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The calculation of the coefficients of magneto-optical absorption in semiconductors at different temperatures and pressures is carried out. A formula for the temperature dependence of the oscillations of the combined density of states by the Kane dispersion law is obtained. Mathematical modeling has been carried out that determines the magneto-optical absorption coefficient in semiconductors in the presence of external influences. A new method for determining the magneto-optical absorption coefficient in semiconductors in the presence of pressure and temperature is proposed. The correspondence of simulation results with experimental data is shown. [ABSTRACT FROM AUTHOR]

Electron paramagnetic resonance (EPR) spectra of Nb[sup 4+] ions in Li[sub 2]O-Nb[sub 2]O[sub 5]-P[sub 2]O[sub 5] glasses with different composition of oxide components have been investigated. The EPR spectrum shape analysis of Nb[sup 4+] (electron configuration 4d¹, electron spin S= 1/2) reveals the formation of triplet niobium binuclear complex (total electron spin S= 1) in glasses. The amount of Nb[sup 4+] ions in glasses reversibly changes with temperature and is explained via the mechanism of electron hopping between niobium ions in clusters. The dependence of the amount of Nb[sup 4+] ions upon Li[sub 2]O content has a maximal character, which implies that small amounts of Li[sup +] ions stabilize the Nb[sup 4+] pairs, but cause their disproportionation at higher concentrations of Li[sup +] ions in the glass. Quantum mechanical analysis of electronic and spin states of binuclear niobium clusters has been performed on model binuclear complexes, (HO)[sub 3]Nb-O-Nb(OH)[sub 3], [(HO)[sub 3]Nb-O-Nb(OH)[sub 3]]Li[sup +], and [(HO)[sub 3]Nb-O-Nb(OH)[sub 3]](Li[sup +])[sub 2] that exhibit the reversible disproportionation reaction Nb[sup 4+]- O-Nb[sup 4+] ... Nb[sup 3+]- O-Nb[sup 5+]. Triplet states of these complexes (total electron spin S = 1 ) have lower energies than singlet states (S=0), and Li[sup +] ions stabilize the binuclear niobium complex. We have found that electron spin densities on niobium ions change depending upon the shift of the bridging oxygen atom. Application of this theoretical modeling to the analysis of the experimental EPR spectrum in Li[sub 2]O-Nb[sub 2]O[sub 5]-P[sub 2]O[sub 5] glass concludes noncentrosymmetric structure of binuclear niobium complex with ∼0.1 Å offset of the bridging oxygen atom towards one Nb atom. [ABSTRACT FROM AUTHOR]

Acyclic diaminodiperoxides and cyclic azadiperoxides are synthesized by the reaction of 1,1-bis-(hydroperoxy)cycloalkanes with formaldehyde and primary arylamines in the presence of Sm-containing catalysts [SmCl3·6H2O, Sm(NO3)3·6H2O, SmCl3/γ-Al2O3, and Sm(NO3)3/γ-Al2O3]. The chemoselectivity of this three-component reaction depends on the position of the substituent (F,Cl) in the phenyl ring of the primary arylamines. Signals of the cyclic aminoperoxides were assigned considering the conformation dynamics of the tetraoxazocane cycle with two rigid peroxide bonds. The structure of the acyclic diaminodiperoxides was reliably determined by X-ray diffraction analysis. The synthesized acyclic diaminodiperoxides were found to exhibit anticancer activity. [ABSTRACT FROM AUTHOR]

We present a new giant magnetoresistance (GMR) material composed of polyaniline, polystyrene, sulfur, manganese acetylacetonate, lanthanum, and praseodymium chlorides. These compounds were mixed and processed mechanochemically to obtain thin films. External magnetic field of 6000 Oe increases conductivity of films by more than 300%. Analysis of transient current kinetics after application of constant voltage (10 V) to samples showed the existence of three types of charge carriers, which we identified as e-, H+, and Cl-. Contribution of functional groups of polyaniline and elemental sulfur S in the formation of the above charge carriers in this new GMR composite material is discussed. [ABSTRACT FROM AUTHOR]

Coordination polymers exhibiting magnetic properties can be considered as promising materials for magnetic applications. We obtained such materials by means pf mechanochemical incorporation of binuclear metal complexes Mn–O–Mn into polystyrene. Incorporation of binuclear manganese complexes was achieved by using substituted benzoquinones (organic acceptors) as intermediate ligands that react with manganese acetylacetonate and provide new coordination and stabilization of manganese in different valence states. Magnetic transitions in this system are due to reversible disproportionation process Mn3+–O–Mn3+⇔Mn2+–O–Mn4+ in the binuclear complex. The structure of the binuclear complex was obtained using ab initio calculations. [ABSTRACT FROM AUTHOR]

