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A material based on a (VCr)2AlC solid solution has been obtained for the first time by self-propagating high-temperature synthesis from a powder reaction mixture of vanadium(V) and chromium(III) oxides with aluminum and carbon (graphite). The synthesized material has been studied by X-ray diffraction and microstructural analyses. It has been shown that the product also contains vanadium and chromium carbides and intermetallics. The presence of these phases seems to be associated with the nonequilibrium character of the synthesis process due to a short “lifetime” of melt and its fast cooling and crystallization. The synthesized material is an electrical conductor, which demonstrates a metallic character of conductivity throughout the entire measured temperature range of 300–1300 K. The room-temperature specific resistance of the composite material based on a (Cr,V)2AlC solid solution is 1.14 µΩ m, which is higher than the specific resistance of the materials based on the Cr2AlC and V2AlC MAX phases. The microhardness of the synthesized material is 6.9 GPa.

High-temperature synthesis of cast composite materials in the Cr–Mn–Al–C system with various ratios between the Cr2AlC MAX phase and chromium and manganese aluminides and carbides was studied. Experiments were performed in a universal 3-L reactor under argon pressure Р = 5 MPa. Mixtures of powders of chromium(III) and manganese(II, IV) oxides and calcium peroxide with aluminum (ASD-I) and carbon were used as a charge. The synthesis features and the phase composition and microstructure of the target products are significantly influenced by the reactant ratio in the charge. At the stoichiometric ratio of the components corresponding to the Cr2AlC phase, a cast composite material consisting of the Cr2AlC MAX phase, chromium carbides Cr7C3 and Cr3C2, and chromium aluminide Cr5Al8 is formed. In the course of combustion of the charge with the component ratio corresponding to the Mn2AlC phase, a cast composite material consisting of manganese carbides (Mn3AlC, Mn0.545Al0.42C0.035) and aluminide (MnAl) is formed. When these compositions are combined in an 0.75 : 0.25 ratio, the final product is a composite material consisting of a solid solution based on the Cr2AlC MAX phase, manganese carbides (Mn3AlC), and chromium aluminides (Cr2Al). When these compositions are combined in an 0.5 : 0.5 ratio, the final product is a composite material consisting of the manganese-doped Cr2AlC MAX phase and of manganese (Mn14Al86, Mn22.5Al77.5) and chromium (Cr5Al8) aluminides. The final products were characterized by X-ray diffraction and local microstructural analysis.

–A material based on the V2AlC MAX phase has been obtained for the first time by the method of self-propagating high-temperature synthesis (SHS) using a reaction mixture of vanadium oxide(V) and (IV) powders with aluminum and carbon (graphite). The obtained material was characterized by X-ray diffraction and energy-dispersive X-ray spectroscopy. The Rietveld method was used to perform quantitative analysis. The synthesized material based on the V2AlC MAX phase is an electrical conductor that demonstrates the metallic behavior of conductivity in the entire measured temperature range of 300–1300 K in the vacuum of 2 × 10–3 Pa. It has been suggested that the V2AlC phase makes a decisive contribution to the electrical resistance of the synthesized material that may be caused by the formation of V2AlC nanolaminate grains contacting with each other in the bulk of the material.

It is known that materials based on MAX phases possess a large potential for use in aerospace, automobile, and industrial spheres because they have a unique combination of features of both metals and ceramics with high mechanical, chemical, thermal, and electrical properties. In this work, the experimental results of fabricating cast materials in the Cr–Al–C system with different ratios between the Cr2AlC MAX phase and chromium aluminides and carbides by SHS metallurgy are presented. The experiments were performed in an SHS reactor 3 L in volume at an initial inert gas (argon) pressure of 5 MPa. The synthesis was performed based on chemically coupled reactions: weakly exothermic (heat acceptor)—Cr2O3/3Al/C and strongly exothermic (heat donor)—3CaO2/2Al. The experimental results have good correlation with the preliminary thermodynamic calculations. It is shown that, when varying the composition of initial mixtures, it is possible to substantially affect the calculated and experimental synthesis parameters, as well as the phase composition and microstructure of final products. Optimal synthesis conditions of the material providing the maximal yield of the Cr2AlC phase in the ingot composition are established. The determining factor affecting the Cr2AlC content in the product is the occurrence time of the liquid phase under the synthesis conditions. It is shown that the maximal content of the Cr2AlC MAX phase and target product yield are attained at the 30% content of the strongly exothermic additive (3CaO2/2Al) in the initial charge.

