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   750篇
  免费   46篇
  国内免费   2篇
耳鼻咽喉   6篇
儿科学   21篇
妇产科学   15篇
基础医学   72篇
口腔科学   48篇
临床医学   71篇
内科学   134篇
皮肤病学   19篇
神经病学   67篇
特种医学   14篇
外国民族医学   1篇
外科学   70篇
综合类   4篇
一般理论   2篇
预防医学   66篇
眼科学   2篇
药学   147篇
中国医学   4篇
肿瘤学   35篇
  2024年   4篇
  2023年   12篇
  2022年   20篇
  2021年   30篇
  2020年   19篇
  2019年   24篇
  2018年   26篇
  2017年   22篇
  2016年   14篇
  2015年   17篇
  2014年   20篇
  2013年   40篇
  2012年   50篇
  2011年   42篇
  2010年   29篇
  2009年   27篇
  2008年   36篇
  2007年   41篇
  2006年   33篇
  2005年   42篇
  2004年   31篇
  2003年   42篇
  2002年   35篇
  2001年   34篇
  2000年   25篇
  1999年   22篇
  1998年   6篇
  1997年   3篇
  1996年   4篇
  1995年   2篇
  1994年   2篇
  1993年   3篇
  1992年   7篇
  1991年   5篇
  1989年   2篇
  1987年   3篇
  1986年   5篇
  1984年   2篇
  1982年   2篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1972年   1篇
  1970年   1篇
  1946年   1篇
  1938年   1篇
  1935年   1篇
  1932年   1篇
  1927年   1篇
  1924年   1篇
排序方式: 共有798条查询结果,搜索用时 15 毫秒
101.
102.
103.
The on-going search for a biologically acceptable restorative material has brought a confusing variety of composites on the dental market. In the present study, commercially available composites are categorized as a function of their mean particle size, filler distribution, filler content, Young's modulus, surface roughness, compressive strength, surface hardness, and filler morphology. Out of this information, it can be concluded that the materials of choice for restoring posterior cavities at present are the Ultrafine Compact-Filled Composites because their intrinsic surface roughness, Young's modulus and, indirectly, their filler content, compressive strength, and surface hardness are comparable to the same properties of enamel and dentin. The Ultrafine Midway-Filled Composites seem to be very satisfactory materials for anterior use.  相似文献   
104.

Background  

Biological control methods are once again being given much research focus for malaria vector control. This is largely due to the emerging threat of strong resistance to pesticides. Larvivorous fish have been used for over 100 years in mosquito control and many species have proved effective. In the western Kenyan highlands the larvivorous fish Oreochromis niloticus L. (Perciformes: Cichlidae) (formerly Tilapia nilotica) is commonly farmed and eaten but has not been previously tested in the field for malaria mosquito control.  相似文献   
105.
106.
107.
108.
109.
A bstract — Cost-benefit and cost-effectiveness analyses were carried out to obtain an indication of the economic viability of the prolonged fluoride application (PFA) method. Using three year results from a clinical trial of the technique, the cost-benefit ratio was calculated as 1:2.1 and the cost-effectiveness as $3.49 per surface saved in three years. For purposes of general comparison the same analyses were made for an alternative measure, the placement of pit and fissure sealants. Using data from a two-year sealant trial, the cost-benefit ratio was found to be 1:0.77 and the cost-effectiveness $18.49 per surface saved in two years. The findings indicated that the PFA method can be regarded as an economically viable procedure.  相似文献   
110.
Competitive inhibition of binding between radioiodine-labelled encephalitogenic basic protein from human myelin (125I-HEProt) and normal human alpha-2 macroglobulin and between 125I-HEProt and rabbit antiHEProt serum was used to study concentrated cerebrospinal fluid (CSF) under “blind” control for cross-reactivity with HEProt. Samples of CSF from patients meeting the standard criteria for definite MS and possible MS, and from patients with optic neuritis and “other” diagnoses were studied. CSF from patients in all four groups was shown to have an inhibitor cross-reactive with HEProt when studied by the 125I-HEProt/alpha-2 macroglobulin test, but the amount was significantly greater in the definite MS group than in the “other” group. Results of the two tests on CSF from MS patients correlated, suggesting that the tests were identifying the same inhibitor. It was concluded that CSF contains an inhibitor similar to HEProt and that the amount present in CSF could be a useful diagnostic marker of MS.  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