We report on mechanochemical synthesis and magnetic and electric properties of organic polymeric semiconductor that contains paramagnetic and ferromagnetic particles. As starting materials we used polyaniline (emeraldine base), polystyrene, FeCl3, and elemental sulfur. These components were chosen for the purpose of obtaining semiconductor polymer composite containing magnetic iron nanoparticles and having flexible thermomechanical properties. The presence of nanoparticles was evidenced by scanning electron microscopy. The value of conductivity of the Fe-doped polymer composite was increased by several orders of magnitude compared to the initial undoped polyaniline. Temperature dependence of the conductivity shows semiconductor character of the composite material. [ABSTRACT FROM AUTHOR]

By means of mechanochemical synthesis we obtained a coordination polymer containing binuclear manganese complexes with organic catechol/ortho-quinone ligands. The reaction system contained polystyrene, manganese acetylacetonate, and donor-acceptor mixture catechol/ortho-quinone. Electron paramagnetic resonance (EPR) and infrared spectroscopic data show that the binuclear manganese complex is covalently linked to the chain of polystyrene. Theoretical EPR spectrum analysis revealed a triplet state of the complex with two nonequivalent manganese ions coupled to each other by spin exchange. The type of magnetic coupling between manganese ions in this system is similar to the one in manganese based inorganic magnetic materials. [ABSTRACT FROM AUTHOR]

We investigated paramagnetic properties of binuclear niobium complexes Nb-O-Nb with two nonequivalent Nb4+ ions in lithium-niobium phosphate glasses sLNPGd, in the environment of catechol/ortho-quinone ligands and in polyethylene. Experimental electron paramagnetic resonance spectrum analysis revealed nonequivalent distribution of the charge and electron spin density between two Nb atoms. Mechanochemical interaction of LNPG with an organic donor-acceptor mixture catechol/ortho-quinone followed by organic solvent extraction leads to the formation of a new binuclear complex with catechol/ortho-quinone ligands. This complex can be further incorporated into polyethylene matrix to form the complex with properties close to the complex in LNPG. [ABSTRACT FROM AUTHOR]

We report on synthesis of Co, Ni, and Fe nanoparticles by the action of elastic wave pulses on solid phase sandwich type samples containing metal salt, reducing agent, polyethylene, and polyacrylamide. The formation of metal nanoparticles is evidenced by ferromagnetic resonance and scanning electron microscopy. The product yield for the nanoparticles formation has a threshold character with the pressure in the elastic wave pulse. The maximum amount of Co, Ni, and Fe nanoparticles is observed around 20 kbar of pressure in elastic wave pulses. The presence of polyacrylamide in reaction composites increases the stability of metal nanoparticles to oxidation by two orders of magnitude. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Chromium complexes, where ortho-quinone ligands are covalently linked to polymeric chains of polyethylene, polystyrene, and copolymer of ethylene and vinylacetate are studied. The results of infrared and electron paramagnetic resonance spectroscopic studies of chromium coordination polymers show that covalent linking of quinone ligands is accompanied by the change in the valence states of chromium Cr(III)↔Cr(IV)↔Cr(V). The ligand field of the triplet Cr4+ ion is close to the one in Cr-doped Y2SiO5, a laser material in the visible and infrared regions. Therefore some useful magnetic and/or optical properties in such transition metal coordination polymers can be expected. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This paper presents scientific and experimental data for low-firing hydraulic binders: hydraulic lime and Roman cement based on local mineral raw materials. The binders were prepared by firing representative samples of carbonate-clay magnesian raw materials from Tatarstan. Using X-ray diffraction, we identified the firing products, including a hydraulically active phase, and determined the structural characteristics of its minerals. The compositions of the binders were determined as functions of firing conditions. We examined the influence of the firing temperature and duration of magnesian raw materials in the preparation of binders on MgO activity and demonstrated for the first time the possibility of ensuring an active state of the MgO resulting from firing (up to 21%) and suppressing its negative effect on Roman cement and hydraulic lime hardening processes. [ABSTRACT FROM AUTHOR]

