64 research outputs found

    Microwave-Assisted Extraction of Curcuma longa L. Oil: Optimization, Chemical Structure and Composition, Antioxidant Activity and Comparison with Conventional Soxhlet Extraction

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    Curcuma root (Curcuma longa L.) is a very important plant in gastronomy and medicine for its unique antiseptic, anti-inflammatory, antimicrobial and antioxidant properties. Conventional methods for the extraction of curcuma oil require long extraction times and high temperatures that can degrade the active substances. Therefore, the objectives of the present study were: (i) first, to optimize the extraction yield of curcuma oil by applying a Box-Behnken experimental design using surface response methodology to the microwave-assisted extraction (MAE) technique (the independent variables studied were reaction time (10–30 min), microwave power (150–200 W) and curcuma powder/ethanol ratio (1:5–1:20; w/v); and, (ii) second, to assess the total phenolic content (TPC) and their antioxidant activity of the oil (at the optimum conditions point) and compare with the conventional Soxhlet technique. The optimum conditions for the MAE were found to be 29.99 min, 160 W and 1:20 w/v to obtain an optimum yield of 10.32%. Interestingly, the oil extracted by microwave-assisted extraction showed higher TPC and better antioxidant properties than the oil extracted with conventional Soxhlet technique. Thus, it was demonstrated that the method applied for extraction influences the final properties of the extracted Curcuma longa L. oil.This research was funded by the Basque Country Government (IT 1008-16)

    Effect of Yb concentration on the resistivity and lifetime of CdTe:Ge:Yb codoped crystals

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    The resistivity and electron lifetime of CdTe:Ge:Yb crystals are reported, demonstrating that the effect of Yb concentration is crucial for accurate electrical compensation. It is also demonstrated that the codoping of CdTe with Ge as deep donor and with Yb as rare-earth element could be a promising way to obtain semiinsulating CdTe crystals with good transport properties. High resistivity 5 10 9 cm and lifetime 9 s were obtained, thus confirming the beneficial effect of rare-earth dopingThis work has been partly supported by the projects CAM SENSORCDT S-0505/MAT/0209, CAM FOTOFLEX S-0505/ENE-123, and EU FP6 PHOLOGIC 017158. E.S. also acknowledges the Spanish MEC for the fellowship FPU 2003-1388.Peer reviewe

    Eco-friendly isolation and characterization of nanochitin from different origins by microwave irradiation: optimization using response surface methodology

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    [EN] The extraction of nanochitin from marine waste has attracted great industrial interest due to its unique properties, namely biodegradability, biocompatibility and as a functional reinforcing agent. Conventional acid hydrolysis isolation of nanochitin requires high temperatures and acid concentration, time and energy. Herein, for the first time, microwave irradiation method was used as an eco-friendly approach to isolate nanochitin from different sources. The isolation conditions were optimized through an experimental Box-Behnken design using surface response methodology. The data showed optimal conditions of 1 M HCl, 10.00 min and 124.75 W to obtain lobster nanocrystals; 1 M HCl, 14.34 min and 50.21 W to obtain shrimp nanocrystals; and 1 M HCl, 29.08 min and 54.08 W to obtain squid pen nanofibres, reducing time and HCl concentration. The obtained isolation yields where of 85.30, 79.92 and 80.59 % for lobster, shrimp and squid, respectively. The morphology of the nanochitins was dependent of the chitin origin, and the lengths of the nanochitins were of 314.74, 386.12 and > 900 nm for lobster, shrimp and squid pen, respectively. The thermal stability of the ensuing nanochitins was maintained after treatment. The results showed that nanochitin could be obtained by using an eco-friendly approach like microwave irradiation.The authors would like to thank the Basque Government (scholarship of young researchers training and project IT1008-16) for supporting financially this research and their gratitude for technical and human support provided by SGIker (UPV/EHU/ERDF, EU). S.C.M.F. is the recipient of an E2S UPPA Research Partnership Chair (MANTA: Marine Materials) supported by the “Investissements d’Avenir” French program managed by ANR (ANR-16-IDEX-0002), the R ́egion Nouvelle-Aquitaine and the Communaut ́e d’Agglom ́eration du Pays Basque, France

