Conductivity, weak ferromagnetism and charge instability in α−MnS\alpha-MnS single crystal

The temperature dependence of resistivity, magnetization and electron-spin resonance of the $\alpha- MnS$ single crystal were measured in temperature range of $5 K < T < 550 K$. Magnetization hysteresis in applied magnetic field up to 0.7 T at $T=5 K, 77 K, 300 K$, irreversible temperature behavior of magnetization and resistivity were found . The obtained data were explained in terms of degenerate tight binding model using random phase approximation. The contribution of holes in $t_{2g}$ and $e_g$ bands of manganese ions to the conductivity, optical absorbtion spectra and charge instability in $\alpha -MnS$ were studied. Charge susceptibility maxima resulted from the competition of the on-site Coulomb interaction between the holes in different orbitals and small hybridization of sub-bands were calculated at $T=160 K, 250 K, 475 K$.Comment: 6 pages, 12 figure

ПСИХОЛОГИЧЕСКИЕ ХАРАКТЕРИСТИКИ БОЛЬНЫХ ХРОНИЧЕСКОЙ СЕРДЕЧНОЙ НЕДОСТАТОЧНОСТЬЮ В ПЕРИОД ОЖИДАНИЯ ТРАНСПЛАНТАЦИИ СЕРДЦА

Introduction. Numerous studies have established the role of psychological factors in the development, treatment, prognosis of the cardiovascular diseases, as well as in formation of compliance and the quality of patients’ lives. However, few of any psychological studies of patients with chronic heart failure (CHF) waiting for transplantation were carried out, despite the obvious need for reliable psychosocial assessments in the preoperative period and development of psychological support programs. In view of the foregoing, a pilot screening study aimed at assessing the state of the cognitive and affective spheres, personal characteristics of patients with CHFwaiting for the HTas wellanalyzing the relationship between psychological, medical and biological characteristics of patients.Material and methods. 30 patients withCHF took part in the study at theFederal State-Funded Institution «Federal Almazov North-West Medical Research Centre» (Saint-Petersburg). The authors’ structured interviews and psychodiagnostic methods were used in the study: «The index of well-being», (WHO, 1999), «The Brief Neuropsychological Cognitive Examination» (BNCE), «The Zung Self-Rating Depression Scale» (SDS), «The State-Trait Anxiety Inventory» (STAI), «Test the Big Five» (BIG V). Statistical data processing was performed using the Mann–Whitney U criterion and the Spearman correlation (SPSS v. 20.0).Results. Absence of violations of cognitive functions was revealed in 23 % of respondents, mild degree of cognitive deficiency – in 60 %, average degree – in 17 %. The lowest average scores were obtained in the BNCE subtests, reflecting the success of active attention, visual-spatial memory, psychomotorics, abstract thinking.The average group index of depression was 45.9±7.2 (normative level). A detailed analysis showed that absence of signs of depression occurred in 74 % of patients, subdepression – in 23 %, moderately expressed depression – in 3 %. In the entire sample, the average level of situational anxiety prevailed (42.4±6.8) with personal anxiety (39.7±8.1). According to the averaged scales of the BIG V questionnaire, moderately pronounced extroversion features predominated in the patient’s personality structure. The relationship between BNCE indices and duration of chronic HF (r = –0.676, p &lt;0.001) was revealed. A statistically significant reduction in the overall level of cognitive function in patients with concomitant diabetes mellitus was found in comparison with patients without it (U = 61) at p = 0.033; According to the data of SDS depressive symptoms in patients with IHD are more pronounced in comparison with patients with dilated cardiomyopathy U = 47 (p = 0.019).Введение. В многочисленных исследованиях показана роль психологических факторов в развитии, течении, лечении, прогнозе заболеваний сердечно-сосудистой системы, в формировании комплаенса и качества жизни больных. Однако психологические исследования больных хронической сердечной недостаточностью (ХСН) в период ожидания трансплантации органа практически не проводились, несмотря на их очевидную необходимость для совершенствования психосоциальной оценки в предоперационном периоде и разработки программ психологического сопровождения. В связи с этим проведено пилотное скрининговое исследование, имеющее целью оценить состояние когнитивной и аффективной сферы, характеристики личности больных ХСН, находящихся в листе ожидания трансплантации сердца, а также взаимосвязь психологических и медико-биологических характеристик больных.Материал и методы. В СЗФМИЦ им. В. А. Алмазова (Санкт-Петербург) исследованы 30 пациентов с диагнозом ХСН 2б. Использовались авторское структурированное интервью и психодиагностические методы «Индекс общего самочувствия» (ВОЗ, 1999), тестовая батарея «Краткое нейропсихологическое обследование когнитивной сферы» (КНОКС), «Шкала самооценки депрессии» (SDS), «Шкала реактивной и личностной тревожности» (STAI), личностный опросник «Большая пятерка» (BIGV). Статистическая обработка данных произведена с помощью U-критерия Манна–Уитни и корреляции Спирмана («SPSS v. 20.0»).Результаты исследования. Отсутствие нарушений когнитивных функций выявлено у 23 % респондентов, легкая степень когнитивного дефицита – у 60 %, средняя степень – у 17 %. Наиболее низкие средние оценки получены в субтестах КНОКС, отражающих успешность активного внимания, зрительно-пространственной памяти, психомоторики, абстрактного мышления. Средний групповой показатель выраженности депрессии составил 45,9±7,2 (нормативный уровень). Детальный анализ показал отсутствие признаков депрессии у 74 % пациентов, субдепрессию – у 23 %, умеренно выраженную депрессию – у 3 %. Во всей выборке преобладал средний уровень ситуативной тревожности (42,4±6,8) и личностной тревожности (39,7±8,1). Согласно полученным данным, в структуре личности пациентов преобладали умеренно выраженные черты экстраверсии. Выявлена связь между показателями КНОКС и продолжительностью ХСН (r =–0,676, p&lt;0,001). Обнаружено статистически значимое снижение общего показателя состояния когнитивных функций у пациентов с сопутствующим сахарным диабетом по сравнению с пациентами без него (U=61) (р=0,033); показатель депрессии, согласно данным методики SDS, у больных ИБС значимо выше в сравнении с больными с дилатационной кардиомиопатией (U=47) (р=0,019)

