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   11292篇
  免费   993篇
  国内免费   40篇
耳鼻咽喉   67篇
儿科学   358篇
妇产科学   260篇
基础医学   1613篇
口腔科学   152篇
临床医学   1477篇
内科学   2267篇
皮肤病学   184篇
神经病学   1258篇
特种医学   203篇
外国民族医学   1篇
外科学   1242篇
综合类   153篇
一般理论   14篇
预防医学   1348篇
眼科学   220篇
药学   730篇
中国医学   17篇
肿瘤学   761篇
  2024年   23篇
  2023年   174篇
  2022年   268篇
  2021年   515篇
  2020年   376篇
  2019年   450篇
  2018年   440篇
  2017年   348篇
  2016年   367篇
  2015年   373篇
  2014年   470篇
  2013年   617篇
  2012年   882篇
  2011年   884篇
  2010年   433篇
  2009年   427篇
  2008年   639篇
  2007年   698篇
  2006年   606篇
  2005年   544篇
  2004年   474篇
  2003年   395篇
  2002年   367篇
  2001年   113篇
  2000年   109篇
  1999年   93篇
  1998年   71篇
  1997年   51篇
  1996年   38篇
  1995年   38篇
  1994年   38篇
  1993年   27篇
  1992年   74篇
  1991年   76篇
  1990年   74篇
  1989年   64篇
  1988年   50篇
  1987年   51篇
  1986年   50篇
  1985年   51篇
  1984年   33篇
  1983年   46篇
  1982年   19篇
  1981年   25篇
  1979年   34篇
  1978年   31篇
  1974年   30篇
  1973年   28篇
  1972年   21篇
  1969年   18篇
排序方式: 共有10000条查询结果,搜索用时 843 毫秒
141.
Restriction factors are a collection of antiviral proteins that form an important aspect of the innate immune system. Their constitutive expression allows immediate response to viral infection, ahead of other innate or adaptive immune responses. We review the molecular mechanism of restriction for four categories of restriction factors; TRIM5, tetherin, APOBEC3G and SAMHD1 and go on to consider how the TRIM5 and TRIMCyp proteins in particular, show promise for exploitation using gene therapy strategies. Such approaches could form an important alternative to current anti-HIV-1 drug regimens, especially if combined with strategies to eradicate HIV reservoirs. Autologous CD4+ T cells or their haematopoietic stem cell precursors engineered to express TRIMCyp restriction factors, and provided in a single therapeutic intervention could then be used to restore functional immunity with a pool of cells protected against HIV. We consider the challenges ahead and consider how early clinical phase testing may best be achieved.  相似文献   
142.

Purpose

A prospective, single-center, single-arm feasibility study evaluated procedural and short-term performance of the Advance Enforcer 35 focal-force percutaneous transluminal angioplasty (PTA) balloon catheter in treating stenoses of mature native arteriovenous (AV) hemodialysis access circuits.

Materials and Methods

Twenty-eight patients undergoing treatment for stenosis of a mature native AV hemodialysis access circuit were enrolled at a single institution. Angiographic assessments of the study lesion were required at baseline and after the procedure. Adjunctive procedures for significant residual stenosis were permitted, and patients had clinical and imaging follow-up for as long as 6 months.

Results

Treatment with the study balloon was effective in reducing the average percent diameter stenosis of the treated lesion from 66.3% (range, 43.8%–93.3%) before the procedure to 23.7% (range, ?6.7% to 51.4%) after the procedure. The average inflation pressure required was 12.3 atm. Only 1 patient required an adjunctive procedure, and all patients could resume normal dialysis following the study procedure. At 3 months, 62.0% of study lesions remained patent, and the 6-month patency rate was 25.1%. Two adverse events associated with the study procedure were reported: access-site hematoma and forearm pain (3.6% each).

Conclusions

The results demonstrate safety of the study balloon in treating AV access stenosis. Nominal-diameter angioplasty was achieved at relatively low pressure in most study patients without the use of adjunctive procedures, and resumption of normal dialysis was achieved for all patients.  相似文献   
143.
144.
Aim: The aim of the paper was to identify changes in the extent and patterns of anabolic steroid use in the United Kingdom to better understand the public health implications within the context of the current health-related evidence base. Methods: Using the two time points between 1995 (prior to legislation changes in the United Kingdom) and 2015, a review of the evidence related to health harms was conducted, in conjunction with needle and syringe programme (NSP) data in Cheshire & Merseyside (UK) relating to anabolic steroid users. Findings: Dramatic increase in the number of anabolic steroid users accessing NSPs, 553 in 1995 to 2446 in 2015, now accounting for 54.9% of clients. With the inclusion of pharmacy NSPs, this rose to 5336 individual anabolic steroid users. Conclusions: Key changes in our knowledge during the 20 years, in particular, in relation to HIV prevalence, changes in the market and patterns of use make anabolic steroid use a public health concern. In the context of increasing numbers of injectors, there is a need for comprehensive interventions.  相似文献   
145.
146.
147.
148.
149.
150.
ObjectivesTo report findings from a systematic review, this article sought to address two related questions. First, how has the practice of UK pediatric cost-utility analyses evolved over time, in particular how are health-related outcomes assessed and valued? Second, how do the methods compare to the limited guidance available, in particular, the National Institute for Health and Care Excellence (NICE) reference case(s)?MethodsElectronic searches of MEDLINE, Embase, and Cochrane databases were conducted for the period May 2004 to April 2012 and the Paediatric Economic Database Evaluation database for the period May 2004 to December 2010. Identified studies were screened by three independent reviewers.ResultsForty-three studies were identified, 11 of which elicit utility values through primary research. A discrepancy was identified between the methods used for outcome measurement and valuation and the methods advocated within the NICE reference case. Despite NICE recommending the use of preference-based instruments designed specifically for children, most studies that were identified had used adult measures. In fact, the measurement of quality-adjusted life-years is the aspect of economic evaluation with the greatest amount of variability and the area that most digressed from the NICE reference case.ConclusionsRecommendations stemming from the review are that all studies should specify the age range of childhood and include separate statements of perspective for costs and effects as well as the reallocation of research funding away from systematic review studies toward good quality primary research measuring utilities in children.  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