Using the method of self-propagating high-temperature synthesis (SHS metallurgy), cast composite materials were produced in the Cr–Ti–B system. The experiments were carried out in universal SHS reactors with an initial argon pressure of Рin = 5 MPa. Mixtures of CaCrO4, TiO2, Al, and B powders were used as batch. It was shown that by varying the mass ratio α of CaCrO4/2Al/2B and 3TiO2/4Al/6B mixtures in a batch, it is possible to significantly affect the synthesis patterns, phase composition, and microstructure of the target products. The initial mixtures are capable of burning in the range of α 0–20%. The phase separation limit occurs at α = 15%. The introduction of a highly exothermic CaO2 + Al additive into the mixture made it possible to expand the phase separation limit to α = 20%. As α increases, the amount of titanium boride in the final product increases. The resulting composite material consists of titanium-chromium boride distributed in a matrix of chromium boride. The synthesized materials were characterized by X-ray and local microstructural analysis. The structural phase states of the target products produced under various conditions were studied.

Experimental data are presented on the high-temperature synthesis of cast composite materials in the Cr–Al–C system with different relative amounts of the MAX phase Cr2AlC and chromium carbides and aluminides. The experiments were carried out in multipurpose self-propagating high-temperature synthesis (SHS) reactors at an argon pressure p = 5 MPa. The starting mixtures consisted of calcium chromate (CaCrO4), aluminum (ASD-1), and carbon powders. It has been shown that varying the percentage of carbon in the starting mixture may have a significant effect on the synthesis process and the phase composition and microstructure of the final products. It has been found that, in the case of the stoichiometric starting mixture composition, the synthesis yields cast composite materials consisting predominantly of the MAX phase Cr2AlC and containing the lower chromium carbide Cr7C3 and the chromium aluminide Cr5Al8. The addition of excess (superstoichiometric) carbon to the starting mixture leads to an increase in the percentage of the MAX phase Cr2AlC in the synthesis product, disappearance of the chromium aluminide Cr5Al8, and the formation of the higher chromium carbide Cr3C2 instead of the lower carbide. The final synthesis products have been characterized by X-ray diffraction and local microstructural analysis. The structure and composition of the synthesis products obtained under various conditions have been determined.

A cast material based on the Nb2AlC MAX phase is formed by SHS metallurgy. The synthesis is performed using the Nb2O5–Al–C mixture with the CaO2–Al high-energy additive. The results of thermodynamic calculations correlate with the experimental data. The substantial influence of the CaO2–Al additive on the thermodynamic parameters and phase composition of the product is established. It is shown that the synthesis using mentioned mixtures occurs in a stationary mode with the formation of a steady combustion wave. The combustion rate increases from 6 to 12 mm/s with an increase in the additive content, and the product yield into the ingot increases from 30 to 47% (up to 15 wt % additive) and then decreases. The variation in the composition of initial mixtures can substantially affect both the synthesis parameters and the phase composition of products. The optimal synthesis conditions of the materials that provide the maximal yield of the Nb2AlC MAX phase in the ingot composition are established. The determining factor that affects the Nb2AlC content in the product is the liquid-phase lifetime under the synthesis conditions. It is shown that the maximal amount (67 wt %) of the Nb2AlC phase is attained with the content of the high-energy additive in the initial charge of 15 wt %.

