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Using spreading resistance microscopy (SRM) under atmospheric conditions, we demonstrate a stable contrast of the electrical properties on the cleaved cross-section of an undoped InAs/GaSb type-II superlattice with a period of 7.5 nm. It is shown that this contrast is a consequence of the difference in the conductivity of the InAs and GaSb layers of the superlattice. A simple and effective method is proposed for monitoring the structure and electron‒hole subsystem of InAs/GaSb superlattices used in modern IR photodetectors. [ABSTRACT FROM AUTHOR]

Beta-lactam antibiotic cephalexin is poorly recognized by bacterial beta-lactam binding proteins and therefore cannot be reliably detected by a group-specific receptor assay. For effective and rapid monitoring of cephalexin concentration in food products, the test systems based on high-affinity and selective binding of this antibiotic to polyclonal antibodies have been developed. The principle of the method for the test systems of enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay (LFIA) is based on the competitive interaction of (a) cephalexin, potentially contained in the samples, and (b) a cephalexin-protein conjugate immobilized in the wells of a microplate or on the membrane of a test strip, with (c) polyclonal antibodies against cephalexin conjugated with peroxidase or adsorbed on gold nanoparticles. The high specificity of the obtained polyclonal antibodies against cephalexin and the absence of cross-reactivity to a number of cephalosporins, penicillins, and antibiotics of other classes have been confirmed. In the ELISA system in a buffer solution and in a milk matrix, the detection limit, the IC50 value, and the range of detected concentrations were 0.02, 1.0 and 0.025–100 ng/mL respectively. The limit of detection for visual and instrumental determination of cephalexin in the LFIA system were 1.5 and 0.1 ng/mL, and the working range of quantitatively measured concentrations was from 0.05 to 1.5 ng/mL. For both systems, the coefficient of variation of measurements was in the range of 2.5–8.0%. The test systems allow to detect cephalexin in milk without sample preparation. The recovery of cephalexin added to the milk samples was 90.0–106.7%. The presented developments can serve as the basis for kits of reagents for monitoring the content of cephalexin in food products. [ABSTRACT FROM AUTHOR]

Formation and dispersion processes of monoclinic and hexagonal molybdenum-trioxide phases during thermally induced polycondensation of molybdic acid in aqueous medium at 100°C were investigated using dynamic light scattering. Programmed variation of the reaction medium concentration made it possible to control effectively particle nucleation and growth in the solution. Right prismatic crystallites of metastable hexagonal molybdenum trioxide with an average size from 200–500 nm to 10 μm could be obtained. [ABSTRACT FROM AUTHOR]

A chemiluminescence technique was used to establish that, in contrast to TiO2 photocatalysts, TiO2:MoO3 composite photocatalysts suppress the photogeneration of superoxide ions, while the capture of photoelectrons in the MoO3 phase to give reduced Mo(V) states creates conditions for the long-term generation of hydrogen peroxide capable of acting as a biocide. The TiO2:MoO3 accumulating photocatalysts were shown to be fully reusable and the cycle of photocharging followed hydrogen peroxide generation can be repeated multiple times. [ABSTRACT FROM AUTHOR]

Background and aims: We previously reported that Oxy210, an oxysterol-based drug candidate, exhibits antifibrotic and anti-inflammatory properties. We also showed that, in mice, it ameliorates hepatic hallmarks of non-alcoholic steatohepatitis (NASH), including inflammation and fibrosis, and reduces adipose tissue inflammation. Here, we aim to investigate the effects of Oxy210 on atherosclerosis, an inflammatory disease of the large arteries that is linked to NASH in epidemiologic studies, shares many of the same risk factors, and is the major cause of mortality in people with NASH. Methods: Oxy210 was studied in vivo in APOE*3-Leiden.CETP mice, a humanized mouse model for both NASH and atherosclerosis, in which symptoms are induced by consumption of a high fat, high cholesterol "Western" diet (WD). Oxy210 was also studied in vitro using two cell types that are important in atherogenesis: human aortic endothelial cells (HAECs) and macrophages treated with atherogenic and inflammatory agents. Results: Oxy210 reduced atherosclerotic lesion formation by more than 50% in hyperlipidemic mice fed the WD for 16 weeks. This was accompanied by reduced plasma cholesterol levels and reduced macrophages in lesions. In HAECs and macrophages, Oxy210 reduced the expression of key inflammatory markers associated with atherosclerosis, including interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand 2 (CCL2), vascular cell adhesion molecule-1 (VCAM-1), and E-Selectin. In addition, cholesterol efflux was significantly enhanced in macrophages treated with Oxy210. Conclusions: These findings suggest that Oxy210 could be a drug candidate for targeting both NASH and atherosclerosis, as well as chronic inflammation associated with the manifestations of metabolic syndrome. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the dependence of the impact strength of impregnated 3D printed samples on the type of used hardener (PEPA and TETA) and the curing mode after impregnation for samples with different directions of plastic laying during the printing process. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) serve as pivotal mediators of intercellular communication in both health and disease, delivering biologically active molecules from vesicle‐producing cells to recipient cells. In the context of HIV infection, EVs have been shown to carry the viral protein Nef, a key pathogenic factor associated with HIV‐related co‐morbidities. Despite this recognition, the specific localisation of Nef within the vesicles has remained elusive. This study addresses this critical knowledge gap by investigating Nef‐containing EVs. Less than 1% of the total released Nef was associated with EVs; most Nef existed as free protein released by damaged cells. Nevertheless, activity of EV‐associated Nef in downregulating the major cholesterol transporter ABCA1, a critical aspect linked to the pathogenic effects of Nef, was comparable to that of free Nef present in the supernatant. Through a series of biochemical and microscopic assays, we demonstrate that the majority of EV‐associated Nef molecules are localised on the external surface of the vesicles. This distinctive distribution prompts the consideration of Nef‐containing EVs as potential targets for immunotherapeutic interventions aimed at preventing or treating HIV‐associated co‐morbidities. In conclusion, our results shed light on the localisation and functional activity of Nef within EVs, providing valuable insights for the development of targeted immunotherapies to mitigate the impact of HIV‐associated co‐morbidities. [ABSTRACT FROM AUTHOR]

