The El Guijo Pluton: petrology, geochemistry, age and relation to others rocks of Los Pedroches batholith

[Resumen] El plutón de El Guijo es uno de los plutones ácidos circunscritos, intrusivos en las granodioritas que constituyen los tercios central y occidental del batolito de Los Pedroches. Con forma subelíptica, presenta una zonación centrípeta que va desde facies marginales graníticas biotíticas (localmente con microadamellitas porfídicas), marcadamente porfídicas, hasta facies centrales de leucogranitos cordieríticos (± moscovita). Geoquímicamente, las rocas de este plutón definen una asociación peraluminosa, con evolución netamente calcoalcalina. Se presentan los resultados de una datación (Rb-SR, roca total) que definen una isocrona de 300 ± 6 Ma, con (87 Sr/86 Sr) o de 0.704. Finalmente, se discuten sus relaciones y significado en el contexto general del batolito de Los Pedroches.[Abstract] The El Guijo pluton belongs to a group of centred, acidic plutons which intrude the ranodiorites making the most part of the Pedroches Batholith central and western thirds. It has a sub-elliptical shape and shows a centripetal zonation which ranges between marginal, biotite-bearing porphyritic granitic facÍes (locally intruding porphyritic micro-adamellites) and central cordierite -bearing leucogranites (± muscovite). They collectively define a peraluminous association with a neat calcalkaline evolution. The results of a Rb-Sr whole-rock study are presented. These define a 300 ±6 Ma age isochron with (87 Sr/86 Sr) o = 0.704. Finally, its relationships with, and its significance in the context of the overall Pedroches Batholith are discused

Insights into the room temperature magnetism of ZnO/Co3O4 mixtures

The origin of room temperature (RT) ferromagneticlike behavior in ZnO-based diluted magnetic semiconductors is still an unclear topic. The present work concentrates on the appearance of RT magnetic moments in just mixed ZnO/Co3O4 mixtures without thermal treatment. In this study, it is shown that the magnetism seems to be related to surface reduction of the Co3O4 nanoparticles, in which, an antiferromagnetic Co3O4 nanoparticle (core) is surrounded by a CoO-like shell. This singular superficial magnetism has also been found in other mixtures with semiconductors such as TiO2 and insulators such as Al2O3

Expanding the tunability and applicability of exchange-coupled/decoupled magnetic nanocomposites

CoFe2O4/Co-Fe magnetic composites are usually prepared through partial reduction of CoFe2O4, which often yields monoxides (i.e., FeO, CoO) as secondary phases. Since these compounds are paramagnetic at ambient conditions, the presence of a small amount of monoxide is generally downplayed in the literature, and the possible effects on the magnetic properties are simply ignored. However, the present study shows that even a low concentration of monoxide results in decoupling of the soft and hard magnetic phases, which inevitably leads to a deterioration of the magnetic properties. Additionally, it is confirmed that a partial reduction of CoFe2O4 is a suitable method to produce CoFe2O4/Co-Fe nanocomposites, provided that the treatment is well controlled with respect to duration, temperature and flow of reductant. A monoxide-free nanocomposite was produced and its magnetic properties evaluated both at room and low temperature. Our model system exemplifies the potential of exchange-coupling (and decoupling) as a tool to tune the magnetic properties of a material within a relatively wide range of values, thus widening its spectrum of potential applications

Exposure to perfluoroalkyl substances (PFAS) and association with thyroid hormones in adolescent males

Background: Perfluoroalkyl substances (PFAS) are found in a wide range of consumer products. Exposure to PFAS in children and adolescents may be associated with alterations in thyroid hormones, which have critical roles in brain function. Objective: This study investigated the association between plasma concentrations of PFAS and serum levels of total triiodothyronine (T3), free thyroxine (T4), and thyroid-stimulating hormone (TSH) in adolescent males. Methods: In 2017–2019, 151 boys from the Environment and Childhood (INMA)-Granada birth cohort, Spain, participated in a clinical follow up visit at the age of 15–17 years. Plasma concentrations of ten PFAS (PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, PFOS, and PFHxS) and serum thyroid hormones were measured in 129 of these boys. Linear regression analysis was performed to determine associations of individual PFAS with total T3, free T4, TSH, and free T4/TSH ratio, and quantile g-computation models were performed to assess the mixture effect. Additional models considered iodine status as effect modifier. Results: PFOS was the most abundant PFAS in plasma (median = 2.22 μg/L), followed by PFOA (median = 1.00 μg/L), PFNA (median = 0.41 μg/L), and PFHxS (median = 0.40 μg/L). When adjusted by confounders (including age, maternal schooling, and fish intake), PFOA and PFUnDA were associated with an increase in free T4 (β [95% CI] = 0.72 [0.06; 1.38] and 0.36 [0.04; 0.68] pmol/L, respectively, per two-fold increase in plasma concentrations), with no change in TSH. PFOS, the sum of PFOA, PFNA, PFOS, and PFHxS, and the sum of long-chain PFAS were marginally associated with increases in free T4. Associations with higher free T4 and/or total T3 were seen for several PFAS in boys with lower iodine intake (<108 μ/day) alone. Moreover, the PFAS mixture was association with an increase in free T4 levels in boys with lower iodine intake (% change [95% CI] = 6.47 [–0.69; 14.11] per each quartile increase in the mixture concentration). Conclusions: Exposure to PFAS, considered individually or as a mixture, was associated with an increase in free T4 levels in boys with lower iodine intake. However, given the small sample size, the extent of these alterations remains uncertainSpanish Consortium for Research on Epidemiology and Public Health (CIBERESP)Instituto de Salud Carlos III (ISCIII) (grant no. CP16/00085

