This study characterized the impact of vein wall biomechanics on inflow diameter and luminal flow during venous angioplasty and stent placement, using postthrombotic and healthy biomechanical properties from an ovine venous stenosis and thrombosis model. Finite element analysis demonstrated more pronounced inflow channel narrowing in the postthrombotic vein compared with the healthy control vein during angioplasty and stent placement (relative inflow diameter reduction of 42% versus 13%, P < .0001). Computational fluid dynamics modeling showed increased relative areas of low wall shear rate in the postthrombotic vein compared with the normal vein (0.46 vs 0.24 for shear rate < 50 s; 0.13 vs 0.07 for shear rate < 15 s; P < .05), with flow stagnation and recirculation. Since inflow narrowing and low wall shear rate are associated with in-stent restenosis and reintervention, these computational results based on experimentally obtained biomechanical values highlight the significance of postthrombotic venous properties in optimizing venous intervention outcomes.
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http://dx.doi.org/10.1016/j.jvir.2021.12.006 | DOI Listing |
Background: Understanding site-related factors that influence enrolment within multicenter randomized controlled trials (RCT) may help reduce trial delays and cost over-runs and prevent early trial discontinuation. In this analysis of PROSPECT (Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial), we describe patient enrolment patterns and examine factors influencing site-based monthly enrolment.
Design: Retrospective analysis of a multicenter RCT.
To address the challenges of performing in-situ tests on riverbed overburden gravel, this study employs three scaling methods-equal mass substitution, similar gradation, and the mixed method-to investigate the original gradation of the gravel. Large-scale triaxial consolidated drained shear tests were conducted to evaluate the effects of the maximum particle size reduction ratio (M) and confining pressure on the stress-strain behavior, fractal dimension, particle breakage, and the parameters of the Duncan-Chang model (an elastic model describing nonlinear stress-strain relationships). The study explores how scaling, based on fractal dimension and particle breakage rate, impacts the strength and deformation characteristics of gravel materials.
View Article and Find Full Text PDFInt Endod J
December 2024
School of Dentistry, The University of Queensland, Brisbane, Queensland, Australia.
Aim: All commercial chelating gels contain EDTA which reacts chemically with sodium hypochlorite (NaOCl). This research aimed to develop a non-EDTA clodronate gel and to measure physicochemical and functional gel properties of the novel and commercial gels.
Methodology: A 1.
Gels
December 2024
Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum (East China), Ministry of Education, Qingdao 266580, China.
The utilization of CO foam gel fracturing fluid offers several significant advantages, including minimal reservoir damage, reduced water consumption during application, enhanced cleaning efficiency, and additional beneficial properties. However, several current CO foam gel fracturing fluid systems face challenges, such as complex preparation processes and insufficient viscosity, which limit their proppant transport capacity. To address these issues, this work develops a novel CO foam gel fracturing fluid system characterized by simple preparation and robust foam stability.
View Article and Find Full Text PDFGels
December 2024
Departamento de Ingeniería Química, Escuela Politécnica Superior, Universidad de Sevilla, E41011 Sevilla, Spain.
The main objective of this work is to investigate the influence of shear on the rheological properties and physical stability of aqueous dispersions of flaxseed fiber. The variable to consider will be the homogenization rate in two different rotor-stator homogenizers, Ultraturrax T50 or T25. In order to achieve the proposed objective, small amplitude oscillatory tests, flow curves, and multiple light scattering measurements were carried out.
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