Stuffed Rare Earth Pyrochlore Solid Solutions

Synthesis and crystal structures are described for the compounds Ln2(Ti2-xLnx)O7-x/2, where Ln = Tb, Dy, Ho, Er, Tm, Yb, Lu, and x ranges from 0 to 0.67. Rietveld refinements on X-ray powder diffraction data indicate that in Tb and Dy titanate pyrochlores, extra Ln3+ cations mix mainly on the Ti4+ site with little disorder on the original Ln3+ site. For the smaller rare earths (Ho-Lu), stuffing additional lanthanide ions results in a pyrochlore to defect fluorite transition, where the Ln3+ and Ti4+ ions become completely randomized at the maximum (x=0.67). In all of these Ln-Ti-O pyrochlores, the addition of magnetic Ln3+ in place of nonmagnetic Ti4+ adds edge sharing tetrahedral spin interactions to a normally corner sharing tetrahedral network of spins. The increase in spin connectivity in this family of solid solutions represents a new avenue for investigating geometrical magnetic frustration in the rare earth titanate pyrochlores.Comment: 25 pages, 7 figures, submitted to J. Solid State Che

Anionic Micelle-Forming Triblock Copolymers as Nanocontainers for Doxorubicin

The anionic derivative of asymmetric triblock copolymer containing biocompatible chemically complementary polyacrylamide and poly(ethylene oxide) (PAAm-b-PEO-b-PAAm) was obtained. The micellization of the initial (TBC) and modified (TBC-COOH) copolymer samples in aqueous solution were investigated. Practically the same values of the critical micellization concentration and the Gibbs free micellization energy for both TBCs were found. The anticancer effects of the doxorubicin (DOX)-loaded micelles of the initial and modified triblock copolymers were studied on the tumor cells of human T-leukemia of Jurkat line, transformed leukemia of L929 line and mouse lymphatic leukemia of L1210 line. The fact of high efficacy of DOX/TBC and DOX/TBC-COOH compositions in compare with pure DOX was determined and discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3497

Study of oxygen-ion conductivity and luminescence in the ZrO2-Nd2O3 system : impact of local heterogeneity

Stabilized fluorites and pyrochlores with different types of substitution in the (Nd2O3 ? ZrO2 system (NdZrO)) have been studied by Raman spectroscopy, X-ray diffraction, and impedance spectroscopy methods. Ionic and proton conductivity maps for 9 compositions in the NdZrO system are presented. Oxygen partial pressure measurements show a typical ionic conductor behavior, with a significantly increase of conductivity for (Nd2?xZrx)Zr2O7+x/2 (x = 1.27) fluorite and (Nd2?xZrx)Zr2O7+x/2 (x = 0.4, 0.2) pyrochlores. For the same compositions the strong luminescence was observed. Strong luminescence and high oxygenion conductivity of these solid solutions can be associated with the presence of phases with the different degree of structural disorder (tetragonal phase, fluorite) in local nanodomains in fluorite or pyrochlore matrix in the ZrO2 ? Nd2Zr2O7 region. Really, Raman spectra of (Nd2?xZrx)Zr2O7+x/2 (x = 0.5 ? 0.2) solid solutions demonstrated the fluorite + pyrochlore structural type in the short-range order. Fluorite nanodomains in pyrochlore matrix (ZrO2 ? Nd2Zr2O7 region) resulting from an order?disorder transition can only be detected at a radiation wavelength comparable to the fluorite nanodomain size. Thus, using Raman spectroscopy the broad isomorphism range in the ZrO2 ? Nd2Zr2O7 system has been shown to be nonuniform.371C-9F16-EBDE | Eduarda GomesN/

Effect of Pr3+/Pr4+ ratio on the oxygen ion transport and thermomechanical properties of the pyrochlore and fluorite phases in the ZrO2-Pr2O3 system

