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Kuznetsov's formula relates the parameters of erosion resistance and soil water stability. However, the mechanism of occurrence of these properties is different: water stability is explained by the action of intra-aggregate hydrophobic bonds in organomineral soil gels, and erosion resistance is explained by water stable aggregates and their adhesion to each other. There is a contradiction in the proposed mechanisms of two similar phenomena. The purpose of the work was to clarify the mechanism of erosion resistance of soils and compare it with the mechanism of formation of water stability. The work used samples of humus-accumulative soil horizons: sod-podzolic and leached chernozem. To obtain samples with the same aggregate composition, but differing in erosion resistance, it is proposed to use soil polymer ameliorants (SPMs). The erosion resistance of soils was determined on a hydrolotter and the critical rate of flushing was calculated. The water stability of the soils was assessed by the blade method. The particle size in the solutions was estimated by laser diffractometry. It was found that, on soils treated with SPMs, the results of the tray and blade methods correlate by 99%. The high correlation suggests a common nature of intra- and interaggregate bonds. To test the role of hydrophobic interactions in the formation of aggregates resistant to water, polymers of varying degrees of hydrophobicity were added to aqueous humate solutions in a model experiment: polyethylene glycol (PEG), polyacrylamide (PAA), and polyvinyl alcohol (PVA). In parallel, the water stability of soils treated with PEG, PAA, and PVA was evaluated. Analysis of the results showed that the greatest water stability of the aggregates was noted when the most hydrophobic polymer, polyvinyl alcohol, was added to the soil, which formed the largest particles when interacting with humate in the model experiment. These results confirm the role of hydrophobic interactions in the formation of aggregates and indicate that when selecting polymer structures, their interaction should be taken into account not with clay minerals, but with soil gels, which include clay minerals and humic substances. [ABSTRACT FROM AUTHOR]

Clarithromycin (CLR) is currently a key antibiotic for Helicobacter pylori infection treatment, however, the data on CLR resistance patterns in Russia are missing. Here, we applied WGS-based approach to H. pylori clinical isolates from Russia to comprehensively investigate sequence variation, identify putative markers of CLR resistance and correlate them with phenotypic susceptibility testing. The phenotypic susceptibility of 44 H. pylori isolates (2014–2022) to CLR was determined by disc diffusion method: 23 isolates were CLR-resistant and 21-CLR-susceptible. All isolates were subjected to WGS and submitted to GenBank. Based on complete sequence analysis, we showed that among all sequence variants, the combination of mutations A2146G/A2147G in the 23S rRNA gene is the most reliable for prediction of phenotypic susceptibility. For the first time, the average number of mutations in 106 virulence-associated genes between resistant and susceptible groups were compared. Moreover, this study presents the first WGS insight into genetic diversity of H. pylori in Russia with a particular focus on the molecular basis of drug resistance: the novel mutations were described as potential markers for the resistance development. Of these, the most prominent was a frameshift deletion (252:CGGGT) in HP0820 coding region, which is a good candidate for further investigation. [ABSTRACT FROM AUTHOR]

The local ordering and features of the molecular mobility of water confined in voids of a pure silica mordenite were studied using the molecular dynamics simulation over a temperature range from 298 to 163 K. The simulated system was a fragment of mordenite consisted of 2 × 2 × 4 unit cells filled with 384 water molecules. Three different water models: SPCE, SPCF, and TIP5P were considered. To study the effect of nanoconfinment, the results were compared with bulk water. The modeling suggests that at room temperature, a 2D (in c and b directions of the mordenite cell) water diffusion takes place, while upon cooling, the diffusion in b direction essentially slows down. The analysis of microstructure shows that the pores prevent the formation of a full tetrahedral structure of water environment that results in formation of several water substructures. A detailed analysis of water reorientational motion was carried out and the activation energies were determined from temperature dependences of the correlation times. Of the three water models considered, SPCE demonstrated the best performance. The results obtained can be helpful for interpretation of experimental temperature dependences of NMR relaxation rates for water molecules confined in porous media with complex topology. [ABSTRACT FROM AUTHOR]

The contents of heavy metals (HMs) in the soil and vegetables grown in the Amur region in the period of 2020–2023 were determined by voltammetry. The zinc, cadmium, lead, and copper contents in the soil do not exceed the background and approximately permissible concentrations. According to the total accumulated amount in vegetable produce, the heavy metals are arranged in the following order: Cu > Pb > Zn > Cd. [ABSTRACT FROM AUTHOR]

Malnutrition is a frequently underdiagnosed condition leading to increased morbidity, mortality, and healthcare costs. The Mount Sinai Health System (MSHS) deployed a machine learning model (MUST-Plus) to detect malnutrition upon hospital admission. However, in diverse patient groups, a poorly calibrated model may lead to misdiagnosis, exacerbating health care disparities. We explored the model's calibration across different variables and methods to improve calibration. Data from adult patients admitted to five MSHS hospitals from January 1, 2021 - December 31, 2022, were analyzed. We compared MUST-Plus prediction to the registered dietitian's formal assessment. Hierarchical calibration was assessed and compared between the recalibration sample (N = 49,562) of patients admitted between January 1, 2021 - December 31, 2022, and the hold-out sample (N = 17,278) of patients admitted between January 1, 2023 - September 30, 2023. Statistical differences in calibration metrics were tested using bootstrapping with replacement. Before recalibration, the overall model calibration intercept was −1.17 (95% CI: −1.20, −1.14), slope was 1.37 (95% CI: 1.34, 1.40), and Brier score was 0.26 (95% CI: 0.25, 0.26). Both weak and moderate measures of calibration were significantly different between White and Black patients and between male and female patients. Logistic recalibration significantly improved calibration of the model across race and gender in the hold-out sample. The original MUST-Plus model showed significant differences in calibration between White vs. Black patients. It also overestimated malnutrition in females compared to males. Logistic recalibration effectively reduced miscalibration across all patient subgroups. Continual monitoring and timely recalibration can improve model accuracy. [ABSTRACT FROM AUTHOR]

