A mesoscopic model for microscale hydrodynamics and interfacial phenomena: Slip, films, and contact angle hysteresis

We present a model based on the lattice Boltzmann equation that is suitable for the simulation of dynamic wetting. The model is capable of exhibiting fundamental interfacial phenomena such as weak adsorption of fluid on the solid substrate and the presence of a thin surface film within which a disjoining pressure acts. Dynamics in this surface film, tightly coupled with hydrodynamics in the fluid bulk, determine macroscopic properties of primary interest: the hydrodynamic slip; the equilibrium contact angle; and the static and dynamic hysteresis of the contact angles. The pseudo- potentials employed for fluid-solid interactions are composed of a repulsive core and an attractive tail that can be independently adjusted. This enables effective modification of the functional form of the disjoining pressure so that one can vary the static and dynamic hysteresis on surfaces that exhibit the same equilibrium contact angle. The modeled solid-fluid interface is diffuse, represented by a wall probability function which ultimately controls the momentum exchange between solid and fluid phases. This approach allows us to effectively vary the slip length for a given wettability (i.e. the static contact angle) of the solid substrate

Standard vs. Calorie-Dense Immune Nutrition in Haemodynamically Compromised Cardiac Patients: A Prospective Randomized Controlled Pilot Study

Background. The aim of study was to test the hypothesis that early enteral nutrition (EN) with calorie-dense and protein rich enteral formula improves enteral energy and protein delivery in critically ill cardiac patients. Methods. Prospective randomized pilot study of 40 ventilated adult patients undergoing elective cardiac surgery with use of cardiopulmonary bypass receiving inotropic support postoperatively. Patients were to receive either standard isocaloric (1000 Kcal/L and 38 g/L protein) early EN (n = 20) or calorie-dense and protein-rich (1300 Kcal/L and 66.7 g/L protein) early EN (n = 20). Results. The mean time to EN initiation was 27 ± 11 h. Early EN with the calorie-dense formula provided significantly more energy and protein enteral delivery on the 2nd, (p < 0.0001), 5th (p = 0.036), and 7th days (p = 0.024), and was associated with higher levels of prealbumin concentration on the 14th day (0.13 ± 0.01 g/L and 0.21 ± 0.1 g/L; p = 0.04) and significantly increased levels of transferrin on the 3rd, 5th, and 7th day (p < 0.05) after surgery. Conclusion. Present findings support hypothesis that early EN using a calorie-dense and protein rich formula leads to better enteral energy and protein delivery and higher levels of short-lived serum proteins