The Experts below are selected from a list of 16224 Experts worldwide ranked by ideXlab platform
Rachel E B Watson - One of the best experts on this subject based on the ideXlab platform.
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ageing significantly impacts the Biomechanical Function and structural composition of skin
Experimental Dermatology, 2019Co-Authors: Abigail K Langton, Christopher E M Griffiths, Helen K Graham, Rachel E B WatsonAbstract:Skin ageing is a complex process involving the additive effects of skin's interaction with its external environment, predominantly chronic sun exposure, upon a background of time-dependent intrinsic ageing. Here, using non-invasive cutometry and ballistometry, we explore the consequences of ageing on the Biomechanical Function of skin in otherwise healthy White Northern European volunteers. Intrinsic skin ageing caused Biomechanical decline; skin loses both resilience (P < 0.01) and elasticity (P < 0.001), which is characterised histologically by modest effacement of rete ridges (P < 0.05) and disorganisation of papillary dermal elastic fibres. At photoexposed sites, Biomechanical testing identified significant loss of Biomechanical Function-particularly in the aged cohort. Photoaged forearm displayed severe loss of resilience (P < 0.001) and elasticity (P < 0.001); furthermore with repetitive testing, fatigue (P < 0.001), hysteresis (P < 0.001) and viscous "creep" (P < 0.001) were exacerbated. Histologically, both young and aged forearm displayed flattening of rete ridges and disruption to the arrangement of elastic fibres. We conclude that maintenance of skin architecture is inherently associated with optimal Biomechanical properties. Modest perturbations to skin architecture-as exemplified by intrinsic ageing-result in moderate Functional decline. Chronic sun exposure causes fundamental changes to the clinical and histological appearance of skin, and these are reflected by an extreme alteration in Biomechanical Function.
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Ageing significantly impacts the Biomechanical Function and structural composition of skin
Experimental dermatology, 2019Co-Authors: Abigail K Langton, Christopher E M Griffiths, Helen K Graham, Rachel E B WatsonAbstract:Skin ageing is a complex process involving the additive effects of skin's interaction with its external environment, predominantly chronic sun exposure, upon a background of time-dependent intrinsic ageing. Here, using non-invasive cutometry and ballistometry, we explore the consequences of ageing on the Biomechanical Function of skin in otherwise healthy White Northern European volunteers. Intrinsic skin ageing caused Biomechanical decline; skin loses both resilience (P
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aging in skin of color disruption to elastic fiber organization is detrimental to skin s Biomechanical Function
Journal of Investigative Dermatology, 2019Co-Authors: A K Langton, A.l. Chien, Sabrina Alessi, Mark Hann, Sewon Kang, Christopher E M Griffiths, Rachel E B WatsonAbstract:Skin aging is a complex process involving the additive effects of time-dependent intrinsic aging and changes elicited via skin's interaction with the environment. Maintaining optimal skin Function is essential for healthy aging across global populations; yet most research focuses on lightly pigmented skin (Fitzpatrick phototypes I-III), with little emphasis on skin of color (Fitzpatrick phototypes V-VI). Here, we explore the Biomechanical and histologic consequences of aging in black African-American volunteers. We found that healthy young buttock and dorsal forearm skin was Biomechanically resilient, highly elastic, and characterized histologically by strong interdigitation of rete ridges, abundant organized fibrillar collagen, and plentiful arrays of elastic fibers. In contrast, intrinsically aged buttock skin was significantly less resilient, less elastic, and was accompanied by effacement of rete ridges with reduced deposition of both elastic fibers and fibrillar collagens. In chronically photoexposed dorsal forearm, significant impairment of all Biomechanical Functions was identified, with complete flattening of rete ridges and marked depletion of elastic fibers and fibrillar collagens. We conclude that in skin of color, both intrinsic aging and photoaging significantly impact skin Function and composition, despite the additional photoprotective properties of increased melanin. Improved public health advice regarding the consequences of chronic photoexposure and the importance of multimodal photoprotection use for all is of global significance.
