Lanthanoid-doped quaternary garnets as phosphors for high brightness cathodoluminescence-based light sources

Gadolinium-yttrium- aluminum-gallium garnets (GYAGG) doped and codoped with Eu, Tb, and Ce were manufactured as ceramics to develop long-wavelength phosphors for high-brightness white light sources based on cathodoluminescence (CL). The CL light yield (LY) of Tb-doped ceramics at high-intensity electron beam excitation is shown to be more than twice as high as that of the conventional phosphor YAG:Ce, whereas codoping with Eu to redshift the chromaticity results in reducing the LY approximately to the level of YAG:Ce. The LY might be substantially improved by using a mix of Tb- and Eu-doped GYGAG powders instead of a single codoped GYGAG to produce ceramic phosphor. The high LY is explained by favorable contribution of Gd sublattice in excitation transfer to activator ions. Chromaticity of phosphors GYGAG:Tb, Eu can be tuned in a wide range by varying the ratio of Tb to Eu concentration. They are radiation resistant and stabile in the temperature range from 300 to 450 K. © 2022 The Author(s)Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-11-2021-070, 075-15-2021-1353, FEUZ-2020-0060This work was supported by the Ministry of Science and Higher Education of the Russian Federation (FEUZ-2020-0060, No. 075-15-2021-1353 & 075-11-2021-070)

Towards effective indirect radioisotope energy converters with bright and radiation hard scintillators of (Gd,Y)3Al2Ga3O12 family

Ceramics of quaternary garnets (Gd,Y)3Al2Ga3O12 doped with Ce, Tb have been fabricated and evaluated as prospective materials for indirect energy converters of α-and β-voltaic. Samples were characterized at excitation with an X-ray source and an intense 150 keV electron beam and showed good temperature stability of their emission and tolerance to irradiation. The role of X-rays accompanied the α-particle emitting in the increase of the conversion efficiency is clarified. The garnet-type structure of the matrix in the developed materials allows the production of quality crystalline mass with a light yield exceeding that of the commonly used YAG: Ce scintillator by a factor of two times. © 2022 Korean Nuclear SocietyMinistry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2021-1353, FEUZ-2020-0060; Ministerstwo Edukacji i Nauki, MNiSW: 075-11-2021-070; Ministry of Science and Higher Education of the Russian FederationAuthors with affiliations b, d, e and f acknowledge support from Russian Ministry of Science and Education grant No. 075-15-2021-1353 . The scientific equipment provided by shared research facilities “Scientific Research Analytical Center of National Research Center “Kurchatov Institute” – IREA” was used, with financial support of Russian Federation, represented by the Ministry of Science and Higher Education, agreement No. 075-11-2021-070 dated August 19, 2021. The work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, project No. FEUZ-2020-0060 ) (authors with affiliation “c”).Authors with affiliations b, d, e and f acknowledge support from Russian Ministry of Science and Education grant No. 075-15-2021-1353. The scientific equipment provided by shared research facilities “Scientific Research Analytical Center of National Research Center “Kurchatov Institute” – IREA” was used, with financial support of Russian Federation, represented by the Ministry of Science and Higher Education, agreement No. 075-11-2021-070 dated August 19, 2021. The work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, project No. FEUZ-2020-0060) (authors with affiliation “c”)

