99 research outputs found

    Materiales biomiméticos de base carbono para electrodos en sistemas de almacenamiento de energía

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    En este trabajo se demuestra la posibilidad de inducir cristalinidad en materiales carbonosos obtenidos mediante pirólisis de precursores celulósicos naturales, utilizando un metal de transición como catalizador para producir grafitización in situ durante el proceso de pirólisis. En ausencia de catalizador se obtienen carbones duros o isotrópicos por este procedimiento. Las maderas precursoras se han impregnado con disoluciones que contienen hierro o níquel previamente al proceso de pirólisis, obteniendo materiales monolíticos grafíticos que combinan las propiedades del carbón obtenido mediante pirólisis, como un gran volumen de poros, porosidad abierta e interconectada y elevadas áreas superficiales, con las propiedades del grafito, como un alto grado de cristalinidad y una elevada conductividad eléctrica. El aumento en la cristalinidad y el orden estructural de los materiales obtenidos ha sido demostrado mediante microscopía electrónica, difracción de rayos X y espectroscopía Raman, e indirectamente mediante el incremento de la conductividad eléctrica. Curvas isotermas tipo IV características de materiales mesoporosos se han obtenido para carbones tratados, así como un incremento de hasta dos órdenes de magnitud en las áreas superficiales BET obtenidas respecto a carbones sin tratar. Tras la caracterización exhaustiva de los materiales obtenidos, se ha evaluado su comportamiento como electrodos en sistemas de almacenamiento de energía, obteniendo en carbones tratados elevadas capacitancias en electrolitos acuosos, alcanzando valores en voltametría cíclica superiores a 100 F · g-1 y una excelente estabilidad cíclica de los electrodos sin reducción de la capacitancia inicial tras 1000 ciclos en voltametría. Estos valores se encuentran próximos a los que presentan los supercondensadores comerciales actualmente. El material presenta una estructura porosa monolítica en la que toda la masa es activa y no necesita aditivos para su empleo en dispositivos. Además, estos esqueletos de carbón pueden ser empleados como andamio para depositar en ellos una fase secundaria que proporcione funcionalidad adicional. Se han depositado diferentes óxidos metálicos (SnO2, Nb2O5 y Fe3O4) sobre los carbones, tratados y sin tratar, mediante deposición química en fase vapor (CVD), obteniendo materiales híbridos en los que se ha conseguido mejorar el comportamiento electroquímico de los mismos. El objetivo de la tesis es el desarrollo de un material de carbón poroso monolítico que presente alta cristalinidad, elevada área superficial y una buena conductividad eléctrica, para almacenar energía mediante un mecanismo de doble capa electrostática. Además, debido a la posibilidad de depositar una segunda fase sobre esta estructura porosa, se han obtenido materiales híbridos que pueden almacenar energía mediante dos principios de almacenamiento, electrostático y farádico, contribuyendo ambos a la capacitancia total del material

    Thermal Conductivity of Partially Graphitized Biocarbon Obtained by Carbonization of Medium-Density Fiberboard in the Presence of a Ni-Based Catalyst

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    The thermal conductivity k and resistivity ρ of biocarbon matrices, prepared by carbonizing medium-density fiberboard at Tcarb = 850 and 1500°C in the presence of a Ni-based catalyst (samples MDFC( Ni)) and without a catalyst (samples MDF-C), have been measured for the first time in the temperature range of 5–300 K. X-ray diffraction analysis has revealed that the bulk graphite phase arises only at Tcarb = 1500°C. It has been shown that the temperature dependences of the thermal conductivity of samples MDFC- 850 and MDF-C-850(Ni) in the range of 80–300 K are to each other and follow the law of k(T) ~ T1.65, but the use of the Ni-catalyst leads to an increase in the thermal conductivity by a factor of approximately 1.5, due to the formation of a greater fraction of the nanocrystalline phase in the presence of the Ni-catalyst at Tcarb = 850°C. In biocarbon MDF-C-1500 prepared without a catalyst, the dependence is k(T) ~ T1.65, and it is controlled by the nanocrystalline phase. In MDF-C-1500(Ni), the bulk graphite phase formed increases the thermal conductivity by a factor of 1.5–2 compared to the thermal conductivity of MDF-C-1500 in the entire temperature range of 5–300 K; k(T = 300 K) reaches the values of ~10 W m–1 K–1, characteristic of biocarbon obtained without a catalyst only at high temperatures of Tcarb = 2400°C. It has been shown that MDF-C-1500(Ni) in the temperature range of 40‒300 K is characterized by the dependence, k(T) ~ T1.3, which can be described in terms of the model of partially graphitized biocarbon as a composite of an amorphous matrix with spherical inclusions of the graphite phaseRussian Foundation for Basic Research 14-03- 0049

