139 research outputs found

    A Pseudopterane Diterpene Isolated From the Octocoral Pseudopterogorgia acerosa Inhibits the Inflammatory Response Mediated by TLR-Ligands and TNF-Alpha in Macrophages

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    Several diterpenoids isolated from terrestrial and marine environments have been identified as important anti-inflammatory agents. Although considerable progress has been made in the area of anti-inflammatory treatment, the search for more effective and safer compounds is a very active field of research. In this study we investigated the anti-inflammatory effects of a known pseudopterane diterpene (referred here as compound 1) isolated from the octocoral Pseudopterogorgia acerosa on the tumor necrosis factor- alpha (TNF-α) and TLRs- induced response in macrophages. Compound 1 inhibited the expression and secretion of the inflammatory mediators TNF-α, interleukin (IL)-6, IL-1β, nitric oxide (NO), interferon gamma-induced protein 10 (IP-10), ciclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and monocyte chemoattractant protein-1 (MCP-1) induced by LPS in primary murine macrophages. This effect was associated with the inhibition of IκBα degradation and subsequent activation of NFκB. Compound 1 also inhibited the expression of the co-stimulatory molecules CD80 and CD86, which is a hallmark of macrophage activation and consequent initiation of an adaptive immune response. The anti-inflammatory effect was not exclusive to LPS because compound 1 also inhibited the response of macrophages to TNF-α and TLR2 and TLR3 ligands. Taken together, these results indicate that compound 1 is an anti-inflammatory molecule, which modulates a variety of processes occurring in macrophage activation.Several diterpenoids isolated from terrestrial and marine environments have been identified as important anti-inflammatory agents. Although considerable progress has been made in the area of anti-inflammatory treatment, the search for more effective and safer compounds is a very active field of research. In this study we investigated the anti-inflammatory effects of a known pseudopterane diterpene (referred here as compound 1) isolated from the octocoral Pseudopterogorgia acerosa on the tumor necrosis factor- alpha (TNF-α) and TLRs- induced response in macrophages. Compound 1 inhibited the expression and secretion of the inflammatory mediators TNF-α, interleukin (IL)-6, IL-1β, nitric oxide (NO), interferon gamma-induced protein 10 (IP-10), ciclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and monocyte chemoattractant protein-1 (MCP-1) induced by LPS in primary murine macrophages. This effect was associated with the inhibition of IκBα degradation and subsequent activation of NFκB. Compound 1 also inhibited the expression of the co-stimulatory molecules CD80 and CD86, which is a hallmark of macrophage activation and consequent initiation of an adaptive immune response. The anti-inflammatory effect was not exclusive to LPS because compound 1 also inhibited the response of macrophages to TNF-α and TLR2 and TLR3 ligands. Taken together, these results indicate that compound 1 is an anti-inflammatory molecule, which modulates a variety of processes occurring in macrophage activation

    Estudio del remojado de soja cruda: Desarrollo de un modelo matemático que considera expansión volumétrica y coeficiente de difusión variable

