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The branching ratios of the four-lepton decays and are found on the basis of the Standard Model, and the respective single-differential distributions are obtained and analyzed within this framework. The contributions of virtual-photon emission by the and quarks of the meson and virtual-photon bremsstrahlung by a final-state charged lepton are taken into account in the calculations. Virtual-photon emission by the quark is described on the basis of the vector-meson-dominance model. [ABSTRACT FROM AUTHOR]

The grazing X-ray diffraction study of phase-II NbS3 whiskers with charge density waves has shown that they exhibit pairs of broadened reflections from two close phases with the monoclinic angles β1 and β2 instead of single peaks. The phase with the smaller monoclinic angle β1 = 95.9°–97.2° is close in lattice parameters to phase I without charge density waves. Phase II with β2 = 99.9°–100.0° has a reduced b lattice parameter along the strongest bond, which implies an increased concentration of sulfur vacancies in this phase compared to phase I. It has been concluded that the studied whiskers have underwent a spinodal decomposition with the redistribution of sulfur vacancies resulting in the alternation of phases in the (001) direction perpendicular to the layers. A satellite structure indicating the formation of a superlattice with a period of 35.2 nm in this direction is observed in the most structurally perfect whisker of phase II. The spinodal decomposition is combined with high internal stresses present in whiskers with a monoclinic lattice. The partial spinodal decomposition is also observed in some phase-I whiskers without charge density waves with the appearance of thin layers of phase IV and phase II with the monoclinic angle β = 104°. The existence of thin layers of phase II in the bulk of phase I in such samples exposed to a high-frequency voltage has been confirmed by the presence of Shapiro steps on current–voltage characteristics. Spinodal decomposition should be taken into account to describe the properties of NbS3 whiskers nominally belonging to a certain polytype. [ABSTRACT FROM AUTHOR]

The classicality concept is formulated. It is used to derive Wigner inequalities dependent on three instants. The possibility of testing experimentally violations of these inequalities in pure and mixed flavor states of a pair of neutral pseudoscalar mesons is studied. Within the Werner background model, it is shown that a violation of time-dependent Wigner inequalities may be observed even at a 50 fraction of background processes. [ABSTRACT FROM AUTHOR]

Partial widths and double- and single-differential distributions are calculated on the framework of the Standard Model for the four-lepton decays , where = and . The contribution of virtual-photon emission by a light quark and a heavy quark, the bremsstrahlung contribution from charged leptons in the final state, the weak-annihilation contribution, and the contribution of wide vector resonances are taken into account. The contribution of narrow and resonances is excluded. Virtual-photon emission by the light quark of a meson is described on the framework of the vector-meson-dominance model, within which only the contributions of the lightest vector mesons containing pairs are taken into account. For the meson, this is the resonance. For the meson, the contributions of the and resonances are taken into account. Two possibilities are considered in the present study. The first is that where the contributions of the narrow and mesons are excluded from the partial widths with respect to the corresponding decays. The second is that where the contributions of narrow resonances are taken into account in partial widths. The problem of the influence of the subtraction procedure on the partial widths with respect to the decays is studied individually. [ABSTRACT FROM AUTHOR]

The prospects are substantiated of using the air data system with one fixed flush-mounted receiver, built-in sensors of incoming flow parameters, and calculator on ultralight and small aircraft. Based on the previously developed analytical models for determining the output signals of this promising system, the study of the instrumental and methodic errors of its measurement channels was carried out. Analytical models are obtained for the instrumental and methodic errors of measurement channels of the air data system with one fixed flush-mounted receiver of incoming air flow parameters. [ABSTRACT FROM AUTHOR]

Application of optical coherence tomography (OCT) in neurosurgery mostly includes the discrimination between intact and malignant tissues aimed at the detection of brain tumor margins. For particular tissue types, the existing approaches demonstrate low performance, which stimulates the further research for their improvement. The analysis of speckle patterns of brain OCT images is proposed to be taken into account for the discrimination between human brain glioma tissue and intact cortex and white matter. The speckle properties provide additional information of tissue structure, which could help to increase the efficiency of tissue differentiation. The wavelet analysis of OCT speckle patterns was applied to extract the power of local brightness fluctuations in speckle and its standard deviation. The speckle properties are analysed together with attenuation ones using a set of ex vivo brain tissue samples, including glioma of different grades. Various combinations of these features are considered to perform linear discriminant analysis for tissue differentiation. The results reveal that it is reasonable to include the local brightness fluctuations at first two wavelet decomposition levels in the analysis of OCT brain images aimed at neurosurgical diagnosis. [ABSTRACT FROM AUTHOR]

New derivatives of 2-methoxy-1-tetrazolylmethyldiazene 1-oxides bearing additional explosophoric groups were synthesized. The reactions of the appropriate aminotetrazoles with trinitromethane in the presence of paraformaldehyde gave trinitroethylamine derivatives and nitration of these aminotetrazoles with dinitrogen pentoxide led to nitramines. [ABSTRACT FROM AUTHOR]

Using the Lévy process (solution of the Ito–Skorokhod stochastic differential equation), we propose the structure of the model of a threshold process and an approximate maximum likelihood method based on the approximation of the logarithmic function of the likelihood of observations. We find the estimates for the parameters of the two-mode threshold jump process with discretely sampled data and show that it is possible to determine the presence of threshold effects by checking the likelihood ratio. [ABSTRACT FROM AUTHOR]

