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In this work, we propose a new algorithm for detecting the indicator of delayed cerebral ischemia from video-EEG monitoring data. The proposed algorithm combines an algorithm for detecting the effect of interchannel time-frequency synchronization of wavelet spectrogram ridges of EEG signals and an algorithm for detecting motion artifacts in video recording frames. Using the EEG analysis algorithm, we identify an indicator that is used to predict the occurrence of ischemia. By analyzing the optical flow, we exclude time intervals in which erroneous fixation of ischemia indicators is possible. The developed algorithm was tested on the clinical data of video-EEG monitoring. The preliminary results obtained during testing confirm the fundamental possibility of detecting the ischemia indicators and the acceptable accuracy of detecting motion artifacts leading to an erroneous diagnosis.

This work is devoted to revealing the electrophysical regularities of the process of jet electrolytic-plasma processing of materials. Electrostatic studies were carried out in the COMSOL Multiphysics program. The influence of the voltage between the electrodes, the geometrical parameters of the hollow cathode tube, the shape of the drop, and the height of the interelectrode gap on the strength and distribution of the electric field is estimated. The data on the magnitude and location of the maximum electric field strength have been refined. It is shown that the studied parameters significantly affect the surface morphology in the zone of formation of an electric discharge, which is confirmed by the results of the experiments. The modeling of the treatment zone with a jet of electrolyte plasma was performed for different parameters. It is shown that there are competing mechanisms of material removal. Surface modeling for different types of machining was carried out and the parameters of the layer to be removed were calculated. The research results can be applied to the development of technological processes for jet electrolytic-plasma treatment of turbine blades.

Aim. To study the associations of blood proteins with the presence of unstable atherosclerotic plaques in the arteries in patients with coronary artery disease using the quantitative proteomic analysis.Materials and methods. The study included patients with coronary artery disease (n = 40); the average age of patients was 58 ± 7 years. Material for the study was blood serum. Protein concentrations in serum samples were determined using the PeptiQuant Plus Proteomics Kit (Cambridge Isotope Laboratories, USA). Protein fractions were identified using the liquid chromatograph and tandem mass spectrometer Q-TRAP 6500.Results. Mass spectrometry revealed an increased concentration of proteins, such as fibrinogen, fibulin-1, and complement factor H, in the serum samples of patients with unstable atherosclerotic plaques. It took place with a simultaneous decrease in the levels of α 2-antiplasmin, heparin cofactor II, coagulation factor XII, plasminogen, prothrombin, vitronectin, complement proteins (C1, C3, C7, C9), and complement factor B. The differences were considered significant at p < 0.05. It was revealed that the presence of unstable atherosclerotic plaques was associated with the level of fibulin-1 (Exp(B) = 1.008; р = 0.05), plasminogen (Exp(В) = 0.995; р = 0.027), and coagulation factor X (Exp(В) = 0.973; р = 0.037).Conclusion. An increased concentration of fibulin-1 can be considered as a potential biomarker of unstable atherosclerotic plaque development in coronary artery disease. The possibility of using the studied proteins as biomarkers of unstable atherosclerotic plaques requires further studies on their potential role in the development of this disease.

