Correlation between structural and transport properties of ca-doped la nickelates and their electrochemical performance

This work presents the results from a study of the structure and transport properties of Ca-doped La2NiO4+δ. La2−xCaxNiO4+δ (x = 0–0.4) materials that were synthesized via combustion of organic-nitrate precursors and characterized by X-ray diffraction (XRD), in situ XRD using synchrotron radiation, thermogravimetric analysis (TGA) and isotope exchange of oxygen with C18O2. The structure was defined as orthorhombic (Fmmm) for x = 0 and tetragonal (I4/mmm) for x = 0.1–0.4. Changes that occurred in the unit cell parameters and volume as the temperature changed during heating were shown to be caused by the excess oxygen loss. Typical for Ruddlesden–Popper phases, oxygen mobility and surface reactivity decreased as the Ca content was increased due to a reduction in the over-stoichiometric oxygen content with the exception of x = 0.1. This composition demonstrated its superior oxygen transport properties compared to La2NiO4+δ due to the enhanced oxygen mobility caused by structural features. Electrochemical data obtained showed relatively low polarization resistance for the electrodes with a low Ca content, which correlates well with oxygen transport properties. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The materials synthesis as well as electrochemical study were performed in a framework of the budget task of the IHTE UB RAS with using the equipment of the shared access center “Composition of compounds”. The TGA and isotope exchange studies were supported by the Ministry of Science and Higher Education of the Russian Federation within the governmental order for Boreskov Institute of Catalysis (projects АААА‐А21‐121011390007‐7, АААА‐А21‐ 121011390009‐1). The SXRD experiments were performed at the shared research center SSTRC on the basis of the Novosibirsk VEPP‐3 complex at BINP SB RAS, using equipment supported by pro‐ ject RFMEFI62119X0022

Análise do termo de primeira ordem das séries de Molodenskii para o problema de valor de contorno da geodésia

Neste trabalho, avaliou-se o termo de primeira ordem das séries de Molodenskii usando as seguintes abordagens: a solução dada pela série de Molodenskii; a solução pelo gradiente vertical; e a solução pela correção de terreno como aproximação do termo <img border=0 width=32 height=32 src="../../../../img/revistas/bcg/v16n4/a05simb03.jpg">. As duas últimas soluções foram obtidas por Moritz. As duas primeiras soluções mostraram-se coerentes entre si nas condições aqui analisadas. A comparação foi feita em termos de anomalia de altitude de primeira ordem <img border=0 width=32 height=32 src="../../../../img/revistas/bcg/v16n4/a05simb04.jpg">. Em termos do quase geoide final, o uso da correção de terreno em vez do termo <img border=0 width=32 height=32 src="../../../../img/revistas/bcg/v16n4/a05simb03.jpg">mostrou-se eficiente em termos da avaliação realizada com dados independentes; neste caso, 42 referências de nível posicionadas por GPS. A metodologia, os resultados, as discussões, conclusões e recomendações práticas são apresentadas

Language. Antinomy. Dialogue

What is the nature of language? Does it exist as an ideal object, before and above verbal communication hic et nunc? Or, has it got its existence only within concrete speech acts, concrete communication? This century has witnessed ceaseless battles with innumerable supporters of either side of the argument. And no side has so far managed to completely defeat its rivals. Rather, both sides succeeded in pointing out the serious drawbacks and incompleteness in each other’s theoretical programmes

In situ X-ray diffraction studies of Pr2 − xNiO4 + δ crystal structure relaxation caused by oxygen loss

Fine powders of Pr2 − xNiO4 + δ (PNO) oxides (x=0÷0.3) synthesized by Pechini routewere uniaxially pressedinto pellets and sintered at 1300 °C under air. Chemical diffusion coefficients (Dchem.) and surface exchange constants(kchem.) were estimated by analysis of the weight and conductivity relaxations after step-wise change ofpO2. In situ XRD studies were carried out in VEPP-3 facilities of the Siberian Center of Synchrotron Radiationusing unique high-temperature camera and procedures.Analysis of dynamics of the cell volume expansion caused by oxygen loss with due regard for penetration depthof X-rays into the pellet allowed to estimate Dchem and kchem found to be close to those obtained by traditionalmethods. Isolated Pr vacancies appear to be the most important for fast oxygen diffusion and high surface reactivityproviding the highest values of kchem and Dchem for Pr1.9NiO4 + δ composition

Respir. Res.

