465 research outputs found

    Modulating redox properties of solid-state ion-conducting materials using microwave irradiation

    Get PDF
    The industrial adoption of low-carbon technologies and renewable electricity requires novel tools for electrifying unitary steps and efficient energy storage, such as the catalytic synthesis of valuable chemical carriers. The recently-discovered use of microwaves as an effective reducing agent of solid materials provides a novel framework to improve this chemical-conversion route, thanks to promoting oxygen-vacancy formation and O-surface exchange at low temperatures. However, many efforts are still required to boost the redox properties and process efficiency. Here, we scrutinise the dynamics and the physicochemical dependencies governing microwave-induced redox transformations on solid-state ion-conducting materials. The reduction is triggered upon a material-dependent induction temperature, leading to a characteristically abrupt rise in electric conductivity. This work reveals that the released O yield strongly depends on the material's composition and can be tuned by controlling the gas-environment composition and the intensity of the microwave power. The reduction effect prevails at the grain surface level and, thus, amplifies for fine-grained materials, and this is ascribed to limitations in oxygen-vacancy diffusion across the grain compared to a microwave-enhanced surface evacuation. The precise cyclability and stability of the redox process will enable multiple applications like gas depuration, energy storage, or hydrogen generation in several industrial applications.This study forms part of the MFA programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana. Financial support by the Spanish Ministry of Science and Innovation (PID2022-139663OB-100 and CEX2021-001230-S grants funded by MCIN/AEI/10.13039/501100011033, and “Ramon y Cajal” Fellowship RYC2021-033889-I), and the Universitat Politècnica de València (UPV) are gratefully acknowledged. Also, we acknowledge the support of the Servicio de Microscopía Electrónica of the UPV

    First month prednisone dose predicts prednisone burden during the following 11 months: An observational study from the RELES cohort

    Get PDF
    Aim: To study the influence of prednisone dose during the first month after systemic lupus erythematosus (SLE) diagnosis (prednisone-1) on glucocorticoid burden during the subsequent 11 months (prednisone-2–12). Methods: 223 patients from the Registro Español de Lupus Eritematoso Sistémico inception cohort were studied. The cumulative dose of prednisone-1 and prednisone-2–12 were calculated and recoded into a four-level categorical variable: no prednisone, low dose (up to 7.5 mg/day), medium dose (up to 30 mg/day) and high dose (over 30 mg/day). The association between the cumulative prednisone-1 and prednisone-2–12 doses was tested. We analysed whether the four-level prednisone-1 categorical variable was an independent predictor of an average dose >7.5 mg/day of prednisone-2–12. Adjusting variables included age, immunosuppressives, antimalarials, methyl-prednisolone pulses, lupus nephritis and baseline SLE Disease Activity Index (SLEDAI). Results: Within the first month, 113 patients (51%) did not receive any prednisone, 24 patients (11%) received average low doses, 46 patients (21%) received medium doses and 40 patients (18%) received high doses. There was a strong association between prednisone-1 and prednisone-2–12 dose categories (p7.5 mg/day, while patients receiving low-dose prednisone-1 were not (adjusted OR 1.4, 95% CI 0. 0.38 to 5.2). If the analysis was restricted to the 158 patients with a baseline SLEDAI of =6, the model did not change. Conclusion: The dose of prednisone during the first month after the diagnosis of SLE is an independent predictor of prednisone burden during the following 11 months

    Climate Effects and Feedback Structure Determining Weed Population Dynamics in a Long-Term Experiment

    Get PDF
    Pest control is one of the areas in which population dynamic theory has been successfully applied to solve practical problems. However, the links between population dynamic theory and model construction have been less emphasized in the management and control of weed populations. Most management models of weed population dynamics have emphasized the role of the endogenous process, but the role of exogenous variables such as climate have been ignored in the study of weed populations and their management. Here, we use long-term data (22 years) on two annual weed species from a locality in Central Spain to determine the importance of endogenous and exogenous processes (local and large-scale climate factors). Our modeling study determined two different feedback structures and climate effects in the two weed species analyzed. While Descurainia sophia exhibited a second-order feedback and low climate influence, Veronica hederifolia was characterized by a first-order feedback structure and important effects from temperature and rainfall. Our results strongly suggest the importance of theoretical population dynamics in understanding plant population systems. Moreover, the use of this approach, discerning between the effect of exogenous and endogenous factors, can be fundamental to applying weed management practices in agricultural systems and to controlling invasive weedy species. This is a radical change from most approaches currently used to guide weed and invasive weedy species managements

    Lead Optimization of 3,5-Disubstituted-7-Azaindoles for the Treatment of Human African Trypanosomiasis

    Get PDF
    Neglected tropical diseases such as human African trypanosomiasis (HAT) are prevalent primarily in tropical climates and among populations living in poverty. Historically, the lack of economic incentive to develop new treatments for these diseases has meant that existing therapeutics have serious shortcomings in terms of safety, efficacy, and administration, and better therapeutics are needed. We now report a series of 3,5-disubstituted-7-azaindoles identified as growth inhibitors of Trypanosoma brucei, the parasite that causes HAT, through a high-throughput screen. We describe the hit-to-lead optimization of this series and the development and preclinical investigation of 29d, a potent antitrypanosomal compound with promising pharmacokinetic (PK) parameters. This compound was ultimately not progressed beyond in vivo PK studies due to its inability to penetrate the blood-brain barrier (BBB), critical for stage 2 HAT treatments