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Aging in Skin of Color: Disruption to Elastic Fiber Organization Is Detrimental to Skin’s Biomechanical Function
Journal of Investigative Dermatology, 2018Co-Authors: A K Langton, A.l. Chien, Sabrina Alessi, Mark Hann, Sewon Kang, Christopher E M Griffiths, Rachel E B WatsonAbstract:Skin aging is a complex process involving the additive effects of time-dependent intrinsic aging and changes elicited via skin’s interaction with the environment. Maintaining optimal skin Function is essential for healthy aging across global populations; yet most research focuses on lightly pigmented skin (Fitzpatrick phototypes I–III), with little emphasis on skin of color (Fitzpatrick phototypes V–VI). Here, we explore the Biomechanical and histologic consequences of aging in black African-American volunteers. We found that healthy young buttock and dorsal forearm skin was Biomechanically resilient, highly elastic, and characterized histologically by strong interdigitation of rete ridges, abundant organized fibrillar collagen, and plentiful arrays of elastic fibers. In contrast, intrinsically aged buttock skin was significantly less resilient, less elastic, and was accompanied by effacement of rete ridges with reduced deposition of both elastic fibers and fibrillar collagens. In chronically photoexposed dorsal forearm, significant impairment of all Biomechanical Functions was identified, with complete flattening of rete ridges and marked depletion of elastic fibers and fibrillar collagens. We conclude that in skin of color, both intrinsic aging and photoaging significantly impact skin Function and composition, despite the additional photoprotective properties of increased melanin. Improved public health advice regarding the consequences of chronic photoexposure and the importance of multimodal photoprotection use for all is of global significance.
David A. Vorp - One of the best experts on this subject based on the ideXlab platform.
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Biomechanical characterization of the urethral musculature
American journal of physiology. Renal physiology, 2005Co-Authors: Ron J. Jankowski, Rachelle L. Prantil, Michael B. Chancellor, William C. De Groat, Johnny Huard, David A. VorpAbstract:Rigorous study of the associations between urethral structural anatomy and Biomechanical Function is necessary to advance the understanding of the development, progression, and treatment of urethra...
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Development of an experimental system for the study of urethral Biomechanical Function
American journal of physiology. Renal physiology, 2003Co-Authors: Ron J. Jankowski, Rachelle L. Prantil, Matthew O. Fraser, Michael B. Chancellor, William C. De Groat, Johnny Huard, David A. VorpAbstract:Despite its principal mechanical Function in the storage and release of urine, the Biomechanical properties of the urethra have remained largely unexplored. The purpose of this study was to develop and validate an experimental model that can be used for evaluating whole urethral tissue in such a manner. Bladder-urethral specimens were excised from halothane-anesthetized female rats and mounted at in vivo length within the experimental apparatus consisting of a tissue perfusion chamber, an adjustable fluid column, and a laser micrometer. Outer diameter measurements were made at proximal, mid, and distal axial locations in response to increases in intraluminal pressure and after addition of various muscle-responsive agents. Basal smooth muscle tone and regional variations in compliance were detected through pressure-diameter responses. Chemically evoked contractile responses were measured and correspond to regional compositions of intrinsic smooth and striated muscle components. The results presented illustrate the utility of this system, which should permit a more thorough characterization of structure-Function relationships and urethral Biomechanical Function in relation to normal and dysFunctional tissue states.
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Establishing a system for the study of urethral Biomechanical Function
Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and, 1Co-Authors: Ron J. Jankowski, Rachelle L. Prantil, Matthew O. Fraser, Michael B. Chancellor, David A. Vorp, Kazumasa Torimoto, Johnny HuardAbstract:By applying experimental concepts and principles originally established in the study of blood vessel biomechanics, we are exploring various aspects of lower urinary tract Function, dysFunction, and treatment effects on tissue properties and performance. We demonstrate here the feasibility of using a modified ex vivo vascular perfusion apparatus for urethral Functional studies. Through administration of various pharmacologic agents, and against applied luminal pressures, we demonstrate control over urethral smooth and striated muscle contractile elements. The ability to measure such physiologic responses provides the basis for performing novel Functional studies pertaining to the role of each component in overall urethral Function and biomechanics. Therefore, the use of this system to evaluate ex vivo physiology and Biomechanical properties will advance the understanding of underlying principles of both normal and abnormal urethral Function.
Chung-hao Lee - One of the best experts on this subject based on the ideXlab platform.
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A pilot in silico modeling-based study of the pathological effects on the Biomechanical Function of tricuspid valves.