Petrology and geochemistry of Cardeña-Virgen de La Cabeza pluton (batholith of Los Pedroches)

[Resumen] El plutón de Cardeña-Virgen de La Cabeza es uno de los cuerpos intrusivos que integran la unidad granítica del batolito de Los Pedroches. Dentro de este plutón, se ha establecido el emplazamiento sucesivo en el tiempo de: 1) adamellitas biotíticas, 2) granitos biotíticos porfídicos ± cordierita, 3) leucogranitos ± cordierita. Las adamellitas biotíticas muestran localmente paso gradual hacia las facies granodioríticas del batolito. Existe además un importante complejo filoniano que se intruye posteriormente, formado por diques riodacíticos de dirección NO-SE, lamprófidos, aplitas, pegmatitas y filones mineralizados· de cuarzo. Geoquímicamente, la adamellita y el granito biotítico porfídico constituyen una asociación alumino-cafémica de carácter calcoalcalino. Los enclaves anfibólicos (términos cafémicos) poseen carácter metaaluminoso. Los leucogranitos se desvían de la tendencia general definiendo una asociación aluminosa y leucocrática. Los diagramas de variación para elementos mayores, menores, trazas y tierras.raras de adamellitas, granitos biotíticos porfídicos y de granodioritas, rocas, estas últimas, con las que se encuentran íntimamente relacionadas, son compatibles con procesos de diferenciación magmática por cristalización fraccionada a partir de un magma inicial de composición granodiorítica más básico[Abstract] The Cardeña-Virgen de La Cabeza intrusion belongs to the granitic unit of the Los Pedroches batholith. the chronology of the intrusion of the different rocktypes that make up the pluton is as follows: 1) biotitic adamellite, 2) porphyritic, cordierite-bearing, biotitic granite. 3) cordierite bearing leucogranite. The biotitic adamellite locally shows a transition to the granodioritic facies of the batholith. A great amount ofNW-SW oriented dikes with rhyodacitic composition intruded subsequently. Lampophyres, aplites, pegmatites and ore-bearing quartz veins complete the dike complexo Adamellite and biotitic ganite define an aluminous-cafemic association with calcalkaline affinity. The amphibole-bearing enclaves represent the cafemic terms of the series and have a metaaluminous character.The leucogranite deviates from the general trend defining and aluminous, leucocratic association. Variation diagrams for major, minor and trace elements, including REE, of adamallite, porphyritic biotitic granite and granodiorite of the main pluton (which is intimately associated with the Cardeña-Virgen de La Cabeza intrusion) suggest a process of magmatic differentiation through fractional crystallization starting from a slightly more basic granodioritic magma

Evaluación de la competencia clínica de tutores de residentes de medicina familiar y comunitaria

ObjetivoDescribir la primera experiencia de una evaluación clínica objetiva y estructurada (ECOE) a tutores de residentes realizada en la comunidad autónoma de AndalucíaDiseñoObservacional descriptivoEmplazamientoUnidad Docente de Medicina Familiar y Comunitaria de HuelvaParticipantesTutores de residentes de medicina familiar y comunitariaMediciones principalesLos componentes competenciales que se consensuaron y ponderaron fueron los siguientes: anamnesis, exploración física, comunicación,habilidades técnicas, manejo, atención a la familia y actividades preventivas. La selección de las 10 situaciones clínicas de las que constaba la prueba se realizó utilizando unos criterios de priorización según la prevalencia, gravedad clínica, importancia de la prevención y del diagnóstico precoz, complejidad del caso, evaluación de la capacidad resolutiva del médico y simplicidad evaluativaResultadosRealizaron la ECOE 13 tutores. La edad media ± desviación estándar de los participantes fue de 42,8 ± 3,64 años. La prueba tuvo un coeficiente de fiabilidad (alfa de Cronbach) de 0,73. Por lo que se refiere a los resultados por participantes, la media global fue de 73 ± 6,2. Al analizar los resultados para los diferentes componentes competenciales, los mejores resultados se obtuvieron en la atención a la familia, la comunicación y las habilidades técnicasConclusionesLas pruebas de evaluación clínica objetiva y estructurada pueden ser útiles para la valoración de los tutores, con el objetivo de orientar su formación en los puntos débiles e incluso para, en un futuro no muy lejano, servir como instrumento para acreditar y reacreditar a los tutores de residentes de medicina familiar y comunitariaObjectivesWe show the first experience of the application of an objetive and structured clinical evaluation (OSCE) procedure to family medicine trainers, that has been carried out in Andalucia. The objective is to use a competence evaluation instrument that, in the short term, will be used not only for trainer accreditation but also for other public sanitary professionalsParticipantsTutors of family and commnity medicine residentsDesignObservational descriptiveSettingEducational unity of family medicinePrincipal measurementsThe competencial components to be assessed are the following: anamnesis, physical exploration, communication, technical skill, management, family attention y preventive activities. The clinical situations were selected using the following priority criteria: prevalence, clinical gravity, prevention and early diagnosis importance, case complexity, doctor's capacity of evaluation and simplicityResultsThirteen family medicine trainers took part in the OSCE. Their average age was 42.8±3.6 years. The test had an overall reliability coefficient (Cronbach's alpha) of 0.73. The overall mean score of the participants was 73±6.2. The best results about the competencial components were family attention, communication and technical skillConclusionsThe OSCE can be a convenient tool for family medical trainer evaluation, helping to orientate their education in the weak points and, in the near future, it can also be used as an instrument do accredit family medicine trainer

