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   5367篇
  免费   454篇
  国内免费   10篇
耳鼻咽喉   27篇
儿科学   192篇
妇产科学   184篇
基础医学   584篇
口腔科学   68篇
临床医学   945篇
内科学   1049篇
皮肤病学   46篇
神经病学   366篇
特种医学   73篇
外国民族医学   1篇
外科学   746篇
综合类   79篇
一般理论   7篇
预防医学   743篇
眼科学   102篇
药学   350篇
中国医学   6篇
肿瘤学   263篇
  2023年   23篇
  2022年   41篇
  2021年   106篇
  2020年   54篇
  2019年   80篇
  2018年   106篇
  2017年   102篇
  2016年   108篇
  2015年   124篇
  2014年   151篇
  2013年   227篇
  2012年   326篇
  2011年   366篇
  2010年   197篇
  2009年   183篇
  2008年   318篇
  2007年   393篇
  2006年   416篇
  2005年   325篇
  2004年   294篇
  2003年   257篇
  2002年   266篇
  2001年   94篇
  2000年   95篇
  1999年   76篇
  1998年   39篇
  1997年   35篇
  1996年   44篇
  1995年   24篇
  1994年   26篇
  1993年   25篇
  1992年   39篇
  1991年   60篇
  1990年   55篇
  1989年   64篇
  1988年   44篇
  1987年   37篇
  1986年   59篇
  1985年   47篇
  1984年   41篇
  1983年   46篇
  1982年   32篇
  1981年   23篇
  1979年   35篇
  1978年   26篇
  1977年   30篇
  1975年   25篇
  1974年   22篇
  1973年   35篇
  1972年   20篇
排序方式: 共有5831条查询结果,搜索用时 15 毫秒
991.
992.
993.
Following the discovery of the HFE gene in 1996 and its linkage to the iron overload disorder hereditary hemochromatosis (HH) there have been profound developments in our understanding of the pathogenesis of the biochemical and clinical manifestations of a number of iron overload disorders. This article provides an update of recent developments and key issues relating to iron homeostasis and inherited disorders of iron overload, with emphasis on HFE-related HH, and is based on the content of the American Association for the Study of Liver Diseases Single-Topic Conference entitled "Hemochromatosis: What has Happened After HFE?" which was held at the Emory Convention Center in Atlanta, September 7-9, 2007.  相似文献   
994.
995.
In 2002, a regional consortium was created for schools and colleges of pharmacy in Georgia and Alabama to assist experiential education faculty and staff members in streamlining administrative processes, providing required preceptor development, establishing a professional network, and conducting scholarly endeavors. Five schools and colleges of pharmacy with many shared experiential practice sites formed a consortium to help experiential faculty and staff members identify, discuss, and solve common experience program issues and challenges. During its 5 years in existence, the Southeastern Pharmacy Experiential Education Consortium has coordinated experiential schedules, developed and implemented uniform evaluation tools, coordinated site and preceptor development activities, established a work group for educational research and scholarship, and provided opportunities for networking and professional development. Several consortium members have received national recognition for their individual experiential education accomplishments. Through the activities of a regional consortium, members have successfully developed programs and initiatives that have streamlined administrative processes and have the potential to improve overall quality of experiential education programs. Professionally, consortium activities have resulted in 5 national presentations.  相似文献   
996.
Atrial fibrillation (AF) is the most common rhythm disturbance in medical practice and represents a very expensive health problem. AF can be managed with the prevention of thromboembolism and either a rate control of rhythm strategy. As both strategies have important limitations, probably a preventative strategy in patients at risk of developing arrhythmia can be a more attractive option. The renin-angiotensin system (RAS) seems to be involved in the genesis of arrhythmia by the following two mechanisms: 1. the induction of atrial fibrosis and structural remodelling by mitogen-activated protein kinase (MAPK) expression and reduction of collagenase activity; 2. the induction of electrical remodelling by shortening of the atrial effective refractory period (AERP) and of the action potential duration. For these reasons it has been hypothesized that angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin-II receptor blockers (ARBs) may play a role in preventing AF recurrence. The aim of the present review was to analyse evidence supporting the usefulness of RAS inhibition in patients with AF in order to focus on which specific subset of patients it would most favour. After reviewing the literature, we conclude that, although many studies and meta-analysis have supported the advantage of RAS block in preventing AF recurrence, it is premature to recommend the use of ACE-Is and ARBs specifically for the prevention of AF. However we believe that as these drugs are safe and manageable, they should be considered the drugs of choice in patients with AF and coexisting clinical conditions such as hypertension, coronary disease, heart failure and diabetes mellitus.  相似文献   
997.
Pain has been associated with increased risk for mortality in some studies. We analyzed data from a cohort study [HIV-longitudinal interrelationships of viruses and ethanol (HIV-LIVE)] of HIV-infected persons with alcohol use disorders enrolled 2001–2003 to explore whether reporting moderate or greater pain interference was associated with mortality. The main independent variable was pain that at least moderately interfered with work based on a single question from the SF-12. Primary analyses dichotomized at “moderately” or above. Cox proportional hazards models assessed the association between pain interference and death adjusting for demographics, substance use, CD4 count, HIV viral load and co-morbidities. Although significant in unadjusted models (HR = 1.58 (95 % CI 1.03–2.41; p value = 0.04)), after adjusting for confounders, ≥moderate pain interference was not associated with an increased risk of death [aHR = 1.30 (95 % CI 0.81–2.11, p value = 0.28)]. Among HIV-infected persons with alcohol use disorders, we did not detect a statistically significant independent association between pain interference and risk of death after adjustment for potential confounders.  相似文献   
998.
The objective of this study was to investigate an apparent increase in linezolid-nonsusceptible staphylococci and enterococci following a laboratory change in antimicrobial susceptibility testing from disk diffusion to an automated susceptibility testing system. Isolates with nonsusceptible results (n = 27) from Vitek2 were subjected to a battery of confirmatory testing which included disk diffusion, Microscan broth microdilution, Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution, gradient diffusion (Etest), 23S rRNA gene sequencing, and cfr PCR. Our results show that there is poor correlation between methods and that only 70 to 75% of isolates were confirmed as linezolid resistant with alternative phenotypic testing methods (disk diffusion, Microscan broth microdilution, CLSI broth microdilution, and Etest). 23S rRNA gene sequencing identified mutations previously associated with linezolid resistance in 16 (59.3%) isolates, and the cfr gene was detected in 3 (11.1%) isolates. Mutations located at positions 2576 and 2534 of the 23S rRNA gene were most common. In addition, two previously undescribed variants (at positions 2083 and 2345 of the 23S rRNA gene) were also identified and may contribute to linezolid resistance.  相似文献   
999.
In the previous study, we constructed an expression vector carrying the anti-EGFRvIII scFv antibody gene with VH-linker-VL orientation. The proteins were successfully produced in the periplasmic space of Escherichia coli. In this study, we substituted the inserted DNA with VL-linker-VH orientation of the anti-EGFRvIII scFv gene and analyzed its expression in E. coli. The DNA fragment was amplified from its cloning vector (pTz-rscFv), subsequently cloned into a previous expression vector containing the pelB signal sequence and his-tag, and then transformed into E. coli TOP10. The recombinant plasmids were characterized by restriction, PCR, and DNA sequencing analyses. The new anti-EGFRvIII scFv antibody proteins have been successfully expressed in the periplasmic compartment of E. coli Nico21(DE3) using 0.1 mM final concentration of IPTG induction. Total proteins, soluble periplasmic and cytoplasmic proteins, solubilized inclusion bodies, and extracellular proteins were analyzed by SDS-PAGE and Western Blot analyses. The results showed that soluble scFv proteins were found in all fractions except from the cytoplasmic space.  相似文献   
1000.

