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https://www.readbyqxmd.com/read/28734257/comparison-of-femoropopliteal-artery-stents-under-axial-and-radial-compression-axial-tension-bending-and-torsion-deformations
#1
Kaspars Maleckis, Paul Deegan, William Poulson, Cole Sievers, Anastasia Desyatova, Jason MacTaggart, Alexey Kamenskiy
High failure rates of Peripheral Arterial Disease (PAD) stenting appear to be associated with the inability of certain stent designs to accommodate severe biomechanical environment of the femoropopliteal artery (FPA) that bends, twists, and axially compresses during limb flexion. Twelve Nitinol stents (Absolute Pro, Supera, Lifestent, Innova, Zilver, Smart Control, Smart Flex, EverFlex, Viabahn, Tigris, Misago, and Complete SE) were quasi-statically tested under bench-top axial and radial compression, axial tension, bending, and torsional deformations...
July 13, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28734256/3d-porous-polyurethanes-featured-by-different-mechanical-properties-characterization-and-interaction-with-skeletal-muscle-cells
#2
Lorenzo Vannozzi, Leonardo Ricotti, Tommaso Santaniello, Tercio Terencio, Reinier Oropesa-Nunez, Claudio Canale, Francesca Borghi, Arianna Menciassi, Cristina Lenardi, Irini Gerges
The fabrication of biomaterials for interaction with muscle cells has attracted significant interest in the last decades. However, 3D porous scaffolds featured by a relatively low stiffness (almost matching the natural muscle one) and highly stable in response to cyclic loadings are not available at present, in this context. This work describes 3D polyurethane-based porous scaffolds featured by different mechanical properties. Biomaterial stiffness was finely tuned by varying the cross-linking degree of the starting foam...
July 14, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28734117/hybrid-piezoresistive-optical-tactile-sensor-for-simultaneous-measurement-of-tissue-stiffness-and-detection-of-tissue-discontinuity-in-robot-assisted-minimally-invasive-surgery
#3
Naghmeh M Bandari, Roozbeh Ahmadi, Amir Hooshiar, Javad Dargahi, Muthukumaran Packirisamy
No abstract text is available yet for this article.
July 1, 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28731878/correlation-of-corneal-biomechanical-stiffness-with-refractive-error-and-ocular-biometry-in-a-pediatric-population
#4
Jyoti Matalia, Mathew Francis, Pooja Gogri, Pratibha Panmand, Himanshu Matalia, Abhijit Sinha Roy
PURPOSE: To assess the correlation between corneal biomechanical stiffness and refractive error (RE) in the pediatric population. METHODS: A total of 733 pediatric eyes were included in the study retrospectively. All eyes underwent corneal tomography (Pentacam), RE assessment, and air-puff deformation (Corvis-ST). Waveform analyses of deformation provided corneal stiffness (CS) and extraocular tissue stiffness (EOS). Eyes were subgrouped into emmetropia [manifest refraction spherical equivalent (MRSE) ∼ 0 D], hyperopia (MRSE > 0 D), myopia I (MRSE between 0 D and -3 D), myopia II (MRSE between -3 D and -6 D), and myopia III (MRSE greater than -6 D) for multivariate analyses...
July 19, 2017: Cornea
https://www.readbyqxmd.com/read/28731208/super-strong-super-stiff-macrofibers-with-aligned-long-bacterial-cellulose-nanofibers
#5
Sha Wang, Feng Jiang, Xu Xu, Yudi Kuang, Kun Fu, Emily Hitz, Liangbing Hu
With their impressive properties such as remarkable unit tensile strength, modulus, and resistance to heat, flame, and chemical agents that normally degrade conventional macrofibers, high-performance macrofibers are now widely used in various fields including aerospace, biomedical, civil engineering, construction, protective apparel, geotextile, and electronic areas. Those macrofibers with a diameter of tens to hundreds of micrometers are typically derived from polymers, gel spun fibers, modified carbon fibers, carbon-nanotube fibers, ceramic fibers, and synthetic vitreous fibers...
