Acinus-on-a-chip: a microfluidic platform for pulmonary acinar flows.

Convective respiratory flows in the pulmonary acinus and their influence on the fate of inhaled particles are typically studied using computational fluid dynamics (CFD) or scaled-up experimental models. However, experiments that replicate several generations of the acinar tree while featuring cyclic wall motion have not yet been realized. Moreover, current experiments generally capture only flow dynamics, without inhaled particle dynamics, due to difficulties in simultaneously matching flow and particle dynamics.

Deformation and breakup of micro- and nanoparticle stabilized droplets in microfluidic extensional flows.

Using a microfluidic flow-focusing device, monodisperse water droplets in oil were generated and their interface populated by either 1 μm or 500 nm amine modified silica particles suspended in the water phase. The deformation and breakup of these Pickering droplets were studied in both pure extensional flow and combined extensional and shear flow at various capillary numbers using a microfluidic hyperbolic contraction. The shear resulted from droplet confinement and increased with droplet size and position along the hyperbolic contraction.

Nocturic frequency is related to severity of obstructive sleep apnea, improves with continuous positive airways treatment.

Objective: The purpose of this study was to determine the relationship between nocturia and obstructive sleep apnea (OSA), and the effect of continuous positive airways pressure (CPAP) therapy on nocturic frequency.

Study Design: This was a retrospective review of sleep studies including patients with and without evidence of OSA, before and during CPAP treatment (where relevant). Chi-squared tests compared nocturia prevalence according to sleep diagnosis, logistic regression determined predictors of nocturia, and regression analyses determined predictors of nocturic frequency.