122 research outputs found

    A reversible protonic ceramic cell with symmetrically designed Pr2NiO4+δ-based electrodes: Fabrication and electrochemical features

    Get PDF
    Reversible protonic ceramic cells (rPCCs) combine two different operation regimes, fuel cell and electrolysis cell modes, which allow reversible chemical-to-electrical energy conversion at reduced temperatures with high efficiency and performance. Here we present novel technological and materials science approaches, enabling a rPCC with symmetrical functional electrodes to be prepared using a single sintering step. The response of the cell fabricated on the basis of P-N- BCZD|BCZD|PBN-BCZD (where BCZD = BaCe0.5Zr0.3Dy0.2O3-δ, PBN = Pr1.9Ba0.1NiO4+δ, P = Pr2O3, N = Ni) is studied at different temperatures and water vapor partial pressures (pH2O) by means of volt-ampere measurements, electrochemical impedance spectroscopy and distribution of relaxation times analyses. The obtained results demonstrate that symmetrical electrodes exhibit classical mixed-ionic/electronic conducting behavior with no hydration capability at 750 °C; therefore, increasing the pH2O values in both reducing and oxidizing atmospheres leads to some deterioration of their electrochemical activity. At the same time, the electrolytic properties of the BCZD membrane are improved, positively affecting the rPCC's efficiency. The electrolysis cell mode of the rPCC is found to be more appropriate than the fuel cell mode under highly humidified atmospheres, since its improved performance is determined by the ohmic resistance, which decreases with pH2O increasing. © 2018 by the authors.Российский Фонд Фундаментальных Исследований (РФФИ): 18-38-20063Funding: The majority of this work was carried out under the budgetary plans of Institute of High Temperature Electrochemistry. The design of new electrode materials and their characterization was also funded by the Russian Foundation for Basic Research, grant number 18-38-20063. Dr. Dmitry Medvedev is also grateful to the Council of the President of the Russian Federation (scholarship СП-161.2018.1) for supporting the studies devoted to search of new Co-free electrode materials

    Densification, morphological and transport properties of functional La1–xBaxYbO3– δ ceramic materials

    Full text link
    The effective operation of protonic ceramic electrochemical cells requires the design of electrolytes having not only high ionic conductivity, but also excellent stability with respect to carbonisation. In the present work, the La-based oxides (La1–xBaxYbO3–δ, 0.03 ≤ x ≤ 0.10) are proposed as a possible alternative to the convenient Ba(Ce,Zr)O3-based electrolytes due to their high chemical stability. It was discovered that Ba-doping results in a deterioration of sintering behaviour; as a result, the relative density decreases and open porosity appears (for x = 0.10). A thorough analysis of transport properties by means of AC and DC measurement techniques enables a selection of the La0.97Ba0.03YbO3–δ sample, which demonstrates the highest conductivity compared with those samples where x = 0.5 and 0.10. Due to its excellent densification behaviour, stability and ionic conductivity, La0.97Ba0.03YbO3–δ can be considered as a promising proton-conducting electrolyte in the La-based family. © 2019 Elsevier Lt

    Prognostic value of leukocyte indices in acute severe pancreatitis

    Get PDF
    The article analyzed the results of laboratory blood tests obtained in patients on the day of entry into the body and calculated for various leukocyte indices in patients with acute severe pancreatitis. The study based on the case reports of the MAI “City Clinical Hospital” No. 40 of Yekaterinburg in the period 2015-2020. The study aim is to identify the informative value of leukocyte indicators in relation to predicting the severity of acute pancreatitis and mortality. Some leukocyte indices have sufficient information in predicting the severity, course of acute pancreatitis and mortality, taking into account the incidence.В статье были проанализированы результаты лабораторных исследований крови, полученных у пациентов в день поступления в приемный покой и рассчитаны различные лейкоцитарные индексы у пациентов с острым тяжелым панкреатитом. Исследование проведено по материалам историй болезни МАУ «Городская клиническая больница» №40 г. Екатеринбурга в период 2015-2020 гг. Проведенное исследование было направлено на выявление информативности лейкоцитарных индексов в отношении прогнозирования тяжести течения острого панкреатита и летальности. Некоторые лейкоцитарные индексы обладают достаточной информативностью в прогнозировании тяжести течения острого панкреатита и летальности, связанной с данным заболеванием

    TCRep 3D: An Automated In Silico Approach to Study the Structural Properties of TCR Repertoires

    Get PDF
    TCRep 3D is an automated systematic approach for TCR-peptide-MHC class I structure prediction, based on homology and ab initio modeling. It has been considerably generalized from former studies to be applicable to large repertoires of TCR. First, the location of the complementary determining regions of the target sequences are automatically identified by a sequence alignment strategy against a database of TCR Vα and Vβ chains. A structure-based alignment ensures automated identification of CDR3 loops. The CDR are then modeled in the environment of the complex, in an ab initio approach based on a simulated annealing protocol. During this step, dihedral restraints are applied to drive the CDR1 and CDR2 loops towards their canonical conformations, described by Al-Lazikani et. al. We developed a new automated algorithm that determines additional restraints to iteratively converge towards TCR conformations making frequent hydrogen bonds with the pMHC. We demonstrated that our approach outperforms popular scoring methods (Anolea, Dope and Modeller) in predicting relevant CDR conformations. Finally, this modeling approach has been successfully applied to experimentally determined sequences of TCR that recognize the NY-ESO-1 cancer testis antigen. This analysis revealed a mechanism of selection of TCR through the presence of a single conserved amino acid in all CDR3β sequences. The important structural modifications predicted in silico and the associated dramatic loss of experimental binding affinity upon mutation of this amino acid show the good correspondence between the predicted structures and their biological activities. To our knowledge, this is the first systematic approach that was developed for large TCR repertoire structural modeling

    Rotavirus NSP1 Inhibits NFκB Activation by Inducing Proteasome-Dependent Degradation of β-TrCP: A Novel Mechanism of IFN Antagonism

    Get PDF
    Mechanisms by which viruses counter innate host defense responses generally involve inhibition of one or more components of the interferon (IFN) system. Multiple steps in the induction and amplification of IFN signaling are targeted for inhibition by viral proteins, and many of the IFN antagonists have direct or indirect effects on activation of latent cytoplasmic transcription factors. Rotavirus nonstructural protein NSP1 blocks transcription of type I IFNα/β by inducing proteasome-dependent degradation of IFN-regulatory factors 3 (IRF3), IRF5, and IRF7. In this study, we show that rotavirus NSP1 also inhibits activation of NFκB and does so by a novel mechanism. Proteasome-mediated degradation of inhibitor of κB (IκBα) is required for NFκB activation. Phosphorylated IκBα is a substrate for polyubiquitination by a multisubunit E3 ubiquitin ligase complex, Skp1/Cul1/F-box, in which the F-box substrate recognition protein is β-transducin repeat containing protein (β-TrCP). The data presented show that phosphorylated IκBα is stable in rotavirus-infected cells because infection induces proteasome-dependent degradation of β-TrCP. NSP1 expressed in isolation in transiently transfected cells is sufficient to induce this effect. Targeted degradation of an F-box protein of an E3 ligase complex with a prominent role in modulation of innate immune signaling and cell proliferation pathways is a unique mechanism of IFN antagonism and defines a second strategy of immune evasion used by rotaviruses

    Congruences of finite automata

    No full text
    corecore