1,720,963 research outputs found
An objective approach for digital removal of bifurcation aneurysms: incremental improvements?
No full textAutomated and objective removal of bifurcation aneurysms: incremental improvements, and validation against healthy controls
Get PDFCharacterization of Vessel Wall Vibrations of an Arteriovenous Fistula Over the Maturation Period
No full textArteriovenous fistula (AVF) is the preferred vascular access for hemodialysis, but is still associated with a high failure rate. This study aims at characterizing AVF changes in vessel wall vibrations during the maturation period. Three-dimensional AVF models were generated from MR images
acquired 3 days and 6 weeks after surgery in a 72-year-old male patient. Blood velocities obtained from Ultrasound were imposed as boundary conditions for high-fidelity fluid-structure interaction simulations. Results showed predominant wall vibrations between anastomosis and perianastomotic vein, the typical areas where the stenosis develops, highlighting their potential role in the mechanobiological process responsible for AVF failure
A unified method for estimating pressure losses at vascular junctions
Get PDFIn reduced-order (0D/1D) blood or respiratory flow models, pressure losses at junctions are usually neglected. However, these may become important where velocities are high and significant flow redirection occurs. Current methods for estimating losses rely on relatively complex empirical equations that are only valid for specific junction geometries and flow regimes. In pulsatile multi-directional flows, switching between empirical equations upon reversing flow may introduce unrealistic discontinuities in simulated haemodynamic waveforms. Drawing from work by Bassett et al. (SAE Trans 112:565-583, 2003), we therefore developed a unified method (Unified0D) for estimating loss coefficients that can be applied to any junction (i.e. any number of branches at any angle) and any flow regime. Discontinuities in simulated waveforms were avoided by extending Bassett et al.'s control volume-based method to incorporate a 'pseudodatum' supplier branch, an imaginary effective vessel containing all inflow to the junction. Energy exchange between diverging flow streams was also accounted for empirically. The formulation was validated using high resolution computational fluid dynamics in a wide range flow conditions and junction configurations. In a pulsatile 1D simulation exhibiting transitions between four different flow regimes, the new formulation produced smooth transitions in calculated pressure losses
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Building credibility of computational models in cardiovascular medicine through verification and validation
No full text[EN] Cardiovascular diseases affect 15 million
people in Europe and digital solutions
are now seen as very useful tools in the
search for new drugs and medical devices.
SimCardioTest is a 4-year project funded
by the European Commission that aims to
develop credible computer modelling and
simulation approaches on a cloud-based
platform for testing cardiac drugs and
devices in silico.This project has received funding from the
European Research Council (ERC) under the
European Union s Horizon 2020 research and
innovation programme under grant agreement
No. 101078351.Setzu, R.;Olivares, A.;Mill, J.;Albors, C.;Cámara, Ó.;Valen-Sendstad, K.;Mora-Fenoll, María Teresa... (2024). Building credibility of computational models in cardiovascular medicine through verification and validation. The Project Repository Journal. 19:86-90. https://doi.org/10.54050/PRJ1921403S86901
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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