In this paper, the issues on current optimization methods for identifying modern digital camera photosensors are presented. Methods for improving the reliability of identification of digital cameras are discussed, i.e., determining the digital camera used to take a particular photograph. Homogeneous images were optically recorded to form a noise signature, and sets of amateur images were tested for identification of three types of cameras from the images. Digital image filtering and image identity metric were optimized. An optimal digital filter was selected to evaluate smoothed images to obtain the noise signatures of the identified cameras. An optimal identity criterion was obtained by comparison of camera noise signatures. Using an optimal filter and identity criterion allowed increasing, on average, the reliability of identifying the camera used to take a particular photograph by > 60 times. This work provides reference to solve image problems in image registration and processing, security, forensics, and big data analysis. [ABSTRACT FROM AUTHOR]

Recent results on the synchronization of the sliding of charge density waves with a radio-frequency electric field, which is manifested in the appearance of Shapiro steps on current–voltage characteristics have been reviewed. Oscillations of the widths of Shapiro steps depending on the amplitude of the radio-frequency field have been studied experimentally and the periodicity of oscillations in the displacement of a charge density wave in the half-cycle of the radio-frequency field has been demonstrated. It has been shown that the width of Shapiro steps can be related to the position of the return point of the charge density wave with respect to the periodic pinning potential. It has been demonstrated how the proposed approach allows one to obtain the form of a current–voltage characteristic measured under the application of the radio-frequency field and to describe Shapiro steps at the frequency mixing on the charge density wave. An original experiment has been described to determine the amplitude of oscillations of the charge density wave in the periodic pinning potential using a radio-frequency lock-in detector. The comparison of the experimental result with the calculation has revealed the effect of the periodic pinning potential on the amplitude of oscillations in the synchronization regime when the action of the periodic pinning potential is not averaged. The synchronization of the charge density wave in high electric fields when its sliding can be characterized by a certain mobility has also been considered. An analogy of the found relations with similar relations for a Josephson junction and a si-ngle-channel quantum wire has been demonstrated. [ABSTRACT FROM AUTHOR]

The Ti–Zr placers of the Ergeni Plateau belong to the potential Ergeni placer region in the structure of the Cis-Caucasus placer province. The Ergeni placer region contains the Umantsevo–Malye Derbety, Sadovy–Obilnoe, Balkovskii–Kegulta, Remontnoe, and Buratinskoe placer fields. The vertical section of the Ergeni sediments is subdivided into three parts based on lithological–mineralogical, facies, and structural–textural features. The most productive upper part of the section is composed of fine-to-small-grained sands, which consist of 0.10- to 0.25-mm grains (60–70%) with up to 3–5% of the heavy fraction in some section parts. The analysis of paleomorphological schemes of the eastern part of the Ergeni placer region showed that the areas of occurrence of large linear erosion–tectonic depressions, which are inherited by local redeepened depressions within stable morphostructures, can be considered rather favorable for burial and exposure at the pre-Quaternary stage. The results of study of the mineral spectrum of the heavy fraction of the Sadovy–Obilnoe placer field and its comparison with known Ti–Zr deposits including adjacent territories are provided. The recommendations on the comprehensive use of the Ergeni sands and directions for further studies are proposed. [ABSTRACT FROM AUTHOR]

The effects of radio-frequency electric and strain fields on the depinning and sliding of a charge density wave in the quasi-one-dimensional conductor TaS3 have been compared. The amplitude dependence of the threshold voltage Vt (zeroth Shapiro step) has been studied for both fields. The threshold voltage Vt decreases with increasing radio-frequency electric field Erf at increasing rate |dVt/dErf|, whereas with increasing strain field, the decrease in the threshold voltage Vt is saturated, approaching a constant value. This result indicates a qualitative difference between the mechanisms of influence of the electric and strain fields on the dynamics of the charge density wave and is explained by the modulation of the sliding velocity of the charge density wave and pinning potential in the former and latter cases, respectively. In practice, the result allows one to distinguish the mechanical impact on the dynamics of the charge density wave from the influence of electrical interference at the same frequency. [ABSTRACT FROM AUTHOR]

A technique for approximate solution of the inverse geometric problem of magnetostatics for a plate made of a high-permeability ferromagnet in a magnetic field is presented. The technique is presented both for the case of magnetic transducers located directly above a surface defect of loss of metal continuity and for the case where magnetic transducers are located above the defect-free surface of the plate. It is assumed that the plate is accessible from one side only. The sizes of defects in which the proposed technique works reliably are determined. It is shown that the proposed technique can be used in mobile devices to carry out flaw detection of drill pipes using the MFL (magnetic flux leakage) method directly at drilling sites. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide emissions during production is one of the main trends in modern oil and gas chemistry. One of the most realistic possibilities for achieving this is to involve carbon dioxide generated in technological processes as a feedstock for producing gas chemical products. The maximum effect can be achieved in the production of large-scale chemicals, such as syngas, hydrogen, and methanol. We consider such possibilities and present a new combined autothermal process for the joint production of hydrogen and methanol based on non-catalytic matrix conversion of natural gas into syngas, which allows one to almost avoid CO2 emissions. [ABSTRACT FROM AUTHOR]

