342 research outputs found

    A Computational Model for Biomass Growth Simulation in Tissue Engineering

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    This article deals with computational modeling of tissue growth under interstitial perfusion inside a polymeric scaffold-based bioreactor. The mathematical model is the result of the application of the volume averaging technique to the fluid, nutrient and cellular subsystems, and is capable to account for the temporal evolution of local matrix porosity, as the sum of a time-invariant component (the porosity of the uncellularized polymer scaffold) and a time-dependent component (due to the growing biomass). The solution algorithm is based on a block Gauss-Seidel iteration procedure that allows to reduce each time level of the simulated culture period into the successive solution of linearized subproblems, whose numerical approximation is carried out using stable and convergent finite elements. Numerical simulations are carried out to investigate the role of the design porosity of the scaffold on nutrient delivery and biomass production

    Le reti di impresa nella politica industriale. I contratti di rete e i contratti di sviluppo.

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    Le reti di impresa si sono affermate come un modello organizzativo e competitivo compiutamente alternativo sia al mercato sia alla gerarchia, superando una visione teorica che tendeva a confinarle come modello imperfetto o immaturo del capitalismo. I contributi raccolti nel volume, frutto di un lavoro di ricerca multidisciplinare, analizzano i presupposti teorici delle reti e si concentrano su due principali strumenti di politica industriale – i contratti di rete e i contratti di sviluppo – avvalendosi dei risultati emersi dai percorsi di attuazione di casi selezionati in quattro regioni italiane

    Antioxidant and Anti-Inflammatory Effect of Cinnamon (Cinnamomum verum J. Presl) Bark Extract after In Vitro Digestion Simulation

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    Cinnamon bark is widely used for its organoleptic features in the food context and growing evidence supports its beneficial effect on human health. The market offers an increasingly wide range of food products and supplements enriched with cinnamon extracts which are eliciting beneficial and health-promoting properties. Specifically, the extract of Cinnamomum spp. is rich in antioxidant, anti-inflammatory and anticancer biomolecules. These include widely reported cinnamic acid and some phenolic compounds, such asproanthocyanidins A and B, and kaempferol. These molecules are sensitive to physical-chemical properties (such as pH and temperature) and biological agents that act during gastric digestion, which could impair molecules' bioactivity. Therefore, in this study, the cinnamon's antioxidant and anti-inflammatory bioactivity after simulated digestion was evaluated by analyzing the chemical profile of the pure extract and digested one, as well as the cellular effect in vitro models, such as Caco2 and intestinal barrier. The results showed that the digestive process reduces the total content of polyphenols, especially tannins, while preserving other bioactive compounds such as cinnamic acid. At the functional level, the digested extract maintains an antioxidant and anti-inflammatory effect at the cellular level

    Flux-Upwind Stabilization of the Discontinuous Petrov--Galerkin Formulation with Lagrangian Multipliers for Advection-Diffusion Problems

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    In this work we consider the dual-primal Discontinuous Petrov-Galerkin (DPG) method for the advection-diffusion model problem. Since in the DPG method both mixed internal variables are discontinuous, a static condensation procedure can be carried out, leading to a single-field nonconforming discretization scheme. For this latter formulation, we propose a flux-upwind stabilization technique to deal with the advection-dominated case. The resulting scheme is conservative and satisfies a discrete maximum principle under standard geometrical assumptions on the computational grid. A convergence analysis is developed, proving first-order accuracy of the method in a discrete H^1-norm, and the numerical performance of the scheme is validated on benchmark problems with sharp internal and boundary layers

    Aplicación Alertamos

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    Fil: Sacco, Maximiliano A. Servicio Meteorológico Nacional. Gerencia de Investigación, Desarrollo y Capacitación. Departamento de Investigación y Desarrollo; Argentina.Fil: García Skabar, Yanina. Servicio Meteorológico Nacional. Gerencia de Investigación, Desarrollo y Capacitación. Departamento de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Franco Argentino sobre Estudios del Clima y sus Impactos; Argentina.Fil: Salio, Paola Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos; Argentina.Fil: Vidal, Luciano. Servicio Meteorológico Nacional. Gerencia de Investigación, Desarrollo y Capacitación. Departamento de Investigación y Desarrollo; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y Los Océanos; Argentina.Alertamos es una aplicación móvil desarrollada con el fin de recolectar información de fenómenos meteorológicos de superficie que observan los ciudadanos y visualizar reportes georeferenciados enviados por todos los usuarios. La aplicación se encuentra disponible para dispositivos Android y Iphone y también en su versión web. En el presente informe se describen las características, la arquitectura y las tecnologías que se utilizan para el desarrollo y funcionamiento de la aplicación. Asimismo se hace un análisis de las estadísticas de uso de la aplicación y de la base de datos de reportes.Alertamos is a mobile application developed with the purpose of collecting information of surface meteorological phenomena observed by citizens and visualizing georeferenced reports sent by all users. The application is available in its web version as well as for Android and Iphone devices. This report describes the characteristics, architecture and technologies used for the development and operation of the application. In addition, analysis of the statistics of the application use and reports in the database is performed

    The protective effect of bergamot oil extract on lecitine-like oxyLDL receptor-1 expression in balloon injury-related neointima formation.