Achromobacter insolitus and Achromobacter aegrifaciens, bacterial degraders of the herbicide glyphosate, were found to induce phosphonatase (phosphonoacetaldehyde hydrolase, EC 3.11.1.1) when grown on minimal media with glyphosate as the sole source of phosphorus. The phosphonatases of the strains were purified to an electrophoretically homogeneous state and characterized. The enzymes differed in their kinetic characteristics and some other parameters from the previously described phosphonatases. The phosphonatase of A. insolitus was first revealed to separate into two stable forms, which had similar kinetic characteristics but interacted differently with affinity and ion-exchange resins. The genomes of the investigated bacteria were sequenced. The phosphonatase genes were identified, and their context was determined: the bacteria were shown to have gene clusters, which, besides the phosphonatase operon, included genes for LysR-type transcription activator (substrate sensor) and putative iron-containing oxygenase PhnHD homologous to monooxygenases PhnY and TmpB of marine organophosphonate degraders. Genes of 2-aminoethylphosphonate aminotransferase (PhnW, EC 2.6.1.37) were absent in the achromobacterial phosphonatase operons; instead, we revealed the presence of genes encoding the putative flavin oxidase HpnW. In silico simulation showed 1-hydroxy-2-aminoethylphosphonate to be the most likely substrate of the new monooxygenase, and a number of glycine derivatives structurally similar to glyphosate to be substrates of flavin oxidase. [ABSTRACT FROM AUTHOR]

Due to the increasing consumer interest in wines with a controlled place of origin, PGI (Protected Geographical Indication) and PDO (Protected Designation of Origin), the most acute question is how to identify them. One of the most effective ways to confirm the place of origin of wine in global practice is a comprehensive study of the elemental profile using statistical analysis methods. In the period from 2020 to 2023, 152 grape samples of grapes were collected from various wineries in Crimea and Kuban. The grape must that was obtained from them was fermented in laboratory conditions. The elemental profile was determined in the prepared wines, which included 71 indicators. In the conducted work, it was revealed that wines from Crimea and Kuban differ statistically significantly in the concentration of the elements B, Ca, Cu, Mn, Na, Ni, Re, Si, Sn and U. At the same time, the contents of the elements U, Sn and Re prevail in wines from Crimea, and those of B, Ca, Cu, Mn, Na, Ni and Si prevail in wines from Kuban. At the same time, methods of univariate and multivariate statistics do not allow us to reliably classify wine samples from Crimea and Kuban by their place of origin. In order to reveal the non-linear dependence of the studied indicators in wines on the geographical place of grape growing, the method of a supervised learning Random Forest was used. After training the model on the dataset, the proportion of its correct predictions was 96%. The model used 61 parameters, among which the most important were Ni, Re, Ba, Rb, Na, U, Sb, Zn, Bi, Ag and Ti. [ABSTRACT FROM AUTHOR]

A power supply system for an unmanned aerial vehicle (UAV) based on a cable connection with a primary source of electrical energy located on the earth's surface is described. The ground power source from a standard three-phase network generates a galvanically isolated, constant output voltage that varies in the range of 350–435 V with an average electric power of up to 10 kW. A circuit based on a step-down type pulse current stabilizer with a subsequent link of a current inverter, a matching transformer, and a rectifier was used. The voltage of the ground power source is fed through the cable-rope to the UAV. The UAV power supply lowers the output voltage to 48 ± 2 V, with an output current of up to 135 A. Experimental data on the operation of the system on a load equivalent and UAVs are presented. [ABSTRACT FROM AUTHOR]

