ABSTRACT
Giant unilamellar vesicles (GUVs) are model cell-sized systems that have broad applications including drug delivery, analysis of membrane biophysics, and synthetic reconstitution of cellular machineries. Although numerous methods for the generation of free-floating GUVs have been established over the past few decades, only a fraction have successfully produced uniform vesicle populations both from charged lipids and in buffers of physiological ionic strength. In the method described here, we generate large numbers of free-floating GUVs through the rehydration of lipid films deposited on soft polyacrylamide (PAA) gels. We show that this technique produces high GUV concentrations for a range of lipid types, including charged ones, independently of the ionic strength of the buffer used. We demonstrate that the gentle hydration of PAA gels results in predominantly unilamellar vesicles, which is in contrast to comparable methods analyzed in this work. Unilamellarity is a defining feature of GUVs and the generation of uniform populations is key for many downstream applications. The PAA method is widely applicable and can be easily implemented with commonly utilized laboratory reagents, making it an appealing platform for the study of membrane biophysics.
ABSTRACT
INTRODUCTION: A large proportion of children and adolescents participate in organised sport, making community sports clubs a promising setting to support healthy behaviours. To date, however, there have been few interventions conducted in junior sports clubs that have targeted health-promoting practices. The primary aim of this pilot study is to assess the potential effectiveness of an intervention to implement health-promoting policies and practices in junior sporting clubs targeting alcohol and tobacco practices, healthy food and beverage availability, and physical activity via participation in sport. A secondary outcome is to assess the impact of such strategies on child exposure to alcohol and tobacco use at the club, purchasing behaviours by/for children at the club canteen and child sports participation opportunities. METHODS AND ANALYSIS: The study will employ a cluster randomised controlled trial design and be conducted in metropolitan and regional areas of two Australian states. Randomisation will occur at the level of the football league. Community football clubs with over 40 junior players (players under 18 years) within each league will be eligible to participate. The intervention will be developed based on frameworks that consider the social, cultural and environmental factors that influence health behaviours. Intervention clubs will be supported to implement 16 practices targeting alcohol management, tobacco use, nutrition practices, new player recruitment activity, equal participation for players and the development of policies to support these practices. Trained research staff will collect outcome data via telephone interviews at baseline and follow-up. Interviews will be conducted with both club representatives and parents of junior players. ETHICS AND DISSEMINATION: The study has been approved by the University of Newcastle Human Research Ethics Committee (H-2013-0429). The results of the study will be disseminated via peer-reviewed publications and presentations at conferences. TRIAL REGISTRATION NUMBER: ACTRN12617001044314; Pre-results.
Subject(s)
Environment , Health Behavior , Health Promotion/methods , Organizational Policy , Soccer , Adolescent , Australia , Child , Female , Humans , Linear Models , Male , Pilot Projects , Research Design , Youth SportsABSTRACT
INTRODUCTION: Cardiac resynchronization therapy (CRT) efficacy trials to date used atrial-synchronous biventricular pacing wherein there is no or minimal atrial pacing. However, bradycardia and chronotropic incompetence are common in this patient population. This trial was designed to evaluate the effect of atrial support pacing among heart failure patients receiving a CRT defibrillator. METHODS AND RESULTS: PEGASUS CRT was a multicenter, 3-arm, randomized study. At 6 weeks, patients were randomized to DDD mode at a lower rate of 40 bpm (DDD-40; control arm), or one of the following 2 treatment arms: DDD-70, or DDDR-40. The primary endpoint was a clinical composite endpoint that included all-cause mortality, heart failure events, NYHA functional class, and patient global self-assessment. Subjects were classified as improved, unchanged, or worsened at 12 months. There were 1,433 patients randomized, of whom 66% were male, mean age was 67 ± 11 years, and mean left ventricular ejection fraction was 23 ± 7%. The average follow-up time was 10.5 ± 3.5 months and 1,309 patients contributed to the primary endpoint. No significant differences were observed in the composite endpoint between either of the 2 treatment arms compared to the control arm (P>0.05 for both comparisons). Additionally, there were no differences among the groups in mortality or heart failure events. CONCLUSION: In advanced heart failure patients treated with CRT, atrial support pacing did not improve clinical outcomes compared to atrial tracking. However, atrial pacing did not adversely affect mortality or heart failure events.
