BACKGROUND: Periimplantitis causes implant loss, which reduces the quality of dental treatment. The effect of periimplantitis treatment on the immune response, particularly the chemiluminescent activity of neutrophilic granulocytes, is unclear. The paper addresses this issue, as well as improvements in periimplantitis treatment approaches. AIM: To assess the biocompatibility of implants removed from the inflammation site and treated with Air Flow and laser. MATERIALS AND METHODS: Three types of implant surface were assessed: anodized titanium dioxide (TiO2); sand-blasted, large grit, acid-etched (SLA); and resorbable blast media (RBM). Implants were removed in patients with confirmed periimplantitis, followed by an air-powder abrasive surface treatment with Air Flow and chlorhexidine, using a YSGG laser with a wave length of 2,780 nm. New (out of the box) implants were used as a control. Biocompatibility was assessed by the synthesis of primary and secondary reactive oxygen species (ROS) by neutrophils; the intensity and kinetics of synthesis were examined using chemiluminescence analysis. RESULTS: Lucigenin- and luminol-dependent chemiluminescence of neutrophils was assessed following in vitro incubation with SLA, RMB, and TiO2 implants removed in patients with confirmed periimplantitis and treated with Air Flow and chlorhexidine. The study found a decrease in the time to maximum and an increase in the maximum intensity and area under the curve of spontaneous and zymosan-induced chemiluminescence of neutrophils, regardless of the studied implant type. Changes in the zymosan-induced chemiluminescence of neutrophils following incubation with implants were greater than changes in spontaneous chemiluminescence, resulting in a higher activation index. No significant changes in neutrophil chemiluminescence were observed after in vitro incubation with laser-treated SLA, RMB, and TiO2 implants. CONCLUSION: SLA, RMB, and TiO2 implants removed in periimplantitis patients and treated with Air Flow and chlorhexidine have low biocompatibility. However, Air Flow-treated RBM implants show relatively superior biocompatibility than SLA and TiO2 implants, which is attributed to the decreased synthesis of primary and secondary ROS by neutrophils during in vitro incubation. The degree of ROS synthesis by neutrophils during incubation with laser-treated implants corresponds to that of the control, indicating increased biocompatibility of laser-treated implants. Laser-treated TiO2 implants had the lowest neutrophil activation during incubation, determining their maximum biocompatibility among the studied implants.

The course of infectious diseases caused by viruses, and their common outcome is determined by the activity of the inflammatory reaction which occurs both at the local and systemic levels. However, the features of neutrophil functions during inflammatory reaction are virtually unknown in the patients with infectious mononucleosis (IM), caused by Epstein–Barr virus (EBV). Hence, the aim of our study was to evaluate some characteristics of phenotypic spectrum of blood neutrophils in children with IM. Patients and methods. We examined 84 children aged 3 to 11 years with EBV infection with moderate or severe clinical course of the disease. All patients exhibited a positive test for EBV DNA in blood lymphocytes and appropriate serological markers of acute EBV infection. The control group consisted of 40 conditionally healthy children at the similar age range. The study of neutrophil phenotype was carried out by flow cytometry using direct immunofluorescence of whole peripheral blood samples. A study of the neutrophil phenotype with a combination of two functional antigens (CD64 and CD32) has revealed that in children with IM, regardless of age, the main fraction of blood neutrophils are double-negative cells, whereas in healthy children it consists of CD64-CD32+ neutrophils. The main fraction of neutrophils in the paired combination of CD64 and CD11b antigens in sick children aged 3-6 and 7-11 years was similar to the healthy controls (CD64-CD11b+), but with a change in the content of minor cell fractions. The number of CD64-CD15+ neutrophils (main fraction of cells in healthy children) proved to be significantly reduced in the IM patients of both age groups. However, we have revealed a marked increase in the level of double-negative cells for the CD64 and CD15 antigens. At the same time, the content of double-negative neutrophils for these markers was also increased in IM children of both age groups. The cells with CD11b-CD15+ and CD11b+CD15+ phenotypes comprised the main fractions in IM, as studied by a paired combination of CD11b and CD15 antigens; in healthy children – only CD11b+CD15+ neutrophils are detected. The phenotypic changes of neutrophils during IM suggest a decreased migratory ability of cells with high activity of proinflammatory functions. The established ontogenetic features of the neutrophil phenotype are significantly changed in the children with IM, probably, due to specific immunopathogenesis of the viral infection. The detected changes in phenotypic composition of neutrophils associated with IM may be caused both by the features of protective reaction of innate immune cells and pathogenic effects of the virus itself upon blood neutrophils.

