Surface structure of commercially pure VT1-0 titanium irradiated by an intense pulsed electron beam

It is shown that pulsed electron beam irradiation of commercially pure titanium at a beam energy density of 10 J/cm{2}, pulse duration of 150 [mu]s, number of pulses of N=5 pulses, and pulse repetition frequency of 0.3 Hz with attendant polymorphic [alpha]->[beta]->[ alpha] transformations allows a more than five-fold decrease in the grain and subgrain sizes of the material structure

Modification of the surface layer of the system coating (TiCuN)/substrate (A7) by an intensive electron beam

In order to study the conditions of modification of the surface layer of the system coating (TiCuN)/substrate (A7) an analysis of processes occurring in the surface layer of the system wear-resistant coating/substrate irradiated by an intensive pulsed electron beam at a submillisecond exposure time has been carried out on the example of aluminum and titanium nitride. Irradiation has been carried out under conditions ensuring melting and crystallization of the surface layer of the material by a nonequilibrium phase diagram. It has been experimentally established that irradiation of the system coating (TiCuN)/substrate (A7) by an intensive electron beam is accompanied by changes in the phase composition of the material. It is evident that nanostructuring of the aluminum layer adjacent to the coating, and formation in it of nitride phase particles will contribute to hardening of the surface layer of the material, creating a transition sublayer between a solid coating and a relatively soft volume. The carried out analysis shows that binary nitrides based on TiN1-x are most likely to form under nonequilibrium conditions, since the homogeneity range of this compound is rather large. On the other hand, formation of the ternary compound Ti3CuN, which can be formed after an arc plasma-assisted deposition of titanium nitride of the composition TiCuN and by the subsequent intensive pulsed electron beam exposure, cannot be excluded

FG Sge: new multicolor photometry and short-term dust shell clearing in 2019

We present the results of a new stage of the long-term photometric study of FG Sge which is a quickly evolving central star of the planetary nebula Hen 1-5. Our new observations carried out on the SAI MSU telescopes in the optical ($BVR_CI_C$) and infrared (IR) ($JHKLM$) regions in 2008-2021 and 2013-2021, respectively, allowed us to trace the evolution of the star's brightness in recent years. The most significant observations were performed in 2019 when the star suffered a short clearing of the dust shell and became visible in $BVR_C$. Based on the spectral energy distribution of FG Sge in the 0.4-5 $\mu$m wavelength range we derived the dust shell parameters: the size of dust grains $a=0.01\mu$m, the inner radius temperature $T_{\text{dust}}=900$ K, optical depth $\tau (K)=0.5$ ($\tau (V)=4.5$), the total mass of dust $M_{\text{dust}}=7\cdot10^{-5} M_{\odot}$. After the short-term clearing of the dust shell in 2019, another dust structure was ejected that resulted in the star fading in all the observed bands. Based on the IR brightness and color curves, we estimated the dust depth growth in 2019-2020.Comment: 17 pages, 9 figures, 3 tables. Accepted for publication in Astronomy Letter

Modern Approaches to the Diagnosis of Cognitive Impairment and Alzheimer’s Disease: A Narrative Literature Review

BACKGROUND: The aging of the worlds population leads to an increase in the prevalence of age-related diseases, including cognitive impairment. At the stage of dementia, therapeutic interventions become usually ineffective. Therefore, researchers and clinical practitioners today are looking for methods that allow for early diagnosis of cognitive impairment, including techniques that are based on the use of biological markers. AIM: The aim of this literature review is to delve into scientific papers that are centered on modern laboratory tests for Alzheimers disease, including tests for biological markers at the early stages of cognitive impairment. METHODS: The authors have carried out a descriptive review of scientific papers published from 2015 to 2023. Studies that are included in the PubMed and Web of Science electronic databases were analyzed. A descriptive analysis was used to summarized the gleaned information. RESULTS: Blood and cerebrospinal fluid (CSF) biomarkers, as well as the advantages and disadvantages of their use, are reviewed. The most promising neurotrophic, neuroinflammatory, and genetic markers, including polygenic risk models, are also discussed. CONCLUSION: The use of biomarkers in clinical practice will contribute to the early diagnosis of cognitive impairment associated with Alzheimers disease. Genetic screening tests can improve the detection threshold of preclinical abnormalities in the absence of obvious symptoms of cognitive decline. The active use of biomarkers in clinical practice, in combination with genetic screening for the early diagnosis of cognitive impairment in Alzheimers disease, can improve the timeliness and effectiveness of medical interventions

