Search

Introduction. The issues of dynamic and functional anatomy of the neck are of considerable practical and theoretical interest. This is due to the peculiarities of the displacement of the musculofascial layers when changing the position of the head in space, the description of which presents significant difficulties. Particular practical importance has therefore the study of dynamic phenomena of this area as well as the analysis of morphological and biomechanical changes leading to the development of somatic dysfunction of the neck. Aim. Based on the topographic and anatomical studies, as well as with the help of finite element modeling, to study the patterns of displacement of the muscular-fascial layers of the neck when turning the head by 20º and 50º. Materials and methods. The topographic and anatomical study used the results of 18 MRIs, the analysis of which was carried out using the Vidar Dicom Viewer software. To build a finite element model, data from a CT study of a patient were used, which has not any pathological changes in the organs and musculoskeletal system of the neck. As a result of the subsequent processing of the CT study data, a personalized anthropomorphic finite element model of the neck region was constructed, with the help of which a series of virtual topographic and anatomical studies were performed, repeating in general terms the topographic and anatomical part of the work. Results. 1. The values of rotational and angular displacement of all fascia of the neck are nonlinear. 2. The fascia of the neck are displaced relative to each other when turning the head due to the difference in the values of angular displacement. 3. The magnitude of the angular displacement of the 2nd fascia of the neck at the level C2-C3, C3-C4 and C4-C5 when turning the head 20º, as well as at the level C4-C5 when turning the head 50º exceeds the value of the angle of rotation of the head relative to the trunk. 4. The direction of rotational and angular displacement for all fasciae at the level C6-C7 corresponds to the direction of rotation of the head, with the exception of the dorsal part of the 4th fascia of the neck, which at this level, together with the esophagus, shifts in the opposite direction relative to the axis of symmetry. 5. Fasciae located at a greater distance from the center of the intervertebral disc are characterized by large values of angular and rotational displacement. 6. The rate of change in the ratio of rotational and angular displacements is higher at the level of the lower segments. 7. The results of measurements of the rotational displacement of the fascial layers of the anthropomorphic finite element model demonstrate a positive correlation with the data of the topographic and anatomical study. Conclusion. The patterns of displacement of the neck musculofacial layers should be taken into account when modeling somatic dysfunction of the neck, as well as in the process of diagnosis and planning of osteopathic effects.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a structurally diverse group of drugs with a common mechanism of action (reversible inhibition of cyclooxygenase). They are widely used due to their analgesic, antipyretic and anti-inflammatory properties; available both as prescription and over-the-counter medications; available as individual pharmaceuticals, compound painkillers. The methods of treatment of acute and chronic pain are different. For acute pain, analgesics such as nonsteroidal anti-inflammatory drugs and opiates are commonly used, sometimes in combination with regional anesthesia such as peripheral nerve blockade or peridural local anesthesia. A systematic review and meta-analysis of the efficacy and safety of nimesulide published in the sources MEDLINE/PubMed, Embase, Cochrane Library and China National Knowledge Infrastructure. The efficacy and safety of the use of nimesulide in clinical practice is shown. In particular, in the treatment of acute musculoskeletal pain (dorsopathy of the cervical-thoracic and lumbar region), as well as migraines, due to a decrease in the release of calcitonin- gene related peptide (CGRP) and prostaglandin E2 (PGE2) from the trigeminal ganglia, while other NSAIDs have shown a lack of efficacy. Noncompliance with international guidelines, irrational use of NSAIDs among all groups of drugs is one of the leading causes of hospitalizations associated with side effects, which increases health care costs. The article presents an overview of the safety and efficacy of medicines containing nimesulide, as well as recommendations for patients and prescribers of this drug.

