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In recent years, magnesium calcium phosphate materials have been considered as an alternative to calcium phosphate-based materials in reconstructive surgery. In this work, bone cements in the calcium phosphates–magnesium phosphates system were synthesized and studied. The interaction of this system with a cement liquid gives struvite MgNH4PO4·6H2O as the main phase. The obtained materials have a compressive strength of up to 54 ± 5 MPa, a setting time of 6–7 min, and a neutral pH value. The effect of the introduction of vancomycin to the cement materials was studied. Investigation of the kinetics of vancomycin release showed that up to 98% of the antibiotic is released within 21 days. The materials exhibited pronounced antibacterial activity against the Staphylococcus aureus and Escherichia coli strains. After the introduction of vancomycin, the zone of inhibition of bacterial growth more than doubled compared to the reference samples. In vivo tests were conducted, the structural factors were calculated based on the results of micro-CT. According to macro and micro signs, the cement materials are fully biocompatible; by the sixth week, the formation of new bone tissue is observed.

The influence of the coupling effect on the parameters of field Hall elements based on thin-film MOS transistors has been studied. Analysis of the development of today’s microelectronics shows the necessity of developing the element base for high performance sensors based on silicon technologies. One way to significantly improve the performance of sensing elements including magnetic field sensors is the use of thin-film transistors on the basis of silicon on insulator (SOI) structures. It has been shown that field Hall sensors (FHS) may become the basis of high-performance magnetic field sensors employing the coupling effect occurring in the double gate vertical topology of these sensing elements. Electrophysical studies of FHS have been conducted for different gate bias and power supply modes. The results show that the coupling effect between the gates occurs in FHS if the thickness of the working layer between the gates is 200 nm. This effect leads to an increase in the effective carrier mobility and hence an increase in the magnetic sensitivity of the material. Thus field Hall elements based on thin-film transistors fabricated using silicon technologies provide for a substantial increase in the magnetic sensitivity of the elements and allow their application in highly reliable magnetic field sensors.

Mechanical eye injury and damage to the blood-ocular barrier cause inflammation resulting in oxidative stress, which, in turn, triggers myocardial ischemia, since the heart's need for oxygen exceeds its supply. A rapid decrease in the oxygen concentration in ischemic tissues causes a switch from oxidative to anaerobic metabolism, when energy deficit initiates a chain of physiological processes. The discovery of the molecular mechanisms underlying the manifestation of oxidative stress in the cardiac tissues will enable the development of effective therapeutic approaches to such condition. Objective: to analyze the dynamics of glutathione peroxidase (GP) activity in cardiac tissues of rats in response to oxidative stress caused by mechanical eye injury. Materials and methods . In our experiment, we used 150 healthy white mature (8-month old) male rats weighing 190–210 g and kept under standard conditions in a vivarium. GP activity was evaluated before the experiment and then on days 1, 3, 5, 7, and 14. Nonparametric statistical analysis was used in this study. Conclusion . GP activity in cardiac tissues of rats during oxidative stress caused by mechanical eye injury was most effectively stabilized by standard treatment for mechanical eye injury plus injections of quercetin.

The hematoophthalmic barrier is one of the mechanisms of resistance that serves to protect the body and prevents homeostasis disorder when the body is affected by factors that can disturb this balance. One of the complications of mechanical trauma of the eye and violation of the hematoophthalmic barrier is the appearance of oxidative stress on the background of the general inflammatory process in violation of cellular structures. Objective: to study the dynamics of catalase activity in the heart and muscle tissue of rats under oxidative stress caused by mechanical action on the hematoophthalmic barrier. Materials and methods. The study was carried out on white neonatal mature healthy male rats of six months of age, weighing 200–220 g and having 150 pieces. The activity of catalase in heart and muscle tissue was studied before the beginning of the experiment, as well as on the 1st, 3rd, 5th, 7th and 14th day of the experiment using the standard Korolyuk M.A. method. The dynamics of catalase activity was evaluated by different methods of treatment of mechanical eye trauma, including the use of quercetin antioxidant. The results of the study. It was found that in addition to the standard therapy of mechanical eye injury injection of quercetin, the activity of catalase in the heart and muscular tissue after falling on the background of induced oxidative stress increases to the values of physiological norm by 14 days, which indicates the effective elimination of oxidative stress. Conclusions. The activity of catalase in rat heart and muscle tissue under oxidative stress caused by mechanical influence on hematoophthalmic barrier is most effectively stabilized under standard therapy of mechanical eye injury with addition of quercetin in the form of injections.

—Mechanochemical synthesis in a ball mill was applied for the nanocomposite Cu(CuO)–CeO2 catalyst preparation from CeO2 and following dopants: Cu metal and copper oxides of different morphology and composition (CuO pure and CuO containing 4 or 16.5 wt % of Cu2O). The materials obtained were examined with the use of X-ray phase analysis, scanning electron microscopy, temperature-programmed reduction in CO, H2, C2H6 (TPR-СО, TPR-Н2, and TPR-С2Н6), and tested as catalysts in reactions of selective CO oxidation in H2 excess (CO-PROX) and total C2H6 oxidation. New forms of oxygen with high low-temperature reactivity towards CO, H2, and C2H6 were found by TPR in the samples synthesized. It was shown that CO conversion was slightly affected by the dopant nature in the dopant-CeO2 mixture. Contrary, C2H6 conversion at low temperatures depends on dopant composition. The highest C2H6 conversion at 400°С (91.4%) was observed on Cu–CeO2. The lowest one (54.2%) was observed on CuO–CeO2. As was demonstrated, mechanochemical synthesis is a universal technique to produce copper oxide–ceria catalysts.