This paper examines the effect of the Pr3+/Pr4+ ratio on the mechanism of ionic and electronic transport in the (Pr2?xZrx)Zr2O7+x/2 (x = 0.15), Pr2Zr2O7, and Pr2(Zr2?xPrx)O7?x/2 (x = 0.1) pyrochlore phases and Pr3ZrOx with the fluorite structure and on the behavior of their thermal expansion coefficient (TEC). The solid solutions were prepared through coprecipitation followed by firing of the green compacts in air at a high temperature of 1550 ?C for 4 h. The Pr3+/Pr4+ ratio was shown to decrease in going from the (Pr2?xZrx)Zr2O7+x/2 (x = 0.15), Pr2Zr2O7, and Pr2(Zr2?xPrx)O7?x/2 (x = 0.1) pyrochlores to the Pr3ZrOx fluorite, leading to changes in the conductivity type from mixed (ionic?electronic) to electronic and in the color of the materials from beige to black and to an anomalous deviation of the TEC from linearity in fluorite Pr3ZrOx, i.e. at the highest Pr4+ content. According to impedance spectroscopy results, (Pr2?xZrx)Zr2O7+x/2 with x = 0.15 has purely oxide-ion conductivity (3 ? 10?3 S/cm at 1000 ?C) in a wide range of oxygen partial pressures: from 10?10 to 102 Pa. With increasing Pr content, p-type electronic conductivity becomes significant, reaching a maximum in fluorite Pr3ZrOx: ?0.5 S/cm at 1000 ?C. According to XPS data, all pyrochlore samples (Pr2?xZrx)Zr2O7+x/2 (x = 0.15), Pr2Zr2O7 and Pr2(Zr2?xPrx)O7?x/2 (x = 0.1) contain only Pr3+ at room temperature, whereas Pr3ZrOx contains both Pr3+ and Pr4+. The considerable deviation of the TEC of Pr3ZrOx from linearity above 500 ?C is due to partial reduction of Pr4+. The reduction process Pr4+ + e? ? Pr3+ followed by oxygen release in the range 500?1100 ?C has been identified in Pr3ZrOx by thermal analysis and mass spectrometry in a He atmosphere.371C-9F16-EBDE | Eduarda GomesN/

Protocol to study the inheritance and propagation of non-genetically encoded states using barcode decay lineage tracing

Here, we present a protocol to perform barcode decay lineage tracing followed by single-cell transcriptome analysis (BdLT-Seq). We describe steps for BdLT-Seq experimental design, building barcoded episome reporters, performing episome transfection, and barcode retrieval. We then describe procedures for sequencing library construction while providing options for sample multiplexing and data analysis. This BdLT-Seq technique enables the assessment of clonal evolution in a directional manner while preserving isogeneity, thus allowing the comparison of non-genetic molecular features between isogenic cell lineages. For complete details on the use and execution of this protocol, please refer to Shlyakhtina et al. (2023). . [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.

Assessment strategies in ESP distance Learning

Miniailova, A. V. Assessment strategies in ESP distance Learning = Основні методи оцінювання в процесі дистанційного викладання англійської мови для спеціальних цілей / A. V. Miniailova, O. S. Shlyakhtina // Гуманіт. вісн. НУК. – Миколаїв : НУК, 2021. – Вип. 13. – С. 33–38.У статті розкрито сутність і задачі оцінювання як важливої складової навчального процесу. Окреслено особливості дистанційної форми навчання у закладах вищої освіти в умовах карантину, запровадженого урядом України через пандемію. Проаналізовано основні методи оцінювання в процесі дистанційного викладання англійської мови для спеціальних цілей.The article reveals the essence and objectives of assessment as an important component of the educational process. The peculiarities of distance learning in higher education institutions in the conditions of quarantine introduced by the Government of Ukraine due to a pandemic have been outlined. The main methods of assessment in the process of ESP distance learning have been analyzed

Plasminogen activator urokinase expression reveals TRAIL responsiveness and supports fractional survival of cancer cells

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