International journal for numerical methods in biomedical engineering, 2020Co-Authors: Devin W. Laurence, Emily L. Johnson, Ming-chen Hsu, Ryan Baumwart, Arshid Mir, Harold M. Burkhart, Gerhard A. Holzapfel, Chung-hao LeeAbstract:Current clinical assessment of Functional tricuspid valve regurgitation relies on metrics quantified from medical imaging modalities. Although these clinical methodologies are generally successful, the lack of detailed information about the mechanical environment of the valve presents inherent challenges for assessing tricuspid valve regurgitation. In the present study, we have developed a finite element-based in silico model of one porcine tricuspid valve (TV) geometry to investigate how various pathological conditions affect the overall Biomechanical Function of the TV. There were three primary observations from our results. Firstly, the results of the papillary muscle (PM) displacement study scenario indicated more pronounced changes in the TV Biomechanical Function. Secondly, compared to uniform annulus dilation, nonuniform dilation scenario induced more evident changes in the von Mises stresses (83.8-125.3 kPa vs 65.1-84.0 kPa) and the Green-Lagrange strains (0.52-0.58 vs 0.47-0.53) for the three TV leaflets. Finally, results from the pulmonary hypertension study scenario showed opposite trends compared to the PM displacement and annulus dilation scenarios. Furthermore, various chordae rupture scenarios were simulated, and the results showed that the chordae tendineae attached to the TV anterior and septal leaflets may be more critical to proper TV Function. This in silico modeling-based study has provided a deeper insight into the tricuspid valve pathologies that may be useful, with moderate extensions, for guiding clinical decisions. NOVELTY STATEMENT: The novelties of the research are summarized below: A comprehensive in silico pilot study of how isolated Functional tricuspid regurgitation pathologies and ruptured chordae tendineae would alter the tricuspid valve Function; An extensive analysis of the tricuspid valve Function, including mechanical quantities (eg, the von Mises stress and the Green-Lagrange strain) and clinically-relevant geometry metrics (eg, the tenting area and the coaptation height); and A developed computational modeling pipeline that can be extended to evaluate patient-specific tricuspid valve geometries and enhance the current clinical diagnosis and treatment of tricuspid regurgitation.
Gemma Marie Whatling - One of the best experts on this subject based on the ideXlab platform.
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what is the relationship between knee Biomechanical Function and patient reported Function before and after total knee replacement
Orthopaedic Proceedings, 2018Co-Authors: Lucy Bailey, Paul Biggs, Christopher G. Wilson, Catherine Avril Holt, Gemma Marie WhatlingAbstract:Risk factors for poor outcomes after total knee replacement (TKR) have been identified, but the underlying causes are not fully understood. The aim of this research was to establish the relationship between measurable gait parameters and patients' subjective Function, pre and post total knee replacement. 25 subjects underwent gait analysis, before and one year following total knee replacement. Patient reported Function was investigated using the Activities of Daily Living Scale of the Knee Outcome Survey (KOS). Gait analysis was performed using infrared cameras and reflective marker clusters. Correlation between motion analysis data and patient reported Function was investigate. Whilst multiple gait parameters correlated with KOS score preoperatively, there was no correlation after TKR. Three preoperative measurements correlated with the improvement in score a subject achieved following surgery: These were preoperative rate of extension in swing, total range of flexion from heel strike and time point of m...
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WHAT IS THE RELATIONSHIP BETWEEN KNEE Biomechanical Function AND PATIENT REPORTED Function BEFORE AND AFTER TOTAL KNEE REPLACEMENT
Journal of Bone and Joint Surgery-british Volume, 2015Co-Authors: Lucy Bailey, Paul Biggs, Christopher G. Wilson, Catherine Avril Holt, Gemma Marie WhatlingAbstract:Risk factors for poor outcomes after total knee replacement (TKR) have been identified, but the underlying causes are not fully understood. The aim of this research was to establish the relationship between measurable gait parameters and patients9 subjective Function, pre and post total knee replacement. 25 subjects underwent gait analysis, before and one year following total knee replacement. Patient reported Function was investigated using the Activities of Daily Living Scale of the Knee Outcome Survey (KOS). Gait analysis was performed using infrared cameras and reflective marker clusters. Correlation between motion analysis data and patient reported Function was investigate. Whilst multiple gait parameters correlated with KOS score preoperatively, there was no correlation after TKR. Three preoperative measurements correlated with the improvement in score a subject achieved following surgery: These were preoperative rate of extension in swing, total range of flexion from heel strike and time point of maximum stance extension. Our results suggest that whilst preoperatively there is a close relationship between knee Biomechanical Function and patient reported Function, after TKR factors other than Biomechanical Function determine patient outcomes.
Christopher E M Griffiths - One of the best experts on this subject based on the ideXlab platform.
