Dynamics of photogenerated charge carriers in TiO2 /MoO3, TiO2 /WO3 and TiO2 /V2O5 photocatalysts with mosaic structure

Titania is a widely used photocatalytic material possessing such advantages as low cost and high reactivity under the ultraviolet light illumination. However, the fast recombination of photoexcited charge carriers limits its application. Herein, we have synthesized original nanomaterials with mosaic structures that exhibited well-defined heterojunctions and new properties. Using SEM, XRD, EPR spectroscopy, photocatalytic measurements, and photoinduced pathphysiological activity of these photocatalysts, we studied the processes of charge carrier accumulation in TiO2 /MoO3, TiO2 /WO3, and TiO2 /V2 O5 under in situ UV illumination with emphasis on the charge exchange between energy levels of these nanosized semiconductors. It is shown that the accumulation of photoinduced charges occurs in two forms (i) filled electron traps corresponding to Ti4+ /Ti3+ levels and (ii) Mo5+ centers, both forms contributing to the photoinduced biocide activity of the samples. This work demonstrates that light exposure of heterostructure photocatalysts with mosaic surfaces produces different types of charge-trapping centers capable of interacting with molecular oxygen yielding peroxo species, which provide long-life light-induced ”self-cleaning” behavior. Such photoaccumulating materials open new opportunities in developing light-driven self-sterilization structures exhibiting a prolonged bactericidal effect up to 10 h after stopping light exposure. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Spin Density Distribution in a Nitroxide Biradical Containing 13C-Enriched Acetylene Groups in the Bridge: DFT Calculations and EPR Investigation

Abstract A specially synthesized nitroxide biradical R6-13C:C-p-C6H4–C:13CR6,B3, where R6 = 1-oxyl-2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridine nitroxide, has been studied by electron paramagnetic resonance spectroscopy, and electron-nuclear double resonance (ENDOR). Spin density distribution and hyperfine splitting (hfs) constant on 13C atoms calculations for biradical B3 were carried out using B3LYP and PBE0 functionals and several different basis sets including N07 family and were compared with the experimental value of the hfs constant on 13C atoms, measured from ENDOR spectra of B3. The mechanism of the intramolecular electron spin exchange in B3 biradical is discussed

Comparison of Mathematical Methods for Compensating a Current Signal Under Current Transformers Saturation Conditions

Current measurements from electromagnetic current transformers are essential for the construction of secondary circuit systems, including for protection systems. Magnetic core of these transformers are at risk of saturation, as a result of which maloperation of protection algorithms can possibly occur. The paper considers methods for recovering a current signal in the saturation mode of current transformers. The advantages and disadvantages of methods for detecting the occurrence of current transformers core saturation are described. A comparative analysis of mathematical methods for recovering a current signal is given, their approbation was carried out, and the most promising of them was revealed. The stability and sensitivity of recovery methods were tested by adding white noise to the measured signal and taking into account the initial flux density (remanent magnetization) in the current transformers core. Their comparison is given on the basis of angular, magnitude, and total errors at a given simulation interval. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This work was supported in part by the International Cooperation Project of National Natural Science Foundation of China under Grant 41761144079, in part by the Strategic Priority Research Program of the Chinese Academy of Sciences, in part by the Pan-Third Pole Environment Study for a Green Silk Road under Grant XDA20060303, in part by the K. C.Wong Education Foundation under Grant GJTD-2020-14, in part by the CAS PIFI Fellowship under Grant 2021PC0002, in part by the Xinjiang Tianchi Hundred Talents Program under Grant Y848041, in part by the CAS Interdisciplinary Innovation Team under Grant JCTD-2019-20, in part by the project of the Research Center of Ecology and Environment in Central Asia under Grant Y934031, and in part by the Regional Collaborative Innovation Project of Xinjiang Uygur Autonomous Regions under Grant 2020E01010

Шкала GRACE 2.0 для прогнозирования течения острого коронарного синдрома: какой из маркеров повреждения миокарда использовать?

