162 research outputs found

    Chemical Composition and Cytoprotective Activities of Methanolic Extract of Asplenium adiantum-nigrum L. (Aspleniaceae)

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    Ferns can be a source of polyphenolic compounds, with the fronds being the main parts described in ethnopharmacological studies. The present study screened polyphenolic phytochemicals and evaluated in vitro activities of a methanolic extract of Asplenium adiantum-nigrum L. fronds (AAM), an Aspleniaceae fern collected from the Prades mountains (Tarragona, Spain). Phytocharacterization by HPLC-MS/MS confirmed that the major flavonoids isolated in AAM are flavanols while the major phytochemicals are phenol acids, with chlorogenic acid being the most representative one. Cytotoxicity, cytoprotection, cellular repair activity, and phototoxicity were determined in vitro in the presence of 0.01, 0.1, and 1 mg/mL of the extract. No cytotoxicity was obtained in any of the cell lines tested: non-tumoral (3T3 and HaCaT) and tumoral (HeLa, HepG2, and A549) cells. Additionally, the polyphenolic extract showed greater protective effect against H2O2 in 3T3 than HaCaT cells. Despite the low total phenolic content of AAM (1405.68 mg phenolic phytochemicals/kg dry extract), the cytoprotective activity of this extract could be associated with the synergistic antioxidant action of their polyphenolic profile. In addition, the extract did not present phototoxicity against the non-cytotoxic 1.8 J/cm2 dose of UVA light in both non-tumoral cell lines

    Generación de electricidad en horas de punta a partir de la digestión anaeróbica de camalote

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    El presente trabajo tiene como objeto de presentar una propuesta novedosa y sustentable para la generación de energía eléctrica en el área metropolitana de Asunción basada en una fuente renovable de energía. Dicha generación se realizaría principalmente en horas de punta con el fin de reducir la potencia contratada por la ANDE en las usinas existentes y de esta forma disminuir costos y al mismo tiempo estabilizar las redes de transmisión y de distribución en la zona de Asunción. La electricidad se generaría en una planta térmica de ciclo combinado de 130 MW de potencia instalada utilizando como combustible biogás obtenido por medio de la digestión anaeróbica en biodigestores de plantas de camalote cultivadas en piletas a ser construidas en la orilla del río Paraguay frente al Jardín Botánico de Asunción. La principal ventaja para el aprovechamiento del camalote es su elevado índice de crecimiento, que es entre 100 y 500 g por día y por m2 según las condiciones ambientales, lo que permite que se duplique su masa vegetal cada 6 a 15 días. La relación entre carbono y nitrógeno, que se encuentra en su masa vegetal es óptima para la generación de biogás, cuyo poder calorífico de unos 6,4 kWh/m3 es suficientemente elevado para utilizarlo para la generación de calor y por ende también de electricidad en una planta térmica. Esa usina podría conectarse directamente al SIN a través de la Estación de Puerto Botánico mediante una línea de transmisión en 220 kV de 2 km cruzando el río Paraguay. Mediante este proyecto la ANDE podría ahorrar por año hasta US25,000,000enconceptodelacontratacioˊndepotenciaenlarepresadeItaipuˊ.Aunquedichoahorrosereducirıˊacadaan~ode3 25,000,000 en concepto de la contratación de potencia en la represa de Itaipú. Aunque dicho ahorro se reduciría cada año de 3% por el incremento de la demanda, la inversión de unos US 98,000,000 podría ser amortizada en un plazo de 15 años y tendrá un TIR del 5% y un VAN de US40,548,000TheobjectiveofthepresentpaperistopresentaninnovativeandsustainableproposalforgeneratingelectricityinthemetropolitanareaofAsuncion,thecapitalofParaguay,basedonarenewablesourceofenergy.ElectricitywouldmainlybegeneratedduringpeakhourswiththeaimofreducingpowercontractedbytheParaguayanElectricityAdministration(ANDE)fromexistinghydroelectricpowerplantsandthusreducecostsandstabilisetransmissionanddistributiongridsintheareaofAsuncion.Electricitywouldbegeneratedata130MWcombinedcyclethermalpowerplantusingbiogasasfuel,thisbeingobtainedbyanaerobicdigestionofwaterhyacinthscultivatedinpools,whichwouldbebuiltonthebanksoftheParaguayriveroppositeAsuncionsbotanicalgarden.Themainadvantageofusingwaterhyacinthsistheirhighgrowthrate,thisbeing100to500g/day/m2dependingonenvironmentalconditions,therebyallowingplantmasstodoubleevery6to15days.Additionally,carbontonitrogenratioinwaterhyacinthvegetalmassisoptimumforbiogasgeneration.About6.4kWh/m3biogascalorificvalueishighenoughtobeusedforproducingheatand,therefore,forgeneratingelectricityinathermalpowerplant.SuchpowerplantcouldbedirectlyconnectedtothenationalgridthroughthePuertoBotanictransformerstationbybuildinga2kmlong220kVtransmissionlinecrossingtheParaguayRiver.ThisprojectcouldsaveANDEupto25millionUS 40,548,000The objective of the present paper is to present an innovative and sustainable proposal for generating electricity in the metropolitan area of Asuncion, the capital of Paraguay, based on a renewable source of energy. Electricity would mainly be generated during peak hours with the aim of reducing power contracted by the Paraguayan Electricity Administration (ANDE) from existing hydroelectric power plants and thus reduce costs and stabilise transmission and distribution grids in the area of Asuncion. Electricity would be generated at a 130 MW combined cycle thermal power plant using biogas as fuel, this being obtained by anaerobic digestion of water hyacinths cultivated in pools, which would be built on the banks of the Paraguay river opposite Asuncion’s botanical garden. The main advantage of using water hyacinths is their high growth rate, this being 100 to 500 g/day/m2 depending on environmental conditions, thereby allowing plant mass to double every 6 to 15 days. Additionally, carbon to nitrogen ratio in water hyacinth vegetal mass is optimum for biogas generation. About 6.4 kWh/m3 biogas calorific value is high enough to be used for producing heat and, therefore, for generating electricity in a thermal power plant. Such power plant could be directly connected to the national grid through the Puerto Botanic transformer station by building a 2 km long 220 kV transmission line crossing the Paraguay River. This project could save ANDE up to 25 million US every year due to reduced contracted power at the Itaipu power plant. Although this reduction will decline by 3% each year due to increased electricity demand, the investment of around 98 million UScouldberepaidwithin15yearsandwouldhave5 could be repaid within 15 years and would have 5% IRR and US 40.5 million NPV