The well-known methods of determining the critical stress intensity factor KIc of the surface layers of materials by indentation of a pyramid for the formation of radial cracks propagating from the vertices of an indent are considered. It is noted that the existing methods for estimating the fracture toughness of a material by indentation do not allow one to determine the crack initiation energy. A technique is proposed to determine the specific crack initiation energy and the specific crack propagation energy using the critical points of a pyramid indentation diagram during instrumented indentation. Energy fracture toughness criterion GIc is found to be related to specific crack propagation energy ωp, which is determined using an indentation diagram, for brittle materials and hardening coatings. This finding makes it possible to develop a technique for rapid estimation of critical stress intensity factor KIc using an indentation diagram recorded during instrumented indentation without measuring the geometric parameters of formed cracks and regardless of their type. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study is to achieve a significant increase in the proliferative activity of mesenchymal stem cells (MSCs) of the bone marrow (BM) at early passages after laser exposure to a suspension of these cells and to estimate the effect of light and heat components of laser radiation on the proliferation of BM MSCs. Methods: The studies were performed on rats BM MSCs. MSC suspension was placed into the wells and heated by using laser radiation (980 nm wavelength) or a water bath at 70 °C providing similar temperature dynamics. The studies were carried out in 3 comparison groups: (1) control suspension of MSCs, which was not subjected to heating in a water bath or laser exposure; (2) MSC suspension, which was heated for in a water bath; and (3) suspension of MSCs, which was subjected to laser exposure. The exposure times for the 2nd and 3rd experimental groups were 10-50 seconds. Results: Under optimal parameters of laser action on the suspension of BM MSCs, a six-fold increase in the number of BM MSCs colonies was registered compared to the control. The role of the light and heat components of laser exposure to MSCs was determined by comparable heating of a suspension of BM MSCs in a water bath, at which only a twofold increase in the number of colonies was maximally obtained. Conclusion: The increase in the MSC proliferation activity occurs due to their Thermo-Photobiomodulation. The result obtained is important for practical use in cell transplantation in the treatment of traumatic injuries of bone, cartilage, and tendon tissues when a rapid and multiple increase in the initial number of autologous BM MSCs is required. [ABSTRACT FROM AUTHOR]

Novel phosphonoacetaldehyde hydrolases (phosphonatases) were isolated from glyphosate-degrading bacteria Achromobacter spp., and their kinetic and molecular characteristics were studied comparatively. Based on MLST analysis of their nucleotide reductase genes, the strains under study were identified as A. aegrifaciens and A. insolitus. Nonspecific induction of phosphonatase was observed in the presence of glyphosate, whereas the natural substrate of the phosphonatase pathway had a negligible effect. Complete genome sequencing disclosed presence of a phosphonatase operon of unusual structure in both bacterial species. In addition to the phosphonatase gene phnX, it also included a gene of a LysR-like transcriptional regulator and two genes of novel proteins with putative functions. [ABSTRACT FROM AUTHOR]

The influence of thermodynamic and kinetic conditions on the interaction of polyclonal antibodies to penicillins with the antibiotics of the penicillin group was studied in the system of a direct enzyme-linked immunosorbent assay (ELISA). Minimal differences in the cross reactions of the polyclonal antibodies with different penicillins were observed when ELISA was carried out at 4°C for 1 h. An increase in temperature and duration of the assay led to an increase in the reactivity of antibodies only to amoxicillin and significantly enhanced differences among the sensitivities of determination of individual penicillins. Under the chosen assay conditions, the following antibody cross-reactivities were obtained: penicillin G, 90%; ampicillin, 100%; and amoxicillin, 110%. The analytical sensitivity was 0.03 ng/mL for ampicillin, and the limit of ampicillin quantification in milk was 0.4 μg/L. The developed group-specific ELISA was used for the determination in milk of seven penicillins that are regulatorily controlled in foods and raw materials of animal origin: penicillin G, ampicillin, amoxicillin, cloxacillin, oxacillin, dicloxacillin and nafcillin. [ABSTRACT FROM AUTHOR]

The distribution of filler particles in composite materials based on molded polyurethane has been studied. Introduction of various particles into molded polyurethane improves its mechanical and performance properties. Based on the research results, it was concluded that the most uniform distribution of particles is observed in talc-based composites (coefficient of variation of 7.3%, and the greatest spread of particles in composites with basalt fiber of 28.3%). [ABSTRACT FROM AUTHOR]

The dynamics of the temperature of particles with a characteristic size of 10–7–10–6 m at the boundary of Earth's atmosphere and outer space is considered. Using graphite as an example, it is shown that at an altitude of 80–90 km from Earth's surface, particles with a size of ∼5 × 10–7 m or less can be heated above the temperature of the beginning of the glow (~900 K), reaching temperatures of more than 2000 K with a light turquoise glow. Based on the results obtained, it is concluded that the silvery clouds observed in the false dawn and after sunset from Earth's surface are a cluster of white-hot nanoparticles. [ABSTRACT FROM AUTHOR]

Additive technologies are now widely used for the production of complex precise parts and have high potential for the production of forming dies. In this work, hot-forming dies optimized for additive manufacturing were developed and produced with wire arc direct energy deposition (WA-DED) and laser powder bed fusion (L-PBF) technologies. The concept of lightweight hot-forming dies with a 2D-lattice structure was developed, which reduced the weight of each die by 56%, from 14.2 kg to 6.1 kg, in production using L-PBF. Maraging/precipitation-hardened steel 17-4PH was used as an alternative to traditional hot-working steels with slightly lower mechanical properties and a much higher processability in the additive manufacturing process. The workability of the manufactured dies was confirmed by forging tests on an industrial screw press. [ABSTRACT FROM AUTHOR]

It was shown by IR spectroscopy that the mechanism of formation of titanium dioxide (TiO2) tubulenes during the mechanochemical activation of nanodispersed hydrated TiO2 under the conditions of high contact pressure includes a stage of aggregation of the TiO2 particles through the formation of Ti–O–Ti bridges. During further mechanical action the oxide blocks are transformed into two-dimensional crystalline structures with the formation of tubulenes. [ABSTRACT FROM AUTHOR]

Abstract—Studies on the dynamic viscosity of composites based on a two-component polyurethane compound with fillers in the form of shungite, talc, and basalt fibers (3 vol %) with addition of dichloromethane as an organic solvent (10 vol %) are presented. Based on the results of the studies, it is revealed that the most rational composites for casting into elastic molds are the composites containing shungite and talc as fillers. [ABSTRACT FROM AUTHOR]