A cast material based on the Nb2AlC MAX phase was obtained by SHS metallurgy. Synthesis was carried out from the Nb2O5– Al–C mixture with a high-energy CaO2–Al additive. Thermodynamic calculation results correlate well with experimental data. It was found that the CaO2–Al additive content has a substantial effect on the thermodynamic parameters and phase composition of the final product. It was shown that synthesis from the specified mixtures passed in a stationary mode with steady combustion wave. Increasing the additive content leads to increasing combustion rate (from 6 to 12 mm/s), and product yield to ingot increases (from 30 to 47 %) up to 15 wt.% of the additive and then decreases. Variation in the composition of initial mixtures can provide a significant impact on both synthesis parameters and final product phase composition. Optimal conditions of material synthesis to ensure maximum yield of the Nb2AlC MAX phase in the ingot composition were determined. The liquid phase lifetime during synthesis is a determining factor influencing the Nb2AlC content in the final product. It is shown that the maximum Nb2AlC phase amount (67 wt.%) is reached with 15 wt.% of the high-energy additive in the initial charge.

The regularities of synthesis by the SHS metallurgy method of cast materials in the Mo-W-Si system are studied. The experiments were carried out in SHS reactors with a volume of 3, 20 and 30 L under the pressure of an inert gas (argon) P = 5 MPa. In the experiments, high-calorie mixtures of molybdenum (6) and tungsten (6) oxides with aluminum and silicon were used. Thermodynamic calculation of combustion parameters of the initial systems according to the Thermo program showed that they have high adiabatic combustion temperatures exceeding the melting points of the initial reagents and final products of synthesis. Studies have shown a strong effect of the ratio of the initial reagents on the regularities of synthesis. Cast (ingots) single-phase disilicides of molybdenum (MoSi2) and tungsten (WSi2), as well as their solid solutions MoSi2–WSi2, are obtained with any given ratio between them. Their microstructure and elemental and phase composition were investigated. Optimal modes of mechanical conversion of the obtained ingots of the target products into the powders of the required fractions are developed. The influence of the composition of composites on the strength and oxidation of sintered samples in air at different temperatures was studied. It was shown that sintered composites from MoSi2–WSi2 solutions have higher strength and are less susceptible to oxidation compared to ceramics obtained by solid-phase sintering from powders of individual MoSi2 and WSi2.

In this paper, we studied the reaction mechanism of chemical transformations of the initial components in the combustion wave of MoO3/TiO2/Al/Si mixtures of the thermite type in the synthesis of molded molybdenum disilicide (MoSi2) and binary molybdenum titanium silicates ((MoTi)Si2). Syntheses were carried out in a high-temperature synthesis reactor at an initial argon pressure of P0 = 5 MPa. The effect of the ratio of initial reagents and geometric factors on the laws of synthesis of these materials was experimentally studied. The intervals of the component ratios, at which molybdenum and titanium silicides can be synthesized with specified compositions, are determined. We carried out experiments on stopping the combustion front. The chemical transformation of the components of the initial MoO3/TiO2/Al/Si mixtures in the combustion wave is shown to proceed in stages, and chemical reactions can be considered as chemically conjugated processes. The obtained results provide the scientific basis for the creation of promising molded silicide ceramics with high performance properties.

This paper reports the preparation of cast dimolybdenum pentaboride by a self-propagating high-temperature synthesis (SHS) metallurgy method. Experiments were carried out in SHS reactors at an initial excess gas (Ar) pressure p0 = 5 MPa. In the experiments, we used thermite-type starting mixtures consisting of molybdenum oxide, aluminum, boron oxide, and elemental boron powders. The combustion of such mixtures yields two types of final product: Mo2B5 and Al2O3. The combustion temperatures of the starting mixtures used in our experiments have been shown to exceed the melting points of the final products, which are thus formed in a liquid (cast) state. Under the effect of gravity, the heavier phase Mo2B5 settles down to form a lower ingot, whereas the lighter phase Al2O3 forms an upper ingot. The synthesis products have been characterized by X-ray diffraction and local microstructural analysis. The results demonstrate that the composition and amount of the starting mixture have a significant effect on the synthesis parameters and the composition and microstructure of the Mo2B5. We have optimized conditions for the preparation of single-phase cast dimolybdenum pentaboride.

