Comparative Effects of Deferiprone and Salinomycin on Lead-Induced Disturbance in the Homeostasis of Intrarenal Essential Elements in Mice

Lead (Pb) exposure induces severe nephrotoxic effects in humans and animals. Herein, we compare the effects of two chelating agents, salinomycin and deferiprone, on Pb-induced renal alterations in mice and in the homeostasis of essential elements. Adult male mice (Institute of Cancer Research (ICR)) were randomized into four groups: control (Ctrl)—untreated mice administered distilled water for 28 days; Pb-exposed group (Pb)—mice administered orally an average daily dose of 80 mg/kg body weight (BW) lead (II) nitrate (Pb(NO₃)₂) during the first two weeks of the experimental protocol followed by the administration of distilled water for another two weeks; salinomycin-treated (Pb + Sal) group—Pb-exposed mice, administered an average daily dose of 16 mg/kg BW salinomycin for two weeks; deferiprone-treated (Pb + Def) group—Pb-exposed mice, administered an average daily dose of 20 mg/kg BW deferiprone for 14 days. The exposure of mice to Pb induced significant accumulation of the toxic metal in the kidneys and elicited inflammation with leukocyte infiltrations near the glomerulus. Biochemical analysis of the sera revealed that Pb significantly altered the renal function markers. Pb-induced renal toxicity was accompanied by a significant decrease in the endogenous renal concentrations of phosphorous (P), calcium (Ca), copper (Cu) and selenium (Se). In contrast to deferiprone, salinomycin significantly improved renal morphology in Pb-treated mice and decreased the Pb content by 13.62% compared to the Pb-exposed group. There was also a mild decrease in the renal endogenous concentration of magnesium (Mg) and elevation of the renal concentration of iron (Fe) in the salinomycin-treated group compared to controls. Overall, the results demonstrated that salinomycin is a more effective chelating agent for the treatment of Pb-induced alterations in renal morphology compared to deferiprone.     

Formation of active sites in titanium-containing zeolites with MFI structure in propylene epoxidation with hydrogen peroxide

Propylene epoxidation with hydrogen peroxide on titanosilicates with different Si/Ti ratios and various states of titanium in the catalysts, prepared by hydrothermal crystallization according to two different procedures, has been investigated. It has been demonstrated that a change in the pH of the crystallizing gel leads to a change in the sequence of titanium insertion in the zeolite structure at a hydrothermal synthesis temperature of 170°C. It was shown that titanium incorporated in the zeolite framework in the tetrahedral positions is an active site in the epoxidation reaction, whereas titanium in the form of titanium dioxide leads to unproductive degradation of hydrogen peroxide.     

Thermoelectric properties of a Pb0.2Sn0.8Te solid solution prepared through thermal decomposition of salts

We have studied the thermoelectric properties of microcrystalline samples of the Pb_0.2Sn_0.8Te solid solution prepared by hot-pressing fine powders obtained through the thermal decomposition of lead acetate trihydrate and tin oxalate in the presence of tellurium powder. The electrical conductivity, Seebeck coefficient, and thermal conductivity of the samples have been measured at room temperature and in the temperature range 300–700 K and correlated with the particle size of the powders and heat-treatment conditions. We have compared the thermoelectric properties of hot-pressed samples from powders prepared through the thermal decomposition of salts and by mechanical grinding of ingots.     

Dramatic Effect of Vibrations on Dynamics of Rotating Hydrodynamic Systems

The results of theoretical and experimental investigation of the average dynamics of inhomogeneous systems in rotating cavity in the presence of oscillating force field are highlighted and analyzed. Average behavior of nonisothermal liquid as well as different multiphase systems (two liquids, liquid and gas, solid in liquid, granular matter in liquid) in quickly rotating horizontal cylinder subjected to vibrations of different direction is described. The specificity of dynamics of all the systems is determined by the Coriolis force which defines not only the average flows but the fluid oscillations also. The resonant excitation of inertial oscillations of liquid results in generation of intensive mean flows. The structure of vibrational streams is essentially determined by the type of inertial waves. So, excitation of an azimuthal wave generates azimuthal streams (outrunning or lagging, depending on frequency of the wave), three-dimensional standing waves (in the systems with deformable interface) generate regular spatial flows of high intensity. Under the resonant conditions the influence of vibrations appears to be very strong, the speed of mean streaming can achieve the values comparable with the speed of rotation of the container.     

Production of isobutylene from acetone over micro–mesoporous catalysts

The production of isobutylene from acetone over micro–mesoporous catalysts with different mesopore contents, which have been prepared using hydrothermal recrystallization of mordenite (MOR) zeolite modified with cesium acetate by incipient wetness impregnation, has been studied. It has been shown that cesium is inserted into the cation positions during the modification, at the same time the number of Brønsted acid sites in the samples decreased. It has been found that an increase in the content of mesopores in the catalyst leads to an increase in the initial rates of acetone conversion and isobutylene formation as a result of removing diffusion limitations. Brønsted acid sites have been shown to be preferable for the selective production of isobutylene from acetone. Micro–mesoporous materials operate more stably as compared to microporous materials.     

Modeling frequency-time synchronization systems that use signals of common sources

Article presents results of design and implementation of system model that uses signal of a common source to synchronize geographically distributed time and frequency standards (so-called general coverage algorithm). The use of various processing (mutual correlation and matched filtering) and estimation of time signal position methods as well as taking into consideration of multipath in channel are essential peculiarities of the model. The model may be used for estimating potential precision of a wide class of synchronization systems and the possibility of using various signals and processing techniques in such systems.     

New experimental evaluation techniques for selectivity of collecting agents for gold and platinum flotation from fine-impregnated noble metal ores

It is proposed to apply nanosize Au and Pt particles to ground mineral particles for the analysis of flotation and adsorptive properties of new reagents. The authors have obtained specimens of pyrite, arsenopyrite and quartz artificially enriched by nanosize gold particles. Reductive adsorption from Na₂[PtCl₆] and Na[AuCl₄] produced pyrrhotine uniformly applied with microsize platinum particles. The article discusses the application range of the proposed techniques and methods of examination of specimens and interaction between reagents and micro- and nanosize gold and platinum particles depending on the conditions of sulfide treatment by the noble metals and on properties of a host mineral. Advanced integrated analysis of interaction between the nitrogen-bearing reagent MTKh and gold confirmed chemically induced selectivity of MTKh towards gold