РЕНТГЕНО-ГРАФИЧЕСКИЙ АНАЛИЗ КАЧЕСТВА СЕМЯН ОВОЩНЫХ КУЛЬТУР

The possibility of application of radiography in production and study of vegetable seeds and its advantages (rapid test method, multipurpose application etc.) are described in the articleПоказаны возможность применения метода рентгенографии в семеноводстве и семеноведении овощных культур, и его достоинства, заключающиеся в его экспрессности, неразрушаемом характере и многоцелевом применении

Проблема химиорезистентности PRAME-экспрессирующей клетки меланомы и способ ее преодоления c помощью бортезомиба

Background. PRAME gene spontaneous expression is frequently observed in a cancer cell. The protein encoded by this gene increases  the viability of tumour cell. NF-κB signalling pathway takes part in PRAME upregulation. It proposes, that stress conditions may increase the expression level of PRAME in the tumour cell and increase cell’s viability after it. We hypothesized that this phenomenon determines chemoresistance of PRAME-expressing cell, which can be overcome by NF-κB inhibitors, such as bortezomib.Materials and methods. We incubated A875 melanoma cells with cisplatin, bortezomib and dexamethasone, as well as with a mixture  of cisplatin with bortezomib and cisplatin with dexamethasone within 24 hours. To assess the cytotoxicity of these combinations MTT-test was used. For evaluation of PRAME expression level, real-time polymerase chain reaction was used. All data were analyzed with Wilcoxon test for coupled samples.Results. It was found that cisplatin and dexamethasone increased an expression level of PRAME compared to control (p &lt;0.03). The addition of dexamethasone to cisplatin reduced cytotoxic effect of cisplatin. Bortezomib has a cytotoxic effect, but it did not increase the activity  of PRAME gene (p = 0.12). PRAME gene activity in cells incubated with a mixture of cisplatin and bortezomib was observed at a lower level in comparison with cells incubated with cisplatin (p = 0.0277).Conclusion. The results of experiments show that an increase of PRAME expression level reduces the sensitivity of melanoma cells to the cytotoxic effect of cisplatin. PRAME activity increases under stress conditions. Using of bortezomib can inhibit the growth of PRAME expression and makes the tumour cell more vulnerable to cytotoxic agents. On the other hand, dexamethasone may increase a resistance  of PRAME-expressing cell to cytotoxic effects.Введение. В настоящее время показано, что активность раково-тестикулярного гена PRAME, характерная только для опухолевой клетки, может контролироваться сигнальным каскадом NF-κB. Белок PRAME увеличивает жизнеспособность опухолевой клетки. Отсюда следует, что стрессовые условия могут повышать уровень экспрессии PRAME и увеличивать жизнеспособность опухолевой клетки. Мы предположили, что данный феномен определяет химиорезистентность PRAME-экспрессирующей клетки. Эту резистентность можно преодолеть ингибиторами NF-κB-пути, такими как бортезомиб.Материалы и методы: инкубирование в течение суток клеток меланомы линии A875 с цисплатином, бортезомибом и дексаметазоном, смесью цисплатина и бортезомиба, а также со смесью цисплатина и дексаметазона. Для оценки цитотоксичности применяемых препаратов использовали МТТ-тест, уровня экспрессии гена PRAME – полимеразную цепную реакцию в реальном времени. Анализ данных проводили с помощью критерия Вилкоксона для связанных выборок.