27 research outputs found

    The Role of Graphene for Advanced Electrochemical Energy Storage Devices

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    199 p.En el presente estudio se exploran los beneficios de la integración de materiales basados en grafeno en sistemas de almacenamiento energético avanzados tales como baterías litio-azufre, baterías sodio-oxígeno, condensadores de doble capa y condensadores híbridos de litio-ion. Para ello, se ha llevado a cabo una optimización pormenorizada de la receta de los electrodos basados en grafeno con el fin de aliviar los retos intrínsecos de estas novedosas tecnologías. La presencia de grafeno demuestra un efecto favorable sobre el rendimiento de dichos sistemas tanto en términos de densidad energética como de potencia

    Brewers’ Spent Grains‐Derived Carbon as Anode for Alkali Metal‐Ion Batteries

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    Herein, the synthesis of a nongraphitizable carbon through cost‐effective pyrolysis of a brewery waste product is reported. It is demonstrated that it is possible to realize hard carbon (HC) with structural and morphological properties from an abundant biomass source with a suitable application in energy storage devices. Resulting HC displays reversible capacities of 334, 112 , and 140 mAh g −1 after 100 cycles at 1C with high charge/discharge efficiency (>99.6%) in Li‐ion, Na‐ion, and K‐ion batteries, respectively. Thus, HC derived from brewers’ spent grains can be considered as promising materials for the realization of advanced metal‐ion batteries

    Phosphorus-Functionalized Graphene for Lithium-Ion Capacitors with Improved Power and Cyclability

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    Herein, we report an easy approach for the preparation of graphene-based materials suitable as electrodes for lithium-ion capacitors (LICs). To the best of our knowledge, this is the first time that phosphorus-functionalized graphene oxide (rGO800-P) is used as negative (battery-type) electrode in LICs technology. An activated carbon derived from the pyrolysis of graphene-carbon composite served as positive (capacitor-type) electrode. While phosphorus functionalization on the negative electrode enables fast Li+ kinetics during insertion/extraction processes, the flat-shaped morphology, large surface area and proper pore size distribution of the positive electrode enhance the double-layer formation. Full LICs optimization, oversizing the negative electrode allows operating in the extended voltage window of 1.5-4.5 V delivering high energy and power values (91 Wh kg(AM)(-1) at 145 W kg(AM)(-1) and 33 Wh kg(AM)(-1) at 26,000 W kg(AM)(-1)) without compromising the cycling performance (76 % capacitance retention after 10,000 cycles)The authors thank the European Union (Graphene Flagship, Core 3, Grant number 881603) and the Spanish Ministry of Science and Innovation (MICINN/FEDER) (RTI2018-096199-B-I00) for the financial support of this work. J.L.G.U. is very thankful to the Spanish Ministry of Education, Science and Universities (MICINN) for the FPU grant (16/03498). We also want to acknowledge the company GRAPHENEA for supplying the graphene oxide used in this wor

    Understanding enhanced charge storage of phosphorus-functionalized graphene in aqueous acidic electrolytes

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    The mechanisms behind enhanced charge storage of P-functionalized carbons are unraveled for the first time using non-porous graphene oxide treated with phosphoric acid and annealed at either 400 or 800 degrees C. The electrochemical study in 1 M H2SO4 reveals that phosphorus groups boost charge storage and electrochemical stability, with more effect for the higher annealing temperature. Annealing at 800 degrees C also leads to the material withstanding 60,000 charge-discharge cycles with no capacitance loss at 1.5 V. The improvement in the electrochemical performance is shown to be mainly governed by the change in surface chemistry comprehensively studied with NMR, FTIR and XPS characterization techniques. The collective analysis of electrochemical response and surface chemistry demonstrates that enhanced charge storage by phosphorus-functionalized graphene materials is made possible due to the following synergistic mechanisms: i) non-Faradaic charging; ii) nascent hydrogen storage in the interlayer; iii) benzoquinoneto-hydroquinone redox processes; iv) phosphate-to-phosphonate like transformation. From the practical perspective, the stored charge can be boosted due to the higher capacitance upon prior electrochemical activation in the vicinity of oxygen evolution potential and the wider usable electrochemical window enabled by phosphorus-related groups. (C) 2020 The Author(s). Published by Elsevier Ltd.The authors thank the European Union (Graphene Flagship, Core 2, Grant number 785219) and the Spanish Ministry of Science and Innovation (MICINN/FEDER) (RTI2018-096199-B-I00) for the financial support of this work. J. L. G. U. is very thankful to the Spanish Ministry of Education, Science and Universities (MICINN) for the FPU grant (16/03498). We also want to acknowledge the company GRAPHENEA for supplying the graphene oxide used in this work and Yan Zhang from CIC Energigune for collecting FTIR spectra

    Everolimus safety and efficacy for renal angiomyolipomas associated with tuberous sclerosis complex: A Spanish expanded access trial