Substantial background level of replication stress is a feature of embryonic and induced pluripotent stem cells (iPSCs), which can predispose to numerical and structural chromosomal instability, including recurrent aberrations of chromosome 12. In differentiated cells, replication stress-sensitive genomic regions, including common fragile sites, are widely mapped through mitotic chromosome break induction by mild aphidicolin treatment, an inhibitor of replicative polymerases. IPSCs exhibit lower apoptotic threshold and higher repair capacity hindering fragile site mapping. Caffeine potentiates genotoxic effects and abrogates G2/M checkpoint delay induced by chemical and physical mutagens. Using 5-ethynyl-2′-deoxyuridine (EdU) for replication labeling, we characterized the mitotic entry dynamics of asynchronous iPSCs exposed to aphidicolin and/or caffeine. Under the adjusted timing of replication stress exposure accounting revealed cell cycle delay, higher metaphase chromosome breakage rate was observed in iPSCs compared to primary lymphocytes. Using differential chromosome staining and subsequent locus-specific fluorescent in situ hybridization, we mapped the FRA12L fragile site spanning the large neuronal ANKS1B gene at 12q23.1, which may contribute to recurrent chromosome 12 missegregation and rearrangements in iPSCs. Publicly available data on the ANKS1B genetic alterations and their possible functional impact are reviewed. Our study provides the first evidence of common fragile site induction in iPSCs and reveals potential somatic instability of a clinically relevant gene during early human development and in vitro cell expansion. [ABSTRACT FROM AUTHOR]

A two-channel pulsed power supply for an imaging system with brightness amplification and independent synchronous laser illumination is designed. The power supply generates synchronized high-voltage pulses with a frequency of 16-24 kHz, an average electrical power of up to 1.2 kW, and an adjustable amplitude of up to 6.2 kV to pump copper bromide gas discharge tubes with independent control of the temperature parameters of the active medium. To generate pumping pulses for laser media, we used a two-channel thyratron circuit with a common source of stabilized voltage provided by a step-down pulse stabilizer and a bridge inverter-based circuit for the pulsed charge of storage capacitors. The voltage equalization on the storage capacitors is carried out by means of magnetic coupling of the charging inductances wound on a common core. Adjustable delay lines based on variable inductances provide synchronous operation of two brightness amplifiers with a synchronization accuracy of lasing pulses of ±1 ns. The power supply demonstrated stable operation with two gas discharge tubes having different characteristics, including those with different types of electrodes. It has been integrated into a laboratory facility for the study of high-energy materials combustion. [ABSTRACT FROM AUTHOR]

Feasibility was demonstrated for the spectroscopic identification of solid solution phases varying in composition formed upon obtaining mixed molybdenum–vanadium oxides by solvothermal methods. This method is based on the change in the ν(V=O) adsorption bands due to the partial substitution of vanadium sites in the crystal lattice by molybdenum in the mixed oxide. [ABSTRACT FROM AUTHOR]

Ternary mixture of choline chloride, ethylene glycol and urea (molar ratio 1 : 1 : 1) has been proposed as non‐aqueous media for the electrochemical plating in galvanostatic mode of tin‐silver alloy coatings. The conditions for the deposition of an alloy with a composition and melting temperature close to the eutectic, which is in demand for microassembly in the electronic industry, have been determined. The significant features on the simultaneous tin(II) and silver(I) reduction and the alloy formation are revealed. It has been determined that silver(I) is reduced from the solution both electrochemically and by the galvanic displacement with freshly deposited tin. The presence of silver on the surface of the coatings initiates underpotential tin(II) reduction. The interactions of components in the non‐aqueous electrolyte have been studied for the first time by IR spectroscopy, and the formation of coordination compounds between tin(II) and silver(I) ions and solvent molecules has been revealed. [ABSTRACT FROM AUTHOR]

This article considers a methodological approach to recognize the intrusion of objects into a protected area using an optoelectronic robotic complex, which is based on the existence of a certain characteristic space (a set of signal and geometric features) for each class and type of object. The solved problem of comparing Bayesian a posteriori probabilities of classes (types) of objects is reduced to calculating a priori probabilities and energy distribution functions of signals and geometric parameters of objects, i.e., the likelihood functions of a feature for a specific class (type) of an object. Based on the obtained parameters, the dependences of the probability of correct recognition, omission, false recognition, and confusion of objects on the coefficient of distinctness when the object's signal energy deviates from the standard energy are analyzed. The results obtained are required to solve the problem of the adaptive group control of robotic complexes when solving operational and tactical and tasks in an uncertain dynamic environment. [ABSTRACT FROM AUTHOR]