Результаты. Установлено, что цисплатин и дексаметазон увеличивают уровень экспрессии PRAME по сравнению с клетками меланомы линии A875, не подвергнутыми действию экспериментальных веществ (p &lt;0,03). Добавление дексаметазона к цисплатину снижает цитотоксический эффект последнего. Бортезомиб обладает цитотоксическим действием, но практически не увеличивал активность гена PRAME (p = 0,12). В клетках, инкубированных со смесью цисплатина и бортезомиба, активность гена PRAME находилась на более низком уровне по сравнению с клетками, инкубированными с цисплатином (p = 0,0277).Заключение. Результаты экспериментов показывают, что увеличение уровня экспрессии гена PRAME снижает чувствительность клеток к цитотоксическому действию цисплатина. Активность PRAME увеличивается в условиях стресса. Применение бортезомиба препятствует росту уровня экспрессии PRAME и делает опухолевую клетку более уязвимой к цитотоксическим агентам. С другой стороны, дексаметазон может увеличить резистентность PRAME-экспрессирующей клетки к цитотоксическому воздействию цисплатина

ON THE POSSIBILITY OF USING THE LOCAL APPROXIMATION METHOd TO PREdICT IRREGULAR TIME SERIES OF MINING MACHINE FAILURES

Sustainable development of mining technologies implies the introduc-tion and implementation of the key messages and approaches of Industry 4.0. 'Industry 4.0' is generally applied to characterise new, advanced and potentially breakthrough technologies. digital transformation in the min-ing industry is primarily aimed at increasing productivity. the long-term programme for the development of the mining industry in the russian federation until 2030 sets the objective of a fivefold increase in productiv-ity and key level indicators by at least a factor of 2 to 3. at the same time, industrial and environmental safety standards require mining enterprises to operate machinery and equipment in good working order with the pos-sibility of continuous monitoring of their technical condition. reliability of mining equipment is a significant problem, so research aimed at further study of issues of forecasting breakdowns and failures, are relevant and in demand. the method of local approximation implemented in this work has the distinct advantage of using piecewise linear approximation instead of global-linear approximation, which is a typical autoregressive method. fore-casting remains an important step towards preventing mining equipment failures. Implementation at mining enterprises of an up-to-date efficient sys-tem for forecasting changes in the condition of mining and transportation equipment is a key tool for minimising its downtime, extending the service life of equipment and reducing the cost of equipment maintenance. It is established that failure rate of nodes and units of new generation mining loader-dumping machines is determined not only by mining and geological conditions of operation, but also by a considerable share of repair works that indicates a low level of maintenance and repair works of this type of machines. Implementation of a predictive model based on the method of local approximation of irregular time series of failures of mining transport machines will allow predicting the rational functioning of technological processes of mining of minerals in complex mining conditions. © I.A. grishin, V.S. Velikanov, O.V. Nazarov, N.V. dyorina, 2022Ministry of Education and Science of the Russian Federation, Minobrnaukathis work was financially supported by the Ministry of Science and higher Education of the russian federation (Project No. fZru-2020-0011)

