2,565 research outputs found
The Atopic March. A Literature Review
The atopic march is defined as the progression of atopic diseases, generally during childhood, such as atopic dermatitis, asthma, allergic rhinitis and food allergies. The main risk factors for developing these atopic diseases include genetics, aeroallergens, food allergens, latefood introduction to the infant, and living in developing countries. The immunologic contributors to this problem include the Th2 response, epigenetics, and lack of certain factors like thymic stromal lymphopoietin (TSLP) and filaggrin. As a whole, the therapeutic approach has been changing during recent years because of the discovery of new factors involved in this problem. This article explains the definition of atopic march, the immunological pathway, clinical features, epidemiology and therapeutic approaches to create a context for the broader understanding of this important condition
Dinámica del crecimiento en los municipios colombianos. 1985 - 2010
Maestría en Economía, Facultad de Ciencias Contables, Económicas y Administrativas.La presente tesis se concentra en la validación de la hipótesis de convergencia condicional y club al interior de Colombia, utilizando como unidad de análisis el municipio, y como variable de análisis el valor del impuesto de industria y comercio per cápita de 787 municipios colombianos utilizando la aplicación de técnicas de econometría espacial. Los resultados encontrados rechazan la hipótesis de convergencia condicional en la visión Barro & Sala-i-Martin (1991, 1992) en el crecimiento de los municipios colombianos, encontrando una velocidad de divergencia entre -0.47% y -0.48% para el período 1985 – 2010 de acuerdo con la técnica econométrica empleada. La evidencia encontrada a través del análisis espacial de datos, la construcción de kernels estocásticos y el uso de matrices de Markov, confirma que el crecimiento municipal colombiano muestra evidencia de convergencia tipo club. El 61% de los municipios analizados generan una renta inferior a la mitad de la renta media per cápita nacional y sólo el 22% de los municipios logran superarla. El uso de cadenas ergódicas de Markov permite comprobar que el proceso de crecimiento municipal colombiano en el largo plazo se configura como un desequilibrio estable, donde persiste un mecanismo de doble vía que genera divergencia y fortalece la polarización
Design and implementation of an ultrasonic sensor for rapid monitoring of industrial malolactic fermentation of wines
Ultrasound is an emerging technology that can be applied to monitor food processes. However, ultrasonic techniques are usually limited to research activities within a laboratory environment and they are not extensively used in industrial processes. The aim of this paper is to describe a novel ultrasonic sensor designed to monitor physical–chemical changes that occur in wines stored in industrial tanks. Essentially, the sensor consists of an ultrasonic transducer in contact with a buffer rod, mounted inside a stainless steel tube section. This structure allows the ultrasonic sensor to be directly installed in stainless steel tanks of an industrial plant. The operating principle of this design is based on the measurement of ultrasonic velocity of propagation. To test its proper operation, the sensor has been used to measure changes of concentration in aqueous samples and to monitor the progress of a malolactic fermentation of red wines in various commercial wineries. Results show the feasibility of using this sensor for monitoring malolactic fermentations in red wines placed in industrial tanks.Postprint (author's final draft
Caracterización de tejido cerebral artificial utilizando Inverse-FEM para simular indentación y comprensión
The realistic simulation of tool-tissue interactions is necessary for the development of surgical simulators and one of the key element for it realism is accurate bio-mechanical tissue models. In this paper, we determined the mechanical properties of soft tissue by minimizing the difference between experimental measurements and the analytical or simulated solution of the deformation. Then, we selected the best model parameters that fit the experimental data to simulate a bonded compression and a needle indentation with a flat-tip. We show that the inverse FEM allows accurate material property estimation. We also validated our results using multiple tool-tissue interactions over the same specimen.La simulación realista de las interacciones herramienta-tejido es necesaria para el desarrollo de simuladores quirúrgicos y uno de los elementos clave para su realismo son los modelos precisos de tejido biomecánico. En este artículo, determinamos las propiedades mecánicas del tejido blando minimizando la diferencia entre las mediciones experimentales y la solución analítica o simulada de la deformación. Luego, seleccionamos los mejores parámetros del modelo que se ajustan a los datos experimentales para simular una compresión unida y una sangría de aguja con una punta plana. Mostramos que el FEM inverso permite una estimación precisa de la propiedad del material. También validamos nuestros resultados usando múltiples interacciones herramienta-tejido sobre la misma muestra
Mapping the Mechanical Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Banded Spherulites by Nanoindentation
Nanoindentation provides clear evidence that spherulite banding can be associated with a continuous modulation of mechanical properties from the more compliant peaks to the stiffer valleys. The structural arrangement in polymer-banded spherulites has intrigued scientists for many decades, and the debate has been recently intensified with the advent of new experimental evidence. The present paper approaches this issue by exploring the local mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-ringed spherulites via nanoindentation and discussing the confidence of the results. It was found that storage modulus and hardness across the banding morphology can be described as a sequence of regular oscillations with a periodicity that exactly matches the one observed using optical and atomic force microscopy. Results are consistent with the model of regular twisting of the lamellae, with flat-on arrangement in the low regions and edge-on lamellae in the crests.The authors wish to thank the MINECO (Ministerio de Economía y Competitividad), Spain,
for funding the research reported under grants MAT2013-47898-C2-1-R (covering the costs to publish in open
access) and MAT2012-36341. Patricia Enrique-Jimenez acknowledges MINECO for a FPI (Formación Personal
Investigador) studentship.
