727 research outputs found

    Exploring the dynamics of finite-energy Airy beams: A trajectory analysis perspective

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    In practice, Airy beams can only be reproduced in an approximate manner, with a limited spatial extension and hence a finite energy content. To this end, different procedures have been reported in the literature, based on a convenient tuning of the transmission properties of aperture functions. In order to investigate the effects generated by the truncation and hence the propagation properties displayed by the designed beams, here we resort to a new perspective based on a trajectory methodology, complementary to the density plots more commonly used to study the intensity distribution propagation. We consider three different aperture functions, which are convoluted with an ideal Airy beam. As it is shown, the corresponding trajectories reveals a deeper physical insight about the propagation dynamics exhibited by the beams analyzed due to their direct connection with the local phase variations undergone by the beams, which is in contrast with the global information provided by the usual standard tools. Furthermore, we introduce a new parameter, namely, the escape rate, which allow us to perform piecewise analyses of the intensity distribution without producing any change on it, e.g., determining unambiguously how much energy flux contributes to the leading maximum at each stage of the propagation, or for how long self-accelerating transverse propagation survives. The analysis presented in this work thus provides an insight into the behavior of finite-energy Airy beams, and therefore is expected to contribute to the design and applications exploiting this singular type of beams.Comment: 14 pages, 5 figure

    Synovial inflammation in an experimental model of metabolic syndrome in the rabbit

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    Objetivo: Analizar el efecto del síndrome metabólico (SM) sobre la inflamación sinovial en un modelo experimental en conejo. Material y métodos: Se probaron tres intervenciones dietéticas diferentes para inducir un modelo experimental de SM, en 21 conejos New Zealand hembra, de 8 meses de edad: 1) alimentación con dieta enriquecida con 1% de colesterol y 3% de aceite de cacahuete y agua ad libitum; 2) alimentación con dieta normal y agua con 30% de fructosa ad libitum; 3) alimentación con dieta enriquecida con 1% de colesterol y 3% de aceite de cacahuete y agua con 30% de fructosa ad limitum. Los animales se dejaron evolucionar durante 12 semanas y se hizo un seguimiento semanal de peso, glucosa basal, colesterol HDL, triglicéridos. Tras el sacrificio, se tomaron muestras de membrana sinovial para cuantificar el infiltrado macrofágico sinovial mediante inmunohistoquímica. Resultados: La única intervención dietética con la que conseguimos inducir alteraciones asociadas al SM en los conejos fue alimentándolos con una dieta hiperlipémica. Estos animales, además de presentar hiperglucemia y dislipemia, tenían un infiltrado macrofágico sinovial mayor que el del grupo control. Conclusión: La alimentación con dieta hiperlipémica induce alteraciones típicas del SM en el conejo, acompañadas de un aumento del infiltrado macrofágico sinovial, lo que sugiere que el macrófago podría desempeñar un papel importante en el inicio y/o la progresión de la artrosis descrita que se asocia con el SMObjetive: To analyze the effect of metabolic syndrome (MS) upon synovial inflammation in an experimental model in the rabbit. Material and methodology: Three different diets were used to induce an experimental model of MS in 21 female New Zealand rabbits (aged 8 months): 1) diet enriched with 1% cholesterol and 3% peanut oil, with water, ad libitum; 2) normal diet, with water, and 30% fructose, ad libitum; 3) diet enriched with 1% cholesterol and 3% peanut oil, with water, and 30% fructose, ad libitum. The animals were followed-up on for 12 weeks, with weekly monitoring of body weight, basal glucose, HDL-cholesterol and triglycerides. Following sacrifice, synovial membrane samples were collected to quantify the synovial macrophage infiltrate using immunohistochemical techniques. Results: The only diet to induce alterations associated with MS in the rabbits was the hyperlipidemic diet. These animals, in addition to presenting hyperglycemia and dyslipidemia, showed greater synovial macrophage infiltration than the control group. Conclusion: A hyperlipidemic diet induces alterations typical of MS in the rabbit, accompanied by an increase in synovial macrophage infiltrationEsta investigación ha sido financiada por FUNDACIÓN MAPFR

