571 research outputs found

    Metallic slabs: Perturbative treatments based on jellium

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    We examine first-order perturbative results based on jellium for the surface energy of slabs of simple metals, using various local pseudopotentials (Ashcroft, Heine-Abarenkov and evanescent core). The difference between the pseudopotential and the jellium potential is averaged along the plane parallel to the surface. We compare these perturbative results with those of the stabilized jellium model (a modification of the regular jellium model in which the perturbation appears in the energy functional right from the outset) and with the output of other perturbative and non-perturbative calculations.Comment: 15 pages, 2 figures, to appear in Prog. Surf. Sc

    Gold(I) Carbenoids: On-Demand Access to Gold(I) Carbenes in Solution

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    Chloromethylgold(I) complexes of phosphine, phosphite, and N-heterocyclic carbene ligands are easily synthesized by reaction of trimethylsilyldiazomethane with the corresponding gold chloride precursors. Activation of these gold(I) carbenoids with a variety of chloride scavengers promotes reactivity typical of metallocarbenes in solution, namely homocoupling to ethylene, olefin cyclopropanation, and Buchner ring expansion of benzene

    New approach to managing COVID-19 pandemic in a complex tertiary care medical centre in Madrid, Spain

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    The COVID-19 pandemic is putting healthcare systems under unprecedented stress to accommodate unexpected numbers of patients forcing a quick re-organization. This article describes the staff management experience of a third level referral hospital in the city of Madrid, Spain, one of the cities and hospitals with the largest number of COVID19 cases. A newly created COVID-19-specific Clinical Management Unit (CMU) coordinated all clinical departments and conducted real-time assessments of the availability and needs of medical staff, alongside the hospital's general management board. The Unit was able to (i) redeploy up to 285 physicians every week to bolster medical care in COVID-19 wards and forecast medical staff requirements for the upcoming week so all departments could organize their work while coping with COVID-19 needs, (ii) overview all clinical activities conducted in a medicalized hotel, and (iii) recruit a team of roughly 90 volunteer medical students to accelerate data collection and evidence generation. The main advantage of a clinical management unit composed by a member of every job category - its ability to generate rapid, locally-adapted responses to unexpected challenges - made it perfect for the unprecedented increase in healthcare need generated by the COVID-19 pandemic

    Bioconversion of polyphenols and organic acids by gut microbiota of predigested Hibiscus sabdariffa L. calyces and Agave (A. tequilana Weber) fructans assessed in a dynamic in vitro model (TIM-2) of the human colon

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    The present work aimed at understanding gut microbiota bioconversion of phenolic compounds (PC) and organic acids in predigested Hibiscus sabdariffa (Hb) calyces and the mixture of Hb and Agave (Agave tequilana Weber) fructans (AF). With this purpose, dried Hb and Hb/AF were predigested with enzymatic treatment, and then fermented in a dynamic in vitro model of the human colon (TIM-2). After HPLC-ESI-QToF-MS analysis of samples taken at 0, 24, 48 and 72 h of fermentation, it was observed that hydroxycinnamic acids, flavanols, flavonols, and anthocyanins were mainly transformed into derivatives of hydroxyphenylpropionic, hydroxyphenylacetic and hydroxybenzoic acids. Moreover, organic acids, such as hydroxycitric and hibiscus acids, were formed along with unidentified lactones and reduced compounds. Interestingly, no differences were observed between microbial-derived metabolites formed after the fermentation of Hb and Hb/AF. In conclusion, colonic fermentation of polyphenol-rich Hb yields a wide range of microbial phenolic metabolites with potential effects on health.RMB and SGSA acknowledge to Science and Technology for Development Program (CYTED) through the Ibero-American Network of Underutilized Autonomous Foods (ALSUB-CYTED, 118RT0543). SGSA acknowledges CONACYT-Mexico for the sabbatical grant 260935. The Spanish Ministry of Science, Innovation and Universities (Project AGL2015-69986-R) is also acknowledged. This research has been made possible with the support of the Dutch Province of Limburg.Peer reviewe

    Quality of care assessment for people with multimorbidity.

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    Multimorbidity, the simultaneous presence of multiple health conditions in an individual, is an increasingly common phenomenon globally. The systematic assessment of the quality of care delivered to people with multimorbidity will be key to informing the organization of services for meeting their complex needs. Yet, current assessments tend to focus on single conditions and do not capture the complex processes that are required for providing care for people with multimorbidity. We conducted a scoping review on quality of care and multimorbidity in selected databases in June 2018 and identified 87 documents as eligible for review, predominantly original research and reviews from North America, Europe and Australasia and mostly frequently related to primary care settings. We synthesized data qualitatively in terms of perceived challenges, evidence and proposed metrics. Findings reveal that the association between quality of care and multimorbidity is complex and depends on the conditions involved (quality appears to be higher for those with concordant conditions, and lower in the presence of discordant conditions) and the approach used for measuring quality (quality appears to be higher in people with multimorbidity when measured using condition/drug-specific process or intermediate outcome indicators, and worse when using patient-centred reports of experiences of care). People with discordant multimorbidity may be disadvantaged by current approaches to quality assessment, particularly when they are linked to financial incentives. A better understanding of models of care that best meet the needs of this group is needed for developing appropriate quality assessment frameworks. Capturing patient preferences and values and incorporate patients' voices in the form of patient-reported experiences and outcomes of care will be critical towards the achievement of high-performing health systems that are responsive to the needs of people with multimorbidity