The structure and mechanical properties of rolled sheets with a thickness of 40 mm made of low-carbon low-alloyed steel after thermomechanical treatment of different modes are investigated. The structural factors that affect obtaining high mechanical properties are established. It is shown that a complex treatment including quenching from the rolling temperature and high-temperature tempering with a subsequent additional cycle of quenching and tempering leads to formation of rolled sheet uniform over the cross section with a fragmented bainite structure with disperse niobium carbides and carbides of cementite type. Such structure provides a yield strength of no less than 630 MPa in combination with high values of the impact energy at negative temperatures and a level of plasticity of δ ≈ 20%. [ABSTRACT FROM AUTHOR]

Every fourth person in the world currently has kidney problems to one or another degree. It is known that the novel coronavirus infection (COVID-19) is primarily a respiratory disease, but the kidney is a target organ. The coronavirus is tropic to kidney tissue due to the presence in the organ of RNA of angiotensin-converting enzyme type 2 and transmembrane serine protease 2, which is considered to be a target of this virus. The presence of renal failure in any stage is an independent unfavorable risk factor for contracting coronavirus and leads to a high frequency of hospitalization and mortality rate. Kidney failure is caused by various pathogenetic mechanisms: the direct cytopathic effect of the virus on their structures (podocytes, mesangial cells in the renal corpuscle, capillary endothelium in the glomerulus, epithelial cells in the proximal tubules), cytokine storm, damage to the renin–angiotensin–aldosterone system, and immunothrombosis. In many patients with confirmed coronavirus infection, from the first days of the disease, laboratory tests show significant changes in urine analysis (hematuria, proteinuria) and increased level of creatinine in the blood serum. The development of acute kidney injury is a main mortality risk factor. More research is needed into the exact effects of SARS-CoV-2 on the kidneys. Understanding the main pathogenetic pathways of their damage in COVID-19 is necessary to develop strategies and effective treatments. [ABSTRACT FROM AUTHOR]

Regularities in the joint influence of the chemical composition and parameters of the globular-lamellar structure of VT6 alloy on the mechanical properties of rolled bars on its basis after annealing in various modes are studied. The conducted correlation analysis found that fluctuations in the grade composition of samples in terms of aluminum and molybdenum equivalent values have a more significant effect on their mechanical properties than the structural factor. A model for forecasting the ultimate strength of annealed bars with a diameter of 15–90 mm is developed, taking the chemical composition and parameters of the globular-lamellar structure into account. [ABSTRACT FROM AUTHOR]

Regulation of mitochondrial functions impacts on neuronal differentiation and maturation. Studying these processes is of both fundamental and practical importance for regenerative neurobiology. This work was aimed to characterize the changes in mitochondrial fission and their link with the activation of oxidative phosphorylation (metabolic switch) during the maturation of human induced pluripotent stem cell (iPSC)-derived neural progenitors xenografted in the rat striatum. Wistar rats (n = 15) were unilaterally injected into the caudate nucleus with neural precursors derived from the human iPSCs. Changes in the localization and expression of neuronal differentiation markers, such as nestin, NeuN, neuron-specific enolase, mitochondrial outer membrane protein, ATP synthase, and mitochondrial fission protein Drp1, were assessed by immunostaining. Measurements of grafted cells were performed 2 weeks, 3 and 6 months after surgery. The maturation of grafted neurons was associated with fluctuations in morphometric parameters of the mitochondrial fraction and Drp1 levels. An increase in mitochondrial fission was detected 3 months after grafting, preceded by an increase in ATP synthase level by month 6 and switching grafted neurons to oxidative phosphorylation. The experiment revealed a link between mitochondrial dynamics and changes in the metabolic profile and maturation of grafted neurons. The regulation of mitochondrial dynamics may have future implications for developing methods to improve the integration of grafted neurons into recipient brain structures. [ABSTRACT FROM AUTHOR]

This review summarizes advances in the synthesis of 1,3,4-oxadiazoles, 1,2,4-isoxadiazoles, thiadiazoles and triazoles based on compounds containing at least one sp-hybridized carbon atom. Unlike existing reviews reporting classical methods for the synthesis of these compounds, this work combines new approaches aimed at the use of highly reactive compounds. The main trends, their development, and achievements in this field of synthesis of these classes of heterocyclic compounds, advantages and limitations of the approaches used for 1961–2023 are presented. [ABSTRACT FROM AUTHOR]

The paper is focused on mathematical modeling of heat transfer in an anisotropic plate with heat energy drain due to various physical and chemical transformations inside the material and under conditions of exponential heat transfer at the boundary. The analytical solution of the second initial boundary value problem of heat conduction with nonlinear heat energy flow is obtained and investigated. [ABSTRACT FROM AUTHOR]

In this paper, an economical unconditionally stable method of variable directions with extrapolation of numerical solutions of problems for parabolic equations containing mixed derivatives is proposed and justified by approximation and stability, which, in comparative analysis with other numerical methods, showed the highest accuracy and a unique margin of stability when changing grid characteristics. [ABSTRACT FROM AUTHOR]

