Pyrazine derivatives are important class of compounds with diverse biological and cytotoxic activities and clinical applications. In this study, B3 p 86 / 6 – 31 + + G * was used to compute and map the molecular surface electrostatic potentials of a group of substituted amides of pyrazine-2-carboxylic acids to identify common features related to their subsequent cytotoxicities. Several statisti...

the n-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. the quantum theoretical calculations for two crystal structures of n-(2-benzoyl-phenyl) oxalyl (compounds i and ii) were performed by density functional theory (b3lyp method and 6-311+g* basis set). from the optimized structures, geometric paramet...

e-2-arylmethylen-1- tetralones and e-3-phenylme thylene chromanone-4-ones and their derivatives closely related to flavonoids belong to the plant secondary metabolites most investigated recently.the class of flavonoids is an enormous class of plant secondary metabolites having so different pharmacological effects as inhibition of nitric oxide synthasecancer preventive effect or potential impact...

theoretical study of the electronic structure, and nonlinear optical properties (nlo) analysis of 12-crown-4were done using density functional theory (dft) evaluations at the b3lyp/6-311g (d,p) level of theory. the optimized structure is nonlinear compound as indicated from the dihedral angles were presented. the calculated ehomo and elumo energies of 12-crown-4 (12cn4) can be used to explain t...

Electrostatic precipitators (ESP) and fabric filters (FF) are the main air pollution control equipment utilized to clean dust laden fumes from utility boilers. The choice among these systems depends on specific site conditions such as dust characteristics, required efficiency, gas flowrate and temperature. ESP are generally characterized by higher capital investments and lower operating charges...

Calculation of the electrostatic potential of protein-protein complexes has led to the general assertion that protein-protein interfaces display "charge complementarity" and "electrostatic complementarity". In this study, quantitative measures for these two terms are developed and used to investigate protein-protein interfaces in a rigorous manner. Charge complementarity (CC) was defined using ...

The quasineutral limit in the transient quantum drift-diffusion equations in one space dimension is rigorously proved. The model consists of a fourth-order parabolic equation for the electron density, including the quantum Bohm potential, coupled to the Poisson equation for the electrostatic potential. The equations are supplemented with Dirichlet-Neumann boundary conditions. For the proof unif...

We present a methodology to develop coarse-grained lipid models such that electrostatic interactions between the coarse-grained sites can be derived accurately from an all-atom molecular dynamics trajectory and expressed as an effective pairwise electrostatic potential with appropriate screening functions. The reference nonbonded forces from the all-atom trajectory are decomposed into separate ...