    Polygenic determinants of white matter volume derived from GWAS lack reproducibility in a replicate sample

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    A recent publication reported an exciting polygenic effect of schizophrenia (SCZ) risk variants, identified by a large genome-wide association study (GWAS), on total brain and white matter volumes in schizophrenic patients and, even more prominently, in healthy subjects. The aim of the present work was to replicate and then potentially extend these findings. According to the original publication, polygenic risk scores using single nucleotide polymorphism (SNP) information of SCZ GWAS (polygenic SCZ risk scores; PSS) were calculated in 122 healthy subjects, enrolled in a structural magnetic resonance imaging (MRI) study. These scores were computed based on P-values and odds ratios available through the Psychiatric GWAS Consortium. In addition, polygenic white matter scores (PWM) were calculated, using the respective SNP subset in the original publication. None of the polygenic scores, either PSS or PWM, were found to be associated with total brain, white matter or gray matter volume in our replicate sample. Minor differences between the original and the present study that might have contributed to lack of reproducibility (but unlikely explain it fully), are number of subjects, ethnicity, age distribution, array technology, SNP imputation quality and MRI scanner type. In contrast to the original publication, our results do not reveal the slightest signal of association of the described sets of GWAS-identified SCZ risk variants with brain volumes in adults. Caution is indicated in interpreting studies building on polygenic risk scores without replication sample

    MSWI bottom ash for thermal energy storage: An innovative and sustainable approach for its reutilization

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    The management of Municipal Solid Waste (MSW) is a very important issue that must be dealt by the perspective of the 3 Rs (Reuse, reduce, recycle. MSW incineration bottom ash (BA) accounts for 85-95% of the total solids that remained after incineration. Finding suitable alternatives for its revalorization is very attractive, especially in terms of environmental sustainability. Thermal energy storage (TES) is a complementary technology of renewable energy. The aim of this study is to evaluate the thermophysical properties of weathered BA (WBA) in order to find suitable alternatives for its valorisation. Several samples of WBA were collected from a waste-to-energy facility located in Tarragona (Spain). This facility sieved to different size fractions. Each size fraction was characterized with respect its physicochemical properties and the energy density (ren) was calculated. The results obtained showed that this residue is a suitable alternative candidate material for TES as it presents an energy density of 1461.2 kJ m 3 K 1 for the 1-2 mm fraction. In addition, the low cost of this type of residue (0.6V per t) and its high production rate per year makes it an attractive and sustainable alternative for TES