July 21, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28731083/mutable-polyelectrolyte-tube-arrays-mesoscale-modeling-and-lateral-force-microscopy
#6
Steven W Cranford, Lin Han, Christine Ortiz, Markus J Buehler
In this study, the pH-dependent friction of layer-by-layer assemblies of poly(allylamine hydrochloride) and poly(acrylic acid) (PAH/PAA) are quantified for microtube array structures via experimental and simulated lateral force microscopy (LFM). A novel coarse-grain tube model is developed, utilizing a molecular dynamics (MD) framework with a Hertzian soft contact potential (such that F ∼ δ(3/2)) to allow the efficient dynamic simulation of 3D arrays consisting of hundreds of tubes at micrometer length scales...
July 21, 2017: Soft Matter
https://www.readbyqxmd.com/read/28729696/effects-of-cardiac-timing-and-peripheral-resistance-on-measurement-of-pulse-wave-velocity-for-assessment-of-arterial-stiffness
#7
Hanguang Xiao, Mark Butlin, Isabella Tan, Alberto Avolio
To investigate the effects of heart rate (HR), left ventricular ejection time (LVET) and wave reflection on arterial stiffness as assessed by pulse wave velocity (PWV), a pulse wave propagation simulation system (PWPSim) based on the transmission line model of the arterial tree was developed and was applied to investigate pulse wave propagation. HR, LVET, arterial elastic modulus and peripheral resistance were increased from 60 to 100 beats per minute (bpm), 0.1 to 0.45 seconds, 0.5 to 1.5 times and 0.5 to 1...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28729605/evaluating-the-effects-of-material-properties-of-artificial-meniscal-implant-in-the-human-knee-joint-using-finite-element-analysis
#8
Duraisamy Shriram, Gideon Praveen Kumar, Fangsen Cui, Yee Han Dave Lee, Karupppasamy Subburaj
Artificial meniscal implants may replace severely injured meniscus and restore the normal functionality of the knee joint. Implant material stiffness and shape influence the longevity of implantations. This study, using 3D finite element analysis, aimed to evaluate the effects of material stiffness variations of anatomically shaped artificial meniscal implant in the knee joint. Finite element simulations were conducted on five different cases including intact knee, medial meniscectomized knee, and the knee joint with the meniscal implant with three distinct material stiffness...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28728959/mechanisms-contributing-to-gait-speed-and-metabolic-cost-in-children-with-unilateral-cerebral-palsy
#9
Tatiana Pessoa Silva Pinto, Sérgio Teixeira Fonseca, Rejane Vale Gonçalves, Thales Rezende Souza, Daniela Virgínia Vaz, Paula Lanna Pereira Silva, Marisa Cotta Mancini
BACKGROUND: Gait speed and metabolic cost are indicators of functional capacity in children with cerebral palsy. Uncovering their mechanisms helps guide therapeutic actions. OBJECTIVES: To investigate the contributions of energy-generating and energy-conserving mechanisms to gait speed and metabolic cost of children with unilateral cerebral palsy. METHODS: Data on eccentric and concentric muscle work, co-contraction, elastic torque and vertical stiffness of the affected-limb, forcing torque of the non-affected limb, gait speed and metabolic cost were collected from 14 children with unilateral cerebral palsy, aged 6-12 years...
July 5, 2017: Brazilian Journal of Physical Therapy
https://www.readbyqxmd.com/read/28728927/hcv-infected-and-hiv-hcv-co-infected-individuals-treated-with-direct-acting-antivirals-to-what-extent-do-they-differ
#10
Giuseppe Bruno, Annalisa Saracino, Luigia Scudeller, Claudia Fabrizio, Raffaele Dell'Acqua, Eugenio Milano, Michele Milella, Nicoletta Ladisa, Laura Monno, Gioacchino Angarano
BACKGROUND AND AIMS: DAA-based anti-HCV treatment has been associated with high rates of sustained virological response (SVR) and good tolerability in clinical randomized trials. To assess safety and effectiveness of DAAs in both HCV mono-infected and HIV/HCV co-infected patients. METHODS: All consecutive HCV-infected patients, including HIV/HCV co-infected, receiving DAA-based treatment from February 2015 until September 2016 in our Clinic, were included. Clinical, virological and biochemical data were retrieved...