Ln2O3 + HfO2 (Ln = Nd, Dy) powders and ceramics have been studied in an oxidizing (O2) and a mild reducing (He) atmosphere using differential scanning calorimetry (DSC), thermogravimetry, mass spectrometric analysis of released gases, X-ray diffraction, IR spectroscopy, and Raman spectroscopy. The results demonstrate that both a mechanically activated oxide mixture of appropriate composition and the powders and ceramics prepared by heat-treating the mixture contain carbon-containing compounds (basic rare-earth carbonates and hydroxycarbonates) and/or at least 0.2–0.5 wt % carbon (X-ray amorphous or crystalline). As a result, during heating in an oxidizing atmosphere all of the samples release CO2 in the same temperature ranges (250–600 and 750–1200°C), which is accompanied by exothermic peaks in their DSC curves. The CO2 release in the range 250–600°C is due to the onset of decomposition of the basic rare-earth carbonates and hydroxycarbonates, which are present in small amounts in the starting mixture, powders, and ceramics. The CO2 release in the range 750–1200°C is due to the burnout of strongly bonded carbon and thermally stable carbon-containing compounds (rare-earth dioxymonocarbonates, Ln2O2CO3). The exothermic peaks in the DSC curve are due to fluorite LnHfO4 – δ (Ln = Nd, Dy) crystallization processes. We believe that synthesis in air, involving the formation of X-ray amorphous (fine-particle and nanocrystalline) precursors containing rare-earth oxides, which tend to form basic rare-earth carbonates and hydroxycarbonates in air, will always yield high-temperature ceramics containing carbon compounds and at least 0.5 wt % X-ray amorphous carbon and/or graphite. The amount of carbon and carbon-containing compounds in the dysprosium-containing ceramics is markedly smaller (~0.2%) than that in the neodymium-containing ceramics. The crystallization of the rare-earth hafnates is a rather slow process that can begin at temperatures as low as 550°C. The formation of Nd2Hf2O7 with the pyrochlore structure involves fluorite NdHfO4 – δ formation as an intermediate step, and a single-phase product can only be obtained by high-temperature firing at ~1600°C. Phase-pure DyHfO4 – δ with the fluorite structure can be obtained by firing at 1200°C.

The rate of DNA repair in human blood lymphocytes exposed to γ-radiation was shown to depend on the nuclear magnetic moment of magnesium ions. The decrease of DNA double-strand breaks occurs as a first-order reaction with the rate constants 1.1 × 10–3 s–1 and 1.6 × 10–3 s–1 for 25Mg2+ and 24Mg2+ ions respectively. Their ratio certifies magnetic isotope effect on the DNA repair; the latter occurs by 1.5 times slower with nuclear-magnetic 25Mg2+ ions than with nuclear nonmagnetic 24Mg2+ ions. The discovery of this effect is an irrefutable indicator that the DNA repair is spin-dependent and magneto-sensitive process, and its chemistry includes electron transfer and generation of radicals and radical pairs.

It is known that lipids are the building material of cell membranes, play an important role in the vital functions of cells, and this is a peculiar form of deposition of metabolic fuel reserves. In the last decade, thanks to numerous studies, it has been established that lipids are an integral part of the general metabolism and are actively involved in the processes of adaptation and regulation of many functions in the body. Disorders of lipid metabolism are the trigger in the pathogenesis of numerous diseases. The basis of many metabolic processes in the body is redox reactions. Uncompensated formation of reactive oxygen species or oxidative stress leads to a violation of the physiological activity of cell membranes, which leads to a violation of the integrity of the cell and triggers a cascade of degenerative processes, resulting in exponentially accelerated aging. The state of lipid peroxidation is estimated by the content of intermediate products - diene conjugates (DCs), since they reflect the early stages of oxidation. The aim of our study was to study the relationship between the distribution of concentration of diene conjugates in the blood serum and tissues of white outbred rats. To achieve this goal, the following tasks had to be solved: to determine the concentration of diene conjugates in the blood serum and tissues of the liver, brain, heart, as well as in the skeletal muscle tissues of rats; to reveal the relationship between the distribution of DC concentration in blood serum and rat tissues. The article presents the results of a nonparametric correlation analysis to assess the relationship between the distribution of concentration of diene conjugates in blood serum and tissues of outbred rats.

Cationic polymerization of caprolactam was used to produce polyamide-6 modified with electrochemically oxidized graphite. Thermal expansion of oxidized graphite under the conditions for synthesizing the polyamide matrix was confirmed. The experimental functional properties of the developed material improved.