A series of novel 4-aminobenzofuroxan derivatives containing aromatic/aliphatic amines fragments was achieved via aromatic nucleophilic substitution reaction of 4,6-dichloro-5-nitrobenzofuroxan. The quantum chemistry calculations were performed to identify the factors affecting the regioselectivity of the reaction. The formation of 4-substituted isomer is favored both by its greater stability and the lower activation barrier. Antimicrobial activity of the obtained compounds has been evaluated and some of them were found to suppress effectively bacterial biofilm growth. Fungistatic activity of 4-aminobenzofuroxans were tested on two genetically distinct isolates of M. nivale. The effect of some benzofuroxan derivatives is likely to be more universal against different varieties of M. nivale compared with benzimidazole and carbendazim. Additionally, their anti-cancer activity in vitro has been tested. 4-aminofuroxans possessing aniline moiety showed a high selectivity towards MCF-7 and M-HeLa tumor cell lines. Moreover, they exhibit a significantly lower toxicity towards normal liver cells compared to Doxorubicin and Tamoxifen. Thus, benzofuroxans containing aromatic amines fragments in their structure are promising candidates for further development both as anti-cancer and anti-microbial agents.

Soft rot caused by Pectobacterium species is a devastating plant disease poorly characterized in terms of host plant responses. In this study, changes in the transcriptome of tobacco plants after infection with Pectobacterium atrosepticum (Pba) were analyzed using RNA-Seq. To draw a comprehensive and nontrivially itemized picture of physiological events in Pba-infected plants and to reveal novel potential molecular &ldquo, players&rdquo, in plant&ndash, Pba interactions, an original functional gene classification was performed. The classifications present in various databases were merged, enriched by &ldquo, missed&rdquo, genes, and divided into subcategories. Particular changes in plant cell wall-related processes, perturbations in hormonal and other regulatory systems, and alterations in primary, secondary, and redox metabolism were elucidated in terms of gene expression. Special attention was paid to the prediction of transcription factors (TFs) involved in the disease&rsquo, s development. Herewith, gene expression was analyzed within the predicted TF regulons assembled at the whole-genome level based on the presence of particular cis-regulatory elements (CREs) in gene promoters. Several TFs, whose regulons were enriched by differentially expressed genes, were considered to be potential master regulators of Pba-induced plant responses. Differential regulation of genes belonging to a particular multigene family and encoding cognate proteins was explained by the presence/absence of the particular CRE in gene promoters.

A review of publications on the structure, properties, fabrication methods, and application fields of materials based on the Cr2AlC MAX phase is given. It is noted that the most promising method of formation of such materials is self-propagating high-temperature synthesis (SHS), one of the directions of which is SHS metallurgy. A powder mixture of chromium III and chromium VI oxides of the analytical grade, aluminum of ASD-1 grade, and carbon is used as the base charge in investigations. The adiabatic combustion temperature and composition of final products is calculated using the THERMO special program. Experiments were performed in an SHS reactor with volume V = 3 dm3 under the initial pressure of inert gas (Ar) P0 = 5 MPa. The influence of the ratio of initial reagents on SHS parameters (the combustion rate, pressure increment, and yield of the target product), composition, and microstructure of target products is investigated experimentally. A scientific approach of the formation of cast materials in the Cr–Al–C system consisting of the Cr2AlC MAX phase and phases Cr3C2 and Cr5Al8 by the SHS metallurgy method is developed. The structural-phase states of target products are studied. It is established experimentally that, varying the content of initial reagents (aluminum and carbon) in the charge, it is possible to substantially affect the synthesis regularities, composition, and microstructure of final products. An increase in the content of the Cr2AlC MAX phase in the final product and a decrease in the Cr5Al8 content occur with an increase in the carbon content (above stoichiometric) in the initial mixture. An increase in the aluminum content (above stoichiometric) in the initial mixture leads to an increase in the content of the Cr2AlC MAX phase in the final product and a decrease in the content of the Cr3C2 phase.