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    La soja tiene un alto contenido proteico (40% m/m) y un buen balance de aminoácidos, siendo un recurso ideal para complementar la alimentación. A efectos de desarrollar un producto snack a partir de soja remojada por secado-tostado en lecho fluidizado, el objetivo de este trabajo fue estudiar en detalle la cinética de transferencia de materia durante la etapa de remojado. El procedimiento experimental consistió en depositar los granos de soja cruda en un baño termostatizado con agitación, relación 20:1 (agua: granos), a temperaturas de 20, 40, 60 y 80ºC. Para determinar el incremento en el contenido de humedad y la variación de volumen en el grano durante el proceso, se extrajeron muestras a diferentes tiempos (t), entre 5 y 300 min. En base a conocimientos previos obtenidos por los autores de este trabajo, en el modelado del secado-tostado de soja en lecho fluidizado. Los datos experimentales obtenidos en el presente estudio condujeron al desarrollo de un modelo de expansión volumétrica que relacionó el radio del grano (R) con la humedad media (Wm). Para la resolución del balance de materia se consideró geometría esférica con difusión radial y se aplicó el método numérico de diferencias finitas en esquema implícito. El coeficiente de difusión (D) se propuso como una función de la temperatura y el contenido de humedad. La dependencia con la temperatura se realizó mediante una ecuación tipo Arrhenius, mientras que la funcionalidad con la humedad a través del modelo de expansión volumétrica a nivel local. Las curvas de Wm vs t predichas se ajustaron satisfactoriamente a los datos experimentales obteniéndose r2≥0,98 y un error cuadrático medio (ECM)≤0,07 (expresado en unidades de la variable dependiente). Con el propósito de mantener la integridad del grano y evitar una posible desnaturalización de proteínas (T≥60ºC) se consideró que las condiciones óptimas de proceso fueron: 40ºC durante 150 min (2,5 h). El modelo desarrollado puede presentar gran utilidad en el diseño de equipos, predicción de tiempos de proceso y cálculos del consumo energético.Fil: Estepa Restrepo, S. L.. Universidad de Antioquia; ColombiaFil: Torrez Irigoyen, Ricardo Martin. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Giner, Sergio Adrian. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaXXI Congreso Latinoamericano y del Caribe de Ciencia y Tecnología de Alimentos y XVII Congreso Argentino de Ciencia y Tecnología de AlimentosBuenos AiresArgentinaAsociación Argentina de Tecnólogos AlimentariosAsociación Latinoamericana y del Caribe de Ciencia y Tecnología de Alimento

    SOBRE LOS EVENTOS QUE SE DESATAN CUANDO LA LUZ INCIDE SOBRE UNA NANOESTRUCTURA

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    La interacción de la radiación con la materia es un hecho cotidiano en la naturaleza, se pueden recordar  fenómenos como la fotosíntesis, interacción de la luz solar con las plantas para generar alimento y la generación de la vitamina D en nuestra piel. Con la formación de sistemas masivos, galaxias, estrellas, planetas, en los albores del universo, se establece la radiación electromagnética, la cual se caracteriza por contener ondas con longitudes desde los kilómetros, ondas de radio, hasta longitudes menores que 10-12 m, rayos gama, pasando por la radiación visible detectada por nuestra retina. En este artículo divulgativo, dirigido al público en general, basado en la investigación de Duque et al [1], se va a tratar acerca de los conceptos involucrados en la interacción de la luz con nanoestructuras semiconductoras.The interaction of radiation with matter is an everyday event in nature, we can recall phenomena such as photosynthesis, sunlight interaction with plants to produce food and the generation of vitamin D in our skin. With the formation of massive systems, galaxies, stars, planets, in the early universe, electromagnetic radiation was established, which is characterized by containing wavelengths from the kilometer radio waves to shorter lengths 10-12 m, gamma rays, through visible radiation detected by the retina. In this informative article, for the general public, based on the work by Duque et al [1], the objective is to describe the concepts involved in the interaction of light with semiconductor nanostructures

    Simulating the detection of the global 21 cm signal with MIST for different models of the soil and beam directivity

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    The Mapper of the IGM Spin Temperature (MIST) is a new ground-based, single-antenna, radio experiment attempting to detect the global 21 cm signal from the Dark Ages and Cosmic Dawn. A significant challenge in this measurement is the frequency-dependence, or chromaticity, of the antenna beam directivity. MIST observes with the antenna above the soil and without a metal ground plane, and the beam directivity is sensitive to the electrical characteristics of the soil. In this paper, we use simulated observations with MIST to study how the detection of the global 21 cm signal from Cosmic Dawn is affected by the soil and the MIST beam directivity. We simulate observations using electromagnetic models of the directivity computed for single- and two-layer models of the soil. We test the recovery of the Cosmic Dawn signal with and without beam chromaticity correction applied to the simulated data. We find that our single-layer soil models enable a straightforward recovery of the signal even without chromaticity correction. Two-layer models increase the beam chromaticity and make the recovery more challenging. However, for the model in which the bottom soil layer has a lower electrical conductivity than the top layer, the signal can be recovered even without chromaticity correction. For the other two-layer models, chromaticity correction is necessary for the recovery of the signal and the accuracy requirements for the soil parameters vary between models. These results will be used as a guideline to select observation sites that are favorable for the detection of the Cosmic Dawn signal.Comment: Accepted for publication in the Astrophysical Journa

    Would you give a quantum ring to your fiancee?