The simultaneous transformation of both components of the complex isotropic vibrational susceptibility, which occurs with an increase in the density of a gas consisting of linear molecules, is traced for the first time in terms of the quantum model of strong collisions. The vibrational susceptibility of the CO2 molecule in the region of the fundamental ν3 band is discussed in detail as a case in point. It is found that within the region of anomalous dispersion adjacent to frequency ν3, there is a spectral interval that is characterized by positive dispersion and exists in a fairly wide pressure range. This interval narrows upon an increase in pressure and disappears at a density of around 100 Amagat, completely blurring the branch structure of the absorption band. It is shown that allowing for the spectral exchange between the lines of the rotational structure of the band is equally important for quantitatively interpreting the spectrum of the real part of susceptibility and reproducing a correct picture of the transformation of the absorption spectrum. [ABSTRACT FROM AUTHOR]

Results are presented from optical profilometry and scanning probe microscopy studies of the structures and surface parameters of germanium single crystals exposed to an alternating magnetic field. A change in the relief and surface roughnesses of the crystals after magnetic field processing and a drop in their optical transmittance in the range of 1.8–23 μm are established. [ABSTRACT FROM AUTHOR]

The reactions of acetylcholine halides with H2O2 were studied at room temperature in initially deionized water, i.e., at pH ∼7. Acetylcholine (ACh), which catalyzes the decomposition of hydroperoxides and H2O2 into radicals in an organic medium, virtually does not affect the decomposition of H2O2 in aqueous solutions. In the case of AChI, hydrogen peroxide oxidizes the iodide anion to form diiodine and hydroxyl radical HO•, which was identified using the 5,5-dimethylpyrrolidine N-oxide spin trap. The rate constant of this reaction was estimated from the initial sections of the kinetic curves for the consumption of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPOL): k1 = (2.0±0.1)•10−3 L mol−1 s−1. A nontrivial combination of radical reactions and redox disproportionation reactions occurs in the AChI—H2O2—TEMPOL system in initially deionized water. In this medium, H2O2, iodine compounds, TEMPOL, and the formed hydroperoxide radicals HO2• have a dual ability to act as oxidants or reducing agents, which results in quasi-stationary concentrations of I2 and TEMPOL being established in the process. The I− oxidation by peroxides in acid medium, known in iodometric titration, generates hydroxide radicals when conducted in neutral solutions (pH ∼7) and can compete with the Fenton reaction in systems in which the presence of metal ions is excluded. [ABSTRACT FROM AUTHOR]

The conditions were developed and the optimal temperature regime was selected for a selective thionation of 5-aryl-3-[(dimethylamino)-methylidene]furan-2(3H)-ones with Lawesson's reagent. The stereochemistry of the synthesized 3-[(dimethylamino)methylidene]furan-2(3H)-thiones was established. Based on this, a number of 3-arylaminomethylidenefuran-2(3H)-thiones were synthesized via transamination reaction. [ABSTRACT FROM AUTHOR]

Purpose: The prevalence of parental burnout, a condition that has severe consequences for both parents and children, varies dramatically across countries and is highest in Western countries characterized by high individualism. Method: In this study, we examined the mediators of the relationship between individualism measured at the country level and parental burnout measured at the individual level in 36 countries (16,059 parents). Results: The results revealed three mediating mechanisms, that is, self-discrepancies between socially prescribed and actual parental selves, high agency and self-directed socialization goals, and low parental task sharing, by which individualism leads to an increased risk of burnout among parents. Conclusion: The results confirm that the three mediators under consideration are all involved, and that mediation was higher for self-discrepancies between socially prescribed and actual parental selves, then parental task sharing, and lastly self-directed socialization goals. The results provide some important indications of how to prevent parental burnout at the societal level in Western countries. [ABSTRACT FROM AUTHOR]

Alkylphenols, which are industrial chemicals, are xenoestrogens; however, their sublethal effects on aquatic animals are poorly studied. The aim of this work is to study possible metabolic and reproductive disorders in amphipods using the example of Gmelinoides fasciatus from the Gulf of Finland (Baltic Sea) after experimental exposure to 4-tert-octylphenol (4t-OP) from the group of alkylphenols. The mortality of G. fasciatus amphipods in 4t-OP concentration ranges from 0.5 to 1000 μg/L after 96 h and 7 days increases with increasing concentration. At 4t-OP concentrations of 0.5 and 5 μg/L, the mortality of G. fasciatus has not been observed. At a concentration of 20 μg/L, after 7 days, the mortality of crustaceans is 20%; at a concentration of 100 μg/L, it is 60%. Exposure to sublethal concentrations of 4t-OP (0.5 μg/L) resulted in a decrease in sexual activity of these amphipods after 1 week: only 25% of amphipods retain precopulatory pairs versus 100% in control. Under chronic exposure (28 days) to the lowest concentration, males show signs of demasculinization (a decrease in the width of the gnatopods and an increase in the depth of the coxal plates); females show a decrease in the overall fecundity and irreversible disturbances in the state of embryos (a high proportion (>50%) of embryos stop their development at different stages of organogenesis). The study shows significant functional disorders of metabolic processes and reproduction in crustaceans even when exposed to nonlethal concentrations of octylphenol. These results confirm the high toxicity of this industrial pollutant, the presence of which in the aquatic environment can lead to irreversible changes in the biota. [ABSTRACT FROM AUTHOR]

