Guided wave propagation has recently drawn significant interest in the ultrasonic characterization of bone. In this work, we present a two-dimensional computational study of ultrasound propagation in healing bones aiming at monitoring the fracture healing process. In particular, we address the effect of fluid loading boundary conditions on the characteristics of guided wave propagation, using both time and time-frequency (t-f) signal analysis techniques, for three study cases. In the first case, the bone was assumed immersed in blood which occupied the semi-infinite spaces of the upper and lower surfaces of the plate. In the second case, the bone model was assumed to have the upper surface loaded by a 2mm thick layer of blood and the lower surface loaded by a semi-infinite fluid with properties close to those of bone marrow. The third case, involves a three-layer model in which the upper surface of the plate was again loaded by a layer of blood, whereas the lower surface was loaded by a 2mm layer of a fluid which simulated bone marrow. The callus tissue was modeled as an inhomogeneous material and fracture healing was simulated as a three-stage process. The results clearly indicate that the application of realistic boundary conditions has a significant effect on the dispersion of guided waves when compared to simplified models in which the bone's surfaces are assumed free.
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http://dx.doi.org/10.1016/j.ultras.2008.04.013 | DOI Listing |
J Exp Psychol Hum Percept Perform
January 2025
School of Psychology, University of Leeds.
Multi-item retro-cueing effects refer to better working memory performance for multiple items when they are cued after their offset compared to a neutral condition in which all items are cued. However, several studies have reported boundary conditions, and findings have also sometimes failed to replicate. We hypothesized that a strategy to focus on only one of the cued items could possibly yield these inconsistent patterns.
View Article and Find Full Text PDFJ Health Organ Manag
January 2025
Department of Quality, Safety and Clinical Adoption, University Health Network, Toronto, Canada.
Purpose: Despite robust quality improvement efforts in healthcare, learning from patient safety incidents remains difficult. Our study explores counter-vailing powers shaping learning processes and possibilities in healthcare organizations, with a focus on social, political and organizational dynamics of learning.
Design/methodology/approach: Deploying concepts of situated curriculum, boundary work and interconnected knowledge practices, we interviewed staff and physicians ( = 15) in a large Academic Health Science Centre in Canada about their experiences of incident investigations and resultant information sharing.
SICOT J
January 2025
Department of Orthopaedic Surgery, Joint Replacement Unit, Kuala Lumpur Hospital, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia.
Introduction: Extraarticular deformity (EAD) with knee arthritis is a complex condition involving tri-planar bone deformity with pathological malalignment and chronic soft tissue contracture or laxity in the knee joint. Intraarticular correction by TKA, which was previously performed with conventional manual jig by mechanical alignment technique, had its limits and difficulties especially extensive soft tissue release and risk of jeopardizing the collateral ligaments. Robotic technology allows for reproducible and precise execution of surgical plan and allows adjustment to various new personalised alignment philosophy including functional alignment (FA).
View Article and Find Full Text PDFInt J Occup Saf Ergon
January 2025
College of Fashion and Design, Donghua University, China.
In wildland firefighting, the air gap (AG) between clothing and the human body can effectively decrease heat transferred to skin but has a negative impact on thermal aging of clothing. Heat transfer to skin from a fire source can led to burn injuries and heat is transmitted between adjacent AGs parallel to the skin surface. An open AG simulator was developed to explore the dual effects of the AG on fabric thermal aging and skin thermal protection.
View Article and Find Full Text PDFPharmacol Res
January 2025
College of Biological and Food Engineering, Qujing Normal University, 655011, Qujing, Yunnan, China. Electronic address:
The hallmarks of aging encompass a variety of molecular categories (genomic, telomeric, and epigenetic), organelles (proteostasis, autophagy, and mitochondria), cellular components (including stem cells), systems (such as intercellular communication and chronic inflammation), and environmental factors (dysbiosis and nutrient sensing). These hallmarks play a crucial role in the aging process. Despite their intricate interconnections, the relationships among the hallmarks of aging remain unclear.
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