108 research outputs found

    Principio de incertidumbre en los alimentos

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    Application of mathemathical models to infrared assisted drying process of lemon waste (Citrus limon (l.) Burm. F. Cv. genova)

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    Los desechos agroindustriales son uno de los principales problemas ambientales a nivel mundial. Debido a las altas exigencias de calidad, la comercialización de limones de exportación genera grandes cantidades de desechos. Los descartes de limón contienen fibra, pectina, potasio, calcio y vitamina C. Por lo tanto, es importante desarrollar alternativas de procesamiento de estos sub-productos para agregarles valor y aumentar su vida útil. El objetivo de la presente investigación fue la aplicación del secado asistido por infrarrojos, como tecnología emergente, para estudiar el efecto de la temperatura de proceso sobre las cinéticas de secado de descartes de limón a 30, 40 y 50°C. Se utilizaron seis modelos matemáticos de capa fi na encontrados en literatura para representar la cinética experimental. Basándose en análisis estadístico, el modelo Logarítmico presentó el mejor ajuste. Los valores de la difusividad efectiva del agua se estimaron en el rango de 9.45× 10-10 – 3.71× 10-9 m/s2 . El valor de la energía de activación fue 55.90 kJ/mol.Agroindustrial wastes are a major environmental problem worldwide. Due to high quality requirements, commercialization of export lemons generates huge amounts of wastes. Lemon wastes have fi ber, pectin, potassium, calcium and vitamin C. Therefore, it is important to develop alternative processing methods to add value and improve their shelf life. The aim of this work was to apply infrared drying, as an emergent technology, to study the effect of drying temperature on the drying kinetics of lemon waste at 30, 40 and 50°C. Six thin layer models found in literature were used to represent the experimental drying kinetics. Based on statistical tests, the Logarithmic model presented the best fi t. Values of moisture effective diffusivities were in the range of 9.45× 10-10 ? 3.71× 10-9 m/s2 . The value of activation energy was 55.90 kJ/mol.Fil: Puente Diaz, Luis. Universidad Católica de Chile. Facultad de Ciencias Químicas y Farmacéuticas; ChileFil: Echegaray Pacheco, Eric. Universidad Católica de Chile. Facultad de Ciencias Químicas y Farmacéuticas; ChileFil: Castro Montero, Eduardo. Universidad Católica de Chile. Facultad de Ciencias Químicas y Farmacéuticas; ChileFil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentin

    Estudio de infarto agudo de miocardio y su posible relación con las tormentas solares y geomagnéticas en Guantánamo

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    In order to compare previous results obtained in Cuba and other latitudes about the influence of solar and geomagnetic perturbations with the frequency of morbidity and mortality due to acute myocardial infarction, in this research we, propose a new analysis of the problem. The universe of patients will be used according to the daily registry of morbidity and mortality due to acute myocardial infarction at the Guantánamo General Teaching Hospital "Agostinho Neto" for 10 years (2001-2010). The data will be subjected to a statistical analysis with daily resolution, using windows, focused on days with high solar or geomagnetic activity, which will allow to analyze the frequency of acute myocardial infarction around those "active" days during the whole studied period, avoiding Other influences unrelated to the objective of the work. The sample will be characterized by sex and age groups, seasonality and other parameter.Con el objetivo de contrastar resultados anteriores, obtenidos en Cuba y en otras latitudes, acerca de la influencia de las perturbaciones solares y geomagnéticas con la frecuencia de la morbilidad y mortalidad por infarto agudo de miocardio, se propone realizar un nuevo análisis del problema. Se utilizará el universo de pacientes según el registro diario de morbilidad y mortalidad por infarto de agudo de miocardio del Hospital General Docente “Agostinho Neto” de Guantánamo, durante 10 años (2001-2010). La data será sometida a un análisis estadístico con resolución diaria, empleando ventanas, centradas en días con alta actividad solar o geomagnética, lo cual permitirá analizar la frecuencia de infarto agudo del miocardio alrededor de esos días “activos” durante todo el período estudiado, soslayando otras influencias ajenas al objetivo del trabajo. Se caracterizará la muestra según sexo y grupos etarios, estacionalidad y otros parámetros

    Variación genética de Balmea stormiae (Rubiaceae) en el centro-occidente de México

