Among the possible ionic crosslinkers Ca2+ is most widely used. However, due to its numerous physiological functions, other cations such as Sr2+ may be more suitable depending on application. Because a systematic comparison currently lacking, this work aims compare solutions of CaCl2 and SrCl2 alginate- cellulose-based materials investigate their effects structural biological properties 3D biop...

The effect of activation of protein kinase C by phorbol esters has been studied on the nonmyelinated (C) fibers of the rat vagus nerve. Grease-gap recording at room temperature was used to monitor changes in the resting and action potentials. Effects of phorbol esters on the rate of efflux of 86Rb and 14C-guanidinium were also measured. The active isomer beta-phorbol 12,13-dibutyrate (PDBu), ap...

In Erwinia chrysanthemi 3937, pectate lyase activity mainly results from the cumulative action of five major isoenzymes, PelA to PelE. Comparison of their amino acid sequences revealed two families, PelB-C and PelA-D-E. Molecular cloning permitted expression of the different pel genes in Escherichia coli and the isolation of each Pel independently from the other isoenzymes. We used similar expe...

Voltage-dependent L-type Ca2+ channels select for Ca2+ and other divalent cations by high-affinity Ca2+ binding and ion-ion interactions in the permeation pathway. We have recently identified a series of highly conserved glutamate residues, located within the SS2 segments of each of the four repeats of the human heart Ca2+ channel alpha 1 subunit, as major determinants of ion selectivity of the...

Study of physisorbed and chemisorbed carbon dioxide (CO2) species was carried out on the NaX zeolite modified by cationic exchanges with bivalent cations (Ca2+ Ba2+) temperature-programmed desorption CO2 (CO2-TPD). Others results were obtained infrared to complete study. The this research showed, in physisorption region (213 - 473 K), that increase slightly interactions molecule adsorbents and/...

Comparative studies of structure, magnetism, and magnetoresistance (MR) have been carried out in A-site ordered NdBaMn2O6 (O-NB), disordered (D-NB) NdCaMn2O6 (D-NC). O-NB, where cations, Nd3+ Ba2+ (of different ionic sizes) are arranged periodically, undergoes structural transition with temperature, while no change is present D-NB cations randomly. However, transitions observed D-NC Ca2+ simila...

The thioborate phase Ba7(BS3)4S was synthesized from solid state reaction and its crystal structure determined by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space group C2/c (No. 15) with a = 10.1750(15) A, b = 23.970(4) A, c = 10.1692(15) A, beta = 90.095(2) degrees, and Z = 4. The structure consists of isolated trigonal planar (BS3)3- anions, and isolated S2-...

The influence of modified plasma membrane fatty acid composition on cellular strontium accumulation in Saccharomyces cerevisiae was investigated. Growth of S. cerevisiae in the presence of 1 mM linoleate (18:2) (which results in 18:2 incorporation to approximately 70% of total cellular and plasma membrane fatty acids, with no effect on growth rate) yielded cells that accumulated Sr2+ intracellu...

Three cationic tracers, Sr2+, Co2+ and Cs+ were tested with a modified electromigration device by applying 2V, 3V 4V voltage gradients over an intact Grimsel granodiorite rock sample. An ideal plug-flow model advection-dispersion applied to analyze the breakthrough curves. Matrix characterization C-14-PMMA autoradiography scanning electron microscopy showed that in centimeter scale of rock, int...

Substitution of ionic either anion or cation in a controlled amount into carbonated hydroxyapatite (CHA) structure is one the efficient and safest ways enhancing properties materials. However, most works studied only focused on physical mechanical single substitution. For first time, influence simultaneous ternary substitutions divalent cations porous CHA scaffolds physicochemical, mechanical, ...