Simulations of the ventricular flow patterns during left ventricular assist device (LVAD) support are mainly performed with idealized cylindrical inflow, neglecting the influence of the atrial vortex. In this study, the influence of the left atrium (LA) on the intra-ventricular flow was investigated via Computational Fluid Dynamics (CFD) simulations. Ventricular flow was simulated by a combined Eulerian (carrier flow)/Lagrangian (particles) approach taking into account either the LA or a cylindrical inflow section to mimic a fully support condition. The flow deviation at the mitral valve, the blood low-velocity volume as well as the residence time and shear stress history of the particles were calculated. Inclusion of the LA deflects the flow at the mitral valve by 25°, resulting in an asymmetric flow jet entering the left ventricle. This reduced the ventricular low-velocity volume by 40% (from 6.4 to 3.9 cm), increased (40%) the shear stress experienced by particles and correspondingly increased (27%) their residence time. Under the studied conditions, the atrial geometry plays a major role in the development of intraventricular flow patterns. A reliable prediction of blood flow dynamics and consequently thrombosis risk analysis within the ventricle requires the consideration of the LA in computational simulations.
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http://dx.doi.org/10.1177/03913988211056018 | DOI Listing |
Nat Commun
January 2025
Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA.
Ocean weather comprises vortical and straining mesoscale motions, which play fundamentally different roles in the ocean circulation and climate system. Vorticity determines the movement of major ocean currents and gyres. Strain contributes to frontogenesis and the deformation of water masses, driving much of the mixing and vertical transport in the upper ocean.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Basis Dis
January 2025
Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital of Hainan Medical University, No. 48 Baishuitang Road, Haikou City 570100, Hainan Province, China. Electronic address:
Background: Programmed cell death protein 5 (PDCD5) is involved in apoptosis and is regarded as a tumor suppressor in various tumors. However, its role and underlying molecular mechanisms in hepatocellular carcinoma (HCC) remain unclear.
Methods: PDCD5-overexpressing cell and xenograft tumor models were developed.
Mol Biol Evol
January 2025
UMR 8222 LECOB CNRS-Sorbonne Université, Observatoire Océanologique de Banyuls, Avenue du Fontaulé, 66650, Banyuls-sur-mer, France.
How the interplay of biotic and abiotic factors shapes current genetic diversity at the community level remains an open question, particularly in the deep sea. Comparative phylogeography of multiple species can reveal the influence of past climatic events, geographic barriers, and species life history traits on spatial patterns of genetic structure across lineages. To shed light on the factors that shape community-level genetic variation and to improve our understanding of deep-sea biogeographic patterns, we conducted a comparative population genomics study on seven hydrothermal vent species co-distributed in the Back-Arc Basins (BABs) of the Southwest Pacific region.
View Article and Find Full Text PDFJ Exp Biol
January 2025
Centre de Recherches sur la Cognition Animale, CNRS, Université Paul Sabatier, Toulouse 31062 cedex 09, France.
Solitary foraging insects like desert ants rely heavily on vision for navigation. While ants can learn visual scenes, it is unclear what cues they use to decide if a scene is worth exploring at the first place. To investigate this, we recorded the motor behavior of Cataglyphis velox ants navigating in a virtual reality set-up (VR) and measured their lateral oscillations in response to various unfamiliar visual scenes under both closed-loop and open-loop conditions.
View Article and Find Full Text PDFBrain Behav Immun Health
December 2024
Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1201 W. Gregory Dr., Urbana, IL, 61801, USA.
Respiratory infection by influenza A virus (IAV) is known to cause systemic inflammation, neuroinflammation, and cognitive impairment. We previously found that experimental infection with IAV affected oligodendrocyte homeostasis, which was associated with altered expression of genes involved in myelin maintenance as well as the lipidome. In this study, we sought to determine if clemastine, an antihistamine with myelin promoting properties, could reverse the effects of IAV on oligodendrocyte (OL) specific genes, as well as mitigate infection-induced cognitive impairment.
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