Rationale: 3D modeling of various anatomical structures has recently become a separate area of topographical, anatomical, and biomechanical studies. Current in vivo visualization methods and quantitative analysis in silico allow to perform the precise modeling of these processes aimed at investigation into the pathophysiology of cardiovascular disorders, risk prediction, planning of surgical interventions and virtual refinement of their separate stages.Aim: To develop tools for elaboration, analysis and validation of personalized models of various structures of the heart and aortal arch taking into account their morphological characteristics.Materials and methods: We used the results of 14 computed tomography studies from randomized patients without any disease or anomaly of the heart, aortic valve and aortal bulb. The analysis and subsequent transformation of the images were done with Vidar DICOM Viewer, SolidWorks 2016, VMTKLab software. For the FSI modeling of the aortic arch based on the results of functional multiaxial computed (MAC) coronarography (a female patient of 55 years) we developed a personalized model of the ascending aorta and aortic arch at the beginning of the systole. Using HyperMesh software (Altair Engineering Inc., USA) we have built a network of finite element of the luminal area, adventitia, and aortic media. To model mechanical properties of the aortic structures we used an anisotropic hyperelastic material model by Holzapfel – Gasser – Ogden. Material modeling, choice of the limiting antecedents, and analysis of fluid-structure interaction were performed with Abaqus CAE 6.14 software (Simulia, Johnston, USA). Adaptive image meshing by Young was used to elaborate the finite element template of the left ventricle. The algorithm was realized within the IDE PyCharm software media in Python 3.7. The algorithm was realized based on the open-source libraries OpenCV, NumPy, Matplotlib, and SciPy.Results: The first stage of the development of the aortic valve model included the design of its virtual 3D template. Thereafter, a cohesive geometric model was elaborated. Subsequent stage of the work included the transformation of the aortic valve geometric model into the parametric one. This was done through the use of the “Equations” tool within the SolidWorks. No problems with geometry of the model during its deformation were identified. Aortic segment modeling was based on the data obtained by functional MAC coronarography. Based on this and on Inobitec Dicom Viewer software, we generated a multiplane reconstruction of the zone of interest including anatomical structure of the heart and aortic valve. With the resulting set of contours, we created a 3D model, which then was converted into a polygonal stereolithographic model. We developed an algorithm for adaptive meshing to elaborate a polygonal template capable of deformation that can be used for registration both with the net methods (B-Spline) and based on the image characteristics (homologous pixels). Conclusion: The resulting parametric 3D model of the aortic valve anatomical structures is capable of adequate transformation of its geometry under external factors. It can be used in simulators of endovascular cardiosurgical procedures.

The paper presents the adhesive strength measurements of the Ni–Cu surface alloy formed on a copper substrate at a different thickness of the transition layer. The formation of the surface alloy is provided by the low-energy high-current electron beam of a microsecond duration; the different thickness of the transition layer is varied by the thickness of the nickel film sputtered. The multiple deposition-irradiation process is performed during one vacuum cycle. It is found that the cross-section of the film (Ni)-substrate (Cu) interface is rather developed and curved. The transition layer thickness reduces with increasing thickness of the deposited nickel film. Scratch testing shows that the adhesive strength of the Ni–Cu surface alloy obtained by using the low-energy high-current electron beam, is higher than that of the sputter-deposited surface alloy. The highest adhesion is observed for the Ni–Cu surface alloy obtained by the nickel film deposition 0.125 μm thick. In this case, the crack formation and localized film delamination occur under the critical loads of 15 and 17 N, respectively. Nevertheless, a complete delamination of the surface alloy is not observed.

Objective. To conduct a comparative analysis of the clinical efficacy of cholinergic drugs and acetylcholinesterase inhibitors and their combinations in the complex therapy of cerebrovascular pathology and the sequelae of closed craniocerebral trauma (cCCT) using clinical, instrumented, and laboratory follow-up investigations. Materials and methods. A total of 90 patients with cerebrovascular pathology (chronic cerebral ischemia grade 2 (I67; 45 patients) and the sequelae of cCCT (T90; 45 patients) were studied. Groups were divided into three subgroups each of 15 patients. Complex treatment included basal and specific therapy: subgroup 1 received the drug Neuromidin, group 2 received Gliatilin, and group 3 received Neuromidin plus Gliatilin. Treatment duration was two months. All patients underwent complex clinical, neurophysiological, and laboratory investigations before treatment and at one and two months from treatment initiation: plasma cholinesterase activity was estimated, patients were tested on the Mini Mental State Examination (MMSE) and the Hamilton scale, and patients underwent transcranial magnetic stimulation with assessment of the central motor conduction time and evaluation of somatosensory evoked potentials with determination of the central afferent conduction time. Results. Before treatment, a strong positive correlational relationship was found between patients’ age and serum cholinesterase activity (Rs = 0.77; p = 0.0001). On the background of treatment, all study parameters showed significant (p < 0.05) improvements with the exception of the MMSE, which showed only a trend to improvement) in subgroups 1 and 3 of each group as compared with values obtained in subgroups 2 of the corresponding groups. In addition, at two months from treatment initiation, there were significant decreases in serum cholinesterase activity in patients of subgroups 1 and 2. Conclusions. Assessment of deviations in the “cholinergic profile” (blood cholinesterase activity) in patients with cerebral pathology and the strategy of using cholinergic drugs and acetylcholinesterase inhibitors and their combination to correct psychoneurological disorders is among the most important directions in optimizing the combined treatment of patients of this category.

The structural features of the surface of a TiNi-based powder alloy produced by diffusion sintering are studied. Two-dimensional porous samples based on a TiNi powder alloy are manufactured for the experimental investigation of their structural features by the methods of non-destructive testing. It is determined that the phase composition of the TiNi-based powder alloy is represented by the TiNi (B2) austenitic phase and precipitates of the secondary phases enriched with nickel – Ti3Ni4 and titanium – Ti2Ni. The chemical compositions of the TiNi compound and the Ti2Ni secondary-phase particles are determined. A three-dimensional reconstruction of the surface of the TiNi-based powder alloy is performed by optical profilometry. It is shown that, depending on the sintering temperature regime and particle size distribution of the TiNi powder, it is possible to obtain a developed rough surface with a roughness coefficient within Ra = 64–87 μm. An analysis of the surface microstructure of the resulting material indicates the existence of several types of terraced relief — hexagonal islands of regular shape 5–10 μm and large terraced structures up to 30– 40 μm in size.

Results of investigations of acoustic signals induced in a copper plate irradiated with a microsecond lowenergy high-current electron beam (LEHCEB) are presented. The characteristic acoustic signal waveforms, their amplitudes, phases, and frequencies are experimentally measured. It has been established that the acoustic signals induced by LEHCEB irradiation have groups of characteristic spectral components with fundamental frequencies of 6, 11, 22–24, 80, and 100–120 kHz whose amplitudes increased with charging voltage. It has been established that from the change of the 80 kHz harmonic with the charging voltage, the beginning of LEHCEB generation, its stable or unstable phase, and the beginning of target melting can be traced. It has been found that for a fixed charging voltage of each pulse in a series, the amplitude and phase-frequency structure of acoustic signals are almost the same.

This study presents the results of studying the microstructure and topological short-range atomic order in an amorphous Ti−Ni−Тa−Zr-based surface alloy formed by the additive method through pulsed electron-beam liquid-phase mixing of the “Ti70Ta30 film (50 nm)/Zr film (100 nm)/TiNi substrate” system. It is shown that an amorphous structure with a thickness of 2 μm is formed in the cross-section of the surface alloy and is characterized by the gradient chemical composition. It is found that the transition sublayer adjacent to the TiNi substrate has a nanocomposite crystalline structure based on the Ti2Ni intermetallic compound. By means of the atomic radial distribution function method, using electron nanobeam diffraction data, a study of the topological short-range atomic order in the amorphous layer is performed. It is shown that the atomic structure in the amorphous surface Ti−Ni−Тa−Zr alloy has a cluster structure which can be described by the superposition of coordination polyhedra interconnected with each other by common faces corresponding to the different crystalline devitrification phases.

The paper presents research results of the synthesis of Ni–Al surface alloy performed in a single vacuum cycle via magnetron sputtering of Ni (0.5 μm)–Al (1.5 μm)–Ni (0.5 μm) composite coating onto a steel substrate and its successive single pulse irradiation with low-energy, high-current electron beam (LEHCEB) of a microsecond duration. The numerical solution of the heat equation is used to determine the optimum LEHCEB modes which provide melting of all the films deposited. It is shown that the single pulse irradiation of thin films leads to the formation of the surface alloy consisting mainly of high-melting-point NiAl intermetallic phase. The structure of the surface alloy is a 2 μm thick homogeneous coating with 2×4 μm globules beneath separated by a thin layer of the substrate material. It is found that the wear resistance of the obtained Ni–Al surface layer is 2.7 times higher than that of the untreated steel substrate.

The study of the influence of electron-beam treatment on the structural features of a TiNi powder alloy obtained by calcium-hydride reduction is carried out. It is found that electron-beam treatment leads to homogenization of the phase and chemical composition of the surface layer of the TiNi powder alloy, smoothing of the surface relief of TiNi powder particles, and the healing of the defects on their surface. It is shown by energy dispersive X-ray spectral microanalysis that the concentration of Ti in the surface layer increases. This is due to recrystallization of this layer containing Ti2Ni particles during its remelting under the influence of the high energy density of the electron beam during treatment.

This work comprises a study of the effect of silicon on the topographical parameters and mechanical properties of the Ti-Ni-Ta-Si surface alloy (SA) synthesized on the NiTi-substrates by the additive thin-film electron-beam method. It was found that the roughness of [Ti-Ni-Ta-Si]SA (~0.095 μm) has a lower value than in [Ti-Ni-Ta]SA (~0.195 μm). The values of the yield strength σ y in the surface layers of [Ti-Ni-Ta-Si]SA and [Ti-Ni-Ta]SA are characterized by a gradient decrease from ~4.2 GPa up to ~1.2 and ~1.7 GPa, respectively. During the indentation, evaluation of the deformation behavior (recovered elastic –ε elast , and superelastic – εin the surface layers of SE , residual plastic – ε elast deformation) showed, that in surface layers of [Ti-Ni-Ta-Si]SA and [Ti-Ni-Ta]SA due to an increase of ε elast , there was a decrease in ε SE up to ~35 and ~22%, respectively (for the NiTi-initial ε SE ≈ 38%).