Objective: To evaluate the performance and short-term capacity of the diepoxy-treated bovine jugular vein conduit in large animals during 6-month follow-up.Methods: Thirteen diepoxy-treated bovine jugular vein conduits were implanted into the pulmonary artery of young mini-pigs. During the follow-up, graft function was tested using transesophageal echocardiography. The animals were withdrawn at 6 months, and the explanted conduits were assessed histologically.Results: All the conduits were successfully implanted without any surgical complications. All the animals survived throughout the follow-up. By the end of the follow-up period, the pressure gradient increased on five animals’ conduits including one case of mismatch between the conduit and the native pulmonary artery, two cases of distal stenosis, and two case of endocarditis. No significant increase in valve regurgitation or conduit thrombosis was observed during the follow-up. In conduits without dysfunction, the structure of the walls and leaflets was intact. A thin fibrous tissue covered the conduit inner wall with complete surface endothelialization. Neither signs of degeneration or calcification nor inflammatory cells were found in the conduit wall or leaflets. Neointima proliferation without calcium deposits was observed in two distally stenosed conduits. Inflammatory cells consisting of multinucleated macrophages, lymphocytes, and histiocytes were found in the adventitia. There were no inflammatory cells in the media or intima, and the leaflets showed no changes.Conclusion: Diepoxy-treated bovine jugular vein demonstrated acceptable performance, good endothelialization, and low tendency to thrombosis and calcium accumulation in the wall and leaflets. Received 31 October 2022. Revised 25 November 2022. Accepted 28 November 2022. Funding: The study was supported by Russian Science Foundation (grant No. 22-25-20102). Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: N.R. Nichay, I.Yu. Zhuravleva, A.V. Bogachev-ProkophievData collection and analysis: N.R. Nichay, Yu.Yu. Kulyabin, I.S. Zykov, E.V. Boyarkin, O.Yu. Malakhova, E.V. Kuznetsova, T.P. Timchenko, Ya.L. Rusakova, I.S. Murashov, A.A. DokuchaevaStatistical analysis: N.R. Nichay, I.Yu. ZhuravlevaDrafting the article: N.R. Nichay, I.Yu. Zhuravleva, Yu.Yu. Kulyabin, I.S. Zykov, E.V. Boyarkin, O.Yu. Malakhova, T.P. Timchenko, Ya.L. Rusakova, I.S. Murashov, A.A. DokuchaevaCritical revision of the article: N.R. Nichay, I.Yu. Zhuravleva, Yu.Yu. Kulyabin, A.A. Dokuchaeva, A.V. Bogachev-ProkophievFinal approval of the version to be published: N.R. Nichay, I.Yu. Zhuravleva, Yu.Yu. Kulyabin, I.S. Zykov, E.V. Boyarkin, O.Yu. Malakhova, E.V. Kuznetsova, T.P. Timchenko, Ya.L. Rusakova, I.S. Murashov, A.A. Dokuchaeva, A.V. Bogachev-Prokophiev

This letter proposes a generalized stabilizer-oriented design method for grid-forming virtual synchronous generator (GFVSG) attached to weak-stiffness power networks, where a rate of change of frequency feedforward control strategy (RoCoF-FCS) is put forward to improve frequency stability, enhance damping performance, and avoid aperiodic loss of synchronization (ALoS). In addition, the feedback analytical framework, which connects RoCoF and rate of change of voltage (RoCoV), is proposed to identify both wideband oscillation and ALoS. Finally, the proposed method is validated by time-domain simulations.

BACKGROUND: Immediate implant placement to the fresh socket of the extracted tooth, with immediate loading, is well documented. Dental roots in proximity to the vestibular plate require thorough attention from clinicians. Implants placed close to the vestibular plate often lead to its resorption and gingival recession. Therefore, dental surgeons place implants 23 mm away from the vestibular plate. In turn, prosthodontists plan implant placement so that the screw channel is not on the vestibular surface, which is most significant in the aesthetic area. However, this is not always possible, and there is a conflict between implant placement with proper primary stability and its simultaneous loading with a screw-retained crown. AIM: To conduct radiological assessment of the ideal implant placement for a screw-retained crown. MATERIALS AND METHODS: A total of 120 cone-beam computed tomography (CBCT; 3 groups of 40 people with different root positions) were analyzed. In each group, the possibility of extracting tooth 1.1 and inserting an implant was evaluated in compliance with the protocol for immediate implantation and the possibility to have the screw shaft of the artificial crown on the palatal surface. RESULTS: Group C was defined as the most favorable for immediate implant placement with a screw-retained crown. The least favorable was group N. In total, the screw channel in 40% of the cases was located palatally, 26.6% to the incisal edge, and 33.3% on the vestibular surface. CONCLUSIONS: Careful analysis of CBCT when planning implant-supported restoration in the aesthetic area is an integral part of the treatment. A team approach is required from surgeons and prosthodontists when planning. In a larger percentage of cases, implant-supported prosthetics in the maxillary central incisors involve the use of alternative solutions for the restoration of screw-retained crowns.