The possibility of combustion of a mixture of chromium peroxide with aluminum nitride is shown experimentally. The effect of initial pressure of nitrogen and ratio of reagents on an average linear burning rate, as well as on a relative mass loss in the combustion of a CrO3/AlN mixture is studied. The concentration limits of the burning rate of the test mixture are determined. The microstructure and phase and chemical compositions of the combustion products of the chromium–nitride-aluminum mixture are described.

Cast materials based on Nb2AlC MAX phase were prepared by metallothermic self-propagating high-temperature synthesis (SHS) under 5 MPa of Ar pressure from green mixtures containing Nb2O5, Al, and C powders, and additive of CaO2 + Al blend as a heat-generating agent. Variation in the amount (α) of the additive markedly affected the process parameters and phase composition of combustion products. An increase in α led to an increase in the combustion temperature. A key factor responsible for successful phase separation in the melt is the lifetime of the liquid phase. A maximum content of Nb2AlC MAX phase in the ingot (67 wt%) was reached under optimized conditions (α = 15%).

The combustion of a highly exothermic mixture of calcium chromate with aluminum and boron has been studied. It has been shown that these mixtures are able to burn in a wide range of reactant ratios. The autowave chemical transformation is accompanied by decomposition of calcium chromate, the chemical reaction of the decomposition products with aluminum and boron, the formation of a two-phase melt of the combustion products with its subsequent gravity separation, and crystallization of the layers. The results of the study may be useful for obtaining chromium borides.

In the present study, we attempted to elucidate if the harmful phytopathogenic bacteria of Pectobacterium genus (P. atrosepticum) possess the enzymes for oxidation of phenolic compounds. Polyphenol oxidase (laccase) activity was revealed in P. atrosepticum cell lysates. Using bioinformatic analysis, an ORF encoding a putative copper-containing polyphenol oxidase of 241 amino acids with a predicted molecular mass of 25.9 kDa was found. This protein (named Pal1) shares significant level of identity with laccases of a new type described for several bacterial species. Cloning and expression of the pal1 gene and the analysis of corresponding recombinant protein confirmed that Pal1 possessed laccase activity. The recombinant Pal1 protein was characterized in terms of substrate specificity, kinetic parameters, pH and temperature optimum, sensitivity to inhibitors and metal content. Pal1 demonstrated alkali- and thermo-tolerance. The kinetic parameters Km and kcat for 2,6-dimethoxyphenol were 0.353 ± 0.062 mM and 98.79 ± 4.9 s-1 , respectively. The protein displayed high tolerance to sodium azide, sodium fluoride, NaCl, SDS and cinnamic acid. The transcript level of the pal1 gene in P. atrosepticum was shown to be induced by plant-derived phenolic compound (ferulic acid) and copper sulfate.

Our study is the first to consider the changes in the entire set of matrix plant cell wall (PCW) polysaccharides in the course of a plant infectious disease. We compared the molecular weight distribution, monosaccharide content, and the epitope distribution of pectic compounds and cross-linking glycans in non-infected potato plants and plants infected with Pectobacterium atrosepticum at the initial and advanced stages of plant colonization by the pathogen. To predict the gene products involved in the modification of the PCW polysaccharide skeleton during the infection, the expression profiles of potato and P. atrosepticum PCW-related genes were analyzed by RNA-Seq along with phylogenetic analysis. The assemblage of P. atrosepticum biofilm-like structures—the bacterial emboli—and the accumulation of specific fragments of pectic compounds that prime the formation of these structures were demonstrated within potato plants (a natural host of P. atrosepticum). Collenchyma was shown to be the most “vulnerable” tissue to P. atrosepticum among the potato stem tissues. The infection caused by the representative of the Soft Rot Pectobacteriaceae was shown to affect not only pectic compounds but also cross-linking glycans, the content of the latter was increased in the infected plants compared to the non-infected ones.