The purpose of our work was to assess the capabilities of the SEM in the framework of expert studies of gunshot injuries of targets made of cotton fabric. In the study of experimental injuries resulting from shots fired from the KO-M1-98 carbine with 8x57JS cartridges at various distances (from the stop to 3.5 m), the presence of features of the soot morphology was established, by which it is possible to judge the distance of the shot. Thus, by examining fragments of target tissue from the central and peripheral zones of soot deposition, electron microscopy revealed a change in the ratio, intensity, and topography of soot particles. The energy-dispersion analysis revealed that with increasing distance, the number of chemical elements that make up the capsule decreases, with the exception of tin, which has an unstable inversely proportional bond.Оценка возможностей сканирующей электронной микроскопии при проведении экспертных исследований огнестрельных повреждений мишеней из хлопчатобумажной ткани. При исследовании экспериментальных повреждений, полученных в результате выстрелов из карабина КО-М1-98 патронами 8х57JS на различных расстояниях (от упора до 3,5 м), установлено наличие особенностей морфологии копоти, по которым можно судить о дистанции выстрела. Так, исследуя фрагменты ткани мишени из центральной и периферической зон отложения копоти с помощью электронной микроскопии, установили изменение соотношения, интенсивности и топографии частиц копоти. При энергодисперсионном анализе установлено, что с увеличением расстояния количество химических элементов, входящих в состав капсюля, уменьшается, за исключением олова, которое имеет неустойчивую обратно пропорциональную связь.

The dehydrogenation of bicyclohexyl over single-component Ni-containing catalyst supported on oxidized Sibunit containing 3, 10, and 20 wt % of Ni is studied. The effect of addition of small amounts of Pt to Ni-catalysts on their activity with respect to hydrogen release is investigated. It is shown that the presence of nickel in the oxidized state facilitates electron transfer from platinum, reducing the dehydrogenation properties of two-component (Ni–Pt)-catalysts. It is established that the formation of a shell from the two metals on the surface of the material greatly slows the process of carbon support methanation.

GaOx/SiO2 catalytic systems with a gallium content of 3–50 wt% and deposited on SiO2 with different texture characteristics were synthesized by incipient wetness impregnation. The effect of the support nature on the catalyst activity in the reaction of propane dehydrogenation in the presence of CO2 was studied. The physicochemical properties of the supports and catalysts were characterized using low-temperature nitrogen adsorption, XRD, TPR-H2, UV–Vis and diffuse reflectance FTIR spectroscopy, SEM, X-ray microanalysis, TEM, TG-DTA. It was found that a high dispersion of Ga2O3 particles on the support surface and a low acidity of the catalyst are required to achieve a high catalytic activity of Ga-containing catalytic systems. The best results were found for the catalyst supported on SiO2 with a surface area of 747 m2/g and a gallium content of 7 wt%, the propane conversion reached 33% with a propylene selectivity of 84%, and the stable operation time of the catalyst was more than 20 h.

Small sugars are known to stabilize biological membranes under extreme conditions of freezing and desiccation. The proposed mechanisms of stabilization suggest membrane-sugar interactions to be either attractive or repulsive. To obtain new insight into the problem, we use a recently developed low-frequency Raman scattering approach which allows detecting membrane mechanical vibrations. For model membranes of palmitoyl-oleoyl-glycero-phosphocholine (POPC) hydrated in aqueous sucrose and trehalose solutions, we studied the Raman peak between 12 and 15 cm

Fucoxanthin, as a main marine carotenoid, exhibit a wide variety of bioactivities, including antioxidant activity. Previously, we have shown the geroprotective activity of fucoxanthin on Drosophila and C. elegans. Our new study aimed to compare the antioxidant activity of fucoxanthin in early and late passage normal human cells LECh4(81) in physiological conditions and under oxidative stress. In addition, using the RNA-seq we have analyzed the transcriptomic changes during the replicative senescence of fibroblasts treated with fucoxanthin. Results showed that fucoxanthin at a concentration of 5 μM caused the most pronounced antioxidant effect in the late passage cells. Moreover, transcriptomic data showed the increased expression levels of genes related to the Nrf2/ARE pathway. According to the analysis of enriched KEGG pathways, fucoxanthin altered cellular processes like ribosome biogenesis, lipid metabolism, and cell cycle regulation including some age-related pathways such as Wnt, JAK-STAT, and FoxO signaling pathways. We suggest that fucoxanthin may have therapeutic potential for treating age-related diseases.

We studied the effect of non-selective agonist of VIP receptors of vasoactive intestinal polypeptide in different concentrations on the frequency, force, and duration of isometric contraction of myocardial strips of the right atrium under conditions of spontaneous activity, as well as the force and duration of contractions of the right ventricle in rats. It was found that the agonist produced a positive inotropic and chronotropic effect that depended on its concentration. The maximum effect was observed at vasoactive intestinal peptide concentration of 10-11 M.

The influence of lithium substitution for calcium over a broad concentration range (0–20 mol %) on the crystal lattice parameters, coherent scattering regions, and phase composition was studied for hydroxyapatite synthesized by precipitation from solutions and heat treatment at 900, 1200, and 1400°C. The lithium substitution in a more than 10 mol % concentration and increase in the heat treatment temperature to 1400°C give rise to a complex phase composition, which includes not only the apatite phase, but also two tricalcium phosphate phases and calcium pyrophosphate. The results are useful for the development of hydroxyapatite-based materials for bone surgery.

The effect of the content of temporary process binder (paraffin, oleic acid, and beeswax) in the range of 10–18% on the molding of the silicon carbide products using hot slip casting has been studied. It has been determined that the flawless compact blanks based on SiC with Y3Al5O12 can be prepared at the TPB content of 14%. The conditions of four-stage heat treatment of the specimens during removal of TPB have been determined. The bending strength of the ceramic specimens prepared by sintering of the blanks at 1800°C is 437 ± 0.2 MPa.

