Estimation of the Sorption Activity of Silver Nanoparticles on Biodegradable Fibers of Natural and Artificial Origin

Russian Physics Journal - The specific features of the sorption activity of silver nanoparticles (AgNPs) on biodegradable polymers of natural (collagen) and artificial (polyamide 6.6) origin have...     

Influence on the Energy of the Covalent Bond of the Isotopic Composition of its Nuclei

Russian Physics Journal - Based on the classical quantum-mechanical approach, the physical mechanism of isotope fractionation is proposed associated with the predominance of a certain number of...     

Electrophysiological Activity and Survival Rate of Rats Nervous Tissue Cells Depends on D/H Isotopic Composition of Medium

The deuterium content modification in an organism has a neuroprotective effect during the hypoxia model, affecting anxiety, memory and stress resistance. The aim of this work was to elucidate the possible mechanisms of the medium D/H composition modification on nerve cells. We studied the effect of an incubation medium with a 50 ppm deuterium content compared to a medium with 150 ppm on: (1) the activity of Wistar rats’ hippocampus CA1 field neurons, (2) the level of cultured cerebellar neuron death during glucose deprivation and temperature stress, (3) mitochondrial membrane potential (MMP) and the generation of reactive oxygen species in cultures of cerebellar neurons. The results of the analysis showed that the incubation of hippocampal sections in a medium with a 50 ppm deuterium reduced the amplitude of the pop-spike. The restoration of neuron activity was observed when sections were returned to the incubation medium with a 150 ppm deuterium content. An environment with a 50 ppm deuterium did not significantly affect the level of reactive oxygen species in neuron cultures, while MMP decreased by 16–20%. In experiments with glucose deprivation and temperature stress, the medium with 50 ppm increased the death of neurons. Thus, a short exposure of nerve cells in the medium with 50 ppm deuterium acts as an additional stressful factor, which is possibly associated with the violation of the cell energy balance. The decrease in the mitochondrial membrane potential, which is known to be associated with ATP synthesis, indicates that this effect may be associated with the cell energy imbalance. The decrease in the activity of the CA1 field hippocampal neurons may reflect reversible adaptive changes in the operation of fast-reacting ion channels.     

Investigations on reactions of cyclene α-oxides

The reaction of 1-vinyl-3-cyclohexene dioxide with sodioacetoacetic ester and hydrogen halides (HCl, HBr) is described. On the basis of IR absorption spectra, it has been established that the addition of acetoacetic ester takes place to the oxide ring of the vinyl group with the formation of 1-acety]-2(3)-(3′,4′-epoxycyclohexyl)butyrolactone. The addition of HCl depends on the reaction conditions: under mild conditions addition takes place predominantly at the epoxycyclohexane group (85%), and under more severe conditions a mixture of products of addition both to the oxide ring attached to the six-membered carbon ring and to the oxide ring of the ethylene grouping is formed in a ratio of 55∶45. The ratio of the isomers with epoxyethyl and epoxycyclohexane groups in the product of the addition of HBr is 60∶40.     

Investigations on reactions of cyclene <Emphasis Type="Italic">α</Emphasis>-oxides

The influence of the reaction conditions on the order of addition of alcohols and α-chloro ethers in an acid medium to dioxides of 1-vinyl-3-cyclohexene is described on the basis of a determination of the percentage content of the ratio of the isomers by IR spectroscopy. It has been established that under mild conditions the addition takes place selectively with the predominant opening of the oxide ring attached to the six-membered carbon ring. More severe conditions (higher temperature, smaller amount of solvent) favor the formation of isomers with an opened oxide ring on the ethylene grouping.     

Sorption Activity of Silver Nanoparticles

Russian Physics Journal - The absorption activity of silver nanoparticles (AgNPs) on the surface of fibers of natural and artificial origin is estimated. In addition, it is determined that the...     

Study of phase transformations in the Si67Fe33 thin-film system upon steady-state annealing

The elemental composition and features of structural and phase transformations in the Si-Fe-Si thin-film system (50–30–50 nm) upon steady-state annealing are studied as functions of the temperature and treatment time by energy-dispersive microanalysis and electron diffraction methods. Optimum annealing parameters for the formation of iron silicide FeSi and disilicide β-FeSi₂ are determined.