Experimental data are presented on the high-temperature synthesis of cast inorganic materials in the MgO–Al2O3 system. Experiments were carried out in multipurpose self-propagating high-temperature synthesis (SHS) reactors at an argon pressure p = 5 MPa. The starting mixtures used in the experiments consisted of molybdenum(VI) and magnesium(II) oxides and aluminum. It has been shown that, varying synthesis parameters, one can control the phase composition and microstructure of the final oxide products. We have optimized synthesis conditions for the preparation of single-phase magnesium aluminate spinel, MgAl2O4. The SHS products have been characterized by X-ray diffraction and local microstructural analysis.

This work investigates the regularities of autowave chemical transformation of MoO3/Al/AlN mixture, gravity separation of its combustion products, and formation of composition and structure of end product (aluminum oxynitride). It is demonstrated that the mixtures of MoO3, Al and AlN are capable of burning in wide ranges of reagent ratios. In the general case, this process is composed of three consecutive stages: stage 1—combustion and chemical transformation of MoO3, Al, and AlN mixture into two-phase melt of end products (autowave synthesis); stage 2—gravity separation of combustion products (metallic and oxide phases), where two layers are generated: upper layer of “light” oxynitride (Al2O3–AlN) and bottom layer of “heavy” intermetallic compound (Mo–Al); stage 3—cooling and generation of phase composition and crystalline structure of metallic and oxide layers. It is established that variation of the aluminum content in the initial mixture at constant content of nitride additive significantly influences the combustion and autowave chemical transformation of the mixture and the phase composition and structure of the end product (aluminum oxynitride). Optimum compositions are determined for obtaining aluminum oxynitrides with high nitrogen content (up to 6–9 wt %) and impurity content (Al7O3N5 and AlN) below 3 wt %. The obtained cast aluminum oxynitride and method of its production are promising for production of high-strength transparent ceramics.

SHS-Metallurgy methods were used to obtain samples in the form of aluminum oxynitride Al5O6N ingots (AlON) using mixtures of the thermit type. The experiments were performed in SHS reactors at initial nitrogen pressure 5 MPa. The optimal conditions for the synthesis of the most stable phase of aluminum oxynitride Al5O6N were determined. Regimes were developed for comminuting the synthesized ingots into powder with definite fractions. Spark plasma sintering (SPS) was used to obtain from them experimental samples with high density, hardness, and transparency.

The review of the results obtained by the authors in synthesis of cast composite materials by the methods of SHS metallurgy is made. The main attention is paid to synthesis of heat-resistant materials based on intermetallic compounds of nickel and titanium and niobium silicides as well as tungsten-free hard alloys based on titanium and chromium carbides. The parameters allowing one to govern the process, material structure and composition were determined. Practical application was specified.

Cast ceramic composites were prepared by metallothermic SHS under elevated Ar pressure (5 MPa). Variation in green composition was used to affect the phase composition of combustion products. Under some optimized conditions, resultant ceramics can be obtained in the form of Al2O3–Cr2O3 solid solutions, Al2O3–Cr2O3 ∙ хZrO2 composites or single-phase Al2MgO4. Such materials seem promising for use in jewelry, process engineering (casting molds, cutting tools), and aerospace industry.

Cast aluminum oxynitrides were prepared by aluminothermic SHS under pressure of nitrogen gas and characterized by time-resolved XRD and chemical analysis. Burning velocity U, material loss caused by sputtering η1, and yield of target material into ingot η2 were measured as a function of nitrogen pressure P(N2). The nitrogen content of synthesized oxynitrides was made as high as 7 wt %. The results may turn helpful in designing high-strength transparent ceramics.

The intrusive growth, a type of plant cell elongation occurring in the depths of plant tissues, is characterized by the invasion of a growing cell between its neighbours due to a higher rate of elongation. In order to reveal the largely unknown molecular mechanisms of intrusive growth, we isolated primary flax phloem fibers specifically at the stage of intrusive growth by laser microdissection. The comparison of the RNA-Seq data from several flax stem parts enabled the characterization of those processes occurring specifically during the fiber intrusive elongation. The revealed molecular players are summarized as those involved in the supply of assimilates and support of turgor pressure, cell wall enlargement and modification, regulation by transcription factors and hormones, and responses to abiotic stress factors. The data obtained in this study provide a solid basis for developing approaches to manipulate fiber intrusive elongation, which is of importance both for plant biology and the yield of fiber crops.

