An exact solution of the time-dependent Dirac equation for ionization and pair production induced by ultrarelativistic heavy ion collisions is presented. Exact transition probabilities, equivalent to those that would be obtained in an untruncated basis coupled channels calculation, are presented. Exact bound-electron positron pair production probabilities are calculated to be mostly smaller tha...

Purpose: To develop a new and fully validated ion-pair spectrophotometric method for the determination of duloxetine hydrochloride (DX). Methods: Ion-pair spectrophotometric method was employed for the determination of duloxetine hydrochloride (DX) in bulk and pharmaceutical formulations using acidic dye methyl orange (MO) as ion-pairing agent at pH 4 (phthalate buffer). The yellow ion-pair com...

Molecular simulation of infinitely dilute NaCl aqueous solutions are performed to study the NarCl ion Ž . pairing in a polarizable and a non-polarizable solvent at supercritical conditions. The simple point charge SPC , the Pettitt–Rossky and the Fumi–Tosi models for the water–water, the ion–water, and the ion–ion interactions are used in the determination of the degree of dissociation, its tem...

in recent years, ionic liquids have been used in pharmaceutical processes. therefore, having a deep insight into the ion association behavior of ionic liquids in the presence of a drug is of particular importance. so, in this work, the molar conductivities of the ionic liquids, 1-alkyl-3-methylimidazolium bromide, [cnmim]br (n = 4, 6 and 8) in various concentrations of aspirin (asa) in acetonit...

Ion selectivity is critical for the biological functions of voltage-dependent cation channels and is achieved by specific ion binding to a pore region called the selectivity filter. In voltage-gated K+, Na+ and Ca2+ channels, the selectivity filter is formed by a short polypeptide loop (called the H5 or P region) between the fifth and sixth transmembrane segments, donated by each of the four su...

A simple and sensitive extraction-spectrophotometric method for rapid and accurate determination of benzocaine in pure and dosage forms was developed. Benzocaine was effectively extracted as a 1:1 ion pair complex with dicyclohexyl-18-crown-6 and calmagite in acidic media into chloroform, followed by spectrophotometric determination at 486 nm. Molar absorptivity of the ternary complex at this w...