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   326篇
  免费   9篇
儿科学   1篇
妇产科学   1篇
基础医学   21篇
口腔科学   2篇
临床医学   172篇
内科学   33篇
皮肤病学   1篇
神经病学   5篇
特种医学   8篇
外科学   42篇
综合类   1篇
预防医学   24篇
药学   7篇
肿瘤学   17篇
  2021年   4篇
  2020年   1篇
  2019年   6篇
  2018年   3篇
  2017年   1篇
  2016年   5篇
  2015年   2篇
  2014年   2篇
  2013年   18篇
  2012年   35篇
  2011年   26篇
  2010年   14篇
  2009年   17篇
  2008年   20篇
  2007年   25篇
  2006年   20篇
  2005年   16篇
  2004年   14篇
  2003年   22篇
  2002年   19篇
  2001年   11篇
  2000年   10篇
  1999年   2篇
  1998年   1篇
  1997年   5篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1971年   2篇
  1970年   1篇
  1969年   3篇
  1968年   3篇
  1966年   2篇
  1964年   1篇
  1963年   2篇
  1962年   1篇
  1958年   1篇
排序方式: 共有335条查询结果,搜索用时 15 毫秒
1.

Background

The purpose of the study was to evaluate the association between fetal echocardiographic measurements and the need for intervention (primary coarctation repair, staged coarctation repair, or catheter intervention) in prenatally diagnosed coarctation of the aorta.

Methods

A single-centre retrospective cohort study (2005-2015) of 107 fetuses diagnosed with suspected coarctation of the aorta in the setting of an apex-forming left ventricle and antegrade flow across the mitral and aortic valves.

Results

Median gestational age at diagnosis was 32 weeks (interquartile range, 23-35 weeks). Fifty-six (52%) did not require any neonatal intervention, 51 patients (48%) underwent a biventricular repair. In univariable analysis, an increase in ascending aorta (AAo) peak Doppler flow velocity (odds ratio [OR], 1.40 [95% confidence interval [CI], 1.05-1.91] per 20 cm/s; P = 0.03) was associated with intervention. No intervention was associated with larger isthmus size (OR, 0.23; P < 0.001), transverse arch diameter (OR, 0.23; P < 0.001), and aortic (OR, 0.72; P = 0.02), mitral (OR, 0.58; P = 0.001), and AAo (OR, 0.53; P < 0.001) z-scores. In multivariable analysis, higher peak AAo Doppler (OR, 2.51 [95% CI, 1.54-4.58] per 20 cm/s; P = 0.001) and younger gestational age at diagnosis (OR, 0.81 [95% CI, 0.70-0.93] per week; P = 0.005) were associated with intervention, whereas a higher AAo z-score (OR, 0.65 [95% CI, 0.43-0.94] per z; P = 0.029) and transverse arch dimension (OR, 0.44 [95% CI, 0.18-0.97]; P = 0.05) decreased the risk of intervention.

