706 research outputs found

    Effect of influenza-induced fever on human bioimpedance values

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    BACKGROUND AND AIMS: Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. METHODS: Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. RESULTS: For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). CONCLUSIONS: There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states

    Magnetically recoverable TiO2-WO3 photocatalyst to oxidize bisphenol A from model wastewater under simulated solar light

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    A novel magnetically recoverable, visible light active TiO2-WO3 composite (Fe3O4@SiO2@TiO2-WO3) was prepared to enable the photocatalyst recovery after the degradation of bisphenol A (BPA) under simulated solar light. For comparison, the photocatalytic activity of other materials such as non-magnetic TiO2-WO3, Fe3O4@SiO2@TiO2, TiO2, and the commercial TiO2 P25 was also evaluated under the studied experimental conditions. The structure and morphology of the synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and electron dispersion spectroscopy (EDS). Moreover, Brunauer-Emmett-Teller (BET) surface area and magnetic properties of the samples were determined. The Fe3O4@SiO2@TiO2-WO3 and TiO2-WO3 led to a BPA degradation of 17.50 and 27.92 %, respectively, after 2 h of the simulated solar light irradiation. Even though their activity was lower than that of P25, which degraded completely BPA after 1 h, our catalysts were magnetically separable for their further reuse in the treatment. Furthermore, the influence of the water matrix in the photocatalytic activity of the samples was studied in municipal wastewater. Finally, the identification of reaction intermediates was performed and a possible BPA degradation pathway was proposed to provide a better understanding of the degradation process

    FTIR-ATR Spectroscopy Combined with Multivariate Regression Modeling as a Preliminary Approach for Carotenoids Determination in Cucurbita spp

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    Quantitative analysis of carotenoids has been extensively reported using UV\u2010Vis spectrophotometry and chromatography, instrumental techniques that require complex extraction protocols with organic solvents. Fourier transform infrared spectroscopy (FTIR) is a potential alternative for simplifying the analysis of food constituents. In this work, the application of FTIR with attenuated total reflectance (ATR) was evaluated for the determination of total carotenoid content (TCC) in Cucurbita spp. samples. Sixty\u2010three samples, belonging to different cultivars of butternut squash (C. moschata) and pumpkin (C. maxima), were selected and analyzed with FTIR\u2010 ATR (attenuated total reflectance). Three different preparation protocols for samples were followed: homogenization (A), freeze\u2010drying (B), and solvent extraction (C). The recorded spectra were used to develop regression models by Partial Least Squares (PLS), using data from TCC, determined by UV\u2010Vis spectrophotometry. The PLS regression model obtained with the FTIR data from the freeze\u2010dried samples, using the spectral range 920\u20133000 cm 121, had the best figures of merit (R2CAL of 0.95, R2PRED of 0.93 and RPD of 3.78), being reliable for future application in agriculture. This approach for carotenoid determination in pumpkin and squash avoids the use of organic solvents. Moreover, these results are a rationale for further exploring this technique for the assessment of specific carotenoids in food matrices

    Light elements in stars with exoplanets

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    Light elements are important tracers of the internal stellar structure and kinematics. Li and Be are both burned in the stellar interiors but Be requires much higher temperatures and thus we can expect to measure Be abundances in stars which have no detectable Li in their atmospheres. The study of these elements can give us information about processes related to the angular momentum history of these stars, since rotation and angular momentum loss are important mechanisms responsible for the depletion of light elements. Additionally, if pollution has played an important role in determining the high-metal content of planet host stars, we would expect to find a similar or even higher increase in the Li and Be contents. We present Be and Li abundances in a sample of 69 stars with planets and 31 stars without known planetary companion, spanning a large range of effective temperature

    Studying the electronic and charge transport properties of two cyclocarbazole derivates

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    Molecular systems have proven to be efficient active materials in electronics, being possible alternatives to the inorganic semiconductors used nowadays in electronic devices. For this reason, organic electronics has emerged as a research field with great potential and interest. In this project, an experimental and theoretical study of two carbazole-based macrocycles is presented (Figure 1). Specifically, we investigated the impact of the inclusion of acetylene groups on the electronic and molecular structures of these macrocycles, as well as their potential as charge transporting materials. The first studied compound (Cz) is composed by four carbazole groups linked at their para position with respect to the nitrogen atom[1]. In the second compound (ACz), the carbazole units are connected through ethynylene groups[2]. For this study, Raman and UV-Vis absorption spectroscopies have been used in combination with theoretical calculations based on the density functional theory (DFT). In addition, the two studied compounds have been implemented in organic field-effect transistors (OFETs), to assess their potential as active materials in organic electronics. Overall, the inclusion of ethynylene groups as π-conjugated spacers is found to be a good strategy to improve the electronic delocalization in macrocycles.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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