A flare in the optical spotted in the changing-look Seyfert NGC 3516

We present observations from the short-term intensive optical campaign (from Sep2019 to Jan2020) of the changing-look Seyfert NGC 3516. This active galactic nucleus is known to have strong optical variability and has changed its type in the past. It has been in the low-activity state in the optical since 2013, with some rebrightening from the end of 2015 to the beginning of 2016, after which it remained dormant. We aim to study the photometric and spectral variability of NGC 3516 from the new observations in U- and B-bands and examine the profiles of the optical broad emission lines in order to demonstrate that this object may be entering a new state of activity. NGC 3516 has been monitored intensively for the past 4 months with an automated telescope in U and B filters, enabling accurate photometry of 0.01 precision. Spectral observations were triggered when an increase in brightness was spotted. We support our analysis of past-episodes of violent variability with the UV and X-ray long-term light curves constructed from the archival Swift data. An increase of the photometric magnitude is seen in both U and B filters to a maximum amplitude of 0.25mag and 0.1 mag, respectively. During the flare, we observe stronger forbidden high-ionization iron lines than reported before, as well as the complex broad Ha and Hb lines. This is especially seen in Ha which appears to be double-peaked. It seems that a very broad component of ~10,000 km/s in width in the Balmer lines is appearing. The trends in the optical, UV, and X-ray light curves are similar, with the amplitudes of variability being significantly larger in the case of UV and X-ray bands. The increase of the continuum emission, the variability of the coronal lines, and the very broad component in the Balmer lines may indicate that the AGN of NGC 3516 is finally leaving the low-activity state in which it has been for the last ~3 years.Comment: 7 pages, 6 figures, accepted in A&A (corrected after receiving comments from the language editor