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ageing significantly impacts the Biomechanical Function and structural composition of skin
Experimental Dermatology, 2019Co-Authors: Abigail K Langton, Christopher E M Griffiths, Helen K Graham, Rachel E B WatsonAbstract:Skin ageing is a complex process involving the additive effects of skin's interaction with its external environment, predominantly chronic sun exposure, upon a background of time-dependent intrinsic ageing. Here, using non-invasive cutometry and ballistometry, we explore the consequences of ageing on the Biomechanical Function of skin in otherwise healthy White Northern European volunteers. Intrinsic skin ageing caused Biomechanical decline; skin loses both resilience (P < 0.01) and elasticity (P < 0.001), which is characterised histologically by modest effacement of rete ridges (P < 0.05) and disorganisation of papillary dermal elastic fibres. At photoexposed sites, Biomechanical testing identified significant loss of Biomechanical Function-particularly in the aged cohort. Photoaged forearm displayed severe loss of resilience (P < 0.001) and elasticity (P < 0.001); furthermore with repetitive testing, fatigue (P < 0.001), hysteresis (P < 0.001) and viscous "creep" (P < 0.001) were exacerbated. Histologically, both young and aged forearm displayed flattening of rete ridges and disruption to the arrangement of elastic fibres. We conclude that maintenance of skin architecture is inherently associated with optimal Biomechanical properties. Modest perturbations to skin architecture-as exemplified by intrinsic ageing-result in moderate Functional decline. Chronic sun exposure causes fundamental changes to the clinical and histological appearance of skin, and these are reflected by an extreme alteration in Biomechanical Function.
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Ageing significantly impacts the Biomechanical Function and structural composition of skin
Experimental dermatology, 2019Co-Authors: Abigail K Langton, Christopher E M Griffiths, Helen K Graham, Rachel E B WatsonAbstract:Skin ageing is a complex process involving the additive effects of skin's interaction with its external environment, predominantly chronic sun exposure, upon a background of time-dependent intrinsic ageing. Here, using non-invasive cutometry and ballistometry, we explore the consequences of ageing on the Biomechanical Function of skin in otherwise healthy White Northern European volunteers. Intrinsic skin ageing caused Biomechanical decline; skin loses both resilience (P
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aging in skin of color disruption to elastic fiber organization is detrimental to skin s Biomechanical Function
Journal of Investigative Dermatology, 2019Co-Authors: A K Langton, A.l. Chien, Sabrina Alessi, Mark Hann, Sewon Kang, Christopher E M Griffiths, Rachel E B WatsonAbstract:Skin aging is a complex process involving the additive effects of time-dependent intrinsic aging and changes elicited via skin's interaction with the environment. Maintaining optimal skin Function is essential for healthy aging across global populations; yet most research focuses on lightly pigmented skin (Fitzpatrick phototypes I-III), with little emphasis on skin of color (Fitzpatrick phototypes V-VI). Here, we explore the Biomechanical and histologic consequences of aging in black African-American volunteers. We found that healthy young buttock and dorsal forearm skin was Biomechanically resilient, highly elastic, and characterized histologically by strong interdigitation of rete ridges, abundant organized fibrillar collagen, and plentiful arrays of elastic fibers. In contrast, intrinsically aged buttock skin was significantly less resilient, less elastic, and was accompanied by effacement of rete ridges with reduced deposition of both elastic fibers and fibrillar collagens. In chronically photoexposed dorsal forearm, significant impairment of all Biomechanical Functions was identified, with complete flattening of rete ridges and marked depletion of elastic fibers and fibrillar collagens. We conclude that in skin of color, both intrinsic aging and photoaging significantly impact skin Function and composition, despite the additional photoprotective properties of increased melanin. Improved public health advice regarding the consequences of chronic photoexposure and the importance of multimodal photoprotection use for all is of global significance.
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Aging in Skin of Color: Disruption to Elastic Fiber Organization Is Detrimental to Skin’s Biomechanical Function
Journal of Investigative Dermatology, 2018Co-Authors: A K Langton, A.l. Chien, Sabrina Alessi, Mark Hann, Sewon Kang, Christopher E M Griffiths, Rachel E B WatsonAbstract:Skin aging is a complex process involving the additive effects of time-dependent intrinsic aging and changes elicited via skin’s interaction with the environment. Maintaining optimal skin Function is essential for healthy aging across global populations; yet most research focuses on lightly pigmented skin (Fitzpatrick phototypes I–III), with little emphasis on skin of color (Fitzpatrick phototypes V–VI). Here, we explore the Biomechanical and histologic consequences of aging in black African-American volunteers. We found that healthy young buttock and dorsal forearm skin was Biomechanically resilient, highly elastic, and characterized histologically by strong interdigitation of rete ridges, abundant organized fibrillar collagen, and plentiful arrays of elastic fibers. In contrast, intrinsically aged buttock skin was significantly less resilient, less elastic, and was accompanied by effacement of rete ridges with reduced deposition of both elastic fibers and fibrillar collagens. In chronically photoexposed dorsal forearm, significant impairment of all Biomechanical Functions was identified, with complete flattening of rete ridges and marked depletion of elastic fibers and fibrillar collagens. We conclude that in skin of color, both intrinsic aging and photoaging significantly impact skin Function and composition, despite the additional photoprotective properties of increased melanin. Improved public health advice regarding the consequences of chronic photoexposure and the importance of multimodal photoprotection use for all is of global significance.