644 research outputs found

    Using Direct Current Potential Drop Technique to Estimate Fatigue Crack Growth Rates in Solid Bar Specimens under Environmental Assisted Fatigue in Simulated Pressurized Water Reactor Conditions

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    ABSTRACT: The direct current potential drop (DCPD) technique may be used in crack propagation tests to measure the crack growth rate (CGR). Potential probes attached to the specimen allow the variation of the crack length to be estimated. In this research, the DCPD technique using one single potential probe was applied to solid bar specimens (i.e., without any initial notch or crack) subjected to low-cycle fatigue testing in a simulated pressurized water reactor (PWR) environment. This particular analysis had two associated difficulties, the first one being the fact that crack initiation sites are not known beforehand, and the second one consisting in the experimental difficulties and conditioning factors associated with the simulation of the PWR environment. Nine solid bar specimens were tested to fatigue failure under different strain amplitudes and frequencies, while also measuring the corresponding DCPD signal during the fatigue process. It was observed that the initiation of multiple cracks was detected by the DCPD measurements. Moreover, as fatigue continued, one of the cracks became dominant and progressed to cause the specimen failure. The DCPD technique allowed the average CGR of the dominant crack to be estimated. Finally, the obtained average CGRs were validated by comparing them with average CGRs derived from striation spacing measurements, obtained from scanning electron microscopy (SEM) and from literature values gathered in the NUREG/CR-6909 document.This project received funding from the Euratom Research and Training Programme 2014–2018 under Grant Agreement No. 662320 (INCEFA-PLUS) and Euratom Research & Training Programme 2019–2020 under grant agreement No. 945300 (INCEFA-SCALE)

    X-ray diffraction, thermal analysis, and Raman scattering study of K2BeF4 and comparation to other member of the (beta)-K2SO4 family with ferroelectric -paraelectric transition

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    Thermal analysis, powder diffraction, and Raman scattering as a function of the temperature were carried out on K2BeF4. Moreover, the crystal structure was determined at 293 K from powder diffraction. The compound shows a transition from Pna21 to Pnam space group at 921 K with a transition enthalpy of 5 kJ/mol. The transition is assumed to be first order because the compound shows metastability. Structurally and spectroscopically the transition is similar to those observed in (NH4)2SO4, which suggests that the low-temperature phase is ferroelectric. In order to confirm it, the spontaneous polarization has been computed using an ionic model

    Alcohol consumption in Spanish mental health patients vs. working population

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    Introduction: Alcohol consumption has a high prevalence in society and its chronic consumption is one of the main factors related to health condition in an individual, along with other aspects concerning lifestyle. Regarding the health-disease correlation, it is one of the main determinants of health, from an epidemiological point of view, and has been a traditional object of study from different perspectives and in diverse population groups.Objective: To compare consumption patterns and related variables in two different groups: patients in mental health units and workers in general.Materials and methods: Cross-sectional study in a population of 1 180 service workers and 304 patients in a mental health unit. Sociodemographic and work aspects, as well as pattern of alcohol consumption were analyzed for both populations.Results: Differences in both groups were observed regarding the number of consumers, quantity of consumption and type of beverages consumed, differences that disappear, in part, when comparing groups of workers of both population samples.Conclusions: Differences in the consumption pattern of both populations lead to different preventive-assistance strategies and to the need for implementing coordinated actions by specific programs among those affected.Introducción. El consumo de alcohol tiene una elevada prevalencia en la sociedad y su consumo crónico es uno de los principales factores relacionados con el estado de salud de los individuos, junto a otros aspectos concernientes al estilo de vida. Debido a su importancia, este tema ha sido objeto tradicional de estudio desde diferentes perspectivas epidemiológicas y en diversos colectivos poblacionales.Objetivo. Realizar una comparativa de patrones de consumo y variables relacionadas en dos colectivos diferenciados: pacientes de unidades de salud mental y trabajadores en general.Materiales y métodos. Estudio transversal realizado en una población de 1 180 trabajadores del sector servicios de la administración pública y 304 pacientes de una unidad de salud mental. Se analizaron variables sociodemográficas y laborales y el patrón de consumo de alcohol.Resultados. Existen diferencias en ambos colectivos en cuanto al número de consumidores, cantidad de consumo y tipo de bebidas consumidas, diferencias que desaparecen en parte cuando se comparan colectivos de trabajadores de ambas muestras poblacionales.Conclusiones. Las diferencias en el patrón de consumo de ambas poblaciones orientan hacia actuaciones preventivo-asistenciales distintas en ambos grupos y hacia una necesidad de implementar actuaciones coordinadas entre todos los afectados mediante programas específicos