We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)
Hysteroscopic findings and intrauterine pathology treatment in Mexican infertile women
Background: Hysteroscopy is a minimally invasive approach in gynecologic surgery and one of the main procedures performed on women undergoing fertility treatments. Intrauterine pathology negatively affects fertility by decreasing endometrial receptivity and embryo implantation success, and its prevalence has been reported between 19% and 62%. The aim of our study was to describe the hysteroscopic findings, prevalence of intrauterine pathology, the instruments used for the treatment of structural lesions in Mexican infertile women; and to compare the relationship of positive findings with the type of infertility.
Methods: This was a descriptive, cross-sectional study conducted at fertility clinic at a private hospital.
Results: We evaluated 191 hysteroscopies; the mean age of women was 35.5+3.2 years and the mean time of infertility 5.7+3.2 years. Primary infertility was the most prevalent (79.1%). In 118 cases (61.8%), uterine cavity abnormalities were diagnosed, the most frequent findings were: polyps (n=51, 26.7%), endometritis (n=30, 15.7%), fibroids (n=15, 7.6 %), synechiae (n=12, 6.5%), and müllerian anomalies (n=10, 5.3%). For structural pathology treatment, cold scissors and bipolar energy were used in 65.5% and 34.5%, respectively.
Conclusions: Overall intrauterine pathology prevalence in our study population was 61.8%. Cold scissors and bipolar energy were used for structural lesions treatment. When comparing the relationship of hysteroscopic findings, no statistically significant difference was found in the presence of positive findings, with the type of infertility.
Sistema de Gestión Integral de Residuos en una Empresa Automotriz
A medida que el mundo ha ido evolucionando, la sociedad ha ido cambiando sus esquemas de
consumo y producción, el mundo se ha tornado más productivo para sostener la demanda de la
sociedad actual y a su vez, los productos y residuos han aumentado su ciclo de vida, se han
tornado cada vez más complejos por su composición, antes los residuos era más de composición
orgánica, hoy es más compleja lo que trae como consecuencia un aumento en los volúmenes
siendo una preocupación la gestión de residuos a nivel mundial, haciéndose un tema de gran
preocupación no sólo para el gobierno, sino también para las organizaciones no gubernamentales.
La industria automotriz a nivel nacional, es el sector productivo que ocupa el tercer lugar en
generación de residuos peligrosos por ello, se implementa un Sistema de Gestión Integral de
Residuos, realizando un diagrama de proceso desde el inicio del proceso, analizando entradas y
salidas a las entradas de la materia prima haciendo compras razonables con el enfoque de evitar que
los residuos sean generados, hacer comprar más amigables al ambiente con el menor impacto
ambiental, con menos empaque, con el menor riesgo posible al ambiente y al personal involucrado,
por ello, como parte de la mejora continua, explícito en la norma ISO 14001:2004 en su elemento
4.1, se hace un análisis de entradas y salidas en una empresa automotriz, desde que inicia el
proceso hasta que termina para determinar, categorizar y cuantificar los residuos peligrosos y de
manejo especial realizando un sistema de gestión integral con un enfoque de prevención,
minimización, reúso, reciclo, tratamiento, coprocesamiento o conexión a otro proceso, dejando al
último el confinamiento que vaya más allá de un simple cumplimiento legal donde no solo lo
ambiental se vea favorecido si no también lo económico y lo social
A case–control study to assess the effectiveness of pertussis vaccination during pregnancy on newborns, Valencian community, Spain, 1 March 2015 to 29 February 2016
In the Valencian Community (Spain), the programme of maternal pertussis vaccination during pregnancy started in January 2015. The objective of this study was to estimate in this region the vaccine effectiveness (VE) in protecting newborns against laboratory-confirmed pertussis infection. A matched case–control study was undertaken in the period between 1 March 2015 and 29 February 2016. Twenty-two cases and 66 controls (+/− 15 days of age difference) were included in the study. Cases were non-vaccinated infants < 3 months of age at disease onset testing positive for pertussis by real-time PCR. For every case three unvaccinated controls were selected. Odds ratios (OR) were calculated by multiple conditional logistic regression for association between maternal vaccination and infant pertussis. Other children in the household, as well as mother- and environmental covariates were taken into account. The VE was calculated as 1 − OR. Mothers of five cases (23%) and of 41 controls (62%) were vaccinated during pregnancy. The adjusted VE was 90.9% (95% confidence interval (CI): 56.6 to 98.1). The only covariate in the final model was breastfeeding (protective effect). Our study provides evidence in favour of pertussis vaccination programmes for pregnant women in order to prevent whooping cough in infants aged less than 3 months
Eco-Sustainable housing development for vulnerable population
El trabajo consiste en el montaje de un módulo habitacional ecosostenible para sectores vulnerables (en el caso de