Severe course of COVID-19 is largely determined by hyperactivation of the immune system, or cytokine storm, in which immune cells (lymphocytes, monocytes, etc.) play a major role. Using low-voltage scanning electron microscopy, we studied the morphology of lymphocytes and monocytes during cytokine storm. Monocytes and lymphocytes were isolated by fluorescence sorting from the blood of healthy volunteers (n=6) and patients with COVID-19 (n=5) during cytokine storm (IL-6>23 ng/ml, smear positive for SARS-CoV-2). For each patient, 11-32 individual cells were analyzed at magnification of 18-32,000 times. Measurements showed that monocyte size was increased during cytokine storm (p=0.0001). [ABSTRACT FROM AUTHOR]

The paper considers the design features of development and limitations on the use of conventional air data systems based on primary information receivers and sensors distributed over the fuselage. The relevance is substantiated and theoretical foundations are revealed for development of the aircraft air data system with one fixed flush-mounted receiver with built-in primary information sensors and a computing device for processing information and generating output signals. Competitive advantages and scope of application of the system are considered. [ABSTRACT FROM AUTHOR]

The object of the study was the spread of the COVID-19 pandemic in Siberia in 2020–2021. The authors examined this process with a case study of 15 federal subjects. The aim of the study is to explain the mechanism and result (in excess mortality) of penetration of the coronavirus into Siberia, based on the characteristic features of the space of Siberian regions. The novelty of the approach is the use of the most reliable monthly excess mortality statistics for characterizing the demographic impact of the pandemic, involvement of regional normative legal acts with antivirus focus, and application of the theory of spatial diffusion of innovations to describe pandemic waves in the regions of Greater Siberia. The main results of the work are as follows. First, the authors identified five types of Siberian regions in terms of integral demographic damage from the pandemic in 2020–2021: Yamalo-Nenets and Khanty-Mansi autonomous okrugs had the highest excess mortality; Omsk, Novosibirsk, Tyumen oblasts, moderately high mortality; Tomsk oblast and Altai and Krasnoyarsk krais, with relatively high mortality; Irkutsk oblast, the Altai Republic, Kemerovo oblast, the republics of Khakassia and Buryatia, and Zabaykalsky krai, excess mortality below the national average; the Tyva Republic, extremely low excess mortality for the entire pandemic. Second, the authors identified four types of regional spatial systems of Siberia according to the degree of vulnerability to coronavirus diffusion: the most vulnerable open polycentric system; highly vulnerable open centralized system; medium-vulnerable closed centralized system; the least vulnerable closed polycentric system. Third, the authors found that in the first type, the most important for the spread of the pandemic, was relocation spatial diffusion (and its particular characteristic case of rotational migrations); in the second type, relocation diffusion ("airplane") and horizontal diffusion (in the contour of the local labor market); in the third and fourth types, horizontal spatial diffusion. The common factors of industry specialization, population density, and transport infrastructure in the conditions of Siberia had little effect on the level of coronavirus incidence. Much more important was the communication (contact-intensive) context of these factors, which determined the potential for infection and the pandemic spreading rate in the space of Siberian regions. [ABSTRACT FROM AUTHOR]

The paper reports the results of a kinetic and thermodynamic analysis of non-catalytic partial oxidation of methane and C2–C4 hydrocarbon/hydrogen mixtures (C/H = 1 : 4) at 1400–1700 K. The hydrocarbon conversion sequence and the time periods of the major process stages were identified for isothermal conditions. The initial stage of the oxidative conversion of C2+ hydrocarbons consists of their pyrolysis, primarily into ethylene and propylene, followed by oxidation of the pyrolysis products. In this respect, the kinetics of C2+ hydrocarbon oxidative conversion are different from those of methane conversion, marked by the almost simultaneous and significantly slower occurrence of pyrolysis and oxidation. The subsequent stages involve steam and dry reforming of the oxidation products, namely acetylene and methane; these stages continue until the main products (H2, CO, CO2, and H2O) reach an equilibrium distribution for the given temperature. The study findings are important for the optimization of various techniques for high-temperature syngas production via partial oxidation of C2+ hydrocarbons, as well as Moderate or Intense Low-Oxygen Dilution (MILD) combustion processes. [ABSTRACT FROM AUTHOR]

The form of the vibrational-rotational operator of kinetic energy for linear symmetric molecules of the A2B2 type in polyspherical nonorthogonal internal coordinates (bond lengths and angles between bonds) is obtained. Nonorthogonal coordinates have advantages in calculating the wave functions of heavy linear molecules, for example, C2F2 and C2Cl2; they also simplify the calculation of the intensity of vibrational-rotational spectral lines of molecules belonging to this type. This work is a continuation of work [1], in which the form of the kinetic energy operator in orthogonal coordinates was obtained. To verify the expressions derived, the lower vibrational-rotational energy levels of the acetylene molecule are calculated. [ABSTRACT FROM AUTHOR]

