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   1165篇
  免费   67篇
  国内免费   22篇
耳鼻咽喉   6篇
儿科学   56篇
妇产科学   8篇
基础医学   114篇
口腔科学   16篇
临床医学   174篇
内科学   179篇
皮肤病学   23篇
神经病学   70篇
特种医学   112篇
外科学   107篇
综合类   35篇
预防医学   49篇
眼科学   2篇
药学   248篇
中国医学   1篇
肿瘤学   54篇
  2023年   3篇
  2021年   8篇
  2020年   10篇
  2019年   17篇
  2018年   18篇
  2017年   9篇
  2016年   13篇
  2015年   14篇
  2014年   33篇
  2013年   48篇
  2012年   81篇
  2011年   71篇
  2010年   40篇
  2009年   43篇
  2008年   30篇
  2007年   67篇
  2006年   48篇
  2005年   40篇
  2004年   35篇
  2003年   32篇
  2002年   42篇
  2001年   26篇
  2000年   39篇
  1999年   34篇
  1998年   48篇
  1997年   45篇
  1996年   38篇
  1995年   19篇
  1994年   28篇
  1993年   21篇
  1992年   23篇
  1991年   17篇
  1990年   16篇
  1989年   17篇
  1988年   34篇
  1987年   21篇
  1986年   13篇
  1985年   9篇
  1984年   18篇
  1983年   11篇
  1982年   17篇
  1981年   11篇
  1980年   9篇
  1979年   6篇
  1978年   4篇
  1977年   7篇
  1976年   5篇
  1975年   3篇
  1965年   2篇
  1954年   2篇
排序方式: 共有1254条查询结果,搜索用时 31 毫秒
1.
Current HIV testing guidelines recommend that all adolescents and adults aged 13–64 be routinely screened for HIV in healthcare settings. Sexually transmitted disease (STD) clinic patients represent a population at increased risk for HIV, justifying more frequent risk assessment and testing. This analysis describes missed opportunities for HIV testing among a sample of STD clinic patients to identify areas where HIV testing services may be improved. Secondary analysis was conducted using data from Project AWARE, a randomized trial of 5012 adult patients from 9 STD clinics in the United States, enrolled April–December 2010. HIV testing history, healthcare service utilization, and behavioral risks were obtained through audio computer-assisted self-interview. Missed opportunities for HIV testing, defined as having a healthcare visit but no HIV test in the last 12 months, were characterized by location and frequency. Of 2315 (46.2%) participants not tested for HIV in the last 12 months, 1715 (74.1%) had a missed opportunity for HIV testing. These missed opportunities occurred in both traditional (54.9% at family doctor, 20.3% at other medical doctor visits) and non-traditional (28.5% at dental, 19.0% at eye doctor, 13.9% at correctional facility, and 13.3% at psychology visits) testing settings. Of 53 participants positive for HIV at baseline, 16 (30.2%) had a missed testing opportunity. Missed opportunities for HIV testing were common in this population of STD clinic patients. There is a need to increase routinized HIV screening and expand testing services to a broader range of healthcare settings.  相似文献   
2.

Context

Electrical stimulation (ES) can confer benefit to pressure ulcer (PU) prevention and treatment in spinal cord injuries (SCIs). However, clinical guidelines regarding the use of ES for PU management in SCI remain limited.

Objectives

To critically appraise and synthesize the research evidence on ES for PU prevention and treatment in SCI.

Method

Review was limited to peer-reviewed studies published in English from 1970 to July 2013. Studies included randomized controlled trials (RCTs), non-RCTs, prospective cohort studies, case series, case control, and case report studies. Target population included adults with SCI. Interventions of any type of ES were accepted. Any outcome measuring effectiveness of PU prevention and treatment was included. Methodological quality was evaluated using established instruments.

Results

Twenty-seven studies were included, 9 of 27 studies were RCTs. Six RCTs were therapeutic trials. ES enhanced PU healing in all 11 therapeutic studies. Two types of ES modalities were identified in therapeutic studies (surface electrodes, anal probe), four types of modalities in preventive studies (surface electrodes, ES shorts, sacral anterior nerve root implant, neuromuscular ES implant).

