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   1457450篇
  免费   120834篇
  国内免费   6462篇
耳鼻咽喉   18776篇
儿科学   47210篇
妇产科学   39412篇
基础医学   201829篇
口腔科学   40308篇
临床医学   131009篇
内科学   299877篇
皮肤病学   35424篇
神经病学   122908篇
特种医学   60629篇
外国民族医学   283篇
外科学   228584篇
综合类   32079篇
现状与发展   2篇
一般理论   451篇
预防医学   113445篇
眼科学   30887篇
药学   102247篇
  5篇
中国医学   2398篇
肿瘤学   76983篇
  2018年   16016篇
  2017年   12873篇
  2016年   15640篇
  2015年   16704篇
  2014年   22612篇
  2013年   34602篇
  2012年   42491篇
  2011年   45950篇
  2010年   28317篇
  2009年   26532篇
  2008年   43540篇
  2007年   46340篇
  2006年   47184篇
  2005年   45695篇
  2004年   43504篇
  2003年   42694篇
  2002年   40577篇
  2001年   70368篇
  2000年   73375篇
  1999年   59705篇
  1998年   17941篇
  1997年   16021篇
  1996年   16787篇
  1995年   16885篇
  1994年   15737篇
  1993年   14764篇
  1992年   47752篇
  1991年   46318篇
  1990年   44523篇
  1989年   42383篇
  1988年   39209篇
  1987年   38603篇
  1986年   36297篇
  1985年   35275篇
  1984年   26962篇
  1983年   22607篇
  1982年   14367篇
  1981年   12926篇
  1980年   12182篇
  1979年   23972篇
  1978年   17480篇
  1977年   14807篇
  1976年   13544篇
  1975年   14087篇
  1974年   16458篇
  1973年   15702篇
  1972年   14416篇
  1971年   13304篇
  1970年   12108篇
  1969年   11315篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
Purpose

This paper describes the design of a theory-informed pragmatic intervention for adolescent perinatal depression in primary care in Nigeria.

Methods

We conducted Focus Group Discussions (FGDs) among 17 adolescent mothers and 25 maternal health care providers with experience in the receipt and provision of care for perinatal depression. The Consolidated Framework for Implementation Research (CFIR) was used to systematically examine the barriers and facilitators affecting adolescent mothers' use of an existing intervention package for depression. The Theoretical Domain Framework (TDF) and the Capability, Opportunity, Motivation, Behaviour (COM-B) model were used to analyze the results of the data across the five CFIR domains.

Results

FGD analysis revealed that care providers lacked knowledge on approaches to engage young mothers in treatment. Young mothers had poor treatment engagement, low social support, and little interest in parenting. A main characteristic of the newly designed intervention is the inclusion of age-appropriate psychoeducation supported with weekly mobile phone calls, to address treatment engagement and parenting behaviours of young mothers. Also in the outer setting, low social support from relatives was addressed with education, “as need arises” phone calls, and the involvement of "neighborhood mothers”. In the inner settings, care providers’ behaviour is addressed with training to increase their capacity to engage young mothers in treatment.

Conclusion

A theory-based approach helped develop an age-appropriate intervention package targeting depression and parenting skills deficit among perinatal adolescents in primary maternal care and in which a pragmatic use of mobile phone was key.

  相似文献   
14.
15.
16.
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric plasma equilibrium problem. The proposed method, obtained from an improvement of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium problem in unbounded domains by discretizing only the plasma region; the external conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github. om/matteobonotto/ FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against experimental data from RFX-mod device, and numerical equilibria of an ITER-like device.  相似文献   
17.
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.  相似文献   
18.
19.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
20.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  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