    Estimación de las relaciones genéticas entre razas caprinas españolas y criollas utilizando microsatélites

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    We have analyzed three Creole goat populations from Peru, Mexico and Chile using microsatellite markers. We have also analyzed the genetic relationship between them and Murciano-Granadina and Malagueña Spanish goat breeds. The average number of alleles per locus was similar in all populations (7.3) except the Chilean Creole (5.1). This Creole goat population has presented the lowest value of observed (Ho) (0.53) and expected (He) heterozygosis (0.59). The Peruvian Creole has presented the highest values of Ho (0.70) and He (0.71). We have found a scarce level of genetic differentiation between goat populations (FST= 0.069) being more important the individual genetic differences due to crossbreed with several breeds. The Peruvian Creole was closed to analyzed Spanish breeds, followed by Mexican Creole. Finally the Chilean Creole was the most distant to the others populations

    Classification of Landsat 8 images in the Segura Hydrographic Demarcation

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    [EN] This work presents a cartography of land uses in the Segura Hydrographic Demarcation obtained by classifying 2017 Landsat 8 images. The classification was carried out using two classifiers: Maximum Likelihood (ML) and Random Forest (RF). Training areas were obtained from historical high resolution imagery until 2016. Prior to classification, a cross validation analysis of the training areas was carried out to determine which of them may have undergone a change of use between 2016 and 2017. The results obtained with ML and RF, both with the original set of training areas and with the one obtained eliminating the problem, are compared to determine the best option. In the case of ML, the results improve after eliminating the changing training areas, from 77.7% to 81.4%; however, with RF this improvement is not so important, going from 84.1% to 85.1%. Therefore, it can be concluded that, with both methods, the classification is more exact when the modified training areas are used and, although the results obtained are quite acceptable for both ML and RF, the latter performs a more accurate classification.[ES] En el presente trabajo se obtiene, a través de un proceso de clasificación digital de imágenes Landsat 8 de 2017, una cartografía de usos del suelo en la Demarcación Hidrográfica del Segura; la clasificación se ha llevado a cabo empleando dos clasificadores: Máxima Verosimilitud (MV) y Random Forest (RF). Puesto que las áreas de entrenamiento se obtienen de imágenes históricas de alta resolución hasta 2016, previamente a la clasificación, se hace un análisis de validación cruzada de las áreas de entrenamiento para determinar cuáles de ellas pueden haber sufrido un cambio de uso entre 2016 y 2017. Los resultados obtenidos con MV y con RF, tanto con el conjunto original de áreas como con el obtenido eliminando la problemática, se comparan para determinar cuál es la mejor opción. En el caso de MV mejoran notablemente los resultados cuando se realiza la depuración de las áreas de entrenamiento, pasando de un porcentaje de acierto del 81% al 84,9%; sin embargo, con RF esta mejora no es tan importante ya que se pasa del 84,1% al 85,1%. Por tanto, se puede concluir que, con ambos métodos la clasificación es más exacta cuando se emplean las áreas de entrenamiento depuradas y, aunque los resultados obtenidos son bastante aceptables tanto para MV como para RF, este último realiza una clasificación más exacta.Rodríguez-Valero, MI.; Alonso-Sarria, F. (2019). Classification of Landsat 8 images in the Segura Hydrographic DemarcationClasificación de imágenes Landsat-8 en la Demarcación Hidrográfica del Segura. Revista de Teledetección. (53):33-44. https://doi.org/10.4995/raet.2019.11016SWORD33445

    Identification of a non-host semiochemical from miniature pinscher, Canis lupus familiaris, that repels Rhipicephalus sanguineus sensu lato (Acari: Ixodidae)

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    It is already known that the beagle breed of domestic dogs produces semiochemicals capable of repelling the brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.). With a view to discovering new non-host semiochemicals as tick repellents, we compared the semiochemicals produced by a putative tick-resistant breed of dog, miniature pinscher, with known tick-resistant (beagle) and tick-susceptible (English cocker spaniel) breeds. Two non-host compounds produced by beagles, i.e. 2-hexanone and benzaldehyde, were shown to be present in volatile samples collected from all three breeds. Furthermore, two compounds, 6-methyl-5-hepten-2-one and 1,2,4-trimethylbenzene, were found in higher amounts in volatile samples collected from miniature pinscher dogs. The mean amounts of benzaldehyde, 2- hexanone and 1,2,4-trimethylbenzene were similar for beagles and miniature pinschers and higher than the means observed for cocker spaniels, whereas the mean amount of 6-methyl-5-hepten-2-one produced by miniature pinschers was significantly higher than for the other breeds of dogs. In Petri-dish assays with adult R. sanguineus, 6-methyl-5- hepten-2-one was repellent for all observation periods evaluated for the two highest concentrations (0.100 and 0.200 mg.cm-2). Our results support our hypothesis that miniature pinschers are a tick-resistant dog breed and agree with previous observations of miniature pinschers being the breed least parasitized by ticks. Furthermore, the non-host semiochemical 6-methyl-5-hepten-2-one has potential to be developed for use as a repellent for the protection of susceptible dogs from R. sanguineus s.l. ticks
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