Seasonal and interannual changes in the Greenland Sea ice age composition during winter months for seven standard age categories are analyzed. To estimate the amount of the ice of different age categories, the digital archive of the region's ice charts for the period 1997–2022 produced by the Arctic and Antarctic Research Institute is used. Statistical insignificance of linear trends has been revealed for the main age categories of the Greenland Sea ice. A comparison of the obtained estimates of the variability in the amount of the ice of different age categories and earlier studies shows that the quantitative changes in the Greenland Sea ice age composition started before 1997. The data on the ice age composition over a 25-year observation period alone are insufficient to draw an unambiguous conclusion about a decrease in the Greenland Sea ice thickness. [ABSTRACT FROM AUTHOR]

We describe approaches to the construction of mathematical models of relaxation processes occurring in industrial-use polymer textile materials. The problem of constructing mathematical models that are most appropriately suited to the processes being modeled is solved. [ABSTRACT FROM AUTHOR]

The authors discuss generative intelligence systems for image synthesis, describes one (DALL E 2) in detail, and provide familiar examples of the use of such systems. The advisability of preparing such a review lies in the current situation in the field of generative intelligence, many inflated expectations and fears, and a practical lack of descriptions and analyses of scenarios for their use in business. This review will be useful to anyone who wishes to understand the real capabilities and limitations of such systems. [ABSTRACT FROM AUTHOR]

This study is dedicated to assessing the friction properties and vibration characteristics of the friction process of a hard alloy based on tungsten carbide with an experimental binder (5.65% Co + 1.8% Mo + 0.6% Ti), created based on the standard VK8 grade by partially replacing cobalt with a Mo+Ti metal group. Tribological tests were carried out without the use of a lubricant according to the "pin-on-disk" scheme during frictional interaction with steels 15Kh2NMFA and 10GN2MFA at constant load and sliding velocity. During the experiments with steel 10GN2MFA, growth of the intermediate layer in the gap between the elements of the friction pair was observed, subsequently resulting in a wider spacing between the friction bodies over time. However, no statistically significant differences were found in the gap thickness and/or roughness of the friction surfaces depending on the hard alloy grade, while the friction coefficient of the experimental composition was lower. Similarly, no significant differences in the friction surface microrelief changes on the counterbodies were found when studying the frictional interaction between samples and steel 15Kh2NMFA. However, the friction dynamics of the experimental hard alloy is characterized by lower friction coefficients and smaller thickness of the intermediate layer, as well as reduced amplitude of vibrations generated by the tribosystem dynamics itself. [ABSTRACT FROM AUTHOR]

The antimicrobial and antioxidant properties of a series of organophosphorous compounds containing the 3,5-di-tert-butyl-4-hydroxybenzyl fragment were studied. As revealed in biological activity assays, the majority of the compounds simultaneously possesses high antibacterial and fungicidal activities against pathogenic and arbitrarily pathogenic human and animal microflora. The influence of the substituents at the phosphonate phosphorus atom and the number of fragments of sterically hindered phenol on the antioxidant capacity of the studied compounds was found. In the case of methoxyl substituents at the phosphonate phosphorus atom, the antioxidant activity decreases sharply compared to the initial antioxidant, ionol (2,6-di-tert-butylphenol), whereas the phenoxyl substituents at the phosphorus atom sharply increase the antioxidant activity of the studied salts. [ABSTRACT FROM AUTHOR]

In this work, by means of bio-strips and cytotoxic potentials of chemical reactions, the decisive impact of solvent choice on the "overall cytotoxicity" of the process is shown by example of 36 routes of 1,1′-biphenyl synthesis. [ABSTRACT FROM AUTHOR]

We performed a comparative assessment of the immunohistochemical distribution of markers of mitochondrial fission (Drp-1), mitochondrial fusion (Mfn-2), and mitochondrial biogenesis (PGC-1α) in pyramidal neurons of different zones of the hippocampus in mice with intrahippocampal administration of β-amyloid peptide 25-35. The most pronounced changes in the dynamics associated with a decrease in the amount of the fission marker and an increase in the amount of the fusion marker were observed in the CA3 field on day 38 after peptide administration. In the CA1 field, a significant decrease in the marker of mitochondrial biogenesis PGC-1α was found on day 38, which can indicate a decrease in the intensity of mitochondrial biogenesis. Early mitochondrial changes can play an important role in the pathogenesis of all types of memory impairment in Alzheimer's disease. [ABSTRACT FROM AUTHOR]

The results of modification of WC–Co samples by a pulsed beam of nitrogen ions (200–300 keV, 120 ns) with an energy density of 7–8 J/cm2 are presented. It is shown that the change in the structure occurs in the near-surface layer with a thickness of 20–30 μm, which significantly exceeds the range of ions in the target (≈0.5 μm) and the depth of propagation of the thermal front during the pulse (≈1 μm). Various mechanisms of the long-range effect, namely, the formation of a shock wave, the generation of primary radiation defects, etc. are analyzed. It is shown that the long-range effect is associated with the charge exchange of ions and the formation of fast atoms. The simulation of the charge exchange of ions in the gaseous layer of desorbed molecules is performed. It is found that the probability of ion charge exchange in the processes N+ + N2 → N0 and N+ + O2 → N0 significantly exceeds 100%, which indicates that the effect of irradiation of the target by fast atoms must be taken into account. In contrast to ions, when the target is irradiated with atoms, the efficiency of the formation of radiation defects is much higher. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 2 (SCA2) is a hereditary disorder, caused by an expansion of polyglutamine in the ataxin-2 protein. Although the mutant protein is expressed throughout all the cell and organ types, the cerebellum is primarily affected. The disease progression is mainly accompanied by a decline in motor functions. However, the disturbances in cognitive abilities and low mental state have also been reported in patients. Recent evidence suggests that the cerebellar functionality expands beyond the motor control. Thus, the cerebellum turned out to be involved into the language, verbal working, and spatial memory; executive functions such as working memory, planning, organizing, and strategy formation; and emotional processing. Here, we used the transgenic SCA2-58Q mice to evaluate their anxiety, cognitive functions, and mood alterations. The expression of the mutant ataxin-2 specifically in the cerebellar Purkinje cells (PCs) in SCA2-58Q mice allowed us to study the direct involvement of the cerebellum into the cognitive and affective control. We determined that SCA2-58Q mice exhibit anxiolytic behavior, decline in spatial memory, and a depressive-like state. Our results support the idea of cerebellar involvement in cognitive control and the handling of emotions. [ABSTRACT FROM AUTHOR]

