1,395 research outputs found

    A composite hydrogel for brain tissue phantoms

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    Synthetic phantoms are valuable tools for training, research and development in traditional and computer aided surgery, but complex organs, such as the brain, are difficult to replicate. Here, we present the development of a new composite hydrogel capable of mimicking the mechanical response of brain tissue under loading. Our results demonstrate how the combination of two different hydrogels, whose synergistic interaction results in a highly tunable blend, produces a hybrid material that closely matches the strongly dynamic and non-linear response of brain tissue. The new synthetic material is inexpensive, simple to prepare, and its constitutive components are both widely available and biocompatible. Our investigation of the properties of this engineered tissue, using both small scale testing and life-sized brain phantoms, shows that it is suitable for reproducing the brain shift phenomenon and brain tissue response to indentation and palpation

    Impacto de la Planeación estratégica en el servicio al cliente en un consultorio dental

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    One of the purposes of implementing strategic planning in a dental office is to impact the quality of service in such a way that it raises business expectations within a market where we find fierce competition, so our article addresses how to compete with tools provided by the strategies implemented since most small businesses that start new operations do not have a strategic plan for take possession as a business with high quality in its service and according to the demands they have today such as the use of social networks to advertise the business, the agenda of appointments for consultations, the need to hire the services of support staff and as a consequence the increase of all administrative and service tasks,  making it necessary to establish administrative processes within the business for the proper functioning and improve the dental service offered to the public ...Uno de los propósitos de la implementación de la planeación estratégica en un consultorio dental es impactar la calidad del servicio de tal manera que eleve las expectativas del negocio dentro de un mercado donde encontramos una competencia feroz, por lo que nuestro artículo aborda la manera de competir con herramientas proporcionadas por las estrategias implementadas ya que la mayoría de las pequeñas empresas que inician nuevas operaciones no cuentan con un plan estratégico para posesionarse como un negocio con alta calidad en su servicio y acorde a las exigencias que tienen en la actualidad como el uso de las redes sociales para publicitar el negocio, la agenda de citas para consultas, la necesidad de contratar los servicios de personal de apoyo y como consecuencia el incremento de todas las tareas administrativas y de servicio, haciendo necesario establecer procesos administrativos dentro del negocio para el correcto funcionamiento y mejorar el servicio dental que se ofrece al público

    Insights into infusion-based targeted drug delivery in brain: perspectives, challenges and opportunities

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    Targeted drug delivery in the brain is instrumental in the treatment of lethal brain diseases, such as glioblastoma multiforme, the most aggressive primary central nervous system tumour in adults. Infusion-based drug delivery techniques, which directly administer to the tissue for local treatment, as in convection-enhanced delivery (CED), provide an important opportunity; however, poor understanding of the pressure-driven drug transport mechanisms in the brain has hindered its ultimate success in clinical applications. In this review, we focus on the biomechanical and biochemical aspects of infusion-based targeted drug delivery in the brain and look into the underlying molecular level mechanisms. We discuss recent advances and challenges in the complementary field of medical robotics and its use in targeted drug delivery in the brain. A critical overview of current research in these areas and their clinical implications is provided. This review delivers new ideas and perspectives for further studies of targeted drug delivery in the brain

    Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

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    At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.Peer reviewe

    Variability in the analysis of a single neuroimaging dataset by many teams

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    Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed
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