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    Lectin-like oxyLDL receptor-1 (LOX-1) has recently been suggested to be involved in smooth muscle cell (SMC) proliferation and neointima formation in injured blood vessels. This study evaluates the effect of the nonvolatile fraction (NVF), the antioxidant component of bergamot essential oil (BEO), on LOX-1 expression and free radical generation in a model of rat angioplasty. Common carotid arteries injured by balloon angioplasty were removed after 14 days for histopathological, biochemical, and immunohistochemical studies. Balloon injury led to a significant restenosis with SMC proliferation and neointima formation, accompanied by increased expression of LOX-1 receptor, malondialdehyde and superoxide formation, and nitrotyrosine staining. Pretreatment of rats with BEO-NVF reduced the neointima proliferation together with free radical formation and LOX-1 expression in a dose-dependent manner. These results suggest that natural antioxidants may be relevant in the treatment of vascular disorders in which proliferation of SMCs and oxyLDL-related endothelial cell dysfunction are involved

    Dual-responsive magnetic nanodroplets for controlled oxygen release via ultrasound and magnetic stimulation

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    Magnetic oxygen-loaded nanodroplets (MOLNDs) are a promising class of nanomaterials dually sensitive to ultrasound and magnetic fields, which can be employed as nanovectors for drug delivery applications, particularly in the field of hypoxic tissue treatment. Previous investigations were primarily focused on the application of these hybrid systems for hyperthermia treatment, exploiting magnetic nanoparticles for heat generation and nanodroplets as carriers and ultrasound contrast agents for treatment progress monitoring. This work places its emphasis on the prospect of obtaining an oxygen delivery system that can be activated by both ultrasound and magnetic fields. To achieve this goal, Fe3O4 nanoparticles were employed to decorate and induce the magnetic vaporization of OLNDs, allowing oxygen release. We present an optimized method for preparing MOLNDs by decorating nanodroplets made of diverse fluorocarbon cores and polymeric coatings. Furthermore, we performed a series of characterizations for better understanding how magnetic decoration can influence the physicochemical properties of OLNDs. Our comprehensive analysis demonstrates the efficacy of magnetic stimulation in promoting oxygen release compared to conventional ultrasound-based methods. We emphasize the critical role of selecting the appropriate fluorocarbon core and polymeric coating to optimize the decoration process and enhance the oxygen release performance of MOLNDs

    Chemotherapy effects on brain glucose metabolism at rest

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    Background: A growing number of studies reports that chemotherapy may impair brain functions inducing cognitive changes which can persist in a subset of cancer survivors. Aims: To investigate the neural basis of the chemotherapy-induced neurobehavioral changes by means of metabolic imaging and voxel-based statistical parametric mapping analyses. Methods: We studied the resting brain [18]FDG-PET/CT images of 43 adult cancer patients with solid (n=12, 28%) or hematologic malignancies (n=31, 72%); 12 patients were studied prior to chemotherapy (No chemotherapy) while treated patients were divided into two matched subgroups: Early High (6 chemotherapy cycles, n=10), and Late Low (>9 months after chemotherapy, <6 chemotherapy cycles, n=21). Findings: Compared to No chemotherapy, the Early High subgroup showed a significant bilateral (p<0.05) lower regional cerebral metabolic rate of glucose metabolism in both the prefrontal cortices and white matter, cerebellum, posterior medial cortices and limbic regions. A similar pattern emerged in the Early High versus Low Late comparison, while no significant result was obtained in the Low Late versus No chemotherapy comparison. The number of cycles and the post-chemotherapy time were negatively and positively correlated, respectively, with a set of these same brain regions. Interpretation: The present study shows that chemotherapy induces significant transient changes in the glucose metabolism of multiple cerebral cortical and white matter regions with a prevailing involvement of the prefrontal cortex. The severity of these changes are significantly related with the number of chemotherapy cycles and a subset of brain regions seems to present longer lasting, but more subtle, metabolic changes
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