18 research outputs found

    Comprehensive Assessment and Potential Ecological Risk of Trace Element Pollution (As, Ni, Co and Cr) in Aquatic Environmental Samples from an Industrialized Area

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    A global assessment of arsenic (As), nickel (Ni), cobalt (Co) and chromium (Cr) was performed in environmental samples from an important industrial bay. Different fractions of water, sediments and tissues from four species of fish were analysed. Samples were collected from selected sampling sites during four consecutive samplings in spring and autumn seasons, in order to evaluate concentrations and their possible correlations among the aquatic compartments. While a higher availability of Cr and Ni was found in water, Co and As were the most available elements in sediments. In fish, the liver was the tissue with the highest proportion of As and Co, and gills showed the highest concentrations of Ni and Cr. Significance differences were observed among sites showing the pollution sources. In sediments, high correlations were found between total Co content and the most available fractions. Total Ni content highly correlated with the oxidisable fraction, while Cr total content tightly correlated with the least available fractions. Quality guideline values for sediments were frequently exceeded. In sediments and biota, concentrations were slightly higher than in other ecosystems, indicating that maritime, industrial and urban activities are affecting this type of ecosystem with great anthropogenic influence.This research was funded by "Consejeria de Economia, Conocimiento, Empresas y Universidad", Junta de Andalucia (Spain) (PAI-EXCEL-06-FQM-02075) and by "Fomento e Impulso de la Investigacion y de la Transferencia" Programme, Universidad de Cadiz (Spain) (PR2020-013)

    Sherry wine industry by-product as potential biosorbent for the removal of Cr(VI) from aqueous medium

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    A low-cost biosorbent obtained from the Palomino Fino grape seed, a Sherry wine industry by-product, has been proposed as a way of valorising this material. The biomass was characterised obtaining values of 0.68 +/- 0.05 g mL(-1) for bulk density, 1.02 +/- 0.09 g mL(-1) for apparent density and 33.3% for porosity. The pH(pzc) was 5.2 and the surface negative charge value was 2.4 +/- 0.2 mmol g(-1). The analysis of surface morphology showed differences due to the sorption. The results showed a promising potential for chromium(VI) removal from aqueous solutions. The studies were carried out in batch scale and a 2(3) factorial design was applied for the optimisation of the process. A percentage of 91.7 +/- 0.6% was achieved for the biosorption of Cr(VI) under optimal conditions using pH 5.5, 15 g/L of biosorbent and 8 h of contact time. The biosorption capacity showed a remarkable linearity from 0 to 2 mmol L-1 Cr(VI) and a precision of 0.64% for the removal of 1 mmol L-1 of metal. Langmuir, Freundlich and Temkin isotherm equations and the parameters of six kinetic models were used in the equilibrium modelling and identifying the mechanism of the biosorption. The combination of physical and chemical sorption mechanisms was proposed for the chromium removal with a high maximum sorption capacity (q(max) = 208.3 mg g(-1)). Thermodynamic parameters indicated the spontaneous and endothermic nature of the chromium removal. The successful biosorption was based on the special grape seed components with a relevant content in antioxidant and lignocellulosic compounds.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has been supported by "Consejeria de Economia, Conocimiento, Empresas y Universidad", Andalusian Government (Spain) (support for RNM-236 Research group) and the Programme of "Fomento e Impulso de la Investigacion y de la Transferencia" from the University of Cadiz (Spain) (Project PR2020-013)

    Sensing Cd(II) Using a Disposable Optical Sensor Based on a Schiff Base Immobilisation on a Polymer-Inclusion Membrane. Applications in Water and Art Paint Samples

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    A disposable colour-changeable optical sensor based on an interesting polymer inclusion-membrane (PIM) was designed to determine Cd(II) ions in aqueous medium. The Schiff base 2-acetylpyridine benzoylhydrazone (2-APBH) immobilised on the polymer membrane was used as a sensing molecule. The amounts of the PIM components were optimised by a 3(2) fractional factorial design with two central points and two blocks. The best optical sensor composition consisted of 2.5 g of poly(vinylchloride) (PVC) as a base polymer, 3 mL of tributyl phosphate (TBP) as a plasticiser, and 0.02 g of 2-APBH as a reagent. The sensor showed a good linear response in the range from 0.02 mg L-1 (limit of detection) to 1 mg L-1 of Cd(II) under the following experimental conditions: pH 9.5 (adjusted using ammonium chloride buffer solution at 0.337 mol L-1), 60 min of exposure time plus 2 min of sonication (pulses at 2 s intervals), and 10 min of short-term stability. The relative standard deviation of the method was determined to be 4.04% for 0.4 mg L-1 of Cd(II). The optical sensor was successfully applied to the determination of Cd(II) in natural-water and art-paint samples