Corrosion resistance of aluminum and aluminum-based alloys is analyzed from the standpoint of their use for railroad transport (freight and passenger) in aggressive environments. The effect of alloying elements on the operating characteristics of the aluminum alloys is considered. The advantages of aluminum-based alloys with expected high corrosion resistance for replacing container and car steels are presented. [ABSTRACT FROM AUTHOR]

In this work, a new model has been developed for calculating the effect of a quantizing magnetic field on the temperature dependence of the two-dimensional combined density of states in direct-gap heterostructures with quantum wells. The temperature dependence of the oscillations of the two-dimensional combined density of states of the quantum well is explained by the thermal smearing of the Gaussian distribution function in a strong magnetic field. Based on the proposed new models, the Landau levels of charge carriers in a direct-gap quantum well are determined in a wide temperature range. The experimental results were interpreted using the oscillations of the combined density of states of the quantum well in a quantizing magnetic field. [ABSTRACT FROM AUTHOR]

A method of synthesis was developed for 1,5,3-dithiazepan(dithiazocan)-3-ylamines and 3,3′-bi-1,5,3-dithiazepane(dithiazocane) by hydrazines cyclocondensation with formaldehyde and α,ω-alkanedithiols (1,2-ethanedithiol, 1,3-propanedithiol) involving catalysts based on d- and f-elements. [ABSTRACT FROM AUTHOR]

This paper presents results of detailed studies of composite slag binders with mineral silica additions differing in reactivity. We have identified general trends and assessed the effects of composition, particle size, and binder hardening conditions on the normal consistency, paste setting time, hardening kinetics, strength, average density, and water absorption in composite slag binder stone. Using X-ray diffraction and scanning electron microscopy, we have identified the key features of structure formation in stone with mineral silica additions and examined the influence of additives on the composition and volume of the hardening products of composite slag binders. The results have been used to construct a model of the structure and structural elements of composite slag binder stone with mineral silica additions. [ABSTRACT FROM AUTHOR]

The author reflects on the beliefs and ideas connected with the wearing of veils, known as faranji, among Muslim women in Central Asia. The author states that there is persuasive evidence that could oppose the claims of some researchers that the wearing of the veil among women signifies male supremacy. She adds that the wearing of a veil could have more complex causes, such as beliefs that are linked with protecting women and children from imagined evil powers.

The article discusses the integration of pre-Islamic ideas into the system of Muslim values which brought about the phenomenon of women seclusion in Central Asia. According to the author, the practice of body covering as a religious adherence has been a common practice among different communities regardless of race and geographic location. Moreover, a discussion on the origin of the phenomenon of women seclusion is presented relative to many forms of ancient and contemporary religions.

The current problem of conveyor and cabinet drying of various materials is considered. Radiation infrared drying using nonlinear infrared radiation (IR) transducers based on a functional ceramic is studied. Use of IR of a special spectral composition and structure makes it possible to shorten processing duration considerably, to improve product quality, to simplify the design layout, and also to create conditions for mechanizing and automating production. [ABSTRACT FROM AUTHOR]

Off-design flow past waveriders is studied on the M∞ = 4 to 12 freestream Mach number range. Configurations based on the flows behind axisymmetric conical shocks are considered. The waverider geometry is determined by preassigning the transverse contour of the undersurfaces in the base section using power-law functions. The results are obtained by finite-volume solution of the Euler equations using higher-order Runge-Kutta TVD schemes. [ABSTRACT FROM AUTHOR]

Features of formation of an adverse longitudinal pressure gradient in a supersonic flow around a carrying body with a surface inclined at a constant angle to its symmetry plane have been numerically investigated within the framework of the Euler equations. A mathematical model of such bodies constructed on the basis of pieces cut from the surface of a backward-facing hyperelliptic cone is proposed. This model allows one to obtain a wide variety of carrying bodies. The data obtained were compared with the corresponding data for equivalent bodies with a plane downstream face. [ABSTRACT FROM AUTHOR]

The results of a numerical investigation of supersonic off-design flow past waveriders at the freestream Mach numbers M∞ = 4 and 8 are presented. Flow regimes with M∞ both greater and smaller than the design value Md are analyzed. Configurations based on the flows behind plane shocks and described by power-law functions are considered. The results are obtained by the finite-volume solution of the Euler equations using higher-order TVD Runge-Kutta schemes. [ABSTRACT FROM AUTHOR]

Emphasizes on the conceptual foundations of social policy during the emergence of market relations in Tajikistan. Increase in income differentiation; Provision of social guarantees to retired people and the handicapped; Market methods of economic management.

