1,066 research outputs found

    Turning carbon dots into selenium bearing nanoplatforms with in vitro GPx-like activity and pro-oxidant activity

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    Selenium (Se) has been defined as the “Janus element”, with one face showing antioxidant activity and the other pro-oxidant activity. The biological effect of Se depends on both dose and speciation. Se nanoparticles are attracting major interest, although their large-scale preparation for biomedical applications is not trivial. We hypothesize that acid anhydride-coated carbon dots (AACD) are an attractive platform for preparing nanoparticles containing chemically defined Se. The reaction of AA-CD with 3- selenocyanatopropan-1-amine yields carbon dots bearing selenocyanate and carboxylate groups (CD-SeCN) that allow for tuning the hydrosolubility. CD-SeCN has a Se content of 0.36 μmol per mg of nanoparticles, and they show the typical photoluminescence of carbon dots. The selenocyanate groups (SeCN) exhibited glutathione peroxidase-like activity and cytotoxicity. Data show that antioxidant behavior differs between normal and tumor cells, and the evaluation on HEK293 and A549 cells reveals that the toxicity of CD-SeCN depends on dose, time, and intracellular glutathione (GSH) content. The toxicity of CD-SeCN decreases with the time of incubation and the cell death mechanism switches from necrosis to apoptosis, indicating that CD-SeCN is neutralized. Additionally, high levels of intracellular GSH exert a protective effect. These results support a pharmacological potential in cancers with low levels of intracellular GSH. The use of AA-CD as nanoplatforms is a general strategy that paves the way for the engineering of advanced nanosystemsSpanish institution Ministerio de Ciencia, Innovacion y Universidades (No. CTQ2017- 86125-P)Unit of Excellence in Chemistry Applied to Biomedicine and the EnvironmentCentro de Instrumentacion Cientifica (Universidad de Granada)Universidad de Granada/CBUASpringer Natur

    A Finite Element Method Integrated with Terzaghi's Principle to Estimate Settlement of a Building due to Tunnel Construction

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    This study presents the application of the finite element method integrated with Terzaghi’s principle. The definition of a model in oedometric or confinement conditions for settlement estimation of a building after the construction of a tunnel, including the effect of Terzaghi’s principle, is an unresolved problem. The objectives of this work include the demonstration of the need for a minimum of three methodological states to estimate said settlement. For this, a specific methodology is applied to a case study, with eight load steps and four types of coarse-grained soils. In the studied case, two layers of 50 m and 5 m with different degrees of saturation are overlaying an assumed impermeable rock layer. The excavation of a tunnel of 15 m in diameter at a depth of 30 m with drainage lining inside the tunnel is assumed. The minimum distance from the tunnel’s outline to the mat foundation is 15.8 m. It is determined that the settlement, according to Terzaghi’s principle, is around 11% of the total settlement for the most compacted soil types, reaching 35% for the loose soil type, from the tunnel’s outline. In the mat foundation, it implies an increase in the differential settlement of up to 12%. It shows a nonlinear relationship between some of the variables in the analysis. To detect the collapse due to uplifting the tunnel invert, it was determined that it was not appropriate to model in oedometric conditions. The novelty of the investigation relies on identifying and determining the need for a minimum of three states for methodological purposes for a proper quantification of the total settlement: (i) before the construction of the tunnel, (ii) immediately after the excavation of the tunnel, but without groundwater inflow into the tunnel, and (iii) after the tunnelling, with stabilised groundwater inflow into the tunnel.The authors would like to thank Deryck J. Barker Fraser for the translation of the manuscript. Comments by two anonymous reviewers were extremely helpful in improving the manuscript. The third author acknowledges the support of the Catalan Government through the Fluvial Dynamics Research Group (2021 SGR 01114)

    Criteria to discriminate between wines aged in oak barrels and macerated with oak fragments

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    Wine aging in barrels is carried out to increase stability and achieve more complex aromas. In the last few years, however, the practice of macerating wine with small fragments of toasted oak (chips) has become increasingly common. This conveys similar tastes, aromas, and wooden notes to the wine as those obtained with traditional barrel aging, but much faster and at a fraction of the cost. Without proper regulation, this could lead to fraud if wine macerated with chips is offered as barrel aged wine. In the present study, 75 volatile compounds have been determined by applying gas chromatography–mass spectrometry (MS) and flame ionization detection (FID). It has been found that compounds directly related to the wood have greater discriminative power for telling apart wines aged in barrels from those macerated with oak fragments, but no single compound permits flawless classification. Therefore, we have studied the effect of the addition of oak fragments of different origins, different oak types, different formats and subjected to different toasting processes on a set of 231 samples from 6 Spanish Denominations of Origin wines (DOs), and compared them to those same wines aged in oak barrels. In light of the results, we have developed a set of criteria which allows distinguishing with high degree of accuracy between wines which have been aged in barrels and those macerated with oak fragments. The application of these criteria to different wines allows correct classification in over 90% of cases.Peer ReviewedPublishe

    Single chain variable fragment fused to maltose binding protein: a modular nanocarrier platform for the targeted delivery of antitumorals

