a palladium composite membrane was prepared via electroless plating technique using organic-inorganic method during activation process. the ceramic support surface was modified by two tio2-boehmite and one γ-alumina layers to avoid pd penetration in support pores. thin and defect-free pd composite membrane was obtained by creating a relative smoothness on the ceramic support and using pd nanopa...

Commercial carbon nanotubes (CNTs) and carbon nanofibers (CNFs) modified in various ways at the surface have been used as supports for gold nanoparticles (AuNPs) in order to study their influence on the activity/selectivity of catalysts in the aqueous oxidation of alcohol. Particularly oxidative treatment was used to introduce carboxylic functionalities, whereas subsequent treatment with NH3 at...

An extensive study of Higher Alcohols Synthesis (HAS) from syngas using alkalized MoS2 catalysts supported on Carbon Nanotubes (CNTs) is reported. Up to 30wt.% of Mo and 8wt.% K are added to the CNTs by impregnation method. The catalysts were characterized by different methods and the performance of the catalysts was assessed in a micro-reactor. TEM images showed that mo...

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 permeation pathway of the Na channel is formed by asymmetric loops (P segments) contributed by each of the four domains of the protein. In contrast to the analogous region of K channels, previously we (Yamagishi, T., M. Janecki, E. Marban, and G. Tomaselli. 1997. Biophys. J. 73:195-204) have shown that the P segments do not span the selectivity region, that is, they are accessible only from...

To trigger action potentials in neurons, most investigators use electrical or chemical stimulation. Here we describe an optical stimulation method based on semi-synthetic light-activated ion channels. These SPARK (synthetic photoisomerizable azobenzene-regulated K(+)) channels consist of a synthetic azobenzene-containing photoswitch and a genetically modified Shaker K(+) channel protein. SPARK ...

A liquid membrane containing diethylene glycol monobutyl ether (2) shows specificity for K ion in transport while diethylene glycol dibutyl ether (1) was selective for Na over K . As an extractant, ligand 2 exhibited pronounced extraction selectivity for K over Na in comparison with ligand 1