The study was first carried out on stimulus-specific adaptation of neurons in the primary and anterior fields of the awake house mice auditory cortex to sound sequences of four 100-ms tonal signals, with a frequency of tones corresponding to the neuronal characteristic frequency, and also with the inter-tone interval constant for one sequence and varying from 0 to 2000 ms in different sequences. The analysis of the data obtained showed the adaptation effect in the responses of all studied primary auditory cortex neurons, which was observed as the absence or significant decrease in activity evoked by the components of a series of tones following the 1st, at inter-stimulus intervals of 0–500 ms. A quantitative assessment of the adaptation effects as a function of inter-stimulus intervals within the tonal sequence, performed over a whole population of studied neurons, showed that the individual time scales of adaptation of neurons varied significantly, which may be crucial for the formation of optimal time windows for the processing of grouping and separation of sound events, which are important both for perception of animal vocalizations and human speech. [ABSTRACT FROM AUTHOR]

A three-layer quasi-geostrophic model was developed to examine the topographic eddies generated around the Eratosthenes Seamount in the southeastern Levantine basin, particularly the dipolar vortex structure, consisting of the anticyclonic Cyprus Eddy and a smaller-scale cyclone. The numerical experiments were carried out using the Contour Dynamics Method, imposing an eastward flow with different inclinations and intensities along the western boundary of the model domain to imitate the Mid-Mediterranean Jet. The dual nature of topographic eddies was previously reported to be generated frequently in a homogeneous ocean approximation, but in the current study, the consideration of baroclinicity primarily simulated a single vortex attributed to the Cyprus Eddy with the small-scale cyclone to be generated occasionally. Also, it was demonstrated that the direction and intensity of the imposed eastward flow along the western boundary of the model domain are the main factors in the formation of the cyclonic vortex. The modeling results showed a qualitative agreement with the geostrophic patterns derived from in-situ observations in the wider sea area of the Eratosthenes Seamount. [ABSTRACT FROM AUTHOR]

We study a possibility of implementing a single-mode DFB heterolaser with inclined (with respect to the surface of the structure) output of the generated radiation. We find the periodic dielectric structure shape that makes it possible to realize the distributed feedback for wavebeams propagating along the structure and, at the same time, to ensure the output of up to 70% of the generated radiation power in the inclined direction. Within the framework of the semiclassical quasi-optical model, the possibility of stationary lasing regimes is shown for finite lateral dimensions of the Bragg structure. [ABSTRACT FROM AUTHOR]

An approximate analytical solution is obtained for the system of equations describing the high-temperature dissociating boundary layer at the lateral surfaces of blunt nose cones in high-speed aircraft, so as to determine the heat fluxes and surface temperatures in aerodynamic heating. Significant use is made of the Reynolds analogy regarding the velocity, temperature, and concentration profiles of the atomic component in a binary gas. To determine the surface temperature of a high-speed aircraft, radiant and conductive heat transfer within the structure is taken into account. [ABSTRACT FROM AUTHOR]

The entry of a meteoroid into the atmosphere and interaction between them are considered. The motion, ablation, and energy deposition of a meteoroid or its fragments moving as a single body are modeled by numerical solution of the meteor physics equations. The main parameter in these equations is the ablation parameter, which is equal to the ratio of the heat transfer coefficient to the effective enthalpy of mass loss. Therefore, the setting of the heat transfer coefficient is of crucial importance in modeling the interaction of a meteoroid with the atmosphere. For the heat transfer coefficient, a correlation is used, which depends on the velocity of the body, its radius, and the atmospheric density. This correlation is an approximation of the published numerical calculations; the convective heat flux is also taken into account. The results of radiative heating simulations in the meteor range of parameters involve some uncertainty since many factors are not taken into account in the computations or are not known. Therefore, an uncertainty parameter is introduced in the formula for the heat transfer coefficient. This parameter is varied to examine the influence of the inaccuracy of setting the ablation parameter on the meteoroid velocity, mass loss, trajectory, and energy deposition along the trajectory. [ABSTRACT FROM AUTHOR]

Iron is a ubiquitous element on Earth, but despite its abundance in the environment, it remains unavailable to many organisms. An antagonistic bacterium P. brenneri 3.5.1 was screened for the production of siderophores—iron-binding compounds on CAS agar and showed halo zones around the colonies. Bacteria secrete catechol-type siderophores at the concentration of 104 μM after 24 h of cultivation. The production of hydroxamate-type siderophores by P. brenneri 3.5.1 was not detected. The siderophore-containing metabolite fraction of P. brenneri 3.5.1 was extracted and purified. In an antagonistic plate assay, it inhibited the growth of Fusarium oxysporum mycelia in the absence of FeCl3. A complete cluster, containing 17 open reading frames, responsible for the production and export of an enterobactin-like siderophore, is present in the genome of P. brenneri 3.5.1. No other siderophore production genes or their homologues were found in the P. brenneri 3.5.1 genome. Therefore, taking together multiple PGP properties of P. brenneri 3.5.1 and after careful assessment of the biosafety of the strain, it could be considered as a biofungicide against Fusarium oxysporum. [ABSTRACT FROM AUTHOR]

