80 research outputs found

    Diseño y control digital de un convertidor elevador entrelazado para sistemas de carga/descarga de baterías

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    According to the literature, battery ripple current is one of the phenomena that most significantly affect the state of health of batteries. Therefore, this paper presents a methodology to design a digital control in order to reduce such ripple current, which is injected by means of converters that process the charge and discharge energy. The strategy was designed for and implemented in an interlaced converter. The implemented methodology is presented in four stages: (i) modelling the battery-converter-charge system; (ii) designing the digital control based on the model; (iii) designing the practical implementation, where the instrumentation and implementation stage is presented using an embedded device; and (iv) practical validation of the operation of the strategy and the reduction of battery ripple current. The methodology presented here produced a correct performance of the digital control, fulfilling the design parameters of different operation modes and reducing the ripple current in the battery between 50 and 65%. This reduction protects the battery’s useful life and the sources or loads connected to the system. Additionally, it allows the state-of-charge and health estimation algorithms to increase their accuracy, which leads to an improvement in maintenance protocols and the planning of element replacement. Este trabajo presenta la metodología de diseño de un control digital para reducir el rizado en la corriente que se inyecta a la batería por medio de los convertidores que procesan la energía de carga y descarga, el cual es uno de los parámetros indicados en la literatura que disminuyen el tiempo de vida de las baterías. Este trabajo tiene como alcance mostrar el procedimiento de diseño e implementación de la estrategia propuesta sobre un convertidor entrelazado. La metodología implementada se presenta por medio de cuatro etapas (i) modelado del sistema batería-convertidor-carga, (ii) diseño de control digital basado en el modelo, (iii) diseño de la plataforma práctica donde se presenta la etapa de instrumentación e implementación utilizando un dispositivo embebido y (iv) la validación práctica del funcionamiento de la estrategia presentada y la disminución del rizado inyectado en la batería. Por medio de la metodología presentada se logra evidenciar el correcto desempeño del control digital cumpliendo los parámetros de diseño para diferentes modos de operación de carga de la batería y reduciendo el rizado de corriente en la batería entre un 50 % a 65 %. Esta reducción protege la vida útil de la batería y de las fuentes o cargas conectadas al sistema. Adicionalmente, permite que los algoritmos de estimación de estado de carga y estado de salud incrementen su precisión, lo que conlleva a una mejora en los protocolos de mantenimiento y planificación de reemplazo de los elementos

    Physico-chemical characterization and antioxidant capacity of the colombian berry (Vaccinium meridionale Swartz) with a high-polyphenol content: potential effects in people with metabolic syndrome

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    ABSTRACT: Colombian berry (agraz) has demonstrated a high antioxidant content in vitro. In the present study, it was elaborated and characterized an agraz nectar, designed a placebo with similar physicochemical and sensorial characteristics of the agraz nectar, but without polyphenols; and evaluated their antioxidant capacity both in vitro and in vivo in adults with cardiovascular risk factors. The polyphenolic concentration of the agraz nectar and its antioxidant capacity was superior than other reported for this fruit. A high content of total cyanidins was observed in the freeze-dried agraz, but not delphinin was detected by HPLC. For the intervention study, sixty-six subjects, with at least three cardiometabolic risk factors, consumed agraz nectar or placebo daily during 4 weeks each, separated by a 4-week washout period. Total phenol concentration and antioxidant capacity in the participants’ serum were not statistically different after consuming agraz nectar and placebo. However, women increased significantly their serum DPPH scavenging capacity after consuming agraz nectar, compared to placebo. This is one of the first studies showing data about the effects of this colombian berry on the antioxidant capacity in people with metabolic syndrome

    Determination of reference biological intervals in a hematology analyzer BC-5000 of the Microbiology School of the University of Antioquia, Medellin 2017

