K(+) channels exhibit strong selectivity for K(+) ions over Na(+) ions based on electrophysiology experiments that measure ions competing for passage through the channel. During this conduction process, multiple ions interact within the region of the channel called the selectivity filter. Ion selectivity may arise from an equilibrium preference for K(+) ions within the selectivity filter or fro...

The propylene production with 1-butanol co-feeding for methanol in relation to propylene process (MTP) at 440-490 ̊C temperature range and at 0.9-15 hr-1 WHSV range over H-ZSM-5 zeolite catalyst is assessed in a isothermal fixed-bed reactor. The feedings here are of: pure 1-butanol, pure methanol and a 1-butanol and methanol mixture. The effect of 1-butanol co-feeding on selectivity of propylene...

In this work, the main aspects regarding the permeation of mixtures containing CO2 and permanent gases such as H2 , N2 and CH4 through zeolite membranes have been investigated, focusing on the description of the mass transport mechanisms taking place inside the pores. First, a brief overview about the performance of the main zeolite membranes used in gas separation (e.g. DDR, CHA, AEI, FAU, etc...

A new series of imidazo[2,1-b]thiazole analogs containing a methyl sulfonyl COX-2 pharmacophore was synthesized and evaluated for their COX-2 inhibitory activity. According to in-vitro COX-1/COX-2 inhibition data, all compounds (6a-g) were selective inhibitors of COX-2 isoenzyme with IC50 values in the highly potent 0.08-0.16 mM range. These results indicated that both potency and selectivity o...

The series of mono-metallic and bi-metallic catalysts have been prepared by impregnatingwith solutions containing compound of H2PtC15,NbC15 and lml HC1 (0.1 mol). The activityand selectivity of the catalysts have been determined under conditions at 450-500°C, 15-30atm. Molar ratio H2/C7H16=5 and VVH=1.5/h for converting n-heptane. Under theseexperimental conditions it has been established that ...

Unsubstituted phthalocyanines of Co, Fe and Mn supported on zinc oxide nanoparticles were prepared and were well characterized with X-ray diffraction and scanning electron microscopy. The oxidation of alcohols with tert-butylhydroperoxide, in the presence of metallophthalocyanines supported on zinc oxide nanoparticles was investigated. These MPc/ZnO nanocomposites were effective catalysts for t...

Selectivity of a number of vermiculites, montmorillonites and micas for K and Cs ions was determined by sorption of these ions from equilibrium solutions of diverse concentrations. The selectivity coefficients were related to the layer charge density and the area of the frayed edges in layer silicates. Montmorillonites had the smallest selectivity for the two ions, while biotite and illite had ...