    Thermal conductivity of Fe graphitized wood derived carbon

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    Graphitic porous carbon materials from pyrolysis of wood precursors were obtained by means of a nanosized Fe catalyst, and their microstructure and electrical and thermal transport properties investigated. Thermal and electrical conductivity of graphitized carbon materials increase with the pyrolysis temperature, indicating a relationship between the degree of graphitization and thus in crystallite size with transport properties in the resulting carbon scaffolds. Evaluation of the experimental results indicate that thermal conductivity is mainly through phonons and increases with the temperature in Fe-catalyzed carbons suggesting that the mean free path of phonons in the material is small and defect scattering dominates over phonon-phonon interactions in the range from room temperature to 800 °C.Junta de Andalucía PE2012-TEP862Ministerio de Economía y Competitividad MAT2013-41233-

    Nota corológica sobre la flora de Extremadura (España)

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    Floristic records for the Flora of Extremadura (Spain)Palabras clave. Badajoz, Cáceres, Corología, Extremadura, Flora. Key words. Badajoz, Cáceres, Corology, Extremadura, Flora

    Identification of the main allergen sensitizers in an Iran asthmatic population by molecular diagnosis

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    Background: There has been a significant growth in the prevalence of allergy, mainly associated to IgE-mediated disorders such as asthma and rhinitis. The identification of atopy in asthmatic patients through the measurement of specific IgE can help to identify risk factors that cause asthmatic symptoms in patients. The development and use of individualized allergen-based tests by the Component Resolved Diagnosis has been a crucial advance in the accurate diagnosis and control of allergic patients. The objective of this work was to assess the usefulness of molecular diagnosis to identify environmental allergens as possible factors influencing the development and manifestation of asthma in a group of asthmatic patients from Iran. Methods: Studied population: 202 adult asthmatic patients treated at the Loghman Hakim Hospital and Pasteur Institute of Teheran (Iran) from 2011 to 2012. Specific IgE determined by the ImmunoCAP system were used to both evaluate the patients' atopic condition and the molecules involved in the allergic sensitization. SDS-PAGE IgE-immunoblotting associated with mass spectrometry was carried out to study the cockroach IgE-binding sensitizing proteins. Results: Forty-five percent of all patients could be considered atopic individuals. Eighty-two percent of atopic patients were sensitized to pollen allergens. The Salsola kali (Sal k 1) and the Phleum pratense (rPhl p 1 and/or rPhl p 5) major allergens were the most common sensitizers among pollens (71% and 18%, respectively). Thirty-five percent of the atopic population was sensitized to cockroach. Four different allergens, including a previously unknown alpha-amylase, were identified in the cockroach extract. No significant associations could be demonstrated between the severity of asthma and the specific IgE levels in the atopic population. Statistical analysis identified the Sal k 1 as the main protein allergen influencing the development and expression of asthma in the studied population. Conclusions: Pollen and cockroach were the most relevant allergen sources in the asthmatic population. The Salsola kali major allergen was the main cause for sensitization in the atopic patients suffering asthma. Using the Component Resolved Diagnosis, it was possible to identify a new Blattella germanica cockroach allergen (Blattella alpha amylase 53 kDa) that could sensitize a relevant percentage of this population.This study has been founded by the Government of The Basque Country, Project IT787-13