Conclusion

The methodological quality of the studies was poor, in particular for prevention studies. A significant effect of ES on enhancement of PU healing is shown in limited Grade I evidence. The great variability in ES parameters, stimulating locations, and outcome measure leads to an inability to advocate any one standard approach for PU therapy or prevention. Future research is suggested to improve the design of ES devices, standardize ES parameters, and conduct more rigorous trials.  相似文献   
3.
4.

Background

The ability of characteristics to predict first time performance in laparoscopic tasks is not well described. Videogame experience predicts positive performance in laparoscopic experiences but its mechanism and confounding-association with aptitude remains to be elucidated. This study sought to evaluate for innate predictors of laparoscopic performance in surgically naive individuals with minimal videogame exposure.

Methods

Participants with no prior laparoscopic exposure and minimal videogaming experience were recruited consecutively from preclinical years at a medical university. Participants completed four visuospatial, one psychomotor aptitude test and an electronic survey, followed by four laparoscopic tasks on a validated Virtual Reality simulator (LAP Mentor?).

Results

Twenty eligible individuals participated with a mean age of 20.8 (±3.8) years. Significant intra-aptitude performance correlations were present amongst 75% of the visuospatial tests. These visuospatial aptitudes correlated significantly with multiple laparoscopic task metrics: number of movements of a dominant instrument (rs ≥ ?0.46), accuracy rate of clip placement (rs ≥ 0.50) and time taken (rs ≥ ?0.47) (p < 0.05). Musical Instrument experience predicted higher average speed of instruments (rs ≥ 0.47) (p < 0.05). Participant's revised competitive index level predicted lower proficiency in laparoscopic metrics including: pathlength, economy and number of movements of dominant instrument (rs ≥ 0.46) (p < 0.05).

Conclusion

Multiple visuospatial aptitudes and innate competitive level influenced baseline laparoscopic performances across several tasks in surgically naïve individuals.  相似文献   
5.
To what extent access to, and allocation of kidney transplants and survival outcomes in patients aged ≥75 years have changed over time in Europe is unclear. We included patients aged ≥75–84 years (termed older adults) receiving renal replacement therapy in thirteen European countries between 2005 and 2014. Country differences and time trends in access to, and allocation of kidney transplants were examined. Survival outcomes were determined by Cox regression analyses. Between 2005 and 2014, 1392 older adult patients received 1406 transplants. Access to kidney transplantation varied from ~0% (Slovenia, Greece and Denmark) to ~4% (Norway and various Spanish regions) of all older adult dialysis patients, and overall increased from 0.3% (2005) to 0.9% (2014). Allocation of kidney transplants to older adults overall increased from 0.8% (2005) to 3.2% (2014). Seven‐year unadjusted patient and graft survival probabilities were 49.1% (95% confidence interval, 95% CI: 43.6; 54.4) and 41.7% (95% CI: 36.5; 46.8), respectively, with a temporal trend towards improved survival outcomes. In conclusion, in the European dialysis population aged ≥75–84 years access to kidney transplantation is low, and allocation of kidney transplants remains a rare event. Though both are increasing with time and vary considerably between countries. The trend towards improved survival outcomes is encouraging. This information can aid informed decision‐making regarding treatment options.  相似文献   
6.
目的:严重的黏膜损伤是诱发造血干细胞移植后出现并发症的一常见原因,已有证据显示谷氨酰胺能降低接受化疗患儿黏膜炎的发生率。观察谷氨酰胺对异基因外周造血干细胞移植患者并发症及恢复的影响。方法:选择于2002-03/2006-11在河南省血液病研究所接受同胞异基因外周造血干细胞移植的48例血液系统肿瘤患者。所有患者及其家属对治疗和实验均知情同意,并经医院伦理委员会批准。所有患者移植前均处于完全缓解状态,营养中等或良好,心、肝、肾功能正常,将48例患者随机分为标准化全胃肠外营养液组(标准组,n=13)和加用谷氨酰胺的全胃肠外营养液组(谷氨酰胺组,n=35)。待患者中性粒细胞升至1.0×109L-1,且无任何感染指征,进行异基因外周造血干细胞移植。造血干细胞输注后第1天开始给予全胃肠外营养与胃肠外营养联合谷氨酰胺双肽,至中性粒细胞≥1.0×109L-1,且无消化道症状时停用。观察两组患者中性粒细胞恢复时间、出层流室时间以及关于感染、急性移植物抗宿主病等情况有无差异。结果:48例患者均进入结果分析。两组患者营养物质的摄入基本相同,谷氨酰胺组有6例发生黏膜炎,标准组有11例,差异显著(P<0.05);谷氨酰胺组有1例发生严重腹泻,标准组有5例,差异显著(P<0.05);谷氨酰胺组有3例发生临床感染,标准组有7例,差异显著(P<0.05);标准组中性粒细胞≥0.5×109L-1的持续时间短于谷氨酰胺组(P>0.05);谷氨酰胺组抗生素治疗时间及无菌病房居住时间较标准组短(P<0.05);两组急性移植物抗宿主病发生率差异无统计学意义(P>0.05)。结论:添加谷氨酰胺的全胃肠外营养可改善异基因造血干细胞移植患者的营养状态,减少感染及肠损害,减少急性移植物抗宿主病的发生,有利于异基因移植患者恢复。  相似文献   
7.
8.
Recent developments in the study of the structure and function of opioid receptors raise significant challenges for the definition of individual receptor types and the development of a nomenclature that precisely describes isoforms that may subserve different functions in vivo. Presentations at the 2013 meeting of the International Narcotics Research Conference in Cairns, Australia, considered some of the new discoveries that are now unravelling the complexities of opioid receptor signalling. Variable processing of opioid receptor messenger RNAs may lead to the presence of several isoforms of the μ receptor. Each opioid receptor type can function either as a monomer or as part of a homo- or heterodimer or higher multimer. Additionally, recent evidence points to the existence of agonist bias in the signal transduction pathways activated through μ receptors, and to the presence of regulatory allosteric sites on the receptors. This brief review summarizes the recent discoveries that raise challenges for receptor definition and the characterization of signal transduction pathways activated by specific receptor forms.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2  相似文献   
9.
Based on our previous finding of the p.A382T founder mutation in ALS patients with concomitant parkinsonism in the Sardinian population, we hypothesized that the same variant may underlie Parkinson's disease (PD) and/or other forms of degenerative parkinsonism on this Mediterranean island. We screened a cohort of 611 patients with PD (544 cases) and other forms of degenerative parkinsonism (67 cases) and 604 unrelated controls for the c.1144G > A (p.A382T) missense mutation of the TARDBP gene. The p.A382T mutation was identified in nine patients with parkinsonism. Of these, five (0.9 % of PD patients) presented a typical PD (two with familiar forms), while four patients (6.0 % of all other forms of parkinsonism) presented a peculiar clinical presentation quite different from classical atypical parkinsonism with an overlap of extrapyramidal–pyramidal–cognitive clinical signs. The mutation was found in eight Sardinian controls (1.3 %) consistent with a founder mutation in the island population. Our findings suggest that the clinical presentation of the p.A382T TARDBP gene mutation may include forms of parkinsonism in which the extrapyramidal signs are the crucial core of the disease at onset. These forms can present PSP or CBD-like clinical signs, with bulbar and/or extrabulbar pyramidal signs and cognitive impairment. No evidence of association has been found between TARDBP gene mutation and typical PD.  相似文献   
10.
IntroductionHuman error is the major causal factor of industrial and transportation accidents and healthcare is not immune to the effects of human error. Medical error can be defined as the failure of the planned action to be completed as intended or the use of a wrong plan to achieve an aim.AimThe objective of this literature review was to explore the practices of medical error management and disclosure by surgical trainees and to examine how to better prepare and educate the surgeons of tomorrow.MethodsPubMed was searched to identify available literature. Preliminary search criteria included medical error and junior doctors, management and prevention of medical error.ResultsFifty-two papers were included for review. Medical error is common and junior doctors are more vulnerable to err. Most serious errors occur in the emergency department, operating rooms and the intensive care unit. Improvements in patient safety result primarily from organizational and individual learning, particularly with reference to trainee doctors who present an enhanced level of risk.ConclusionJunior doctors are a unique population, with a higher propensity to medical error. A transition from the current culture of ‘name, blame and shame’ is required. We need to ensure that the ‘learning moment’ is seized and that mistakes are learned from and not simply forgotten. Surgery has an opportunity to learn from high risk-industries and incorporate human factors training, into surgical training programs in order to better manage and prevent medical error.  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