215 research outputs found

    Arteriolopatía calcificante urémica, reporte de un caso tratado con tiosulfato de sodio

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    We describe a case of calcific uremic arteriolopathyinitially associated with skin lesions within the context of a patient with chronic kidney disease on automated peritoneal dialysis therapy. Among the most relevant findings, the patient hadhyperphosphatemia, normocalcemia and severe hyperparathyroidism without nodular hyperplasia. Clinical improvement with multimodal management of enhancement in dialysis therapy and intravenous sodium thiosulfate is highlighted. Calciphylaxis is a disorder that has a high morbidity and mortality, secondary to sepsis. It occurs more frequently in patients with chronic renal failure who are on hemodialysis. It is characterized by systemic medial calcification of the arterioles, triggering ischemia and subcutaneous necrosis of skin and soft tissues. Histopathological evaluation helps to confirm the diagnosis.Describimos un caso de arteriolopatía calcificante urémica asociada,  inicialmente, a lesiones cutáneas,en unpaciente con insuficiencia renal crónica, en terapia de diálisis peritoneal automatizada, como hallazgos másrelevantes presentaba hiperfosfatemia, normocalcemia e hiperparatiroidismo severo sin hiperplasia nodular.Se destaca la mejoría clínica con manejo multimodal de intensificación en la terapia dialítica y tiosulfato desodio intravenoso.La calcifilaxis es un trastorno que debuta con alta morbilidad ymortalidad, secundaria a sepsis, ocurre con mayor frecuencia en pacientes con insuficiencia renal crónica que se encuentran en hemodiálisis. Se caracteriza por calcificación sistémica en la media de las arteriolas, desencadenándose isquemia y necrosis subcutánea de piel y tejidos blandos. La evaluación histopatológica ayuda a confirmar el diagnóstico

    Solid particles formation from solutions, an intellectual and industrial meeting point and challenge

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    En aquest article presentem un recull d'experiències i idees sobre el problema de la formació de partícules sòlides nanomètriques i micromètriques a partir d'una solució. Presentem l'estat de la qüestió, alguns avanços en tècniques de precipitació, una descripció dels mecanismes de formació de partícules a partir d'una solució, amb una anàlisi de la influència de l'energia superficial formada en el curs de la nucleació sobre el procés d'agregació de nuclis. Es presenta un model d'agregació de partícules basat en la influència de les impureses.In this paper we will attempt to summarize a number of experiences and ideas concerning the problem of the formation of nanometric and micrometric solid particles from solutions. We will present the scope of the problem, some new advanced in techniques to produce and control the formation of solid particles, a description of a number of formation mechanisms of particles from solution, together with an analysis of the influence of the surface energy created in the nucleation process on the aggregation behavior of the nuclei formed. A new heuristic model on the aggregation mechanisms of particles, based on the action of impurities is proposed

    Formation Mechanism of Maghemite Nanoflowers Synthesized by a Polyol-Mediated Process

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    Magnetic nanoparticles are being developed as structural and functional materials for use in diverse areas, including biomedical applications. Here, we report the synthesis of maghemite (γ-Fe<sub>2</sub>O<sub>3</sub>) nanoparticles with distinct morphologies: single-core and multicore, including hollow spheres and nanoflowers, prepared by the polyol process. We have used sodium acetate to control the nucleation and assembly process to obtain the different particle morphologies. Moreover, from samples obtained at different time steps during the synthesis, we have elucidated the formation mechanism of the nanoflowers: the initial phases of the reaction present a lepidocrocite (γ-FeOOH) structure, which suffers a fast dehydroxylation, transforming to an intermediate “undescribed” phase, possibly a partly dehydroxylated lepidocrocite, which after some incubation time evolves to maghemite nanoflowers. Once the nanoflowers have been formed, a crystallization process takes place, where the γ-Fe<sub>2</sub>O<sub>3</sub> crystallites within the nanoflowers grow in size (from ∼11 to 23 nm), but the particle size of the flower remains essentially unchanged (∼60 nm). Samples with different morphologies were coated with citric acid and their heating capacity in an alternating magnetic field was evaluated. We observe that nanoflowers with large cores (23 nm, controlled by annealing) densely packed (tuned by low NaAc concentration) offer 5 times enhanced heating capacity compared to that of the nanoflowers with smaller core sizes (15 nm), 4 times enhanced heating effect compared to that of the hollow spheres, and 1.5 times enhanced heating effect compared to that of single-core nanoparticles (36 nm) used in this work

    Biology, incidence and host susceptibility of Pineus boerneri (Hemiptera : Adelgidae) in Colombian pine plantations