    The Integrin Beta1 Modulator Tirofiban Prevents Adipogenesis and Obesity by the Overexpression of Integrin-Linked Kinase: a Pre-Clinical Approach In Vitro and In Vivo

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    de Frutos, S., Griera, M., Hatem-Vaquero, M. et al. The integrin beta1 modulator Tirofiban prevents adipogenesis and obesity by the overexpression of integrin-linked kinase: a pre-clinical approach in vitro and in vivo. Cell Biosci 12, 10 (2022)Background: Obesity is caused by the enlargement of the white adipose tissue (WAT) depots, characterized by the hypertrophic enlargement of malfunctioning adipocytes within WAT which increases the storage of triglycerides (TG) in the lipid droplets (LD). Adipogenesis pathways as well as the expression and activity of some extracellular matrix receptors integrins are upregulated. Integrin?1 (INTB1) is the main isoform involved in WAT remodeling during obesity and insulin resistance-related diseases. We recently described Integrin Linked Kinase (ILK), a scafold protein recruited by INTB1, as an important mediator of WAT remodeling and insulin resistance. As the few approved drugs to fght obesity have brought long-term cardiovascular side efects and given that the consideration of INTB1 and/or ILK modulation as anti-obesogenic strategies remains unexplored, we aimed to evaluate the anti-obesogenic capacity of the clinically approved anticoagulant Tirofban (TF), stated in preclinical studies as a cardiovascular protector. Methods: Fully diferentiated adipocytes originating from C3H10T1/2 were exposed to TF and were co-treated with specifc INTB1 blockers or with siRNA-based knockdown ILK expression. Lipid-specifc dyes were used to determine the TG content in LD. The genetic expression pattern of ILK, pro-infammatory cytokines (MCP1, IL6), adipogenesis (PPAR?, Leptin), thermogenesis (UCP1), proliferation (PCNA), lipid metabolism (FASN, HSL, ATGL), and metabolite trans porters (FABP4, FAT, AQP7) were detected using quantitative PCR. Cytoskeletal actin polymerization was detected by confocal microscopy. Immunoblotting was performed to detect INTB1 phosphorylation at Thr788/9 and ILK activity as phosphorylation levels of protein kinase B (AKT) in Ser473 and glycogen synthase kinase 3? (GSK3?) at Ser9. TF was intraperitoneally administered once per day to wildtype and ILK knockdown mice (cKDILK) challenged with a high-fat diet (HFD) or control diet (STD) for 2 weeks. Body and WAT weight gains were compared. The expression of ILK and other markers was determined in the visceral epididymal (epi) and inguinal subcutaneous (sc) WAT. Results: TF reduced TG content and the expression of adipogenesis markers and transporters in adipocytes, while UCP-1 expression was increased and the expression of lipases, cytokines or PCNA was not afected. Mechanistically, TF rapidly increased and faded the intracellular phosphorylation of INTB1 but not AKT or GSK3?. F-actin levels were rapidly decreased, and INTB1 blockade avoided the TF efect. After 24 h, ILK expression and phosphorylation rates of AKT and GSK3? were upregulated, while ILK silencing increased TG content. INTB1 blockade and ILK silencing avoided TF efects on the TG content and the transcriptional expression of PPAR? and UCP1. In HFD-challenged mice, the systemic administration of TF for several days reduced the weight gain on WAT depots. TF reduced adipogenesis and pro-infammatory biomarkers and increased lipolysis markers HSL and FAT in epiWAT from HFD, while increased UCP1 in scWAT. In both WATs, TF upregulated ILK expression and activity, while no changes were observed in other tissues. In HFD-fed cKDILK, the blunted ILK in epiWAT worsened weight gain and avoided the anti-obesogenic efect of in vivo TF administration. Conclusions: ILK downregulation in WAT can be considered a biomarker of obesity establishment. Via an INTB1-ILK axis, TF restores malfunctioning hypertrophied WAT by changing the expression of adipocyte-related genes, increas ing ILK expression and activity, and reducing TG storage. TF prevents obesity, a property to be added to its anticoagu lant and cardiovascular protective advantages.Instituto de Salud Carlos IIIComunidad de MadridFondo Europeo de Desarrollo Regional-FEDE