The types of tools for the primary and secondary tillage, sowing of agricultural crops and packing of the soil are established. It has been revealed that in order to reduce the number of necessary machines that fulfill the elements of technology, newly created machines should be combined and universal with replaceable tools and replaceable modules with various types of tools for tillage and agricultural crops seeding. To fulfill agro-technical requirements for depth of cultivation and seeding, as well as requirements for depth variation, estimated by standard deviation, during wide-coverage machines operating process based on dynamic, kinematic and static unit models, by representing the field surface relief as a two-dimensional random function, the widths of the replaceable modules for performing primary and secondary soil tillage and crop seeding are considered. Replaceable modules are attached to the frame of the tillage seeding machine through the hitch mechanism. The hitch mechanism parameters are proved by the use of static equations, which ensured the soil reaction on the balancing wheels within acceptable limits as required. [ABSTRACT FROM AUTHOR]

The types of tools for the primary and secondary tillage, sowing of agricultural crops and packing of the soil are established. It has been revealed that in order to reduce the number of necessary machines that fulfill the elements of technology, newly created machines should be combined and universal with replaceable tools and replaceable modules having various types of tools for tillage and agricultural crops seeding. To fulfill agro-technical requirements for depth of cultivation and seeding, as well as requirements for depth variation, estimated by standard deviation, during wide-coverage machines operating process based on dynamic, kinematic and static unit models, by representing the field surface relief as a two-dimensional random function, the widths of the replaceable modules for performing primary and secondary soil tillage and crop seeding are considered. Replaceable modules are attached to the frame of the tillage seeding machine through the hitch mechanism. The hitch mechanism parameters are proved by the use of static equations, which ensured the soil reaction on the balancing wheels within acceptable limits as it is required. [ABSTRACT FROM AUTHOR]

The article presents a study which identifies the polyphenol composition of Euphorbia canescens and E. franchetii. It states that the phenolic compounds in the aqueous fraction were tested using paper chromatography over a column of polyamide with elution by a CHCl3:MeOH gradient with an increased MeOH content. It mentions the compounds that were identified from their physicochemical properties including quercetin, kaempferol, and quercetin-3-rutinoside.

Ferromagnetic resonance (FMR) in the dependence on magnetic field orientation, and effect of the laser light on the magnetic ordering were studied in colossal magnetoresistance films, La1-xSrxMnO3 and La1-xBaxMnO3. The FMR linewidth increased with the decrease in temperature in La1-xSrxMnO3 films, and was nearly temperature independent in La1-xBaxMnO3, that was attributed to the different degree of magnetic homogeneity of the films. Layered structures La1-xBaxMnO3 on silicon with intermediate layer of SrTiO3 were characterized by FMR as highly homogeneous. From the orientation and temperature dependences of the FMR spectra, the effective magnetization, and effective anisotropy fields were estimated. The laser light illumination resulted in the change of FMR line shape and intensity, and was interpreted in terms of optically induced magnetic disordering and effective heating of the spin system. [ABSTRACT FROM AUTHOR]

In continuation of this research, extracts of the plant were analyzed by HPLC on a chromatograph (CombiFlash RF Teledyne ISCO, Inc., USA) with a UV detector to identify terpenoid compounds from the aerial part of I F. ferulioides i and quantitatively determine them by comparing UV spectra of the compounds being analyzed with those in the chromatograph software databases [[1]]. Korovin (Apiaceae) is a tall perennial plant that is collected during flowering in Xinjiang-Uyghur Autonomous Region of China. Previously, 13 sesquiterpenoid and phenolic compounds were isolated and identified by us from the aerial part of I F. ferulioides i . [Extracted from the article]

