Preliminary study on multifunctional bioreactor for in vitro tissue engineering

Abstract not available

Refractive accuracy and visual outcome by self-refraction using adjustable-focus spectacles in young children. A randomized clinical trial

IMPORTANCE: Uncorrected refractive error is the most common cause of vision impairment in children. Most children 12 years or older can achieve visual acuity (VA) of 20/25 or better by self-refraction using adjustable-focus spectacles, but data on younger children are lacking. OBJECTIVE: To assess refractive accuracy, corrected VA, and factors associated with not achieving VA of 20/25 or better among children aged 5 to 11 years performing self-refraction with Adspecs adjustable-focus spectacles (Adaptive Eyecare), compared with noncycloplegic autorefraction and cycloplegic refraction. DESIGN, SETTING, AND PARTICIPANTS: This was a cross-sectional noninferiority trial conducted from September 2, 2015, to December 14, 2017. The study setting was an academic pediatric eye clinic. Children aged 5 to 11 years with uncorrected VA of 20/40 or worse in 1 or both eyes and without systemic or ocular conditions preventing best-corrected VA of 20/25 or better were enrolled. Children who had best-corrected VA worse than 20/25 were excluded. Study data were analyzed from September 2017 to June 2023. EXPOSURES: Children were taught to self-refract with adjustable-focus spectacles. MAIN OUTCOMES AND MEASURES: Spherical equivalent refractive error (using self-refraction, noncycloplegic autorefraction, and cycloplegic refraction) and VA (uncorrected and using self-refraction, noncycloplegic autorefraction, and cycloplegic refraction) for study eyes were evaluated. Potential predictors of failure to achieve VA of 20/25 or better with self-refraction were assessed using logistic regression. RESULTS: A total of 127 consecutive children were enrolled. After exclusions, 112 children (median [IQR] age, 9.0 [8.0-10.3] years; 52 boys [46.4%]) were included in the study. Mean (SD) spherical equivalent refractive power was -2.00 (1.52) diopters (D) for self-refraction, -2.32 (1.43) D for noncycloplegic autorefraction, and -1.67 (1.49) D for cycloplegic refraction. Mean (SD) difference in refractive power between self-refraction and noncycloplegic autorefraction was 0.32 (1.11) D (97.5% 1-sided CI, 0.11 to ∞ D; P  .99). Those failing to achieve best-corrected VA of 20/25 or better with self-refraction had higher astigmatism (odds ratio [OR], 10.6; 95% CI, 3.1-36.4; P < .001) and younger age (OR, 1.5; 95% CI, 1.1-2.2; P = .02). CONCLUSIONS AND RELEVANCE: Self-refraction among children aged 5 to 11 years may result in more myopic power than cycloplegic refraction but not necessarily to a clinically relevant degree. Although the proportion of children achieving VA of 20/25 or better with self-refraction using adjustable-focus spectacles did not differ from cycloplegic refraction, it was less likely among younger children and those with higher astigmatism

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers

Studies of the turbulence-chemistry interaction (TCI) are performed in hypersonic turbulent boundary layers using direct numerical simulation (DNS) flow fields under typical hypersonic conditions representative of blunt-body and slender-body hypersonic vehicles, with super catalytic and noncatalytic wall conditions in pure air. Nondimensional governing parameters, \u27interaction\u27 Damk̈ohler number and relative heat release, are proposed to measure the influence of TCI on flow composition and temperature. Both a priori and posteriori studies are performed to assess the effect of TCI on chemical production rates and mean and turbulence flow characteristics. In addition, an effective approach (called PDF-TS) to estimate the intensity of TCI based on \u27laminar-chemistry\u27 Reynolds averaged Navier-Stokes (RANS) mean flow solutions is presented, which combines an assumed probability density function (PDF) with a temperature fluctuation scaling (TS) and can be used to identify regions where TCI could be potentially important. © 2011 by Lian Duan and M. Pino Martin