2,017 research outputs found

    Melt-spun nanocomposite fibers reinforced with aligned tunicate nanocrystals

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    The fabrication of nanocomposite films and fibers based on cellulose nanocrystals (P-tCNCs) and a thermoplastic polyurethane (PU) elastomer is reported. High-aspect-ratio P-tCNCs were isolated from tunicates using phosphoric acid hydrolysis, which is a process that affords nanocrystals displaying high thermal stability. Nanocomposites were produced by solvent casting (films) or melt-mixing in a twin-screw extruder and subsequent melt-spinning (fibers). The processing protocols were found to affect the orientation of both PU hard segments and the P-tCNCs within the PU matrix and therefore the mechanical properties. While the films were isotropic, both the polymer matrix and the P-tCNCs proved to be aligned along the fiber direction in the fibers, as shown using SAXS/WAXS, angle-dependent Raman spectroscopy, and birefringence analysis. Tensile tests reveal that fibers and films, at similar P-tCNC contents, display Young’s moduli and strain-at-break that are within the same order of magnitude, but the stress-at-break was found to be ten-times higher for fibers, conferring them a superior toughness over films

    Contribución a un futuro sostenible. Una dimensión necesaria y posible en toda acción e investigación educativa

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    El estudio de los errores conceptuales, preconcepciones, concepciones alternativas, etc., ha constituido posiblemente la línea de investigación más desarrollada en didáctica de las ciencias. Miles de artículos publicados lo atestiguan (Duit, 2004). Sin embargo, la inmensa mayoría de estos trabajos se centra en conceptos concretos de los distintos campos de la ciencia y, en cambio, apenas si se ha prestado atención a otras concepciones, tanto del alumnado como del profesorado, con notable influencia en el proceso de enseñanza/ aprendizaje, como las referidas a la naturaleza de la ciencia y, más particularmente, a las relaciones CTSA. Para ver en qué medida este reduccionismo persiste hoy en día hemos procedido a plantear a 50 investigadores en el área de las concepciones alternativas estas dos cuestiones: 1) Cuáles son las preconcepciones cuyo estudio le ha resultado de mayor interés. 2) Qué otras preconcepciones considera que convendría abordar o profundizar. La superación de este reduccionismo nos parece esencial por dos razones: En primer lugar, porque la construcción de la Didáctica de las Ciencias como un cuerpo coherente de conocimientos exige la superación de los tratamientos puntuales y el establecimiento de relaciones entre las diferentes áreas de investigación, integrando los resultados convergentes que se obtienen en las mismas. Y, por otra parte, ello puede contribuir a dar respuesta a la demanda de Naciones Unidas para que toda la educación contribuya a formar ciudadanas y ciudadanos conscientes de la situación de emergencia planetaria y preparados para la toma fundamentada de decisiones. Porque ello exige, entre otras cosas, estudiar las concepciones iniciales en este campo del profesorado y del alumnado y sacar a la luz los posibles obstáculos y los puntos de apoyo. Pero no se trata únicamente de esta línea de investigación: muchas otras permiten incorporar la atención a la situación del mundo como un elemento enriquecedor para lograr una educación científica de calidad y una contribución útil para la educación para la sostenibilidad

    Rendering polyurethane hydrophilic for efficient cellulose reinforcement in melt-spun nanocomposite fibers

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    Many commodity plastics, such as thermoplastic polyurethanes (PUs), require reinforcement for use as commercial products. Cellulose nanocrystals (CNCs) offer a “green” and scalable approach to polymer reinforcement as they are exceptionally stiff, recyclable, and abundant. Unfortunately, achieving efficient CNC reinforcement of PUs with industrial melt processing techniques is difficult, mostly due to the incompatibility of the hydrophobic PU with hydrophilic CNCs, limiting their dispersion. Here, a hydrophilic PU is synthesized to achieve strong reinforcement in melt‐processed nanocomposite fibers using filter paper‐sourced CNCs. The melt‐spun fibers, exhibiting smooth surfaces even at high CNC loading (up to 25 wt%) indicating good CNC dispersion, are bench‐marked against solvent‐cast films—solvent processing is not scalable but disperses CNCs well and produces strong CNC reinforcement. Mechanical analysis shows the CNC addition stiffens both nanocomposite films and fibers. The stress and strain at break, however, are not significantly affected in films, whereas adding CNCs to fibers increases the stress‐at‐break while reducing the strain‐at‐break. Compared to earlier studies employing a hydrophobic (and stiffer) PU, CNC addition to a hydrophilic PU substantially increases the fiber stiffness and strength. This work therefore suggests that rendering thermoplastics more hydrophilic might pave the way for “greener” polymer composite products using CNCs