Terahertz (THz) technology offers a variety of applications in label-free medical diagnosis and therapy, majority of which rely on the effective medium theory that assumes biological tissues to be optically isotropic and homogeneous at the scale posed by the THz wavelengths. Meanwhile, most recent research discovered mesoscale ( ∼ λ ) heterogeneities of tissues; λ is a wavelength. This posed a problem of studying the related scattering and polarization effects of THz-wave–tissue interactions, while there is still a lack of appropriate tools and instruments for such studies. To address this challenge, in this paper, quantitative polarization-sensitive reflection-mode THz solid immersion (SI) microscope is developed, that comprises a silicon hemisphere-based SI lens, metal-wire-grid polarizer and analyzer, a continuous-wave 0.6 THz ( λ = 500 µm) backward-wave oscillator (BWO), and a Golay detector. It makes possible the study of local polarization-dependent THz response of mesoscale tissue elements with the resolution as high as 0.15 λ . It is applied to retrieve the refractive index distributions over the freshly-excised rat brain for the two orthogonal linear polarizations of the THz beam, aimed at uncovering the THz birefringence (structural optical anisotropy) of tissues. The most pronounced birefringence is observed for the Corpus callosum, formed by well-oriented and densely-packed axons bridging the cerebral hemispheres. The observed results are verified by the THz pulsed spectroscopy of the porcine brain, which confirms higher refractive index of the Corpus callosum when the THz beam is polarized along axons. Our findings highlight a potential of the quantitative polarization THz microscopy in biophotonics and medical imaging. [ABSTRACT FROM AUTHOR]

Objectives. To study the relationship between the expression activity of NMDA glutamate receptors and the proliferative activity and genetic properties of anaplastic astrocytomas, as well as the survival of patients with this disease. Materials and methods. This task was addressed by comparing the expression activity of NMDA glutamate receptors – which have been least studied in this context – as detected by immunofluorescence and the polymerase chain reaction, with data from histological and molecular studies, the proliferative activity of neoplasms, and patient survival. Results. The expression activity of NMDA glutamate receptors was found to be higher in grade 3 astrocytomas not carrying mutations in the IDH1 and IDH2 genes. NMDA receptor expression activity was also found to correlate directly with proliferative activity in tumors. NMDA receptor expression activity had a significant impact on the prognosis of relapse-free survival in patients. Conclusions. This work provides the first demonstration that NMDA glutamate receptors have a significant role in the progression of diffuse astrocytomas, which can become the basis for the creation of new approaches to treatment and diagnosis. [ABSTRACT FROM AUTHOR]

The advantages and prospects are considered of using an electronic system for spatial measurement of air motion parameters having a fixed incoming flow receiver and ultrasonic instrumentation channels with frequency primary informative signals and a built-in computer on various aviation equipment and small-sized aircraft. Analytical models were developed, the calculation and analysis of instrumental and methodic errors of the instrumentation channels of the electronic system under consideration was carried out. [ABSTRACT FROM AUTHOR]

The authors construct limit generators for the system of stochastic differential equations with semi-Markov switching and diffusion perturbance under the conditions of the existence of a single equilibrium point of the performance criterion. They assume the existence of a single control on each interval and solve a two-level problem. The authors also examine how the behavior of the limit process depends on the pre-limit normalization of the stochastic system in the ergodic semi-Markov environment. [ABSTRACT FROM AUTHOR]

Synthesis of halomethyl derivatives of 2-methoxydiazene 1-oxides was developed. It was shown that alkylation of tetrazole salts with bromomethyl and iodomethyl derivatives gave the mixtures of two isomers at the positions 1 and 2 of the tetrazole ring. Alkylation of 5-nitrotetrazole selectively afforded the isomer at the N(2) position of the tetrazole ring. [ABSTRACT FROM AUTHOR]

Studies of the COVID-19 pandemic have repeatedly demonstrated that the role of spatial factors in the transmission of infection is significant. However, there is no universal spatial model thoroughly describing COVID-19 spread patterns. The paper proposes an original view on the centre-periphery model: regions are classified according to settlement pattern (static component) and openness (closedness) (dynamic component) characterising intensity of inter-regional human interactions (population flows). A total of 8 types of Russian regions are distinguished by the parameters of openness (closedness), population density and average size of a settlement. The course of the pandemic in the regions is analysed using the monthly trend of excess mortality, divided into three waves (acute phases) of COVID-19 spread. Empirical evidence shows that regions differ significantly in terms of the impact of the pandemic. Polarisation is the highest in the first wave, suggesting a greater role for spatial factors in the early stages of coronavirus outbreak. During the second and third waves, differences between regions begin to level out, probably influenced by internal socio-cultural and economic factors. The COVID-19 pandemic in the Russian regions allows us to rethink the traditional hierarchical concept of centre-periphery space. New dimensions are emerging: in addition to classical centres, there are remote frontier regions with similar functionality. Alongside the periphery is the outback (glubinka), close to the centre but paradoxically almost unaffected by its influence. [ABSTRACT FROM AUTHOR]

In this paper we discuss the possibility of classicality experimental verification at -factories. We show that for three moments of time it is possible to observe violations of Wigner's inequalities, even with the 50% fraction of background processes. [ABSTRACT FROM AUTHOR]

As part of the Standard Model (SM), we present new theoretical predictions for the branching ratio and differential distributions for the decay. We take into consideration the contributions and of resonances; the main contributions of four charmonium resonances: , , , and ; the contributions of the tails from and resonances; and the nonresonant contribution of the pairs, bremsstrahlung, and the contribution of the weak annihilation. We use the model of vector meson dominance (VMD) for calculating resonances contributions. [ABSTRACT FROM AUTHOR]

Pulsating turbulent flows in a square pipe are studied numerically. The flow dominance regime in which the fluid flow rate remains positive in all phases of the oscillatory cycle is considered. The flows are studied at several oscillation frequencies. The results are compared with oscillating laminar flows and a steady turbulent flow in a square pipe, as well as with pulsating turbulent flows in a round pipe. The integral and fluctuating characteristics of turbulence and their dependence on the oscillation frequency are determined. In particular, it is found that at the considered Reynolds number Re = 2200 the friction coefficient in pulsating flows turns out to be lower than that in the stationary flows. The drag reduction increases with growth of the oscillation period and reaches 14.7%. A distinctive feature of turbulent flows in pipes of rectangular cross-section is the occurrence of secondary flows of Prandtl's 2nd kind. The details of secondary flows under the pulsating flow conditions are studied at length. [ABSTRACT FROM AUTHOR]

Experimental apparatus for determining the power characteristics of pneumatic membrane actuators with different design parameters is described. An empirical formula is derived for the working force developed by the pneumatic chamber in the initial stages. [ABSTRACT FROM AUTHOR]

Within the balanced approximation of fiber lasers (FLs) considered as distributed systems, an improved mathematical model is constructed that describes the low-frequency dynamics of FLs with mirrors based on optomechanical micro-oscillators (MOs), taking into account the effect of spontaneous emission (SE) localized in the cladding modes of the active fiber (AF). The mechanisms of the effect of SE on the synchronous self-oscillations (SSOs) in the FL–MO laser system are revealed: additional inversion removal in the AF due to the finite path length of SE cladding mode photons in the FL active medium, violation of the condition for the internal resonance in the laser system, and perturbation of MO oscillations by photoinduced force caused by SE. By means of numerical simulation of SSOs in an erbium–ytterbium FL with an MO and experimental studies, the dependence of the SSO frequency on the geometric-optical parameters of the AF and the reflectivity of the AF–environment interface has been established, which can be used to improve the frequency stability of laser pulses in fiber sources of pulsed radiation and create a new class of resonant fiber-optic sensors. [ABSTRACT FROM AUTHOR]

The importance of reliable information is substantiated in terms of aerodynamic angles and air speed for piloting, control, and ensuring the flight safety of airplanes and other types of aerial vehicles in the surface layer of the atmosphere. Analytical models are developed and results of calculating the methodological aerodynamic errors of measuring the true air speed, indicated speed, Mach number, and aerodynamic angles of attack and slip for the panoramic sensor of the air speed vector parameters, are presented. The ways are considered of reducing the systematic and random components of aerodynamic methodological errors by introducing the corrections to calculation algorithms, implementing the principles of interconnecting and optimal filtration. [ABSTRACT FROM AUTHOR]

A detailed description of a technique is presented that allows one to solve the inverse geometric problem of magnetostatics for surface defects of a ferromagnetic plate in the three-dimensional case with any configuration of the relative position of magnetic transducers and defects and taking into account the nonlinearity of the response of the ferromagnet to an external stationary magnetic field. The application of the technique to a configuration in which defects are located on the metal surface closest to the magnetic transducers is given for the first time. [ABSTRACT FROM AUTHOR]

An experimental setup has been created that allows measuring the values of magnetic field components above the surface of a metal plate in automatic mode. The experimental setup takes the readings of magnetic Hall transducers and sends the processed information to a computer in the form of text and graphic files. Based on experimental data, a component of the measured magnetic field, the shape of surface defects in a plate made of steel 20 was determined using the technique of reconstructing the metal–air boundary along magnetic lines of force. The magnetic transducer, a three-axis digital Hall sensor ALS31300, took measurements over a defect-free metal surface. The nonlinear properties of the ferromagnet are taken into account. [ABSTRACT FROM AUTHOR]

The participation of DNA methylation and histone acetylation in the mechanisms of anterograde amnesia and memory recovery was studied on grape snails trained in conditioned food aversion. Anterograde amnesia developed 10 days after memory reconsolidation impairment with an NMDA glutamate receptor antagonist and was characterized by long-term memory formation impairment upon repeated training. DNA methyltransferase inhibitor injections to snails 1 h before repeated training, as well as 15 min or 4 h after repeated training, caused rapid formation of memory that persisted for at least 10 days. Injections of histone deacetylase inhibitor before repeated training also induced the formation of a stable long-term memory. However, administration of histone deacetylase inhibitor 15 min after repeated training initiated a temporary memory recovery. Injections of the inhibitor 4 h after repeated training were ineffective. These results indicate that histone-dependent chromatin remodeling and DNA methylation are selectively involved in the mechanisms of anterograde amnesia and memory recovery. [ABSTRACT FROM AUTHOR]

