519 research outputs found

    Inhibition of LpxC Increases the Activity of Iron Chelators and Gallium Nitrate in Multidrug-Resistant Acinetobacter baumannii

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    Infections caused by multidrug-resistant Acinetobacter baumannii would benefit from the development of novel treatment approaches. Compounds that interfere with bacterial iron metabolism, such as iron chelators and gallium nitrate, have previously been shown to have antimicrobial activity against A. baumannii. In this study, we characterize the effect of LpxC inhibitors on the antimicrobial activity of previously characterized iron chelators, 2,2'-bipyridyl (BIP) and deferiprone (DFP), and gallium nitrate (Ga(NO3)3) against A. baumannii reference strains and multidrug-resistant clinical isolates. The LpxC inhibitor LpxC-2 was synergistic with BIP for 30% of strains tested (FICI values: 0.38-1.02), whereas inhibition with LpxC-4 was synergistic with BIP for 60% of strains tested (FICI values: 0.09-0.75). In time-kill assays, combinations of BIP with both LpxC inhibitors demonstrated synergistic activity, with a more than 3 log10 reduction in bacterial counts compared to BIP alone. LpxC-2 was synergistic with Ga(NO3)3 for 50% of strains tested (FICI values: 0.27-1.0), whereas LpxC-4 was synergistic with Ga(NO3)3 for all strains tested (FICI values: 0.08-≤0.50). In time-kill assays, combinations of Ga(NO3)3 with LpxC-2 and LpxC-4 decreased the growth of both strains compared to each compound separately; however, only the combination with LpxC-4 met the defined criteria for synergy. These results identify a novel synergy between two antimicrobial classes against A. baumannii strains.This research was supported by grants MPY 380/18 from the Instituto de Salud Carlos III (ISCIII) awarded to M.J.M. V.V. is supported by the Río Hortega Program from the Instituto de Salud Carlos III. The APC was funded by MPY 380/18 from the Instituto de Salud Carlos III (ISCIII) awarded to M.J.M.S

    Levels of Physical Activity during School Hours in Children and Adolescents: A Systematic Review

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    Background: This systematic reviewdetermines the levels of physical activity (PA) during school hours in children and adolescents.Methods: Studies carried out fromJanuary 1987 toDecember 2019were retrieved from four databases (Web of Science, Pubmed, Scopus and SportDiscus). Results: Twenty-nine studies were included in this systematic review. Most of them used accelerometers and showed that male and female children accumulated a mean of between 14 and 68 min of moderate-to-vigorous PA (MVPA) during school hours (3–22% of this daily segment), andmale and female adolescents accumulated amean of between 13 and 28min ofMVPA during this daily segment (3–8% of the school hours). Less than a quarter of children and adolescents reached the recommended 30 min of MVPA during school hours, with notable differences between sexes. Conclusions: These results suggest that the levels of PA during school hours are not enough, and consequently, schools should develop strategies for helping children and adolescents reach the school PA recommendation

    Beatriz Galindo : fortuna y poder de una humanista en la corte de los Reyes Católicos

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    La vida y la muerte están unidas en un testamento, a través de este documento –que es un expediente formado por distintos documentos- podemos estudiar la forma de vida y los ingresos de un matrimonio que representa muchos de los aspectos de la Corte de los Reyes Católicos: Francisco Ramírez de Madrid y Beatriz Galindo. Éstos asentaron una parte importante de su fortuna en el Reino de Granada y en la ciudad de Málaga. Este documento también permite conocer cómo la viuda, Beatriz Galindo, pudo apelar a los reyes porque estaba en desacuerdo con la última voluntad de Francisco Ramírez de Madrid.Life and death are linked in a testament, through this document –that is a file of different records- we can study the way of life and the incomes of a couple that represented many aspects of the Court of the Catholic Kings: Francisco Ramírez de Madrid and Beatriz Galindo. They settled an important part of they fortune in the Kingdom of Granada and in the city of Malaga. This record also allows to know how the widow, Beatriz Galindo, could appealed the King and Queen because she was in disagreement with the last wish of Francisco Ramírez de Madrid

    Modelo bidimensional de transmisión de calor en tableros de puente

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    The thermal effects on bridge decks has been a siibject of iilt,erest during the last two decades, beginning the analysis of heat conduction in the deck and the thermal conditions which deal with it. The numerical handling of the problem had been reduced up to the present time, to one-dimensional models of lieat transmission, which can only represent reasonably slab decks, mainly in llie central area. Altliough, tlie most important effects produced by thermal gradients are located in selections with thin walls and in the borders of the deck. The authors have developed a two-dimensional model of lieat conduction that reproduce the temperature field in a complete section of tlie bridge in a realistic manner