The regularities for the autowave synthesis (SHS) of a cast oxide composite material (Al2O3–Cr2O3 · ZrO2) were studied by example of combustion of thermite-type systems under an inert gas pressure. The ratio of starting reagents with optimal zirconia content was determined for the synthesis of the desired product on the basis of analysis of published data and thermodynamic calculations (Thermo program). In the experiments, it was shown that combustion temperature and sample mass are the most important parameters influencing the composition and microstructure of the final product. Optimal conditions for the process control were defined. The final product includes solid solution Al2O3–Cr2O3 grains located on the boundaries of ZrO2 particles. The material is promising for production of machine parts working in conditions of intense wear and shock loads in corrosive environments at elevated temperatures (for example, sintering of ceramic cutting tools).

The process of self-propagating high-temperature synthesis of the Mo–Nb–Si silicides from the powder mixtures has been investigated. Based on performed experiments, the composition of powder mixtures as well as technological parameters are proposed which provide the synthesis of monosilicides MoSi2, NbSi2, and binary silicides Mo1−хNbxSi2 with different ratios of Nb/Mo by adding different contents of MoO3 and Nb2O5. Microstructure and phase compositions of the obtained silicide ingots are characterized by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and backscatter electron diffraction.

Composites in the MoSi2 + Si3N4 system containing 1.0, 2.5, and 5.0 wt % Si3N4 were synthesized by hot pressing at the temperature of 1650°C and the pressure of 30 MPa. Silicon nitride powders of two types of were used as reinforcing additives: one with isometric equiaxed crystals and one with fibrous structure. The samples were characterized by microstructural and phase analyses; the relative density and the flexural strength were determined. Composites with the flexural strength of up to 410 MPa were synthesized. The resistance to low-temperature oxidation of MoSi2 + Si3N4 composites in air at the temperature of 750°C was studied. The increase in the resistance to oxidation of composites with silicon nitride in air compared to pure molybdenum disilicide for both types of silicon nitride powders was established. For all the composites obtained, the parabolic oxidation rate constants were calculated.

Functional specialization of cells is among the most fundamental processes of higher organism ontogenesis. The major obstacle to studying this phenomenon in plants is the difficulty of isolating certain types of cells at defined stages of in planta development for in-depth analysis. A rare opportunity is given by the developed model system of flax (Linum usitatissimum L.) phloem fibres that can be purified from the surrounding tissues at the stage of the tertiary cell wall deposition. The performed comparison of the whole transcriptome profile in isolated fibres and other portions of the flax stem, together with fibre metabolism characterization, helped to elucidate the general picture of the advanced stage of plant cell specialization and to reveal novel participants potentially involved in fibre metabolism regulation and cell wall formation. Down-regulation of all genes encoding proteins involved in xylan and lignin synthesis and up-regulation of genes for the specific set of transcription factors transcribed during tertiary cell wall formation were revealed. The increased abundance of transcripts for several glycosyltransferases indicated the enzymes that may be involved in synthesis of fibre-specific version of rhamnogalacturonan I.

The activation energy of sintering process was calculated based on dilatometric studies of shrinkage processes (Mo,W)Si2 + Si3N4 composite ceramic. (Mo,W)Si2 powders was obtained by solid-phase solutions of 70 wt% MoSi2 and 30 wt% WSi2 by SHS in the ISMAN RAS. The concentration rate Si3N4 was from 1 to 15 wt.%. The sintering was carried out to 1850°C in Ar atmosphere the heating rate of 5, 10, 12 and 15°C/min by the way of dilatometer tests. Based on the differential kinetic analysis method (Friedman's method), the sintering process activation energy of (Mo,W)Si2 + Si3N4 were calculated. The two-stage sintering process and the dependence of the activation energy on the Si3N4 content was shown. Average value of 370 kJ/mol for Q was obtained.