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    Background and Aims: Individuals of Balmea stormiae (Rubiaceae) are trees or hemiepiphytic shrubs that inhabit pine-oak forests on rock outcrops in disjunct populations of Central America and Mexico. The species is considered endangered and especially the populations of Michoacán have been reported as exposed to strong anthropogenic pressures. For this reason, in this study the genetic diversity of four populations of Michoacán was estimated, contrasting this information with that obtained from one population of Jalisco, both regions located in west-central Mexico.Methods: Samples were collected in five populations in the western region of the Trans-Mexican Volcanic Belt. The chloroplast rps16 intron, the external transcribed spacer of ribosomal DNA (ETS) and seven Inter-Simple Sequence Repeats of nuclear DNA (ISSR) were used to assess genetic diversity.Key results: Molecular markers revealed high genetic differentiation between the populations from Jalisco and Michoacán, attributed to the low connectivity amongst them, probably due to the low long distance dispersal capacity of seeds and pollen. Moderate genetic flow and demographic expansion were detected for populations in Michoacán. The degree of genetic diversity in Michoacán populations are consistent with the age of lava flows, whereby Arocutín and Zacapu are the most diverse populations located on the oldest lava flows.Conclusions: Results could be explained by the relatively recent origin, resulting from Holocene volcanic activity, of the environments in which the species inhabits, coupled with the recurring disturbance related to large pre-Hispanic settlements.Antecedentes y Objetivos: Los individuos de Balmea stormiae (Rubiaceae) son árboles o arbustos hemiepífitos que habitan malpaíses con bosques de pino-encino en poblaciones disyuntas en Centroamérica y México. La especie se considera en peligro de extinción y particularmente se ha documentado que las poblaciones de Michoacán han estado expuestas a fuertes presiones antropogénicas. Por tal motivo, en este estudio se estimó la diversidad genética en cuatro poblaciones de Michoacán, contrastando esta información con la obtenida en una población de Jalisco, ambas regiones ubicadas en el centro-occidente de México.Métodos: Las muestras vegetales fueron recolectadas en cinco poblaciones de la región occidente del Cinturón Volcánico Transmexicano. Para evaluar la diversidad genética, se utilizó el intrón rps16 del ADN de cloroplasto, el espaciador transcrito externo (ETS) del ADN ribosomal nuclear y marcadores dominantes ISSR de ADN nuclear (Inter Secuencias Simples Repetidas por sus siglas en inglés).Resultados clave: Los marcadores moleculares revelaron alta diferenciación genética entre las poblaciones de Jalisco y Michoacán, la cual se atribuye a la baja conectividad entre estas. Posiblemente se deba a la baja capacidad de dispersión a larga distancia de las semillas y el polen. Se detectó flujo genético moderado y expansión demográfica reciente en las poblaciones de Michoacán. Los niveles de variación genética en las poblaciones de Michoacán concuerdan con la edad de los flujos de lava, siendo Arocutín y Zacapu las poblaciones más diversas sobre los flujos de lava más antiguos.Conclusiones: Los resultados podrían explicarse por el origen relativamente reciente, producto de la actividad volcánica del Holoceno, de los ambientes en los que habita esta especie, sumado a la perturbación recurrente relacionada con grandes asentamientos prehispánicos de Michoacán

    Early Stepdown From Echinocandin to Fluconazole Treatment in Candidemia: A Post Hoc Analysis of Three Cohort Studies

