607 research outputs found

    Innovations in Traumatic Hemorrhage

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    Traumatic hemorrhagic injuries present a great problem to humanity and a challenge to medicine in the modern world. Current methods of treating these injuries in the field are ineffective and often extremely overkill or injurious. These methods are particularly inadequate when applied to the continuous high pressure bleeding that occurs from arterial wounds. Our project focuses on lowering the barriers to entry to innovation in the field of bleeding treatment by creating a low cost model of the human circulatory system. This model can function as a low-cost testing platform for novel bleeding treatments developed by companies and individuals that do not have the resources to regularly purchase extremely expensive cardiovascular simulators. To this end we designed a tripartite model which included a heart-simulating pump, vessel-simulating vasculature, and blood-mimicking fluid. In order to ensure our device functioned as a testing platform, we performed some preliminary solution candidate tests on it which had the ancillary benefit of identifying one effective but biologically unsafe solution that could be translated into a safe and efficacious future solution. Ultimately we found that our system functioned well as a testing platform for traumatic injury treatments and that standard silicone sealant administered by injection into the vessels had the greatest efficacy in stopping bleeding

    Arbitrary high order accurate space-time discontinuous Galerkin finite element schemes on staggered unstructured meshes for linear elasticity

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    In this paper we propose a new high order accurate space-time DG finite element scheme for the solution of the linear elastic wave equations in first order velocity-stress formulation in two and three-space dimensions on staggered unstructured triangular and tetrahedral meshes. The method reaches arbitrary high order of accuracy in both space and time via the use of space-time basis and test functions. Within the staggered mesh formulation, we define the discrete velocity field in the control volumes of a primary mesh, while the discrete stress tensor is defined on a face-based staggered dual mesh. The space-time DG formulation leads to an implicit scheme that requires the solution of a linear system for the unknown degrees of freedom at the new time level. The number of unknowns is reduced at the aid of the Schur complement, so that in the end only a linear system for the degrees of freedom of the velocity field needs to be solved. Thanks to the use of a spatially staggered mesh, the stencil of the final velocity system involves only the element and its direct neighbors. The resulting linear system can be efficiently solved via matrix-free iterative methods. The chosen discretization and the linear nature of the governing PDE system lead to an unconditionally stable scheme, which allows large time steps even for low quality meshes that contain sliver elements. The fully discrete staggered space-time DG method is proven to be energy stable for any order of accuracy, for any mesh and for any time step size. For the particular case of Crank-Nicolson time discretization and homogeneous material, the final velocity system can be proven to be symmetric and positive definite and in this case the scheme is also exactly energy preserving. The new scheme is applied to several test problems in two and three space dimensions, providing also a comparison with high order explicit ADER-DG scheme

    Effectiveness of dolutegravir-based regimens as either first-line or switch antiretroviral therapy: data from the Icona cohort

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    Introduction: Concerns about dolutegravir (DTG) tolerability in the real-life setting have recently arisen. We aimed to estimate the risk of treatment discontinuation and virological failure of DTG-based regimens from a large cohort of HIV-infected individuals. Methods: We performed a multicentre, observational study including all antiretroviral therapy (ART)-naïve and virologically suppressed treatment-experienced (TE) patients from the Icona (Italian Cohort Naïve Antiretrovirals) cohort who started, for the first time, a DTG-based regimen from January 2015 to December 2017. We estimated the cumulative risk of DTG discontinuation regardless of the reason and for toxicity, and of virological failure using Kaplan–Meier curves. We used Cox regression model to investigate predictors of DTG discontinuation. Results: About 1679 individuals (932 ART-naïve, 747 TE) were included. The one- and two-year probabilities (95% CI) of DTG discontinuation were 6.7% (4.9 to 8.4) and 11.5% (8.7 to 14.3) for ART-naïve and 6.6% (4.6 to 8.6) and 7.6% (5.4 to 9.8) for TE subjects. In both ART-naïve and TE patients, discontinuations of DTG were mainly driven by toxicity with an estimated risk (95% CI) of 4.0% (2.6 to 5.4) and 2.5% (1.3 to 3.6) by one year and 5.6% (3.8 to 7.5) and 4.0% (2.4 to 5.6) by two years respectively. Neuropsychiatric events were the main reason for stopping DTG in both ART-naïve (2.1%) and TE (1.7%) patients. In ART-naïve, a concomitant AIDS diagnosis predicted the risk of discontinuing DTG for any reason (adjusted relative hazard (aRH) = 3.38, p = 0.001), whereas starting DTG in combination with abacavir (ABC) was associated with a higher risk of discontinuing because of toxicity (aRH = 3.30, p = 0.009). TE patients starting a DTG-based dual therapy compared to a triple therapy had a lower risk of discontinuation for any reason (adjusted hazard ratio (aHR) = 2.50, p = 0.037 for ABC-based triple-therapies, aHR = 3.56, p = 0.012 for tenofovir-based) and for toxicity (aHR = 5.26, p = 0.030 for ABC-based, aHR = 6.60, p = 0.024 for tenofovir-based). The one- and two-year probabilities (95% CI) of virological failure were 1.2% (0.3 to 2.0) and 4.6% (2.7 to 6.5) in the ART naïve group and 2.2% (1.0 to 3.3) and 2.9% (1.5 to 4.3) in the TE group. Conclusions: In this large cohort, DTG showed excellent efficacy and optimal tolerability both as first-line and switching ART. The low risk of treatment-limiting toxicities in ART-naïve as well as in treated individuals reassures on the use of DTG in everyday clinical practice

    Gianni La Bella. Eduardo Francisco Pironio. Biografia di un cristiano latinoamericano. (Prefacio del Papa Francisco). Milán: Guerini e associati, 2023, 267 pp.