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    This work was supported by grants CTQ2014-55474-C2-1-R, CTQ2014-55474-C2-2-R and CTQ2017-86125-P from the Ministerio Economia, Industria y Competitividad (co-financed by FEDER funds). SP is supported by a FPU fellowship (FPU17/ 04749). We acknowledge the University of Granada (Spain) cell culture, animal and microscopy central facilities (CIC-UGR).The use of the specific binding properties of monoclonal antibody fragments such as single-chain variable fragments (ScFv) for the selective delivery of antitumor therapeutics for cancer cells is attractive due to their smaller size, low immunogenicity, and low-cost production. Although covalent strategies for the preparation of such ScFv-based therapeutic conjugates are prevalent, this approach is not straightforward, as it requires prior chemical activation and/or modification of both the ScFv and the therapeutics for the application of robust chemistries. A non-covalent alternative based on ScFv fused to maltose-binding protein (MBP) acting as a binding adapter is proposed for active targeted delivery. MBP-ScFv proves to be a valuable modular platform to synergistically bind maltose-derivatized therapeutic cargos through the MBP, while preserving the targeting competences provided by the ScFv. The methodology has been tested by using a mutated maltose-binding protein (MBP I334W) with an enhanced affinity toward maltose and an ScFv coding sequence toward the human epidermal growth factor receptor 2 (HER2). Non-covalent binding complexes of the resulting MBP-ScFv fusion protein with diverse maltosylated therapeutic cargos (a near-infrared dye, a maltosylated supramolecular beta-cyclodextrin container for doxorubicin, and non-viral polyplex gene vector) were easily prepared and characterized. In vitro and in vivo assays using cell lines that express or not the HER2 epitope, and mice xenografts of HER2 expressing cells demonstrated the capability and versatility of MBP-ScFv for diagnosis, imaging, and drug and plasmid active targeted tumor delivery. Remarkably, the modularity of the MBP-ScFv platform allows the flexible interchange of both the cargos and the coding sequence for the ScFv, allowing ad hoc solutions in targeting delivery without any further optimization since the MBP acts as a pivotal element.Ministerio Economia, Industria y Competitividad - FEDER funds CTQ2014-55474-C2-1-R CTQ2014-55474-C2-2-R CTQ2017-86125-PSpanish Government FPU17/0474

    Amphiphilic-like carbon dots as antitumoral drug vehicles and phototherapeutical agents

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    The work was financially supported by the Spanish institutions Ministerio de Ciencia, Innovacion y Universidades (PGC2018-098770-B-I00 and CTQ2017-86125-P) and Junta de Andalucia (ProgramaOperativo FEDER 2014-2020, grants B-FQM-141-UGR18, A1-FQM-341-UGR-18, C-FQM-497-UGR18).Water-insoluble carbon dots are recognized as promising materials, although their applications in nanomedicine are rarely explored, despite their lipophilic character and foreseen compatibility with biological membranes. In this article, we exploit the anhydride functionalization of carbon dots obtained by thermolysis of citric acid to synthesize amphiphilic-like carbon dots (LCDs) by reaction with alkyl amines. A differential feature of this approach is that the hydrophobicity of LCDs is a balance between the ionization of the carboxylic groups resulting from the reaction and the hydrophobicity from the grafted amines. The alkyl chains allow LCDs to entrap hydrophobic molecules and the ionization of the carboxylic groups increases the hydrosolubility, permitting the transfer between organic and aqueous phases. The biomedical interest of these features is illustrated by analyzing the application of LCDs as carriers of the drug campothecin and their evaluation on a battery of cancer cell lines, as well as the transformation of LCDs into a phototherapeutic agent by the formation of a complex with IR780 dye. Results demonstrate that LCDs behave as nanocarriers in a manner that resembles other supramolecular hosts with two differential features: (i) the length of the alkyl chains determines the size of the hosted guest, and (ii) the hydrosolubility of the complex can be modulated by pH.Ministerio de Ciencia, Innovacion y Universidades PGC2018-098770-B-I00 CTQ2017-86125-PJunta de Andalucia B-FQM-141-UGR18 A1-FQM-341-UGR-18 C-FQM-497-UGR1

    Differentiation of bee pollen samples according to their intact-glucosinolate content using canonical discriminant analysis

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    Producción CientíficaA study is presented of the real possibilities of glucosinolate content and chemometrics (canonical discriminant analysis) to differentiate bee pollen samples from four different apiaries (Fuentelahiguera, Monte, Pistacho, Tío Natalio) located in the same geographical area. Fifteen intact-glucosinolates were quantified by means of ultraperformance liquid chromatography coupled to a quadrupole time-of-flight mass detector in forty-nine bee pollen samples. Glucosinolate residues were detected in most of the samples, and these differed in number and concentration. It was possible to directly differentiate one of the apiaries (Fuentelahiguera) from the other three (Monte, Pistacho y Tío Natalio) by comparing glucosinolate content. These three apiaries were differentiated by means of the first two canonical variables obtained from a canonical discriminant analysis. Following this analysis, more than 88% of the samples could be assigned correctly to the Pistacho and Monte apiaries, and 100% to the Tío Natalio apiary.Este trabajo forma parte de los proyectos de investigación financiados por el Ministerio de Economía y Competitividad e INIA-FEDER (RTA2015-00013-C03-01 y 03)