The results of numerical and experimental studies on the synthesis of a Ni-Al surface alloy on a steel substrate are presented. The alloy was formed by the preliminary magnetron sputtering of the multilayer Ni-Al coatings of two types, consisting of thin (type I) ∼ 0.1 and thick (type II) $\sim 1\ \mu\mathrm{m}$ films, followed by their irradiation and mixing with a pulsed electron beam transported to the samples in a plasma-filled diode. In the work, the optimal irradiation mode was determined by the numerical method of forming the Ni-Al surface alloy, in which intense melting of all deposited films occurs, and there is no evaporation of the surface material. It is experimentally shown that the Ni-Al surface alloy, which is represented by NiAl high-temperature intermetallic phase, is formed by pulsed electron-beam melting. For the Ni-Al multilayer system consisting of thin films, the surface alloy formed is homogeneous, but a network of cracks appears on the surface. For the Ni-Al multilayer system consisting of thick films, the surface alloy formed is heterogeneous, both along the surface and along the depth of the target. Its structure is a composite that combines the alternation of hard (but brittle) and soft (but ductile) components corresponding to NiAl high-temperature intermetallic phase and (Al, Ni, Fe) solid solution, respectively. Such a structure of the Ni-Al surface alloy makes it possible to obtain a crack-free surface with high tribological and high-temperature corrosion properties.

The study of the surface alloy NiAl formed by irradiating a three-layer system of alternating layers of Ni and Al with a total thickness of 2.5 µm by a low-energy high-current electron beam with a different number of pulses is presented. The influence of the number of irradiation pulses on the morphology of the obtained surface alloys, their microhardness, and the structure of the transition layer on transverse sections is studied. It is found that with an increase in momentum the surface layer becomes smooth and cracks are reduced to a certain number of pulses. The microhardness values of the surface alloys obtained are close and, on average, 1.5 times higher than that of the initial sample.

The synthesis of the surface Ni-Al alloy on a steel substrate is numerically studied. Surface alloys have a significant advantage over coatings since they provide the highest level of adhesion. Heat resistant alloys based on nickel-aluminum are widely used in engineering due to their low density, combination of high thermal conductivity and fracture strength at high temperatures. The application of the Ni and Al multilayer structure for the formation of the surface Ni-Al alloy by the method of liquid-phase mixing is studied. The effect of geometry parameters such as thicknesses of layers is considered. At a certain ratio of effective layer thicknesses the melting threshold of the multilayer structure is minimal.

The paper presents research results into the microstructure of Cu–Cr composite material affected by the highcurrent vacuum arc. The investigation of the electrode cross-sections allows us to emphasize two zones both for anode and cathode: 1) the exposure zone of the vacuum arc and 2) the virgin material. The first zone locates on the surface of electrodes and is just a zone that crystallizes after the electrode melting due to the exposure to the high-current vacuum arc. It is interesting that on anode there appears a narrow, transition layer enriched with chromium nearby the virgin material and with copper in the exposure zone of the vacuum arc. The formation of such a layer on cathode is not observed.

The paper investigates the regularities of the formation of Cr-Zr surface alloy using a low-energy high-current electron beam (LEHCEB). The influence of the electron-beam processing parameters and the magnetron deposition parameters on the elemental composition of the formed Cr-Zr surface alloy is estimated. It is shown that, for all considered modes, there is a general tendency to a decrease in the chromium content in the surface alloy with an increase in the energy density or the LEHCEB processing pulse number. The thickness increasement of the chromium film applied in one cycle or the surface alloy total thickness increasement leads to an increase in the chromium content in the surface alloy. The LEHCEB processing parameters, namely the energy density and the number of pulses, have a greater effect on the chromium content during the formation of the Cr-Zr surface alloy in comparison to the magnetron sputtering parameters, namely the deposited film thickness and the formed surface alloy thickness. A linear regression model that describes the chromium content in the surface alloy depending on the film thickness, the surface alloy total thickness, the number of pulses and the pulse energy density is proposed.

The paper presents the results of numerical simulation of the distribution of thermal fields during the formation of Cr-Zr surface alloy using a pulsed low-energy high-current electron beam (LEHCEB). The melting thresholds of the Cr-Zr system for different thicknesses of Cr films were calculated. The melting threshold of the Cr-Zr system increases linearly with increasing Cr film thickness. A linear regression dependency model of the melting threshold on the film thickness is proposed. Evaporation thresholds of the Cr-Zr system for different thicknesses of Cr films were calculated. The evaporation threshold of the Cr-Zr system increases linearly with increasing Cr film thickness. A linear regression dependency model of the evaporation threshold on the film thickness is proposed. The value of the LEHCEB energy density at which the lifetime of the film and substrate are equal is calculated. This value is a maximum value for the effective formation of Cr-Zr. A model of the LEHCEB energy density, at which the lifetime of the film and the substrate are equal, in the form of a third-degree polynomial is proposed.