    Protective effect of guarana-loaded liposomes on hemolytic activity

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    Paullinia cupana var. sorbilis (Mart.) Ducke, popularly known as guarana, is one of the most promising plants in Brazilian flora and has attracted considerable interest from the scientific community owing to its numerous therapeutic activities and less side effects. Hence, using nanotechnology is a viable alternative to primarily improve the physicochemical characteristics and bioavailability of guarana. The objective of the present study was to develop, characterize, and evaluate the stability of liposomes containing guarana powder and to evaluate their antioxidant and hemolytic activity in vitro. Three different concentrations of guarana powder and two methods of liposome preparation were tested. Liposomes were developed and characterized, and their stability was analyzed by evaluating physicochemical parameters. Hemolytic activity of guarana liposomal formulation (G-Lip) was compared with that of guarana in its free form (FG) and of liposome without guarana (W-Lip). Red blood cells from rats were exposed to these different formulations dissolved in phosphate buffer solution (PBS; pH 7.4). The best stability was achieved for the formulation containing 1 mg.mL−1 guarana powder produced by the reverse phase evaporation method. FG showed dose-dependent antioxidant activity, which was maintained in G-Lip. W-Lip showed high hemolytic activity in PBS at pH 7.4 possibly because of the presence of polysorbate 80, and on addition of guarana to these structures, the hemolytic process was reversed. The same protective effect was observed for FG. It is believed that the complex structure of guarana, primarily the presence of polyphenols, exerts a powerful antioxidant action, helping to protect erythrocytes

    Objetos de oro y epicampaniforme en la Cova del Gegant. Relaciones en la costa mediterránea de la Península Ibérica durante la Edad del Bronce

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    En este trabajo se analiza el estrato XXV de la Cova del Gegant (Sitges, Barcelona), adscrito a la Edad del Bronce, y se destaca la problemática cronológica de este período. En este yacimiento encontramos decoraciones epicampaniformes del "Grupo del Nordeste", tradicionalmente atribuidas a un Bronce Antiguo, un osario colectivo datado por C14 en el Bronce Medio, ornamentos en ámbar/resina de amplia cronología y dos piezas áureas, muy escasas en el nordeste de la Península Ibérica, que vinculamos con el episodio sepulcral. Las piezas arqueológicas y la serie de dataciones radiocarbónicas nos proporcionan datos importantes sobre las redes de intercambio y los desplazamientos a lo largo de la fachada mediterránea de la Península Ibérica durante la Edad de Bronce

    GRB minimum variability timescale with Insight-HXMT and Swift: implications for progenitor models, dissipation physics and GRB classifications

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    The dissipation process of GRB prompt emission is still unknown. Study of temporal variability may provide a unique way to discriminate the imprint of the inner engine activity from geometry and propagation related effects. We define the minimum variability timescale (MVT) as the shortest duration of individual pulses that shape a light curve for a sample of GRBs and test correlations with peak luminosity, Lorentz factor, and jet opening angle. We compare these correlations with predictions from recent numerical simulations for a relativistic structured -- possibly wobbling -- jet and assess the value of MTV as probe of prompt-emission physics. We used the peak detection algorithm mepsa to identify the shortest pulse within a GRB time history and estimate its full width half maximum (FWHM). We applied this framework to two sets of GRBs: Swift (from 2005 to July 2022) and Insight-HXMT (from June 2017 to July 2021, including 221009A). We then selected 401 GRBs with measured z to test for correlations. On average short GRBs have significantly shorter MVT than long GRBs. The MVT distribution of short GRBs with extended emission such as 060614 and 211211A is compatible only with that of short GRBs. This provides a new clue on the progenitor's nature. The MVT for long GRBs anticorrelates with peak luminosity. We confirm the anticorrelation with the Lorentz factor and find a correlation with the jet opening angle as estimated from the afterglow, along with an inverse correlation with the number of pulses. The MVT can identify the emerging putative new class of long GRBs that are suggested to be produced by compact binary mergers. For otherwise typical long GRBs, the different correlations between MVT and peak luminosity, Lorentz factor, jet opening angle, and number of pulses can be explained within the context of structured, possibly wobbling, weakly magnetised relativistic jets. (summarised)Comment: 18 pages, 15 figures, accepted by A&
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