Conclusions

In prenatally suspected coarctation, the variables associated with intervention comprised smaller AAo and transverse arch size, earlier gestational age at diagnosis, and the additional finding of a higher peak AAo Doppler.  相似文献   
2.
3.
Traditional tests used in the clinic to identify dementia, such as the mini-mental state examination (MMSE), are useful to identify severe cognitive impairments but might be less sensitive to detect more subtle age-related cognitive changes. Previously, the novel image–novel location (NINL) object recognition test was shown to be sensitive to detect effects of apolipoprotein E4, a risk factor for developing age-related cognitive decline and Alzheimer’s disease, in nondemented elderly. In the present longitudinal study, performance on the MMSE and the NINL tests were compared over a 4-year period. Individual NINL scores over this period were highly correlated. In addition, while MMSE scores did not change over the 4-year period, NINL scores did. In a final testing session of a subset of the participants, NINL scores correlated with logical memory and word recall lists, cognitive tasks used to detect dementia in the clinic, as well as clinical dementia rating scales. These results support that the NINL might be a valuable tool to assess age-related cognitive decline.  相似文献   
4.
Johnston V  Jimmieson NL  Souvlis T  Jull G 《Pain》2007,129(3):311-320
This study investigated the relationship between psychosocial risk factors and (1) neck symptoms and (2) neck pain and disability as measured by the neck disability index (NDI). Female office workers employed in local private and public organizations were invited to participate, with 333 completing a questionnaire. Data were collected on various risk factors including age, negative affectivity, history of previous neck trauma, physical work environment, and task demands. Sixty-one percent of the sample reported neck symptoms lasting greater than 8 days in the last 12 months. The mean NDI of the sample was 15.5 out of 100, indicating mild neck pain and disability. In a hierarchical multivariate logistic regression, low supervisor support was the only psychosocial risk factor identified with the presence of neck symptoms. Similarly, low supervisor support was the only factor associated with the score on the NDI. These associations remained after adjustment for potential confounders of age, negative affectivity, and physical risk factors. The interaction of job demands, decision authority, and supervisor support was significantly associated with the NDI in the final model and this association increased when those with previous trauma were excluded. Interestingly, and somewhat contrary to initial expectations, as job demands increased, high decision authority had an increasing effect on the NDI when supervisor support was low.  相似文献   
5.
Can the Internet be used as a medium to evaluate knee angle?   总被引:1,自引:0,他引:1  
Telemedicine promises to revolutionize medical care delivery in rural and remote areas. The ability to accurately evaluate physical impairment via the Internet is important to the possible future provision of Internet-based physiotherapy. This study evaluated the reliability and validity of assessing knee range of motion via the Internet. Two therapists evaluated knee angle on a single subject via two methods of assessment: the Internet and the traditional method (face-to-face). Nine random positions of the knee were chosen with the principal examiner performing 20 face-to-face and two sets of 20 Internet measures in each position (n=540). The secondary therapist performed Internet assessments only. The Internet connection was established at a readily available speed of 17 kbit/s. The Internet-based goniometer was found to be a valid tool for measuring both knee flexion and extension angles. It was shown to possess both high intra and inter-rater reliability. Difference average plots of the scores verified the consistency of measurement between both modes of assessment. The successful evaluation of the physical outcome measure of knee range of motion via the Internet assists the further development of Internet-based physiotherapy applications.  相似文献   
6.
7.
8.
Whatever the cause, it is extraordinary that dozens of genera of large mammals became extinct during the late Quaternary throughout the Western Hemisphere, including 90% of the genera of the xenarthran suborder Phyllophaga (sloths). Radiocarbon dates directly on dung, bones, or other tissue of extinct sloths place their "last appearance" datum at approximately 11,000 radiocarbon years before present (yr BP) or slightly less in North America, approximately 10,500 yr BP in South America, and approximately 4,400 yr BP on West Indian islands. This asynchronous situation is not compatible with glacial-interglacial climate change forcing these extinctions, especially given the great elevational, latitudinal, and longitudinal variation of the sloth-bearing continental sites. Instead, the chronology of last appearance of extinct sloths, whether on continents or islands, more closely tracks the first arrival of people.  相似文献   
9.
Background: The surge in the incidence of obesity and being overweight demands new options to extend the reach of weight‐loss interventions. Mobile phones provide a medium for reaching large numbers of people in a cost‐effective manner. The present study aimed to explore the potential for weight‐loss interventions to be delivered via mobile phone. Methods: A mixed methods approach was employed. A telephone survey was conducted with 306 randomly selected participants, and 10 focus groups were undertaken with 54 purposively selected participants. The telephone survey comprised questions exploring the nature and acceptability of any potential weight‐loss programme that might be delivered via mobile phones. The focus groups were conducted to explore issues of acceptability in more depth than was possible in the survey. Results: Two‐thirds of participants reported support for a mobile phone weight‐loss intervention, with greater levels of support amongst younger age groups and rural Māori (the indigenous population in New Zealand). Participants liked the idea of ready access to weight‐loss information, and associated feedback and encouragement. The results suggest that interventions would need to include aspects of social support, use tailored and personalised content, and be practical and relevant so that they appeal to consumers. Appropriate methods of providing social support using a mobile phone require further exploration. Conclusions: Mobile phones may provide a novel but acceptable way to deliver a weight‐loss intervention. They have the potential to be automatically personalised and tailored to the needs of the individual, at the same time as being delivered at a population level.  相似文献   
10.
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