МЕТОД ПОЛУЧЕНИЯ ПРОИЗВОДНОГО КЛОЗО-ДЕКАБОРАТНОГО АНИОНА С ПЕНДАНТНОЙ DTPA-ГРУППОЙ

This paper describes the method for obtaining a new derivative of the closo-decaborate anion with diethylenetriaminepentaacetic acid (DTPA) as a pendant group attached to the boron cluster through an alkoxyl spacer chain. This derivative is formed by the interaction of 1,4-dioxane derivative of the anion [B10H10]2- with DTPA potassium salt in an aqueous medium. As a result of the reaction, an exo-polyhedral cyclic substituent is opened, and then the addition of a polyfunctional group through an oxygen atom occurs. The synthesized compound is in fact an effective polydentate ligand capable of coordinating to the complexing agent both due to the donor atoms of the attached DTPA fragment and through the formation of three-center two-electron bonds. The obtained compound interacts with gadolinium(III) carbonate forming a complex of the composition [Gd2B10H9O2C4H8(dtpa)]·3H2O. The synthesized substances were studied by IR spectroscopy, polynuclear (11B, 13C and 1H) NMR spectroscopy, ESI mass spectrometry, elemental and thermographic analysis. closo-Decaborate with the pendant DTPA group is of interest in 10B neutron capture therapy of malignant tumors due to the high content of boron atoms and a convenient way of their transport to the affected cells. The obtained boron-containing derivatives of gadolinium(III) can act as drugs of combined action, because they can perform, in addition to the above described therapeutic function, the diagnostic function due to the presence of gadolinium atoms int hem.В статье описан метод получения нового производного клозо-декаборатного аниона с диэтилентриаминпентауксусной кислотой (DTPA) в качестве пендантной группы, присоединенной к борному кластеру через алкоксильную спейсерную цепочку. Оно образуется при взаимодействии 1,4-диоксанового производного аниона [B10H10]2- с калийной солью DTPA в водной среде. В результате реакции происходит раскрытие экзо-полиэдрического циклического заместителя с последующим присоединением полифункциональной группы через атом кислорода. Синтезированное соединение по сути является эффективным полидентатным лигандом, способным координироваться к комплексообразователю как за счет донорных атомов присоединенного фрагмента DTPA, так и посредством образования трехцентровых двухэлектронных связей. Полученное соединение вступает во взаимодействие с карбонатом гадолиния(III), образуя комплекс состава [Gd2(B10H9O2C4H8(dtpa))]‧3H2O. Синтезированные вещества исследованы методами ИК-спектроскопии, полиядерной (11B, 13C и 1H) ЯМР-спектроскопии, ESI-масс-спектрометрии, элементного и термографического анализа. клозо-Декабораты с пендантной DTPA-группой представляют интерес для 10B-нейтронозахватной терапии злокачественных опухолей благодаря высокому содержанию атомов бора и удобному способу их транспорта к пораженным клеткам. Полученные борсодержащие производные гадолиния(III) могут выступать в качестве препаратов сочетанного действия, так как помимо вышеописанной терапевтической функции способны выполнять и диагностическую - за счет наличия в них атомов гадолиния

Перспектива применения биогенных квантовых точек наночастиц сульфидов серебра, кадмия и цинка для создания полимерных бионанокомпозитных материалов

The possibility of applying silver, cadmium and zinc sulfide nanoparticles (npAg2S, npCdS and npZnS) obtained using Shewanella oneidensis MR-1 and Bacillus subtilis 168 bacterial cultures for the creation of a new class of polymeric bionanocomposite materials was investigated. Biogenic nanoparticles obtained in aqueous solutions of the corresponding salts in the presence of various types of microorganisms are characterized by the presence of protein molecules on their surface. The molecules composition is determined by the bacterial culture. Proteins stabilize them and allow the nanoparticles to covalently join the active groups of polymeric carriers. Aminated chloromethylated polystyrene microspheres, as well as ion-exchange resins of various types, were used as polymeric matrices. Analysis of interaction with them can be used as a method for studying the properties of biogenic nanoparticles of metal sulfides for subsequent successful selection of a polymeric carrier. The immobilization of biogenic nanoparticles of metal sulfides onto the surface of aminated chloromethylated polystyrene microspheres was found to depend on the level of stability of aqueous nanoparticle suspensions and is determined by the negative charge of biogenic npAg2S, npCdS and npZnS, which suggests covalent binding and the electrostatic interaction of the components in the composition of the polymer bionanocomposite. A comparative analysis of the parameters of nanoparticles depending on the strain used in the biosynthesis was carried out. Analysis of the main physicochemical characteristics of npCdS and npZnS showed that the small size of nanoparticles (npCdS - 5 nm, npZnS - up to 2 nm) and the presence of luminescence peaks at wavelengths less than 400 nm classify them in the blue region of the fluorescence spectrum and identify them as quantum dots. Thus, the possibility of introducing fluorescent quantum dots of nanoparticles of metal sulfides of biogenic origin into various polymeric matrices has been demonstrated, which contributes to the expansion of the horizons for using a new class of nanoparticles to create polymeric bionanocomposites.Исследована возможность применения наночастиц сульфида серебра, кадмия и цинка (npAg2S, npCdS и npZnS), полученных с использованием бактериальных культур Shewanella oneidensis MR-1 и Bacillus subtilis 168, для создания нового класса полимерных бионанокомпозитных материалов. Биогенные наночастицы, полученные в водных растворах соответствующих солей в присутствии различных типов микроорганизмов, характеризуются наличием на их поверхности белковых молекул, состав которых определяется бактериальной культурой. Белки стабилизируют наночастицы и позволяют им ковалентно присоединяться к активным группам полимерных носителей. В качестве полимерных матриц использовали аминированные хлорм,етилирован-ные полистирольные микросферы, а также ионообменные смолы различных типов. Анализ взаилюдействия с ними люжет быть использован в качестве лъетода изучения свойств биогенных наночастиц сульфидов металлов для последующего успешного выбора полимерного носителя. Установлено, что иммобилизация биогенных наночастиц сульфидов металлов на поверхности аминированных хлорметилированных полистирольных микросфер зависит от уровня стабильности водных суспензий наночастиц и определяется отрицательным зарядом биогенных npAg2S, npCdS и npZnS, что предполагает ковалентное связывание и электростатическое взаимодействие компонентов в составе полимерного бионанокомпозита. Проведен сравнительный анализ параметров наночастиц в зависимости от штамма, используемого в биосинтезе. Анализ основных физико-химических характеристик npCdS и npZnS показал, что небольшие размеры наночастиц (npCdS - 5 нм, npZnS - до 2 нм) и наличие люминесцентных пиков на длинах волн менее 400 нм, что относит их к синей области спектра флуоресценции, позволяет классифицировать их как квантовые точки. Таким образом, была продемонстрирована возможность введения флуоресцентных квантовых точек наночастиц сульфидов металлов биогенного происхождения в различные полимерные матрицы, что способствует расширению горизонтов использования нового класса наночастиц для создания полимерных бионанокомпозитов

