Degradação da vitamina C em um produto de manga (Mangifera indica L.) e lactisoro

This study aimed to determine the kinetics of vitamin C degradation in a product made from mango pulp (Mangifera indica L.) and whey protein powder, in order to determine the effect of temperature on its conservation and further evaluate the behavior of the L*, a*, b* and the total color difference (ΔE) in the powder product. Vitamin C was determined by the aoac 967.21/90 method using 2,6-dichlorophenol indophenol, and the color was quantified with a HunterLab Color Flex EZ colorimeter. Vitamin C showed greater stability in the powder product stored at 4 °C with a concentration at the end of the eighth sampling week of 13.94 ± 1.2 mg/10 0 g-1 sample and showing a first order degradation kinetics with k1 values of 0.014 and 0.041 mg/100 g/week at temperatures of 4 °C and 28 °C, respec-tively. The greatest variations in color occurred in samples stored at 28 °C, indicating the influence of the temperature change on the product compo-nents. In addition, L*, a* and b* parameters were less affected under storage temperature of 4 °C, and their values correspond to a second degree polynomial.Esta investigación buscó determinar la cinética de degradación de la vitamina C en un producto en polvo elaborado a base de pulpa de mango (Mangifera indica L. var. Hilacha) y lactosuero, con el fin de conocer el efecto de la temperatura en su conservación y además evaluar el comportamiento de los parámetros L*, a*, b* y la diferencia total del color (ΔE) en el producto. La vitamina C se determinó mediante el método aoac 967.21/90, con 2,6-diclorofenol indofenol; mientras que el color se cuantificó con un colorímetro Color Flex EZ marca HunterLab. La vitamina C exhibió mayor estabilidad en el producto en polvo almacenado a una temperatura de 4 °C, con una concentración (al término de la octava semana de muestreo) de 13,94 ± 1,2 mg/100 g por muestra, presentando una cinética de degradación de primer orden con valores de k1 de 0,014 y 0,041 mg/100 g/por semana para las temperaturas de 4 °C y 28 °C, respectivamente. Las mayores variaciones en el color se dieron en las muestras almacenadas a 28 °C, lo cual indica la influencia de la temperatura en el cambio de los componentes del producto. Los parámetros L*, a* y b* se vieron menos afectados a la temperatura de conservación de 4 °C y sus valores se ajustaron a un polinomio de segundo orden.Esta pesquisa procurou determinar a cinética de degradação da vitamina C em um produto em pó elaborado a base de polpa de manga (Mangifera indica L. var. Hilacha) e lactisoro, com o fim de conhecer o efeito da temperatura na sua conservação e ademais avaliar o comportamento dos parâmetros L*, a*, b* e a diferença total da cor (ΔE) no produto. A vitamina C determinou-se mediante o método aoac 967.21/90, com 2,6-diclorofenol indofe-nol; enquanto que a cor se quantificou com um colorímetro cor Flex EZ marca HunterLab. A vitamina C exibiu maior estabilidade no produto em pó armazenado a uma temperatura de 4 °C, com uma concentração (ao término da oitava semana de amostragem) de 13,94 ± 1,2 mg/100 g por amostra, presentando uma cinética de degra-dação de primeira ordem com valores de k1de 0,014 e 0,041 mg/100 g/por semana para as temperaturas de 4 °C e 28 °C, respectivamente. As maiores variações na cor deram-se nas amostras armazenadas a 28 °C, o qual indica a influência da temperatura na mudança dos componentes do produto. Os parâmetros L*, a* e b* viram-se menos afetados à temperatura de conservação de 4 °C e os seus valores se ajustaram a um polinômio de segunda ordem

Drying kinetics of two yam (dioscorea alata) varieties

The aim of this research was the evaluation of the kinetics and the drying conditions, at laboratory scale, of two yam varieties (D. alata 9506-021 and 9506-027) from the germplasm bank of the University of Cordoba (Colombia). Two geometries (circular and square) were used for the study; the air temperature ranged from 40 to 70 °C and the air speed was 0.7 m s-1. The experimental data were fitted appropriately to Fick, Page, and Logarithmic models. Mass transfer of the yam slices was described by using Fick’s diffusion model, which was the best fitted model. Drying occurred mainly in the decline phase. Arrhenius described properly the dependency of the moisture diffusivity with temperature. Among the temperature range evaluated, moisture diffusivities varied from 1.70 x 10-9 to 6.84 x 10-10 m2/s and 1.33 x 10-9 to 6.30 x 10-10 m2/s for the D. alata 9506-21 and 9506-27, respectively. The drying activation energy for D. alata 9506-21 and 9506-27 varied from 23.19 to 25.72, and 16.03 to 17.82 kJ/mol, respectively