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Background: NK cells phenotype and functional state in different genotypes of chronic viral hepatitis C (CVHC), depending on liver fibrosis severity, have not been sufficiently studied, which limits the possibilities for the development of pathology therapy. Methods: The CVHC diagnosis was based on the EASL recommendations (2018). Clinical examination with liver elastometry was performed in 297 patients with genotype 1 and in 231 patients with genotype 3 CVHC. The blood NK cells phenotype was determined by flow cytometry in 74 individuals with genotype 1 and in 69 individuals with genotype 3 CVHC. Results: The frequency of METAVIR liver fibrosis stages F3–F4 was 32.5% in individuals with genotype 3, and 20.5% in individuals with genotype 1 CVHC (p = 0.003). In patients with both genotype 1 and genotype 3 CVHC, a decrease in the total number of blood NK cells, CD56brightCD16+ NK cells and an increase in the proportion of CD56dimCD16+ NK cells, CD94+ and CD38 + CD73+ NK cells were registered in patients with fibrosis stage F3–F4 by METAVIR in comparison with persons with METAVIR fibrosis stage F0–F1. Conclusions: In patients with both genotype 1 and genotype 3 CVHC, an imbalance in the ratio between cytokine-producing and cytotoxic NK cells and an increase in the content of NK cells that express inhibitory molecules were determined in patients with severe liver fibrosis.

Post-COVID syndrome develops in 10-20% of people who have recovered from COVID-19 and it is characterized by impaired function of the nervous, cardiovascular, and immune systems. Previously, it was found that patients who recovered from infection with the SARS-CoV-2 virus had a decrease in the number and functional activity of NK cells. The aim of the study was to assess the effectiveness of recombinant human IL-2 (rhIL-2) administered to correct NK cell phenotype and functional activity in patients with post-COVID syndrome. Patients were examined after 3 months for acute COVID-19 of varying severity. The phenotype of the peripheral blood NK cells was studied by flow cytometry. It was found that disturbances in the cell subset composition in patients with post-COVID syndrome were characterized by low levels of mature (p = 0.001) and cytotoxic NK cells (p = 0.013), with increased release of immature NK cells (p = 0.023). Functional deficiency of NK cells in post-COVID syndrome was characterized by lowered cytotoxic activity due to the decreased count of CD57+ (p = 0.001) and CD8+ (p < 0.001) NK cells. In the treatment of patients with post-COVID syndrome with recombinant IL-2, peripheral blood NK cell count and functional potential were restored. In general, the effectiveness of using rhIL-2 in treatment of post-COVID syndrome has been proven in patients with low levels of NK cells.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Aim: Studying of the features of phagocytic activity and the state of the respiratory burst of neutrophils under the influence of polyprenols in vitro. Materials and methods. The study involved 30 relatively healthy donors aged 23-59 years from whose peripheral blood neutrophilic granulocytes were isolated to determine phagocytic and chemiluminescent activity. The isolated cells were incubated for 30 minutes with polyprenols in vitro. The level of phagocytosis of immature and mature neutrophils was determined by flow cytometry using FITC-labeled staphylococcal protein A. The state of the respiratory burst was assessed using chemiluminescent analysis. Results. It was found that the levels of phagocytic index (PI) and number (PN) of mature neutrophils were reduced after incubation with polyprenols relative to initial and control values. The values of PI and PN of immature neutrophils under the influence of polyprenols and during control incubation were decreased relative to the initial values. The intensity maximum and area under the curve of spontaneous and zymosan-induced lucigenin- and luminol-dependent chemiluminescence of the neutrophils were reduced after incubation with polyprenols. Conclusion. The effect of polyprenols on neutrophilic granulocytes in vitro leads to a decrease in activity in respiratory burst cells, which is realized in blocking by polyprenols the interaction of primary and secondary ROS with chemiluminescent indicators by the mechanism of primary antioxidants. The binding of ROS by polyprenols also manifests itself in a decrease in the phagocytic activity of mature neutrophils while maintaining the phagocytic activity of immature cells at the level of control incubation. In general, polyprenols exhibit anti-inflammatory activity when exposed in vitro to neutrophilic granulocytes.

Objective : to study of the features of the spread of anxiety syndrome in patients with chronic non-communicable diseases (CNCD) in outpatient practice. Materials and methods : the study included persons of both sexes over 18 years of age who visited outpatient facilities in a large industrial center of Eastern Siberia in the summer of 2022. Diagnosis of chronic NCDs was established according to modern clinical guidelines. The examined were divided into two groups. The first group included persons without NCDs, the second group included patients with concomitant NCDs. The psycho-emotional state was assessed using the Spielberger-Khanin test with separate determination of the levels of personal and situational anxiety. Statistical data analysis was carried out using the Statistica 12.0 software package (StatSoft Inc., USA). Results : the level of situational anxiety in patients with chronic NCDs was statistically significantly higher compared to individuals without concomitant somatic pathology. In patients with chronic NCD, compared with individuals without them, a significant increase in the median scores for the level of low and moderately expressed personal anxiety and for the level of moderate and high situational anxiety was revealed. In the group of patients with CND, a high level of personal and situational anxiety was significantly more often observed in comparison with persons without CND. Conclusion : the prevalence of anxiety syndrome, especially situational anxiety in patients with chronic NCD in the outpatient network is quite high and reaches 93%, which requires a solution to the issue of practical psychiatric care for these patients.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

The main role in the control of tuberculosis infection is played by macrophages and Th1 and CD8+ T cells. The study aimed to identify the most diagnostically significant CD8+ T cell subsets in tuberculosis patients. Methods: Peripheral blood samples from patients with clinical, radiological, and bacteriologically confirmed pulmonary tuberculosis (TB, n = 32) and healthy subjects (HC, n = 31) were collected and analyzed using 10-color flow cytometry. Results: The frequency of the EM4 CD3+CD8+ cells was reduced in the peripheral blood of patients with pulmonary tuberculosis, while the relative and absolute number of EM1 CD3+CD8+ cells increased compared to the control group. CD57 expression was reduced in patients with pulmonary tuberculosis on EM1, EM2, and pE1 CD3+CD8+ cells, whereas the EM3 cells had a high level of CD57 expression. The relative and absolute number of Tc2 (CCR6–CXCR3–) cells in peripheral blood in patients with pulmonary tuberculosis was increased, while the frequency of Tc1 (CCR6–CXCR3+) was decreased, compared to healthy donors. Conclusions: Patients with pulmonary tuberculosis have an abnormal CD3+CD8+ cell profile and demonstrate their impaired maturation and functional activity.

The work is devoted to the study of changes in the structural and physical properties of the precipitation-hardened CuCrZr alloy under the influence of low-temperature (77 K) quasihydroextrusion with various degrees of deformation at liquid nitrogen temperature with subsequent aging. Prior to quasihydroextrusion, commercial alloy samples were annealed and quenched from the premelting temperature to obtain a supersaturated solid solution of alloying elements in the copper matrix. After quasihydroextrusion, the microstructure, lattice constant, pole densities, tensile strength and yield strength, microhardness (in different cross-sections of the extrudate), and electrical conductivity of the CuCrZr alloy were studied depending on the degree of deformation by quasihydroextrusion. It is shown that the deformation degree determines the kinetics of decomposition of the supersaturated solid solution and its structure. As a result of extrusion, an anisotropic structure of the matrix and precipitates is formed, which also determines the anisotropy of material properties. Subsequent aging leads to a significant decrease in the anisotropy of properties. With an increase in the deformation degree during extrusion (before aging), a significant monotonous increase in physical and mechanical properties occurs. However, in the range of deformation degrees of 40–50%, an anomalous “jump” of all measured properties and structural parameters is observed. The study proposes a physical mechanism that explains the experimental results. The mechanism is based on the occurrence of two kinetically differently directed processes: dynamic aging and its inhibition due to an increase in the defectiveness of the material. The latter process manifests itself essentially at low temperatures. In general, low-temperature quasihydroextrusion makes it possible to obtain a complex of sufficiently high mechanical and electrical characteristics of the CuCrZr alloy at relatively low degrees of deformation for one extrusion cycle, which is facilitated by low deformation temperature.

Введение. В сравнении с медикаментозным лечением при имплантации кардиовертеров-дефибрилляторов (ИКД) аритмогенная смертность сокращается на 50%, а общая смертность – на 28%. При этом частота рецидивирующих аритмий и частота ИКД-терапии изучены мало. Цель. Разработка метода прогнозирования желудочковых аритмий у пациентов с ИКД по данным ЭКГ-маркеров электрической нестабильности миокарда. Материалы и методы. Обследовано 76 пациентов с ИКД, из них 71 мужчина (93,4%). Средний возраст – 61,9±12,6 года. Контрольная группа – 151 пациент с ИБС или кардиомиопатией без клинически значимых желудочковых аритмий, средний возраст – 52,4±18,3 года. Контролировали ЭКГ-12, ЭхоКГ, ХМ-ЭКГ и ЭКГ высокого разрешения. Оценивали комплекс следующих ЭКГ-маркеров электрической нестабильности миокарда: фрагментированный комплекс QRS, угол QRS-T >105°, интервал QTкорр. >450 мс, дисперсия QRS >40 мс, альтернация Т-волны >45 мкВ, дисперсия QT >70 мс, дисперсия JT >70 мс, дисперсия Tpeak-Tend >103 мс, турбулентность >0% и замедление сердечного ритма <4,5 мс. Результаты. У 26,1% пациентов с ИКД зарегистрированы пароксизмы желудочковой тахикардии, у 35,0% – превышение QTкорр. >450 мс, у 4,3% – пароксизмы фибрилляции предсердий, увеличение конечно-диастолического диаметра ЛЖ до 62,3±8,4 мм и снижение индекса локальной сократимости до 1,8±0,6 единицы. Уровень электрической нестабильности миокарда у пациентов с ИКД оказался значимо выше, чем у пациентов контрольной группы. Это зафиксировано по таким ЭКГ-маркерам, как фрагментация комплекса QRS, угол QRS-T, дисперсия QRS, дисперсия QT, альтернация T-волны и дисперсия Tp-Te (p<0,022). Разработана модель прогноза желудочковых аритмий у пациентов с ИКД, которая обладает чувствительностью 83%, специфичностью 81% и долей корректного прогноза 80,5%. Обсуждение. У пациентов после имплантации ИКД сохраняется высокая вероятность желудочковых аритмий. У 55,3% пациентов были зафиксированы эпизоды антиаритмической и/или шоковой терапии. В подгруппе с аппаратной терапией ИКД значимо чаще фиксировали электрический шторм (21,8%), сахарный диабет 2-го типа (23,6%) и увеличение конечно-диастолического диаметра левого желудочка (p<0,01). Заключение. Использование ЭКГ-маркеров электрической нестабильности миокарда повышает точность прогноза желудочковых аритмий у пациентов с ИКД. Introduction. Compared to pharmacological treatment during the implantation of cardioverter-defibrillators (ICD), arrhythmic mortality decreases by 50% and overall mortality by 28%. However, the frequency of recurrent arrhythmias and ICD therapy is poorly studied. Purpose. To elaborate a method for predicting ventricular arrhythmias in patients with ICD according to ECG markers of myocardial electrical instability. Materials and methods. A total of 76 patients with ICD were examined, 71 of whom were males (93.4%). Mean age was 61.9±12.6 years. The control group consisted of 151 patients with coronary artery disease or cardiomyopathy without clinically significant ventricular arrhythmias, mean age being 52.4±18.3 years. Electrocardiography (ECG-12), echocardiography, Holter monitoring-ECG, and high-resolution ECG were monitored. A complex of ECG markers of myocardial electrical instability was evaluated, including fragmented QRS complex, QRS-T angle >105°, QTc interval >450 ms, QRS dispersion >40 ms, T wave alternation >45 μV, QT dispersion >70 ms, JT dispersion >70 ms, Tpeak-Tend dispersion >103 ms, turbulence >0%, and heart rate deceleration <4.5 ms. Results. Ventricular tachycardia paroxysms were registered in 26.1% of patients with ICD, QTc interval >450 ms in 35.0%, and atrial fibrillation paroxysms in 4.3%. Left ventricular end-diastolic diameter increased to 62.3±8.4 mm, and local contractility index decreased to 1.8±0.6 units. The level of myocardial electrical instability in patients with ICD was significantly higher than in the control group, as indicated by ECG markers such as QRS complex fragmentation, QRS-T angle, QRS dispersion, QT dispersion, T wave alternation, and Tp-Te dispersion (p<0.022). A model for predicting ventricular arrhythmias in patients with ICD was developed having a sensitivity of 83%, specificity of 81%, and an accuracy rate of 80.5%. Discussion. The probability of ventricular arrhythmias remains high in patients with ICDs. 55.3% of patients experienced episodes of antiarrhythmic and/or shock therapy. In the subgroup with apparatus therapy, electrical storm (21.8%), type 2 diabetes mellitus (23.6%) and increased left ventricular end-diastolic diameter were significantly more frequent (p<0.01). Conclusion. The use of ECG markers of myocardial electrical instability improves the accuracy of predicting ventricular arrhythmias in patients with ICD.