Extracellular vesicles play a pivotal role in the intercellular communications influencing various physiological and pathological processes. They carry a range of biomolecular cargoes including small non-coding RNAs (ncRNAs) that could serve as potential diagnostic biomarkers and therapeutic targets. In the current study we applied Next Generation Sequencing to investigate small RNA profiles of erythrocytes, platelets, leukocytes, two plasma fractions and blood cell-derived extracellular vesicles (EVs) (CD41+, CD45+, CD235a+, CD146+) obtained using high-sensitivity fluorescence activated vesicle sorting (hs-FAVS) from plasma of healthy donors. We analyzed the proportions of various small ncRNAs across samples and identified sample specific profiles of microRNA (miRNA) and transport RNA-derived fragments (tRFs). It was found that the cumulative small ncRNA profiles of EVs originated from platelets, erythrocytes, and leukocytes, which are considered to be dominant among the vesicles circulating in blood, differ from small ncRNA profiles of plasma fractions, which represent macrovesicles and exosomes in the circulation. The proportion of miRNAs in sorted EVs was significantly lower compared to other samples while the proportion of tRFs was higher. Moreover, all sorted EVs carried mostly cell type non-specific miRNAs. Taken together, the results demonstrate that the combination of hs-FAVS with small-RNA sequencing technique is a powerful approach to analyze small ncRNA profiles in cell specific vesicles. [ABSTRACT FROM AUTHOR]

The stability and nonlinear interaction between the disturbances in a round jet are investigated numerically at Re = 2850. The conditions of the laboratory experiment performed earlier in the Institute of Mechanics of Moscow State University are reproduced. The characteristic feature of the jet considered is the presence of three points of inflection in the inflow velocity profile. This fact determines essentially the properties of flow. Linear stability is investigated using two approaches: quasi-parallel and spatial. Good quantitative agreement between the results of two approaches and adequate agreement with the results of inviscid theory are obtained. Numerical calculations are carried out with the aim to explain and interpret the results of the laboratory experiment in which change in the length of the laminar-turbulent transition zone in the jet under the action of time-periodic axisymmetric perturbations is revealed. It is shown that axisymmetric disturbances of even considerable initial amplitude do not lead to laminar-turbulent transition. The transition observed experimentally is attributable to the presence of non-controlled three-dimensional disturbances that are strengthened against the background of fairly intense artificial disturbances. The investigations carried out in the present study confirm this hypothesis. Thus, the three-dimensional disturbances serve as an initiator of transition, while the axisymmetric disturbances of a fairly high amplitude only accelerate their growth. It is shown that more intense three-dimensional disturbances are able to ensure still more rapid transition even in the absence of axisymmetric component. [ABSTRACT FROM AUTHOR]

The effect of the welding arc current (47, 57, and 67 A) on the structure and properties of the deposited samples obtained by electric arc robotic deposition has been studied. Welding wire Sv-AK5 (ER4043) of the Al-Si system was used as a filler material. The weld deposition was carried out on a substrate in the form of a plate 6 mm thick made of AMg6 alloy (Al–Mg system). In the process of surfacing, a typical two-phase structure of a hypoeutectic composition is formed in the samples, which is characteristic of alloys of the Al‒Si system with a silicon content of 5%. A trend to the enlargement of the structure in the direction from the substrate is observed along height of the deposited layers, which is associated with the accumulation of heat in the layers deposited along the height. With an increase in the welding arc current, dendrites based on α-Al and eutectic Si crystals are refined, while their density increases and microhardness decreases. The increase in density is due to a decrease in the proportion and size of gas pores and the refinement of structural components. The decrease in microhardness is associated with an increase in the proportion of the soft phase (α-Al dendrites) and a decrease in the number hard eutectic silicon crystals. The average content of silicon in the samples deposited in three modes is in the range of 5.46–5.91%, which corresponds to the chemical composition of the welding wire Sv-AK5 (ER4043). An increase in the welding arc current facilitates a growth of tensile strength and a slight decrease in the conditional yield strength and relative elongation. The patterns of the change in the mechanical properties of the deposited samples are due to the specifics of the formation of the cast structure of the deposited layers under conditions of directional solidification in the direction away from the substrate. [ABSTRACT FROM AUTHOR]

The results of studies on the effect of the charge composition on the structure and mechanical properties of cast aluminum alloys of the Al–Si–Mg (AK9ch) and Al–Mg (AMg6l) systems are presented. It is shown that the contribution of deformed waste in the composition of the charge (electrical waste of aluminum and waste of beverage cans based on alloy 3104—for AK9ch; alloy plates AMg6—for AMg6l) contributes to the formation of dispersed micro- and macrostructure of working alloys in the solid state. The effect of modification (AlSr20 master alloy—for AK9ch; AlTi5 master alloy—for AMg6l) on the structure and mechanical properties of alloys obtained by various charge variants is investigated. Experiments on the effect of the charge composition on the modifiability of AK9ch and AMg6l alloys have shown that the structure of the deformed waste is partially inherited by working alloys through the liquid state. With similar chemical compositions, smaller micro- and macrostructure sizes and increased mechanical properties (tensile strength and elongation under tension) are characteristic of alloys obtained using an increased proportion of deformed waste in the composition of the charge. It was found that, in alloys with an increased proportion of deformed waste, exceeding a certain amount of the modifier element (0.06% Sr for the AK9h alloy; 0.04% Ti for the AMg6l alloy) causes the manifestation of the effect of overmodification. This is expressed in the enlargement of the parameters of the micro- and macrostructure, as well as a decrease in the tensile strength. The results obtained show that the optimal amount of the proportion of deformed waste in the composition of the charge will make it possible in practice to reduce the consumption of expensive modifying ligatures with a guaranteed effect of modification. [ABSTRACT FROM AUTHOR]