    Applied methodology based on HEC-HMS for reservoir filling estimation due to soil erosion

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    Authors propose a beneficial methodology for hydrological planning in their study. Prospective evaluations of the basins' net capacity can be done using the technique presented. The HEC-HMS (Hydrologic Modelling System) software can be used to estimate in a basin, the sediment emitted. For a certain precipitation, this methodology allows estimating, within a certain range, the gradual blockage of a reservoir, and even a projected date for total blockage. This has some applications to adopt corrective measures that prevent or delay the planned blockage deadlines. The model is of the semi-distributed type, estimating the generation and emission of sediments by sub-basins. The integration of different return periods in HEC-HMS with a semi-distributed model by sub-basins and the application of a mathematical model are the differentiating element of this research. The novelty of this work is to allow prognosing the reservoir sedimentation rate of basins in a local and regional scale with a medium and large temporary framework. The developed methodology allows public institutions to take decisions concerning hydrological planning. It has been applied to the case of "Charco Redondo"reservoir, in Cádiz, Andalusia, in southern Spain. Applying the methodology to this case, an average soil degradation of the reservoir basin has been estimated. Therefore, it is verified that in 50 years the reservoir is expected to lose 8.4% of its capacity

    Population structure and gene flow of Geoffroy's cat (Leopardus geoffroyi) in the Uruguayan Savanna ecoregion

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    Felids are among the species most threatened by habitat fragmentation resulting from land-use change. In the Uruguayan Savanna ecoregion, about 30% of natural habitats have been lost, large felids have been eradicated from most of the region, and the impact of anthropogenic threats over the smaller species that remain is unknown. To develop management strategies, it is important to enhance knowledge about species population structure and landscape connectivity, particularly when land-use change will continue and intensify in the next years. In this study, we evaluate the population structure and gene flow of Geoffroy's cat in the Uruguayan Savanna ecoregion. We generated a matrix of 11 microsatellite loci for 70 individuals. Based on Bayesian approaches we found that within the Uruguayan Savanna, Geoffroy's cat shows high levels of genetic variability and no population structure. However, we observed genetic differences between individuals from the Uruguayan Savanna and those from the contiguous ecoregion, the Argentinian Humid Pampa. Four first-generation migrants from Humid Pampa were identified in the Uruguayan Savanna, suggesting a stronger gene flow in the west-east direction. We detected a past bottleneck followed by a subsequent recovery in Geoffroy's cat populations in both ecoregions. These results lay the groundwork to understand the population dynamics and conservation status of Geoffroy's cat in the Uruguayan Savanna ecoregion, and provide baseline data to establish population monitoring.Fil: Bou, Nadia. Ministerio de Educacion y Cultura.; UruguayFil: Soutullo, Álvaro. Universidad de la Republica; UruguayFil: Hernández, Daniel. Laboratorio de Control Ambiental; UruguayFil: Mannise, Natalia. Ministerio de Educacion y Cultura.; UruguayFil: González, Susana. Ministerio de Educacion y Cultura.; UruguayFil: Bartesaghi, Lucía. Ministerio de Educacion y Cultura.; UruguayFil: Pereira, Javier Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Merino, Mariano Lisandro. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Junín); ArgentinaFil: Espinosa, Caroline. Universidade Federal do Rio Grande do Sul; BrasilFil: Trigo, Tatiane C.. Museu de Ciencias Naturais; ArgentinaFil: Cosse, Mariana. Ministerio de Educacion y Cultura.; Urugua

    Differentiation of bee pollen samples according to the apiary of origin and harvesting period based on their amino acid content

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    Producción CientíficaBee pollen is currently one of the most widely consumed dietary supplements due to its high nutritional value and its potentially beneficial effects on health. Unfortunately, in recent years an increase in the fraudulent marketing of this product has been detected, mainly in terms of adulteration with pollen from other sources. This has made it necessary to seek new tools to ensure its authentication. Therefore, this study investigates the use of free amino acids as markers of the geographical origin and harvesting period of bee pollen. To demonstrate their potential as biomarkers, 72 samples from four apiaries (Pistacho, Tío Natalio, Monte and Fuentelahiguera), located in the same geographical area (Marchamalo, Guadalajara, Spain), were analyzed by liquid chromatography-fluorescence detection, with the data obtained undergoing canonical discriminant analysis. Variable amounts and numbers of free amino acids were found in the samples analyzed; proline predominated in all of them, in a concentration range of 298–569989 mg/kg. The differences observed in amino acid composition could be attributed to the flowering plants from which the bee pollen samples originated. In addition, it was possible to statistically assign over 75% of the samples to the corresponding apiary of origin, the best results being obtained for the Fuentelahiguera and Tío Natalio apiaries (100%); this classification was even superior in the case of the harvesting periods, as more than 90% of the samples were correctly assigned, and in one period (June) a 100% rate was obtained.Ministerio de Economía, Industria y Competitividad (projects RTA 2015-00013-C03-01 and RTA 2015-00013-C03-03
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