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    Introduction: The adult hemogram values can vary according factors such as ethnic origin, age, sex and level above the sea, whereby it is essential to know the biological intervals associated to our own population. Therefore, the objective of our study was to determine biological reference intervals (BRI) for adults with the hematological equipment BC-5000. Methods: This is a transversal descriptive study with 111 blood bank donors from Medellín, between 18 and 62 years old. Hemogram, C reactive protein and ferritin were done. The BRI were calculated according to the recommendations of the International Federation of Clinical Chemistry (IFCC), with the formula X ± (DS *1, 96). BRI comparison according sex was carried out with the t-student test. Results: Calculated BRI by X ± (DS * 1, 96) formula, showed statistically significant differences (P < 0, 05) between men and women for count in most of the parameters. Higher statistical means were obtain in women for the count of leukocytes and platelets, absolute counts of some white cells, VPN y PCT. Discussion: The presence of androgens in the male sex, inductors of the erythropoiesis system, as well as the estrogens and menstrual period, suppressor of this system, can explain the lower values in the female erythrocyte count, the hemoglobin, hematocrit and red cell lower ranges. The high estrogen and interleukins 6 and 1 loads in women, drive the extended half-life of some cells like lymphocytes, that can explain the difference in leucocyte count found in the present study

    Menarche, pregnancies, and breastfeeding do not modify long-term prognosis in multiple sclerosis

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    ObjectiveTo investigate the effect of menarche, pregnancies, and breastfeeding on the risk of developing multiple sclerosis (MS) and disability accrual using a multivariate approach based on a large prospective cohort of patients with clinically isolated syndrome (CIS).MethodsA cross-sectional survey of the reproductive information of female participants in a CIS cohort was performed. We examined the relationship of age at menarche with the risk of clinically definite MS (CDMS), McDonald 2010 MS, and Expanded Disability Status Scale (EDSS) 3.0 and 6.0. The effect of pregnancy (before and after CIS) and breastfeeding in the risk of CDMS, McDonald 2010 MS, and EDSS 3.0 was also examined. Univariate and multivariate analyses were performed and findings were confirmed using sensitivity analyses and a propensity score model.ResultsThe data of 501 female participants were collected. Age at menarche did not correlate with age at CIS and was not associated with the risk of CDMS or EDSS 3.0 or 6.0. Pregnancy before CIS was protective for CDMS in the univariate analysis, but the effect was lost in the multivariate model and did not modify the risk of EDSS 3.0. Pregnancy after CIS was protective for both outcomes in univariate and multivariate analyses when pregnancy was considered a baseline variable, but the protective effect disappeared when analyzed as a time-dependent event. Breastfeeding did not modify the risk for the 3 outcomes.ConclusionsThese results demonstrate that menarche, pregnancies, and breastfeeding did not substantially modify the risk of CDMS or disability accrual using a multivariable and time-dependent approach

    The long-term outcomes of CIS patients in the Barcelona inception cohort : Looking back to recognize aggressive MS

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    Altres ajuts: This study has been funded by European Regional Development Fund and co-funded by Instituto Carlos III. It has also received support by a grant from Genzyme foundation (GENZYME-2015-01) granted to M.T. and from the 'Red Española de Esclerosis Múltiple (REEM)', which is sponsored by FIS, the Instituto de Salud Carlos III, the Ministry of Economy and Competitiveness in Spain, and the 'Ajuts per donar Suport als Grups de Recerca de Catalunya', which is sponsored by the 'Agència de Gestió d'Ajuts Universitaris i de Recerca' (AGAUR) of the Generalitat de Catalunya in Spain.To explore the long-term outcomes of patients with clinically isolated syndromes from the Barcelona cohort. We selected patients with a follow-up longer than 10 years to (1) estimate the risks of multiple sclerosis (MS) and disability accumulation according to the baseline number of T2 lesions and to compare treated versus untreated patients and early versus delayed treatment, and (2) to study baseline features of patients with aggressive MS (Expanded Disability Status Scale (EDSS) ⩾6.0 at 10 years). In all, 401 patients were included (mean follow-up of 14.4 (standard deviation of 2.9) years). A higher number of T2 lesions was associated with an earlier MS diagnosis and an earlier risk of irreversible disability. Early treatment was associated with a decreased risk of EDSS of 3.0: adjusted hazard ratio = 0.4, 95% confidence interval = (0.2, 0.7). Patients with aggressive MS differed in their baseline brain magnetic resonance images: The median (interquartile range) number of T2 lesions and contrast-enhancing lesions (CEL) was 71 (28-95) versus 7 (1-19) and 3 (1-24) versus 0 (0-1), respectively. The cut-offs that better classified patients with aggressive MS were 20 for T2 lesions and 2 for CEL. Although MS natural history is changing, a high lesion load at onset is helpful to identify patients at risk of presenting an aggressive MS