The development of noncatalytic procedures for processing hydrocarbon gases is an important way to increase the efficiency of gas-chemical processes and decrease their power consumption. The paper deals with thermodynamic and kinetic modeling of noncatalytic processes of the partial oxidation and steam and carbon dioxide conversion of methane in the temperature interval 1400–1800 K and with analysis of the process for syngas production by matrix conversion of rich methane–oxygen mixtures. Comparison of the kinetic calculations with the experimental data demonstrated the possibility of applying published models to the description of the matrix conversion of methane. The possibility of developing a highly efficient technology based on noncatalytic partial oxidation of hydrocarbons for the syngas production without СО2 emission into the environment is discussed. [ABSTRACT FROM AUTHOR]

The quality of metal powder composition (MPC) made of heat resistant alloy EP648 (Ni–Cr–W–Mo) used for fabrication of parts by direct metal deposition (DMD technology) has been analyzed. It has been established that, regarding the main requirements (chemical composition, particle size distribution, purity, bulk density, yield, moisture content), the MPC meets the requirements of Technical Specifications TU 136-225-2019. The influence of the parameters of direct laser deposition (power of laser radiation, cladding speed) on the structure and microhardness of experimental specimens has been analyzed. The highest number of defects (multiple shrinkage cavities and incomplete fusion) is formed in the specimen fabricated at the power of laser radiation P = 1000 W and the cladding speed v = 40 mm/s. At the same time, the defects have the maximum dimensions. The minimum number of defects is observed in the specimens fabricated at P = 1400 and 1600 W and v = 45 and 38 mm/s. In this case, the most homogeneous structure of laser cladding is formed owing to complete fusion of powder particles and melt spreading. Nevertheless, the structure of the specimen deposited at P = 1600 W and v = 38 mm/s contains cracks located at the subgrain boundaries in the center of cladding tracks. Their formation is caused by overheating of the metal due to higher power of laser radiation and accumulation of high internal stresses after previously deposited layers. The microhardness of the specimens fabricated by all modes of direct laser deposition changes insignificantly in the range of 270–310 HV. On the basis of the obtained experimental results, it has been determined that the most optimum structure is formed in the specimen at the laser power of 1400 W and the cladding speed of 45 mm/s. [ABSTRACT FROM AUTHOR]

The kinetic patterns of the attainment of the equilibrium product composition in non-catalytic processes of partial oxidation and of steam and carbon dioxide reforming of hydrocarbons in the temperature range 1400–1800 K, characteristic of these processes, were analyzed. The need for such analysis is caused by the rapidly increasing consumption of natural gas as a chemical feedstock and by growing attention to environmental problems, in particular, to a decrease in СО2 emissions or to partial CO2 utilization. The forward and reverse water gas shift reactions (WGSRs) play an important role in approach to the equilibrium product composition in these processes. Analysis has shown that the elementary reactions characteristic of forward and reverse WGSRs start to play a significant role long before the equilibrium in the system is attained. Already in the intermediate steps of the process, the distribution of the major reaction products, Н2, СО, Н2О, and СО2, almost corresponds to the equilibrium value of Kt = ([H2][CO2])/([CO][H2O]), close to the WGSR equilibrium constant Keq, and further conversion of the products occurs at Kt values close to Keq. [ABSTRACT FROM AUTHOR]

Impairment of reconsolidation of conditioned food aversion memory led to the development of a specific anterograde amnesia: repeated training of amnestic snails did not induce long-term memory formation. DNA demethylation caused by injections of DNA methyltransferase inhibitor (DNAMT) during repeated training led to long-term memory formation. Injections of an NMDA glutamate receptor antagonist or a serotonin receptor antagonist prevented memory formation induced by administration of DNAMT inhibitor and repeated training. We hypothesize that methylation-dependent repression of neuronal genes underlies anterograde amnesia. Demethylation eliminated the blockade of these genes and created conditions for long-term memory formation, the induction mechanisms of which involve neurotransmitter receptors. [ABSTRACT FROM AUTHOR]

A study on the growing importance of gas chemistry to the world economy and the resulting need to create new catalytic and non-catalytic technologies for converting natural gas and other hydrocarbon gases into chemical products is performed. Existing and promising non-catalytic processes of converting them into synthesis gas are discussed, along with direct ways of obtaining chemical products from methane, the main component of natural gas. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the role of pseudocontinuous arterial spin labeling perfusion (pCASL-perfusion) in preoperative assessment of cerebral glioma grades. The study group consisted of 253 patients, aged 7–78 years with supratentorial gliomas (65 low-grade gliomas (LGG), 188 high-grade gliomas (HGG)). We used 3D pCASL-perfusion for each patient in order to calculate the tumor blood flow (TBF). We obtained maximal tumor blood flow (maxTBF) in small regions of interest (30 ± 10 mm2) and then normalized absolute maximum tumor blood flow (nTBF) to that of the contralateral normal-appearing white matter of the centrum semiovale. MaxTBF and nTBF values significantly differed between HGG and LGG groups (p < 0.001), as well as between patient groups separated by the grades (grade II vs. grade III) (p < 0.001). Moreover, we performed ROC-analysis which demonstrated high sensitivity and specificity in differentiating between HGG and LGG. We found significant differences for maxTBF and nTBF between grade III and IV gliomas, however, ROC-analysis showed low sensitivity and specificity. We did not observe a significant difference in TBF for astrocytomas and oligodendrogliomas. Our study demonstrates that 3D pCASL-perfusion as an effective diagnostic tool for preoperative differentiation of glioma grades. [ABSTRACT FROM AUTHOR]