FeCo Nanowire-Strontium Ferrite Powder Composites for Permanent Magnets with High-Energy Products

Due to the issues associated with rare-earth elements, there arises a strong need for magnets with properties between those of ferrites and rare-earth magnets that could substitute the latter in selected applications. Here, we produce a high remanent magnetization composite bonded magnet by mixing FeCo nanowire powders with hexaferrite particles. In the first step, metallic nanowires with diameters between 30 and 100 nm and length of at least 2 {\mu}m are fabricated by electrodeposition. The oriented as-synthesized nanowires show remanence ratios above 0.76 and coercivities above 199 kA/m and resist core oxidation up to 300 {\deg}C due to the existence of a > 8 nm thin oxide passivating shell. In the second step, a composite powder is fabricated by mixing the nanowires with hexaferrite particles. After the optimal nanowire diameter and composite composition are selected, a bonded magnet is produced. The resulting magnet presents a 20% increase in remanence and an enhancement of the energy product of 48% with respect to a pure hexaferrite (strontium ferrite) magnet. These results put nanowire-ferrite composites at the forefront as candidate materials for alternative magnets for substitution of rare earths in applications that operate with moderate magnet performance

Hexaferrite-based permanent magnets with upper magnetic properties by cold sintering process via a non-aqueous solvent

The incessant technological pursuit towards a more sustainable and green future depends strongly on permanent magnets. At present, their use is widespread, making it imperative to develop new processing methods that generate highly competitive magnetic properties reducing the fabrication temperatures and costs. Herein, a novel strategy for developing dense sintered magnets based on Sr-hexaferrites with upper functional characteristics is presented. An innovative cold sintering approach using glacial acetic acid as novelty, followed by a post-annealing at 1100 {\deg}C, achieves a densification of the ceramic magnets of 92% with respect to the theoretical density and allows controlling the particle growth. After the cold sintering process, a fraction of amorphous SrO is identified, in addition to a partial transformation to {\alpha}-Fe2O3 as secondary crystalline phase. 46 wt% of SrFe12O19 remains, which is mostly recuperated after the post-thermal treatment. These findings do not significantly modify the final structure of ferrite magnets, neither at short- nor long-range order. The innovative process has a positive impact on the magnetic properties, yielding competitive ferrite magnets at lower sintering temperatures with an energy efficiency of at least 25%, which opens up a new horizon in the field of rare-earth free permanent magnets and new possibilities in other applications

Quantifying Li-content for compositional tailoring of lithium ferrite ceramics

Owing to their multiple applications, lithium ferrites are relevant materials for several emerging technologies. For instance, LiFeO2 has been spotted as an alternative cathode material in Li-ion batteries, while LiFe5O8 is the lowest damping ferrite, holding promise in the field of spintronics. The Li-content in lithium ferrites has been shown to greatly affect the physical properties, and in turn, the performance of functional devices based on these materials. Despite this, lithium content is rarely accurately quantified, as a result of the low number of electrons in Li hindering its identification by means of routine materials characterization methods. In the present work, magnetic lithium ferrite powders with Li:Fe ratios of 1:1, 1:3 and 1:5 have been synthesized, successfully obtaining phase-pure materials (LiFeO2 and LiFe5O8), as well as a controlled mixture of both phases. The powders have been compacted and subsequently sintered by thermal treatment (Tmax = 1100 {\deg}C) to fabricate dense pellets which preserve the original Li:Fe ratios. Li-content on both powders and pellets has been determined by two independent methods: (i) Rutherford backscattering spectroscopy combined with nuclear reaction analysis and (ii) Rietveld analysis of powder X-ray diffraction data. With good agreement between both techniques, it has been confirmed that the Li:Fe ratios employed in the synthesis are maintained in the sintered ceramics. The same conclusion is drawn from spatially-resolved confocal Raman microscopy experiments on regions of a few microns. Field emission scanning electron microscopy has evidenced the substantial grain growth taking place during the sintering process - mean particle sizes rise from about 600 nm in the powders up to 3.8(6) um for dense LiFeO2 and 10(2) um for LiFe5O8 ceramics