Polygala sibirica L. is a rare and endangered plant species that is listed in the Red Book of the Republic of Sakha (Yakutia) under category “3 c” as a species with a narrow ecological limitation to limestone rock outcrops. For the first time, the phytochemical profile of the above-ground phytomass of P. sibirica growing in Central Yakutia was studied, and in vitro culture induction was performed. Using HPLC-MS/MS and tandem mass spectrometry methods, 74 compounds were allegedly identified in methanol extracts of the above-ground phytomass of the P. sibirica, of which 40 compounds were identified for the first time within the genus Polygala L., including 22 polyphenolic compounds: flavones (isoformononetin, syringetin, apigenin 7-O-glucoside, etc.), flavonols (herbacetin, myricetin, etc.), flavan-3-ols (afselequin, epicatechin, etc.), flavanones (hesperitin, eriocitrin), phenolic acid, and anthocyanins. A primary callus culture of P. sibirica was based on leaf explants of intact plants with the study of the dynamics of growth of raw and dried cell biomass. On the basis of callus tissue, indirect morphogenesis with abundant shoot formation is initiated. Thus, the basis has been laid for the subsequent propagation of the rare plant P. sibirica for the purpose of reintroduction in the conditions of the Yakut Botanical Garden. [ABSTRACT FROM AUTHOR]

The paper examines lasing regimes of a 7-core ytterbium fiber laser with a cavity based on an array of fiber Bragg gratings (FBGs) inscribed in each core by femtosecond pulses. Under pumping by a 50 W laser diode, the maximum output power is 33 W, and the differential lasing efficiency is ~70% in both the presence and absence of optical coupling between the cores of an active multicore fiber (MCF). At the same time, a significant difference in the generated optical and radio frequency spectra is observed when use is made of two types of MCFs. It is shown that in an active MCF without coupling, the lasing wavelength in each core is determined by a specific FBG, and the total spectrum is broadened to ~0.2 nm already at the threshold due to a relative shift of the spectral maxima of the FBG in different cores. However, in a fiber with coupling, despite the presence of a similar FBG shift, lasing occurs at a wavelength corresponding to a maximum of the geometric mean reflection coefficient of individual FBGs in the cores. In this case, the total optical spectrum is narrowed down to ~0.04 nm and broadens with power. In the radio frequency spectrum, narrow peaks of intermode beats are observed against the background of a noise substrate, the amplitude of which also increases with power. A model is given to explain the experiments. [ABSTRACT FROM AUTHOR]

This research was aimed at developing descriptive scoring scales for organoleptic assessment of the progression of sugar beet diseases. Preference was given to a five-point scale associated with a five-point scale of acceptability of the resource consumption level during the processing of sugar beets with various technological qualities. The development of the scale for assessing the progression of diseases included the formation of descriptive characteristics of healthy root crops and root crops with signs of degradation by five levels. The descriptive characteristics are focused on the shape of the root crop and the state of its surface and internal tissue. Depending on the disease progression, the signs of degradation of the superficial tissue were accepted in the following increasing order: the occurrence of small lateral roots on the surface; rough or necrotic areas with a loose and flaking structure; depressed areas of dried necrotic tissue, with various sizes and colors and with different locations, occupying a certain surface area; the appearance of mold; transition of the tissue structure from the dense to the soft and loose state. Signs of the state of the internal tissue were characterized by color transition from white-cream to smoke-white; signs of the state of vessels were characterized by color transition from white or light beige to brown, with the formation of cracks of different sizes and with the appearance of mold, as well as by the formation of differently localized necrotic dark brown tissue areas, occupying a certain surface area; and signs of the tissue structure were characterized by the transition from the dense to soft and loose state. Testing of the developed point scales has shown the convenience of their use and correlation of the scale points characterizing the changes in the root crop with the corresponding levels of the scale of resource consumption by the beet sugar factory. Their combined use makes it possible to give a formalized assessment of the level of disease progression and gain insight on the potential costs of its processing. [ABSTRACT FROM AUTHOR]

We study the possibility of using Bragg resonators that implement a three-dimensional distributed feedback mechanism ensuring synchronization of radiation and mode selection under conditions of substantial oversize in three spatial coordinates. To describe the electron–wave interaction in devices of this type, a three-dimensional spatiotemporal averaged model was developed within the framework of the coupled wave approach. On this basis, a planar free-electron maser (FEM) driven by a full-scale electron beam of a sheet configuration with a particle energy of 1 MeV, a current of up to 140 kA, and a cross section of about 1 × 140 cm, which is formed using a high-current accelerating complex U-2 (BINP RAS), was simulated. The possibility of achieving a stable narrow-band oscillation regime in FEMs with a multi-gigawatt power level in the W band with transverse sizes of the proposed resonators from tens to hundreds of radiation wavelengths is demonstrated. [ABSTRACT FROM AUTHOR]

