Influence of rutin-ammonium complex on the physiological condition of pine seedlings

In the plant body, phenolic compounds nonspecifically affect the processes of morphogenesis and perform a wide range of regulatory and protective functions. Of particular interest are the processes involved in the complexation of flavonoids as a result of their interaction with ammonium forms of nitrogen. Polar compounds, which are formed in tissues as a result of chemical transformation, are quite mobile in soil solutions and show high biological activity. The properties of phenol-ammonium complexes are of considerable interest in terms of morphogenesis, physiology of stability, as well as in the system of interaction of plants with soil microorganisms. Studies of the effect of phenol-ammonium complex were performed on seeds and seedlings of Scots pine. Quantitative indicators of germination energy and germination were determined by seed germination. Biochemical profiling of seedling tissue extracts was performed by high-performance thin layer chromatography. It has been experimentally confirmed that rutin (quercetin-3-O-rutinoside) after interaction with 10% aqueous ammonia solution forms a complex of substances, among which the chromatography revealed polar products that potentially affect the regulation of growth. At a total concentration of 15 mg/l, these substances significantly increased germination energy and seed germination. In pine seedlings, they stimulated the growth of roots and shoots. The effect of the complex of organic compounds on seedlings depended on the concentration, duration of seed treatment and had a prolonged effect. The obtained phenol-ammonium complex at a concentration of 10-15 mg/l contributed to an increase in the amount of chlorophylls, carotenoids in the tissues of seedlings, and at 20-40 mg/l increased the content of phenolic synthesis products.

Optimization of Magnetic Nanoparticles Draw Solution for High Water Flux in Forward Osmosis

In this study, bare iron oxide nanoparticles were synthesized using a co-precipitation method and used as a draw solute in forward osmosis. The synthesis conditions of the nanoparticles were optimized using the Box-Behnken method to increase the water flux of the forward osmosis process. The studied parameters were volume of ammonia solution, reaction temperature, and reaction time. The optimum reaction conditions were obtained at reaction temperature of 30 °C, reaction time of 2.73 h and 25.3 mL of ammonia solution. The water flux from the prediction model was found to be 2.06 LMH which is close to the experimental value of 1.98 LMH. The prediction model had high correlation factors (R2 = 98.82%) and (R2adj = 96.69%). This study is expected to be the base for future studies aiming at developing magnetic nanoparticles draw solution using co-precipitation method.

Comparison of Precursor Preparation Routes on Final Density of Y3Fe5O12 Garnets Prepared via Reactive Sintering

Yttrium iron garnet was obtained using four methods of synthesis. A modified citrate method and a modified citrate method with YIG (yttrium iron garnet, Y3Fe5O12) nucleation were used. In two subsequent methods, YIP (yttrium iron perovskite, YFeO3) and α-Fe2O3 obtained in the first case by the citrate method and in the second by precipitation of precursors with an ammonia solution were used as the input precursors for reaction sintering. Differential scanning calorimetry (DSC) measurements of the output powders obtained by all methods allowed to identify the effects observed during the temperature increase. Dilatometric measurements allowed to determine the changes in linear dimensions at individual stages of reaction sintering. In the case of materials obtained by the citrate method, two effects occur with the increasing temperature, the first of which corresponds to the reaction of the formation of yttrium iron perovskite (YIP), and the second is responsible for the reaction of the garnet (YIG) formation. However, in the case of heat treatment of the mixture of YIP and α-Fe2O3, we observe only the effect responsible for the solid state reaction leading to the formation of yttrium iron garnet. The obtained materials were reaction sintered at temperatures of 1300 and 1400 °C. Only in the case of material obtained from a mixture of perovskite and iron(III) oxide obtained by ammonia precipitation at temperature of 1400 °C were densities achieved higher than 98% of the theoretical density. The use of Hot Isostatic Pressing (HIP) in the case of this material allowed to eliminate the remaining porosity and to obtain full density.

Simultaneous estimation of ZY-19489 and its active metabolite ZY-20486 in human plasma using LC–MS/MS, a novel antimalarial compound

Aim: ZY-19489 is a new antimalarial drug candidate and selective LC–MS/MS method was established for estimation of ZY-19489 and its metabolite in human plasma. Materials & methods: LLE was employed for extraction, mass spectrometric quantification performed using positive ionization mode and DCP-IMP was used as an internal standard. The chromatographic separation was achieved using mobile phase 5 mM ammonium formate in water and 0.1% v/v ammonia solution in methanol: acetonitrile (90: 10%, v/v) and column Agilent Zorbex Extended C18, 3.5 μm, 100 × 4.6 mm with a 6-min run time. Results: The calibration curve of ZY-19489 was linear over range 1–500 ng/ml and 2–200 ng/ml for metabolite. Assay was reproducible, selective and devoid of matrix effect. Conclusion: The validated assay was implemented for clinical sample analysis derived from healthy human subjects and parasitemia-induced subjects.

Application of AgNPs/rGO Modified Nylon Fabric in Strain Sensing

The graphene oxide slurry was printed on the pre-stretched and non-pre-stretched nylon fabric by screen printing, and immersed in silver ammonia solution of different concentrations, and then reduced to obtain silver nanoparticles/reduced graphene oxide (AgNPs/rGO) modified nylon fabric with excellent conductivity. The surface morphology of the fabric was observed, and the performances of the fabric sensor that was scraped with graphene oxide slurry between the pre-stretched and non-pre-stretched states were explored. The resistance responses of the nylon fabric finished with different concentrations of silver ammonia solution under different strains (1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%) were investigated. The results showed that the nylon strain sensor was more sensitive and stable when the graphene oxide slurry was scraped in the pre-stretched state, and while the silver ammonia solution concentration was 10 mg/mL, the nylon fabric had maximum sensitivity and lowest hysteresis performance.