Определение происхождения природного битума в мумифицирующих смолах древнеегипетских мумий из собрания ГМИИ им. А.С. Пушкина

This work presents the results of a study of the resins of seven Ancient Egyptian mummies from the collection of the Pushkin State Museum of Fine Arts using a complex of analytical methods: gas chromatography, atomic emission and mass spectrometry. Natural bitumen and beeswax were identified in the resins using the gas chromatography–mass spectrometry method. Based on the results of hydrocarbon distribution in the profiles of n-alkanes in the resin coatings of the mummies and naturally occurring bitumen, it was assumed that the Dead Sea bitumen was used. The gas chromatography–mass spectrometry studies of mummy resins in the selected ion mode (m/z 217 and 191) provided additional evidence of the bitumen’s geographic origin. Atomic emission spectrometry with inductively coupled plasma was used as a means to determine the content of microelements. Vanadium, nickel and molybdenum were found in the tar of five mummies. The determined relative amounts of vanadium, nickel, and molybdenum in the resins of the studied mummies showed a good correlation with the available data on the content of these elements in the Dead Sea bitumen, as well as the Fayum mummy resin based on this bitumen. The advantages of using the method of identifying bitumen in mummy resins based on relative content of vanadium, nickel, and molybdenum were revealed.В работе представлены результаты исследования составов смол семи древнеегипетских мумий из коллекции Государственного музея изобразительных искусств имени А.С. Пушкина с применением комплекса аналитических методов: газовой хроматографии (ГХ), атомно-эмиссионной и масс-спектрометрии (МС). Методом ГХ–МС в них идентифицированы природный битум и пчелиный воск. По результатам распределений углеводородов в профилях н-алканов в смоляных покрытиях мумий и природных битумов высказано предположение об использовании битума Мертвого моря. Дополнительные доказательства географического происхождения битума получены ГХ–МС-исследованием смол мумий в режиме мониторинга заданных ионов (m/z 217 и 191). Методом атомно-эмиссионной спектрометрии с индуктивно связанной плазмой определено содержание микроэлементов и показано, что в смолах пяти мумий присутствуют ванадий, никель и молибден. Полученные результаты свидетельствуют об удовлетворительной корреляции их с литературными данными по содержанию указанных элементов в битуме Мертвого моря и смоле Фаюмской мумии на основе этого битума. Выявлены преимущества использования метода идентификации битума в смолах мумий по относительному содержанию ванадия, никеля и молибдена

Prospects of Applying Biogenic Quantum Dots of Silver, Cadmium and Zinc Sulfides Nanoparticles to Create Polymeric Bionanocomposite Materials

