Predictive model to identify multiple failure to biological therapy in patients with rheumatoid arthritis

Despite advances in the treatment of rheumatoid arthritis (RA) and the wide range of therapies available, there is a percentage of patients whose treatment presents a challenge for clinicians due to lack of response to multiple biologic and target-specific disease-modifying antirheumatic drugs (b/tsDMARDs).To develop and validate an algorithm to predict multiple failure to biological therapy in patients with RA.Observational retrospective study involving subjects from a cohort of patients with RA receiving b/tsDMARDs.Based on the number of prior failures to b/tsDMARDs, patients were classified as either multi-refractory (MR) or non-refractory (NR). Patient characteristics were considered in the statistical analysis to design the predictive model, selecting those variables with a predictive capability. A decision algorithm known as 'classification and regression tree' (CART) was developed to create a prediction model of multi-drug resistance. Performance of the prediction algorithm was evaluated in an external independent cohort using area under the curve (AUC).A total of 136 patients were included: 51 MR and 85 NR. The CART model was able to predict multiple failures to b/tsDMARDs using disease activity score-28 (DAS-28) values at 6 months after the start time of the initial b/tsDMARD, as well as DAS-28 improvement in the first 6 months and baseline DAS-28. The CART model showed a capability to correctly classify 94.1% NR and 87.5% MR patients with a sensitivity = 0.88, a specificity = 0.94, and an AUC = 0.89 (95% CI: 0.74-1.00). In the external validation cohort, 35 MR and 47 NR patients were included. The AUC value for the CART model in this cohort was 0.82 (95% CI: 0.73-0.9).Our model correctly classified NR and MR patients based on simple measurements available in routine clinical practice, which provides the possibility to characterize and individualize patient treatments during early stages.© The Author(s), 2022

Microwave-induced fast crystallization of amorphous hierarchical anatase microspheres

The fabrication of hierarchical anatase microspheres with potential photocatalytic properties eventually comprises a consolidation step in which a high degree of crystalline order is typically achieved through conventional electric heating treatments. This however entails a substantial reduction in the specific surface area and porosity of the powders, with the consequent deterioration in their photocatalytic response. Here, we have tested the employ of microwave heating as an alternative energy-saving sintering method to promote fast crystallization. The results obtained suggest that under the microwave radiation, the TiO(2) hierarchical structures can effectively crystallize in a drastically reduced heating time, allowing the specific surface area and the porosity to be kept in the high values required for an improved photocatalytic performance

Phase evolution of Zn1−xMnxO system synthesized via oxalate precursors

Polycrystalline samples with nominal composition Zn1−xMnxO have been prepared by a co-precipitation technique in which kinetics of high temperature reactions are favoured by the use of highly reactive particles. Structural and compositional analysis reveal that following the decomposition of the oxalate precursor a secondary ZnMnO3 phase is formed already at 400 ◦C. By means of XRD and HRTEM, a defect spinel-type structure is presumed for this Zn–Mn–O compound. A diluted magnetic semiconductor in which Mn atoms are homogeneously substituting Zn atoms in the semiconductor matrix is not obtained in the whole temperature range by this synthesis method. The microstructural situation is then far from that theoretically predicted for spintronic systems.Peer reviewe

Mn(3−x)ZnxO4 spinel phases in the Zn–Mn–O system

8 pages, 9 figures, 3 tables.-- Printed version published Sep 2008.The thermal evolution of the Zn–Mn–O system in air was studied by X-ray diffraction, transmission electron microscopy–energy dispersive spectroscopy and electron energy loss spectroscopy. The obtained results suggest that this evolution involves the formation of different Mn(3−x)ZnxO4 spinel-type phases. With increasing temperature these spinels experience phase transformations which are found to be induced by the Mn(IV) to Mn(III) reduction process. This last cation is an active Jahn–Teller ion which leads to an appreciable distortion of the Mn(3−x)ZnxO4 spinel structure, from a cubic symmetry at low temperatures to highly distorted tetragonal symmetries at high temperatures.The authors would like to express their gratitude to the Ministry of Higher Education, Science and Technology of Slovenia for its financial support. M.P. also acknowledges the Secretaría de Estado de Universidades e Investigación del Ministerio de Educación y Ciencia (Spain) for the financial support. This work has been conducted within the CICYT MAT 2007-65857 and CICYT MAT 2007-66845-C02-01 projects.Peer reviewe