    Mechanical and optical properties of ultralarge flakes of a metal-organic framework with molecular thickness

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    The isolation of 2D-materials is already a success for graphene, graphene oxide, boron nitride and a few clays or metal chalcogenides, however despite the fact that some of them show very interesting physical properties, they lack useful functionalities. Metal-Organic Frameworks (MOFs) are multifunctional materials showing a wide range of physical and chemical properties that can be structurally designed by suitable selection of their building-blocks. This strategy may allow the production of layers with a variety of useful electronic and molecular recognition functionalities. Herein we isolate 2D-MOF flakes with areas of hundreds of square microns and an excellent control of the molecular thickness (from single up to ca. 50 layers). The samples exhibit such good photoluminescence and mechanical properties as to allow free-standing characterization of few layers' flakesThe authors acknowledge financial support from MICINN (MAT2013-46753-C2-1-P and MAT2013-46753-C2-2-P and Consolider CSD2010-00024

    Combining microfluidic paper-based platform and metal–organic frameworks in a single device for phenolic content assessment in fruits

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    A microfluidic paper-based device (µPAD) has been combined with metal–organic frameworks (MOFs) for total phenolic compounds (TPC) quantification in fruit samples for the first time. The performance of the µPAD, based upon the vertical flow approach, was enhanced in order to determine the TPC content with high accuracy in fruit samples. The method was based on the traditional Folin-Ciocalteu Index using gallic acid or oenotannin as reference phenolic compounds. This novel design and construction of the device are in agreement with the principles of Green Chemistry avoiding wax technology (lower toxicity). The analytical parameters that affect the colorimetric method (using digital imaging of the colored zone) performance were optimized including design, sample volume, and MOF amount. Then, the analytical features of the developed method were investigated such as dynamic range (1.6–30 mg L−1), limit of detection (0.5 mg L−1), and precision (RSD < 9%). Besides, the in-field analysis is achievable with a color stability up to 6 h after the loading process of the sample and storage stability for at least 15 days without performance losses (under vacuum at − 20 °C). Furthermore, the MOF ZIF-8@paper was characterized to study its composition and the successful combination. The feasibility of the proposed method was demonstrated by determining the TPC in 5 fruit samples using oenotannin as reference solute. The accuracy was validated by comparison of the data with the results obtained with the recommended protocol proposed by the International Organisation of Vine and Wine (OIV).info:eu-repo/semantics/publishedVersio

    Effect of soiling in CPV systems

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    The effect of soiling in flat PV modules has been already studied, causing a reduction of the electrical output of 4% on average. For CPV's, as far as soiling produces light scattering at the optical collector surface, the scattered rays should be definitively lost because they cannot be focused onto the receivers again. While the theoretical study becomes difficult because soiling is variable at different sites, it becomes easier to begin the monitoring of the real field performance of concentrators and then raise the following question: how much does the soiling affect to PV concentrators in comparison with flat panels?? The answers allow to predict the PV concentrator electrical performance and to establish a pattern of cleaning frequency. Some experiments have been conducted at the IES-UPM and CSES-ANU sites, consisting in linear reflective concentration systems, a point focus refractive concentrator and a flat module. All the systems have been measured when soiled and then after cleaning, achieving different increases of ISC. In general, results show that CPV systems are more sensitive to soiling than flat panels, accumulating losses in ISC of about 14% on average in three different tests conducted at IESUPM and CSES-ANU test sites in Madrid (Spain) and Canberra (Australia). Some concentrators can reach losses up to 26% when the system is soiled for 4 months of exposure

    The impact of a web-based lifestyle educational program (‘Living Better’) Reintervention on hypertensive overweight or obese patients