July 17, 2017: International Journal of Infectious Diseases: IJID
https://www.readbyqxmd.com/read/28728866/deformability-and-size-based-microcapsule-sorting
#11
Doriane Vesperini, Oriane Chaput, Nadège Munier, Pauline Maire, Florence Edwards-Lévy, Anne-Virginie Salsac, Anne Le Goff
Biomedical applications often require to sort cells according to their physical properties, such as size, density or deformability. In recent years, microfluidics has provided a variety of tools to sort micro-objects. We present here a simple microfluidic device consisting of a channel containing a semi-cylindrical obstacle against which capsules are squeezed by the flow, followed by a diverging chamber where streamlines separate. We demonstrate that this basic system is capable of sorting elastic microcapsules according to their size at low flow strength, and according to the stiffness of their membrane at high flow strength...
July 17, 2017: Medical Engineering & Physics
https://www.readbyqxmd.com/read/28728814/a-tour-de-force-the-discovery-properties-and-function-of-piezo-channels
#12
P A Gottlieb
Mechanical transducers appear throughout cell biology and are used to convert mechanical stress into chemical or electrical signals that allow the cell to respond to environmental changes. In the past six years, a eukaryotic mechanical channel family with two members, Piezo1 and Piezo2, has been identified. Piezo1 was shown to be a cation-selective channel that does not require ancillary proteins for activity. Mouse Piezo1 is large, with over 2500 amino acids, and is not homologous to other ion channels. Both piezo channels have rapid voltage-dependent inactivation with a reversal potential near 0mV...
2017: Current Topics in Membranes
https://www.readbyqxmd.com/read/28728790/a-mechanistic-damage-model-for-ligaments
#13
Jeff M Barrett, Jack P Callaghan
PURPOSE: The accuracy of biomechanical models is predicated on the realism by which they represent their biomechanical tissues. Unfortunately, most models use phenomenological ligament models that neglect the behaviour in the failure region. Therefore, the purpose of this investigation was to test whether a mechanistic model of ligamentous tissue portrays behaviour representative of actual ligament failure tests. MODEL: The model tracks the time-evolution of a population of collagen fibres in a theoretical ligament...
July 11, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28728780/detecting-regional-stiffness-changes-in-aortic-aneurysmal-geometries-using-pressure-normalized-strain
#14
Doran S Mix, Ling Yang, Camille C Johnson, Nathan Couper, Ben Zarras, Isaac Arabadjis, Lauren E Trakimas, Michael C Stoner, Steven W Day, Michael S Richards
Transabdominal ultrasound elasticity imaging could improve the assessment of rupture risk for abdominal aortic aneurysms by providing information on the mechanical properties and stress or strain states of vessel walls. We implemented a non-rigid image registration method to visualize the pressure-normalized strain within vascular tissues and adapted it to measure total strain over an entire cardiac cycle. We validated the algorithm's performance with both simulated ultrasound images with known principal strains and anatomically accurate heterogeneous polyvinyl alcohol cryogel vessel phantoms...
July 17, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28728487/feasibility-and-characteristics-of-arterial-stiffness-measurement-in-preschool-children
#15
Maaike M Vanderschuren, Cuno Spm Uiterwaal, Cornelis K van der Ent, Jacobien B Eising
Background Arterial stiffness is an important predictor of cardiovascular risk in adult life. Increased arterial stiffness can also be present in children and may be associated with several other cardiovascular risk factors. Until now, however, we know little about measuring arterial stiffness in preschool children. In this study, we assessed the feasibility of measuring arterial stiffness in preschool children and explored possible determinants related to arterial stiffness at this age. Methods We studied 168 healthy children, aged 3...
