109 research outputs found
El fair play en la iniciación deportiva, un estudio con entrenadores de fútbol
El entrenamiento deportivo con jóvenes debe transmitir valores educativos desarrollando mecanismos de superación personal y respeto
hacia los adversarios con un entorno favorable hacia todos los agentes intervinientes. El objetivo de este estudio es detectar los comportamientos de los
entrenadores del fútbol base en competición que promueven el fair play. Utilizamos la metodología observacional, un instrumento de observación
SOCOFAP y un instrumento de registro LINCE, que nos ha permitido estudiar las conductas favorecedoras de este clima de juego limpio en el contexto
natural de la competición. La muestra está compuesta por cuatro entrenadores de fútbol, licenciados en educación física, que fueron filmados durante
cuatro partidos cada uno. Después de un análisis de patrones temporales (T-patterns) con el programa THEME detectamos; por un lado las conductas
promotoras de fair play más relevantes -elogios y ánimo a sus jugadores, incentivar la disculpa en faltas cometidas y aplaudir a los adversarios por sus
actuaciones favorables-, y por otro la relación entre ellas y el resultado del partido.Este trabajo forma parte de las investigaciones: Grup de recerca i innovació en dissenys (GRID). Tecnologia i aplicació multimèdia i digital als dissenys observacionals que ha sido subvencionado por la Generalitat de Cataluña durante el trienio 2009-2013. Observación de la interacción en deporte y actividad física: Avances técnicos y metodológicos en registros automatizados cualitativoscuantitativos, que ha sido subvencionado por la Secretaría de Estado de Investigación, Desarrollo e Innovación del Ministerio de Educación y Ciencia [DEP2012-32124], durante el trienio 2012-2016
Curvature-enhanced localised emission from dark states in wrinkled monolayer WSe2 at room temperature
Localised emission from defect states in monolayer transition metal
dichalcogenides is of great interest for optoelectronic and quantum device
applications. Recent progress towards high temperature localised emission
relies on the application of strain to induce highly confined excitonic states.
Here we propose an alternative paradigm based on curvature, rather than
in-plane stretching, achieved through free-standing wrinkles of monolayer
tungsten diselenide (WSe2). We probe these nanostructures using tip-enhanced
optical spectroscopy to reveal the spatial localisation of out-of-plane
polarised emission from the WSe2 wrinkles. Based on the photoluminescence and
Raman scattering signatures resolved with nanoscale spatial resolution, we
propose the existence of a manifold of spin-forbidden excitonic states that are
activated by the local curvature of the WSe2. We are able to access these dark
states through the out-of-plane polarised surface plasmon polariton resulting
in enhanced strongly localised emission at room temperature, which is of
potential interest for quantum technologies and photonic devices
Pediatric joint hypermobility: a diagnostic framework and narrative review
BACKGROUND: Hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD) are debilitating conditions. Diagnosis is currently clinical in the absence of biomarkers, and criteria developed for adults are difficult to use in children and biologically immature adolescents. Generalized joint hypermobility (GJH) is a prerequisite for hEDS and generalized HSD. Current literature identifies a large proportion of children as hypermobile using a Beighton score ≥ 4 or 5/9, the cut off for GJH in adults. Other phenotypic features from the 2017 hEDS criteria can arise over time. Finally, many comorbidities described in hEDS/HSD are also seen in the general pediatric and adolescent population. Therefore, pediatric specific criteria are needed. The Paediatric Working Group of the International Consortium on EDS and HSD has developed a pediatric diagnostic framework presented here. The work was informed by a review of the published evidence. OBSERVATIONS: The framework has 4 components, GJH, skin and tissue abnormalities, musculoskeletal complications, and core comorbidities. A Beighton score of ≥ 6/9 best identifies children with GJH at 2 standard deviations above average, based on published general population data. Skin and soft tissue changes include soft skin, stretchy skin, atrophic scars, stretch marks, piezogenic papules, and recurrent hernias. Two symptomatic groups were agreed: musculoskeletal and systemic. Emerging comorbid relationships are discussed. The framework generates 8 subgroups, 4 pediatric GJH, and 4 pediatric generalized hypermobility spectrum disorders. hEDS is reserved for biologically mature adolescents who meet the 2017 criteria, which also covers even rarer types of Ehlers-Danlos syndrome at any age. CONCLUSIONS: This framework allows hypermobile children to be categorized into a group describing their phenotypic and symptomatic presentation. It clarifies the recommendation that comorbidities should be defined using their current internationally accepted frameworks. This provides a foundation for improving clinical care and research quality in this population
Developing highly reversible Li–CO2 batteries: from on-chip exploration to practical application
