The effect of Sr2+ substitution on the morphology, crystal structure, and optical properties of double perovskite oxide Ba2-xSrxZnWO₆ (x = 0.00, 0.25, 0.50, 0.75, 1.00) were investigated. Scanning electronic microscopy demonstrated that all samples have similar microstructure morphology but differ in the range of grain sizes. X-ray diffraction measurements indicated that these materials crystal...

Transmitter release and synaptic vesicle exo- and endocytosis during high-frequency stimulation (20 pulses/s) in the extracellular presence of different bivalent cations (Ca(2+), Sr2+ or Ba2+) were studied in frog cutaneous pectoris nerve-muscle preparations. It was shown in electrophysiological experiments that almost only synchronous transmitter release was registered in a Ca(2+)-containing s...

Ternary carbodiimides, Ba1-xSrxNCN (x ​= ​0, 0.1, 0.2, 0.5, 0.8, and 1.0) were prepared by an ammonolysis reaction with a (Ba,Sr)CO3 precursor obtained polymerized complex method. A new orthorhombic carbodiimide was at x ​0.1. It coexists SrNCN-type solid solutions between ​0.2 0.5. The crystal structure of Ba0.9Sr0.1NCN determined using single-crystal X-ray powder neutron diffraction data, fou...

A series of molybdate, MoO4(2-), salts have been studied using solid-state 95Mo NMR spectroscopy at applied magnetic field strengths of 11.75, 17.63 and 21.14 T. In contrast to previous investigations, the principal components of the Mo shielding and EFG tensors have been obtained, as well as their relative orientations. At the fields employed, the anisotropic Mo shielding and quadrupolar inter...

Action potentials were recorded from chick embryo atrial muscle cells bathed in Tyrode's solution. Tetrodotoxin (TTX), 3.1 muM, was added to block the early, transient, Na+-dependent conductance system. Rectangular stimuli were used to evoke action potentials the peak amplitude (Ep) of which depend on the external concentration of divalent cations, [Me2+]0. The relationship between Ep and [Me2+...

The role of divalent cations in the mechanism of pyrophosphate-activated, template-directed oligoribonucleotide ligation has been investigated. The dependence of the reaction rate on Mg2+ concentration suggests a kinetic scheme in which a Mg2+ ion must bind before ligation can proceed. Mn2+, Ca2+, Sr2+, and Ba2+ can also catalyze the reaction. Although Pb2+ and Zn2+ do not catalyze the reac...

The article presents the research results dealing with influence of such natural minerals as flint and shungite in relation to following water parameters pH, TDS, conductivity, cations (NH4+, K+, Na+, Mg2+, Sr2+, Ba2+, Ca2+) anions (Cl−, SO42−, NO3−, F−, СО32−). It was found that crushed added more significantly increases hydrogen index if compared sedimentation. Simultaneously total mineraliza...

The effect of repetitive stimulation on synaptic transmission was studied in the isolated superior cervical ganglion of the rabbit under conditions of reduced quantal content. Excitatory postsynaptic potentials (EPSP) were recorded with the sucrose gap technique to obtain estimates of transmitter release. Four components of increased transmitter release, with time constants of decay similar to ...