Candida albicans is one of the most common pathogens of opportunistic infections and has a lot of hydrolytic enzymes important for pathogenesis of candidiasis, such as protease, phospholipase, and others. The genome of C. albicans contains seven phospholipase genes C (pla, plb1 plb2, plc1, plc2, plc3, and pld1), only four of which are well studied and well described (plb1 plb2, plc, and pld1); the role of others in the pathogenesis of candidiasis remains unclear. In this paper, the effect of iron on the hemolytic activity (HA) and gene expression of phospholipase C—plc, plb1, and plb2 by C. albicans in a nutrient broth and serum is studied. It is established that the addition of iron in the broth and serum induces a hemolytic activity and gene expression plb1 and plb2 of phospholipase C by C. albicans. In the serum, the highest dependence on the iron concentration ([Fe2+]) was observed for the expression of the plb2 gene and plc phospholipase C. Comparative characteristics of the presented results showed that in the serum, the expression level of the phospholipase C genes is lower than in the Saburo broth. The highest iron dependence is observed for the plb2 gene. It can be demonstrated according to the research that the nature of the hemolytic activity of C. albicans is due to the expression of the phospholipase gene plb2; the value of other genes in the expression of HA substantially depends on the medium of cultivation. Thus, any changes of iron homeostasis in the direction of an overloaded iron induce the activity of phospholipase C PLB2 and PLС by Candida spp. making iron from hemoglobin available for uptake, which is important for the pathogenesis of candidiasis.

A structure-guided hybridization approach using two privileged substructures gave instant access to a new series of tankyrase inhibitors. The identified inhibitor 16 displays high target affinity on tankyrase 1 and 2 with biochemical and cellular IC50 values of 29 nM, 6.3 nM and 19 nM, respectively, and high selectivity toward other poly (ADP-ribose) polymerase enzymes. The identified inhibitor shows a favorable in vitro ADME profile as well as good oral bioavailability in mice, rats, and dogs. Critical for the approach was the utilization of an appropriate linker between 1,2,4-triazole and benzimidazolone moieties, whereby a cyclobutyl linker displayed superior affinity compared to a cyclohexane and phenyl linker.

Al-substituted beta-tricalcium phosphate (β-TCP) nanopowders containing 0–20 mol.% of Al were obtained via precipitation method. The effect of Al content on the phase composition, lattice parameters, crystallite size, specific surface area and morphology of powders was established. Over the substitution range 0 – 1 mol.% the synthesis products consist of single whitlokite-like phase. For 5 – 20 mol.% two separate whitlokite-like phases were indentified: Al enriched Ca 9 Al(PO 4 ) 7 and β-TCP solid solution. For both phases, the general trend is a reduction of cell parameters, as well as decrease of crystalline and particle size with an increase of Al content. Powder with 20 mol.% of Al consists of 84 wt% of Ca 9 Al(PO 4 ) 7 and 16 wt% of β-TCP solid solution and is formed by spherical particles with average size of 20–30 nm and specific surface area of 129 m 2 /g.

Mechanisms underlying the effects of low-dose ionizing radiation (IR) exposure (10-100 mGy) remain unknown. Here we present a comparative study of early (less than 24h) and delayed (up to 11 post-irradiation passages) radiation effects caused by low (80 mGy) vs intermediate (1000 mGy) dose X-ray exposure in cultured human bone marrow mesenchymal stem cells (MSCs). We show that γН2АХ foci induced by an intermediate dose returned back to the control value by 24 h post-irradiation. In contrast, low-dose irradiation resulted in residual γН2АХ foci still present at 24 h. Notably, these low dose induced residual γН2АХ foci were not co-localized with рАТМ foci and were observed predominantly in the proliferating Кi67 positive (Кi67+) cells. The number of γН2АХ foci and the fraction of nonproliferating (Кi67-) and senescent (SA-β-gal+) cells measured at passage 11 were increased in cultures exposed to an intermediate dose compared to unirradiated controls. These delayed effects were not seen in the progeny of cells that were irradiated with low-dose X-rays, although such exposure resulted in residual γН2АХ foci in directly irradiated cells. Taken together, our results support the hypothesis that the low-dose IR induced residual γH2AХ foci do not play a role in delayed irradiation consequences, associated with cellular senescence in cultured MSCs.

Literary data have been used to assess the inflow of petroleum hydrocarbons (with river runoff, precipitation, wastewaters, sea transport, and at ice thawing) into different regions of the White Sea. The hydroecological CNPSi-model was used as an instrument to reproduce the annual dynamics of hydrocarbon concentrations at their parallel inflow and subsequent transformation in the waters of the nine White Sea regions (the bays of Kandalaksha, Onega, Dvina, and Mezen; the Solovetskie Islands; the deep-water part: Bassein, Gorlo, Voronka, and Chupa Bay). The calculations were based on normal annual values of monthly variations of water temperature, light intensity, and transparency, the morphometric parameters of the regions (water areas, mean depths, and water volumes) and water exchange between the regions and with the Barents Sea (calculated by a hydrodynamic model). The calculated concentrations of hydrocarbons, the biomasses and activity characteristics of hydrocarbon-oxidizing bacteria have been analyzed (their values were estimated for the 2-m surface water layer). The results of calculations were used to evaluate hydrocarbon balances for regions and the sea as a whole. The calculations demonstrate the balanced character of hydrocarbon fluxes, the balance discrepancy for the regions being

