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   515911篇
  免费   34092篇
  国内免费   619篇
耳鼻咽喉   6935篇
儿科学   16885篇
妇产科学   13553篇
基础医学   85373篇
口腔科学   14680篇
临床医学   44534篇
内科学   94210篇
皮肤病学   12251篇
神经病学   36355篇
特种医学   18506篇
外国民族医学   63篇
外科学   77278篇
综合类   8486篇
一般理论   120篇
预防医学   39317篇
眼科学   12169篇
药学   40712篇
中国医学   1022篇
肿瘤学   28173篇
  2018年   5041篇
  2015年   4594篇
  2014年   6186篇
  2013年   9691篇
  2012年   13109篇
  2011年   14533篇
  2010年   8421篇
  2009年   7862篇
  2008年   13834篇
  2007年   14875篇
  2006年   15063篇
  2005年   14477篇
  2004年   14119篇
  2003年   13448篇
  2002年   13327篇
  2001年   24110篇
  2000年   25108篇
  1999年   20590篇
  1998年   5440篇
  1997年   4711篇
  1996年   5048篇
  1995年   4629篇
  1994年   4324篇
  1993年   4141篇
  1992年   15744篇
  1991年   16323篇
  1990年   16431篇
  1989年   15808篇
  1988年   14584篇
  1987年   14424篇
  1986年   13601篇
  1985年   12984篇
  1984年   9630篇
  1983年   8253篇
  1982年   4560篇
  1981年   4230篇
  1979年   9424篇
  1978年   6863篇
  1977年   5776篇
  1976年   5604篇
  1975年   6399篇
  1974年   7639篇
  1973年   7134篇
  1972年   6961篇
  1971年   6687篇
  1970年   6177篇
  1969年   5897篇
  1968年   5559篇
  1967年   5020篇
  1966年   4455篇
排序方式: 共有10000条查询结果,搜索用时 1 毫秒
31.
32.
33.
34.
Thyroid diseases are common, and use of levothyroxine is increasing worldwide. We investigated the influence of gender, race and socioeconomic status on the diagnosis and treatment of thyroid disorders using data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of civil servants (35-74 years of age) from six Brazilian cities. Diagnosis of thyroid dysfunction was by thyrotropin (TSH), and free thyroxine (FT4) if TSH was altered, and the use of specific medications. Multivariate logistic regression models were constructed using overt hyperthyroidism/hypothyroidism and levothyroxine use as dependent variables and sociodemographic characteristics as independent variables. The frequencies of overt hyper- and hypothyroidism were 0.7 and 7.4%, respectively. Using whites as the reference ethnicity, brown, and black race were protective for overt hypothyroidism (OR=0.76, 95%CI=0.64-0.89, and OR=0.53, 95%CI=0.43-0.67, respectively, and black race was associated with overt hyperthyroidism (OR=1.82, 95%CI=1.06-3.11). Frequency of hypothyroidism treatment was higher in women, browns, highly educated participants and those with high net family incomes. After multivariate adjustment, levothyroxine use was associated with female gender (OR=6.06, 95%CI=3.19-11.49) and high net family income (OR=3.23, 95%CI=1.02-10.23). Frequency of hyperthyroidism treatment was higher in older than in younger individuals. Sociodemographic factors strongly influenced the diagnosis and treatment of thyroid disorders, including the use of levothyroxine.  相似文献   
35.
36.
37.
38.
39.
40.
At this study a multi-criteria model was developed to examine the available procedures, techniques and methods of handling infectious waste in the large healthcare unit of University Regional General Hospital of Patras, Western Greece. Particularly, this study examined the: a) current legislation and Directives issued for medical waste management at Greece and among the other EU-members, b) contribution of healthcare wastes (HCW) generation rate on social and economic parameters in selected European countries, c) available procedures, techniques, and methods upon the disposal of infectious wastes at the healthcare studied, and, d) propositions for integrated management of such hazardous wastes. Specifically, the Analytic Hierarchy Process (AHP) methodology was applied under pair wise comparison matrices in two stages: 1) the scale factors and the indicators, and 2) the criteria and their sub–criteria. The assessment of these pair wise matrices included the indicators and the sub–criteria. Subsequently, two pair wise comparison matrices, upon a) the “Fulfillment of environmental objectives” indicator and b) the “Energy consumption” sub criterion, were denoted. The AHP methodology yielded good results; however there is still space of improving the environmental performance. The normalized relative weights obtained for the criteria and sub criteria motivated specific actions that have to be handled. Particularly, the results indicated a very good value in environmental management criteria due the values obtained for the commitment towards the environmental policy standards and the waste management procedures. However, further improvements on staff awareness (such as development programs to enhance sensitivity) and more green purchasing suppliers, should be further addressed.  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