    Comparative Baseline Levels of Heavy Metals and Histopathological Notes in Fish From two Coastal Ecosystems of South-West of Spain

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    This work reports the comparative study of heavy metal water concentrations from two coastal ecosystems of Cadiz Gulf (SWSpain): Bay of Cadiz and Ria ofHuelva estuary in samples taken on years 1999-2000. Sampling zones showed different heavymetal levels. Statistical analysis of dissolved trace metal concentrations (Cu, Zn, Cd and Pb) showed significant differences between Huelva and Cadiz zones based on the Cu level, with a marked seasonal factor and different metal sources (Industrial, geological, urban,...), observing a higher Cu concentration in Ria de Huelva respect to Bay of Cadiz. On the other hand, to evaluate the pollutant effects on aquatic biota, a histopathological analysis have been conducted in specimens of flat fish, Solea senegalensis from both zones. Lesions weremore severe in fish fromRia ofHuelva, being themost significant alterations: gill hyperplasia, fusion of secondary lamellae, disorganization of the hepatic parenchyma, cellular hypertrophy and vascular congestion in liver and tubular occlusion, loss of interstitial tissue and lipid-like vacuoles in kidney. Obtained results are useful as reference data for future environmental monitoring studies in these zones where to establish a heavy metal concentration temporal trend would be necessary

    Cámara e imágenes

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    Presentación de diapositivas donde se explica la aplicación de cámara e imágenesUniversidad Nacional, Costa RicaInstituto de Estudios Sociales en PoblaciónEscuela de InformáticaEscuela de Psicologí

    Induction of Oxidative Stress by Waterborne Copper and Arsenic in Larvae of European Seabass (<i>Dicentrarchus labrax</i> L.): A Comparison with Their Effects as Nanoparticles

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    The aim of this work was to compare the potential induction of oxidative stress and the antioxidant enzymatic response after a short-term waterborne exposure to copper (Cu) and arsenic (As) with that of the nanoparticles (NPs) of these elements (Cu-NPs and As-NPs) in fish larvae of the species Dicentrarchus labrax. Larvae were grouped in several tanks and exposed to different concentrations of contaminants (0 to 10 mg/L) for 24 or 96 h under laboratory conditions. Copper and arsenic concentrations were analysed in larval tissues using ICP-MS. A set of oxidative stress biomarkers, including the levels of hydroperoxides (HPs), and superoxide dismutase (SOD) and catalase (CAT) activities were assessed. The trace element concentrations (mg/kg d.w.) in larvae ranged as follows: 3.28–6.67 (Cu at 24 h) and 2.76–3.42 (Cu at 96 h); 3.03–8.31 (Cu-NPs at 24 h) and 2.50–4.86 (Cu-NPs at 96 h); 1.92–3.45 (As at 24 h) and 2.22–4.71 (As at 96 h); and 2.19–8.56 (As-NPs at 24 h) and 1.75–9.90 (As-NPs at 96 h). In Cu tests, the oxidative damage (ROOH levels) was induced from 0.1 mg/L at both exposure times, while for Cu-NPs, this damage was not observed until 1 mg/L, which was paralleled by concomitant increases in SOD activity. The CAT activity was also increased but at lower metal concentrations (0.01 mg/L and 0.1 mg/L for both chemical forms). No oxidative damage was observed for As or As-NPs after 24 h, but it was observed for As after 96 h of treatment with 0.01 mg/L. A decrease in SOD activity was observed for As after 24 h, but it turned out to be increased after 96 h. However, As-NPs did not alter SOD activity. The CAT activity was stimulated only at 96 h by As and at 24 h by As-NPs. Therefore, the two chemical forms of Cu exhibited a higher bioaccumulation and toxicity potential as compared to those of As. Importantly, the association of both Cu and As in NPs reduced the respective trace metal bioaccumulation, resulting also in a reduction in the toxic effects (mortality and biochemical). Furthermore, the assessment of oxidative stress-related biomarkers in seabass larvae appears to be a useful tool for biomonitoring environmental-occurring trace elements

    On generating fuzzy Pareto solutions in fully fuzzy multiobjective linear programming via a compromise method