A sharp microwave response centered at zero magnetic field was observed in manganese- and iron-doped Na[sub 2]O-CaO-MgO-SiO[sub 2] glasses with phase opposite to the normal Mn[sup +2] and Fe[sup +3] paramagnetic signals. The response can be described as magneto-induced microwave conductivity in the dielectric glass that derives from spin-dependent charge migration within the first coordination sphere of the paramagnetic ion. In contrast to the spin-polarized tunneling in ferromagnets between different valence states of metals, the observed effect is due to spin-dependent tunneling that occurs in the vicinity of manganese or iron in diluted paramagnetic systems. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The packing in the crystal involved intermolecular O-H...O H45;bonds between the hydroxyl H atom of the starting molecule and the carbonyl O atom of a molecule translated by a 2 SB 1 sb screw axis along the I b i axis. Fraction F (10.0 g) was separated by CC (ODS, MeOH-H SB 2 sb O) into 15 subfractions (ODS1-15) that were purified and separated by semi-preparative RP HPLC to produce compounds B 3 b (5.6 mg) and B 4 b (5.8 mg). Fraction D (15 g) was rechromatographed over a column (ODS, MeOH-H SB 2 sb O) to produce six subfractions (ODS1-6) that were separated by semi-preparative reversed-phase HPLC (RP HPLC) to afford compounds B 1 b (8.0 mg) and B 3 b (6.0 mg). [Extracted from the article]

Photoluminescence of amorphous SiO nanoparticles compressed in the form of tablets is studied under exposure to UV radiation. The observed luminescence spectrum is a broad band extending from the excitation wavelength to 700 nm and with a maximum at ~470 nm. The spectrum can be decomposed into two Gaussian components with maxima at ~460 and ~530 nm. As the pressure applied for sample preparation increases, the integrated intensities of these bands change in opposite directions-the intensity of the short-wavelength band increases, while that of the long-wavelength band decreases. It is concluded that these bands are due to different luminescence centers of silicon dioxide located on the surface and in the bulk of SiO nanoparticles. [ABSTRACT FROM AUTHOR]

Among the natural compounds representing medicinal benefits significant place belong to plant phenolics. A wide range of biological action and low toxicity allows include them in a number of promising medicinal formulations in this regard. Therefore, the search for plants containing phenolics, the development of methods for their isolation, the determination of their chemical structure, and the study of biological activity is an actual problem in bioorganic chemistry. In this regard, the aimof our study is study the chemical composition of the polyphenols of the Rhus glabra(Smooth sumac) plant, in order to search for new sources of raw materials rich in biological active compounds growing on the territory of the Republic of Uzbekistan. The leaves of R.glabra were collected at the end of the vegetative period, air dried in the shade. 70% aqueous acetone used for full extraction of phenolics, afterevaporation of acetone under vacuum, the aqueous residue sequentially partitioned with chloroform and ethyl acetate. Ethyl acetate fraction, containing main amount of phenolics (controlled by Folin-Ciocalteu's reagent) vacuum concentrated as far as possible and pool of phenol compounds precipitated by adding of chloroform. The yield of total phenolics was 12% of the air-dry weight of the raw material. Qualitative reactions and TLC methods revealed the presence of flavonols, phenolic acids and tannins in the composition of the total polyphenols. RP-HPLC with corresponding standards and LCMS/MS shown, that the main constituent of prepared phenolic fraction there was a group of the hydrolysable tannins - poly galloyl glucose. In Table below listed the identified compounds. [ABSTRACT FROM AUTHOR]

Using the method of cyclic voltammetry the possibility of formation of the Pd(II) complex with triarylphosphine ligand on the gold electrode surface is shown resulting from the following sequence of reactions: (1) formation of the self-organized monolayer (SOM) of di(11-mercaptoundecyl)disulfide on the Au surface; (2) esterification of terminal hydroxy groups of the formed SOM with diphenyl(p-carboxyphenyl) phosphine; (3) formation of the complex compound fixed on the surface by treatment of the modified electrode with solution of PdCl2 in CH3CN. The possibility of electrocatalytic reduction of iodobenzene on the gold electrode with participation of the obtained Pd(II) complex is demonstrated. [ABSTRACT FROM AUTHOR]

Laser-induced birefringence in silicate glasses is investigated. The birefringence is found at the boundary between the irradiated and unirradiated regions in the glass after long-term exposure to N2 laser radiation (λ = 337 nm). Along with the stationary effect, a temporal (transient) change in the polarization of the probe beam is also observed, which arises only during UV irradiation and vanishes when the irradiation is over. The birefringence found is explained by the occurrence of anisotropy at the boundary between the irradiated and unirradiated regions of a glass due to a local change in the glass density in the irradiated region. [ABSTRACT FROM AUTHOR]