In a broad variety of configurations in technology and industrial applications, the properties of liquid metal flows subjected to strong magnetic fields, are largely governed by the dynamics of coherent structures, known to settle several basic types, such as thin shear layers, forming near the walls or within the fluid domain, vortices extended along the field, or planar and round jets. In some cases, these structures are created by the design, like a submerged jet formed by a sudden expansion from the nozzle into a blanket channel, or jets formed behind some flow obstruction. In the other cases this may be due to instability and evolution of secondary structures, for example, descending and ascending jets appearing as a result of convective instability in blanket channels. In this study, we undertake an attempt to affect liquid metal flow via inlet disturbance formed by a simple rod placed along the magnetic induction lines. The disturbance can generate flat jets behind the rod and, furthermore, a sustainable flow of anisotropic vortical perturbations further downstream the flow. We seek to analyze the most important mechanisms of the flow dynamics and effects of magnetic field on the integral system properties of enhancing mixing, mass and heat transport for such flow. The most optimal regimes of vortex generation are found to be governed by the magnetic interaction parameter (Stuart number). The exact ratio of the optimal Stuart number is found to be in a range between 20 and 40, based on the channel double width as a characteristic size. The observed vortices attain quasi‐2D shape and exist at a length of dozens of duct calibers, being the strongest at higher flow rates. The obtained flow regimes and their turbulent properties are also found to resemble significant similarity to the results on quasi‐2D turbulence found in prior studies of channel and duct flows under spanwise magnetic field. [ABSTRACT FROM AUTHOR]

Autoimmune gastritis (AIG) is an immuno-mediated disease characterized by the production of antibodies to the parietal cells of the stomach, which leads to the loss of the internal Castle factor and decrease in the production of hydrochloric acid. Diagnosis of AIG remains difficult due to the lack of symptoms at early stages, ineffective or costly screening strategies, and incomplete established etiology. Patients with AIG are at high risk of developing malignant neoplasms and neuroendocrine tumors, and they would greatly benefit from any means to predict the likelihood of developing and the severity of a possible disease. Here, we aim to summarize data on the genetic nature of AIG. We will also describe the clinical picture of AIG, Helicobacter pylori association with it, and elaborate on the pathogenesis of the disease. [ABSTRACT FROM AUTHOR]

Background: The present article considers the influence of malt with various adjuncts on beer organic compounds and taste profile composition, with more attention paid to the phenol complex change. The topic under consideration is relevant since it studies the interactions of phenolic compounds with other biomolecules, and expands the understanding of the adjuncts organic compounds contribution and their joint effect on beer quality. Methods: Samples of beer were analyzed at a pilot brewery using barley and wheat malts, barley, rice, corn and wheat, and then fermented. The beer samples were assessed by industry-accepted methods and using instrumental analysis methods (high-performance liquid chromatography methods—HPLC). The obtained statistical data were processed by the Statistics program (Microsoft Corporation, Redmond, WA, USA, 2006). Results: The study showed that at the stage of hopped wort organic compounds structure formation, there is a clear correlation between the content of organic compounds and dry substances, including phenolic compounds (quercetin, catechins), as well as isomerized hop bitter resines. It is shown that the riboflavin content increases in all adjunct wort samples, and mostly with the use of rice—up to 4.33 mg/L, which is 9.4 times higher than the vitamin levels in malt wort. The melanoidin content in the samples was in the range of 125–225 mg/L and its levels in the wort with additives exceeded the malt wort. Changes in β-glucan and nitrogen with thiol groups during fermentation occurred with different dynamics and depending on the adjunct's proteome. The greatest decrease in non-starch polysaccharide content was observed in wheat beer and nitrogen with thiol groups content—in all other beer samples. The change in iso-α-humulone in all samples at the beginning of fermentation correlated with a decrease in original extract, and in the finished beer there was no correlation. The behavior of catechins, quercetin, and iso-α-humulone has been shown to correlate with nitrogen with thiol groups during fermentation. A strong correlation was shown between the change in iso-α-humulone and catechins, as well as riboflavin and quercetin. It was established that various phenolic compounds were involved in the formation of taste, structure, and antioxidant properties of beer in accordance with the structure of various grains, depending on the structure of its proteome. Conclusions: The obtained experimental and mathematical dependences make it possible to expand the understanding of intermolecular interactions of beer organic compounds and take a step toward predicting the quality of beer at the stage of using adjuncts. [ABSTRACT FROM AUTHOR]

Meta-structures based on periodic ferroelectric inhomogeneities in a dielectric matrix were implemented, which demonstrated tunability at a relatively low effective dielectric permittivity and low microwave losses. Glass-ceramic composite consisting of low melting glass and barium-strontium titanate was successfully incorporated into the periodic holes of dielectric matrix to form tunable metamaterial structure. The studied composite samples showed a relative dielectric permittivity of 18 with a dielectric loss level of 0.02 at a frequency of 2 GHz. The tunability of the entire structure under the applied electric field of 2 V/μm was 4%, which is a promising result for microwave tunable applications. [ABSTRACT FROM AUTHOR]

A pulsed magnetron system generating high-energy microwave pulses with a frequency of 400 Hz and an average power of 0.5 kW is described. To generate a magnetron current pulse, a circuit with 12 identical transistor modules with an operating voltage of 800 V, which are connected in series to the primary winding of a high-voltage pulse transformer with a transformation ratio of 3.5, is used. Thus, a voltage pulse with an amplitude of up to 26 kV and a 25-A current with an adjustable duration of 100–500 ns is formed. Experimental data of the system operation into the pulsed microwave magnetron and an equivalent load are presented. [ABSTRACT FROM AUTHOR]

We studied the effect of laser radiation of moderate intensity with a wavelength of 970 nm on the efficiency of colony formation of rat bone marrow mesenchymal stem cells (MSC) in vitro. In this case, photobimodulation and thermal heating of MSC occur simultaneously. This combined laser treatment allows increasing the number of colonies by 6 times in comparison with the control and by more than 3 times in comparison with thermal heating alone. The mechanism of such an increase is associated with combined thermal and light effects of laser radiation of moderate intensity, which stimulates cell proliferation. This phenomenon can be used as the basis for solving the most important task of cell transplantation, associated with the expansion of autologous stem cells and activation of their proliferative potential. [ABSTRACT FROM AUTHOR]