The pandemic of the new coronavirus infection COVID-19, caused by the SARS-CoV-2 virus, continues to be a serious problem for the entire global community. Currently, most patients experience mild COVID-19, with only about 20% of those infected requiring hospitalization. The severe course of COVID-19 is most often associated with damage to the patient’s bronchopulmonary system by the virus and serious abnormalities, including damage to the air-hematological barrier, systemic inflammation, dysfunction of the immune system and the addition of secondary infections. Severe disease and poor outcome in hospitalized patients with COVID-19 may be associated with lymphopenia in combination with neutrophilia. Restoring the number of lymphocytes is important to improve the prognosis of the patient’s outcome. Patients with COVID-19 experience an immune imbalance where systemic inflammation and dysfunction of circulating T and B cells lead to more severe disease. TREC/KREC analysis can characterize the function of the central organs of the immune system and its relationship with clinical and laboratory data. Decreased TREC/KREC levels were observed in patients with unfavorable disease outcomes compared to patients with favorable disease outcomes. Additionally, a higher neutrophil to lymphocyte ratio was found. Levels of TREC and KREC in the blood negatively correlate with the neutrophil-lymphocyte ratio. Thus, the TREC/KREC assay is a potential prognostic marker for assessing the severity and outcome of COVID-19.

Background: T and B cell-mediated immunity can be assessed using T cell receptor excision circle (TREC) and Kappa-deleting recombination excision circle (KREC) analysis, respectively, and successful implementation of this method requires evaluation of the correlation between the TREC frequencies and T cell subsets as well as KREC levels and B lymphocyte subsets. The aim of the present study was to evaluate the correlation between the TREC/KREC concentrations and T/B lymphocyte subsets at different stages of COVID-19. Methods: We examined 33 patients in the acute stage of COVID-19 (including 8 patients with poor outcomes) and 33 COVID-19 survivors. TREC/KREC concentrations were measured using quantitative real-time PCR. T/B lymphocyte subsets were determined using flow cytometry. Results: Blood TREC and KREC levels were found to be significantly lower in the acute stage of COVID-19 compared to control values. Moreover, a zero blood TREC level was a predictor of a poor disease outcome. Reductions in CD3+CD4+CD45RO−CD62L− and CD3+CD8+CD45RO−CD62L− T cell counts (as well as in the main fractions of B1 and B2 B cells) indicated a favorable outcome in COVID-19 patients in the acute stage of the disease. Decreased CD3+CD4+CD45RO−CD62L+ and CD3+CD8+CD45RO−CD62L+ T cell frequencies and increased CD3+CD8+CD45RO−CD62L− cell counts were found to indicate a poor outcome in patients with acute COVID-19. These patients were also found to have increased B1 cell counts while demonstrating no changes in B2 cell counts. The levels of effector T cell subsets an naïve B cells were normal in COVID-19 survivors. The most pronounced correlations between TREC/KREC levels and T/B cell subsets counts were observed in COVID-19 survivors: there were positive correlations with naïve T and B lymphocytes and negative correlations with central and effector memory T cell subsets. Conclusions: The assessment of correlations between TREC and T cell subsets as well as KREC levels and B cell subset counts in patients with acute COVID-19 and COVID-19 survivors has shown that blood concentrations of TREC and KREC are sensitive indicators of the stage of antigen-independent differentiation of adaptive immunity cells. The results of the TREC and KREC analysis correlated with the stages of COVID-19 and differed depending on the outcome of COVID-19.