    Sensitive detection of SARS-CoV-2 seroconversion by flow cytometry reveals the presence of nucleoprotein-reactive antibodies in unexposed individuals

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    There is an ongoing need of developing sensitive and specific methods for the determination of SARS-CoV-2 seroconversion. For this purpose, we have developed a multiplexed flow cytometric bead array (C19BA) that allows the identification of IgG and IgM antibodies against three immunogenic proteins simultaneously: the spike receptor-binding domain (RBD), the spike protein subunit 1 (S1) and the nucleoprotein (N). Using different cohorts of samples collected before and after the pandemic, we show that this assay is more sensitive than ELISAs performed in our laboratory. The combination of three viral antigens allows for the interrogation of full seroconversion. Importantly, we have detected N-reactive antibodies in COVID-19-negative individuals. Here we present an immunoassay that can be easily implemented and has superior potential to detect low antibody titers compared to current gold standard serology methods.Acknowledgements: We thank Petros Tyrakis and Iván Martínez-Forero for critical reading and editing of the manuscript. Support was provided by the Severo Ochoa Excellence Accreditation from MCIU (SEV-2016-0644) and the SPRI I+D COVID-19 fund (Gobierno Vasco). Personal fellowships: A.A.-V. (La Caixa Inphinit LCF/BQ/DR20/11790022), A.B. (AECC Bizkaia), A.G.d.R (Bikaintek), A.P. (Ramón y Cajal), B.J.-L. (Gob. Vasco), and E.P.-F. (Juan de la Cierva-Formación). M.L.M.-C. acknowledges RTC2019-007125-1, DTS20/00138, SAF2017-87301-R, and BBVA UMBRELLA project. M.L.-H. acknowledges the ISCIII for grant COV20-0170 and the Government of Cantabria for grant 2020UIC22-PUB-0019. O.M., J.-M.M., and N.G.A.A. acknowledge the Agencia Estatal de Investigación (Spain) for grants CTQ2015-68756-R, RTI2018-101269-BI00, and RTI2018-095700-B-I00, respectively. A.P. has received grant funding from the European Research Council (ERC), grant agreement number 804236 (Horizon 2020), and the FERO Foundation

    Radar on RAIA: High frequency radars in the RAIA Observatory

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    The RADAR ON RAIA project aims to update and extend beyond the Galician border the High Frequency (HF) radar network that has been operating since 2011 in the framework of the RAIA Observatory. The Project is allowing the establishment of a cross-border collaboration beyond the physical infrastructure itself, developing a sharing strategy of maintenance procedures, validation and data processing on both sides of the border, as well as an easy and public access to all the information. In addition, new products are being developed to exploit the potential of the HF radar technology.Peer Reviewe

    uma análise transversal

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    Publisher Copyright: Copyright © Ordem dos Médicos 2022.Introduction: Pre-exposure prophylaxis (PrEP) has gained relevance as a method of prevention for HIV in certain people and settings. Following the publication of the guideline on PrEP prescribing in Portugal, we aimed to assess the knowledge of Portuguese Medical Students about PrEP. Material and Methods: An online survey was sent to Medical students of Portuguese Medical Schools. We conducted a descriptive analysis of the results and an analytic cross-sectional study to identify factors associated with “knowing about PrEP”, “having had one class about PrEP” and “identifying eligible groups correctly”. Results: Of the 796 students that responded to the survey, 64.6% were aware of what PrEP is. Of these, 34.44% acquired this knowledge during their training. Out of the total amount of respondents, 4.77% could identify correctly and completely the eligible groups for PrEP. As the training years went by, the probability of being aware of PrEP, having had one class about PrEP, and identifying the eligible groups correctly, increased. Of the sixth-year students, 43.48% had had one class about PrEP and among the students that were aware of PrEP, 28% identified what the eligible groups were. After adjusting for the school year, we found differences between Medical Schools regarding the outcomes. The association between the different ways of knowing about PrEP and the ability to correctly identify eligible groups for PrEP was not statistically significant. Conclusion: The differences between Medical Schools could be harmonized through changes in the medical curricula that would allow for this topic to be addressed more often.publishersversionpublishe