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    Background: Renal angiomyolipomas (AML) are usual manifestations of tuberous sclerosis complex (TSC) that may cause aneurism-related haemorrhages and renal impairment. Everolimus has emerged as an alternative to surgery/embolization. We provide further insight into everolimus safety and efficacy for TSC-related AML. Methods: This was a Spanish expanded access trial including patients aged ≥18 years with TSC-related AML. They received 10 mg everolimus once daily until AML progression, unacceptable toxicity, death/withdrawal, commercialisation for TSC-related AML, or 1 year after first patient enrolment. The primary outcome was dose-limiting safety according to grade 3/4 adverse events, serious adverse events, or adverse events leading to treatment modification. Secondary outcomes included overall safety and efficacy. Results: Nineteen patients were enrolled and received everolimus for a median of 6.6 (5.3-10.9) months. Eleven (57.9 %) remained on 10 mg/day throughout the study and eight (42.1 %) required treatment modifications due to adverse events; none permanently discontinued treatment. Adverse events were overall grade 1/2 and most frequently included aphthous stomatitis/mucosal inflammation, hypercholesterolaemia/hypertriglyceridaemia, urinary tract infection, hypertension, dermatitis acneiform, and insomnia. Four (21.1 %) patients experienced grade 3 adverse events, none was grade 4, and only one (5.3 %) was serious (pneumonia). AML volume was reduced ≥30 % in 11 (57.9 %) patients and ≥50 % in 9 (47.4 %); none progressed. Right and left kidney sizes decreased in 16 and 14 patients, respectively. Conclusions: These findings support the benefit of everolimus for renal AML due to a manageable safety profile accompanied by reduced AML and kidney volumes. Trial registration: EudraCT number 2012-005397-63; date of registration 22 Nov 2012.This work was funded by Novartis Farmacéutica S.A., which was involved in study design, data analysis and interpretation, and writing of the manuscrip

    High Energy Density Lithium–Sulfur Batteries Based on Carbonaceous Two-Dimensional Additive Cathodes

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    The increasing demand for electrical energy storage makes it essential to explore alternative battery chemistries that overcome the energy-density limitations of the current state-of-the-art lithium-ion batteries. In this scenario, lithium–sulfur batteries (LSBs) stand out due to the low cost, high theoretical capacity, and sustainability of sulfur. However, this battery technology presents several intrinsic limitations that need to be addressed in order to definitively achieve its commercialization. Herein, we report the fruitfulness of three different formulations using well-selected functional carbonaceous additives for sulfur cathode development, an in-house synthesized graphene-based porous carbon (ResFArGO), and a mixture of commercially available conductive carbons (CAs), as a facile and scalable strategy for the development of high-performing LSBs. The additives clearly improve the electrochemical properties of the sulfur electrodes due to an electronic conductivity enhancement, leading to an outstanding C-rate response with a remarkable capacity of 2 mA h cm–2 at 1C and superb capacities of 4.3, 4.0, and 3.6 mA h cm–2 at C/10 for ResFArGO10, ResFArGO5, and CAs, respectively. Moreover, in the case of ResFArGO, the presence of oxygen functional groups enables the development of compact high sulfur loading cathodes (>4 mgS cm–2) with a great ability to trap the soluble lithium polysulfides. Notably, the scalability of our system was further demonstrated by the assembly of prototype pouch cells delivering excellent capacities of 90 mA h (ResFArGO10 cell) and 70 mA h (ResFArGO5 and CAs cell) at C/10.This work was funded by the European Union’s Horizon 2020 research and innovation program Graphene Flagship Core Project 3 (GrapheneCore3) under grant agreement 881603. The project was also supported by Ministerio de Ciencia, Innovación y Universidades (MCIU), Agencia Estatal de Investigación (AEI), and the European Regional Development Fund (ERDF) (RTI2018-098301-B-I00). J.C. is a beneficiary of the Predoctoral Program from the Education Department of the Basque Government. J.L.G.-U. is very thankful to the Spanish Ministry of Universities for the FPU grant (16/03498). Finally, we want to acknowledge GRAPHENEA for supplying the graphene oxide used in this work

    Usefulness of bone turnover markers as predictors of mortality risk, disease progression and skeletal-related events appearance in patients with prostate cancer with bone metastases following treatment with zoledronic acid: TUGAMO study

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    Owing to the limited validity of clinical data on the treatment of prostate cancer (PCa) and bone metastases, biochemical markers are a promising tool for predicting survival, disease progression and skeletal-related events (SREs) in these patients. The aim of this study was to evaluate the predictive capacity of biochemical markers of bone turnover for mortality risk, disease progression and SREs in patients with PCa and bone metastases undergoing treatment with zoledronic acid (ZA). Methods: This was an observational, prospective and multicenter study in which ninety-eight patients were included. Patients were treated with ZA (4mg every 4 weeks for 18 months). Data were collected at baseline and 3, 6, 9, 12, 15 and 18 months after the beginning of treatment. Serum levels of bone alkaline phosphtase (BALP), aminoterminal propeptide of procollagen type I (P1NP) and beta-isomer of carboxiterminal telopeptide of collagen I (b-CTX) were analysed at all points in the study. Data on disease progression, SREs development and survival were recorded. Results: Cox regression models with clinical data and bone markers showed that the levels of the three markers studied were predictive of survival time, with b-CTX being especially powerful, in which a lack of normalisation in visit 1 (3 months after the beginning of treatment) showed a 6.3-times more risk for death than in normalised patients. Levels of these markers were also predictive for SREs, although in this case BALP and P1NP proved to be better predictors. We did not find any relationship between bone markers and disease progression. Conclusion: In patients with PCa and bone metastases treated with ZA, b-CTX and P1NP can be considered suitable predictors for mortality risk, while BALP and P1NP are appropriate for SREs. The levels of these biomarkers 3 months after the beginning of treatment are especially importantThis study was supported by Novartis Oncology Spai