A bioanalytical sandwich system for the quantitative determination of the recombinant beta-lactam receptor BlaR-CTD, which possesses the ligand-binding activity and immunoreactivity, was developed. In this test system, BlaR-CTD present in a biological liquid or a calibration sample binds to ampicillin immobilized in a microplate well through the receptor site and interacts with specific polyclonal antibodies through the epitopes of the peripheral structure. The analytical sensitivity of the method turned out to be 2 ng/mL; the working range was 5–215 ng/mL. The biological activity was monitored and the stability of BlaR-CTD was evaluated during its heterologous expression, isolation and preparation of reagent forms. The highly purified recombinant beta-lactam receptor BlaR-CTD was obtained. It was shown that this protein had a sufficiently high resistance to denaturation by chaotropic agents (urea and guanidine hydrochloride) and was stable over a wide pH range. In addition, the constructions and procedures of applying competitive systems for the bioassay of beta-lactam antibiotics based on the receptor and antigenic properties of BlaR-CTD in microplates (analytical sensitivity 0.02 ng/mL, IC50 = 0.28 ng/mL) and chromatographic test strips (detection limit 1–2 ng/mL) were proposed. [ABSTRACT FROM AUTHOR]

In the present study, pins made from the novel Mg-2Zn-2Ga alloy were installed within the femoral bones of six Wistar rats. The level of bioresorption was assessed after 1, 3, and 6 months by radiography, histology, SEM, and EDX. Significant bioresorption was evident after 3 months, and complete dissolution of the pins occurred at 6 months after the installation. No pronounced gas cavities could be found at the pin installation sites throughout the postoperative period. The animals' blood parameters showed no signs of inflammation or toxication. These findings are sufficiently encouraging to motivate further research to broaden the experimental coverage to increase the number of observed animals and to conduct tests involving other, larger animals. [ABSTRACT FROM AUTHOR]

As-prepared mesoporous silicon nanoparticles, which were synthesized by electrochemical etching of crystalline silicon wafers followed by high-energy milling in water, were explored as a sonosensitizer in aqueous media under irradiation with low-intensity ultrasound at 0.88 MHz. Due to the mixed oxide-hydride coating of the nanoparticles' surfaces, they showed both acceptable colloidal stability and sonosensitization of the acoustic cavitation. The latter was directly measured and quantified as a cavitation energy index, i.e., time integral of the magnitude of ultrasound subharmonics. The index turned out to be several times greater for nanoparticle suspensions as compared to pure water, and it depended nonmonotonically on nanoparticle concentration. In vitro tests with Lactobacillus casei revealed a dramatic drop of the bacterial viability and damage of the cells after ultrasonic irradiation with intensity of about 1 W/cm2 in the presence of nanoparticles, which themselves are almost non-toxic at the studied concentrations of about 1 mg/mL. The experimental results prove that nanoparticle-sensitized cavitation bubbles nearby bacteria can cause bacterial lysis and death. The sonosensitizing properties of freshly prepared mesoporous silicon nanoparticles are beneficial for their application in mild antibacterial therapy and treatment of liquid media. [ABSTRACT FROM AUTHOR]

An experimental study aimed at comparing different methods for assessing the Saccharina japonica commercial stock, a target commercial kelp species in the Russian Far East, was carried out in 2021. Samples were collected from 11 sites from aboard the R/V Ubezhdenny and small-displacement vessels. Study sites were located in the northwestern Tatar Strait within an area stretching for 44 km south of Sovetskaya Gavan Bay, between Cape Krasny Partizan and Cape Korovin (from 48°58′ N, 140°23′ E to 48°37′ N, 140°11′ E), in areas of traditional commercial harvesting of S. japonica. Four assessment methods were compared: (1) based on independent visual estimates of plant cover (PC) by two observers from the surface; (2) based on independent estimates of PC by two observers using a series of images obtained from a small remotely operated underwater vehicle (ROV), or drone; (3) based on PC estimates made by a diver; and (4) based on quantitative samples made by a diver. The stock assessment values based on the first three methods are comparable and differ by 1.2–1.7 times. The stock values based on diver-collected samples are 2.4–4.1 times higher than the first three due to artifacts inherent in the diving method. To eliminate inaccuracies, samples should be collected by divers under the control from the surface using an underwater drone. PC estimates by divers are impractical. Visual PC estimates from the surface are simple and inexpensive, but do not allow documentation of survey results. To assess commercial kelp resources, the use of an underwater drone, which provides adequate abundance assessment and complete documentation of materials obtained, is the optimal approach. [ABSTRACT FROM AUTHOR]

A method for photogrammetric counts of Pacific salmon using consumer-grade unmanned aerial vehicles (UAVs) has been developed. It is based on estimation of the abundance of spawners and spawning redds by photogrammetric processing of aerial images taken with UAVs at monitoring sites and analysis of photogrammetric products (orthomosaics and digital elevation models, DEMs) in geographic information systems (GIS). The estimates of relative abundance for the monitoring sites are extrapolated to the area of watercourses of the respective basin suitable for spawning grounds to calculate the total abundance. It has been shown for the first time that DEMs of the watercourse bottom allow visualization and counting of redds. The components of the method are described in detail: work planning, photography, data processing, fish abundance estimation, data analysis and visualization, and web-publication. Recommendations for choosing a UAV, its accessories, and software for flight, photogrammetry, and GIS are provided. This approach will contribute to the objectivity of salmon counts and provide gradual transition from subjective aerovisual abundance estimation methods towards a provable and verifiable digital basis. [ABSTRACT FROM AUTHOR]