    Monitorización y seguimiento del esfuerzo realizado por los estudiantes y de su asistencia a actividades presenciales

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    Este artículo documenta el planteamiento, la metodología y los primeros resultados de un plan de monitorización detallada del esfuerzo y de asistencia a actividades presenciales por parte de los estudiantes de las titulaciones ofertadas por la Escuela Técnica Superior de Ingenieros Navales de la Universidad Politécnica de Madrid durante el segundo cuatrimestre del curso 2011-2012. Se ha establecido un sistema mecánico de recogida de datos de esfuerzo por parte de los estudiantes utilizando una hoja tipo test especialmente configurada al efecto. Se pasa una hoja en todas y cada una de las actividades presenciales realizadas y en la hoja se solicita información sobre el trabajo "fuera de clase". Se documenta en este artículo cómo se ha estructurado esa hoja, qué tipo de datos se recogen, cómo se tratan mediante una base de datos creada al efecto, qué tipo de análisis se puede realizar y qué resultados preliminares obtenemos de dichos análisis

    Protection of Spanish Ibex (Capra pyrenaica) against Bluetongue Virus Serotypes 1 and 8 in a Subclinical Experimental Infection

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    Many wild ruminants such as Spanish ibex (Capra pyrenaica) are susceptible to Bluetongue virus (BTV) infection, which causes disease mainly in domestic sheep and cattle. Outbreaks involving either BTV serotypes 1 (BTV-1) and 8 (BTV-8) are currently challenging Europe. Inclusion of wildlife vaccination among BTV control measures should be considered in certain species. In the present study, four out of fifteen seronegative Spanish ibexes were immunized with a single dose of inactivated vaccine against BTV-1, four against BTV-8 and seven ibexes were non vaccinated controls. Seven ibexes (four vaccinated and three controls) were inoculated with each BTV serotype. Antibody and IFN-gamma responses were evaluated until 28 days after inoculation (dpi). The vaccinated ibexes showed significant (P<0.05) neutralizing antibody levels after vaccination compared to non vaccinated ibexes. The non vaccinated ibexes remained seronegative until challenge and showed neutralizing antibodies from 7 dpi. BTV RNA was detected in the blood of non vaccinated ibexes from 2 to the end of the study (28 dpi) and in target tissue samples obtained at necropsy (8 and 28 dpi). BTV-1 was successfully isolated on cell culture from blood and target tissues of non vaccinated ibexes. Clinical signs were unapparent and no gross lesions were found at necropsy. Our results show for the first time that Spanish ibex is susceptible and asymptomatic to BTV infection and also that a single dose of vaccine prevents viraemia against BTV-1 and BTV-8 replication