Background Tumour necrosis factor (TNF) is crucial for the control of mycobacterial infection as TNF deficient (KO) die rapidly of uncontrolled infection with necrotic pneumonia. Here we investigated the role of membrane TNF for host resistance in knock-in mice with a non-cleavable and regulated allele (mem-TNF). Methods C57BL/6, TNF KO and mem-TNF mice were infected with M. tuberculosis H37Rv (Mtb at 100 CFU by intranasal administration) and the survival, bacterial load, lung pathology and immunological parameters were investigated. Bone marrow and lymphocytes transfers were used to test the role of membrane TNF to confer resistance to TNF KO mice. Results While TNF-KO mice succumbed to infection within 4–5 weeks, mem-TNF mice recruited normally T cells and macrophages, developed mature granuloma in the lung and controlled acute Mtb infection. However, during the chronic phase of infection mem-TNF mice succumbed to disseminated infection with necrotic pneumonia at about 150 days. Reconstitution of irradiated TNF-KO mice with mem-TNF derived bone marrow cells, but not with lymphocytes, conferred host resistance to Mtb infection in TNF-KO mice. Conclusion Membrane expressed TNF is sufficient to allow cell-cell signalling and control of acute Mtb infection. Bone marrow cells, but not lymphocytes from mem-TNF mice confer resistance to infection in TNF-KO mice. Long-term infection control with chronic inflammation likely disrupting TNF mediated cell-cell signalling, additionally requires soluble TNF

Partial redundancy of the pattern recognition receptors, scavenger receptors, and C-type lectins for the long-term control of Mycobacterium tuberculosis infection.

Mycobacterium tuberculosis is recognized by multiple pattern recognition receptors involved in innate immune defense, but their direct role in tuberculosis pathogenesis remains unknown. Beyond TLRs, scavenger receptors (SRs) and C-type lectins may play a crucial role in the sensing and signaling of pathogen motifs, as well as contribute to M. tuberculosis immune evasion. In this study, we addressed the relative role and potential redundancy of these receptors in the host response and resistance to M. tuberculosis infection using mice deficient for representative SR, C-type lectin receptor, or seven transmembrane receptor families. We show that a single deficiency in the class A SR, macrophage receptor with collagenous structure, CD36, mannose receptor, specific ICAM-3 grabbing nonintegrin-related, or F4/80 did not impair the host resistance to acute or chronic M. tuberculosis infection in terms of survival, control of bacterial clearance, lung inflammation, granuloma formation, and cytokine and chemokine expression. Double deficiency for the SRs class A SR types I and II plus CD36 or for the C-type lectins mannose receptor plus specific ICAM-3 grabbing nonintegrin-related had a limited effect on macrophage uptake of mycobacteria and TNF response and on the long-term control of M. tuberculosis infection. By contrast, mice deficient in the TNF, IL-1, or IFN-gamma pathway were unable to control acute M. tuberculosis infection. In conclusion, we document a functional redundancy in the pattern recognition receptors, which might cooperate in a coordinated response to sustain the full immune control of M. tuberculosis infection, in sharp contrast with the nonredundant, essential role of the TNF, IL-1, or IFN-gamma pathway for host resistance to M. tuberculosis

Proteins of the Rpf Family: Immune Cell Reactivity and Vaccination Efficacy against Tuberculosis in Mice

It was shown recently that Mycobacterium tuberculosis expresses five proteins that are homologous to Rpf (resuscitation promoting factor), which is secreted by growing cells of Micrococcus luteus. Rpf is required to resuscitate the growth of dormant Micrococcus luteus organisms, and its homologues may be involved in mycobacterial reactivation. Mycobacterial Rpf-like products are secreted proteins, which makes them candidates for recognition by the host immune system and anti-Rpf immune responses potentially protective against reactivated tuberculosis. Here we report that the Rpf protein itself and four out of five of its mycobacterial homologues, which were administered as subunit vaccines to C57BL/6 mice, are highly immunogenic. Rpf-like proteins elicit immunoglobulin G1 (IgG1) and IgG2a responses and T-cell proliferation and stimulate production of gamma interferon, interleukin-10 (IL-10), and IL-12 but not IL-4 or IL-5. Both humoral and T-cell responses against these antigens show a high degree of cross-reactivity. Vaccination of mice with Rpf-like proteins results in a significant level of protection against a subsequent high-dose challenge with virulent M. tuberculosis H37Rv, both in terms of survival times and mycobacterial multiplication in lungs and spleens

Increased expression of Mycobacterium tuberculosis 19 kDa lipoprotein obliterates the protective efficacy of BCG by polarizing host immune responses to the Th2 subtype

Mycobacterium tuberculosis can not only neutralize immune effector functions, but also has the ability to modulate host-signalling cascades involved in the development of these responses. The 19 kDa antigen (Rv3763), a lipoprotein of M. tuberculosis, elicits high levels of interleukin (IL)-12 from macrophages in addition to its powerful immunomodulatory properties, leading to suppression of antigen-presentation signalling cascades. The present study was aimed at analysing the effect of overexpression of this antigen on the immunostimulatory properties of M. bovis Bacille Calmette–Gue´rin (BCG). We have constructed a recombinant BCG strain (rBCG19N) producing higher levels of the 19 kDa antigen in both the cytoplasmic (approximately eightfold) and extracellular (approximately fivefold) fractions as compared to the wildtype BCG. Immunization of mice with rBCG19N elicited high levels of interferon-gamma (IFN-g) and relatively low levels of IL-10 against the purified 19 kDa antigen. However, in response to total BCG sonicate, mice immunized with rBCG19N produced significantly high levels of IL-10 with relatively very low levels of IFN-g. This polarization of the host immune responses towards T-helper 2 subtype resulted in complete abrogation of the protective efficacy of BCG, when rBCG19N was used as a live vaccine against M. tuberculosis challenge in guinea pigs