The cell membrane is a barrier to the passive diffusion of charged molecules due to the chemical properties of the lipid bilayer. Surprisingly, recent experiments have identified processes in which synthetic and biological charged species directly transfer across lipid bilayers on biologically relevant time scales. In particular, amphiphilic nanoparticles have been shown to insert into lipid bi...

The log BB parameter is the logarithm of the ratio of a compound's equilibrium concentrations in the brain tissue versus the blood plasma. This parameter is a useful descriptor in assessing the ability of a compound to permeate the blood-brain barrier. The aim of this study was to develop a Hansch-type linear regression QSAR model that correlates the parameter log BB and the retention time of d...

Conventional iterative solvers for partial differential equations impose strict data dependencies between each solution point and its neighbors. When implemented in OpenMP, they repeatedly execute barrier synchronization in each iterative step to ensure that data dependencies are strictly satisfied. We propose new parallel annotations to support an asynchronous computation model for iterative s...

We have studied the convergence properties of embedded and constrained cluster models of proton transfer in zeolites. We applied density functional theory to describe clusters and ONIOM to perform the embedding. We focused on converging the reaction energy and barrier of the O(1) to O(4) jump in H-Y zeolite as well as vibrational and structural aspects of this jump. We found that using successi...

We propose energy band engineering to enhance tunneling electroresistance (TER) in ferroelectric tunnel junctions (FTJs). predict that an ultrathin dielectric layer with a smaller gap, embedded into barrier layer, acts as switch controlling high and low conductance states of FTJ depending on polarization orientation. Using first-principles modeling based density functional theory, we investigat...

The main function of the skin is to protect the body against exogenous substances. The skin barrier is located in the outermost layer of the skin, the stratum corneum. This layer consists of keratin enriched cells embedded in lipid lamellae. These lamellae form the main barrier for diffusion of substances through the skin. In diseased skin the barrier function is often impaired. For a full unde...

Self-assembled GaInAs quantum dots (QDs) embedded in GaIn(N)As were grown by atmospheric pressure metalorganic vapor phase epitaxy. The dependence of the photoluminescence (PL) properties on the material composition of the barrier layer was investigated. The emission wavelength and intensity of the QDs could be tuned by controlling the indium and nitrogen compositions in the barrier layer. By u...

The primary function of the skin is to act as a barrier against unwanted influences from the environment. The barrier function of the skin is located in the superficial of the skin, the stratum corneum. The stratum corneum consists of dead cells filled with keratin and water, which are embedded in lipid regions. The lipid regions are the only continuous structure in the stratum corneum. For thi...