DNA double-strand breaks (DSB) are among the most harmful DNA lesions induced by ionizing radiation (IR). Although the induction and repair of radiation-induced DSB is well studied for acute irradiation, responses to DSB produced by chronic IR exposures are poorly understood, especially in human stem cells. The aim of this study was to examine the formation of DSB markers (γH2AX and phosphorylated kinase ATM, pATM, foci) in human mesenchymal stem cells (MSCs) exposed to chronic gamma-radiation (0.1 mGy/min) in comparison with acute irradiation (30 mGy/min) at cumulative doses of 30, 100, 160, 240 and 300 mGy. A linear dose-dependent increase in the number of both γH2AX and pATM foci, as well as co-localized γH2AX/pATM foci (“true” DSB), were observed after an acute radiation exposure. In contrast, the response of MSCs to a chronic low dose-rate IR exposure deviated from linearity towards a threshold model, for γH2AX, pATM foci and γH2AX/pATM foci, with an indication of a “plateau”. The state of equilibrium between newly formed DSB at a low rate during the protracted exposure time and the elimination of a fraction of DSB is proposed as a mechanistic explanation of the non-linear DSB responses following a low dose-rate irradiation. This notion is supported by the observation of the elimination of a substantial fraction of DSB 6 h after the cessation of the exposures. Our results demonstrate non-linear dose responses for γH2AX and pATM foci in human MSCs exposed to low dose-rate IR and showed the existence of a threshold, which may have implications for radiation protection in humans.

Proteins can aggregate in response to stresses, including hyperosmotic shock. Formation and disassembly of aggregates is a relatively slow process. We describe a novel instant response of the cell to hyperosmosis, during which chaperones and other proteins form numerous foci with properties uncharacteristic of classical aggregates. These foci appeared/disappeared seconds after shock onset/removal, in close correlation with cell volume changes. Genome-wide and targeted testing revealed chaperones, metabolic enzymes, P-body components and amyloidogenic proteins in the foci. Most of these proteins can form large assemblies and for some, the assembled state was pre-requisite for participation in foci. A genome-wide screen failed to identify genes whose absence prevented foci participation by Hsp70. Shapes of and interconnections between foci revealed by super-resolution microscopy indicated that the foci were compressed between other entities. Based on our findings, we propose a new model of the cytosol architecture as a collection of numerous of gel-like regions suspended in a liquid network. This network is reduced in volume in response to hyperosmosis and forms small pockets between the gel-like regions.

Indibulin (D-24851) derivatives with bisphosphonate fragment connected to the N1 atom of imidazole ring were synthesized by alkylation of (indolyl-3)methylglyoxylates with ethylenebisphosphonate. Biological evaluation of targeted compounds 4a–d using the phenotypic sea urchin embryo assay provided evidence that replacing of p-chlorobenzene ring in indibulin by bisphosphonate group did not eliminate antimitotic microtubule destabilizing activity. The most active molecule, tetraacid 5a, at physiological pH formed tetrasodium salt 6a with aqueous solubility value of at least 10 mg/mL. Molecule 5a was more potent in the sea urchin embryo assay than the parent indibulin. This compound also exhibited pronounced cytotoxicity against A549 lung carcinoma and A375 melanoma cell lines.

The characteristics of thin-film Si MISIM magnetic transistors with a built-in accumulated channel and partially depleted quasi-neutral area are studied. The design of transistors is integrated with a Hall element. It is shown experimentally that transistors of this type, which were named field-effect Hall sensors (FEHSs) and made by the “silicon-on-insulator” (SOI) technology, provide measurements of the magnetic induction in a temperature range of 1.7–605 K. Theoretical estimates show that the upper operating temperature limit of the FEHS can be about 850 K.

This paper presents a detailed study of the formation of chromium-based alloys, Cr–Ta–W + plasticizing additives (Nb and Zr) and Cr–Ta–Si, during milling of powder mixtures in a Fritsch (P-7) planetary mill under an Ar atmosphere. It is shown that, after milling for 18 h, all the components of the starting mixtures convert into a Cr-based BCC solid solution. The powders of chromium alloys obtained in this study are readily compacted by hot isostatic pressing (HIP) under conditions typical of the processing of powders of high-temperature nickel alloys. Heating of the powders and compacts leads to the decomposition of the supersaturated solid solution and the formation of two forms of the Cr2M Laves phase with cubic crystal lattices. The formation of a mixed-phase fine microstructure in the chromium alloys after HIP suggests that the materials studied here are potentially attractive as a base of next-generation chromium-based high-temperature alloys.

X-ray diffraction and thermal analyses, microscopy, and specific surface area measurements are used to study the formation, structure, and reactivity of mechanoactivated Mg/MoO3 and Al/MoO3 nanocomposites during slow heating (10°C/min). The optimal mechanoactivation dose is determined. The mechanoactivated Mg/MoO3 composite is a dense mixture of two nanosized components with a contact surface of ~8 m2/g (upper estimate). The area of the contact surface between the components of the Al/MoO3 composite is less than 2 m2/g, with the sample consisting of micron-sized aluminum flakes coated with nanoparticles oxide nanoparticles. When heated, the Mg/MoO3 system explodes, with the temperature of explosion being determined by the heating conditions. The minimum temperature of conversion is ~250°C, close to the temperature of autoignition of fuel–air mixtures promoted by these additives. The Al/MoO3 system is characterized by a phased progress of the reaction in the temperature range of 200 to 1000°C. The reasons for the differences in the reactivity of the mixtures are discussed.