    Determinación experimental de la carga de apertura de grieta en fatiga bajo cargas aleatorias

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    El concepto de carga de apertura o cierre de grieta es ampliamente utilizado en fatiga para justificar el comportamiento del crecimiento de grietas con distintas relaciones de carga y el efecto de interacción de las cargas. Hasta la fecha son numerosas las técnicas experimentales propuestas para medir la apertura de grieta y entre ellas los métodos de flexibilidad son ampliamente utilizados por su simplicidad. En este trabajo se propone una modificación del método propuesto por la ASTM y se presentan los resultados obtenidos en ensayos de crecimiento de grietas por fatiga bajo cargas aleatorias. Así mismo, los valores experimentales de cargas de apertura son comparados con los calculados analíticamente por un modelo de simulación tipo “strip-yield” implementado en el software NASGRO. En general, se ha encontrado una concordancia razonablemente buena entre los valores experimentales y los obtenidos por simulación.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Los autores agradecen la financiación aportada para la realización de este trabajo al Ministerio de Economía y Competitividad (referencia MAT2016-76951-C2-2-P)

    Métodos de plano crítico para el análisis de fatiga multiaxial en el acero inoxidable 316

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    El presente trabajo estudia la capacidad de predicción de los modelos de plano crítico para casos de fatiga multiaxial. El material que se estudia es un acero inoxidable 316. Los caminos de carga aplicados son uniaxiales y biaxiales en la superficie de la probeta. El siguiente estudio realiza una comparativa de las predicciones de vida a fatiga y ángulo de grieta de los modelo Wang-Brown, Fatemi-Socie, Liu I y Liu II. Se observó que la mejor predicción de vida fue devuelta por el modelo de Liu II y para el ángulo de grieta por Liu I.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Los autores agradecen la financiación aportada para la realización de este trabajo al Ministerio de Economía y Competitividad (referencia MAT2016-76951-C2-2-P)

    Improvements to the X-ray Spectrometer at the Aerosol Laboratory, Instituto de Física, UNAM

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    Due to the demands of better (accurate and precise) analytical results using X-ray Fluorescence (XRF) at the Aerosol Laboratory, Instituto de Física, UNAM, it was necessary to carry out improvements in instrumentation and analytical procedures in the x-ray spectrometer located in this facility. A new turbomolecular vacuum system was installed, which allows reaching the working pressure in a shorter time. Characteristic x-rays are registered with a Silicon Drift Detector, or SDD, (8 mm thick Be window, 140 eV at 5.9 keV resolution), working directly in a high-vacuum, permitting the detection of x-rays with energies as low as 1 keV (Na Ka) and higher counting rates than in the past. Due to the interference produced by the Rh L x-rays emitted by the tube normally used for atmospheric and food analysis with Cl K x-rays, another tube with a W anode was mounted in the spectrometer to avoid this interference, with the possibility to select operation with any of these tubes. Examples of applications in atmospheric aerosols and other samples are presented, to demonstrate the enhanced function of the spectrometer. Other future modifications are also explained

    Delayed development of basal spikelets in wheat explains their increased floret abortion and rudimentary nature

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    Large differences exist in the number of grains per spikelet across an individual wheat (Triticum aestivum L.) spike. The central spikelets produce the highest number of grains, while apical and basal spikelets are less productive, and the most basal spikelets are commonly only developed in rudimentary form. Basal spikelets are delayed in initiation, yet they continue to develop and produce florets. The precise timing or the cause of their abortion remains largely unknown. Here, we investigated the underlying causes of basal spikelet abortion using shading applications in the field. We found that basal spikelet abortion is likely to be the consequence of complete floret abortion, as both occur concurrently and have the same response to shading treatments. We detected no differences in assimilate availability across the spike. Instead, we show that the reduced developmental age of basal florets pre-anthesis is strongly associated with their increased abortion. Using the developmental age pre-abortion, we were able to predict final grain set per spikelet across the spike, alongside the characteristic gradient in the number of grains from basal to central spikelets. Future efforts to improve spikelet homogeneity across the spike could thus focus on improving basal spikelet establishment and increasing floret development rates pre-abortion
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