The results of a numerical and analytical investigation of steady-state supersonic inviscid flows in corners formed by intersecting compression wedges are presented. The flows considered are symmetric about the corner bisector. The distinctive features of flow pattern formation related with the reflection of wedge-generated shocks from the bisector plane are studied. The wedge angles at which transition from regular to irregular shock reflection occurs are determined both numerically and analytically using the criteria available for plane flows; the data thus obtained are found to be in agreement. Flow patterns with irregular shock reflection, namely, single, transitional, and double Mach, as well as von Neumann reflection, are identified; they are similar to the known types of reflection for plane quasi-steady-state flows. Varieties of these types not observed in the plane flows are found to exist. The effects of the angle of inclination of the plane surfaces of the corner to the freestream direction, the sweep angle of the leading edges, and the dihedral angle are investigated. Some previously unknown parameters of corner configurations for which transition may occur in accordance with the von Neumann criterion are determined. [ABSTRACT FROM AUTHOR]

This article investigated the effects of a quantizing magnetic field and temperature on Fermi energy oscillations in nanoscale semiconductor materials. It is shown that the Fermi energy of a nanoscale semiconductor material in a quantizing magnetic field is quantized. The distribution of the Fermi–Dirac function is calculated in low-dimensional semiconductors at weak magnetic fields and high temperatures. The proposed theory explains the experimental results in two-dimensional semiconductor structures with a parabolic dispersion law. Fermi energy oscillations in quantum wells (quantum wells, mainly GaAs/GaAlAs heterostructures) for measuring two-dimensional electron gases m = 0.0665m0, N = 8.1011 cm2, G = 0.5 meV and T = 6 K were shown in different magnetic fields and constant temperature, to compare the theory with the experiment. It can be seen that Fermi energy at a constant electron density is quantized in a very strong way as a function of B in theoretical and experimental plots. [ABSTRACT FROM AUTHOR]

The results of numerical and experimental studies of a model configuration of a hypersonic vehicle realizing the principle of compression convergence of the entire jet captured by an air-intake from the oncoming stream are presented. The external flow past a convergent air-intake integrated with a transversely-concave nose compression surface is investigated over the freestream Mach number range from 2 to 6. The salient features of the flow pattern near air-intakes with sidewalls of different length are established and the influence of a limitation on the lateral flow near the external compression wedge on the flow rate characteristics of the air-intake is established. The numerical calculations are performed within the framework of the inviscid gas model using higher-order TVD schemes; the calculated and experimental results are compared. [ABSTRACT FROM AUTHOR]

The main function of matrix metalloproteinases is the degradation of the extracellular matrix and participation in signal transduction. In addition, it is known that they are involved in all stages of the progression of the tumor process. The activity of metalloproteinases can be regulated by interactions with specific inhibitors of matrix metalloproteinases, so the latter are also able to participate in tumor growth. The genes of matrix metalloproteinases and their inhibitors, as well as many other genes, are characterized by polymorphism. We have analyzed the frequency distribution of the alleles and genotypes of the polymorphic loci rs1799750 and rs494379 of the MMP1 gene, rs2285053 of the MMP2 gene, rs3025058 of the MMP3 gene, rs3918242 and rs17576 of the MMP9 gene, rs2276109 of the MMP12 gene, rs8179090 of the TIMP2 gene, and rs9619311 of the TIMP3 gene in 314 patients with gastric cancer, as well as in 339 unrelated healthy individuals from the Republic of Bashkortostan. It was shown that the markers of the increased risk of developing gastric cancer are the genotypes rs1799750*1G/2G of the MMP1 gene and rs2276109*A/A of the MMP12 gene for Tatars and the genotype rs9619311*T/T of the TIMP3 gene for Russians. The association of the rs494379*G allele of the MMP1 gene and increased risk of developing malignant tumors of the stomach were reported in men. Using the APSampler algorithm, we identified combinations of alleles/genotypes associated with an increased and a reduced risk of developing gastric oncopathologies. The data obtained confirm the influence of the studied polymorphic variants of the genes of matrix metalloproteinases and their tissue inhibitors on the risk of developing gastric cancer and are important for understanding the genetic structure of the studied pathology. [ABSTRACT FROM AUTHOR]