este proyecto: Fundación “Kyrios”, centro de restauración), fabricado en plástico y tetrapack reciclado, proveniente
de residuos en procesos de empaque de diferentes empresas; con instalación de sistemas ecoeficientes (panel
fotovoltaico, y colector solar) para suplir demandas energéticas eléctrica y térmica respectivamente. Se realizan
pruebas de resistencia mecánica, conductividad térmica, acústica y permeabilidad del material de construcción que
garantizan las condiciones de habitabilidad adecuadas. Abstract
The project consists of the installation of an environmentally sustainable housing module (In this project, for the
“Kyrios” Foundation, Rehabilitation Center): the module was built with waste plastic materials discarded from
industrial packaging processes. Different sustainable systems were installed (photovoltaic system, solar collector)
to satisfy electricity and thermal energy demands. In order to satisfy the conditions of housing, different tests
were performed on the construction material such as mechanical resistance, thermal and acoustic conductivity and
permeability
Carbones colombianos: clasificación y caracterización termoquímica para aplicaciones energéticas
ResumenLa relación reservas/producción de carbón en Colombia ronda los 91 años. Para aprovechar tal disponibilidad del carbón mediante tecnologías de alta eficiencia, es necesario contar con la adecuada caracterización de los diferentes carbones. En este trabajo se analizaron 10 muestras de carbones colombianos con diferentes rangos y calidad, procedentes de diferentes locaciones geográficas. Cada muestra se caracterizó según su análisis próximo, análisis último, análisis termogravimétrico (TGA) y poder calorífico. Se estableció el rango o calidad de cada muestra según diferentes métodos estandarizados, incluyendo normas ASTM, diagramas de Van Kleveler, método gráfico de Parr y la norma ISO 11760-2005. Adicionalmente se determinó la reactividad de las muestras a través de análisisTGA y análisis térmico diferencial (DTG). Se encontró que los carbones de mayor rango o calidad no necesariamente resultan ser los más reactivos para aplicaciones energéticas, ya que a mayor proporciónde carbono fijo, la liberación de material volátil tiende a ser más lenta, disminuyendo su capacidad de uso y transformación en procesos termoquímicos. Palabras clave: carbones colombianos, análisis próximo, análisis último, reactividad, rango, aprovechamiento energético. Colombian coals: classification and thermochemical characterization for energy applications Abstract Colombian coal reserves/production ratio is around 91 years. The challenge is to exploit the availability of coal in Colombia by means of higher efficiency technologies, it is necessary to characterize the different coals properly. In this work ten Colombian samples of coal with different rank and quality were analyzed. The samples are from different regions around the country. Each sample was characterized according to proximate and ultimate analysis, as well as thermogravimetric analysis and heating value. For each coal sample was assessed its rank or quality according to different standardized methods, i.e., ASTM standard, Van Kleveler diagram, Parr method and ISO 11760-2005 standard. Moreover, the reactivity of each sample was determined by means of thermogravimetric and its differential thermal analyses. It was found that the coals with the higher rank are not necessarily the more reactive fuels for energy use. This is due to the coals, with higher fixed carbon, release the volatile matter slowly; therefore, its use capacity and its thermochemical transformation decreases. Keywords: colombian coals, proximate and ultimate analysis, reactivity, coal Rank, energy use. Carvões colombianos: classificação e caracterização para aplicações de energia termoquímica ResumoA relação reservas / produção de carvão na Colômbia é de cerca de 91 anos. Procurando explorar a disponibilidade de carvão na Colômbia, por meio de tecnologias de eficiência mais elevados, é necessário ter a caracterização adequada dos diferentes carvões. Neste trabalho foram analisadas dez amostras de carvão da Colômbia com diferentes categoria e qualidade. As amostras são provenientes de diferentes regiões do país. Cada amostra foi caracterizada de acordo com a análise imediata e definitiva, bem como a análise termogravimétrica (TGA) e valor calórico. Para cada amostra de carvão foi avaliada a sua categoria ou qualidade de acordo com diferentes métodos padrão, incluindo ASTM, diagramas Van Kleveler, método Parr e padrão ISO 11760-2005. Além disso, a reatividade de cada amostra foi determinada utilizando TGA e suas análises térmicas diferenciais. Verificou-se que as brasas com o posto mais alto não são necessariamente os combustíveis mais reativas para aplicações de energia, porque com maior proporção de carbono fixo, a matéria volátil que é liberado mais lentamente, portanto, a sua capacidade de uso e sua transformação termoquímica tende a ser mais lenta. Palabras-chave: carvão da Colômbia, análise imediata e definitiva, reatividade, carvão rank, utilização de energia. Cita: Barrera Zapata R, Perez Bayer JF, Salazar Jiménez C. Carbones colombianos: clasificación y caracterización termoquímica para aplicaciones energéticas. rev.ion. 2014;27(2):43-54
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