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    ABSTRACT: A quantum ring is a physical object similar to a real life ring that we find in our daily life, the only difference is in its very small nanometer dimensions (0.000000001 m). Furthermore, the ring is made of a semiconductor material called gallium arsenide (GaAs), as opposed to ordinary rings generally made of gold or silver. Another difference with the real ring is that it only has two dimensions, this means that it looks like a hole coin with negligible thickness. To the naked eye, this system could appear too ideal and not useful; but, these structures can be produced experimentally with very small thicknesses close to the system studied here and they have large enough important applications for the actual world.RESUMEN: Un anillo cuántico es un sistema físico similar a un anillo cualquiera que encontramos en nuestra vida cotidiana, la única diferencia es que sus dimensiones son muy pequeñas, en el rango de nanómetros (0.000000001 m). Además, en este caso el anillo es de un material semiconductor llamado arseniuro de galio (GaAs), a diferencia de los anillos que usamos en la vida cotidiana que son de oro y plata. Otra diferencia es que el anillo que se estudió en este trabajo solo tiene dos dimensiones, esto quiere decir que se parece a una moneda hueca con un espesor despreciable. A simple vista, este sistema puede parecer muy ideal y poco útil; pero, estas estructuras se pueden producir experimentalmente, con un espesor muy delgado de unas cuantas capas atómicas, muy cercanas al sistema aquí considerado y tienen muchas aplicaciones importantes en el mundo actual

    A task force for diagnosis and treatment of people with Alzheimer’s disease in Latin America

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    Alzheimer’s disease (AD) represents a substantial burden to patients, their caregivers, health systems, and society in Latin America and the Caribbean (LAC). This impact is exacerbated by limited access to diagnosis, specialized care, and therapies for AD within and among nations. The region has varied geographic, ethnic, cultural, and economic conditions, which create unique challenges to AD diagnosis and management. To address these issues, the Americas Health Foundation convened a panel of eight neurologists, geriatricians, and psychiatrists from Argentina, Brazil, Colombia, Ecuador, Guatemala, Mexico, and Peru who are experts in AD for a three-day virtual meeting to discuss best practices for AD diagnosis and treatment in LAC and create a manuscript offering recommendations to address identified barriers. In LAC, several barriers hamper diagnosing and treating people with dementia. These barriers include access to healthcare, fragmented healthcare systems, limited research funding, unstandardized diagnosis and treatment, genetic heterogeneity, and varying social determinants of health. Additional training for physicians and other healthcare workers at the primary care level, region-specific or adequately adapted cognitive tests, increased public healthcare insurance coverage of testing and treatment, and dedicated search strategies to detect populations with gene variants associated with AD are among the recommendations to improve the landscape of AD

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Antifungal activity of amphotericin B conjugated to nanosized magnetite in the treatment of paracoccidioidomycosis

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    This study reports on in vitro and in vivo tests that sought to assess the antifungal activity of a newly developed magnetic carrier system comprising amphotericin B loaded onto the surface of pre-coated (with a double-layer of lauric acid) magnetite nanoparticles. The in vitro tests compared two drugs; i.e., this newly developed form and free amphotericin B. We found that this nanocomplex exhibited antifungal activity without cytotoxicity to human urinary cells and with low cytotoxicity to peritoneal macrophages. We also evaluated the efficacy of the nanocomplex in experimental paracoccidioidomycosis. BALB/c mice were intratracheally infected with Paracoccidioides brasiliensis and treated with the compound for 30 or 60 days beginning the day after infection. The newly developed amphotericin B coupled with magnetic nanoparticles was effective against experimental paracoccidioidomycosis, and it did not induce clinical, biochemical or histopathological alterations. The nanocomplex also did not induce genotoxic effects in bone marrow cells. Therefore, it is reasonable to believe that amphotericin B coupled to magnetic nanoparticles and stabilized with bilayer lauric acid is a promising nanotool for the treatment of the experimental paracoccidioidomycosis because it exhibited antifungal activity that was similar to that of free amphotericin B, did not induce adverse effects in therapeutic doses and allowed for a reduction in the number of applications
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