Frequency-dependent reflection of spin waves from a magnetic inhomogeneity induced by a surface DC-current

The reflectivity of a highly localized magnetic inhomogeneity is experimentally studied. The inhomogeneity is created by a dc-current carrying wire placed on the surface of a ferrite film. The reflection of propagating dipole-dominated spin-wave pulses is found to be strongly dependent on the spin-wave frequency if the current locally increases the magnetic field. In the opposite case the frequency dependence is negligible.Comment: 3 pages, 3 figure

High-Temperature Behavior, Oxygen Transport Properties, and Electrochemical Performance of Cu-Substituted Nd1.6Ca0.4NiO4+δ Electrode Materials

In this study, Nd1.6Ca0.4Ni1−yCuyO4+δ-based electrode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) are investigated. Materials of the series (y = 0–0.4) are obtained by pyrolysis of glycerol-nitrate compositions. The study of crystal structure and high-temperature stability in air and under low oxygen partial pressure atmospheres are performed using high-resolution neutron and in situ X-ray powder diffraction. All the samples under the study assume a structure with Bmab sp.gr. below 350◦C and with I4/mmm sp.gr. above 500◦C. A transition in the volume thermal expansion coefficient values from 7.8–9.3 to 9.1–12.0 × 10−6, K−1 is observed at approximately 400◦C in air and 500◦C in helium.The oxygen self-diffusion coefficient values, obtained using isotope exchange, monotonically decrease with the Cu content increasing, while concentration dependence of the charge carriers goes through the maximum at x = 0.2. The Nd1.6Ca0.4Ni0.8Cu0.2O4+δ electrode materialdemonstrates chemical compatibility and superior electrochemical performance in the symmetrical cells with Ce0.8Sm0.2O1.9, BaCe0.8Sm0.2O3−δ, BaCe0.8Gd0.19Cu0.1O3−δ and BaCe0.5Zr0.3Y0.1Yb0.1O3−δ solid electrolytes, potentially for application in IT-SOFCs. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.122013100200-2; Ministry of Education and Science of the Russian Federation, Minobrnauka: AAAA-A21-121011390009-1; Ural Branch, Russian Academy of Sciences, UB RAS: 122020100324-3Material synthesis, sample preparation, and electrochemical studies were performed in the framework of budget tasks for the Institute of High Temperature Electrochemistry, UB RAS, project № 122020100324-3. The standard characterization of powder and ceramic materials was carried out at the Shared Access Centre “Composition of Compounds” of the Institute of High Temperature Electrochemistry, UB RAS. The synchrotron XRD experiments were performed at the shared research center SSTRC on the basis of the Novosibirsk VEPP-3 complex at BINP SB RAS. The in situ XRD study was carried out using the facilities of the shared research center “National Center of Investigation of Catalysts” at the Boreskov Institute of Catalysis (BIC). The part of the reported study concerning the crystal structure of the samples was funded within the framework of budget project for Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis.BIC support of the isotope exchange study by the Ministry of Science and Higher Education of the Russian Federation projects AAAA-A21-121011390009-1 and AAAA-A21-121011390007-7 is greatly acknowledged. XPS study of the electrode materials was partly performed in the framework of the budget task for the Institute of Metallurgy, UB RAS, project № 122013100200-2 using the equipment of the Shared Access Centre “Ural-M” of the Institute of Metallurgy, UB RAS.Acknowledgments: Material synthesis, sample preparation, and electrochemical studies were performed in the framework of budget tasks for the Institute of High Temperature Electrochemistry, UB RAS, project №122020100324-3. The standard characterization of powder and ceramic materials was carried out at the Shared Access Centre “Composition of Compounds” of the Institute of High Temperature Electrochemistry, UB RAS. The synchrotron XRD experiments were performed at the shared research center SSTRC on the basis of the Novosibirsk VEPP-3 complex at BINP SB RAS. The in situ XRD study was carried out using the facilities of the shared research center “National Center of Investigation of Catalysts” at the Boreskov Institute of Catalysis (BIC). The part of the reported study concerning the crystal structure of the samples was funded within the framework of budget project for Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis.BIC support of the isotope exchange study by the Ministry of Science and Higher Education of the Russian Federation projects AAAA-A21-121011390009-1 and AAAA -A21-121011390007-7 is greatly acknowledged. XPS study of the electrode materials was partly performed in the framework of the budget task for the Institute of Metallurgy, UB RAS, project № 122013100200-2 using the equipment of the Shared Access Centre “Ural-M” of the Institute of Metallurgy, UB RAS

Influence of Gamma-Ray Emission on the Isotopic Composition of Clouds in the Interstellar Medium

