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   1417715篇
  免费   100108篇
  国内免费   2340篇
耳鼻咽喉   19980篇
儿科学   46285篇
妇产科学   41209篇
基础医学   207692篇
口腔科学   40355篇
临床医学   116637篇
内科学   282973篇
皮肤病学   30565篇
神经病学   111060篇
特种医学   53546篇
外国民族医学   367篇
外科学   213393篇
综合类   27190篇
现状与发展   1篇
一般理论   326篇
预防医学   108977篇
眼科学   32947篇
药学   108885篇
  1篇
中国医学   3025篇
肿瘤学   74749篇
  2018年   16323篇
  2017年   11785篇
  2016年   12910篇
  2015年   14737篇
  2014年   19532篇
  2013年   29715篇
  2012年   42700篇
  2011年   45540篇
  2010年   25973篇
  2009年   23573篇
  2008年   42810篇
  2007年   46280篇
  2006年   46566篇
  2005年   45437篇
  2004年   43426篇
  2003年   41909篇
  2002年   41127篇
  2001年   61770篇
  2000年   63652篇
  1999年   53817篇
  1998年   14841篇
  1997年   13219篇
  1996年   13443篇
  1995年   12685篇
  1994年   12034篇
  1992年   42717篇
  1991年   41865篇
  1990年   41411篇
  1989年   39999篇
  1988年   37362篇
  1987年   36488篇
  1986年   34897篇
  1985年   33227篇
  1984年   24713篇
  1983年   21480篇
  1982年   12739篇
  1981年   11249篇
  1979年   23600篇
  1978年   16530篇
  1977年   14366篇
  1976年   13579篇
  1975年   14932篇
  1974年   17562篇
  1973年   17015篇
  1972年   16205篇
  1971年   15117篇
  1970年   14031篇
  1969年   13624篇
  1968年   12885篇
  1967年   11278篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
2.
3.
4.
5.
6.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
7.
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children.  相似文献   
8.
9.
This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.

The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same.  相似文献   

10.
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