Using mechanochemical synthesis through milling of equiatomic multicomponent mixtures of Cr, Fe, Co, Ni, Al, Ti, Mo, and Nb metals in various combinations, we have synthesized powder alloys with different phase compositions: amorphous phase (AP), AP + BCC phase, AP + BCC phase + MO, and FCC + BCC phases. The FCC phase has been shown to be a Ni-based solid solution. The presence of aluminum in a starting mixture helps to stabilize the BCC phase owing to the formation of a disordered B2 phase. Al dissolves in both the BCC and FCC solid solutions, increasing their lattice parameters. In Al-free starting mixtures, Cr is responsible for the formation of the BCC solid solution. The formation of an AP during milling of multicomponent mixtures is favored by the presence of transition metals with a large atomic radius: Ti, Mo, and Nb.

We describe a magnetosensitive device consisting of a combination of a thin-film Si transistor with built-in conducting channel (fabricated by the silicon-on-insulator technology) and a Hall-type sensor (HS). The transistor has a double-gate field control system of the metal–insulator–semiconductor–insulator–metal type and operates in the regime of carrier accumulation in the channel at partial depletion of adjacent regions of the Si film. It is established that the device can operate at temperatures up to about 350°C, which is 160–180°C higher than the maximum operating temperature of HSs based on bulk Si crystals and comparable with HSs based on wide-bandgap semiconductors.

Raman spectra in the low-frequency spectral range---between 5 and $90\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}$---were studied for multilamellar bilayers prepared with cholesterol (Chol) and phospholipids of three different types: doubly unsaturated lipids 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), monounsaturated lipids 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and fully saturated lipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). The narrow peak seen below 250 K and positioned between 9 and $18\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}$---depending on the system and temperature---was attributed to the vibrational eigenmode of a lipid monolayer. For the DOPC-Chol bilayer, the peak position and the peak width were found to monotonically increase and decrease, respectively, with the Chol concentration. For POPC-Chol and DMPC-Chol bilayers, these parameters revealed nonmonotonic concentration dependences, with an apparent minimum at the intermediate Chol content. The peak intensity was ascribed to interleaflet coupling. As in the literature, a coexistence of liquid-ordered and solid-ordered domains was suggested for the DMPC-Chol and POPC-Chol bilayers; the Chol concentration dependences of Raman peak parameters were discussed in line with this suggestion, under the assumption that the different composition of coexisting domains conserves upon cooling. We demonstrated that the obtained Raman data disagree with the suggested domain coexistence if the domain sizes are substantially larger than the lipid layer thickness.

A technology for obtaining materials from nanostructured nitinol with titanium- or tantalum-enriched surface layers was developed. Surface layers enriched with titanium or tantalum were shown to provide a decrease in the formation of reactive oxygen species and long-lived protein radicals in comparison to untreated nitinol. It was determined that human peripheral vessel myofibroblasts and human bone marrow mesenchymal stromal cells grown on nitinol bases coated with titanium or tantalum-enriched surface layers exhibit a nearly two times higher mitotic index. Response to implantation of pure nitinol, as well as nano-structure nitinol with titanium or tantalum-enriched surface layers, was expressed though formation of a mature uniform fibrous capsule peripherally to the fragment. The thickness of this capsule in the group of animals subjected to implantation of pure nitinol was 1.5 and 3.0-fold greater than that of the capsule in the groups implanted with nitinol fragments with titanium- or tantalum-enriched layers. No signs of calcinosis in the tissues surrounding implants with coatings were observed. The nature and structure of the formed capsules testify bioinertia of the implanted samples. It was shown that the morphology and composition of the surface of metal samples does not alter following biological tests. The obtained results indicate that nano-structure nitinol with titanium or tantalum enriched surface layers is a biocompatible material potentially suitable for medical applications.

Chemical genomics attracts considerable attention by offering crucial tools for plant biology to regulate plant growth and development. However, most chemical screens are time consuming and laborious, and require a high input of resources. Here we describe a broadly applicable method for the ultrarapid high-content phenotypic screening of small chemical compound libraries for new plant growth regulators. The assay is based on determination of pollen tube growth and can be completed in less than 8 h. Using this method, we identified novel inhibitors and modulators of plant growth and showed that compounds selected using a Nicotiana tabacum-based assay were biologically active in other plants, such as Arabidopsis thaliana.

The isothermal section of the equilibrium phase diagram of the Co–Ni–Cr system at 1375 K is constructed using the equilibrium alloy method. The existence of the sCr + γ + σ three-phase equilibrium in the Co–Ni–Cr system at 1375 K is found.

Ternary and quaternary alloys of the Nb-Al-Si and Nb-Al-Si-C systems have been produced by mechanochemical synthesis. Our results demonstrate that the milling of a 62Nb + 19Al + 19Si ternary mixture, whose composition corresponds to that of the intermetallic phase Nb10Al3Si3, leads to the formation of an amorphous phase, whereas the milling of a 86Nb + 9Al + 5Si mixture, corresponding to a solid solution, results in the formation of a two-phase mixture, consisting of an amorphous phase and a nanostructured (7 nm) bcc solid solution. The addition of graphite to the starting mixtures homogenizes the MS products and reduces their particle size to ≃2 nm. The milling of a mixture with the composition Nb10Al3Si3C10 causes no changes in phase composition. The milling of a 78Nb + 8Al + 5Si + 9C mixture leads to the formation of an additional phase: nanoparticulate niobium carbide. Using differential thermal analysis, we have identified the sequence of transformations underlying the transition of the MS alloys to an equilibrium state. After the compaction of the MS powders by hot isostatic pressing, the samples prepared from the graphite-containing mixtures were more homogeneous in the case of both the alloys based on the intermetallic phase and the Nb-based solid solutions. The carbide nanoparticles precipitating on grain boundaries increase the hardness HV of the alloys by almost 30%: from 12.75 to 18.13 GPa for the samples corresponding to the intermetallic phase and from 4.76 to 6.85 GPa for the samples corresponding to solid solutions.