Revealing specific features of structure formation in composites based on nanopowders of synthesized zirconium dioxide

Peculiarities of formation of microstructure in composites based on chemically synthesized zirconium nanopowders obtained by the method of decomposition from fluoride salts were considered. Hydrofluoric acid, concentrated nitric acid, aqueous ammonia solution, metallic zirconium, and polyvinyl alcohol were used. It was established that the reduction of porosity in nanopowders in the sintering process is the main problem in the formation of high-density materials. Analysis of various initial nanopowders, their morphology, and features of sintering by the method of hot pressing with direct transmission of electric current was made. Peculiarities of obtaining the composites based on them with the addition of Al2O3 nanopowders applying the electric sintering method were considered. It was shown that the increase in the content of alumina nano additives leads to an increase in strength and crack resistance of the samples due to simultaneous inhibition of abnormal grain growth and formation of a finer structure with a high content of tetragonal phase. The influence of sintering modes on the formation of the microstructure of zirconium nanopowders has been studied for different contents of alumina additives. Electric current promotes the surface activity of nanopowders and its variable value promotes partial fragmentation of agglomerated grains thus affecting the composite structure. Physical-mechanical properties of the obtained samples, optimal compositions of mixtures, and possibilities of improving some parameters were determined. It was found that nanopowders of zirconium dioxide obtained by the method of decomposition from fluoride salts are quite suitable for the production of composite materials with high physical and mechanical properties. They can compete with imported analogs and enable obtaining of crack resistance of 7.8 MPa·m1/2 and strength of 820 MPa.

Prospects for selective-and-advanced recovery of rhenium from pregnant solutions of in-situ leaching of uranium ores at Dobrovolnoye deposit

Analysis of exploration materials and market conditions showed that by-product recovery of rhenium, one of the rarest strategic elements of the periodic system, was not always effective in processing the whole volume of pregnant uranium-bearing solutions. The main goal of the research was to develop an effective method for recovery rhenium from pregnant solutions in in-situ uranium leaching. The objectives of the research were as follows: evaluation of the possibility of selective-and-advanced recovery of rhenium from ores by in-situ leaching method and comparison of the technological advantages of the new proposed method with the known ones. The study involved the analysis of historical geological, mineralogical and geochemical information on the Dobrovolnoye deposit and analysis of technological aspects of by-product recovery of rhenium in the world practice. A selective-and-advanced scheme of rhenium recovery from pregnant uranium-bearing sulfate (sulfuric acid) solutions of the Dobrovolnoye deposit ISL (Russia) using mobile installations was proposed. The process has the following features: zoning of production blocks when constructing injection and extraction (pumping) wells; piping of selective extraction wells into a separate collecting pipe; implementation of advanced rhenium sorption. The process implementation makes it possible to obtain rhenium from economically viable areas of the uranium deposit. The mobile installation includes the following main units: a filter for purification (aftertreatment) to remove suspension, a chain of sorption apparatuses (sorption filters or columns), connecting fittings, control and measuring instruments. The sorption apparatuses are filled with rhenium-selective ionite (ion exchanger). As a selective sorbent for the primary concentration of rhenium from sulfate solutions (pH 2), weakly basic nitrogen-bearing ionites containing amine functional groups of various types can be used. If further concentration of rhenium is required, in order to unify the equipment used, materials with a mobile extractant phase (so-called TVEXs (solid extractants or Levextrel resins in English literature) and so-called “impregnated” or “impregnates”), such as TVEX-DIDA containing diisododecyl amine, or TAA-impregnate containing trialkylamine, can be used. Rhenium desorption from these materials is carried out by an ammonia solution, which allows producing rough ammonium perrhenate from the eluate. Economic aspects of the rhenium selective-andadvanced technology were evaluated. Implementation of the recovery selective-and-advanced technology allows obtaining rhenium from economically-viable areas of the uranium deposit.

THE DEVELOPMENT OF METHODS FOR DETERMINATION THE TOTAL OF ANTHRACENE DERIVATIVES IN RAW MATERIALS AND PREPARATIONS OF ALOE ARBORESCENS MILL.

Aloe arborescens Mill., family Asphodelaceae, is a pharmacopoeial plant, the raw material of which is used for the production of medicinal products for various therapeutic uses. The standardization of Aloe species in accordance with the requirements of the British, Japanese, European Pharmacopoeias and the United States Pharmacopoeia is carried out according to the barbaloin content by the spectrophotometric method. The methods are multistage, provide for preliminary acid hydrolysis in combination with the oxidation, liquid-liquid extraction of the formed aglycones and subsequent complexation with magnesium acetate. A mixture of isomers of aloin A and aloin B (barbaloin) and aloenin were isolated by chromatographic methods. It was determined that in all electronic spectra of the extracts and preparations from the leaves of Aloe arborescens Mill., a bathochromic shift of the long-wavelength band in the alkaline-ammonia solution is observed, which confirms the presence of anthracene derivatives. Under conditions of differential absorption, a maximum absorption is observed in the range of 412–416 nm, which indicates the advisability of using barbaloin in the analysis method, which has a maximum absorption at a wavelength of 412 nm. As a result of the study, there were developed methods for the quantitative determination of the total of anthracene derivatives in leaves and preparations of Aloe arborescens Mill. by using of the differential spectrophotometry calculated on barbaloin at an analytical wavelength of 412 nm. The content of total anthracene derivatives calculated on barbaloin was 0.60±0.03% in Aloe arborescens fresh leaves, 0.5±0.02% in freshly prepared juice, 0.135±0.006% in "Aloe juice" and 0.020±0.001% in "Aloe liquid extract", solution for subcutaneous administration, produced by ZAO "Vifitech" and OAO "Dalkhimpharm".