In conjunction with recognition (sensing) and transport, the signaling properties of nitrate () in species that differ in evolutionary and taxonomic terms, from primitive prokaryotes to flowering plants, are examined. On the basis of a comparative physiological analysis, the authors make assumptions about some pathways of the phylogenetic formation of signaling cascades triggered by the indicated ion. It is possible that nitrate arose on Earth as early as the Catarchea during the anaerobic nature of the primary atmosphere. Then oxygenic photosynthesis appeared, creating the prerequisites for nitrification as the main source of . The increasing gradient of nitrate levels in the medium contributed to the creation of polymorphism of its low- and high-affinity sensors and transporters. The system of sensing and signaling of nitrate from prokaryotes was inherited by eukaryotes and received further development from them. In flowering plants, the formation of new regulatory mechanisms is evident; they determine the possibility of fine tuning sensing and absorption of different doses of with the participation of transporters of appropriate affinity. Depending on the organo-tissue localization of a given ion, the spectrum of its sensors expands, which determines the metabolic direction of the main functions of plants associated with nitrogen assimilation, photosynthesis, and growth and production processes. [ABSTRACT FROM AUTHOR]

The results of a study on the influence of types of welding (laser, electron beam, and argon arc) on the properties of a permanent joint made of an EP693 alloy of the Ni–Cr–W–Co–Mo system used in the production of the components and parts of gas turbine engines (GTEs) are presented. An EP367 filler wire of the Ni–Mo–Cr–Mn system is used to obtain a welded joint during laser and argon arc welding. A comparative analysis of the heating areas, as well as power densities, is performed for the types of welding under study. It is established that argon arc welding is characterized by higher values of the heating area and power density in comparison with laser and electron beam welding. It is found that the type of welding affects the characteristic features of the formation of welding seams (WS's). Thus, in the case of electron beam welding, the WS is formed with the transition to knife fusion penetration in the root of the seam, while in the case of laser welding (LW), the seam is formed in the shape of an hourglass. An analysis of the microstructure of the near-weld zone shows that the smallest grain size is observed in the case of LW. The distribution of the elements in the welded joint is analyzed. It is established that the concentration of Mo increases and the concentrations of W, Co, Al, and Ti decrease in the WS and near-weld zone relative to the base material (BM) in the case of welding with the use of a filler wire. This determines the peculiarities of the destruction of samples obtained by the types of welding under consideration. The destruction of the samples obtained by argon arc and LW occurs along the near-weld zone from the side of seam reinforcement, while the samples obtained by electron beam welding undergo destruction along the WS. Mechanical tests of the samples at room and elevated temperatures show that the samples obtained by laser and electron beam welding have the highest tensile strength. [ABSTRACT FROM AUTHOR]

A simple and convenient form of the vibrational-rotational kinetic energy operator for symmetric molecules of the A2B2 type in polyspherical orthogonal coordinates is suggested. Features of the approach suggested are the symmetry of the kinetic energy operator with respect to the permutation of the coordinates of two groups of atoms (AB) and the ease of applying the wave function contraction. A variational calculation of the lower vibrational-rotational energy levels of the acetylene molecule has been made. The energy levels calculated in this work are compared with other sources. [ABSTRACT FROM AUTHOR]

A method resistant to input data errors for determining the depth and opening of a two-dimensional surface defect in a ferromagnet is presented. Defects and magnetic transducers are located on opposite sides of a metal plate. The nonlinear properties of the ferromagnet are taken into account. The components of the magnetic field in the metal were reconstructed from the measured components of the magnetic field above the defect-free surface of the metal. The limits of applicability of the method are obtained as a result of numerical experiments. The results of the technique have been verified experimentally. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is a zoonotic parasite with a wide host range that includes humans, domestic animals and wild animals. Small mammals serve as intermediate hosts for T. gondii and may contribute to the persistence of this parasite in the environment. Mass mortality in wild animals and deaths in rare endemic species make the study of this parasite of growing importance. In this study, T. gondii infection prevalence was evaluated in brain tissues from 474 small mammals captured at 26 trapping points in urban and rural areas of Tatarstan, Russian Federation. Nested PCR was used to detect the T. gondii B1 gene in the samples. Overall, 40/474 samples (8.44%) showed B1 gene positivity. T. gondii infection among the wild small mammals trapped in the rural area was significantly higher as a whole than that of the urban area as a whole. Multivariate logistical regression analysis also showed that the trapping area (rural or urban) significantly contributed to T. gondii positivity. Vegetation in the trapping points, small mammal species, sex, age or distance from the trapping points to the nearest human settlements did not significantly affect T. gondii positivity in the sampled small mammals. [ABSTRACT FROM AUTHOR]

The results of magneto-thermal surface reinforcement of polymeric materials are presented on the example of plates made of high-density polyethylene and polypropylene. As part of the experiments, iron powder with an average particle size of 60 μm was applied to the plate samples under the influence of magnetic and thermal fields. An increase in the mass of samples was established (on average by 15–20% of the mass of the original sample) and the basic dependencies between the main parameters of the magneto-thermal reinforcement process were determined. [ABSTRACT FROM AUTHOR]