January 1, 2017: European Journal of Preventive Cardiology
https://www.readbyqxmd.com/read/28728486/relationship-between-neck-circumference-insulin-resistance-and-arterial-stiffness-in-overweight-and-obese-subjects
#16
Francesco Fantin, Gabriele Comellato, Andrea P Rossi, Elisa Grison, Elena Zoico, Gloria Mazzali, Mauro Zamboni
Background Only a few studies have investigated the relationship between neck circumference and cardiometabolic risk. The aim of this study was to assess the relationships between neck circumference, waist circumference, metabolic variables and arterial stiffness in a group of overweight and obese subjects evaluating a possible independent role of neck circumference in determining arterial stiffness. Methods and results We studied 95 subjects (53 women) with an age range of 20-77 years and body mass index range from 25...
January 1, 2017: European Journal of Preventive Cardiology
https://www.readbyqxmd.com/read/28728481/feasibility-of-two-dimensional-speckle-tracking-in-evaluation-of-arterial-stiffness-comparison-with-pulse-wave-velocity-and-conventional-sonographic-markers-of-atherosclerosis
#17
Michał Podgórski, Piotr Grzelak, Magdalena Kaczmarska, Michał Polguj, Maciej Łukaszewski, Ludomir Stefańczyk
Objective Arterial stiffening is an early marker of atherosclerosis that has a prognostic value for cardiovascular morbidity and mortality. Although many markers of arterial hardening have been proposed, the search is on for newer, more user-friendly and reliable surrogates. One such potential candidate has emerged from cardiology, the speckle-tracking technique. The aim of this study was to evaluate the feasibility of the two-dimensional speckle tracking for the evaluation of arterial wall stiffness in comparison with standard stiffness parameters...
January 1, 2017: Vascular
https://www.readbyqxmd.com/read/28727753/a-prospective-cohort-study-on-risk-factors-of-musculoskeletal-complaints-pain-and-or-stiffness-in-a-general-population-the-troms%C3%A3-study
#18
Ole Fredrik Andorsen, Luai Awad Ahmed, Nina Emaus, Elise Klouman
BACKGROUND: Female gender has been associated with musculoskeletal complaints (MSCs), but there are limited studies on how other factors may influence women and men differently. The aim of this prospective cohort study was to explore possible predictors of MSCs in women and men free of MSCs at baseline. METHODS: The present study included participants from the population-based Tromsø study, with baseline data from 1994-1995 and follow-up data from 2007-2008. MSCs were defined as having pain and/or stiffness in muscles and joints for 3 consecutive months during the past year...
2017: PloS One
https://www.readbyqxmd.com/read/28727585/closed-continuous-irrigation-with-lidocaine-and-immediate-mobilization-for-treatment-of-pyogenic-tenosynovitis
#19
Rebecca Knackstedt, Joyce Tyler, Steven Bernard
Pyogenic flexor tenosynovitis treatment consists of either closed continuous irrigation with sterile saline or antibiotic solution, or open debridement and irrigation. These treatment approaches serve to resolve the infection, but are extremely painful and residual stiffness can be devastating to the patient. We describe herein our approach to managing pyogenic flexor tenosynovitis. To provide continuous irrigation, a butterfly catheter with needle removed is utilized with irrigation holes cut into the tubing...
July 19, 2017: Techniques in Hand & Upper Extremity Surgery
https://www.readbyqxmd.com/read/28727323/indocyanine-green-near-infrared-lymphangiography-for-evaluation-of-effectiveness-of-edema-fluid-flow-under-therapeutic-compression
#20
Marzanna T Zaleska, Waldemar L Olszewski
The commonly used modalities for therapy of limb lymphedema are manual lymphatic drainage, manual devices moving edema fluid and intermittent pneumatic compression (IPC). What seems to be necessary for validation of the effect of the compression procedure is imaging of the mobilized moving edema fluid. Picture of edema fluid flow would allow the therapist to use force adjusted to the tissue volume and stiffness differing in various limb regions as well as identify sites of abundant accumulation of fluid requiring more compression...
July 20, 2017: Journal of Biophotonics
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