BACKGROUND: Tumor microenvironment modulates (including with the help of metabolites) the functional activity of the neutrophils that contribute to the reprogramming of the antitumor activity into a protumor one. AIMS: To study the phagocytic and chemiluminescent activity of neutrophils in patients with bladder cancer (BC) under the influence of metabolites of the tumor microenvironment in vitro. MATERIALS AND METHODS: We examined 37 patients with superficial BC (T1,а,isN0M0) and considered 32 healthy individuals as a control group. Neutrophils isolated from their blood were incubated in vitro with lactate, ADP, and glutamate. Phagocytic activity was examined using flow cytometry, and the intensity of the respiratory burst of neutrophils was evaluated via chemiluminescent analysis. RESULTS: In patients with BC, the phagocytic index (PhI) values are reduced compared to the control sample (without in vitro metabolite exposure) and when exposed to glutamate, while the effect of lactate on cells causes an increase in the phagocytic number and PhI. Moreover, under the influence of lactate in vitro, the activity of spontaneous and zymosan-induced chemiluminescence of neutrophils decreases. ADP causes a decrease in spontaneous chemiluminescence only. Finally, under the influence of glutamate, the indicators of spontaneous and induced chemiluminescence decrease. CONCLUSIONS: Under the influence of lactate and ADP (products of tumor cells), the phagocytic activity of a population of immature neutrophils is stimulated, which leads to myeloid suppressor cells that inhibit antitumor immunity. Thus, metabolites of the tumor microenvironment modulate the activity of the respiratory burst of neutrophils in patients with BC.

Objective. To analyze the phenotype of B-lymphocytes in patients with chronic infection with hepatitis C virus (HCV) before and after treatment with direct-acting antivirals (DAAs) depending on the virus genotype. Patients and methods. This open-label clinical and immunological study included 111 HCV patients with a mean age of 43.4 ± 8.6 years who received DAAs: Sofosbuvir (400 mg) and Velpatasvir (100 mg) once a day for 12 weeks. We assessed the phenotypic diversity of B-lymphocytes in peripheral blood of HCV patients during therapy and after its completion depending on the virus genotype. Results. Prior to DAA initiation, HCV patients demonstrated elevated count of CD19+CD5+CD27+ B cells and CD23+ B cells along with a decreased count of CD19+CD5–CD27+ B cells compared to controls. After therapy with DAAs, HCV patients continued to have increased proportion of CD19+CD5+CD27+ cells and reduced proportion of CD19+CD5–CD27+ cells. Conclusion. The pretreatment phenotypic diversity of peripheral B cells in HCV patents did not depend on the HCV genotype and was characterized by increased levels of B1 memory cells and activated B cells of the main subpopulations, along with a decreased level of B2 memory cells. The changes in the count of different B-cell subpopulations after DAA therapy depend on HCV genotype and might be associated with the rate of virus elimination. Key words: B-lymphocytes, immune system, direct-acting antivirals, chronic hepatitis C

The paper is devoted to the investigation of the structure and properties of coatings obtained by micro-arc oxidation (MAO). For the first time, the possibility of using sub-terahertz ellipsometry with an operating frequency f = 0.14 THz for non-destructive non-contact determination of the integral values of the thickness, structure, and composition of such coatings is studied. The frequency was chosen since the corresponding wavelength (lambda = 2.14mm) significantly exceeds the characteristic size of the roughness of the coatings, which makes it possible to use the geometrical optics approximation in the analysis of experimental results. When constructing models of the structure of coatings and determining their parameters, additional independent methods were used, such as optical microscopy, XRD, SEM, terahertz reflectometry, and the theoretical modeling of the electric field distribution during the microplasma oxidation process. The A1 alloy 1100 was used as the material for research. It is shown that ellipsometry is very sensitive to processes on the surface during MAO even at the earliest stages of oxide layer formation. Based on the data of the ellipsometry experiment, several planar models of the surface structure were constructed, and their parameters were determined at different stages of oxidation. The constructed models and their parameters (thickness, phase composition, and optical constants) are in good agreement with the results of independent measurements and do not contradict the physical concepts of the processes occurring during MAO. For the first time, it was proposed to use piecewise models for interpreting ellipsometric measurements of film structures non-uniform over the surface. The proposed model adequately describes the structure of MAO coatings at all stages of the technological process. It makes it possible to use ellipsometry for non-destructive non-contact express control of the state of these coatings during production without resorting to additional more complex analytical methods (XRD, SEM, etc). When analyzing ellipsometric data, estimates for the optical constants of mullite (Al5SiO10_x) in the terahertz range were obtained for the first time. It is also shown that the main results of the work can be used in the analysis of MAO coatings on other metals.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)