    The Vista Variables in the Via Lactea (VVV) ESO Public Survey: Current Status and First Results

    Get PDF
    25 pages, 18 figures. To appear in the Carnegie Observatories Astrophysics Series, Volume 525 pages, 18 figures. To appear in the Carnegie Observatories Astrophysics Series, Volume 5Vista Variables in the Via Lactea (VVV) is an ESO Public Survey that is performing a variability survey of the Galactic bulge and part of the inner disk using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA). The survey covers 520 deg^2 of sky area in the ZYJHK_S filters, for a total observing time of 1929 hours, including ~ 10^9 point sources and an estimated ~ 10^6 variable stars. Here we describe the current status of the VVV Survey, in addition to a variety of new results based on VVV data, including light curves for variable stars, newly discovered globular clusters, open clusters, and associations. A set of reddening-free indices based on the ZYJHK_S system is also introduced. Finally, we provide an overview of the VVV Templates Project, whose main goal is to derive well-defined light curve templates in the near-IR, for the automated classification of VVV light curves

    Neuron to Astrocyte Communication via Cannabinoid Receptors Is Necessary for Sustained Epileptiform Activity in Rat Hippocampus

    Get PDF
    Astrocytes are integral functional components of synapses, regulating transmission and plasticity. They have also been implicated in the pathogenesis of epilepsy, although their precise roles have not been comprehensively characterized. Astrocytes integrate activity from neighboring synapses by responding to neuronally released neurotransmitters such as glutamate and ATP. Strong activation of astrocytes mediated by these neurotransmitters can promote seizure-like activity by initiating a positive feedback loop that induces excessive neuronal discharge. Recent work has demonstrated that astrocytes express cannabinoid 1 (CB1) receptors, which are sensitive to endocannabinoids released by nearby pyramidal cells. In this study, we tested whether this mechanism also contributes to epileptiform activity. In a model of 4-aminopyridine induced epileptic-like activity in hippocampal slice cultures, we show that pharmacological blockade of astrocyte CB1 receptors did not modify the initiation, but significantly reduced the maintenance of epileptiform discharge. When communication in astrocytic networks was disrupted by chelating astrocytic calcium, this CB1 receptor-mediated modulation of epileptiform activity was no longer observed. Thus, endocannabinoid signaling from neurons to astrocytes represents an additional significant factor in the maintenance of epileptiform activity in the hippocampus

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

    Get PDF
    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    The network of photodetectors and diode lasers of the CMS Link alignment system

    Get PDF
    The central feature of the CMS Link alignment system is a network of Amorphous Silicon Position Detectors distributed throughout the muon spectrometer that are connected by multiple laser lines. The data collected during the years from 2008 to 2015 is presented confirming an outstanding performance of the photo sensors during more than seven years of operation. Details of the photo sensor readout of the laser signals are presented. The mechanical motions of the CMS detector are monitored using these photosensors and good agreement with distance sensors is obtained

    Un análisis exploratorio de la relación entre pobreza multidimensional y conflicto armado : el caso de Antioquia en Colombia

    Get PDF
    RESUMEN: Este artículo analiza la relación entre pobreza y conflicto armado en Antioquia, Colombia. El análisis de la pobreza está enmarcado en el enfoque de las capacidades de Sen, el cual conforma la base conceptual del índice de pobreza multidimensional (IPM) desarrollado por Alkire y Foster. El IPM es calculado con información derivada de la base de datos Sisbén, la cual se utiliza para seleccionar la población atendida por los programas de asistencia social del Gobierno colombiano. Este artículo consideró tres dimensiones de pobreza: estándares de vida, salud, y educación. El conflicto armado fue medido por medio de datos de conteo acerca de la ocurrencia de eventos de violencia registrados entre 1996 y 2010 en cada municipalidad de Antioquia. Luego, la relación entre la pobreza y el conflicto armado se analizó mediante métodos exploratorios y no paramétricos como las distribuciones kernel. Los resultados sugieren que el IPM es robusto con respecto a la elección del umbral de pobreza multidimensional. Los mapas de caja y bigotes sugieren que los pobres están localizados en las regiones periféricas de Antioquia. Las distribuciones kernel muestran que las áreas más afectadas por el conflicto, usualmente, tienen altos niveles de pobreza multidimensional.ABSTRACT: This paper analyses the relationship between poverty and armed conflict in Antioquia, Colombia. The poverty analysis it uses is framed according to Sen’s capability approach, which constitutes the conceptual basis for the Multidimensional Poverty Index (MPI) subsequently developed by Alkire and Foster. The MPI is measured employing data from the government database SISBEN, which is used by the Colombian authorities to identify beneficiaries of social assistance programmes. The paper considers three poverty dimensions: living standards, health, and education. Armed conflict is measured using count data on violent events recorded for every municipality in the Department of Antioquia between 1996 and 2010. The relationship between poverty and armed conflict is then analysed using exploratory and non-parametric methods such as kernel distributions. Results suggest that the MPI is robust when compared multidimensional cutoffs. The MPI box-plot maps suggest that poor people are located in Antioquia’s peripheral areas. Kernel distributions show that areas most affected by conflict tend to show higher levels of multidimensional poverty
    corecore