Aim. To compare the effectiveness of various markers of myocardial injury (creatine phosphokinase MB-fraction (CK-MB), cardiac troponin I, measured by standard and high sensitivity methods (cTnI and hs-TnI), and heart-type fatty acids binding protein (H-FABP)) in predicting the ACS course using the GRACE 2.0 score.Methods. 183 patients with a verified diagnosis of ACS were included in the study. The levels of CK-MB, cTnl, hs-Tnl and H-FABP were measured at admission. Qualitative assessment of H-FABP was performed by immunochromatographic express-tests “CARD-INFO” and “CardioFABP”. Risk assessment of death in the in-hospital period and within the 12-months follow-up period, as well as death and/or acute myocardial infarction (AMI) within the 12-months follow-up was estimated using the GRACE 2.0 score with alternate inclusion of the various cardiomarkers. The effectiveness of the resultant prognostic scales was evaluated using the ROC-analysis and comparison of the areas under the curve (AUC).Results. 114 patients (62.3%) were diagnosed with AMI and 69 (37.7%) with unstable angina. 10 patients (5.5%) died during the indexed hospitalization. Four patients died within the follow-up and 8 patients (4.4%) had Ami. 94 patients (51.3%) had elevated hs-Tnl levels at admission, 90 patients (49.2%) - cTnl, 45 patients (24.6%) - CK-MB. H-FABP levels were elevated in 70 (38.3%). The express-test “CARD-INFO” was positive in 86 patients (47.0%), the “CardioFABP” - in 125 (68.3%). There were no significant differences found between the stratification of ACS patients by the GRACE 2.0 score into high and non-high risk groups in terms of complications (p<0.05). Similarly, there were no significant differences found between the AUC values of the cardiomarkers in terms of developing the endpoints using the GRACE 2.0 score (p<0.05).Conclusion. The introduction of H-FABP in the GRACE 2.0 scale is non-inferior to traditional markers of myocardial damage and may be used to stratify risk in patients with ACS.Цель. Сравнить эффективность прогнозирования течения острого коронарного синдрома (ОКС) с помощью шкалы GRACE 2.0 при включении в нее результатов определения различных маркеров повреждения миокарда (МВ-фрак-ции креатинфосфокиназы (МВ-КФК), сердечного тропонина I, определенного методами стандартной и высокой чувствительности (сТн I и вчТн I), и сердечного белка, связывающего жирные кислоты (сБСЖК)).Материалы и методы. В исследование включены 183 пациента с верифицированным диагнозом «ОКС». Больным при поступлении проводилось количественное определение уровня МВ-КФК, сТн I, вчТн I и сБСЖК, а также качественная оценка содержания сБСЖК с помощью иммунохроматографических экспресс-тестов «КАРД-ИНФО» и «КардиоБСЖК». Оценку риска летального исхода в стационаре и в течение 12 месяцев наблюдения, а также летального исхода и/или развития острого инфаркта миокарда (ОИМ) в течение 12 месяцев, выполняли с помощью шкалы GRACE 2.0 с поочередным использованием результатов определения различных кардиомаркеров. Эффективность полученных прогностических шкал оценивали с помощью ROC-анализа и сопоставления показателей площади под кривой (AUC).Результаты. У 114 больных (62,3%) диагностирован ОИМ, у 69 (37,7%) - нестабильная стенокардия. В течение госпитализации умерли 10 пациентов (5,5%), в течение последующего наблюдения произошло еще 4 летальных исхода и 8 случаев (4,4%) развития ОИМ. Уровень вчТн I при поступлении был повышен у 94 пациентов (51,3%), сТн I - у 90 (49,2%), МВ-КФК - у 45 (24,6%), сБСЖК, определенного количественным методом, - у 70 (38,3%). Экспресс-тест «КАРД-ИНФО» был положительным у 86 пациентов (47,0%), «КардиоБ-СЖК» - у 125 (68,3%). Результаты распределения больных ОКС на группы высокого и невысокого риска развития осложнений по шкале GRACE 2.0 в течение госпитализации и 12 мес. при использовании различных маркеров значимо не различались (p<0,05). При сравнении показателей AUC изучавшихся кардиомаркеров в отношении развития всех конечных точек с помощью шкалы GRACE 2.0 достоверных различий также не выявлено (p<0,05).Заключение. Включение в шкалу GRACE 2.0 сБСЖК по эффективности прогнозирования течения ОКС не уступает традиционным маркерам повреждения миокарда и может применяться, наряду с ними, для стратификации риска у больных ОКС

НЕОРГАНИЧЕСКИЕ ФОТОРЕЗИСТЫ НА ОСНОВЕ СМЕШАННЫХ ОКСИДОВ МОЛИБДЕНА И ВАНАДИЯ

The possibility of application of thin films of molybdenum-vanadium oxide as the photoresist material was demonstrated. The photosensitivity of such a system was due to the photo-induced polycondensation of polymolybdic acid oligomers in xerogel V2O5 : MoO3 films.Продемонстрирована возможность использования тонких пленок смешанного молибден-ванадиевого оксида в качестве неорганического фоторезистного материала для получения высокоустойчивых рисунков-масок. В основе фоточувствительности систем такого рода лежит фотоиндуцированная поликонденсация олигомеров смешанных полиоксокислот в пленках ксерогеля V2O5 : MoO3

СОЛЬВОТЕРМИЧЕСКИЙ СИНТЕЗ МОЛИБДЕН-ВАНАДИЕВЫХ КАТАЛИЗАТОРОВ НА НОСИТЕЛЯХ ИЗ ДИОКСИДА КРЕМНИЯ

The possibility of solvothermal deposition of mixed oxide of molybdenum-vanadium on an inert silica carrier (mesoporous grains, nanoparticles) via the polycondensation of mixed molybdenum- vanadium acid under controlled conditions has been demonstrated. It is shown that the obtained catalysts representing the solid V2O5 : MoO3 solution exhisit the high activity in the reaction of thiophene oxidation at 250 °С and can be used for desulphation of hydrocarbons.Продемонстрирована возможность сольвотермического осаждения смешанного оксида молибдена-ванадия на инертный носитель из диоксида кремния в виде мезопористых гранул и наночастиц за счет поликонденсации смешанной молибден-ванадиевой кислоты в контролируемых условиях. Показано, что полученные нанесенные катализаторы, представляющие собой твердый раствор V2O5 : MoO3, характеризуются высокой активностью в реакции окисления тиофена при температуре 250 °С, что позволяет использовать их в качестве основы перспективных систем десульфирования углеводородного сырья

INVESTIGATION OF THE SPECTRAL CHARACTERISTICS OF POLYVINYLPYRROLIDONE-IODINE IN THE FIELD OF LOW-FREQUENCY VIBROACOUSTIC OSCILLATIONS

The change in the optical density spectrum of povidone-iodine in the field of low-frequency oscillations was studied. A conclusion about the dissociation of the complex under the action of infrasound is made. Partially confirmed data on the structure of the complex