The ODM-2F sorbent based on diatomite with a porosity of ~75% is used as a filter material for effective wastewater treatment at a thermal power plant. At pH 6.0‒8.0, when metals Ni, Zn, Cu are in the form of Me2+ and MeON+ cations, the process of their separation per MM is described by two types of adsorption isotherms – Langmuir and S-shaped. For unmodified MM in the Ca-form, S-shaped isotherms are characteristic. For MM, partially and completely converted to the Na-form, metal adsorption isotherms acquire a Langmuir appearance. An increase in the salt background of the solution (100‒800 mg/dm3 NaCl) does not reduce the sorption capacity for copper (120‒130 mg/g), unlike organic resins. The adsorption of nickel, zinc, and copper cations at a pH of 7‒8 per MM in the Ca-form (11‒46 mg/g) is lower than in the Na-form (17‒75 mg/g), which is due to the high energy costs when replacing Ca2+ with metal counterions compared to Na+. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to investigate the specifics of the relationship between audit committee characteristics and earnings management in Russian listed companies. This research is driven by the possibility of placing this relationship within the context of a specific institutional environment for company performance. Design/methodology/approach: The authors apply a panel study of 184 Russian listed companies for the period 2014–2018. In addition to the standard fixed effects model, the authors test the results for potential endogeneity with two-stage least squares (2SLS) analysis. Findings: The results show that audit committee representation on the board of directors results in some mitigation of earnings management. Results reveal that a higher level of audit committee independence and the presence of financial expertise on the committee are associated with lower earnings management. However, companies with relatively busy directors on audit committees are more inclined to practice earnings management. The study's findings hold after testing for endogeneity of audit committee independence. The authors also reveal that some audit committee characteristics (for example, audit committee independence; its level of expertise) alleviate earnings management in listed state-owned companies (SOEs) more strongly than in listed non-SOEs. Originality/value: The results add to the ongoing debate on the role of corporate governance mechanisms in mitigating earnings management in emerging markets by taking into account the type of ownership (state-owned vs private) as a moderating variable. This study reveals, in particular, that the effect of certain audit committee characteristics on earnings management is more prominent in listed SOEs than in listed non-SOEs. [ABSTRACT FROM AUTHOR]

The dependence of acoustic cavitation thresholds in aqueous suspensions of porous silicon nanoparticles (pSiNPs) on the degree of hydrophobicity of their surface has been studied. Nanoparticles with an average size of 100 nm were prepared by mechanical grinding of porous silicon (pSi) films in ethanol. According to IR spectroscopy data, such pSiNPs are initially characterized by a hydrophilic surface. To obtain amphiphilic (hydrophobic–hydrophilic) nanoparticles, pSi films were hydrophobized before grinding by surface modification with octadecylsilane. When hydrophobic pSi films are ground in ethanol to nanoparticles, silicon–silicon bonds are broken, followed by their oxidation, due to which the surface is partially hydrophilized. It has been shown that the threshold of acoustic cavitation in suspensions of amphiphilic pSiNPs is significantly reduced compared to that of hydrophilic pSiNPs. The threshold value of acoustic cavitation in a suspension of amphiphilic nanoparticles at a concentration of 1 mg/mL remained almost constant for 5 days. The results obtained are important for the development of methods for sonodynamic therapy of cancer using pSiNPs. [ABSTRACT FROM AUTHOR]

Doxorubicin, which is widely used to treat a broad spectrum of malignancies, has pronounced dose-dependent side effects leading to chronic heart failure development. Nicotinamide riboside (NR) is one of the promising candidates for leveling the cardiotoxic effect. In the present work, we performed a comparative study of the cardioprotective and therapeutic actions of various intravenous NR administration modes in chronic doxorubicin-induced cardiomyopathy in Wistar rats. The study used 60 mature male SPF Wistar rats. The animals were randomized into four groups (a control group and three experimental groups) which determined the doxorubicin (intraperitoneally) and NR (intravenous) doses as well as the specific modes of NR administration (combined, preventive). We demonstrated the protective effect of NR on the cardiovascular system both with combined and preventive intravenous drug administration, which was reflected in a fibrous tissue formation decrease, reduced fractional-shortening decrease, and better antioxidant system performance. At the same time, it is important to note that the preventive administration of NR had a more significant protective effect on the animal organism as a whole. This was confirmed by better physical activity parameters and vascular bed conditions. Thus, the data obtained during the study can be used for further investigation into chronic doxorubicin-induced cardiomyopathy prevention and treatment approaches. [ABSTRACT FROM AUTHOR]