Defect structure of mechanically activated MoO3 has been studied with the use of X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance, laser granulometry, and adsorption methods. Two stages of mechanical activation have been distinguished. At mechanical activation doses below 1 kJ/g, the fracture of oxide particles is the main process. At this stage, MoO3 particle sizes decrease from 30 μm to 60 nm and specific surface area linearly increases to 30 m2/g, the sizes of coherent-scattering regions decrease to 18 nm, paramagnetic centers are accumulated, and the Raman spectral bands corresponding to three different types of Mo-O bonds widen and shift. At doses above 1 kJ/g, the main process consists in the friction and aggregation of particles, which is accompanied by some reduction in the specific surface area and an increase in the particle sizes. At the stage of friction, the phase transition from an orthorhombic modification to a monoclinic modification of MoO3 occurs seemingly due to a shift of one layer of the material in plane (100). The shift is accompanied by the accumulation of lattice microstrains in the same plane, formation of “stressed” Mo-O-Mo bridge bonds, and a substantial rise in the concentration of Mo5+ radicals. The maximum total concentration of paramagnetic centers is 1 × 1018 g−1. It may be assumed that the radicals are formed due to the rupture of the most stressed molybdenum-oxygen bridge bonds.

Mechanical activation has been employed to produce highly reactive energy-saturated Mg/(-C2F4-)n composites, chemical transformations in which are initiated by either heating or shock-wave loading. The structure and reactivity of these composites have been analyzed with the use of X-ray diffraction, microscopy, thermogravimetry, calorimetry, and the measurement of combustion and detonation velocities. Mechanical activation is accompanied by the formation of a magnesium/fluoroplastic composite structure with the intercomponent contact area as large as 6 m2/g and accumulation of chaotically arranged dislocations to concentrations as high as 6 × 1010 cm−2, basal and prismatic deformation stacking faults (the maximum probabilities of their formation are 2.1 and 1.4%, respectively), and boundaries of coherent-scattering regions in magnesium. In fluoroplastic, disordering and partial amorphization of the structure take place. Mechanical activation leads to a dramatic increase in the propagation velocity of Mg + (-C2F4-)n → MgF2 + C chemical reaction in the explosive combustion regime (to 400 m/s) and the development of knocking combustion, in which the reaction propagates at a velocity as high as 1100 m/s. The optimal dose of mechanical activation (7–8 kJ/g), at which the maximum velocity of reaction propagation is reached, has been determined. The use of a “slow” heating in the cell of a calorimeter in combination with the mass-spectral analysis of evolved gases has made it possible to distinguish processes of three types in the thermally activated interaction between magnesium and fluoroplastic. The formation of MgF2 at temperatures below 300°C seems to be due to the interaction between defects in magnesium (dislocations and stacking faults) and macromolecules. The reaction occurring at 300–420°C with a slight thermal effect is caused by the solid-phase interaction between magnesium and fluoroplastic brought in contact with one another. The main contribution to the conversion is made by the processes that take place at temperatures above 420°C and are relevant to the thermal depolymerization of fluoroplastic. The layered structure of the composite and the large area of the intercomponent contact ensure the penetration of gaseous products of depolymerization into the bulk of magnesium particles and the completeness of the interaction.

Antibacterial compounds are one of the essential classes of clinically important drugs. High throughput screening allowed revealing potential antibiotics active towards any molecular target in bacterial cell. We used a library of 9820 organic compounds with highly diversified structures to screen for antibacterial activity. As the result of automated screening, 103 compounds were found to possess antibacterial activity against Escherichia coli. The properties of these compounds were compared with those of initial library. Non-linear Kohonen mapping was used to analyze the differences between non-active molecules from initial library, identified antibacterial hits and compounds with reported antibacterial activity. It was found that identified antibacterial compounds are located in the separated area of chemical space. It can be therefore suggested that these molecules belong to novel classes of antibacterial compounds and could be studied further.

The genesis of a defective structure (particle size, size of coherent scattering regions (CSRs), dislocation concentrations, and two types of deformation and twin stacking defects (SDs)) of magnesium during its mechanical activation in a vibrating mill in the presence of liquid additions was studied by X-ray diffraction (XRD) analysis, microscopy, and adsorption (BET) method. The dynamic mechanical properties were checked for the activated samples using a K-44-2 vertical impact machine. The ability of magnesium to be oxidized in air was checked by heating it in the cell of a differential scanning calorimeter. At mechanical activation doses of less than 5 kJ/g, the accumulation of chaotically arranged dislocations and deformation SDs was accompanied by an increase in the plasticity of the material. At higher doses, polygonization of dislocations led to a drastic decrease in the CSR size and dislocation run, leading to embrittlement of the material. The changes in the mechanical properties were confirmed by symbatic changes in the outer particle size and showed themselves on the pressure oscillograms during the impulse loading of pressed Mg layers. Mechanical activation led to an increase in the level of oxidation of magnesium with oxygen, but did not affect the temperature of the start of oxidation. A method for activating magnesium with additions was suggested and led to the formation of highly disperse magnesium samples with the oxidation temperature lowered by 150°C.