    Ionic Conductivity and Potential Application for Fuel Cell of a Modified Imine-Based Covalent Organic Framework

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/jacs.7b05182We present the novel potential application of imine-based covalent organic frameworks (COFs), formed by the direct Schiff reaction between 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarbaldehyde building blocks in m-cresol or acetic acid, named RT-COF-1 or RT-COF-1Ac/RT-COF-1AcB. The post-synthetic treatment of RT-COF-1 with LiCl leads to the formation of LiCl@RT-COF-1. The ionic conductivity of this series of polyimine COFs has been characterized at variable temperature and humidity, using electrochemical impedance spectroscopy. LiCl@RT-COF-1 exhibits a conductivity value of 6.45 × 10-3 S cm-1 (at 313 K and 100% relative humidity) which is among the highest values so far reported in proton conduction for COFs. The mechanism of conduction has been determined using 1H and 7Li solid-state nuclear magnetic resonance spectroscopy. Interestingly, these materials, in the presence of controlled amounts of acetic acid and under pressure, show a remarkable processability that gives rise to quasi-transparent and flexible films showing in-plane structural order as confirmed by X-ray crystallography. Finally, we prove that these films are useful for the construction of proton exchange membrane fuel cells (PEMFC) reaching values up to 12.95 mW cm-2 and 53.1 mA cm-2 for maximum power and current density at 323 K, respectivelyWe thank the MINECO (Spain) for financial support through Juan de la Cierva postdoctoral fellowship. We thank the Spanish Ministry of Economy (MAT2016-77608-C3-1-P, MAT2013-46753-C2-1-P, CTQ2014-53486-R, ENE2016-77055-C3-1-R), and Comunidad de Madrid (S2013/MAE2882) for generous fundin

    Designing for shape memory in additive manufacturing of Cu-Al-Ni shape memory alloy processed by laser powder bed fusion

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    Shape memory alloys (SMAs) are functional materials that are being applied in practically all industries, from aerospace to biomedical sectors, and at present the scientific and technologic communities are looking to gain the advantages offered by the new processing technologies of additive manufacturing (AM). However, the use of AM to produce functional materials, like SMAs, constitutes a real challenge due to the particularly well controlled microstructure required to exhibit the functional property of shape memory. In the present work, the design of the complete AM processing route, from powder atomization to laser powder bed fusion for AM and hot isostatic pressing (HIP), is approached for Cu-Al-Ni SMAs. The microstructure of the different processing states is characterized in relationship with the processing parameters. The thermal martensitic transformation, responsible for the functional properties, is analyzed in a comparative way for each one of the different processed samples. The present results demonstrate that a final post-processing thermal treatment to control the microstructure is crucial to obtain the expected functional properties. Finally, it is demonstrated that using the designed processing route of laser powder bed fusion followed by a post-processing HIP and a final specific thermal treatment, a satisfactory shape memory behavior can be obtained in Cu-Al-Ni SMAs, paving the road for further applications

    REE geochemistry of neogene–holocene sediments of La Fontanilla Cove (Tinto Estuary, SW Spain)

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    The Tinto and Odiel rivers (SW Spain) drain from a vast sulfide mining district and join at a 20-km-long estuary that enters the Atlantic Ocean. In this work, the contents of rare earth elements (REE) and fractionation in Neogene–Holocene sediment cores from La Fontanilla cove (Tinto estuary) were studied. The sediments were collected from a depth of 18 m at different distances from the recent river flow and were analyzed for new information on the temporal development of the REE load in the sediment column. Results show that the ∑ REE is higher in the finer sediments and during periods of mining activity from prehistoric to recent times. Marine influence appears to increase the light REE (LREE) relative to the heavy REE (HREE). The REE patterns of these estuarine sediments show convex curvatures in the MREE relative to the LREE and HREE, indicating the presence of acid-mixing processes between the fluvial waters affected by acid mine drainage (AMD) and seawater, as well as the precipitation of poorly crystalline mineral phases. Significant positive Eu anomalies were found in ebb-tide channels and marsh deposits, which can reflect the mineralogical composition and/or a strong localized salinity gradient combined with organic matter degradation. Sedimentological characteristics of the deposits appear to play the main role in accumulation and fractionation of the RE