Problematic Internet Usage by Adolescents with Disabilities

Introduction. The intensive development of adaptive information technologies leads to the active inclusion of adolescents with disabilities in Internet communications, expanding the possibilities of their social adaptation. At the same time, the limitation of opportunities for social interaction due to impaired psychophysical development is an additional factor in the uncontrolled involvement of adolescents in Internet communication and the risk of Problematic Internet Usage.The aim of this research is to study the degree and indicators of Internet addiction among adolescents with disabilities in conjunction with indicators of their social adaptability.Methodology and research methods. Theoretical and empirical study is based on the provisions of the psychological theory of activity and personality, culturalhistorical theory of L. S. Vygotsky, the ideas of domestic and foreign psychology about addictive behaviour including about risk and factors of Internet addictive behaviour normally developing adolescents and adolescents with disabilities. The study was carried out using empirical methods (questionnaires, psycho-diagnostic methods, survey methods); methods of quantitative analysis of empirical data, including methods of mathematical statistics: comparison of samples by the Mann-Whitney test; correlation analysis using the linear Pearson correlation coefficient. The calculations were performed using the Excel software package and using the SPSS 16.0 software package (Statistical Package for Social Science).Research results and scientific novelty. The general and specific features of the Internet usage among adolescents with disabilities are identified; personality traits are identified as a prerequisite for the Problematic Internet Usage in this category of adolescents. It has been determined that virtual communication acts for adolescents with disabilities as a kind of adaptation-compensatory resource that allows overcoming communicative difficulties. At the same time, inadequate selfregulation of behaviour makes it difficult for self-control to stay online and thereby increases the risk of the negative impact of interaction on the Internet on their physical and mental state. It is revealed that the personal background of the Problematic Internet Usage has specificity depending on the nature of developmental disorders in adolescents.Practical significance. The results of the research can be used in the work of a psychologist and a teacher for the diagnosis, prevention and correction of Internet addiction by adolescents with disabilities.Введение. Интенсивно развивающиеся адаптивные информационные технологии, с одной стороны, позволяют людям с ограниченными возможностями здоровья (ОВЗ) активно включаться в дистанционные коммуникации, что существенно облегчает процессы их социальной адаптации. С другой стороны, неконтролируемое использование Интернета и нелимитированное общение в сети, особенно в подростковом возрасте, являются дополнительными факторами риска, возрастающего в случае нарушений психофизического развития. Цель представленной в статье работы – изучение проблемы интернет-зависимости старших школьников с ОВЗ в ее взаимосвязи с уровнем их социальной адаптированности. Методология и методики. Теоретико-эмпирическое исследование реализовано с опорой на положения культурно-исторической теории Л. С. Выготского и представления отечественной и зарубежной психологии о проблемном использовании Интернета и об интернет-аддикции у нормально развивающихся подростков и их сверстников с ОВЗ. В ходе изыскания использовались такие эмпирические методы, как анкетирование, психодиагностика и опрос; а также качественный и количественный виды анализа полученных данных, включая методы математической статистики (сравнение показателей выборок по критерию Манна-Уитни); корреляционный анализ с применением линейного коэффициента корреляции Пирсона. Вычисления проводились с помощью пакета программ «Excel» и SPSS 16.0 (Statistical Package for Social Science – Статистический пакет для социальных наук).Результаты и научная новизна. Установлены общие и специфические особенности поведения старших школьников с ОВЗ в сети Интернет. Выявлены качества личности, служащие предпосылками формирования интернет-зависимости у данной категории учащихся. Утверждается, что виртуальная коммуникация для подростков с ОВЗ выступает своего рода адаптационно-компенсаторным ресурсом, помогающим преодолевать коммуникативные сложности. В то же время недостаточная саморегуляция поведения затрудняет самоконтроль в периоды пребывания в сети, что увеличивает риски негативного влияния взаимодействий с Интернетом на физическое и психическое состояние. Индивидуальные предпосылки проблемного использования виртуального пространства обусловлены характером психофизических нарушений у подростка с ОВЗ. Практическая значимость. Материалы и результаты исследования могут быть использованы в работе психологов и педагогов для диагностики, профилактики и коррекции интернет-зависимости старших школьников с ОВЗ

Assessment of the temporomandibular joint condition using two-dimensional ultrasound scanning and doppler ultrasonography methods in patients with chronic inflammatory periodontal diseases

Introduction. Currently, dentists are increasingly detecting changes in the temporomandibular joint in patients with chronic inflammatory periodontal disease.Aim of the study. To carry out a comprehensive dynamic assessment of the temporomandibular joint (TMJ) condition and the registration of regional blood flow using two-dimensional ultrasound scanning to improve the efficiency of diagnostics of inflammatory periodontal diseases.Materials and methods. The study included 2 groups of patients: group 1 (control) consisted of 20 volunteers aged 20–25; Group 2 consisted of 52 people aged 25–45 years with moderate chronic periodontitis. For TMJ ultrasound and Doppler ultrasound, a portable ultrasound scanner LogicScan  128 with an HL-10  linear ultrasound transducer  with an operating frequency of 5     to 12 MHz was used.Results and discussion. During ultrasound examination of the temporomandibular joint and measuring the size of the joint space in patients with moderate chronic periodontitis in a state of relative physiological rest, the following  values were obtained:   in the anterior region – 2.3 ± 0.5 mm; in the upper section – 1.6 ± 0.6 mm; in the posterior section – 1.8 ± 0.3 mm. We also measured the area of the temporomandibular joint disc in various positions. According to ultrasound data, an increase in the size of the joint space from 12.2 to 16.1% and an increase in the area of the articular disc by 17.1 to 36.7% were found in patients with chronic periodontitis. When assessing the trajectory of the articular track, motion delay and joint wedging are determined. In addition, in the color Doppler mapping (CDM) mode, the speed and index indicators of Doppler ultrasonography of the external carotid and temporal arteries were calculated.Conclusions. Modern diagnostic methods of ultrasound and Doppler mapping, assessing the hemodynamics and functional state of the TMJ, allow early diagnosis of changes in order to prevent the development of TMJ disorders in patients with chronic inflammatory periodontal diseases