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    El cardenal argentino Eduardo Pironio (1920-1998) fue uno de los protagonistas de la Iglesia en América Latina durante el siglo XX. Su influencia en la renovación del catolicismo latinoamericano es indiscutible. Además de las actividades que desarrolló como obispo en Argentina y en América Latina fue uno de los más estrechos colabo-radores de Pablo VI y Juan Pablo II en el Vaticano; un referente ineludible para los Papas a la hora de tratar y decidir sobre los asuntos del continente. Pironio desempeñó un rol central en la configuración de los cambios de la Iglesia en el siglo XX. Fue uno de los artífices de la Conferencia del Episcopado Latinoamericano en Medellín (Colombia) en 1968, uno de los hitos más relevan-tes en la recepción del Concilio Vaticano II en el continente que marcó las siguientes décadas de la Iglesia en América Latina. Este libro es una excelente y novedosa biografía del carde-nal Eduardo Pironio basada en la consulta de documentación inédita de archivo. Ella nos abre, a través de una lectura ágil y atrapante, hacia aspectos desco-nocidos de la vida de Pironio

    Regionalismo sudamericano en el siglo XXI

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    Este trabajo toma la literatura existente sobre regionalismo Sudamericano en el siglo XXI, con el objetivo de revisar el estado del conocimiento. Se analiza lo que se escribió respecto al surgimiento de UNASUR, la relación entre la distribución del poder mundial y el regionalismo, y el liderazgo de Brasil, siendo estos los temas sistemáticamente tratados en los textos. Existen diferentes explicaciones respecto al origen de la Unión, pero la gran mayoría coincide en que la institución nació como consecuencia de los cambios que experimentó la región a partir de los años 2000. Uno de estos cambios fue la diversificación de las relaciones exteriores, lo que para muchos autores representa un desafío para la alianza regional y para algunos sólo podrá superarse con un liderazgo adecuado por parte de Brasil. Finalmente, se da cuenta de las limitaciones de la literatura, como por ejemplo la exclusión de actores relevantes en los análisis como son los actores no estatales, y se sugiere una mayor investigación sobre temas relacionados a las "nuevas amenazas"

    La sinodalidad en la Historia de la Iglesia Los cambios en las formas de autoridad entre el centralismo y la diversidad

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    This article aims to provide a general and in-depth look through the various forms of synodality throughout the history of the Church, from Christian antiquity to the present, with particular attention to the Latín American synodal tradition. Special attention is given to show how the different ages have characterized the various expressions of synodality according to their sensibilities and needs of the time and in parallel with the socio-political chariges.Este aporte tiene la finalidad de brindar una mirada general y profunda a modo de recorrido sobre las diversas formas de la sinodalidad a lo largo de la historia de la Iglesia, desde la antigüedad cristiana hasta el presente, con una particular atención a la tradición sinodal latinoamericana. Se presta particular atención a mostrar cómo las diversas épocas han caracterizado esta nota particular de la Iglesia de acuerdo a la sensibilidad y necesidades las diversas épocas y en paralelo con los cambios socio-políticos

    De la sacralidad de la naturaleza a la del hombre. La transformación de la religiosidad durante la Edad Media

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    Este artículo se concentra en el proceso de transformación de la religiosidad cristiana durante la Edad Media entre los siglos XI y XV. Muestra cómo la religiosidad, ancestralmente ligada al valor de la tierra y a los ciclos de la luz comienza a cambiar a medida que el hombre logra obtener otros medios de subsistencia centrados en la valoración de su propia capacidad humana. Los cambios demográficos, económicos, políticos y sociales desempeñan un rol central, y la religiosidad se mueve al mismo ritmo que estos factores. La autonomía respecto de los señores feudales, el auge de las ciudades libres, la producción artesanal y el comercio influyen notablemente en la comprensión y expresión religiosa que se centra en las capacidades humanas. El artículo intenta que el lector pueda comprender el movimiento y los principales componentes de este proceso a través de algunos ejemplos tomados de distintas áreas geográficas. La cultura medieval, y, por tanto, la religiosidad, continuarán su camino de transformación. Las necesidades y tensiones irresueltas del período que se expresan a través de la idea de reforma de la Iglesia nos sitúan en la antesala del surgimiento de las confesiones en el siglo XVI, donde éstas encuentran nuevos canales de expresión
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