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    We evaluated the potential use of agri-food waste for the removal of heavy metal ions from aqueous solutions and its application in different processes (e.g., water remediation, in the production of biomass enriched in nutritionally significant elements, etc.). Biomasses from grape seed, grape pomace, loquat seed, Calabrese broccoli stem, empty pods of carob and broad bean pods, unripe bitter orange peel, kumquat, orange pulp and Canary Island banana pulp were prepared. The percentages and biosorption capacities were evaluated and compared with those refe-renced using Valencia orange peel (Citrus sinensis Valencia late). These studies allow for easily providing added value to different agri-food wastes. The results show that the proposed biomasses were able to retain the studied metal ions and obtained different percentages, being in some cases above 90%. The highest values were obtained using broad bean pod (Pb(II) (91.5%), Cd(II) (61.7%), Co(II) (40.7%) and Ni(II) (39.7%)). Similar values were observed using grape seed, broccoli stem, carob pod and unripe bitter orange peel. Carob pod for biosorption of Cd(II) is also of great interest. These studies suggest that the agri-food residues evaluated can be applied to prepare effective biosorbents of divalent metal ions from aqueous solutions

    Ciencias Around You (4ª edición)

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    http://ciencias.uca.es/divulgacion/ies/CAYCiencias Around You es un programa de divulgación científica dirigido preferentemente a alumnos de 4º ESO y 1º de Bachillerato Científico-Tecnológico o Ciencias de la Salud. Los alumnos visitan la Facultad de Ciencias de la Universidad de Cádiz y participan en los talleres “Experimenta en el Laboratorio”, dónde a través de una serie de experimentos pueden descubrir la Biotecnología, Enología, Ingeniería Química y Química, así como a través de una serie de problemas lógicos de Matemáticas esperamos despertar su curiosidad por la Ciencia haciéndoles partícipes por un día, de la vida universitariaDecanato Facultad de Ciencias, Vicerrectorado de Alumnos de la Universidad de Cádi

    Very-high-frequency oscillations in the main peak of a magnetar giant flare

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    Full list of authors: Castro-Tirado, A. J.; Østgaard, N.; Göǧüş, E.; Sánchez-Gil, C.; Pascual-Granado, J.; Reglero, V.; Mezentsev, A.; Gabler, M.; Marisaldi, M.; Neubert, T.; Budtz-Jørgensen, C.; Lindanger, A. Sarria, D.; Kuvvetli, I.; Cerdá-Durán, P.; Navarro-González, J.; Font, J. A.; Zhang, B. -B.; Lund, N.; Oxborrow, C. A.; Brandt, S.; Caballero-García, M. D.; Carrasco-García, I. M.; Castellón, A.; Castro Tirado, M. A.; Christiansen, F.; Eyles, C. J.; Fernández-García, E.; Genov, G.; Guziy, S.; Hu, Y. -D.; Nicuesa Guelbenzu, A.; Pandey, S. B.; Peng, Z. -K.; Pérez del Pulgar, C.; Reina Terol, A. J.; Rodríguez, E.; Sánchez-Ramírez, R.; Sun, T.; Ullaland, K.; Yang, S.Magnetars are strongly magnetized, isolated neutron stars1–3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031–1036 ergs per second and rotation periods of about 0.3–12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044–1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6–9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12–17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere–Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8–3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.This work made use of data from ASIM. ASIM is an international experiment aboard the International Space Station. ASIM is a mission of the European Space Agency (ESA), funded by ESA and national grants from Denmark, Norway and Spain. ESA PRODEX contracts C 4000115884 (DTU) and 4000123438 (Bergen) support the ASIM Science Data Centre. The science analysis is supported by ESA Topical Team contract 4200019920/06/NL/VJ; European Research Council grant AdG-FP7/2007-2013: n 320839; Research Council of Norway contract 223252/F50 (CoE/BCSS); and Ministerio de Ciencia, Innovación y Universidades grants ESP 2017-86263-C4 and ESP2017-87676-C5-5-R. J.A.F. and P.C.-D. acknowledge support by the Spanish Agencia Estatal de Investigación (grant PGC2018-095984-B-I00) and by the Generalitat Valenciana (PROMETEO/2019/071). P.C.-D. acknowledges the Ramon y Cajal funding (RYC-2015-19074) for supporting his research. M.G. acknowledges support through the Generalitat Valenciana via the grant CIDEGENT/2019/031. A.J.C.-T., J.P.-G., M.D.C.-G. and E.R. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This work is partly based on observations made with the Gran Telescopio Canarias (GTC), installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma. We thank J. D. Scargle for his help with the preliminary time-series analysis and his comments. J.P.-G. also acknowledges funding support from Spanish public funds for research from project PID2019-107061GB-C63 from the ‘Programas Estatales de Generación de Conocimiento y Fortalecimiento Científico y Tecnológico del Sistema de I+D+i y de I+D+i Orientada a los Retos de la Sociedad’ from the Spanish Ministry of Science, Innovation and Universities (MCIU).Peer reviewe
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