Electrical conductivity oscillations, magnetic susceptibility oscillations and electronic heat capacity oscillations for narrow-gap electronic semiconductors are considered at different temperatures. A theory is constructed of the temperature dependence of quantum oscillation phenomena in narrow-gap electronic semiconductors, taking into account the thermal smearing of Landau levels. Oscillations of longitudinal electrical conductivity in narrow-gap electronic semiconductors at various temperatures are studied. An integral expression is obtained for the longitudinal conductivity in narrow-gap electronic semiconductors, taking into account the diffuse broadening of the Landau levels. A formula is obtained for the dependence of the oscillations of longitudinal electrical conductivity on the bandgap of narrow-gap semiconductors. The theory is compared with the experimental results of Bi 2 Se 3 . A theory is constructed of the temperature dependence of the magnetic susceptibility oscillations for narrow-gap electronic semiconductors. Using these oscillations of magnetic susceptibility, the cyclotron effective masses of electrons are determined. The calculation results are compared with experimental data. The proposed model explains the experimental results in p-Bi 2 − x Fe x Te 3 at different temperatures. [ABSTRACT FROM AUTHOR]

La0.60Sr0.40MnO3 (LSMO) thin films of varying thickness from 12 to 55 nm were deposited using the pulsed-laser deposition technique onto single-crystalline SrTiO3 (STO) and STO-buffered Si substrates. The Tc of LSMO films grown on STO-buffered Si substrates decreases faster than films directly grown on STO with decreasing film thickness. The LSMO/STO film with thickness of 55 nm shows Tc at about 360 K, which is close to the bulk value, whereas Tc LSMO film on STO-buffered Si film of similar thickness is reduced to 320 K. This difference is attributed to the strain and interfacial disorders in LSMO film on STO/Si. The film surface morphology is influenced by the film thickness. Oxygenation of LSMO films on STO-buffered Si affects the Tc minimally but improved the overall magnetization of the films due to better oxygenation, which is also the case for postannealing the sample at elevated temperatures. The thermomagnetic history effects observed in LSMO films of STO-buffered Si indicate the presence of inhomogeneity, mostly at the interface, which influences the magnetic properties significantly. [ABSTRACT FROM AUTHOR]

We report on the magnetic properties of epitaxial La0.7Ba0.3MnO3 and La0.7Sr0.3MnO3 films on Si (100) and Si (111) substrates using SrTiO3 template layer, which demonstrate magnetic and electrical properties at and above room temperature. The magnetization data show magnetic transition and magnetic hysteresis at and above room room temperature. The films show well-defined magnetic domains. The ferromagnetic resonance studies show anisotropic effects related to ferromagnetic properties of films. The smaller grain size of about 20 nm in manganite films on SrTiO3/Si may be one of the reasons to minimize the strain effect through strain relaxation at the interface between SrTiO3 and manganites through the formation of three-dimensonal islands. [ABSTRACT FROM AUTHOR]

V[sup 4+] doped YA10[sub 3], LaGaO[sub 3], and CaYA1O4 crystals (3 d¹ ion in octahedral coordination) have been grown and characterized as potential broadband laser materials using optical and electron paramagnetic resonance techniques. The effect of charge compensation on the vanadium valence state and spectroscopic properties of the materials are discussed. [ABSTRACT FROM AUTHOR]

The spectra of luminescence and magnetic circular polarization of luminescence of praseodymium–yttrium aluminum garnet Pr3+ : Y3Al5O12 (PrYAG) are studied in the visible spectral region at temperature T = 300 K. An analysis of spectral dependences of magnetooptical and optical spectra makes it possible to identify optical 4 f–4 f-transitions between Stark sublevels of multiplets 3P0, 3P1, 3Н5, and 3Н6 in PrYAG. It was shown that an important role in the spectrum of the degree of magnetic circular polarization of luminescence of this paramagnetic garnet is played by the effect of quantum-mechanical J–J mixing of states of Stark singlets 3Н5 and 3Н6 of non-Kramer rare-earth ion Pr3+ in the "green" luminescence band related to forbidden 4 f → 4 f transition 3P0 → 3Н5 in the visible spectral region. To interpret the spectra of magnetic circular polarization of luminescence, the energy of experimentally determined Stark sublevels of multiplets under study, their irreducible representations and wave functions determined by numerical simulation of the energy spectrum of the rare-earth ion Pr3+ in the garnet structure are used. [ABSTRACT FROM AUTHOR]