The possibility of applying silver, cadmium and zinc sulfide nanoparticles (npAg2S, npCdS and npZnS) obtained using Shewanella oneidensis MR-1 and Bacillus subtilis 168 bacterial cultures for the creation of a new class of polymeric bionanocomposite materials was investigated. Biogenic nanoparticles obtained in aqueous solutions of the corresponding salts in the presence of various types of microorganisms are characterized by the presence of protein molecules on their surface. The molecules composition is determined by the bacterial culture. Proteins stabilize them and allow the nanoparticles to covalently join the active groups of polymeric carriers. Aminated chloromethylated polystyrene microspheres, as well as ion-exchange resins of various types, were used as polymeric matrices. Analysis of interaction with them can be used as a method for studying the properties of biogenic nanoparticles of metal sulfides for subsequent successful selection of a polymeric carrier. The immobilization of biogenic nanoparticles of metal sulfides onto the surface of aminated chloromethylated polystyrene microspheres was found to depend on the level of stability of aqueous nanoparticle suspensions and is determined by the negative charge of biogenic npAg2S, npCdS and npZnS, which suggests covalent binding and the electrostatic interaction of the components in the composition of the polymer bionanocomposite. A comparative analysis of the parameters of nanoparticles depending on the strain used in the biosynthesis was carried out. Analysis of the main physicochemical characteristics of npCdS and npZnS showed that the small size of nanoparticles (npCdS - 5 nm, npZnS - up to 2 nm) and the presence of luminescence peaks at wavelengths less than 400 nm classify them in the blue region of the fluorescence spectrum and identify them as quantum dots. Thus, the possibility of introducing fluorescent quantum dots of nanoparticles of metal sulfides of biogenic origin into various polymeric matrices has been demonstrated, which contributes to the expansion of the horizons for using a new class of nanoparticles to create polymeric bionanocomposites

THE METHOD FOR OBTAINING A DERIVATIVE CLOSO-DECABORATE ANION WITH PENDANTE DTPA-GROUP

This paper describes the method for obtaining a new derivative of the closo-decaborate anion with diethylenetriaminepentaacetic acid (DTPA) as a pendant group attached to the boron cluster through an alkoxyl spacer chain. This derivative is formed by the interaction of 1,4-dioxane derivative of the anion [B10H10]2- with DTPA potassium salt in an aqueous medium. As a result of the reaction, an exo-polyhedral cyclic substituent is opened, and then the addition of a polyfunctional group through an oxygen atom occurs. The synthesized compound is in fact an effective polydentate ligand capable of coordinating to the complexing agent both due to the donor atoms of the attached DTPA fragment and through the formation of three-center two-electron bonds. The obtained compound interacts with gadolinium(III) carbonate forming a complex of the composition [Gd2B10H9O2C4H8(dtpa)]·3H2O. The synthesized substances were studied by IR spectroscopy, polynuclear (11B, 13C and 1H) NMR spectroscopy, ESI mass spectrometry, elemental and thermographic analysis. closo-Decaborate with the pendant DTPA group is of interest in 10B neutron capture therapy of malignant tumors due to the high content of boron atoms and a convenient way of their transport to the affected cells. The obtained boron-containing derivatives of gadolinium(III) can act as drugs of combined action, because they can perform, in addition to the above described therapeutic function, the diagnostic function due to the presence of gadolinium atoms int hem

Albumin-Functionalized Iron Oxide Nanoparticles for Theranostics: Engineering and Long-Term In Situ Imaging

Magnetic nanosystems (MNSs) consisting of magnetic iron oxide nanoparticles (IONPs) coated by human serum albumin (HSA), commonly used as a component of hybrid nanosystems for theranostics, were engineered and characterized. The HSA coating was obtained by means of adsorption and free radical modification of the protein molecules on the surface of IONPs exhibiting peroxidase-like activity. The generation of hydroxyl radicals in the reaction of IONPs with hydrogen peroxide was proven by the spin trap technique. The methods of dynamic light scattering (DLS) and electron magnetic resonance (EMR) were applied to confirm the stability of the coatings formed on the surface of the IONPs. The synthesized MNSs (d ~35 nm by DLS) were intraarterially administered in tumors implanted to rats in the dose range from 20 to 60 μg per animal and studied in vivo as a contrasting agent for computed tomography. The long-term (within 14 days of the experiment) presence of the MNSs in the tumor vascular bed was detected without immediate or delayed adverse reactions and significant systemic toxic effects during the observation period. The peroxidase-like activity of MNSs was proven by the colorimetric test with o-phenylenediamine (OPD) as a substrate. The potential of the synthesized MNSs to be used for theranostics, particularly, in oncology, was discussed