PSYCHOLOGICAL CHARACTERISTICS IN PATIENTS WITH CHRONIC HEART FAILURE WAITING FOR HEART TRANSPLANTATION

Introduction. Numerous studies have established the role of psychological factors in the development, treatment, prognosis of the cardiovascular diseases, as well as in formation of compliance and the quality of patients’ lives. However, few of any psychological studies of patients with chronic heart failure (CHF) waiting for transplantation were carried out, despite the obvious need for reliable psychosocial assessments in the preoperative period and development of psychological support programs. In view of the foregoing, a pilot screening study aimed at assessing the state of the cognitive and affective spheres, personal characteristics of patients with CHFwaiting for the HTas wellanalyzing the relationship between psychological, medical and biological characteristics of patients.Material and methods. 30 patients withCHF took part in the study at theFederal State-Funded Institution «Federal Almazov North-West Medical Research Centre» (Saint-Petersburg). The authors’ structured interviews and psychodiagnostic methods were used in the study: «The index of well-being», (WHO, 1999), «The Brief Neuropsychological Cognitive Examination» (BNCE), «The Zung Self-Rating Depression Scale» (SDS), «The State-Trait Anxiety Inventory» (STAI), «Test the Big Five» (BIG V). Statistical data processing was performed using the Mann–Whitney U criterion and the Spearman correlation (SPSS v. 20.0).Results. Absence of violations of cognitive functions was revealed in 23 % of respondents, mild degree of cognitive deficiency – in 60 %, average degree – in 17 %. The lowest average scores were obtained in the BNCE subtests, reflecting the success of active attention, visual-spatial memory, psychomotorics, abstract thinking.The average group index of depression was 45.9±7.2 (normative level). A detailed analysis showed that absence of signs of depression occurred in 74 % of patients, subdepression – in 23 %, moderately expressed depression – in 3 %. In the entire sample, the average level of situational anxiety prevailed (42.4±6.8) with personal anxiety (39.7±8.1). According to the averaged scales of the BIG V questionnaire, moderately pronounced extroversion features predominated in the patient’s personality structure. The relationship between BNCE indices and duration of chronic HF (r = –0.676, p &lt;0.001) was revealed. A statistically significant reduction in the overall level of cognitive function in patients with concomitant diabetes mellitus was found in comparison with patients without it (U = 61) at p = 0.033; According to the data of SDS depressive symptoms in patients with IHD are more pronounced in comparison with patients with dilated cardiomyopathy U = 47 (p = 0.019)

Features of the Quasi-Static and Dynamic Magnetization Switching in NiO Nanoparticles: Manifestation of the Interaction between Magnetic Subsystems in Antiferromagnetic Nanoparticles

We report on the investigations of a system of 8-nm NiO particles representing antiferromagnetic (AFM) materials, which are weak magnetic in the form of submicron particles, but can be considered to be magnetoactive in the form of nanoparticles due to the formation of the uncompensated magnetic moment in them. The regularities of the behavior of magnetization switching in AFM nanoparticles are established by studying the magnetic hysteresis loops under standard quasi-static conditions and in a quasi-sinusoidal pulsed field of up to 130 kOe with pulse lengths of 4–16 ms. The magnetic hysteresis loops are characterized by the strong fields of the irreversible magnetization behavior, which is especially pronounced upon pulsed field-induced magnetization switching. Under the pulsed field-induced magnetization switching conditions, which are analogous to the dynamic magnetic hysteresis, the coercivity increases with an increase in the maximum applied field H0 and a decrease in the pulse length. This behavior is explained by considering the flipping of magnetic moments of particles in an external ac magnetic field; however, in contrast to the case of single-domain ferro- and ferrimagnetic particles, the external field variation rate dH/dt is not a universal parameter uniquely determining the coercivity. At the dynamic magnetization switching in AFM nanoparticles, the H0 value plays a much more important role. The results obtained are indicative of the complex dynamics of the interaction between different magnetic subsystems formed in AFM nanoparticle