Pro- and anti-inflammatory cytokines modulate the inflammatory response in the gastric mucosa. The analysis of associations of allelic variants of cytokine genes in the process of tumorous transformation of the gastric mucosa is an urgent problem. Its solution could make it possible to identify the features of production of inflammatory mediators by the immunocompetent cells during gastric carcinogenesis. The frequencies of alleles and genotypes of the rs1143634 and rs16944 loci of the IL1β gene, rs71941886 of the IL1RN gene, rs4073 of the IL8 gene, and rs1800872 of the IL10 gene were analyzed in 221 patients with established diagnosis of gastric cancer, as well as in 279 unrelated healthy individuals from the Republic of Bashkortostan. We discovered an association of the allele С and genotype C/C of the rs1143634 locus of the IL1β gene with a risk of development of malignant tumors of the stomach in men. We identified statistically significant differences in between patients and the control group in the distribution of frequencies of alleles and genotypes of the polymorphic variants: rs16944 of the IL1β gene and rs1800872 of the IL10 gene. Dependence of the associations with clinical features of the disease was also shown. Application of the APSampler algorithm revealed the combinations of alleles and genotypes associated with reduced and increased risk of the development of gastric cancer. The most significant were IL1β (rs1143634)*T + IL1β (rs16944)*T/T, IL8*A + IL10*A + IL1β (rs1143634)*T + IL1β (rs16944)*T, and IL10*A + IL1RN*2/2. The obtained results confirm the influence of the investigated allelic variants of cytokine genes on the risk of developing gastric cancer and play an important role in understanding the genetic structure of the studied pathology. [ABSTRACT FROM AUTHOR]

We report chemically synthesized highly crystalline lanthanum strontium manganite (LaSrMnO3) and Eu-doped Y2O3 and their composites. The synthesis yields nanoparticles of size 30–40 nm. Magnetic measurements performed on nanoparticles and composites show magnetic transition at about 370 K with a superparamagnetic behavior at room temperature. The ferromagnetic resonance studies of the nanoparticles show large linewidth due to surface strains. The composite nanoparticles also display luminescent behavior when irradiated with ultraviolet light. The manganites as well their composite with the luminescent nanoparticles may be very useful for biomedical applications. [ABSTRACT FROM AUTHOR]

The paper presents the results of a long-term (52 months) monitoring of molecular hydrogen release from the rocks of the Lovozero Massif. Observations are performed in an underground mine with the help of a portable highly sensitive gas analyzer developed at the National Research Nuclear University MEPhI. The strong variability (of 0.7 to 303 ppm) of the dynamics of the volume concentration of hydrogen (φH2) is established. The main elements of the structure of the time series obtained consist of the fact that they have quite sustained and long intervals of low background concentrations, low-amplitude excesses of various durations, and short (usually high-amplitude) bursts. Seasonal and off-season periodic and other cyclic components in the structure of the series are identified. It is shown that the most important factors determining the dynamics of φH2 are barogenic (variation in the atmospheric pressure) and technogenic (technological explosions). Possible mechanisms of gas release are considered. [ABSTRACT FROM AUTHOR]

We report the growth and magnetic characterizations of La0.7Ba0.3MnO3 and La0.7Sr0.3MnO3 films on SrTiO3-buffered Si (100) and Si (111) substrates by pulsed-laser deposition. The structural studies show the epitaxial nature of the films. The microscopic studies show that the films consist of nanocrystalline particles. All films display sharp magnetic and electrical transitions associated with the colossal magnetoresistance behavior at and above room temperature, illustrating the superior quality of the films. [ABSTRACT FROM AUTHOR]

We report on ferromagnetic properties of ZnMnO and Co:TiO2 films grown by pulsed laser deposition with varying growth conditions. We have demonstrated that ZnMnO films show ferromagnetic properties at room temperature. However, oxygen plays a dominant role in the occurrence of ferromagnetism. Introducing carriers into ZnMnO films did not improve the ferromagnetic properties. Our experimental results indicate that the mechanism for ferromagnetism lies, probably, within the perspective of charge transfer between Mn ions through oxygen. On the other hand, our experimental results suggest that the ferromagnetism in Co:TiO2 films is controlled by the presence of small metal Co2+ clusters in the rutile TiO2 matrix, which are mainly present at the interface and on the surface of the films. [ABSTRACT FROM AUTHOR]

We report on the ferromagnetic resonance studies on ZnMnO films grown by the pulsed-laser deposition technique. ZnMnO films were annealed in different atmospheres. The films grown and annealed in oxygen demonstrate ferromagnetic behavior at room temperature and below. However, annealing in either nitrogen or argon deteriorates the ferromagnetic response of the films. Further annealing the films in oxygen recovers the ferromagnetic response. Our results suggest that oxygen plays a major role for controlling the ferromagnetic properties in ZnMnO films. [ABSTRACT FROM AUTHOR]