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Gasteiz / Vitoria, Spain

Iriarte-Velasco U.,Paseo Of La University | Sierra I.,Paseo Of La University | Cepeda E.A.,Paseo Of La University | Bravo R.,Paseo Of La University | Ayastuy J.L.,University of the Basque Country
Coloration Technology | Year: 2015

Bone is an inorganic template containing organic material inside which can be converted into hydroxyapatite-rich material by pyrolysis. Nowadays, there is a growing research interest in the use of hydroxyapatite, the chemical formula of which is Ca10(PO4)6(OH)2. In the present work, pork bone, an abundant biomass source and food waste, has been converted into structured porous hydroxyapatite by a three-step process including precharring under mild conditions, chemical activation, and thermal activation. The investigated activating agents were NaOH, KOH, K2CO3, H2SO4, and H3PO4. A thorough investigation of the influence of different activating protocols on the chemical and textural properties of the produced material was carried out by nitrogen adsorption-desorption at 77 K, potentiometric titrations, Fourier transform infrared, and X-ray diffraction techniques. Chemical activation with NaOH, K2CO3, and H2SO4 increased the specific surface area up to 53%. H3PO4 reduced both surface area and pore volume, and KOH showed little influence on the pore structure. The produced materials were evaluated by methylene blue adsorption tests and showed significant improvement as a result of chemical activation. As a main effect, acid treatment increased methylene blue adsorption kinetics, probably owing to an increase in micropororosity, whereas alkali activation enhanced the adsorption capacity of the resultant biochar. © 2015 Society of Dyers and Colourists. Source


Alberdi G.,University of the Basque Country | Alberdi G.,CIBER ISCIII | Macarulla M.T.,University of the Basque Country | Macarulla M.T.,CIBER ISCIII | And 5 more authors.
Journal of Physiology and Biochemistry | Year: 2014

Resveratrol (RSV) is known to have an antiobesogenic effect because it mimics energy restriction. However, hardly any evidence exists concerning the combined effects of RSV and energy restriction on body fat reduction. So, the aim of the present study was to determine whether RSV increases body fat reduction induced by energy restriction. Male Wistar rats were fed a high-fat, high-sucrose diet for 6 weeks to obtain a diet-induced obesity model. Then they were submitted to a mild energy restriction (25%) without or with RSV supplementation (30 mg/kg body weight/day) for 2 weeks. Final body weight, subcutaneous and intra-abdominal white adipose tissues weights, Adipose Index, and serum triacylglycerol, cholesterol, glucose, and insulin were assessed. Lipoprotein lipase (LPL), fatty acid synthase (FAS), and acetyl coenzyme A carboxylase (ACC) activities, as well as their genetic expressions, were measured in white adipose tissue. Final body weight, white adipose tissue weights, Adipose Index, and serum triacylglycerol, cholesterol, and insulin were reduced in both groups, but no differences were found among them. FAS, ACC, and LPL activities and expressions were also similar in both groups. These results suggest a lack of any adjuvant effect of RSV on energy restriction for obesity treatment purposes. © University of Navarra 2014. Source


Alberdi G.,University of the Basque Country | Alberdi G.,CIBER ISCIII | Rodriguez V.M.,University of the Basque Country | Rodriguez V.M.,CIBER ISCIII | And 9 more authors.
Food Chemistry | Year: 2013

The effect of resveratrol on thermogenesis in skeletal muscle and interscapular brown adipose tissue (IBAT) was investigated. Rats were fed an obesogenic diet supplemented with resveratrol (30 mg/kg/day) or not supplemented for 6 weeks. Resveratrol intake led to increased gene expression of mitochondrial-transcription-factor-A (TFAM), mitochondrial-protein-cytochrome-C- oxidase subunit-2 (COX2), sirtuin-1 (SIRT1), peroxisome-proliferator-activated- receptor-β/δ (PPARβ/δ) and proliferator-activated- receptor-gamma-coactivator1-α (PGC-1α) in IBAT and increased UCP1 protein expression; however, peroxisome-proliferator-activated-receptor-α (PPARα) expression remained unchanged. In gastrocnemius muscle, resveratrol increased the gene expression of TFAM and COX2; however, no changes were observed in levels of SIRT1, PGC-1α and PPARβ/δ. Acetylated-PGC-1α was decreased in the resveratrol-treated group, indicating a higher level of activation, and a significant increase of UCP3 protein expression was observed in this group. The increases in UCP protein expression in two important thermogenic tissues after resveratrol treatment may contribute to increased whole-body energy dissipation, which may help to better understand the body-fat lowering effect of this polyphenol. © 2013 Elsevier Ltd. All rights reserved. Source


Vivanco M.G.,CIEMAT | Azula O.,Paseo Of La University | Palomino I.,CIEMAT | Martin F.,CIEMAT
Studies in Computational Intelligence | Year: 2011

Modelling has become a very useful tool in air quality management. The accurate prediction of air quality using numerical models involves correctly simulating both the meteorology and chemical processes. Resolution plays an essential role in the quality of model predictions. Choosing an appropriate resolution is important to obtain good air quality forecasts. In this paper the influence of four different model resolutions on model predictions has been analyzed over the Madrid area for a summer period in 2004. The comparison between model results and observations using traditional evaluation statistics for some pollutants indicate that a significant improvement is found when comparing the coarsest domains, but it is much lower or inexistent for the finest domains. A spectral analysis of a topographic profile crossing the area and the evaluation of predicted meteorological parameters, such as wind speed and temperature, suggests that transitioning from 36-to 19-km grid spacing allows the definition of the major mesoscale topographic features and therefore, the atmospheric circulations. A better behaviour of pollutant predictions should be related to an improvement of meteorological predictions in terms of the parameterizations involved in the meteorological model and the input data, such as land use information. Also the use of more accurate emissions is needed to improve the traditional objective verification scores. © 2011 Springer-Verlag Berlin Heidelberg. Source


de Blas M.,University of the Basque Country | Navazo M.,University of the Basque Country | Alonso L.,University of the Basque Country | Durana N.,University of the Basque Country | Iza J.,Paseo Of La University
International Journal of Environmental Analytical Chemistry | Year: 2013

The measurement of halogenated hydrocarbons in the atmosphere is a matter of great interest owing to their adverse effects on the human health and the environment. This work is focused on the measurement of three toxic chlorinated hydrocarbons: trichloroethylene (TCE), tetrachloroethylene (PCE), and carbon tetrachloride (CTC). Moreover, CTC is a greenhouse gas and an ozone depleting gas, restricted under the Montreal Protocol. Owing to their low reactivity, the target chlorinated hydrocarbons are considered to be persistent and, thus, many measurements only address their mean mixing ratios (a concentration measure expressed as mol/mol). Consequently, most of the reported data have low temporal resolution as daily, seasonal or yearly mean mixing ratios, obtained with few measurements. In the study reported in this paper hourly measurements were performed for a long period of time: almost two years for TCE and PCE, and one year for CTC. The main objective was to study the temporal variability of the chlorinated hydrocarbons with high temporal resolution in order to identify their main sources and to enhance the understanding of their atmospheric processes. During the measurement period, March 2007-February 2008 with N = 3290 valid data, CTC showed a mean mixing ratio of 0.16 ppbv (SD = 0.13) with lower temporal variability than the majority of non-methane hydrocarbons (NMHCs), being very well mixed in the urban atmosphere owing to its long lifetime. TCE and PCE mean mixing ratios for the May 2006-February 2008 period, were 0.13 ppbv (SD = 0.42, N = 4601) and 0.25 ppbv (SD = 0.54, N = 4709) respectively, with a larger temporal variability. The study of the sources of TCE and PCE reveals that both compounds have industrial and/or commercial origin, but with different main sources. © 2013 Copyright Taylor and Francis Group, LLC. Source

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