    A large, ten-generation family with autosomal dominant preaxial polydactyly/triphalangeal thumb: Historical, clinical, genealogical, and molecular studies

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    We present a large, ten-generation family of 273 individuals with 84 people having preaxial polydactyly/triphalangeal thumb due to a pathogenic variant in the zone of polarizing activity regulatory sequence (ZRS) within the exon 5 of LMBR1. The causative change maps to position 396 of the ZRS, located at position c.423 + 4909C > T (chr7:156791480; hg38; LMBR1 ENST00000353442.10; rs606231153 NG_009240.2) in the intron 5 of LMBR1. The first affected individual with the disorder was traced back to mid-1700, when some settlers and workers established in Cervera de Buitrago, a small village about 82 km North to Madrid. Clinical and radiological studies of most of the affected members have been performed for 42 years (follow-up of the family by LFGA). Molecular studies have confirmed a pathogenic variant in the ZRS that segregates in this family. To the best of our knowledge, this is the largest family with preaxial polydactyly/triphalangeal thumb reported so far.Instituto de Salud Carlos III, Grant/Award Number: PI20/0105

    COVID-19 Clinical Profile in Latin American Migrants Living in Spain: Does the Geographical Origin Matter?

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    COVID-19; Latin America; SeverityCOVID-19; Amèrica Llatina; GravetatCOVID-19; América Latina; GravedadThe aim of this study was to describe and compare the clinical characteristics of hospitalized patients with COVID-19 pneumonia according to their geographical origin. This is a retrospective case-control study of hospitalized patients with confirmed COVID-19 pneumonia treated at Vall d’Hebron University Hospital (Barcelona) during the first wave of the pandemic. Cases were defined as patients born in Latin America and controls were randomly selected among Spanish patients matched by age and gender. Demographic and clinical variables were collected, including comorbidities, symptoms, vital signs and analytical parameters, intensive care unit admission and outcome at 28 days after admission. Overall, 1080 hospitalized patients were registered: 774 (71.6%) from Spain, 142 (13.1%) from Latin America and the rest from other countries. Patients from Latin America were considered as cases and 558 Spanish patients were randomly selected as controls. Latin American patients had a higher proportion of anosmia, rhinorrhea and odynophagia, as well as higher mean levels of platelets and lower mean levels of ferritin than Spanish patients. No differences were found in oxygen requirement and mortality at 28 days after admission, but there was a higher proportion of ICU admissions (28.2% vs. 20.2%, p = 0.0310). An increased proportion of ICU admissions were found in patients from Latin America compared with native Spanish patients when adjusted by age and gender, with no significant differences in in-hospital mortality.Isabel Campos-Varela’s research activity is funded by grant PI19/00330 from Instituto de Salud Carlos III. CIBERehd is supported by Instituto de Salud Carlos III. The work was independent of all funding. This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors

    Cognitive insight in first-episode psychosis : changes during Metacognitive Training

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    Altres ajuts: The project has been funded by the Instituto de Salud Carlos III (Spanish Government); by the Fondo Europeo de Desarrollo Regional (FEDER), Progress and Health Foundation of the Andalusian Regional Ministry of Health, grant PI-0634/2011; Obra Social La Caixa (RecerCaixa call 2013); and Obra Social Sant Joan de Déu (BML).Background: Metacognitive training (MCT) has demonstrated its efficacy in psychosis. However, the effect of each MCT session has not been studied. The aim of the study was to assess changes in cognitive insight after MCT: (a) between baseline, post-treatment, and follow-up; (b) after each session of the MCT controlled for intellectual quotient (IQ) and educational level. Method: A total of 65 patients with first-episode psychosis were included in the MCT group from nine centers of Spain. Patients were assessed at baseline, post-treatment, and 6 months follow-up, as well as after each session of MCT with the Beck Cognitive Insight Scale (BCIS). The BCIS contains two subscales: self-reflectiveness and self-certainty, and the Composite Index. Statistical analysis was performed using linear mixed models with repeated measures at different time points. Results: Self-certainty decreased significantly (p = 0.03) over time and the effect of IQ was negative and significant (p = 0.02). From session 4 to session 8, all sessions improved cognitive insight by significantly reducing self-certainty and the Composite Index. Conclusions: MCT intervention appears to have beneficial effects on cognitive insight by reducing self-certainty, especially after four sessions. Moreover, a minimum IQ is required to ensure benefits from MCT group intervention