    Una perspectiva multidisciplinaria

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    Derivado de la necesidad de fomentar la investigación multidisciplinaria, la Facultad de Economía de la Universidad Autónoma del Estado de México llevó a cabo los días 8 y 9 de septiembre de 2016, el VIII Coloquio de Investigación intitulado “Desarrollo económico, regional y sustentable”. En este magno evento se presentaron 36 ponencias agrupadas en cinco mesas de trabajo: sectores productivos, crecimiento económico y mercado de trabajo; tecnología, innovación y organizaciones; desigualdad regional, pobreza y migración; economía financiera e internacional; y medio ambiente y sociedad. Del material expuesto en el VIII Coloquio, se eligieron 16 investigaciones, mismas que integran este libro. Los estudios presentados en cada uno de los subsiguientes capítulos fueron seleccionados de acuerdo a un proceso de rigurosidad científica, siendo sometidos a dictamen por pares ciegos a partir de la integración de un Comité Académico de expertos. Lo anterior con la finalidad de proporcionar al lector un material de investigación de calidad y solidez científica respecto a temas de trascendencia vinculados con los sectores productivos, la innovación, las organizaciones, la responsabilidad social, la desigualdad, la educación y el medioambiente.Consecuencia de la apertura de los mercados y los preceptos competitivos dictados por la globalización, se manifiesta la necesidad de vincular los diversos saberes provenientes de las ciencias naturales y sociales, con el fin de complementar el conocimiento y generar nuevas formas de visualizar el entorno. A raíz de ello, la investigación multidisciplinaria asume un papel cada vez más importante en los círculos académicos, empresariales y gubernamentales. En este marco, entra en desuso la visualización del individuo como un sujeto atomístico desvinculado del medio ambiente que le rodea. El objetivo de este libro es otorgar una visión multidisciplinaria al estudio de temas económicos incorporando visiones teóricas y empíricas procedentes de las ciencias sociales y naturales. La obra está compuesta por 16 capítulos agrupados en cuatro secciones. La primera parte, conglomera cinco capítulos en torno a los tópicos sectores productivos y crecimiento económico.Facultad de Economía. Universidad Autónoma del Estado de Méxic

    Boosting the Performance of Graphene Cathodes in Na–O2 Batteries by Exploiting the Multifunctional Character of Small Biomolecules

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    Graphene aerogels derived from a biomolecule‐assisted aqueous electrochemical exfoliation route are explored as cathode materials in sodium–oxygen (Na–O2) batteries. To this end, the natural nucleotide adenosine monophosphate (AMP) is used in the multiple roles of exfoliating electrolyte, aqueous dispersant, and functionalizing agent to access high quality, electrocatalytically active graphene nanosheets in colloidal suspension (bioinks). The surface phenomena occurring on the electrochemically derived graphene cathode is thoroughly studied to understand and optimize its electrochemical performance, where a cooperative effect between the nitrogen atoms and phosphates from the AMP molecules is demonstrated. Moreover, the role of the nitrogen atoms in the adenine nucleobase of AMP and short‐chain phosphate is unraveled. Significantly, the use of such cathodes with a proper amount of AMP molecules adsorbed on the graphene nanosheets delivers a discharge capacity as high as 9.6 mAh cm−2 and performs almost 100 cycles with a considerably reduced cell overpotential and a coulombic efficiency of ≈97% at high current density (0.2 mA cm−2). This study opens a path toward the development of environmentally friendly air cathodes by the use of natural nucleotides which offers a great opportunity to explore and manufacture bioinspired cathodes for metal–oxygen batteries.M.E., J.L.G.‐U., D.C., and N.O.‐V. thank the European Union (Graphene Flagship‐Core 3, Grant number 881603) and the Spanish Ministry of Science and Innovation (MICINN/FEDER) (RTI2018‐096199‐B‐I00) for the financial support of this work. J.M.M., J.I.P., and S.V.‐R. gratefully acknowledge funding by the Spanish Ministerio de Ciencia, Innovación y Universidades (MICINN), Agencia Estatal de Investigación (AEI), and the European Regional Development Fund (ERDF) through project RTI2018‐100832‐B‐I00, as well as Plan de Ciencia, Tecnología e Innovación (PCTI) 2013‐2017 del Principado de Asturias and the ERDF (project IDI/2018/000233). J.L.G.‐U. is very thankful to the Spanish Ministry of Education, Science and Universities (MICINN) for the FPU grant (16/03498)Peer reviewe
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