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  总被引:1,自引:0,他引:1  
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Emerging methodological research suggests that the World Wide Web (“Web”) is an appropriate venue for survey data collection, and a promising area for delivering behavioral intervention. However, the use of the Web for research raises concerns regarding sample validity, particularly when the Web is used for recruitment and enrollment. The purpose of this paper is to describe the challenges experienced in two different Web‐based studies in which participant misrepresentation threatened sample validity: a survey study and an online intervention study. The lessons learned from these experiences generated three types of strategies researchers can use to reduce the likelihood of participant misrepresentation for eligibility in Web‐based research. Examples of procedural/design strategies, technical/software strategies and data analytic strategies are provided along with the methodological strengths and limitations of specific strategies. The discussion includes a series of considerations to guide researchers in the selection of strategies that may be most appropriate given the aims, resources and target population of their studies. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
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Background: This study examined the degree to which combat‐related guilt mediated the relations between exposure to combat‐related abusive violence and both Posttraumatic Stress Disorder (PTSD) and Major Depressive Disorder (MDD) in Vietnam Veterans. Methods: Secondary analyses were conducted on data collected from 1,323 male Vietnam Veterans as part of a larger, multisite study. Results: Results revealed that combat‐related guilt partially mediated the association between exposure to combat‐related abusive violence and PTSD, but completely mediated the association with MDD, with overall combat exposure held constant in the model. Follow‐up analyses showed that, when comparing those participants who actually participated in combat‐related abusive violence with those who only observed it, combat‐related guilt completely mediated the association between participation in abusive violence and both PTSD and MDD. Moreover, when comparing those participants who observed combat‐related abusive violence with those who had no exposure at all to it, combat‐related guilt completely mediated the association between observation of combat‐related abusive violence and MDD, but only partially mediated the association with PTSD. Conclusions: These findings suggest that guilt may be a mechanism through which abusive violence is related to PTSD and MDD among combat‐deployed Veterans. These findings also suggest the importance of assessing abusive‐violence related guilt among combat‐deployed Veterans and implementing relevant interventions for such guilt whenever indicated. Depression and Anxiety, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
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The current status of percutaneous balloon valvotomy for aortic, subaortic, and mitral stenosis and angioplasty of aortic arch obstructions are reviewed. Results from the authors and other laboratories are discussed in relation to technique and other factors such as patient age and underlying pathology. Current indications for these procedures are reviewed.  相似文献   
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Aortic stenosis surgery in infancy.   总被引:2,自引:0,他引:2  
During the past 14 years, 28 infants (23 males) underwent valvotomy for severe aortic stenosis at the Children's Hospital Medical Center in Boston. The median age was two months and the oldest patient was six months old. Congestive heart failure was present in all but two babies. Preoperatively, the electrocardiogram was abnormal in all, with left ventricular hypertrophy and a strain pattern being present in 19. At cardiac catheterization, the peak systolic ejection gradient (PSEG) ranged from 35-130 mm Hg (median 90 mm Hg). Associated cardiac lesions were present in 39%. Twenty-four infants underwent valvotomy with inflow occlusion. Four patients were operated upon using cardiopulmonary bypass. There were eight early and two late deaths. The 18 survivors have been followed from six months to 11 years (median five years). Only four are symptomatic. Mild aortic regurgitation developed postoperatively in six patients, moderate in one and severe enough to require valve replacement in another one. The electrocardiogram improved postoperatively in 15 patients, but became entirely normal only in one. Five children required a repeat valvotomy for residual stenosis 1-10 years after the original procedure (median four years). At this second operation, the majority of the valves were flexible and noncalcified, and valvotomy was accomplished without difficulty. One child who underwent valve replacement for aortic regurgitation at age two years is well seven years later.  相似文献   
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