    Beneficial effect of ursodeoxycholic acid in patients with acyl-CoA oxidase 2 (ACOX2) deficiency-associated hypertransaminasemia

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    Background and aims: A variant (p.Arg225Trp) of peroxisomal acyl-CoA oxidase 2 (ACOX2), involved in bile acid (BA) side-chain shortening, has been associated with unexplained persistent hypertransaminasemia and accumulation of C27-BAs, mainly 3?,7?,12?-trihydroxy-5?-cholestanoic acid (THCA). We aimed to investigate the prevalence of ACOX2 deficiency-associated hypertransaminasemia (ADAH), its response to ursodeoxycholic acid (UDCA), elucidate its pathophysiological mechanism and identify other inborn errors that could cause this alteration. Methods and results: Among 33 patients with unexplained hypertransaminasemia from 11 hospitals and 13 of their relatives, seven individuals with abnormally high C27-BA levels (>50% of total BAs) were identified by high-performance liquid chromatography-mass spectrometry. The p.Arg225Trp variant was found in homozygosity (exon amplification/sequencing) in two patients and three family members. Two additional nonrelated patients were heterozygous carriers of different alleles: c.673C>T (p.Arg225Trp) and c.456_459del (p.Thr154fs). In patients with ADAH, impaired liver expression of ACOX2, but not ACOX3, was found (immunohistochemistry). Treatment with UDCA normalized aminotransferase levels. Incubation of HuH-7 hepatoma cells with THCA, which was efficiently taken up, but not through BA transporters, increased reactive oxygen species production (flow cytometry), endoplasmic reticulum stress biomarkers (GRP78, CHOP, and XBP1-S/XBP1-U ratio), and BAX? expression (reverse transcription followed by quantitative polymerase chain reaction and immunoblot), whereas cell viability was decreased (tetrazolium salt-based cell viability test). THCA-induced cell toxicity was higher than that of major C24-BAs and was not prevented by UDCA. Fourteen predicted ACOX2 variants were generated (site-directed mutagenesis) and expressed in HuH-7 cells. Functional tests to determine their ability to metabolize THCA identified six with the potential to cause ADAH. Conclusions: Dysfunctional ACOX2 has been found in several patients with unexplained hypertransaminasemia. This condition can be accurately identified by a noninvasive diagnostic strategy based on plasma BA profiling and ACOX2 sequencing. Moreover, UDCA treatment can efficiently attenuate liver damage in these patients.Funding information: This study was supported by the following grants: CIBERehd (EHD15PI05/2016); Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain (PI19/00819 and PI20/00189), co-funded by European Regional Development Fund/European Social Fund, “Investing in your future”; “Junta de Castilla y León” (SA074P20); Fundació Marato TV3 (201916–31); AECC Scientific Foundation (2017/2020), Spain; and “Centro Internacional sobre el Envejecimiento” (OLD-HEPAMARKER, 0348_CIE_6_E), Spain. We also acknowledge support from grants PID2019-111669RBI-100, PID2020-115055RB-I00 from Plan Nacional de I+D funded by the “Agencia Estatal de Investigación” (AEI) and the center grant P50AA011999 Southern California Research Center for ALPD and Cirrhosis funded by NIAAA/NIH, as well as support from AGAUR of the “Generalitat de Catalunya” SGR-2017-1112, European Cooperation in Science & Technology (COST) ACTION CA17112 Prospective European Drug-Induced Liver Injury Network. Marta Alonso-Peña was the recipient of a predoctoral fellowship from “Ministerio de Educación, Cultura y Deporte” (BOE-A-2015-9456; FPU-14/00214) and a Mobility Grant for Short Stays from “Ministerio de Ciencia, Innovación y Universidades” (EST17/00186). Ricardo Espinosa-Escudero is the recipient of a predoctoral fellowship from “Junta de Castilla y León” and “Fondo Social Europeo” (EDU/574/2018). The funding sources were not involved in the research design or preparation of the article
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