    Signatures of selection for bonamiosis resistance in European flat oyster (Ostrea edulis): New genomic tools for breeding programs and management of natural resources

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    The European flat oyster (Ostrea edulis) is a highly appreciated mollusk with an important aquaculture production throughout the 20th century, in addition to playing an important role on coastal ecosystems. Overexploitation of natural beds, habitat degradation, introduction of non‐native species, and epidemic outbreaks have severely affected this important resource, particularly, the protozoan parasite Bonamia ostreae, which is the main concern affecting its production and conservation. In order to identify genomic regions and markers potentially associated with bonamiosis resistance, six oyster beds distributed throughout the European Atlantic coast were sampled. Three of them have been exposed to this parasite since the early 1980s and showed some degree of innate resistance (long‐term affected group, LTA), while the other three were free of B. ostreae at least until sampling date (naïve group, NV). A total of 14,065 SNPs were analyzed, including 37 markers from candidate genes and 14,028 from a medium‐density SNP array. Gene diversity was similar between LTA and NV groups suggesting no genetic erosion due to long‐term exposure to the parasite, and three population clusters were detected using the whole dataset. Tests for divergent selection between NV and LTA groups detected the presence of a very consistent set of 22 markers, located within a putative single genomic region, which suggests the presence of a major quantitative trait locus associated with B. ostreae resistance. Moreover, 324 outlier loci associated with factors other than bonamiosis were identified allowing fully discrimination of all the oyster beds. A practical tool which included the 84 highest discriminative markers for tracing O. edulis populations was developed and tested with empirical data. Results reported herein could assist the production of stocks with improved resistance to bonamiosis and facilitate the management of oyster beds for recovery production and ecosystem services provided by this species.This work was funded by the OYSTERECOVER project (FP7‐SME‐2008‐2‐243583) from the European Community's Seventh Framework Programme, the European Regional Development's funds (FEDER), and Xunta de Galicia local government (GRC2014/010, R2014/046). The development and provision of the medium‐density SNP array for oysters was supported by Biotechnology and Biological Sciences Research Council (BBSRC), and National Environment Research Council (NERC) grants (BB/M026140/1, NE/P010695/1), in addition to BBSRC Institute Strategic Program Grants (BBS/E/D/20002172 and BBS/E/D/30002275)S

    Reduced L-carnitine transport in aortic endothelial cells from spontaneously hypertensive rats

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    Impaired L-carnitine uptake correlates with higher blood pressure in adult men, and L-carnitine restores endothelial function in aortic rings from spontaneously hypertensive rat (SHR). Thus, endothelial dysfunction in hypertension could result from lower L-carnitine transport in this cell type. L-Carnitine transport is mainly mediated by novel organic cation transporters 1 (Octn1, Na+-independent) and 2 (Octn2, Na+-dependent); however, their kinetic properties and potential consequences in hypertension are unknown. We hypothesize that L-carnitine transport kinetic properties will be altered in aortic endothelium from spontaneously hypertensive rats (SHR). L-Carnitine transport was measured at different extracellular pH (pHo 5.5–8.5) in the absence or presence of sodium in rat aortic endothelial cells (RAECs) from non-hypertensive Wistar-Kyoto (WKY) rats and SHR. Octn1 and Octn2 mRNA relative expression was also determined. Dilation of endothelium-intact or denuded aortic rings in response to calcitonine gene related peptide (CGRP, 0.1–100 nmol/L) was measured (myography) in the absence or presence of L-carnitine. Total L-carnitine transport was lower in cells from SHR compared with WKY rats, an effect due to reduced Na+-dependent (Na+dep) compared with Na+-independent (Na+indep) transport components. Saturable L-carnitine transport kinetics show maximal velocity (Vmax), without changes in apparent Km for Na+indep transport in SHR compared with WKY rats. Total and Na+dep component of transport were increased, but Na+indep transport was reduced by extracellular alkalization in WKY rats. However, alkalization reduced total and Na+indep transport in cells from SHR. Octn2 mRNA was higher than Octn-1 mRNA expression in cells from both conditions. Dilation of artery rings in response to CGRP was reduced in vessels from SHR compared with WKY rats. CGRP effect was endothelium-dependent and restored by L-carnitine. All together these results suggest that reduced L-carnitine transport (likely via Na+-dependent Octn2) could limit this compound's potential beneficial effects in RAECs from SHR