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    [Background] There are no clear criteria for antifungal de-escalation after initial empirical treatments. We hypothesized that early de-escalation (ED) (within 5 days) to fluconazole is safe in fluconazole-susceptible candidemia with controlled source of infection.[Methods] This is a multicenter post hoc study that included consecutive patients from 3 prospective candidemia cohorts (2007–2016). The impact of ED and factors associated with mortality were assessed.[Results] Of 1023 candidemia episodes, 235 met inclusion criteria. Of these, 54 (23%) were classified as the ED group and 181 (77%) were classified as the non-ED group. ED was more common in catheter-related candidemia (51.9% vs 31.5%; P = .006) and episodes caused by Candida parapsilosis, yet it was less frequent in patients in the intensive care unit (24.1% vs 39.2%; P = .043), infections caused by Nakaseomyces glabrata (0% vs 9.9%; P = .016), and candidemia from an unknown source (24.1% vs 47%; P = .003). In the ED and non-ED groups, 30-day mortality was 11.1% and 29.8% (P = .006), respectively. Chronic obstructive pulmonary disease (odds ratio [OR], 3.97; 95% confidence interval [CI], 1.48–10.61), Pitt score > 2 (OR, 4.39; 95% CI, 1.94–9.20), unknown source of candidemia (OR, 2.59; 95% CI, 1.14–5.86), candidemia caused by Candida albicans (OR, 3.92; 95% CI, 1.48–10.61), and prior surgery (OR, 0.29; 95% CI, 0.08–0.97) were independent predictors of mortality. Similar results were found when a propensity score for receiving ED was incorporated into the model. ED had no significant impact on mortality (OR, 0.50; 95% CI, 0.16–1.53).[Conclusions] Early de-escalation is a safe strategy in patients with candidemia caused by fluconazole-susceptible strains with controlled source of bloodstream infection and hemodynamic stability. These results are important to apply antifungal stewardship strategies.This research forms part of an activity that has received funding from EIT Health. EIT Health is supported by the European Institute of Innovation and Technology (EIT), a body of the European Union that receives support from the European Union´s Horizon 2020 Research and Innovation Program. This study has been cofunded by the European Regional Development Fund. E. M.-G. (PI18/01061), P. P.-A. (“Rio Hortega” contract CM18/00132), M. F.-R. (“Miguel Servet” contract CP18/00073), and C. G.-V. (FIS PI18/01061) have received research grants from the Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III.Peer reviewe

    Study protocol and rationale of the “Cogniaction project” a cross-sectional and randomized controlled trial about physical activity, brain health, cognition, and educational achievement in schoolchildren

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    Background: Education and health are crucial topics for public policies as both largely determine the future wellbeing of the society. Currently, several studies recognize that physical activity (PA) benefits brain health in children. However, most of these studies have not been carried out in developing countries or lack the transference into the education field. The Cogni-Action Project is divided into two stages, a cross-sectional study and a crossover-randomized trial. The aim of the first part is to establish the associations of PA, sedentarism, and physical fitness with brain structure and function, cognitive performance and academic achievement in Chilean schoolchildren (10–13 years-old). The aim of the second part is to determinate the acute effects of three PA protocols on neuroelectric indices during a working memory and a reading task. Methods: PA and sedentarism will be self-reported and objectively-assessed with accelerometers in a representative subsample, whilst physical fitness will be evaluated through the ALPHA fitness test battery. Brain structure and function will be assessed by magnetic resonance imaging (MRI) in a randomized subsample. Cognitive performance will be assessed through the NeuroCognitive Performance Test, and academic achievement by school grades. In the second part 32 adolescents (12–13 year-old) will be cross-over randomized to these condition (i) “Moderate-Intensity Continuous Training” (MICT), (ii) “Cooperative High-Intensity Interval Training” (C-HIIT), and (iii) Sedentary condition. Neuroelectric indices will be measures by electroencephalogram (EEG) and eye-tracking, working memory by n-back task and reading comprehension by a reading task

    Flagellin from Marinobacter algicola and Vibrio vulnificus activates the innate immune response of gilthead seabream

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    Adjuvants emerge as the better tool to enhance the efficacy of vaccination. Traditional adjuvants used in aquaculture cause adverse alterations in fish. Thus, it is necessary the development of new adjuvants able to stimulate the immune system and generate high protection against infectious pathogens with minimal undesirable effects. To this end, flagellin emerges as an attractive candidate due to its potency to stimulate the immune response of fish. In the current study, we have evaluated the ability of recombinant flagellin from Marinobacter algicola (MA) and Vibrio vulnificus (Vvul), a non-pathogenic and a pathogenic bacteria, respectively, to stimulate the innate immune system of gilthead seabream (Sparus aurata L.) in comparison with the classical flagellin from Salmonella enterica serovar Thyphimurium (Salmonella Thyphimurium, STF). Intraperitoneal injection of MA and Vvul resulted in a strong inflammatory response characterized by increased reactive oxygen species production and the infiltration of acidophilic granulocytes at the injection site. Interestingly, however, only flagellin from MA consistently induced the expression of the gene encoding pro-inflammatory interleukin-1. These effects were further confirmed in vitro, where a dose-dependent activation of macrophages and acidophilic granulocytes by MA and Vvul flagellins was observed. In contrast, STF flagellin was found to be less potent in either in vivo or in vitro experiments. Our results suggest the potential use of MA and Vvul flagellins as immunostimulants and adjuvants for fish vaccination.Postprin