The paper deals with the formation of the stainless steel-copper surface alloy which occurs during the single vacuum cycle. Deposition of the stainless steel film onto a copper substrate is performed via successive magnetron sputtering followed by its liquid-phase mixing with copper using the low-energy, high-current electron beam of microsecond length. Numerical calculations are used to identify the optimum irradiation modes for the surface alloying. It is found that the optimum irradiation modes provide the homogeneous surface alloying, and the copper concentration in the obtained layer increases with the increase in energy density of the low-energy, high-current electron beam. The formation of the stainless steel-copper surface alloy increases the wear resistance of copper specimens by 7.5 times as compared to the original specimens. In addition, it is ascertained that the wear resistance of the surface alloy exceeds that of the common film coating (1 μm) more than 5 times.

An important factor limiting the wide application of thin-film metallic glass (TFMG) coatings for improving the surface-sensitive properties of structural alloys is the poor adhesion of TFMG to substrates. This problem can be overcome through the synthesis of MG surface alloys (MGSAs) by additive pulsed electron-beam melting of film/substrate systems of high glass-forming ability. In this work, this approach is applied to the [film (Ti60Ta30Si10, at.%, 100 nm)/substrate (TiNi alloy)] system using a low-energy, high-current electron beam (~2.5 μs, ~15 keV, 1.7 J/cm2) at 10 synthesis cycles and 10 pulses per cycle. Using SEM/WDS, XRD and cross-sectional HRTEM/EDS/SAED analyses it has been found that ~1.5 μm thick SA has completely MG structure, in which the near-surface ~500 nm thick Ni-depleted layer has composition ~Ti56Ta23Ni11Si10. Beneath the MGSA, the ~200 nm thick nanocomposite Ti50Ni30÷40(Ta + Si)20÷10 sublayer, consisting of Ti2Ni nanograins embedded in the amorphous phase is formed. The nanocomposite sublayer is followed by the intermediate sublayer with the eutectic columnar nano-grain B2-structure, which provides the diffusion bonding of MGSA with unmelted TiNi substrate. The monotonic depth dependences of hardness, elastic modulus, depth recovery ratio and plasticity, obtained by indentation, indicate the mechanical compatibility of the MGSA and underlying sublayers with the TiNi substrate. The adhesion-related failure of the MGSA during scratch testing proceeds in the ductile mode mainly through the plastic flow of intermediate sublayer. Evaluation of shape memory effect and superelasticity by torsional deformation technique has shown that synthesis of the MGSA results in an almost 2-fold increase in the martensitic shear stress and significant decrease in the stress hysteresis width compared with the untreated TiNi samples. The irreversible residual strain is ~0.8% at a maximum strain of 6%. Potentiodynamic polarization measurements have shown that synthesis of the MGSA results in the significant enhancement in corrosion resistance of test samples in the Lock-Ringer salt solution.

An important factor limiting the wide application of magnetron-sputtered amorphous or nanocomposite thin-film coatings for improving surface-sensitive properties of structural alloys is the poor adhesion of coating to substrate. This problem can be overcome through the synthesis of surface alloys (SAs) by additive pulsed electron-beam melting of film/substrate systems of high glass-forming ability (GFA). In this work, this approach is applied to the “film (Ti85/70Nb15/30, at.%), 100 nm/substrate (TiNi SMA)” system using low-energy, high-current electron beam (~2.5 μs, ~15 keV, 1.7 J/cm2) at 10 synthesis cycles and 10 pulses per cycle. The melting/solidification conditions were evaluated using numerical modeling of pulsed heating, taking into account the formation of eutectic in the Ti-Ni-Nb system and initial temperature risen up to 473 K to the end of the synthesis. Using surface SEM/EDS, AES, XRD and cross-sectional HRTEM/EDS/SAED analyses it has been found that both SAs of thickness ~1.5–2 μm have depth-graded structure, in which outer Ni-depleted layer is the multiphase nanocomposite with quasicrystals followed by predominantly Ti-Ni-based amorphous sublayer. Beneath, the ~1 μm thick intermediate sublayer with eutectic columnar structures (B2 + Ti2Ni and B2 + Ti3Ni4 for first and second SA, correspondently), monotonic Nb substitution for Ni and diffusion transition to TiNi substrate is formed. Depth-graded structure of modified surface layers provides monotonic changes with depth in nanohardness, elastic modulus, depth recovery ratio and plasticity to the values of the TiNi substrate. For both SAs the evolution of structure in depth is in a reasonable agreement with glass forming composition range evaluated for Ti-Ni-Nb system using Miedema's model.

A Cr-Cu surface alloy is synthesized using successive operations of Cr film deposition followed by mixing in a melted phase with the Cu substrate by a low-energy, high-current electron beam (LEHCEB). The parameters of LEHCEB are as follows: electron energy 20–30 keV and pulse duration 2–4 μs. Depending on the LEHCEB energy density, the concentration of Cr in the alloy is in the range from 60 to 20 at.%. The alloy microstructure has been analyzed, and its morphology is shown to represent nanosized chromium particles measuring 10–30 nm uniformly distributed in the copper matrix. The synthesized Cr-Cu surface alloys demonstrate a more than a factor of 3 a decrease in wear coefficient, which is nearly as low as the wear coefficient of Cr coatings. Some defects such as networks of cracks and pores, are observed in the lengthy regions of chromium. They are attributed to the tensile thermal stresses taking place during solidified melt cooling due to a large difference between the thermal expansion coefficients of copper and chromium. Keywords: Surface alloy, Cr-Cu alloy, Pulsed electron beam, Wear resistance, Nanostructuring

In this work a silver-brass surface alloy was produced directly on brass microelectronics parts in vacuum by alternating processes of Ag thin film deposition followed by a pulsed electron-beam mixing of deposited film and a top layer of the substrate without breaking vacuum. Thickness of produced surface alloy was ranging from 7 to $17\ \boldsymbol{\mu} \mathbf{m}$ . Investigation of cross-section of samples with formed silver-brass surface alloy revealed that the surface layer is divided by two zones of pure Ag followed by transition layer where the concentration of Ag drops from 100 to 0%. The investigation of adhesion properties of three types of coatings (1) silver-brass surface alloy, (2) Ag coating deposited by electroplating, and (3) Ag coating deposited by magnetron sputtering have been fulfilled. This investigation revealed the best adhesion properties for silver-brass surface alloy. Amplitude-frequency characteristics for different types of silver coatings have been measured.

Chromium-copper surface alloy was produced directly on the Cu electrodes in vacuum by alternating processes of Cr-Cu thin film deposition followed by a pulsed electron-beam mixing in melted phase of deposited films and a top layer of the substrate. Composition of produced surface alloy was ranging from 30 to 50 wt.% of Cr and from 70 to 50 wt.% of Cu, respectively. The thickness of produced Cr-Cu surface alloys was in the range $5-10\ \boldsymbol{\mu}\mathbf{m}$ . It was established that produced Cr-Cu surface alloy consists of the very small-size particles of Cr of ∼ 10 nm in diameter embedded into Cu matrix. High-voltage hold-off measurements showed an increased value of breakdown electric fields for the synthesized Cr-Cu surface alloy compared to a Cr-Cu alloy produced by conventional powder metallurgy method. Tribological tests demonstrated 5-times increase in wear resistance of synthesized Cr-Cu surface alloy compared to a Cr-Cu alloy produced by conventional method.

The paper presents results on optimizing the MOVPE technology of light-emitting diode (LED) structures in a Dragon-125 system to accelerate the technological cycle. Due to the high growth rate of GaN layers and optimization of the initial GaN growth phase, the total duration of the epitaxial process is reduced from 4 h 45 min to 2 h 44 min. The LED diode structures grown by this technique compare well in quality with LEDs grown by the standard method in the commercially available AIX2000HT system.

A comparative analysis of the clinical efficacy of cholinergic drugs and acetylcholinesterase inhibitors (IHE), as well as their combination, in the treatment of cerebrovascular disease and consequences of intracranial injury according to clinical, instrumental and laboratory dynamic observations.Ninety patients with cerebrovascular pathology, including 45 with chronic brain ischemia stage 2 (ICD-10 I67) and 45 with sequelae of intracranial injury (ICD-10 T90.5), were enrolled in the study. Complex treatment of patients included basic and specific therapy. The groups were divided into 3 subgroups of 15 people: the neuromidin group, the gliatilin group and the neuromidin + gliatilin group. The duration of treatment was 2 months. All patients underwent a comprehensive clinical, neurophysiological and laboratory examination prior to therapy, after 1 month and 2 month from the beginning of therapy: a study of cholinesterase activity in the blood, testing on MMSE and Hamilton scales, transcranial magnetic stimulation with determination of Central motor conduction time and somatosensory evoked potentials with calculation of Central afferent conduction time.Prior to treatment, a significant positive strong correlation was found between the age of patients and the level of CE activity in serum (Rs=0.77; p=0.0001). The treatment resulted in a significant (p0.05) improvement of all parameters (except for MMSE that showed a trend towards improvement) in the neuromidin and the neuromidin + gliatilin subgroups of each group compared to those in the gliatilin subgroups. In addition, after 2 months from the beginning of treatment, there was a significant decrease in the activity of CE in serum in the neuromidin and the neuromidin + gliatilin subgroups.The study of deviations of the 'cholinergic profile' (the level of CE activity in the blood) in patients with cerebral pathology and the strategy using cholinergic drugs, IHE and their combination for the treatment of neuropsychiatric disorders, is one of the important directions in the optimization of combined therapy of patients of this profile.Цель исследования. Сравнительный анализ клинической эффективности холинергических препаратов и ингибиторов ацетилхолинэстеразы, а также их сочетания в комплексной терапии цереброваскулярной патологии и последствий закрытых черепно-мозговых травм (ЗЧМТ) по данным клинико-инструментального и лабораторного динамического наблюдения. Материал и методы. Обследованы 90 пациентов с цереброваскулярной патологией (хроническая ишемия мозга 2-й стадии (I67; 45 пациентов) и последствиями ЗЧМТ (T90.5; 45 пациентов). Группы были разделены на 3 подгруппы по 15 человек. Комплексное лечение больных включало базисную и специфическую терапию: в 1-й подгруппе - лекарственный препарат (ЛП) Нейромидин, во 2-й - ЛП Глиатилин, в 3-й - ЛП Нейромидин плюс ЛП Глиатилин. Длительность лечения составила 2 мес. Всем пациентам проводили комплексное клиническое, нейрофизиологическое и лабораторное обследование до начала терапии, через 1 мес и 2 мес от начала терапии: исследование активности холинэстеразы в крови, тестирование по краткой шкале оценки психического статуса (MMSE) и шкале Гамильтона, проведение транскраниальной магнитной стимуляции с определением времени центрального моторного проведения и исследование соматосенсорных вызванных потенциалов с вычислением времени центрального афферентного проведения. Результаты. До начала лечения выявлена значимая положительная сильная корреляционная связь между возрастом пациентов и уровнем активности холинэстеразы в сыворотке крови (Rs=0,77; р=0,0001). На фоне проводимого лечения по всем исследуемым параметрам были получено значимое (р0,05) улучшение всех исследуемых параметров (кроме шкалы MMSE, которая показала лишь тенденцию к улучшению) в 1-й и 3-й подгруппе каждой из групп по сравнению с параметрами, полученными во 2-х подгруппах соответствующих групп. Кроме того, через 2 мес от начала лечения отмечено значимое снижение активности холинэстеразы в сыворотки крови в 1-й и 2-й подгруппе больных. Заключение. Исследование девиаций 'холинергического профиля' (уровень активности холинэстеразы в крови) у пациентов с церебральной патологией и стратегия использования холинергических препаратов, ингибиторов ацетилхолинэстеразы, а также их сочетания для коррекции психоневрологических расстройств являются одним из важных направлений в оптимизации комбинированной терапии больных данного профиля.

To perform a comparative analysis of the efficacy of the original drug meloxicam (movalis) and its generic (amelotex) in the treatment of patients with lower back pain.The analysis of treatment results of 112 (61 men and 51 women) employees of JSC «Admiralteyskie Verfi», aged 18 to 60 years, was carried out. All these patients were treated in the period from 2015 to 2017 at the Medical Center of JSC «Admiralteyskie Verfi» due to dorsalgia of lumbosacral localization (ICD-10, item M54). The average age of the patients was 42,6±10,4 (from 22 to 59 years). Age range of patients was 20-35 years (Compared to amelotex, movalis was more effective for the duration of pain intensity reduction (5±1,4 days (min 3, max 9) in the movalis group and 7,37±1,68 days (min 3, max 10) in the amelotex group) as well as for the total duration of temporary disability (labor losses 6,43±1,4 days (min 4, max 10) and 8,61±1,59 days (min 5, max 12), respectively). In addition, patients receiving movalis showed a more significant improvement in the Clinical Global Impression (CGI) score in all age groups compared with patients in the amelotex group.The lack of therapeutic equivalence between movalis and amelotex determines the relevance of the drug choice for complex therapy of these patients, which will improve the prognosis of the disease and the quality of life of the patient.Сравнительный анализ эффективности оригинального препарата мелоксикама (Мовалис) и дженерика (Амелотекс) при лечении пациентов с болью в нижней части спины.Проведен сравнительный анализ результатов лечения 112 сотрудников АО «Адмиралтейские верфи» в возрасте от 18 до 60 лет (61 мужчина и 51 женщина), находившихся на лечении в Медицинском центре АО «Адмиралтейские верфи» в период с 2015 по 2017 г. с диагнозом дорсалгии пояснично-крестцовой локализации (М54 по МКБ-10). Возраст пациентов составлял 20—35 лет у 34 человек, 36—50 лет у 49 человек, старше 50 лет у 29 человек; средний возраст пациентов 42,6±10,4 года (от 22 до 59 лет).Установлено, что применение Мовалиса оказалось более эффективным по сравнению с применением Амелотекса по таким показателям, как сроки уменьшения интенсивности болевого синдрома — среднее значение в группе больных, принимавших Мовалис (1-я группа), составило 5±1,4 дня (min 3, max 9), в группе принимавших Амелотекс (2-я группа) — 7,37±1,68 дня (min 3, max 10), а также по общей продолжительности временной утраты трудоспособности — среднее значение трудопотерь в 1-й группе составило 6,43±1,4 дня (min 4, max 10), во 2-й группе — 8,61±1,59 дня (min 5, max 12). Кроме того, было выявлено, что у пациентов, получавших Мовалис, во всех возрастных группах наблюдалось более существенное улучшение состояния по шкале общего клинического впечатления по сравнению с больными 2-й группы.Выявленное в нашем исследовании отсутствие терапевтической эквивалентности Мовалиса и Амелотекса определяет актуальность выбора препаратов для комплексной терапии позволит улучшить прогноз заболевания и качество жизни больного.

In the present work, the adhesive strength of the surface alloy with different transition layer thickness was measured. A Ni-Cu surface alloy is formed using successive operations of Ni film deposition followed by mixing in a melted phase with the Cu substrate by a low-energy, high-current electron beam (LEHCEB). A different thickness of the transition layer was obtained by varying the thickness of Ni film deposited during the formation of the surface alloy. The study includes characterization of formed Ni-Cu surface alloys by scanning electron microscopy, in-depth elements distribution and scratch test. The results obtained showed correlation with thickness of the transition layer and adhesive strength of the surface alloy.

In the present work, the calculations of heat regimes for a Ni-Al surface alloy formed on a carbon steel substrate using a low-energy high-current electron beam (LEHCEB) were carried out for two types of multilayered systems with different numbers and thicknesses of the layers. The multilayered system of type 1 was three layered system Ni (0.5 µm)-Al (1.52 µm)-Ni (0.5 µm). The multilayered system of type 2 consists of 10 layers of Ni (0.1 µm each) alternating with 9 layers of Al (0.167 µm each). The total thickness of coating deposited in both cases was 2.5 µm. The melting thresholds for Ni, Al and carbon steel during LEHCEB irradiation were determined by the calculation. The phase diagrams obtained in calculation showed that process of melting occurs similarly for both types of multilayered systems. The calculation demonstrated that the melt thickness on the surface after irradiation by LEHCEB with optimal parameters is about 3 µm, and the average lifetime of the melt is ~ 1 µs (Ni-layers), and ~ 10 µs (Al-layers).

Ni-Al surface alloy electron beam synthesis results are presented. Surface alloy was formed on a carbon steel substrate by multilayer Ni-Al system deposition and subsequent one pulse low-energy high-current electron beam (LEHCEB) treatment in single vacuum cycle. It is shown that surface alloy containing mainly intermetallic phase NiAl is formed as a result of one pulse LEHCEB treatment. It is established that NiAl surface alloy microhardness and wear resistance are higher in comparison to steel substrate parameters.

This paper presents a research data on investigation of physical-mechanical properties of the surface of NiTi shape memory alloy after low-energy high-current pulsed electron beam (LEHCPEB) treatment in surface melting mode. Investigation of physical-mechanical and functional properties (Young’s modulus E IT , dynamic hardness H IT , plasticity characteristic δH, and parameter of shape recovery ratio η) was held by method of instrumented nanoindentation test. Our data suggest that after LEHCPEB treatment physical-mechanical properties of the surface layers of ~500 nm thickness change in depth from the surface without critical influence to the pseudoelastic properties of NiTi alloy.

The results of an experimental and theoretical study of shock-wave processes and spall fracture in an ultrafine-grained and coarse-grained (α + β) Ti–Al–V–Mo alloy under the action of a nanosecond relativistic high-current electron beam are reported. Mathematical modeling is performed to show that when an electron beam with a power density of 1.65 × 1010 W/cm2 impacts this alloy, a shock wave with a compression amplitude of 13 GPa appears and its reflection gives rise to a tensile wave. Its amplitude increases with decreasing target thickness. The calculated increase in the thickness of the spalled layer at the rear surface of the target corresponds to the experimental data. It is established experimentally that plastic deformation precedes the spall fracture sequentially at three structural-scale levels. At the beginning pores are formed and merge, then microcracks are formed at different angles to the back surface of the target between the pores, and then a macrocrack is formed. As a result, the macrocrack surface is not smooth but exhibits pits of ductile fracture.

This paper presents research results on the physiochemical and topographic surface properties of a NiTi alloy and their changes after different surface treatments: mechanical polishing, electron beam cleaning, and TiTa-based surface alloying. The possibility of using electron beam treatment for surface preparation with no additional methods is shown. Experiments demonstrate that the TiTa-based alloy surface formed by multiple magnetron deposition of TiTa film and subsequent pulsed electron beam melting of the film/substrate system is chemically and morphologically homogeneous.