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   20796篇
  免费   1645篇
  国内免费   342篇
耳鼻咽喉   562篇
儿科学   4795篇
妇产科学   172篇
基础医学   1095篇
口腔科学   145篇
临床医学   2141篇
内科学   1387篇
皮肤病学   163篇
神经病学   3894篇
特种医学   500篇
外科学   1479篇
综合类   1792篇
预防医学   2968篇
眼科学   146篇
药学   1111篇
  6篇
中国医学   198篇
肿瘤学   229篇
  2024年   32篇
  2023年   373篇
  2022年   712篇
  2021年   961篇
  2020年   865篇
  2019年   804篇
  2018年   755篇
  2017年   857篇
  2016年   908篇
  2015年   859篇
  2014年   1416篇
  2013年   1670篇
  2012年   1291篇
  2011年   1452篇
  2010年   1113篇
  2009年   1155篇
  2008年   1183篇
  2007年   1088篇
  2006年   885篇
  2005年   747篇
  2004年   582篇
  2003年   454篇
  2002年   408篇
  2001年   359篇
  2000年   284篇
  1999年   209篇
  1998年   185篇
  1997年   120篇
  1996年   110篇
  1995年   118篇
  1994年   81篇
  1993年   89篇
  1992年   77篇
  1991年   58篇
  1990年   43篇
  1989年   56篇
  1988年   59篇
  1987年   45篇
  1986年   54篇
  1985年   46篇
  1984年   38篇
  1983年   18篇
  1982年   15篇
  1981年   22篇
  1980年   20篇
  1979年   25篇
  1978年   15篇
  1976年   16篇
  1975年   14篇
  1974年   15篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
《Vaccine》2020,38(42):6508-6516
BackgroundPneumococcal conjugate vaccine (PCV) effectiveness against radiographic pneumonia in South Asia is unknown. Bangladesh introduced PCV10 in 2015 using a three dose primary series (3 + 0). We sought to measure PCV10 effectiveness for two or more vaccine doses on radiographic pneumonia among vaccine-eligible children in rural Bangladesh.MethodsWe conducted a matched case-control study over two years from 2015 to 2017 using clinic and community controls in three subdistricts of Sylhet, Bangladesh. Cases were vaccine eligible 3–35 month olds at Upazila Health Complex outpatient clinics with World Health Organization-defined radiographic primary endpoint pneumonia (radiographic pneumonia). Clinic controls were matched to cases within a one week time window by age, sex, and clinic and had an illness unlikely to be Streptococcus pneumoniae; community controls were healthy and similarly matched within a one week time window by age and sex, and distance from the clinic. We estimated adjusted vaccine effectiveness (aVE) using conditional logistic regression.ResultsWe matched 1262 cases with 2707 clinic and 2461 community controls. Overall, aVE using clinic controls was 21.4% (95% confidence interval, −0.2%, 38.4%) for ≥2 PCV10 doses and among 3–11 month olds was 47.3% (10.5%, 69.0%) for three doses. aVE increased with higher numbers of doses in clinic control sets (p = 0.007). In contrast, aVE using community controls was 7.6% (95% confidence interval, −22.2%, 30.0%) for ≥2 doses. We found vaccine introduction in the study area faster and less variable than expected with 75% coverage on average, which reduced power. Information bias may also have affected community controls.ConclusionsClinic control analyses show PCV10 prevented radiographic pneumonia in Bangladesh, especially among younger children receiving three doses. While both analyses were underpowered, community control enrollment – compared to clinic controls – was more difficult in a complex, pluralistic healthcare system. Future studies in comparable settings may consider alternative study designs.  相似文献   
13.
14.
15.
16.