    Effect of Deterpenated Origanum majorana L. Essential Oil on the Physicochemical and Biological Properties of Chitosan/β-Chitin Nanofibers Nanocomposite Films

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    Herein, the effect of three deterpenated fractions from Origanum majorana L. essential oil on the physicochemical, mechanical and biological properties of chitosan/β-chitin nanofibers-based nanocomposite films were investigated. In general, the incorporation of Origanum majorana L. original essential oil or its deterpenated fractions increases the opacity of the nanocomposite films and gives them a yellowish color. The water solubility decreases from 58% for chitosan/β-chitin nanofibers nanocomposite film to around 32% for the nanocomposite films modified with original essential oil or its deterpenated fractions. Regarding the thermal stability, no major changes were observed, and the mechanical properties decreased. Interestingly, data show differences on the biological properties of the materials depending on the incorporated deterpenated fraction of Origanum majorana L. essential oil. The nanocomposite films prepared with the deterpenated fractions with a high concentration of oxygenated terpene derivatives show the best antifungal activity against Aspergillus niger, with fungal growth inhibition of around 85.90%. Nonetheless, the only nanocomposite film that does not present cytotoxicity on the viability of L929 fibroblast cells after 48 and 72 h is the one prepared with the fraction presenting the higher terpenic hydrocarbon content (87.92%). These results suggest that the composition of the deterpenated fraction plays an important role in determining the biological properties of the nanocomposite films.This research was funded by the Basque Country Government (IT 1008-16)

    Cylindrospermopsin-microcystin-LR combinations may induce genotoxic and histopathological damage in rats

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    Cylindrospermopsin (CYN) and microcystins (MC) are cyanotoxins that can occur simultaneously in contaminated water and food. CYN/MC-LR mixtures previously investigated in vitro showed an induction of micronucleus (MN) formation only in the presence of the metabolic fraction S9. When this is the case, the European Food Safety Authority recommends a follow up to in vivo testing. Thus, rats were orally exposed to 7.5 + 75, 23.7 + 237, and 75 + 750 μg CYN/MC-LR/kg body weight (b.w.). The MN test in bone marrow was performed, and the standard and modified comet assays were carried out to measure DNA strand breaks or oxidative DNA damage in stomach, liver, and blood cells. The results revealed an increase in MN formation in bone marrow, at all the assayed doses. However, no DNA strand breaks nor oxidative DNA damage were induced, as shown in the comet assays. The histopathological study indicated alterations only in the highest dose group. Liver was the target organ showing fatty degeneration and necrotic hepatocytes in centrilobular areas, as well as a light mononuclear inflammatory periportal infiltrate. Additionally, the stomach had flaking epithelium and mild necrosis of epithelial cells. Therefore, the combined exposure to cyanotoxins may induce genotoxic and histopathological damage in vivo.Ministerio de Economía y Competitividad AGL2015-64558-

    Integración de experiencias en investigación y didáctica en la cátedra de Psiquiatría

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    En la cátedra de Psiquiatría (Facultad de Ciencias Medicas, UNLP) durante el periodo 2011-2012, se llevó a cabo el proyecto de investigación “Victimización y Trastorno por estrés postraumático”. En el mismo participaron alumnos y docentes entrevistando a comerciantes de la Ciudad de La Plata, para detectar víctimas de asaltos y evaluar sus consecuencias para la salud mental. Posteriormente se evaluó el proceso didáctico encuestando a todos los participantes. Este informe describe el aprovechamiento y las percepciones de estudiantes y docentes que participaron de la experiencia. Indagar percepciones de alumnos y docentes sobre la experiencia de participar en un proyecto de investigación y dimensionar los resultados de aprendizaje y la valoración personal de la experiencia.Facultad de Ciencias Médica
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