    Real-world experience with bezlotoxumab for prevention of recurrence of Clostridioides difficile infection

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    Bezlotoxumab is marketed for the prevention of recurrent Clostridioides difficile infection (rCDI). Its high cost could be determining its prescription to a different population than that represented in clinical trials. The objective of the study was to verify the effectiveness and safety of bezlotoxumab in preventing rCDI and to investigate factors related to bezlotoxumab failure in the real world. A retrospective, multicentre cohort study of patients treated with bezlotoxumab in Spain was conducted. We compared the characteristics of cohort patients with those of patients treated with bezlotoxumab in the pivotal MODIFY trials. We assessed recurrence rates 12 weeks after completion of treatment against C. difficile, and we analysed the factors associated with bezlotoxumab failure. Ninety-one patients were included in the study. The cohort presented with more risk factors for rCDI than the patients included in the MODIFY trials. Thirteen (14.2%) developed rCDI at 12 weeks of follow-up, and rCDI rates were numerically higher in patients with two or more previous episodes (25%) than in those who had fewer than two previous episodes of C. difficile infection (CDI) (10.4%); p = 0.09. There were no adverse effects attributable to bezlotoxumab. Despite being used in a more compromised population than that represented in clinical trials, we confirm the effectiveness of bezlotoxumab for the prevention of rCDI

    Drug-refractory myasthenia gravis : Clinical characteristics, treatments, and outcome

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    Altres ajuts: R. Alvarez-Velasco was supported by grant SLT008/18/00207 from the Health Research and Innovation Strategic Plan (PERIS). The NMD-ES Project and F. PlaJunca (data curator) are partially funded by the Centro de Investigacion Biomédica en Red de Enfermedades Raras (CIBERER).To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment. This observational retrospective cross-sectional multicenter study was based on data from the Spanish MG Registry (NMD-ES). Patients were considered refractory when their MG Foundation of America post-interventional status (MGFA-PIS) was unchanged or worse after corticosteroids and two or more other immunosuppressive agents. Clinical and immunologic characteristics of drug-refractory patients, efficiency and toxicity of drugs used, and outcome (MGFA-PIS) at end of follow-up were studied. We included 990 patients from 15 hospitals. Eighty-four patients (68 of 842 anti-acetylcholine receptor [AChR], 5 of 26 anti-muscle-specific tyrosine kinase [MusK], 10 of 120 seronegative, and 1 of 2 double-seropositive patients) were drug refractory. Drug-refractory patients were more frequently women (p < 0.0001), younger at onset (p < 0.0001), and anti-MuSK positive (p = 0.037). Moreover, they more frequently presented a generalized form of the disease, bulbar symptoms, and life-threatening events (p < 0.0001; p = 0.018; and p = 0.002, respectively) than non-drug-refractory patients. Mean follow-up was 9.8 years (SD 4.5). Twenty-four (50%) refractory patients had side effects to one or more of the drugs. At the end of follow-up, 42.9% of drug-refractory patients (42.6% of anti-AChR, 100% of anti-MuSK, and 10% of seronegative patients) and 79.8% of non-drug-refractory patients (p < 0.0001) achieved remission or had minimal manifestations. Eighty percent of drug-refractory-seronegative patients did not respond to any drug tested. In this study, 8.5% of MG patients were drug-refractory. New more specific drugs are needed to treat drug-refractory MG patients
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