The present article investigates the effect of graphite powder layers on the titanium surface layer during the treatment by the laser-induced plasma-assisted ablation method. Previous research mainly focuses on studying the effect of laser action on the quality of glass plate processing, rather than observing the changes in the substrate morphology caused by the treatment. Varying laser radiation parameters allowed obtaining the arrays of structures and determining the diagram of hardness values depending on the parameters of laser exposure. The method of laser treatment to increase the hardness of the surface layer under a graphite powder layer in contact with a dielectric transparent layer has been proposed and tested; the method has demonstrated a tenfold increase in the hardness of the surface layer. The results can be used in the improvement of cutting tools performance and applied in mechanical engineering or metalworking. [ABSTRACT FROM AUTHOR]

The widespread use of aluminum oxides to synthesize heterogeneous catalysts in petroleum chemistry and oil refining makes it necessary to determine the factors that influence the efficiency of catalytic systems. However, there have been no studies on the effect of amorphous aluminum oxide in aluminum oxide catalysts on the characteristics of a catalytic reaction. The amount of amorphous aluminum hydroxides and oxides is generally not certified, but they can considerably worsen the performance of a catalyst. Amorphous aluminum oxide samples obtained from two different precursors are studied in this work via X-ray phase analysis, low-temperature nitrogen adsorption, electron microscopy, and thermally programmed desorption of ammonia. The catalytic properties of the samples are studied in the vapor phase dehydration of 1-phenylethanol to styrene. It is shown for the first time that the transformation of amorphous aluminum oxide during the catalytic reaction lowers the conversion of alcohol from 84 (for a fresh catalyst) to 64% (for a regenerated sample). The crystallization of amorphous aluminum oxide through high temperature treatment contributes to an increase in catalytic indicators. However, they do not reach the required values because of a strong drop in the textural characteristics and acidic properties of an aluminum oxide surface. [ABSTRACT FROM AUTHOR]

Previously, it was shown that the non-conventional toxin WTX from the venom of the cobra Naja kaouthia, when administered intravenously, caused a decrease in blood pressure (BP) and an increase in heart rate (HR) in rats [13]. To identify the site of the toxin molecule responsible for these effects, we studied the influence of synthetic peptide fragments of the WTX on BP and HR in normotensive male Sprague–Dawley rats under general anesthesia induced by Telazol and Xylazine. It was found that peptides corresponding to the WTX central polypeptide loop, stabilized by a disulfide bond, at intravenous injection at concentrations from 0.1 to 1.0 mg/mL caused a dose-dependent decrease in BP, with the HR increasing only in the first 5–10 min after administration. Thus, WTX fragments corresponding to the central polypeptide loop reproduce the decrease in blood pressure caused by the toxin. [ABSTRACT FROM AUTHOR]

The mechanical properties of deformed semifinished products made of titanium alloys manufactured at different enterprises in the period from the 1970s to the present time are studied. The statistical dependences of the standard mechanical properties on the chemical composition, structure, annealing conditions, and test temperature are revealed from the generalization of the published data and results of industrial tests, industrial control, and own experiments. Recommendations aimed at enhancing the quality of the semifinished products from Ti–6Al–4V alloys are proposed. A prototype has been developed for a "Titanium Alloys" automated information system with the possibility of predicting the properties of titanium alloy semifinished products. [ABSTRACT FROM AUTHOR]

The paper discussed the issue of creating a functional model of the technological process for manufacturing the "cup" part in the UML language. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 2 (SCA2) is a polyglutamine disorder caused by a pathological expansion of CAG repeats in ATXN2 gene. SCA2 is accompanied by cerebellar degeneration and progressive motor decline. Cerebellar Purkinje cells (PCs) seem to be primarily affected in this disorder. The majority of the ataxia research is focused on the motor decline observed in ataxic patients and animal models of the disease. However, recent evidence from patients and ataxic mice suggests that SCA2 can also share the symptoms of the cerebellar cognitive affective syndrome. We previously reported that SCA2-58Q PC-specific transgenic mice exhibit anxiolytic behavior, decline in spatial memory, and a depressive-like state. Here we studied the effect of the activation of the small conductance calcium-activated potassium channels (SK channels) by chlorzoxazone (CHZ) combined with the folic acid (FA) on the PC firing and also motor, cognitive and affective symptoms in SCA2-58Q mice. We realized that CHZ-FA combination improved motor and cognitive decline as well as ameliorated mood alterations in SCA2-58Q mice without affecting the firing rate of their cerebellar PCs. Our results support the idea of the combination therapy for both ataxia and non-motor symptoms in ataxic mice without affecting the firing frequency of PCs. [ABSTRACT FROM AUTHOR]

The paper presents a new method for ice slurry generation, based on a periodic heating of the ice formation surface by an alternating electromagnetic field from an inductor. In comparison with conventional approaches to ice slurry generation, this method is characterized by a decrease in the temperature head between the coolant boiling and solution crystallization, increased reliability, economic efficiency due to the use of thin-walled heat-exchanging materials, and lower energy consumption. The ice generating capacity, energy consumption, and operating modes of the ice slurry generator prototype with induction heating are provided. The obtained results were compared with the indicators of scraper ice slurry generators. [ABSTRACT FROM AUTHOR]

The main problem with hypergraphs is their storage. If the hypergraph does not contain singularities, then sparse matrices are often used to describe it. Adjacency matrices are often used to work with k-uniform hypergraphs, but they take up a large amount of space in computer memory and, in general, storage of k-uniform arrays is not very convenient. Here we propose one solution for describing and storing extremal k-uniform hypergraphs. This base is a unique characteristic of an extremal hypergraph that uniquely describes it. In addition, bases can be used to search for the power of extremal k-uniform hypergraphs. We present base enumeration algorithms and present a hypothesis about the analytical form of formulas describing the cardinality of the set of extremal k-uniform hypergraphs. For this task, the base combination operation, also introduced here, is used. [ABSTRACT FROM AUTHOR]