Li-CO2 batteries (LCBs) hold significant potential for meeting the energy transition requirements and mitigating global CO2 emissions. However, the development of efficient LCBs is still in its early stages, necessitating the search for highly effective electrocatalysts and a deeper understanding of their mechanisms. To address these challenges, we have designed a versatile on-chip electrochemical testing platform, which enables simultaneous catalyst screening and in-situ analysis of the chemical composition and morphological evolution of reaction products. Six different metal nanoparticle catalysts were evaluated and it was found that Pt-based LCBs demonstrated a low overpotential (∼0.55 V). The reaction pathways and reversible nature of the LCBs were studied using in situ electrochemical Raman spectroscopy and atomic force microscopy, and were supported by ab initio calculations. As a result of the platform studies, LCB coin cells and pouch cells were fabricated which demonstrated high capacity, stability, and an energy efficiency of up to 90%. A multimodal lab-on-a-chip platform has a wide range of applications in other systems, such as metal-air batteries, electrocatalysts, fuel cells, and photoelectrochemical systems, thereby opening up new opportunities for rapid catalyst screening, mechanism investigation, and the development of practical applications
Molecular Weight Tuning of Organic Semiconductors for Curved Organic-Inorganic Hybrid X-Ray Detectors
Curved X-ray detectors have the potential to revolutionize diverse sectors due to benefits such as reduced image distortion and vignetting compared to their planar counterparts. While the use of inorganic semiconductors for curved detectors are restricted by their brittle nature, organic-inorganic hybrid semiconductors which incorporated bismuth oxide nanoparticles in an organic bulk heterojunction consisting of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) are considered to be more promising in this regard. However, the influence of the P3HT molecular weight on the mechanical stability of curved, thick X-ray detectors remains less well understood. Herein, high P3HT molecular weights (>40 kDa) are identified to allow increased intermolecular bonding and chain entanglements, resulting in X-ray detectors that can be curved to a radius as low as 1.3 mm with low deviation in X-ray response under 100 repeated bending cycles while maintaining an industry-standard dark current of mu C Gy(-1) cm(-2). This study identifies a crucial missing link in the development of curved detectors, namely the importance of the molecular weight of the polymer semiconductors used
Multi-scale characterisation of a ferroelectric polymer reveals the emergence of a morphological phase transition driven by temperature
[EN] Ferroelectric materials exhibit a phase transition to a paraelectric state driven by temperature
- called the Curie transition. In conventional ferroelectrics, the Curie transition is caused by a
change in crystal symmetry, while the material itself remains a continuous three-dimensional
solid crystal. However, ferroelectric polymers behave differently. Polymeric materials are
typically of semi-crystalline nature, meaning that they are an intermixture of crystalline and
amorphous regions. Here, we demonstrate that the semi-crystalline morphology of the ferroelectric
copolymer of vinylidene fluoride and trifluoroethylene (P(VDF-TrFE)) strongly
affects its Curie transition, as not only a change in crystal symmetry but also in morphology
occurs. We demonstrate, by high-resolution nanomechanical measurements, that the semicrystalline
microstructure in the paraelectric state is formed by crystalline domains
embedded into a softer amorphous phase. Using in situ X-ray diffraction measurements, we
show that the local electromechanical response of the crystalline domains is counterbalanced
by the amorphous phase, effectively masking its macroscopic effect. Our quantitative multiscale
characterisations unite the nano- and macroscopic material properties of the ferroelectric
polymer P(VDF-TrFE) through its semi-crystalline nature.European Union’s Horizon 2020 research and Innovation programme under the Marie Skłodowska-Curie grant agreement number 721874 (SPM2.0). RG acknowledges funding from the European Research Council ERC–AdG–340177 (3DNanoMech). This work was supported by the UK government’s Department for Business, Energy and Industrial Strategy. The dynamic mechanical analysis was supported by T. Koch from the Institute of Materials Science and Technology, TU Wien. We gratefully thank A. Muhamedagić for the contribution of artworks to the figures (armindesign.li).Peer reviewe
Molecular weight tuning of organic semiconductors for curved organic–inorganic hybrid X‐ray detectors
Curved X-ray detectors have the potential to revolutionize diverse sectors due to benefits such as reduced image distortion and vignetting compared to their planar counterparts. While the use of inorganic semiconductors for curved detectors are restricted by their brittle nature, organic–inorganic hybrid semiconductors which incorporated bismuth oxide nanoparticles in an organic bulk heterojunction consisting of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) are considered to be more promising in this regard. However, the influence of the P3HT molecular weight on the mechanical stability of curved, thick X-ray detectors remains less well understood. Herein, high P3HT molecular weights (>40 kDa) are identified to allow increased intermolecular bonding and chain entanglements, resulting in X-ray detectors that can be curved to a radius as low as 1.3 mm with low deviation in X-ray response under 100 repeated bending cycles while maintaining an industry-standard dark current of <1 pA mm−2 and a sensitivity of ≈ 0.17 μC Gy−1 cm−2. This study identifies a crucial missing link in the development of curved detectors, namely the importance of the molecular weight of the polymer semiconductors used
Plasma antioxidant responses and oxidative stress following a soccer game in elite female players
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