Between the 1930s and 1960s Puerto Rico was transformed from a marginal United States territory into an industrialised ‘showcase of development’. This article investigates the organisation of milk station programmes on the island during this crucial period and how these reflected the circulation of child welfare knowledge, nutrition expertise and public health practices. During the Depression, these perspectives fostered a recast of the eugenic regeneration ideologies motivating medical assessments of and sanitary interventions with Puerto Rico’s rural poor since the nineteenth century. Innovations in nutrition knowledge and an emerging rural hygiene movement highlighted the negative health effects of the island’s monocrops economy. In this context, the nourishment of children’s bodies assumed symbolic and instrumental significance for the reconfiguration of colonial and developmental models promoted by the new Popular Democratic Party (PPD). The experience of public health professionals in relief work during the 1930s contributed to the articulation of food and nutrition as key elements of this party’s populist discourse. Programmes like milk stations became part of strategies to rear and manage the labour force needed in the industrial development model promoted by the PPD. From the perspective of poor Puerto Ricans, however, they were part of the materialisation of its promise of social justice for the poorer classes.  相似文献   
17.
ObjectiveTo present, the process of development and evaluation of an educational software on the Child Health Handbook proposed for the continuing education of primary care nurses and physicians.MethodsQuantitative study of methodological development. For software development, the following steps were followed: definition of objectives; determination of the target audience; choice of pedagogical and theoretical reference for content; content selection and structuring; software development and evaluation by experts (five nurses and four physicians). All responded to an instrument that included four domains: pedagogical; content; functionality; system presentation and usability. The evaluation criteria were arranged on a Likert-type scale. The percentage of agreement and Content Validity Index were used for the quantitative analysis of the degree of agreement, considering a Content Validity Index cutoff point equal to 0.80.ResultsThe overall agreement index, calculated by the arithmetic mean of the Contents Validity Index of the evaluated domains, was 0.96, with scores ranging from 0.90 to 1.00. The average percentage of agreement of the experts per domain was 92.86%, with lower agreement in the content (80.95%), presentation, and usability (90.48%) domains. 100% of percentage of agreement was observed in the pedagogical and functionality domains among the evaluated specialists.ConclusionThe percentage of agreement, Content Validity Index and overall agreement index of the Child Health Handbook educational software in the context of primary care disclosed the software adequacy as an educational resource for continuing education of primary care nurses and physicians. Considering the assessed dimensions, it can also be used by other health professionals and undergraduate students.  相似文献   
18.
19.
ObjectivesGrowing evidence of the importance of motor competence for developing a healthy lifestyle has been established in the last decade. Nonetheless, no single instrument or observation tool have been able to fully measure this construct, particularly because most were built for the diagnosis of children in risk for motor impairment; are limited to a few years of the developmental span; lack objectivity in the assessment protocols; or do not include the locomotor, stability, and manipulative components. This led to the difficulty of comparing researches, and longitudinally follow children into adulthood. Recently, a novel proposal to assess motor competence was presented - the Motor Competence Assessment (MCA) - and this study aims to present the MCA normative data from 3-to-23 years.Design and methodsTwo thousand and eighty-seven participants (1102 boys) between 3 and 23 years of age were evaluated in the MCA (standing long jump, 10 m shuttle run, throwing velocity, kicking velocity, lateral jumps, shifting platforms). Results for each test were introduced in the LMS Chartmaker 2.3. The best model for test and sex was used, resulting in normative curves and percentile values.ResultsFinal norms showed a good fit to the instrument developmental expectations, allowing to differentiate and classify performances along the age interval.ConclusionsThe MCA age- and sex- normative values allow to assess motor competence from childhood to early adulthood. Future directions will include obtaining a total MCA score and the normative scores for the MCA components (stability, locomotion, object control), and to expand the norms to adulthood and old age.  相似文献   
20.
我国小儿骨科源起于20世纪50年代,中华人民共和国成立后,曾经在欧美国家接受过现代骨科学教育的中国骨科奠基人孟继懋、叶衍庆、方先之等学者们先后在北京、上海、天津等大城市组建了骨科为主的医院或研究所:北京积水潭医院、上海瑞金医院伤骨科研究所、天津骨科医院等,专门诊治骨科患者并进行教学和科研培训,早期主要治疗骨髓炎、骨结核、骨折等疾病[1]。1954 年天津骨科医院成立了专门的小儿骨科,是国内最早成立的独立建制的科室。  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