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   1332499篇
  免费   102036篇
  国内免费   4241篇
耳鼻咽喉   16790篇
儿科学   43572篇
妇产科学   36354篇
基础医学   197784篇
口腔科学   35905篇
临床医学   129445篇
内科学   257788篇
皮肤病学   26370篇
神经病学   111834篇
特种医学   48169篇
外国民族医学   366篇
外科学   183984篇
综合类   28764篇
现状与发展   1篇
一般理论   460篇
预防医学   114155篇
眼科学   28964篇
药学   98793篇
  6篇
中国医学   3165篇
肿瘤学   76107篇
  2021年   10884篇
  2019年   11627篇
  2018年   16302篇
  2017年   12285篇
  2016年   13249篇
  2015年   15196篇
  2014年   20800篇
  2013年   32054篇
  2012年   44238篇
  2011年   46892篇
  2010年   27074篇
  2009年   24919篇
  2008年   42715篇
  2007年   45051篇
  2006年   45164篇
  2005年   43591篇
  2004年   41559篇
  2003年   39495篇
  2002年   38305篇
  2001年   60846篇
  2000年   62515篇
  1999年   52278篇
  1998年   14581篇
  1997年   13275篇
  1996年   13115篇
  1995年   12459篇
  1994年   11627篇
  1993年   10922篇
  1992年   41571篇
  1991年   40765篇
  1990年   39445篇
  1989年   37343篇
  1988年   34581篇
  1987年   33694篇
  1986年   32151篇
  1985年   30638篇
  1984年   23036篇
  1983年   19589篇
  1982年   11752篇
  1979年   20804篇
  1978年   14814篇
  1977年   12064篇
  1976年   11876篇
  1975年   12110篇
  1974年   14800篇
  1973年   14472篇
  1972年   13356篇
  1971年   12419篇
  1970年   11485篇
  1969年   10410篇
排序方式: 共有10000条查询结果,搜索用时 835 毫秒
941.
942.
The study of the cognitive abilities of hearing-impaired children is important for both practical (e.g. to determine appropriate teaching strategies) and theoretical reasons (e.g. to examine the role of language in thought processes). The aim of this paper is to examine the cognitive function of hearing-impaired children from a review of the literature. If most studies show that deaf children are similar to normal children in virtually all aspects of cognitive function, many studies also emphasize pronounced differences in their academic achievement. Besides the degree of hearing loss and the age at onset of deafness, environmental factors (such as parental support and educational methods) seem to play an important role in the cognitive development and academic success of these children. This underlines the importance of the measures adopted for the deaf children as they may have a positive or negative impact on their development.  相似文献   
943.
Wodtke  J.  Kl&#;ber  D.  Frommelt  L.  L&#;hr  J. F. 《Trauma und Berufskrankheit》2005,7(1):S134-S138
Trauma und Berufskrankheit - Als schwerste Komplikation der Gelenkendoprothetik bleibt die periprothetische Infektion eine Herausforderung—heutzutage nicht nur für den Chirurgen, sondern...  相似文献   
944.
Occupational diseases Nos. 2108 and 2110 correspond to intervertebral disc-related diseases of the lumbar spine from many years of carrying or lifting heavy loads, occupations in extreme postures of full flexion or oscillation of the whole body when seated, and which compel the cessation of all activities which are or could be the cause for the origin, exacerbation or recurrence of the disease. These occupational diseases came into force at the start of 1993, but there have been considerable problems in their implementation. The present Part I of the contribution is the result of the work of an interdisciplinary study group and contains medical criteria for the assessment of possibly strain-related clinical characteristics and the evaluation of other possible causes. Part II is to be published in Volume 4/2005 and will deal with questions related to forced cessation and to the assessment of the loss of earning ability. Agreement was reached in many areas related to the assessment of occupational claims. This should allow for evidence-based decision making in the future for the occupational diseases Nos. 2108 and 2110.  相似文献   
945.
Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD.  相似文献   
946.
947.
948.
949.
Folate receptor alpha (FRalpha) expression in epithelial ovarian cancer may be related to folate intake. We examined this association using multivitamin intake, a proxy for folic acid, and assessed whether the relation was modified by alcohol intake, a folate agonist. Cases (n = 148) with suspected epithelial ovarian cancer, of ages > or = 20 years, were seen at Mayo Clinic, Minnesota, between 2000 and 2004; those with tumor specimens (n = 108) were included in analyses. Outpatient controls (n = 148) without cancer and with at least one ovary intact were matched to cases by age (within 5 years) and state of residence. Multivitamin (> or = 4 pills/wk) and weekly alcohol (> or = 5 drinks) intakes were assessed. Tumor specimens were analyzed immunohistochemically for FRalpha. Multivariable rate ratios (RR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression. In case-control analysis, the RRs of multivitamin intake with absent/weak/moderate and strong-expressing FRalpha tumors were 0.30 (95% CI, 0.12-0.70) and 0.47 (95% CI, 0.24-0.91), respectively. For alcohol, the associations were 0.84 (95% CI, 0.24-2.86) and 1.65 (95% CI, 0.69-3.93), respectively. In case-case analysis, the RR associated with developing strong-expressing versus other FRalpha tumors was 3.13 (95% CI, 1.14-8.65) for multivitamins and 1.58 (95% CI, 0.45-5.60) for alcohol. The data did not support evidence for an interaction between multivitamin and alcohol intake with risk of developing a strong-expressing FRalpha tumor. The association of multivitamin intake with ovarian cancer may depend on FRalpha expression level.  相似文献   
950.
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