We investigate one mechanism of the change in the isotopic composition of cosmologically distant clouds of interstellar gas whose matter was subjected only slightly to star formation processes. According to the standard cosmological model, the isotopic composition of the gas in such clouds was formed at the epoch of Big Bang nucleosynthesis and is determined only by the baryon density in the Universe. The dispersion in the available cloud composition observations exceeds the errors of individual measurements. This may indicate that there are mechanisms of the change in the composition of matter in the Universe after the completion of Big Bang nucleosynthesis. We have calculated the destruction and production rates of light isotopes (D, 3He, 4He) under the influence of photonuclear reactions triggered by the gamma-ray emission from active galactic nuclei (AGNs). We investigate the destruction and production of light elements depending on the spectral characteristics of the gamma-ray emission. We show that in comparison with previous works, taking into account the influence of spectral hardness on the photonuclear reaction rates can increase the characteristic radii of influence of the gamma-ray emission from AGNs by a factor of 2-8. The high gamma-ray luminosities of AGNs observed in recent years increase the previous estimates of the characteristic radii by two orders of magnitude. This may suggest that the influence of the emission from AGNs on the change in the composition of the medium in the immediate neighborhood (the host galaxy) has been underestimated.Comment: 13 pages, 13 figures, 3 table

Femtometer Toroidal Structures in Nuclei

The two-nucleon density distributions in states with isospin $T=0$, spin $S$=1 and projection $M_S$=0 and $\pm$1 are studied in $^2$H, $^{3,4}$He, $^{6,7}$Li and $^{16}$O. The equidensity surfaces for $M_S$=0 distributions are found to be toroidal in shape, while those of $M_S$=$\pm$1 have dumbbell shapes at large density. The dumbbell shapes are generated by rotating tori. The toroidal shapes indicate that the tensor correlations have near maximal strength at $r<2$ fm in all these nuclei. They provide new insights and simple explanations of the structure and electromagnetic form factors of the deuteron, the quasi-deuteron model, and the $dp$, $dd$ and $\alpha d$ $L$=2 ($D$-wave) components in $^3$He, $^4$He and $^6$Li. The toroidal distribution has a maximum-density diameter of $\sim$1 fm and a half-maximum density thickness of $\sim$0.9 fm. Many realistic models of nuclear forces predict these values, which are supported by the observed electromagnetic form factors of the deuteron, and also predicted by classical Skyrme effective Lagrangians, related to QCD in the limit of infinite colors. Due to the rather small size of this structure, it could have a revealing relation to certain aspects of QCD.Comment: 35 pages in REVTeX, 25 PostScript figure