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    ‘Living Better’, a self-administered web-based intervention, designed to facilitate lifestyle changes, has already shown positive short-and medium-term health benefits in patients with an obesity–hypertension phenotype. The objectives of this study were: (1) to examine the long-term (3-year) evolution of a group of hypertensive overweight or obese patients who had already followed the ‘Living Better’ program; (2) to analyze the effects of completing this program a second time (reintervention) during the COVID-19 pandemic. A quasi-experimental design was used. We recruited 29 individuals from the 105 who had participated in our first study. We assessed and compared their systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI), eating behavior, and physical activity (PA) level (reported as METs-min/week), at Time 0 (first intervention follow-up), Time 1 (before the reintervention), and Time 2 (post-reintervention). Our results showed significant improvements between Time 1 and Time 2 in SBP (-4.7 (-8.7 to -0.7); p = 0.017), DBP (-3.5 (-6.2 to -0.8); p = 0.009), BMI (-0.7 (-1.0 to -0.4); p 0.24). Implementation of the ‘Living Better’ program maintained positive long-term (3-year) health benefits in patients with an obesity–hypertension phenotype. Moreover, a reintervention with this program during the COVID-19 pandemic produced significant improvements in blood pressure, BMI, eating behavior, and PA. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    Advances in bimodal AFM imaging of molecules in Liquid

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    Conferencia invitada presentada en la 14th International Conference on Noncontact AFM, celebrada en Lindau (Alemania).Improving spatial resolution, data acquisition times and material properties imaging are some long established goals in atomic force microscopy (AFM). Currently, the most promising approaches to reach those goals involve the excitation and detection of several frequencies of the tip’s oscillation. Usually those frequencies are associated with either the higher harmonics of the oscillation or the eigenmodes of the cantilever. Bimodal AFM is an emerging multifrequency technique that is characterized by a high signal-to-noise ratio and the versatility to measure simultaneously different forces. The method is also compatible with molecular resolution imaging under the application of sub-50 pN peak forces.Peer Reviewe

    Regulatory effects of miR-19a on MAD2 expression and tumorigenesis in gastric cancer

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    Gastric cancer (GC) is worldwide the sixth most diagnosed and third leading cause of cancer deaths, with poor and late prognosis, probably due to post-surgery adjuvant treatment resistance and lack of a thorough panel of prognostic markers. We have previously shown that mitotic arrest deficient 2 (MAD2, encoded by MAD2L1), a key protein of the spindle assembly checkpoint, is relevant in GC cells; its interference impairs migration and growth, while its overexpression correlates with tumorigenesi

    Thioredoxin Domain Containing 5 Suppression Elicits Serum Amyloid A-Containing High-Density Lipoproteins

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    Thioredoxin domain containing 5 (TXNDC5) is a protein disulfide isomerase involved in several diseases related to oxidative stress, energy metabolism and cellular inflammation. In a previous manuscript, a negative association between fatty liver development and hepatic Txndc5 expression was observed. To study the role of TXNDC5 in the liver, we generated Txndc5-deficient mice. The absence of the protein caused an increased metabolic need to gain weight along with a bigger and fatter liver. RNAseq was performed to elucidate the putative mechanisms, showing a substantial liver overexpression of serum amyloid genes (Saa1, Saa2) with no changes in hepatic protein, but discrete plasma augmentation by the gene inactivation. Higher levels of malonyldialdehyde, apolipoprotein A1 and platelet activating factor-aryl esterase activity were also found in serum from Txndc5-deficient mice. However, no difference in the distribution of high-density lipoproteins (HDL)-mayor components and SAA was found between groups, and even the reactive oxygen species decreased in HDL coming from Txndc5-deficient mice. These results confirm the relation of this gene with hepatic steatosis and with a fasting metabolic derive remedying an acute phase response. Likewise, they pose a new role in modulating the nature of HDL particles, and SAA-containing HDL particles are not particularly oxidized. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
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