    Engineering NK-CAR.19 cells with the IL-15/IL-15Rα complex improved proliferation and anti-tumor effect in vivo

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    IntroductionNatural killer 92 (NK-92) cells are an attractive therapeutic approach as alternative chimeric antigen receptor (CAR) carriers, different from T cells, once they can be used in the allogeneic setting. The modest in vivo outcomes observed with NK-92 cells continue to present hurdles in successfully translating NK-92 cell therapies into clinical applications. Adoptive transfer of CAR-NK-92 cells holds out the promise of therapeutic benefit at a lower rate of adverse events due to the absence of GvHD and cytokine release syndrome. However, it has not achieved breakthrough clinical results yet, and further improvement of CAR-NK-92 cells is necessary.MethodsIn this study, we conducted a comparative analysis between CD19-targeted CAR (CAR.19) co-expressing IL-15 (CAR.19-IL15) with IL-15/IL-15Rα (CAR.19-IL15/IL15Rα) to promote NK cell proliferation, activation, and cytotoxic activity against B-cell leukemia. CAR constructs were cloned into lentiviral vector and transduced into NK-92 cell line. Potency of CAR-NK cells were assessed against CD19-expressing cell lines NALM-6 or Raji in vitro and in vivo in a murine model. Tumor burden was measured by bioluminescence.ResultsWe demonstrated that a fourth- generation CD19-targeted CAR (CAR.19) co-expressing IL-15 linked to its receptor IL-15/IL-15Rα (CAR.19-IL-15/IL-15Rα) significantly enhanced NK-92 cell proliferation, proinflammatory cytokine secretion, and cytotoxic activity against B-cell cancer cell lines in vitro and in a xenograft mouse model.ConclusionTogether with the results of the systematic analysis of the transcriptome of activated NK-92 CAR variants, this supports the notion that IL-15/IL-15Rα comprising fourth-generation CARs may overcome the limitations of NK-92 cell-based targeted tumor therapies in vivo by providing the necessary growth and activation signals

    El «momento mutualista» en la formulación de un sistema de protección social en Argentina: socorro mutuo y prevención subsidiada a comienzos del siglo XX

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    In this article I study the foreigners’ mutual aid practices and their role in the diffusion of solidarist thinking that would provide a set of conceptual tools and techniques that would be essential in the demands for protection coming from workers and in formulating the first projects for putting in place a national insurance system. This research allow me to point out the transnational dimension of the construction of the field of social protection. The first part of the article is an empirical demonstration of this reality using qualitative and quantitative sources from public and private archives. In the second one I pay attention to the concrete mechanisms in the circulation of knowledge. In particular, the article analyses the different mutualist congresses organized in Buenos Aires during the first two decades of the twentieth century and the impact of the visit of Léopold Mabilleau, a French intellectual, expert in mutual insurance systems and «apostle» of solidarism.Este trabajo está destinado a estudiar las prácticas de socorro mutuo de los extranjeros y su papel en la difusión de un pensamiento solidarista que proporcionará un conjunto de herramientas conceptuales y técnicas esenciales para las reivindicaciones de protección por parte de los trabajadores así como para la formulación de los primeros proyectos de creación de un sistema nacional de seguro social. Ello me permite destacar la dimensión transnacional de la construcción del campo de la protección social. La primera parte del artículo está destinada a dar cuenta de esta realidad empírica a partir de un trabajo de fuentes cuantitativas y cualitativas y de archivos públicos y privados. La segunda pone en evidencia los mecanismos concretos de la circulación de saberes. El artículo analiza en particular los diferentes congresos mutualistas que se organizan en Buenos Aires durante las dos primeras décadas del siglo XX y el impacto de la visita de Léopold Mabilleau, intelectual francés, experto en mutualidades y «apóstol» del solidarismo

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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