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   787篇
  免费   73篇
  国内免费   27篇
耳鼻咽喉   3篇
儿科学   11篇
妇产科学   9篇
基础医学   138篇
口腔科学   14篇
临床医学   92篇
内科学   31篇
皮肤病学   8篇
神经病学   41篇
特种医学   25篇
外科学   45篇
综合类   219篇
预防医学   149篇
眼科学   3篇
药学   63篇
  1篇
中国医学   18篇
肿瘤学   17篇
  2023年   12篇
  2022年   20篇
  2021年   32篇
  2020年   25篇
  2019年   24篇
  2018年   16篇
  2017年   25篇
  2016年   27篇
  2015年   40篇
  2014年   66篇
  2013年   101篇
  2012年   67篇
  2011年   66篇
  2010年   52篇
  2009年   48篇
  2008年   61篇
  2007年   57篇
  2006年   21篇
  2005年   23篇
  2004年   24篇
  2003年   20篇
  2002年   14篇
  2001年   11篇
  2000年   8篇
  1999年   5篇
  1998年   5篇
  1997年   4篇
  1996年   7篇
  1995年   1篇
  1992年   3篇
  1991年   1篇
  1980年   1篇
排序方式: 共有887条查询结果,搜索用时 31 毫秒
21.
22.
23.

Objectives

To determine the efficacy of a web-based transfer training module at improving transfer technique across 3 groups: web-based training, in-person training (current standard of practice), and a waitlist control group (WLCG); and secondarily, to determine subject factors that can be used to predict improvements in transfer ability after training.

Design

Randomized controlled trials.

Setting

Summer and winter sporting events for disabled veterans.

Participants

A convenience sample (N=71) of manual and power wheelchair users who could transfer independently.

Interventions

An individualized, in-person transfer training session or a web-based transfer training module. The WLCG received the web training at their follow-up visit.

Main Outcome Measure

Transfer Assessment Instrument (TAI) part 1 score was used to assess transfers at baseline, skill acquisition immediately posttraining, and skill retention after a 1- to 2-day follow-up period.

Results

The in-person and web-based training groups improved their median (interquartile range) TAI scores from 7.98 (7.18–8.46) to 9.13 (8.57–9.58; P<.01), and from 7.14 (6.15–7.86) to 9.23 (8.46–9.82; P<.01), respectively, compared with the WLCG that had a median score of 7.69 for both assessments (baseline, 6.15–8.46; follow-up control, 5.83–8.46). Participants retained improvements at follow-up (P>.05). A lower initial TAI score was found to be the only significant predictor of a larger percent change in TAI score after receiving training.

Conclusions

Transfer training can improve technique with changes retained within a short follow-up window, even among experienced wheelchair users. Web-based transfer training demonstrated comparable improvements to in-person training. With almost half of the United States population consulting online resources before a health care professional, web-based training may be an effective method to increase knowledge translation.  相似文献   
24.
提出了基于语义网关联数据和本体技术的用户检索方式的转变及基于本体的学科馆员信息服务模型。该模型利用SOA技术为基于语义网的信息服务提供了开放的应用接口,通过建立基于关联数据技术的驱动引擎和知识库,使资源之间具有了语义上的可扩展的关联关系,并搭建了学科馆员平台、医学领域专家平台、学科专业用户平台,学科馆员在医学领域专家的协助下,应用本体模型为医学专业用户提供语义层面的智能化检索服务。  相似文献   
25.
The common carotid artery (CCA) and extracranial internal carotid artery are subject to a wide variety of non-atheromatous pathologies. These entities are often overshadowed in both research and clinical realms by atherosclerotic disease. Nevertheless, non-atherosclerotic disease of the carotid arteries may have profound, even devastating, neurologic consequences. Hence, this review will cover both common and uncommon forms of extracranial carotid artery pathologies in a pictorial format, in order to aid the diagnostician in identifying and differentiating such pathologies.  相似文献   
26.
27.

Background

The World Wide Web allows access to patient/care partner perspectives on the lived experience of dementia. We were interested in how symptoms that care partners target for tracking relate to dementia stage, and whether dementia could be staged using only these online profiles of targeted symptoms.

Objectives

To use clinical data where the dementia stage is known to develop a model that classifies an individual’s stage of dementia based on their symptom profile and to apply this model to classify dementia stages for subjects from a Web-based dataset.

Methods

An Artificial Neural Network (ANN) was used to identify the relationships between the dementia stages and individualized profiles of people with dementia obtained from the 60-item SymptomGuide (SG). The clinic-based training dataset (n=320), with known dementia stages, was used to create an ANN model for classifying stages in Web-based users (n=1930).

Results

The ANN model was trained in 66% of the 320 Memory Clinic patients, with the remaining 34% used to test its accuracy in classification. Training and testing staging distributions were not significantly different. In the 1930 Web-based profiles, 309 people (16%) were classified as having mild cognitive impairment, 36% as mild dementia, 29% as moderate, and 19% as severe. In both the clinical and Web-based symptom profiles, most symptoms became more common as the stage of dementia worsened (eg, mean 5.6 SD 5.9 symptoms in the MCI group versus 11.9 SD 11.3 in the severe). Overall, Web profiles recorded more symptoms (mean 7.1 SD 8.0) than did clinic ones (mean 5.5 SD 1.8). Even so, symptom profiles were relatively similar between the Web-based and clinical datasets.

Conclusion

Symptoms targeted for online tracking by care partners of people with dementia can be used to stage dementia. Even so, caution is needed to assure the validity of data collected online as the current staging algorithm should be seen as an initial step.  相似文献   
28.

Background

The escalating cost of global health care is driving the development of new technologies to identify early indicators of an individual’s risk of disease. Traditionally, epidemiologists have identified such risk factors using medical databases and lengthy clinical studies but these are often limited in size and cost and can fail to take full account of diseases where there are social stigmas or to identify transient acute risk factors.

Objective

Here we report that Web search engine queries coupled with information on Wikipedia access patterns can be used to infer health events associated with an individual user and automatically generate Web-based risk markers for some of the common medical conditions worldwide, from cardiovascular disease to sexually transmitted infections and mental health conditions, as well as pregnancy.

Methods

Using anonymized datasets, we present methods to first distinguish individuals likely to have experienced specific health events, and classify them into distinct categories. We then use the self-controlled case series method to find the incidence of health events in risk periods directly following a user’s search for a query category, and compare to the incidence during other periods for the same individuals.

Results

Searches for pet stores were risk markers for allergy. We also identified some possible new risk markers; for example: searching for fast food and theme restaurants was associated with a transient increase in risk of myocardial infarction, suggesting this exposure goes beyond a long-term risk factor but may also act as an acute trigger of myocardial infarction. Dating and adult content websites were risk markers for sexually transmitted infections, such as human immunodeficiency virus (HIV).

Conclusions

Web-based methods provide a powerful, low-cost approach to automatically identify risk factors, and support more timely and personalized public health efforts to bring human and economic benefits.  相似文献   
29.

Background

Although there is growing evidence of the positive effects of Internet-based patient-provider communication (IPPC) services for both patients and health care providers, their implementation into clinical practice continues to be a challenge.

Objective

The 3 aims of this study were to (1) identify and compare barriers and facilitators influencing the implementation of an IPPC service in 5 hospital units using the Consolidated Framework for Implementation Research (CFIR), (2) assess the ability of the different constructs of CFIR to distinguish between high and low implementation success, and (3) compare our findings with those from other studies that used the CFIR to discriminate between high and low implementation success.

Methods

This study was based on individual interviews with 10 nurses, 6 physicians, and 1 nutritionist who had used the IPPC to answer messages from patients.

Results

Of the 36 CFIR constructs, 28 were addressed in the interviews, of which 12 distinguished between high and low implementation units. Most of the distinguishing constructs were related to the inner setting domain of CFIR, indicating that institutional factors were particularly important for successful implementation. Health care providers’ beliefs in the intervention as useful for themselves and their patients as well as the implementation process itself were also important. A comparison of constructs across ours and 2 other studies that also used the CFIR to discriminate between high and low implementation success showed that 24 CFIR constructs distinguished between high and low implementation units in at least 1 study; 11 constructs distinguished in 2 studies. However, only 2 constructs (patient need and resources and available resources) distinguished consistently between high and low implementation units in all 3 studies.

Conclusions

The CFIR is a helpful framework for illuminating barriers and facilitators influencing IPPC implementation. However, CFIR’s strength of being broad and comprehensive also limits its usefulness as an implementation framework because it does not discriminate between the relative importance of its many constructs for implementation success. This is the first study to identify which CFIR constructs are the most promising to distinguish between high and low implementation success across settings and interventions. Findings from this study can contribute to the refinement of CFIR toward a more succinct and parsimonious framework for planning and evaluation of the implementation of clinical interventions.

ClinicalTrial

Clinicaltrials.gov NCT00971139; http://clinicaltrial.gov/ct2/show/NCT00971139 (Archived by WebCite at http://www.webcitation.org/6cWeqN1uY)  相似文献   
30.

Background

In May 2013, a measles outbreak began in the Netherlands among Orthodox Protestants who often refuse vaccination for religious reasons.

Objective

Our aim was to compare the number of messages expressed on Twitter and other social media during the measles outbreak with the number of online news articles and the number of reported measles cases to answer the question if and when social media reflect public opinion patterns versus disease patterns.

Methods

We analyzed measles-related tweets, other social media messages, and online newspaper articles over a 7-month period (April 15 to November 11, 2013) with regard to topic and sentiment. Thematic analysis was used to structure and analyze the topics.

Results

There was a stronger correlation between the weekly number of social media messages and the weekly number of online news articles (P<.001 for both tweets and other social media messages) than between the weekly number of social media messages and the weekly number of reported measles cases (P=.003 and P=.048 for tweets and other social media messages, respectively), especially after the summer break. All data sources showed 3 large peaks, possibly triggered by announcements about the measles outbreak by the Dutch National Institute for Public Health and the Environment and statements made by well-known politicians. Most messages informed the public about the measles outbreak (ie, about the number of measles cases) (93/165, 56.4%) followed by messages about preventive measures taken to control the measles spread (47/132, 35.6%). The leading opinion expressed was frustration regarding people who do not vaccinate because of religious reasons (42/88, 48%).

Conclusions

The monitoring of online (social) media might be useful for improving communication policies aiming to preserve vaccination acceptability among the general public. Data extracted from online (social) media provide insight into the opinions that are at a certain moment salient among the public, which enables public health institutes to respond immediately and appropriately to those public concerns. More research is required to develop an automatic coding system that captures content and user’s characteristics that are most relevant to the diseases within the National Immunization Program and related public health events and can inform official responses.  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