ApoB-100 is a member of a large lipid transfer protein superfamily and is one of the main apolipoproteins found on low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) particles. Despite its clinical significance for the development of cardiovascular disease, there is limited information on apoB-100 structure. We have developed a novel method based on the "divide and conquer" algorithm, using PSIPRED software, by dividing apoB-100 into five subunits and 11 domains. Models of each domain were prepared using I-TASSER, DEMO, RoseTTAFold, Phyre2, and MODELLER. Subsequently, we used disuccinimidyl sulfoxide (DSSO), a new mass spectrometry cleavable cross-linker, and the known position of disulfide bonds to experimentally validate each model. We obtained 65 unique DSSO cross-links, of which 87.5% were within a 26 Å threshold in the final model. We also evaluated the positions of cysteine residues involved in the eight known disulfide bonds in apoB-100, and each pair was measured within the expected 5.6 Å constraint. Finally, multiple domains were combined by applying constraints based on detected long-range DSSO cross-links to generate five subunits, which were subsequently merged to achieve an uninterrupted architecture for apoB-100 around a lipoprotein particle. Moreover, the dynamics of apoB-100 during particle size transitions was examined by comparing VLDL and LDL computational models and using experimental cross-linking data. In addition, the proposed model of receptor ligand binding of apoB-100 provides new insights into some of its functions. [ABSTRACT FROM AUTHOR]

The relevance of the study is determined by the problem of choosing the optimal scale for identifying plant growth phases to determine the best terms for conducting agrotechnical operations for the care of sorghum plants. The purpose of the experiment was to apply a plant growth regulator with higher efficiency during crop growth stages 21, 31, 37 (BBCH) and III, IV, VI-VII on the Kuperman scale. Field and laboratory research methods were used in the study. The experiment was conducted in the Forest-Steppe zone of Ukraine, two sorghum varieties of Sorghum bicolor and Sorghum saccharatum were treated with PGR. Foliar application of PGR (0.5 L/ha) in the BBСH stages 21 and 31 provides 2.8 and 4.9% better results than in stages III and IV of the Kuperman scale (the latter is based on the complex morphophysiological analysis to identify I to VII CGS). Foliar application of the PGR in microstage 21 (BBCH) promoted faster development and an increase in grain yield in sorghum varieties (0.19 t/ha in Odeskyi 205 and 0.12 t/ha in Lan 59) compared to application in stage III (Kuperman). A similar effect of the PGR applied in microstage 21 (BBCH) compared to stage III (Kuperman) was recorded for two sweet sorghum hybrids: in Dovista, an increase in the yield of biomass was 1.6t/ha, dry matter - 0.7t/ha, and sugar content in the stem juice - 0.0%, while these indices in Huliver amounted to 1.6t/ha, 0.7t/ha, and 0.2% respectively. Therefore, the BBCH scale is recommended to adopt for PGR application, and foliar application of PGR should be conducted in the 21 and 31. The practical value of the study lies in the selection of the scale of growth and development of sorghum crops and the terms of application of foliar fertilisation, optimal for the conditions of Ukraine. The study is useful from the practical standpoint of conducting foliar fertilisation of plants in production and as a theoretical assessment of plant growth and development scales for students and researchers. [ABSTRACT FROM AUTHOR]

Wide variations of 87Sr/86Sr (0.70825‒0.70924) have been established at the Porozhinsk deposit in manganese ores and carbonates ascribed to the Pod"emsk Formation. These data, together with variations in the carbon (δ13C = –14.6...2.0‰, PDB) and oxygen (δ18О = 19.4...28.3‰, SMOW) isotope composition indicate different conditions of the formation of the studied rocks. The 87Sr/86Sr values in the studied dolomites of the Porozhinsk deposit are much higher than those of carbonate rocks (dolomites, limestones) of the Pod"emsk Formation from the Chapa River section. The position of the 87Sr/86Sr values of dolomites from the Porozhinsk deposit on the secular 87Sr/86Sr variation curve for Late Proterozoic ocean (Kuznetsov et al., 2014) suggests that the carbonate rocks attributed to the Pod"emsk Formation at the Porozhinsk deposit have younger age than carbonates of the Pod"emsk Formation from the Chapa River section. The Mn/Sr values usually taken as a criterion for the degree of secondary alteration of carbonates (in interpreting 87Sr/86Sr variations and discussing the suitability of the material for chemostratigraphic constructions) are not suitable for rocks formed in manganese ore sedimentation basins. [ABSTRACT FROM AUTHOR]

Cholesterol oxidase is a highly demanded enzyme used in medicine, pharmacy, agriculture, chemistry, and biotechnology. It catalyzes oxidation of 3β-hydroxy-5-ene- to 3-keto-4-ene- steroids with the formation of hydrogen peroxide. Here, we expressed 6xHis-tagged mature form of the extracellular cholesterol oxidase (ChO) from the actinobacterium Nocardioides simplex VKM Ac-2033D (55.6 kDa) in Escherichia coli cells. The recombinant enzyme (ChONs) was purified using affinity chromatography. ChONs proved to be functional towards cholesterol, cholestanol, phytosterol, pregnenolone, and dehydroepiandrosterone. Its activity depended on the structure and length of the aliphatic side chain at C17 atom of the steroid nucleus and was lower with pregnenolone and dehydroepiandrosterone. The enzyme was active in a pH range of 5.25÷6.5 with the pH optimum at 6.0. Kinetic assays and storage stability tests demonstrated that the characteristics of ChONs were generally comparable with or superior to those of commercial ChO from Streptomyces hygroscopicus (ChOSh). The results contribute to the knowledge on microbial ChOs and evidence that ChO from N. simplex VKM Ac-2033D is a promising agent for further applications. [ABSTRACT FROM AUTHOR]