    The Caldera. No. 15

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    “No existe gran talento sin gran voluntad”. Honoré de Balzac. Desde la inteligencia emocional se distinguen una serie de cualidades, de aptitudes y de características que diferencian a un ser humano de otro y que nos permiten hablar de los determinados talentos que cada uno de nosotros posee. En nuestra institución, precisamente, existe un nutrido número de niños y de jóvenes talentosos en diferentes campos, a saber: La música, el teatro, la danza, el canto, los deportes, la escritura, la pintura, el diseño y, por supuesto, a nivel académico; personas sensibles al arte y a sus diferentes manifestaciones porque poseen un talento intrínseco que les permite destacarse en el medio en donde interactúan. En esta edición de “La Caldera” se pretende continuar con la labor de seguir destacando, mostrando, promoviendo algunos de los talentosos estudiantes que hacen parte de nuestra Institución. La edición también tiene como meta hacer la invitación a aquellos talentos aprendidos o innatos, pero ocultos, para que compartan con nuestra familia caldista sus dones. Es así como la institución privilegia diferentes espacios institucionales que, años tras año, han ido consolidándose como la muestra de talentos caldistas, en donde conocemos, valoramos, apreciamos y disfrutamos, precisamente, de las destrezas, de las habilidades que tienen nuestros educandos. Hagamos parte activa de estos espacios porque en la medida en la que nos involucremos, en esa medida, nuestra Institución seguirá creciendo y destacándose como una de las mejores a nivel regional y nacional.Entrevista a: William Ospina; Por: Lina maría Beltrán…04 El infinito Océano de la paz; Por: María Camila Escobar y Nicolás Espinel Martínez…05 Homenaje a Gabriel García Márquez; Por: Gisela Afanador…10 Dibujando sueños; Por: Lina maría Beltrán…14 A través de los ojos de Camila; Por: Valentina Vega…16 Expresiones Artísticas…17"There is no great talent without great will." Honoré de Balzac. From emotional intelligence, a series of qualities, aptitudes and characteristics are distinguished that differentiate one human being from another and that allow us to talk about the specific talents that each of us possesses. In our institution, precisely, there is a large number of talented children and young people in different fields, namely: music, theater, dance, singing, sports, writing, painting, design and, of course , at the academic level; people who are sensitive to art and its different manifestations because they have an intrinsic talent that allows them to stand out in the environment where they interact. In this edition of "La Caldera" it is intended to continue with the work of continuing to stand out, showing, promoting some of the talented students that are part of our Institution. The edition also aims to invite those talents learned or innate, but hidden, to share their gifts with our Caldista family. This is how the institution privileges different institutional spaces that, year after year, have been consolidated as the sample of Caldista talents, where we know, value, appreciate and enjoy, precisely, the skills, the abilities that our students have. Let's take an active part in these spaces because to the extent that we get involved, to that extent, our Institution will continue to grow and stand out as one of the best at the regional and national level

    Management of a caseous lymphadenitis outbreak in a new Iberian ibex (Capra pyrenaica) stock reservoir

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    Background: In 2010, an Iberian ibex (Capra pyrenaica hispanica) stock reservoir was established for conservation purposes in north-eastern Spain. Eighteen ibexes were captured in the wild and housed in a 17 hectare enclosure. Once in captivity, a caseous lymphadenitis (CLA) outbreak occurred and ibex handlings were carried out at six-month intervals between 2010 and 2013 to perform health examinations and sampling. Treatment with a bacterin-based autovaccine and penicillin G benzatine was added during the third and subsequent handlings, when infection by Corynebacterium pseudotuberculosis was confirmed. Changes in lesion score, serum anti-C. pseudotuberculosis antibodies and haematological parameters were analyzed to assess captivity effects, disease emergence and treatment efficacy. Serum acute phase proteins (APP) Haptoglobin (Hp), Amyloid A (SAA) and Acid Soluble Glycoprotein (ASG) concentrations were also determined to evaluate their usefulness as indicators of clinical status.Once in captivity, 12 out of 14 ibexes (85.7%) seroconverted, preceding the emergence of clinical signs; moreover, TP, WBC, eosinophil and platelet cell counts increased while monocyte and basophil cell counts decreased. After treatment, casualties and fistulas disappeared and both packed cell volume (PCV) and haemoglobin concentration significantly increased. Hp, SAA and ASG values were under the limit of detection or showed no significant differences. Conclusions: A role for captivity in contagion rate is suggested by the increase in antibody levels against C. pseudotuberculosis and the emergence of clinical signs. Although boosted by captivity, this is the first report of an outbreak of caseous lymphadenitis displaying high morbidity and mortality in wild ungulates. Treatment consisting of both vaccination and antibiotic therapy seemed to prevent mortality and alleviate disease severity, but was not reflected in the humoural response. Haematology and APP were not useful indicators in our study, perhaps due to the sampling frequency. Presumably endemic and irrelevant in the wild, this common disease of domestic small ruminants is complicating conservation efforts for the Iberian ibex in north-eastern Spain
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