Purpose

Patient-reported data are playing an increasing role in health care. In oncology, data from quality of life (QoL) assessment tools may be particularly important for those with limited survival prospects, where treatments aim to prolong survival while maintaining or improving QoL. This paper examines the use and impact of using QoL measures on health care of cancer patients within a clinical setting, particularly those with brain cancer. It also examines facilitators and challenges, and provides implications for policy and practice.

Design

We conducted a systematic literature review, 15 expert interviews and a consultation at an international summit.

Results

The systematic review found no relevant intervention studies specifically in brain cancer patients, and after expanding our search to include other cancers, 15 relevant studies were identified. The evidence on the effectiveness of using QoL tools was inconsistent for patient management, but somewhat more consistent in favour of improving patient–physician communication. Interviews identified unharnessed potential and growing interest in QoL tool use and associated challenges to address.

Conclusion

Our findings suggest that the use of QoL tools in cancer patients may improve patient–physician communication and have the potential to improve care, but the tools are not currently widely used in clinical practice (in brain cancer nor some other cancer contexts) although they are in clinical trials. There is a need for further research and stakeholder engagement on how QoL tools can achieve most impact across cancer and patient contexts. There is also a need for policy, health professional, research and patient communities to strengthen information exchange and debate, support awareness raising and provide training on tool design, use and interpretation.
  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