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   1758235篇
  免费   131792篇
  国内免费   7718篇
耳鼻咽喉   22926篇
儿科学   56645篇
妇产科学   47857篇
基础医学   249465篇
口腔科学   49698篇
临床医学   159087篇
内科学   343669篇
皮肤病学   39405篇
神经病学   135670篇
特种医学   66185篇
外国民族医学   294篇
外科学   263425篇
综合类   46791篇
现状与发展   23篇
一般理论   533篇
预防医学   128631篇
眼科学   42108篇
药学   131278篇
  69篇
中国医学   7458篇
肿瘤学   106528篇
  2021年   15874篇
  2019年   15719篇
  2018年   22396篇
  2017年   17268篇
  2016年   18656篇
  2015年   21746篇
  2014年   29811篇
  2013年   41182篇
  2012年   57556篇
  2011年   60909篇
  2010年   36044篇
  2009年   32986篇
  2008年   54956篇
  2007年   58539篇
  2006年   59051篇
  2005年   56255篇
  2004年   53556篇
  2003年   50934篇
  2002年   48697篇
  2001年   93135篇
  2000年   95065篇
  1999年   78417篇
  1998年   20665篇
  1997年   18120篇
  1996年   18052篇
  1995年   17346篇
  1994年   15792篇
  1993年   14391篇
  1992年   57738篇
  1991年   55574篇
  1990年   53257篇
  1989年   50965篇
  1988年   46366篇
  1987年   45123篇
  1986年   42413篇
  1985年   40138篇
  1984年   29465篇
  1983年   24998篇
  1982年   13954篇
  1979年   25619篇
  1978年   17626篇
  1977年   14946篇
  1976年   13899篇
  1975年   14609篇
  1974年   17679篇
  1973年   16975篇
  1972年   15701篇
  1971年   14477篇
  1970年   13449篇
  1969年   12534篇
排序方式: 共有10000条查询结果,搜索用时 531 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.
综述了脑血管介入术穿刺点压迫方法(包括人工压迫、弹力带加压、压迫器加压、血管闭合装置压迫、止血敷料压迫、气囊加压6种)、止血压力以及压迫时间,提出由于穿刺点和压迫方法的不同,其压迫时间、减压时间和压力大小等需要进一步探讨,为脑血管介入术后患者穿刺点的临床护理提供参考。  相似文献   
3.
Die Anaesthesiologie - Auch wenn für Anästhesiologen über Jahrzehnte die Prophylaxe und Therapie postoperativer Schmerzen im Rahmen des postoperativen Patientenkomforts an vorderster...  相似文献   
4.
5.
6.
7.
8.
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.  相似文献   
9.
Noninvasive imaging of cardiac fibrosis is important for early diagnosis and intervention in chronic heart diseases. Here, we investigated whether noninvasive, contrast agent-free MRI T2-mapping can quantify myocardial fibrosis in preclinical models of aging and pressure overload. Myocardial fibrosis and remodeling were analyzed in two animal models: (i) aging (15-month-old male CF-1 mice vs. young 6- to 8-week-old mice), and (ii) pressure overload (PO; by transverse aortic constriction in 4- to 5-month-old male C57BL/6 mice vs. sham-operated for 14 days). In vivo T2-mapping was performed by acquiring data during the isovolumic and early diastolic phases, with a modified respiratory and ECG-triggered multiecho TurboRARE sequence on a 7-T MRI. Cine MRI provided cardiac morphology and function. A quantitative segmentation method was developed to analyze the in vivo T2-maps of hearts at midventricle, apex, and basal regions. The cardiac fibrosis area was analyzed ex vivo by picro sirius red (PSR) staining. Both aged and pressure-overloaded hearts developed significant myocardial contractile dysfunction, cardiac hypertrophy, and interstitial fibrosis. The aged mice had two phenotypes, fibrotic and mild-fibrotic. Notably, the aged fibrotic subgroup and the PO mice showed a marked decrease in T2 relaxation times (25.3 ± 0.6 in aged vs. 29.9 ± 0.7 ms in young mice, p = 0.002; and 24.3 ± 1.7 in PO vs. 28.7 ± 0.7 ms in shams, p = 0.05). However, no significant difference in T2 was detected between the aged mild-fibrotic subgroup and the young mice. Accordingly, an inverse correlation between myocardial fibrosis percentage (FP) and T2 relaxation time was derived (R2 = 0.98): T2 (ms) = 30.45 – 1.05 × FP. Thus, these results demonstrate a statistical agreement between T2-map–quantified fibrosis and PSR staining in two different clinically relevant animal models. In conclusion, T2-mapping MRI is a promising noninvasive contrast agent-free quantitative technique to characterize myocardial fibrosis.  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