The research results conducted on binderless tungsten carbide (WC) ceramics obtained by Spark Plasma Sintering (SPS) of WC powders with different average particle sizes (0.095, 0.8, 3 μm) are presented. Nonuniform distribution of crystalline phases and microstructure of the WC ceramics was studied using layer-by-layer XRD analysis and SEM. Surface layers of the WC-based ceramics are characterized by nonuniform distribution of W2C crystalline phase and grain sizes, including the appearance of abnormally large grains. Thickness of the nonuniform layer was at least 50 μm. The effect under study is associated with an intense carbon diffusion from graphite foil. On the one hand, this contributed to a decrease in the intensity of W2C phase particle formation, which is transformed into α-WC phase due to the carbon. On the other hand, it caused abnormal grain growth in the layer where the carbon diffused. The obtained value of the carbon diffusion depth exceeds the values known from the literature (up to 1 μm in the case of volume diffusion even at temperature of 2370℃ and exposure time of ~ 60 h). The use of boron nitride (BN) as a protective coating on graphite mold parts did not prevent the formation of nonuniform layer on the ceramic surface.

This paper investigates the density, phase composition, microstructure and mechanical properties (microhardness, fracture toughness) of binderless WC + SiC ceramics obtained by conventional pressureless sintering (CPS) and Spark Plasma Sintering (SPS). α-WC nanopowders obtained by DC arc plasma chemical synthesis and β-SiC powders have been used as raw materials. The content of SiC particles was 1, 3, 5% wt. Excess graphite (0.3, 0.5% wt.) was added to α-WC nanopowders to decrease the volume fraction of W2C particles that negatively affect the mechanical properties of ceramics. WC + 1% wt. SiC + 0.3% wt. C ceramics are shown to have a homogeneous fine-grained microstructure, high relative density, increased microhardness and Palmquist fracture toughness. The CPS and SPS activation energies of WC + SiC nanopowders at an intensive shrinkage stage are determined using the Young-Cutler model. The effect of carbon and SiC particles on the CPS and SPS activation energies of tungsten carbide nanopowders has been analyzed. The CPS activation energies of WC, WC + C and WC + SiC + C nanopowders are shown to be closer to the carbon diffusion activation energy along α-WC grain boundaries. The SPS activation energies of WC and WC + SiC nanopowders turn out to be lower than the carbon grain boundary diffusion activation energy of α-WC.

Background: Success of immediate implant placement in the area of maxillary central incisor greatly depends on the degree of tightening of the fixing screw of the fully zirconia crowns. For treatment of this kind, clinicians use implants of various designs and implants with angled abutments to bypass anatomical limitations, achieve primary implant stability, and fabricate a screw-retained crown. However, the crown fabricated for the implant placed can experience non-axial loads during occlusion, which can lead to screw loosening and adversely affect treatment success, especially in the early post-operative period. Objective: to perform a comparative analysis of the effect of cyclic loading on the reliability of the fixing screw in full zirconia crowns supported by angled implants with platform inclination of 12, 24, 36, by straight implants and straight implants with angled abutments. Materials and methods: the degree of the prosthetic screw tightening was studied in 30 samples, 6 groups of 5 implants (straight implants, straight implants with standard 17 angled abutments and 12 custom abutments, angled implants with platform inclination of 12, 24, and 36. A full zirconia crown of maxillary central incisor was fabricated and fixed on every implant and subsequently exposed to cyclic loading up to 1*106 cycles. Afterwards, the maximum unscrewing torque was determined for each group. Statistical analysis was carried out. Results: the minimum values of the maximum torque were 20.8040.01 N/cm for the group of straight implants with 17 angled abutments, and the maximum values for the group of straight implants were 22.820.04 N/cm. There was no significant difference in values between the straight and angled implant groups. However, the values in these groups were higher compared to the groups of implants with angled abutments. Conclusion: the study showed that fixing screws are more reliable in crowns supported by straight implants and angled implants with different platform inclinations. Therefore, these implants are the most preferred option for immediate implant placement in the anterior region.

Background. The technique of immediate implant placement and immediate loading after maxillary central incisors extraction is of great importance. According to the literature, implant placement with immediate loading is the most preferred method of treatment in the long term. The anatomical constrictions of the maxilla make implant placement difficult. To achieve primary stability and make a screw-retained crown, dental surgeons are forced to fix the implant placing it towards the palatal wall. When implant placed this way the crown will be bulkier than the one of the extracted tooth. This change in anatomy can lead to patient discomfort and some parafunctions (in speech, chewing, etc.). Objectives. The aim of this study was to assess the potential discomfort in patients with changes in the crown anatomy of maxillary central incisors after implant-supported prosthetics. Materials and methods. 50 students (25 males and 25 females) had intraoral scanning with the 3 Shape scanner. A simulation of a possible increase in the crown volume was carried out in the ExoCAD software at a rate of an implant + titanium base + layer of structural material with zirconium dioxide as an example, on average equal to 3-4 mm. Onlays imitating the increased volume of the crown were milled and fixed in the oral cavity of the subjects on tooth 1.1 with further survey carried out. Results. The survey revealed that crown anatomy change brought some discomfort in the majority of respondents having affected the function of speech production and eating, etc. Conclusion. The data obtained suggest that a change in the anatomical shape of the crown during implant-supported prosthetics can affect vital functions of patients and cause discomfort. More attention should be paid to implant placement planning, taking into account further prosthetics in the aesthetic area. Therefore, it is recommended to use angulated implants as a solution. Key words. Dental implantation, immediate loading, aesthetics, maxillary central incisor, maxillary anatomy, prosthetics, screw retention, angulated implants.

The paper describes the results of fatigue and corrosion-fatigue tests of the pseudo α titanium alloy PT-3V, which is actively used in nuclear engineering for the manufacture of heat exchange equipment for modern nuclear power plants. Alloy PT-3V has an inhomogeneous coarse-crystalline structure with precipitates of β-phase particles along the grain boundaries of the lamellar shape. It is shown that smooth specimens tested according to the bending-with-rotation loading scheme do not show a noticeable decrease in the cyclic fatigue life when exposed to a neutral corrosive environment (3 % aqueous NaCl solution). However, specimens with a notch (stress concentrator) tested according to the cantilever bending loading scheme demonstrate sensitivity to the action of a corrosive environment at the stages of initiation and growth of fatigue cracks, as evidenced by a significant decrease in the number of cycles before crack initiation, as well as before specimen failure, in comparison with tests in air. Fractographic analysis of fractures of smooth specimens and specimens with a concentrator after fatigue and corrosion-fatigue tests has been carried out. The main stages of the initiation and growth of fatigue cracks are revealed. It has been established that a decrease in the resistance to the initiation and propagation of corrosion-fatigue cracks during testing of notched specimens may be due to the effect of hydrogen embrittlement, accelerated by stress concentration.

Numerous epithermal Au–Ag deposits and ore occurrences of the Chukchi Peninsula are localized in the Cretaceous Okhotsk–Chukotka (OCVB) continent-marginal and Late Jurassic–Early Cretaceous Oloi (OVB) island arc volcanic belts and in Early Cretaceous postcollisional volcanic troughs. Volcanotectonic depressions, calderas, and volcanic domes control the location of the deposits. The orebodies of the deposits are quartz–adularia veins, sometimes en-echelon ones forming extending vein zones, as well as isometric and linear stockworks. The auriferous veins of most deposits display complex breccia–crustification structures. The vein ores have rhythmically and colloform–banded structures, with a predominantly fine distribution of ore mineral grains, often with banded clusters of ore minerals (ginguro). Native gold is of low fineness; the dispersion of this index varies from low to high. Acanthite is widespread in the ores. Its highest contents are specific to deposits with the repeated redistribution of substance (Kupol, Corrida, and Valunistoe). Based on the results of mineralogical studies, most of the epithermal Au–Ag deposits of the Chukchi Peninsula can be assigned to the Se type. The ores of some deposits (Valunistoe, Dvoinoe, etc.) contain both Se and Te minerals. The telluride-richest sites of the Sentyabr’skoe and Televeem deposits are far from the main orebodies. Most of the Chukchi epithermal Au–Ag deposits have many common characteristics (low and moderate temperatures of fluids, low fluid salinity, domination of carbon dioxide over methane, etc.) typical of low-sulfidation deposits. The maximum temperatures and salinity are specific to fluids in the Central Chukchi sector of the OCVB and in the Baimka zone of the OVB, and the minimum ones are typical of fluids in the East Chukchi flank zone and inner zone of the OCVB. The average salinity of mineral-forming fluids in the inner zone of the OCVB is half as high as the salinity of fluids in the East Chukchi flank zone of this belt, although the sulfate content is higher. At the same time, the fluids in the inner zone of the OCVB are richer in carbon dioxide and bicarbonate ion than the fluids in the East Chukchi flank zone of this belt. The fluid inclusion data permit the Vesennee deposit (Baimka zone) to be regarded as an intermediate-sulfidation one and suggest the presence of epithermal high-sulfidation deposits in the inner zone of the OCVB.

Aim. The goal of the study was to analyze the differential expression of lipid metabolism-related genes in the atherosclerotic plaques of different types in patients with coronary atherosclerosis.Material and Methods. The study was performed on the specimens of atherosclerotic plaques in 45–65-year-old patients with coronary atherosclerosis with stable exertional angina functional class II-IV without acute coronary syndrome. Coronary atherosclerosis was verified by coronary angiography. Atherosclerotic plaque tissue was sampled intraoperatively when indicated. Whole-genome sequencing of ribonucleic acid (RNA) was performed using the TruSeq RNA Sample Preparation Kit (Illumina, USA).Results. We analyzed the differences in the expression of 12 genes including LDLR, APOB, PCSK9, LDLRAP1, LIPA, STAP1, ABCA1, APOA1, APOE, LPL, SCARB1, and SREBF2 depending on the type of atherosclerotic plaques. The expression level of APOE gene was eight times higher in unstable atherosclerotic plaques of dystrophic-necrotic type (p < 0.0001). The expression levels of LDLR and APOB genes were eight times higher in stable atherosclerotic plaques (p < 0.0001). We did not find differences in the expression levels of the ABCG5, ABCG8, APOC3, CETP, CLPS, CYP7A1, and PNPLA5 genes.Conclusion. The study showed the differences in the activity of individual metabolism-related genes in the atherosclerotic plaques of different types in patients with coronary atherosclerosis. Obtained data may become the basis for the development of test systems aimed at predicting the development of atherosclerotic process and its complications.

Unalloyed titanium VT10 with a record value of the ultimate tensile strength of 1350 MPa obtained using technologies of selective laser melting and rotary swaging. This value exceeds by 3 times the tensile strength of commercially pure titanium produced using conventional technologies and also exceeds the strength values of Ti6Al4V (grade 5) high strength titanium alloy. The reasons of the increase in the strength characteristics of titanium VT10 are the finedispersed marten site obtained due to high crystallization rates in the process of selective laser melting, and its additional refinement during the rotary swaging process. To study the thermal stability of the mechanical properties of titanium VT10 processed using various technologies, research of the effect of annealing temperature in the range of 100–800 °C on the ultimate tensile strength and elongation to failure were carried out. Results have shown that the dependence of the ultimate tensile strength on the annealing temperature for VT10 titanium samples after selective laser melting and rotary swaging has a threestage behavior. The ultimate tensile strength decrease by 25–35% after heat treatment at 800 °C. The values of elongation to failure for VT10 titanium samples processed by selective laser melting and rotary swaging monotonically increase from 8–12 to 18–23% when the annealing temperature grows up to 800 °C. The possibilities of methods of selective laser melting, rotary swaging and heat treatment to control the mechanical characteristics of titanium VT10, which is a promising material for the manufacture of osteointegrable medical implants, are demonstrated. The combined application of the abovementioned methods makes it possible to produce VT10 titanium with a given combination of strength and plastic characteristics in a wide range of values.

Submicron-grade powders of Na1-xZr2(PO4)3-x(XO4)x compounds (hereafter referred to as NZP) and Ca1-xZr2(PO4)3-x(XO4)x compounds (hereafter, CZP), X = Mo, W (0 ≤ x ≤ 0.5) were obtained by sol-gel synthesis. The compounds obtained were studied by X-ray diffraction phase analysis and electron microscopy. An increase in the W or Mo contents was shown to result in an increase in the unit cell volume of the NZP and CZP crystal lattices and in a decrease in the coherent scattering region sizes. Thermal expansion behavior at high temperatures of synthesized NZP and CZP compounds has been investigated. The dependencies of the parameters a and c on the heating temperature, as well as the temperature dependence of the crystal lattice unit cell volume V in the range from the room temperature up to 800 °C, were obtained. The dependencies of the average thermal expansion coefficient (αav) and of the volume coefficient (β) on the W and Mo contents in the compositions of NZP and CZP compounds were studied. Ceramics Na1-xZr2(PO4)3-x(XO4)x with relatively high density (more than 97.5%) were produced by spark plasma sintering (SPS). The increase in the W or Mo contents in the ceramics leads to an increase in the relative density of NZP and to a decrease of the optimum sintering temperature. The mean grain size in the NZP ceramics decreases with increasing W or Mo contents. The study of strength characteristics has revealed that the hardness of the NZP ceramics is greater than 5 GPa, and that the minimum fracture toughness factor was 1 MPa·m1/2.

The ceramic samples fabricated by spark plasma sintering of powder mixtures based on silicon nitride (Si3N4) were investigated. The powder mixtures were made by wet chemical methods from commercial α-Si3N4 powder (the particle size

The structure, microstructure, coefficient of thermal expansion (CTE), and mechanical properties of Na1+2xZr2−xCox(PO4)3 ceramics (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) were studied. Na1+2xZr2−xCox(PO4)3 submicron powders with the NaZr2(PO4)3 structure (NZP, kosnarite type) were obtained by the solid-phase method. The starting reagents (NaNO3, ZrOCl2·8H2O, NH4H2PO4, CoCl2·6H2O, ethanol) were mixed with the addition of ethyl alcohol. The resulting mixtures were annealed at 600 °C (20 h) and 700 °C (20 h). The obtained phosphates crystallized in the expected structure of the NaZr2(PO4)3 type (trigonal system, space group R3¯c). Thermal expansion of the powders was studied with high-temperature X-ray diffraction at temperatures ranging from 25 to 700 °C. CTEs were calculated, and their dependence on the cobalt content was analyzed. Na1+2xZr2−xCox(PO4)3 ceramics with high relative density (93.67–99.70%) were obtained by Spark Plasma Sintering (SPS). Ceramics poor in cobalt (x = 0.1) were found to have a high relative density (98.87%) and a uniform fine-grained microstructure with a grain size of 0.5–1 µm. Bigger cobalt content leads to a smaller relative density of ceramics. During the sintering of ceramics with high cobalt content, anomalous grain growth was observed. The powder compaction rate was shown to be determined by creep and diffusion intensity in the Na1+2xZr2−xCox(PO4)3 crystal lattice. SPS activation energy in ceramics increased as the cobalt content grew. The microhardness and fracture toughness of ceramics did not depend on their cobalt content.

International audience; Mini-EUSO is a high-sensitivity imaging telescope that observes the Earth from the ISS in the near ultraviolet band (290÷ 430 nm), through the nadir-facing, UV-transparent window in the Russian Zvezda module. The instrument, launched in 2019, has a field of view of 44∘, a spatial resolution on the Earth’s surface of 6.3 km and a temporal sampling rate of 2.5 microseconds. Thanks to its triggering and on-board processing, the telescope is capable of detecting UV emissions of cosmic, atmospheric, and terrestrial origin on different time scales, from a few microseconds up to tens of milliseconds. The optics is composed of two Fresnel lenses focusing light onto an array of 36 Hamamatsu Multi-Anode PhotoMultiplier Tubes, for a total of 2304 pixels. The telescope also contains two cameras in the near-infrared and visible, an 8-by-8 array of Silicon-PhotoMultipliers and a series of UV sensors to manage night-day transitions. The scientific objectives range from the observation of atmospheric phenomena [lightning, Transient Luminous Events (TLEs), ELVES], the study of meteoroids, the search of interstellar meteoroids and strange quark matter, mapping of the Earth’s nocturnal emissions in the ultraviolet range, and the search of cosmic rays with energy above 1021 eV. The instrument has been integrated and qualified in 2019, with the final tests in Baikonur prior to its launch. Operations involve periodic installation in the Zvezda module of the station with observations during the crew night time, with periodic downlink of data samples, with the full data being sent to the ground via pouches containing the data disks. Mission planning involves the selection of the optimal orbits to maximize the scientific return of the instrument. In this work, we will describe the various phases of construction, testing, and qualification prior to the launch and the in-flight operations of the instrument on board the ISS.