Based on a direct generalization of a proof given by Torquato for symmetry property in static regime, this express letter clarifies the reasons why the dynamic permeability tensor is symmetric for spatially periodic structures having symmetrical axes which do not coincide with orthogonal pairs being perpendicular to the axis of three-, four-, and sixfold symmetry. This somewhat nonintuitive property is illustrated by providing detailed numerical examples for a hexagonal lattice of solid cylinders in the asymptotic and frequency dependent regimes. It may be practically useful for numerical implementation validation and/or convergence assessment.
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http://dx.doi.org/10.1121/1.2968300 | DOI Listing |
Sci Rep
December 2024
Amsterdam Movement Sciences, Sports, Amsterdam, The Netherlands.
Repeated muscle micro-trauma may cause severe muscle damage. Diffusion tensor imaging (DTI) exhibits sensitivity to microstructural changes in skeletal muscle. We hypothesize that longer diffusion times enhance sensitivity to micro-trauma and that membrane permeability increases with micro-trauma.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
Introduction: Placental growth factor (PlGF) may regulate cerebrovascular permeability. We hypothesized that white matter interstitial fluid accumulation, estimated via magnetic resonance imaging (MRI) free water (FW), would explain the associations between elevated PlGF, white matter hyperintensities (WMH), and cognitive impairment.
Methods: MarkVCID consortium participants ≥55 years old with plasma PlGF and brain MRI were included.
Spine J
December 2024
Department of Orthopedic Surgery, The First Affiliated Hospital of Chongqing Medical University, No.1 Youyi Road, Yuzhong District, Chongqing 400016, China; Orthopedic Laboratory of Chongqing Medical University, No.1 Youyi Road, Yuzhong District, Chongqing 400016, China. Electronic address:
Background: After acute traumatic spinal cord injury (tSCI), various surgical strategies have been developed to alleviate elevated intraspinal pressure (ISP) and secondary injury.
Purpose: Our study aimed to investigate the impacts of duraplasty and laminectomy on edema progression, perfusion and functional outcomes after severe balloon compression SCI.
Study Design: In vivo animal study.
Background: The purpose of this study was to investigate the relationship between blood-brain barrier (BBB) permeability and cognitive functioning in healthy older adults and individuals with neurodegenerative diseases.
Methods And Results: A total of 124 participants with Alzheimer disease, cerebrovascular disease, or a mix Alzheimer's and cerebrovascular diseases and 55 controlparticipants underwent magnetic resonance imaging and neuropsychological testing. BBB permeability was measured with dynamic contrast-enhanced magnetic resonance imaging and white matter injury was measured using a quantitative diffusion-tensor imaging marker of white matter injury.
Materials (Basel)
June 2024
École Centrale Nantes, Nantes Université, CNRS, GeM, UMR 6183, F-44000 Nantes, France.
Permeability is a fundamental property of porous media. It quantifies the ease with which a fluid can flow under the effect of a pressure gradient in a network of connected pores. Porous materials can be natural, such as soil and rocks, or synthetic, such as a densified network of fibres or open-cell foams.
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