The dynamics of H2O molecules confined in mesopores of about 3.4 nm in size, formed by amorphous SiO2 pillars separating 2D mordenite nanolayers, was probed by 1H nuclear magnetic relaxation. 1H nuclear magnetic resonance (NMR) spectra evidence the presence of water with different local surroundings and mobility. The temperature dependence of 1H spin–lattice relaxation T1 and relaxation in rotating frame T1ρ indicate the complex behavior of nanoconfined water that can be characterized by different activation energies: freezing (29 kJ/mol), fast rotation (12 kJ/mol), and translational motion (23.6 kJ/mol). [ABSTRACT FROM AUTHOR]

Bismuth(III) hexamethylenedithiocarbamate (HmDtc) [Bi2{S2CN(CH2)6}6] (I) and its solvated with dimethyl sulfoxide form [Bi2(S2CNHm)6]⋅2(CH3)2SO (II) have been obtained. The crystal structure of compound I shows an unusual alternation of two unsymmetrical isomeric pseudo-binuclear [Bi1/1B(HmDtc)3···Bi1A/1C(HmDtc)3] molecules, each of which involves two non-equivalent mononuclear moieties combined by secondary Bi···S bonds. The solvation of complex I leads to the structural unification of isomeric [Bi(HmDtc)3] molecules followed by their self-organization into centrosymmetric pseudo-dimers in the structure of compound II. All HmDtc ligands coordinate in S,S'-anisobidentate mode to form four isomeric (in I) or structurally unique [Bi(HmDtc)3] molecules (in II), whose distorted polyhedra can be approximated by pentagonal pyramid or octahedron. Solvating DMSO molecules are retained in the structure II by C–H···O hydrogen bonds. The analysis of energy dispersive X-ray spectra allowed one to identify the residual matter obtained by thermolysis of the complexes as Bi2S3 with admixture of Bi0. [ABSTRACT FROM AUTHOR]

Intestinal stem cells (ISCs) maintain the epithelial lining of the intestines, but mechanisms regulating ISCs and their niche after damage remain poorly understood. Utilizing radiation injury to model intestinal pathology, we report here that the Interleukin-33 (IL-33)/ST2 axis, an immunomodulatory pathway monitored clinically as an intestinal injury biomarker, regulates intrinsic epithelial regeneration by inducing production of epidermal growth factor (EGF). Three-dimensional imaging and lineage-specific RiboTag induction within the stem cell compartment indicated that ISCs expressed IL-33 in response to radiation injury. Neighboring Paneth cells responded to IL-33 by augmenting production of EGF, which promoted ISC recovery and epithelial regeneration. These findings reveal an unknown pathway of niche regulation and crypt regeneration whereby the niche responds dynamically upon injury and the stem cells orchestrate regeneration by regulating their niche. This regenerative circuit also highlights the breadth of IL-33 activity beyond immunomodulation and the therapeutic potential of EGF administration for treatment of intestinal injury. Mechanisms promoting epithelial regeneration after intestinal injury are poorly understood. Here, authors report that intestinal stem cells produce IL-33 after radiation injury, which induces Paneth cells to produce EGF and promote regeneration. [ABSTRACT FROM AUTHOR]

Alkylation of tris(2,6-dimethoxyphenyl)stibine Ar3Sb, where Ar = 2,6-(MeO)2C6H3, with iodoethane in chloroform resulted in [Ar3EtSb]I, which further reacted with lead(II) nitrate to form [Ar3EtSb]NO3·0.75Н2О. The comparative characterization of the complexes was carried out by X-ray diffraction analysis, IR spectroscopy, and simultaneous thermal analysis. Antimony atoms in stibonium cations have a distorted tetrahedral coordination [CSbC angles 106.80(12)°–115.22(12)° and 105.33(14)°–115.33(14)°]. In a boiling aqueous solution, [Ar3EtSb]I and [Ar3EtSb]NO3·0.75Н2О decompose to tris(2,6-dimethoxyphenyl)stibine. [ABSTRACT FROM AUTHOR]

The genome of aerobic methanotroph Methylococcus capsulatus Bath possesses genes of three biochemical pathways of C1-carbon assimilation: the ribulose monophosphate cycle, the Calvin–Benson–Bassham cycle, and the partial serine cycle. Numerous studies have demonstrated that during methanotrophic growth cells of Methylococcus capsulatus Bath express key enzymes of these routes. In this study, the role of the serine cycle key enzymes, serine-glyoxylate aminotransferase (Sga) and malyl-CoA lyase (Mcl) in metabolism of Methylococcus capsulatus Bath was investigated by gene inactivation. The Δsga mutant obtained by double homologous recombination showed a prolonged lag phase, and after the lag period, the growth rate became similar to that of the wild type strain. The elevated intracellular levels of glutamate, serine, glycine, alanine, methionine, leucine, and succinate suggested significant metabolic changes in the mutant cells. Deletion of the mcl gene resulted in very poor growth and glycine only partially improved growth of the mutant strain. Cells of Δmcl mutant possess lower content of histidine, but enhanced level of alanine, leucine, and lysine than those of the wild type strain. Our data imply the importance of the serine cycle enzymes in metabolism of the methanotroph as well as relationships of the three C1 assimilation pathways in the gammaproteobacterial methanotrophs. [ABSTRACT FROM AUTHOR]