МЕТОДИЧЕСКИЕ ПОДХОДЫ К ЭКСПЕРИМЕНТАЛЬНОМУ ТЕСТИРОВАНИЮ РЕЗИСТЕНТНОСТИ КЛЕТОК ОПУХОЛИ ЧЕЛОВЕКА К ХИМИОТЕРАПИИ

The purpose of the study was to analyze the existing methodological approaches to the experimental testing of resistance to chemotherapy and assess the prospects for their further application.Material and Methods. We analyzed publications regarding the experimental testing of tumor resistance to chemotherapy available in the databases, such as SciVerse Scopus (748), PubMed (1727), Web of Science (1025), RSCI (125). To obtain fulltext publications, the electronic resources of Research Gate, RSCI, CyberLenink were used. Forty-two modern publications (2012–19) including 18 articles of the founders of the methods analyzed in the review were cited.Results. The review discusses the characteristics of the main methods for assessing the resistance / sensitivity of tumor cells obtained from biopsy / surgical specimens to various chemotherapy drugs in vitro in monolayer and suspension cultures, in the form of spheroids, histo and organocultures, as well as in vivo xenografts of tumors in immunodeficient mice. During testing, the proliferative and metabolic activities as well as the level of cell death were considered as the main evaluated characteristics of tumor cells. The main indicators were the intensity of DNA synthesis, the level of protein or ATP in the cell, the activity of NADH-dehydrogenases, the level of apoptosis, and the integrity of cell structures. The advantages and disadvantages of the described methods, as well as the prospects for their further application were discussed.Conclusion. Over the past half century of using the experimental testing of tumor cell resistance in order to personalize chemotherapeutic treatment, the evolution of methodological approaches was based on the increase in their safety and sensitivity through the use of fluorescent compounds. The general vector for improving experiments on the personalization of tumor chemotherapy is aimed at approximating the experimental conditions to the processes occurring in the human body. Each of these methods has its own range of predictive power and, if used properly, can provide a useful guide for treatment. Цель исследования – анализ существующих методических подходов к экспериментальному тестированию резистентности к химиотерапии и оценка перспектив их дальнейшего применения.Материал и методы. При подготовке обзора были проанализированы статьи по теме экспериментального тестирования резистентности опухоли к химиопрепаратам, имеющиеся в информационных базах биомедицинской литературы SciVerse Scopus (748), PubMed (1727), Web of Science (1025), РИНЦ (125). Для получения полнотекстовых документов были использованы электронные ресурсы Research Gate, РИНЦ, КиберЛенинка. В тексте обзора были процитированы 42 современные публикации (2012–19 гг.), а также 18 статей основоположников методик, анализируемых в обзоре, которые используются и в наши дни.Результаты. В обзоре рассмотрены особенности основных методов оценки резистентности/чувствительности опухолевых клеток, получаемых из биопсийного/операционного материала к различным химиопрепаратам при их культивировании in vitro в монослое и суспензионных культурах, в виде сфероидов, гисто- и органокультур, а также при получении in vivo ксенографтов опухоли на иммунодефицитных мышах. При тестировании в качестве основных оцениваемых характеристик опухолевых клеток рассматриваются пролиферативная и метаболическая активность, уровень клеточной гибели. При этом основными показателями выступают интенсивность синтеза ДНК, уровень белка или АТФ в клетке, активность NADН-дегидрогеназ, уровень апоптоза, целостность клеточных структур. Обсуждены преимущества и недостатки описываемых методов, а также перспективы их дальнейшего применения.Заключение. За прошедшие полвека использования экспериментального тестирования резистентности опухолевых клеток в целях персонализации химиотерапевтического лечения произошедшая эволюция методических подходов заключалась в повышении безопасности их проведения и чувствительности за счет использования флуоресцентных соединений. Общий вектор совершенствования экспериментов по персонализации химиотерапии опухолей направлен на приближение условий эксперимента к процессам, происходящим в организме человека. Каждый из этих методов имеет свой диапазон предсказательной силы и при адекватном использовании может дать полезный ориентир для лечения

Противоопухолевая активность кураксина CBL0137 на моделях острых лейкозов in vitro

Background. Curaxin CBL0137 is a novel non-genotoxic compound with anti-cancer activity based on CBL0137 ability of non-covalent interaction with DNA causing histone chaperone FACT relocation. Anti-cancer activity of this drug was demonstrated previously on the wide panel of solid cancer models in vitro and in vivo.Objectives. Estimation of anticancer effects of CBL0137 on the acute myeloblastic leukemia cells (THP-1) and acute lymphoblastic leukemia (CCRF-CEM).Materials and methods. CBL0137 cytotoxicity was analyzed using the MTT test, the effects on the cell cycle and the induction of apoptosis was assessed by flow cytometry, the activity of signaling pathways in cells treated with CBL0137 was determined by real-time polymerase chain reaction.Results. Cell treatment with CBL0137 led to cell cycle arrest and apoptosis induction. In the study of CBL0137 effect on target gene clusters of 10 signal transduction pathways involved in the pathogenesis of acute leukemia we have showed that CBL0137 inhibited the expression of down-stream genes of WNT and Hedgehog signaling in both cell lines. In THP-1 cells we also observed the inhibition of the expression of PPARγ target and hypoxia-activated genes. In CCRF-CEM cells CBL0137 also induced the expression of Notch signaling target genes.Conclusion. The antitumor activity of CBL0137 was demonstrated on acute leukemia cell cultures, the drug possesses cytotoxicity, causes cell cycle arrest and activation of apoptosis. Significant changes in the expression of efferent gene clusters of several signaling pathways were observed in the cells treated with CBL0137.Введение. Кураксин CBL0137 – новое негенотоксичное соединение, обладающее противоопухолевой активностью, в основе которой лежит способность препарата нековалентно взаимодействовать с ДНК, вызывая транслокацию гистонового шаперона FACT в хроматиновую фракцию. Ранее противоопухолевая активность этого агента была продемонстрирована относительно широкого спектра солидных опухолей in vitro и in vivo.Цель исследования – изучение противоопухолевой активности CBL0137 в отношении клеток острого миелобластного лейкоза (THP-1) и острого лимфобластного лейкоза (CCRF-CEM) in vitro.Материалы и методы. Для определения цитотоксичности CBL0137 использовали МТТ-тест, влияние на клеточный цикл и индукцию апоптоза оценивали с помощью проточной цитофлуориметрии, активность функционирования сигнальных путей при действии на клетки CBL0137 определяли с помощью полимеразной цепной реакции в реальном времени.Результаты. Обработка клеток CBL0137 приводит к аресту клеточного цикла и активации апоптоза. При исследовании влияния CBL0137 на кластеры таргетных генов 10 сигнальных путей, вовлеченных в онкогенез острых лейкозов, его ингибирующее действие было выявлено для сигнальных путей WNT и Hedgehog в обеих клеточных линиях. В клеточной линии THP-1 также наблюдалось ингибирование эфферентных генов PPARγ и генов, активирующихся при гипоксии. В клетках CCRF-CEM при действии CBL0137, кроме того, наблюдалось усиление экспрессии всех исследованных таргетных генов сигнального пути Notch.Заключение. На культурах клеток острых лейкозов продемонстрирована противоопухолевая активность CBL0137, препарат обладает цитотоксичностью, вызывает арест клеточного цикла и активацию апоптоза. При действии CBL0137 наблюдаются значительные изменения в экспрессии кластеров эфферентных генов сразу нескольких сигнальных путей