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    Adelgids (Hemiptera) in the genus Pineus have been reported as introduced insect pests causing serious losses to Pinus plantations worldwide. In 2008, Pineus boerneri was recorded for the first time in Colombia, with infestations noted on Pinus kesiya, P. tecunumanii, P. maximinoi and P. oocarpa. The lack of information on this insect in Colombia prompted investigations of its life cycle and infestation levels as well as host susceptibility of the main Pinus species planted in Colombia. In addition, the possibility of using a Ceraeochrysa species, an already established predator of adelgids in Colombia for biological control, was considered. Results showed that P. boerneri in Colombia has an anholocyclic life cycle comprised of four instars with a complete duration between 49 and 97 days. Infestations were higher in the middle and upper part of trees. Pinus kesiya and P. maximinoi had the highest levels of susceptibility in field as well as in greenhouse trials. A survey of naturally infested trees showed P. tecunumanii to be moderately susceptible while P. patula and P. oocarpa had low levels of susceptibility in a greenhouse trial but were not susceptible in the field. Investigations considering the impact of predation of Ceraeochrysa species showed a high predation rate of up to 140 P. boerneri consumed per day by a single Ceraeochrysa individual. Other predators of P. boerneri were recorded but were not sufficiently common to warrant detailed study.Smurfit Kappa Cartón de Colombia and the National Research Foundation (NRF) of South Africa.http://www.tandfonline.com/loi/tsfs20hb201

    Formation of the University Faculty in Methodological Stategies to Incorporation of E-Learning in European Space of Higher Education

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    El documento que presentamos, es una síntesis de una propuesta que presentamos al Ministerio de Educación español, y se acoge a la línea de trabajo sobre «el proceso de aprendizaje en el marco del EEES: estrategias universitarias», centrándonos más concretamente en el desarrollo de nuevas metodologías docentes y del evaluación del aprendizaje así como en el análisis y creación de estrategias para la docencia universitaria orientadas al desarrollo del aprendizaje electrónico.The document that present, is a synthesis of a proposal that present to Department of Spanish Education, and is received to the line of work on the «process of learning in Europe Space for Higher Education: university strategies», centering us more concretely in the development educational of new methodologies and of the evaluation of the learning as well as in the analysis and creation of strategies for the university teaching oriented toward development of the electronic learning

    Estudio físico, químico y microestructural de geopolímeros base ceniza volante

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    En este trabajo se analizó el comportamiento físico, químico y microestructural de la ceniza volante activada alcalinamente. Para ello fueron utilizados diferentes tamaños de partícula de ceniza volante (CV), obtenidos por molienda manual, mezcladas con NaOH y curadas durante 7, 14 y 28 días. Las técnicas de caracterización utilizadas fueron: TGA, FTIR, MEB, adsorción física de gases y pruebas de resistencia a compresión, además del software NIVision Assistant. Los resultados muestran que la disminución de tamaño de partículas, favoreció la geopolimerización del gel N-A-S-H y mejoró las propiedades cementantes en los geopolímeros, logrando resistencias a compresión hasta de 23 MPa, por otro lado, se indica mediante análisis de imagen, que los porcentajes de porosidad en cada uno de los morteros evaluados disminuyen conforme se alejan de la zona de transición interfacial (ZTI), los cuales se corroboran con los resultados de porosimetría. (ANGLÈS) In this paper was analyzed the physical, chemical and microstructural behavior of alkali activated fly ash. This comparison was used with different particle sizes of fly ash (CV), obtained by manual milling, mixed with NaOH and cured for 7, 14 and 28 days. The characterization techniques used: TGA, FTIR, SEM, physical adsorption of gases and compressive strength tests, as well NIVision Assistant software. The results show that decreasing particle size favored NASH gel Geopolymerization and improved cementitious properties in geopolymer, achieving compressive strengths up to 23 MPa. On the other hand, indicated by image analysis, the percentages of porosity in each of the mortars evaluated decrease as they move away from the interfacial transition zone (ZTI), these results are corroborated by porosimetry method.Peer ReviewedPostprint (published version

    Regeneración de campus para la creación de un laboratorio vivo de sostenibilidad ("living lab") en el Campus de Excelencia Internacional de Moncloa

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    La Universidad Politécnica de Madrid (UPM) a través de su Centro de Innovación en Tecnología para el Desarrollo Humano (itdUPM) está propiciando la generación de conciencia, conocimiento y soluciones innovadoras que contribuyen al cumplimiento de los Objetivos de Desarrollo Sostenible a través de un edificio que sirve como laboratorio de prueba para nuevas tecnologías verdes y como plataforma de ideación colaborativa y activación social

    Radar on RAIA: High frequency radars in the RAIA Observatory

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    The RADAR ON RAIA project aims to update and extend beyond the Galician border the High Frequency (HF) radar network that has been operating since 2011 in the framework of the RAIA Observatory. The Project is allowing the establishment of a cross-border collaboration beyond the physical infrastructure itself, developing a sharing strategy of maintenance procedures, validation and data processing on both sides of the border, as well as an easy and public access to all the information. In addition, new products are being developed to exploit the potential of the HF radar technology.Peer Reviewe
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