation-Behavioral Skills (IMB) model to predict condom use behaviour among male street workers in urban Vietnam. In a cross-sectional survey using a social mapping technique, 450 male street labourers from 13 districts of Hanoi, Vietnam were recruited and interviewed. Collected data were first examined for completeness; structural equation modelling was then employed to test the model fit. Condoms were used inconsistently by many of these men, and usage varied in relation to a number of factors. A modified IMB model had a better fit than the original IMB model in predicting condom use behaviour. This modified model accounted for 49% of the variance, versus 10% by the original version. In the modified model, the influence of psychosocial factors was moderately high, whilst the influence of HIV prevention information, motivation and perceived behavioural skills was moderately low, explaining in part the limited level of condom use behaviour. This study provides insights into social factors that should be taken into account in public health planning to promote safer sexual behaviour among Asian male street labourers.  相似文献   
79.
80.
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