    RADAR ON RAIA: High frequency radars in the RAIA Observatory

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    9th International Workshop on Marine Technology (MARTECH), virtual, 16-18 June 2021The RADAR ON RAIA project aims to update and extend beyond the Galician border the High Frequency (HF) radar network that has been operating since 2011 in the framework of the RAIA Observatory. The Project is allowing the establishment of a cross-border collaboration beyond the physical infrastructure itself, developing a sharing strategy of maintenance procedures, validation and data processing on both sides of the border, as well as an easy and public access to all the information. In addition, new products are being developed to exploit the potential of the HF radar technologyN

    Avaliação da qualidade de vida com o instrumento SF-36 em lombalgia crônica

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    OBJETIVO: Avaliar a qualidade de vida através dos domínios do Instrumento SF-36 em portadores de lombalgia crônica inespecífica. MÉTODOS: Trinta portadores de lombalgia crônica inespecífica foram aleatorizados para três grupos (grupo Iso (Isostretching), grupo RPG (Reeducação Postural Global) e Iso+RPG), e avaliados quanto à dor e qualidade de vida antes e após as intervenções fisioterápicas e reavaliados novamente após 2 meses de acompanhamento. Após a aceitação do Termo de Consentimento Livre e Esclarecido os pacientes foram submetidos a procedimentos como: avaliação fisioterápica através do Instrumento de Avaliação da Coluna Vertebral, Escala Visual Analógica de Dor (EVA), Questionário de Qualidade de Vida através do Instrumento SF-36, antes da 1ª sessão e após três meses de tratamento, e reavaliados 2 meses após o tratamento. RESULTADOS: Mostraram que ambas as técnicas fisioterápicas diminuíram a dor (p<0,001), porém quando foram associadas as duas técnicas (Iso + RPG) a melhora da dor foi significativamente maior, e na avaliação após dois meses de acompanhamento o método de RPG foi mais eficaz. Quanto à avaliação da qualidade de vida, as técnicas fisioterápicas foram eficazes após as intervenções (P<0,001), porém o método do Iso foi mais eficaz quando os pacientes foram reavaliados no acompanhamento. CONCLUSÃO: As técnicas fisioterápicas utilizadas neste estudo foram eficazes para tratar a lombalgia crônica inespecífica apresentada pelos pacientes, pois diminuíram a algia que os mesmos apresentavam e melhoraram a qualidade de vida segundo os domínios do Instrumento SF-36. Nível de Evidência II, Ensaio Clínico Controlado e Randomizado. ____________________________________________________________________________________ ABSTRACTThe objective of this study was to evaluate the quality of life (QL) with the use of the SF-36 Questionnaire in patients with chronic nonspecific low back pain (CNLBP). Thirty patients with CNLBP were randomly assigned to one of three groups (Iso group (Isostretching), GPR group (Global Postural Reeducation), and the Iso+GPR group. Patients underwent physical therapy assessment with the use of the Vertebral Spine Assessment, the Visual Analog Scale of Pain (VASP), and the SF-36 life quality questionnaire before the first session (first assessment), after three months of treatment (second assessment) and reassessed two months after the final session in the follow-up (third assessment). The results indicated that both physical therapy techniques reduced pain (p<0.001); when the techniques (Iso+GPR) were combined, the reduction in pain was significantly greater; and, in the follow-up assessment, the GPR method was more efficient. As for the QL, physical therapy techniques were effective after the interventions (p<0.001), and the Iso method was more effective when patients were reassessed in the follow-up. We conclude that the physical therapy techniques used in this study were efficient to treat CNLBP in the patients since they reduced pain and increased QL according to the results of the SF-36 questionnaire. Level of Evidence II, Randomized Controlled Clinical Trial

    Functional annotation of human long noncoding RNAs via molecular phenotyping

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    Long noncoding RNAs (lncRNAs) constitute the majority of transcripts in the mammalian genomes, and yet, their functions remain largely unknown. As part of the FANTOM6 project, we systematically knocked down the expression of 285 lncRNAs in human dermal fibroblasts and quantified cellular growth, morphological changes, and transcriptomic responses using Capped Analysis of Gene Expression (CAGE). Antisense oligonucleotides targeting the same lncRNAs exhibited global concordance, and the molecular phenotype, measured by CAGE, recapitulated the observed cellular phenotypes while providing additional insights on the affected genes and pathways. Here, we disseminate the largest-todate lncRNA knockdown data set with molecular phenotyping (over 1000 CAGE deep-sequencing libraries) for further exploration and highlight functional roles for ZNF213-AS1 and lnc-KHDC3L-2.Peer reviewe

    Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children

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    We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2
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