Влияние ДНК-тропных антиканцерогенных соединений на механизмы регуляции экспрессии генов

The presented review is devoted to the analysis of molecular mechanisms of action for different natural DNA-tropic compounds with established tumor preventive activity. Here we present their cancer preventive effects observed in vivo, mechanisms of DNA binding, influence on epigenetic regulation and “housekeeping” protein function. Additionally, the influence of these compounds on DNA helix parameters is discussed that should impact on epigenetic regulation of gene expression and formation of topologically associated domains.Обзор посвящен анализу молекулярных механизмов действия ряда природных ДНК-тропных соединений с установленной антиканцерогенной активностью. Приведены данные исследований антиканцерогенного действия этих соединений в экспериментах in vivo, рассмотрены механизмы их связывания с ДНК, влияния на метилирование ДНК и модификацию гистонов, способность к ингибированию функций ферментов «домашнего хозяйства». Кроме того, проанализированы возможные эффекты этих соединений на характеристики дуплекса ДНК, что должно иметь значение для эпигенетической регуляции экспрессии генов и формирования топологически ассоциированных доменов

Определение химиорезистентности клеток рака яичников in vitro

Objectives: to provide a rationale for existing approaches for the evaluation of chemoresistance of ovarian cancer in vitro, to perform a comparative analysis of the methods and to assess the perspectives of their further application.Materials and methods. For the review preparation, we analyzed articles on experimental testing of ovarian cancer resistance to chemotherapeutic agents, available at biomedical literature databases SciVerse Scopus (158), PubMed (323), Web of Science (285), RSCI (64). The review cited 37 recent publications, 12 of them being published over the past three years, and 16 articles being referred as pioneer publications on techniques previously and used today.Results. Peculiarities of the main methods for assessing the resistance and sensitivity of a cancer to various chemotherapeutic drugs using primary cultures of tumor cells obtained from biopsy or surgical material are analyzed. Proliferative and metabolic activities as well as the level of cell death were considered as the main evaluated characteristics of tumor cells. The methodological features of the described methods are discussed, as well as the prospects for their further application.Conclusion. Predictive detection of chemoresistance of ovarian cancer is based on testing the viability of tumor cells in the presence of a chemotherapeutic drug. The results of studies of the key mechanisms of chemoresistance development in tumor cells provide the rationale for improving in vitro testing.Цель исследования – представить обоснование существующих подходов к тестированию химиорезистентности рака яичников in vitro, провести их сравнительный анализ и дать оценку перспектив их дальнейшего применения.Материалы и методы. При подготовке обзора были проанализированы статьи по теме прогнозного определения химиорезистентности рака яичников к химиотерапевтическим препаратам, имеющиеся в информационных базах биомедицинской литературы SciVerse Scopus (158), PubMed (323), Web of Science (285), РИНЦ (64). В обзоре процитированы 37 современных публикаций, 12 работ из которых были опубликованы в течение последних 3 лет, а 16 статей относятся к первым публикациям по разработанным методикам, которые продолжают использовать в наши дни.Результаты. Рассмотрены особенности основных методов оценки резистентности / чувствительности рака яичников к различным химиотерапевтическим препаратам с использованием первичных культур опухолевых клеток, получаемых из биопсийного / операционного материала. При тестировании в качестве основных оцениваемых характеристик опухолевых клеток рассмотрены пролиферативная и метаболическая активность, а также уровень клеточной гибели. Обсуждены методические особенности описываемых методов, а также перспективы их дальнейшего применения.Заключение. Прогнозное выявление химиорезистентности рака яичников проводится на основании тестирования жизнеспособности опухолевых клеток в присутствии химиотерапевтического препарата. Обоснованием для совершенствования такого тестирования in vitro служат результаты исследований ключевых механизмов развития химиорезистентности опухолевых клеток