Control microestructural en varistores cerámicos basados en el sistema ZnO-Bi₂O₃-Sb₂O₃ dopados con TiO₂

Typically Titanium oxide is added to the formulation of Bi₂O₃-doped ZnO based varistors to enhance the growth of ZnO grains, thus allowing their application in low voltage devices. However its incorporation to formulation based on the ZnOBi₂O₃-Sb₂O₃ (ZBS system), characteristic of high voltage applications has not been analyzed jet. In this contribution it has been verified that far from promoting the ZnO grain growth, the incorporation of TiO₂ to varistor formulations based on this ZBS ternary system leads to a better control of the varistor microstructure, which in turns causes an appreciable improvement of its electrical response.<br><br>Típicamente el Óxido de Titanio se incorpora a la formulación de varistores basados en ZnO dopado con Bi₂O₃ para favorecer un crecimiento de los granos de ZnO, lo que determina su aplicación en dispositivos de bajo voltaje. Sin embargo su incorporación en formulaciones basadas en el ternario ZnO-Bi₂O₃-Sb₂O₃ (sistema ZBS), características de aplicaciones de alto voltaje, es algo que apenas se ha analizado. En este trabajo se ha comprobado que lejos de favorecer el crecimiento de los granos de ZnO, la incorporación de TiO₂ a sistemas basados en dicho ternario ZBS lleva a un mayor control de la microestructura de estos electrocerámicos, y esto además se traduce en una apreciable mejoría de su respuesta eléctrica

Microwave-induced fast crystallization of amorphous hierarchical anatase microspheres

The fabrication of hierarchical anatase microspheres with potential photocatalytic properties eventually comprises a consolidation step in which a high degree of crystalline order is typically achieved through conventional electric heating treatments. This however entails a substantial reduction in the specific surface area and porosity of the powders, with the consequent deterioration in their photocatalytic response. Here, we have tested the employ of microwave heating as an alternative energy-saving sintering method to promote fast crystallization. The results obtained suggest that under the microwave radiation, the TiO2 hierarchical structures can effectively crystallize in a drastically reduced heating time, allowing the specific surface area and the porosity to be kept in the high values required for an improved photocatalytic performance.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through the projects IPT-120000-2010-033 (GESHTOS), IPT-2011-1113-310000 (NANOBAC), CICYTMAT 2010-16614, MAT2010-18432 and CSD2008-00023. Dr T. Jardiel also acknowledges the JAE-Doc contract of the Spanish National Research Council (CSIC) and the European Science Foundation (ESF). Dr M. Peiteado acknowledges the Ramon y Cajal Program of MINECO for the financial support

Parámetros de procesamiento para varistores basados en ZnO preparados por serigrafía

[EN] Thick film varistors based on the ZnO-Bi2O3-Sb2O3 system have been prepared by screen printing on dense alumina substrates. Different processing parameters like the paste viscosity, burn out and sintering cycles, green and sintered thickness, have been studied to improve the processing of ZnO-based thick film varistors. Starting powders were pre-treated in two different ways in order to control both the Bi-rich liquid phase formation and the excessive volatilization of Bi2O3 during sintering due to the high area/volume ratio of the thick films. Significant changes have been observed in the electrical properties related to the different firing schedule and selection of the starting powders.[ES] Se han preparado varistores basados en el sistema ZnO-Bi2O3-Sb2O3 en forma de lámina gruesa sobre sustratos de alúmina densa. Diferentes parámetros del procesamiento como la viscosidad de la pasta, los ciclos de calcinación y sinterización y el espesor en verde y sinterizado han sido estudiados para mejorar el procesamiento de los varistores basados en ZnO preparados en forma de lámina gruesa. Los polvos de partida fueron pretratados de dos formas diferentes con el objetivo de controlar la formación de la fase líquida rica en bismuto y la excesiva volatilización de Bi2O3 durante la sinterización debida a la alta relación área-volumen de las láminas gruesas. Se han observado cambios significativos en las propiedades eléctricas relacionadas con los diferentes ciclos de calcinado y con la selección de los polvos de partida.This work has been developed within Marie Curie Training Site Ceramos (HPMT-CT-2001-00372) program and CYCYTMAT2004-04843-C02 project.Peer reviewe