Mechanochemical activation was used in the synthesis of CuO-CeO2 catalysts for the preferential oxidation of CO in the presence of excess H2. Catalysts similar in properties to supported CuO/CeO2 systems were prepared from mixtures of copper oxide (5 or 10 wt % CuO) and cerium dioxide with the use of mechanochemical activation. It was found that the time of mechanochemical activation influences the catalytic properties: a maximum conversion of CO into CO2 (97%) at 140°C was achieved with a sample of 10 wt % CuO-90 wt % CeO2 after mechanochemical activation in a ball mill for 90 min. Changes in the phase compositions of the catalysts depending on mechanochemical activation time and reaction mixture composition were studied by X-ray diffraction. The interaction of the oxides of copper and cerium in the process of mechanochemical activation with the formation of new Cu-O-Ce surface structures, which, supposedly constitute active sites for CO oxidation, was found using differential scanning calorimetry and differential thermogravimetric analysis.

The search for new antibiotics is an important task, which is of interest for both basic research and health care practices. It is essential to elucidate the mechanism of antimicrobial action during the screening for antimicrobial activity and at the same time be able to test thousands of compounds. A robotic screening system for potential antibiotics developed at the Department of Chemistry at Moscow State University has been described that enables the immediate identification of those that inhibit protein biosynthesis.

Solid solutions Ni(Al, Mo, C) are formed via milling the Ni2.8Al1Mo0.2 and Ni3Al0.8Mo0.2 and graphite-containing Ni2.8Al1Mo0.2C(0.25, 0.5) and Ni3Al0.8Mo0.2C(0.25, 0.5) mixtures. In this case, some amount of Mo remains beyond the solid solution. Graphite added to a starting mixture decreases the Mo solubility and favors the amorphization of solid solutions. The complete amorphization was found for the mixture with the 5 at % C and 5 at % Mo, which was added instead of Ni. The heating of mechanically synthesized (MS) powder alloys leads to the ordering of carbon-free and carbon-containing solid solutions with the formation of the L12 and E21 structure, respectively. In the course of the ordering of the Ni(Al, Mo, C) solid solutions, Mo and carbon precipitate in the form of the molybdenum carbide (Mo2C) second phase. The hardness of the MS three-phase Ni-Al-Mo-C solid solutions subjected to hot isostatic pressing is determined by the mass fraction of the formed Mo2C carbide. It is shown that the carbon content in the multicomponent antiperovskite can be estimated by analyzing the ratio of integral intensities of superlattice reflections I(100)/I(110).

Mechanochemical synthesis (MS) of Ni70Al25Mo5 (composition 1) and Ni75Al20Mo5 (composition 2) mixtures, in which 5 at % Mo substitutes for the equal amount of Ni or Al, leads to the formation of Ni-based nanocrystalline (coherent domains are ∼7–12 nm in size) solid solutions; in this case, some amount of molybdenum remains free. A comparison of the lattice parameters of solid solutions, which were determined experimentally, with the magnitudes determined theoretically using Vegard law and Bozollo-Ferrante simulation, which takes into account volume modules of elasticity of elements, showed an increase in interactions between atoms composed the solid solution and the formation of regions characterized by short-range order. The heating of mechanically synthesized three-component Ni(Al, Mo) solid solutions to 720°C in a calorimeter chamber forms the ordered γ′ phase (L12) at T ∼ 450°C. An analysis of the ratio of relative intensities of superlattice and fundamental reflections showed that, whatever the composition of initial mixture, Mo atoms always occupy positions in the Al sublattice. This arrangement of Mo atoms was confirmed by calculations of coefficients of concentrational variations of the lattice parameters. When molybdenum is added to Ni3 Al, Mo atoms, rather than Ni atoms, complete the Al sublattice. In this case, vacancies compensate for the lack of atoms in the Ni sublattice.

Catalytic systems designated for preferential oxidation of CO in the presence of H2 are prepared by ball milling of Cu and CeO2, a simple and cheap one-step process to synthesize such catalysts. It is found that after 60 min of milling, a mixture of 8 wt.% Cu–CeO2 powders exhibits CO conversion of 96% and CO selectivity of about 65% at 438 K. Two active oxygen states, which are not observed in case of pure CeO2, were detected in the nanocomposite lattice and attributed to the presence of Cu in surface sites as well as in subsurface bulk sites. Correspondingly, oxidation of CO to CO2 was found to occur in a two-stage process with Tmax ≈ 395/460 K, and oxidation of H2 to H2O likewise in a two-stage process with Tmax ≈ 465/490 K. The milled powder consists of CeO2 crystallites sized 8–10 nm agglomerated to somewhat larger aggregates, with Cu dispersed on the surface of the CeO2 crystallites, and to a lesser extent present as Cu2O. [Figure not available: see fulltext.] © 2016, Springer Science+Business Media Dordrecht.

By examining cell adhesion to n-hexadecane, the hydrophobicity index of S. aureus, E. coli, and P. aeruginosa was measured. It has been established that an increase in the hydrophobicity of the microbial cells reduces their ability to form a biofilm. It is shown that divalent metal ions are capable of increasing the hydrophobicity index of microbial cells and reducing biofilm formation. It is concluded that it is necessary to use materials with a negatively charged surface for biofilm-prevention measures.