Modelado de la cinética de secado de ñame (dioscorea rotundata) en capa delgada

El secado de ñame en capa delgada, de las variedades 9811-089 y 9811-091, fue evaluado en un secador de la-boratorio tipo bandeja a temperaturas de 45, 55 y 70 °C y velocidad de aire promedio de 1 m/s, en el Laboratorio de Ingeniería Aplicada de la Universidad de Córdoba; las muestras fueron adecuadas en geometría de rodajas de radio 3,19 cm y espesor de 0,5 cm y láminas de 0,5x3x5 cm. Se evaluó el efecto de la temperatura, variedad y geometría en el tiempo de secado, empleando un diseño completamente al azar en arreglo factorial con tres facto-res: temperatura (45, 55 y 70 °C), geometría (rodajas y láminas) y variedad (9811-089 y 9811-091), realizando tres repeticiones por tratamientoutilizando, dando como resultado una disminución en el tiempo de secado del 28,15% para la temperatura de 70 °C. Con los resultados obtenidos fueron construidas las curvas de secado, en las cuales se observó que este proceso tuvo lugar en el periodo decreciente, lo que evidencia que la difusión es el mecanismo que gobierna el secado de Dioscorea rotundata para las variedades estudiadas. Las curvas de secado fueron ajustadas a los modelos matemáticos de Page, difusión, Thompsom, Newton, Page modificado, Henderson y Pabis y el modelo logarítmico, determinando mediante el coeficiente de determinación (R2), error medio estimado (SE) y desvío medio relativo (%P), que el modelo logarítmico es el que mejor describe el proceso de secado (R2 ≥ 99.17 y SE ≤ 0.0299).Thin-layer yam (varieties 9811-089 and 9811-091) drying was evaluated in a laboratory-type dish dryer at 45°C, 55°C and 70°C and 1 m/s average air speed in the Universidad de Cordoba’s Applied Engineering laboratory. The samples were 3.19 cm long, 0.5 cm thick, in 0.5x3x5 cm slices. The effects of temperature, variety and geometry on drying-time were evaluated using a completely random factorial adjustment design: temperature (45°C, 55°C and 70°C), geometry (slices and fillets) and variety (9811-089 and 9811-091). Three repetitions were made per treat-ment, producing a 28.15% reduction in drying time at 70°C. Drying curves were constructed from the obtained re-sults; it was observed that drying took place during the decreasing period, proving that diffusion was the mechanism involved in Discorea rotundata drying for the studied varieties. Drying curves were adjusted to Page, diffusion, Thompson, Newton, modified Page, Henderson and Pabis mathematical models. The logarithmic model (determi-ned by determination coefficient (R2)) estimated mean error (SE) and relative mean deviation (%P), showing that the logarithmic model better described the drying process (R2 ≥ 99.17 and SE ≤ 0.0299)

Capitulo 2. Ciencias Naturales y Ciencias Básicas, Ingeniería y Tecnología

La diseminación de la Levitación Magnética, a pesar de lo antiguo de su tecnología, ha sido limitada. Debido a sus inconvenientes prácticos de implementación, su uso es bastante restringido, comparado con otras tecnologías (SCMaglev japonés, Transrapid alemán, o productos comerciales para ocio y entretenimiento). Con el boom de las tecnologías limpias y amigables con el medio ambiente y en concordancia con los objetivos del milenio, es pertinente plantearse el objetivo de optimizar el proceso de Levitación Magnética para generar un aprovechamiento de las ventajas de esta tecnología a nivel mecánico, eléctrico, y ambiental.  Actualmente la UNAD adelanta un proyecto de investigación cuyo objetivo es generar un modelo físico matemático de levitación magnética para aplicaciones en ingeniería. De este proyecto se ha derivado una primera revisión sistemática de los principios físicos y los modelos vigentes en Levitación Magnética

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Trayectorias de un viaje por la investigación educativa desde el sentipensar de los maestros y maestras : experiencias en desarrollo del programa de pensamiento crítico

428 páginasEste libro reúne 19 experiencias que continúan el acompañamiento en la fundamentación, desarrollo y estructuración de estrategias de tipo pedagógico y didáctico dentro de la ruta sentipensante en el Nivel II: Experiencias en desarrollo. Igualmente, en estas experiencias se hace una ampliación de referentes, técnicas e instrumentos para recoger información de los 19 textos presentados. De tal manera, estas experiencias son fruto de este acompañamiento que ha realizado el Instituto para la Investigación Educativa y el Desarrollo Pedagógico IDEP, que servirán de base y referente para seguir aportando en la configuración y consolidación de comunidades de saber y práctica pedagógica, así como en la conformación de colectivos y redes de maestros y maestras

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries