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   4310990篇
  免费   363605篇
  国内免费   17287篇
耳鼻咽喉   59290篇
儿科学   138906篇
妇产科学   115205篇
基础医学   660922篇
口腔科学   118913篇
临床医学   408894篇
内科学   778044篇
皮肤病学   107531篇
神经病学   366809篇
特种医学   166694篇
外国民族医学   816篇
外科学   647693篇
综合类   127666篇
现状与发展   59篇
一般理论   2588篇
预防医学   369348篇
眼科学   100375篇
药学   298245篇
  24篇
中国医学   12472篇
肿瘤学   211388篇
  2021年   57124篇
  2020年   37851篇
  2019年   59554篇
  2018年   77312篇
  2017年   59933篇
  2016年   66009篇
  2015年   79103篇
  2014年   114515篇
  2013年   180606篇
  2012年   125821篇
  2011年   131007篇
  2010年   128883篇
  2009年   131225篇
  2008年   115988篇
  2007年   122397篇
  2006年   131502篇
  2005年   125813篇
  2004年   125838篇
  2003年   115467篇
  2002年   104373篇
  2001年   155555篇
  2000年   150754篇
  1999年   139368篇
  1998年   72082篇
  1997年   68281篇
  1996年   66033篇
  1995年   61410篇
  1994年   55270篇
  1993年   51329篇
  1992年   100381篇
  1991年   96145篇
  1990年   91914篇
  1989年   88978篇
  1988年   82396篇
  1987年   80466篇
  1986年   76169篇
  1985年   74793篇
  1984年   63671篇
  1983年   56857篇
  1982年   47134篇
  1981年   43889篇
  1980年   41186篇
  1979年   54494篇
  1978年   44755篇
  1977年   39557篇
  1976年   37019篇
  1975年   36009篇
  1974年   39610篇
  1973年   38429篇
  1972年   35850篇
排序方式: 共有10000条查询结果,搜索用时 121 毫秒
981.
982.
ObjectiveClinical specialty societies recommend long-acting reversible contraceptives (LARCs) as first-line contraception for adolescent women. We evaluated whether a combined educational and process improvement intervention enhanced LARC placement in primary care within an integrated health care system.MethodsThe intervention included journal clubs, live continuing education, point-of-care guidelines, and new patient materials. We conducted a retrospective cohort study across 3 time periods: baseline (January 2013?September 2015), early implementation (October 2015–March 2016), and full implementation (April 2016–June 2017). The primary outcome was the proportion of LARCs placed by primary care clinicians among women aged 13 to 18 years compared with gynecology clinicians.ResultsKaiser Foundation Health Plan of Colorado cared for approximately 20,000 women aged 13 to 18 years in each calendar quarter between 2013 and 2017. Overall, LARC placement increased from 7.0 per 1000 members per quarter at baseline to 13.0 per 1000 during the full intervention. Primary care clinicians placed 6.2% of all LARCs in 2013, increasing to 32.1% by 2017 (P < .001), including 45.5% of contraceptive implants. Clinicians who attended educational sessions were more likely to adopt LARCs than those who did not (17.9% vs 6.4% respectively, P = .009). Neither overall LARC placement rates (relative risk, 1.9; 95% confidence interval, 0.7?5.6) nor contraceptive implant rates (relative risk, 3.0; 95% confidence interval, 0.9?9.8) increased significantly in clinicians who attended educational activities.ConclusionsThis multimodal intervention was associated with increased LARC placement for adolescent women in primary care. The combination of education and process improvement is a promising strategy to promote clinician behavior change.  相似文献   
983.
984.
985.
986.
李焱  翟凤霞 《陕西中医》2020,(5):660-662
妊娠期间,咳嗽不已,称"妊娠咳嗽",亦称"子嗽",孕妇咳嗽日久未见好转,咳嗽胸痛甚则咳而呕吐,或咳嗽剧烈或久咳不愈,可损伤胎气,导致堕胎、小产。笔者运用六经辨证治疗外感型中表寒里热证子嗽,认为此类患者病在太阳阳明,属于寒热错杂之表寒里热,采用《伤寒论》中方证麻杏甘石汤合止嗽散,使热从外泄,宣发卫气,散寒不助热、解表不伤正,故辨证论治取得了显著的疗效。同时子嗽治疗还需注意健脾固肾安胎,应将顾护胎元贯穿治疗妊娠咳嗽的始终。  相似文献   
987.
988.
989.
Understanding the contribution of endothelial cells to the progenitor pools of adult tissues has the potential to inform therapies for human disease.To address whether endothelial cells transdifferentiate into non-vascular cell types,we performed cell lineage tracing analysis using transgenic mice engineered to express a fluorescent marker following activation by tamoxifen in vascular endothelial cadherin promoter-expressing cells(VEcad-CreERT2;B6 Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze).Activation of target-cell labeling following 1.5 months of ad libitum feeding with tamoxifen-laden chow in 4–5 month-old mice resulted in the tracing of central nervous system and peripheral cells that include:cerebellar granule neurons,ependymal cells,skeletal myocytes,pancreatic beta cells,pancreatic acinar cells,tubular cells in the renal cortex,duodenal crypt cells,ileal crypt cells,and hair follicle stem cells.As Nestin expression has been reported in a subset of endothelial cells,Nes-CreERT2 mice were also utilized in these conditions.The tracing of cells in adult Nes-CreERT2 mice revealed the labeling of canonical progeny cell types such as hippocampal and olfactory granule neurons as well as ependymal cells.Interestingly,Nestin tracing also labeled skeletal myocytes,ileal crypt cells,and sparsely marked cerebellar granule neurons.Our findings provide support for endothelial cells as active contributors to adult tissue progenitor pools.This information could be of particular significance for the intravenous delivery of therapeutics to downstream endothelial-derived cellular targets.The animal experiments were approved by the Boise State University Institute Animal Care and Use Committee(approval No.006-AC15-018)on October 31,2018.  相似文献   
990.
ABSTRACT

Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood.  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