The Experts below are selected from a list of 73110 Experts worldwide ranked by ideXlab platform
James H C Wang - One of the best experts on this subject based on the ideXlab platform.
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mechanobiological response of tendon stem cells implications of tendon homeostasis and pathogenesis of tendinopathy
Journal of Orthopaedic Research, 2010Co-Authors: Jianying Zhang, James H C WangAbstract:Tendons are constantly subjected to mechanical loading in vivo. Recently, stem cells were identified in human, mouse, and rabbit tendons, but the mechanobiological responses of tendon stem cells (TSCs) are still undefined. Using an in vitro system capable of mimicking in vivo loading conditions, it was determined that mechanical stretching increased TSC proliferation in a stretching magnitude-dependent manner. Moreover, low mechanical stretching at 4% (“clamp-to-clamp” Engineering Strain) promoted differentiation of TSCs into tenocytes, whereas large stretching at 8% induced differentiation of some TSCs into adipogenic, chondrogenic, and osteogenic lineages, as indicated by upregulated expression of marker genes for adipocytes, chondrocytes, and osteocytes. Thus, low mechanical stretching may be beneficial to tendons by enabling differentiation of TSCs into tenocytes to maintain tendon homeostasis. However, large mechanical loading may be detrimental, as it directs differentiation of TSCs into non-tenocytes in tendons, thus resulting in lipid accumulation, mucoid formation, and tissue calcification, which are typical features of tendinopathy at later stages. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:639–643, 2010
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mechanobiological response of tendon stem cells implications of tendon homeostasis and pathogenesis of tendinopathy
Journal of Orthopaedic Research, 2010Co-Authors: Jianying Zhang, James H C WangAbstract:Tendons are constantly subjected to mechanical loading in vivo. Recently, stem cells were identified in human, mouse, and rabbit tendons, but the mechanobiological responses of tendon stem cells (TSCs) are still undefined. Using an in vitro system capable of mimicking in vivo loading conditions, it was determined that mechanical stretching increased TSC proliferation in a stretching magnitude-dependent manner. Moreover, low mechanical stretching at 4% ("clamp-to-clamp" Engineering Strain) promoted differentiation of TSCs into tenocytes, whereas large stretching at 8% induced differentiation of some TSCs into adipogenic, chondrogenic, and osteogenic lineages, as indicated by upregulated expression of marker genes for adipocytes, chondrocytes, and osteocytes. Thus, low mechanical stretching may be beneficial to tendons by enabling differentiation of TSCs into tenocytes to maintain tendon homeostasis. However, large mechanical loading may be detrimental, as it directs differentiation of TSCs into non-tenocytes in tendons, thus resulting in lipid accumulation, mucoid formation, and tissue calcification, which are typical features of tendinopathy at later stages.
Gerlind Schubert - One of the best experts on this subject based on the ideXlab platform.
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equi biaxial tension tests on magneto rheological elastomers
Smart Materials and Structures, 2016Co-Authors: Gerlind Schubert, Philip G HarrisonAbstract:A bespoke test rig has been designed to facilitate testing of magneto-rheological (MR) elastomers (MREs) under equi-biaxial tension using a standard universal test machine. Tests were performed up to 10% Strain on both isotropic and anisotropic MREs with and without the application of an external magnetic field. Assumptions regarding the material's response were used to analyse stress–Strain results in the two stretching directions. The assumptions have been verified previously by uniaxial tension tests and by simulations of the magnetic flux distribution performed using a commercial multi-physics finite element software. The MR effect, which is defined as the increase in tangent modulus at a given Strain, has been studied versus Engineering Strain. The latter was measured optically in the experiments using a digital image correlation system. Relative MR effects up to 74% were found when the particle alignment of anisotropic MREs was oriented parallel to an applied magnetic induction of just 67.5 mT.
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large Strain behaviour of magneto rheological elastomers tested under uniaxial compression and tension and pure shear deformations
Polymer Testing, 2015Co-Authors: Gerlind SchubertAbstract:The large-Strain behaviour of Magneto-Rheological Elastomers (MREs) is characterised experimentally under uniaxial compression, uniaxial tension and pure shear deformation, in the absence and in the presence of magnetic fields. MREs are ‘smart’ materials that can alter their properties instantaneously by the application of external stimuli. They hold great potential for use in adaptive stiffness devices. So far, the large-Strain behaviour of MREs has not been well explored, and their behaviour under pure shear deformation has not been characterised. Tests on silicone rubber based isotropic and anisotropic MREs, with and without the application of an external magnetic field have been performed in this investigation. The MR effect, defined as the increase in tangent moduli, is studied versus large Engineering Strain. Strains were measured optically using a Digital Image Correlation (DIC) system. Relative MR effects up to 284% were found under uniaxial tension, when a magnetic field strength of 290 mT was applied with the loading direction parallel to the direction of particle alignment.
Jianying Zhang - One of the best experts on this subject based on the ideXlab platform.
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mechanobiological response of tendon stem cells implications of tendon homeostasis and pathogenesis of tendinopathy
Journal of Orthopaedic Research, 2010Co-Authors: Jianying Zhang, James H C WangAbstract:Tendons are constantly subjected to mechanical loading in vivo. Recently, stem cells were identified in human, mouse, and rabbit tendons, but the mechanobiological responses of tendon stem cells (TSCs) are still undefined. Using an in vitro system capable of mimicking in vivo loading conditions, it was determined that mechanical stretching increased TSC proliferation in a stretching magnitude-dependent manner. Moreover, low mechanical stretching at 4% (“clamp-to-clamp” Engineering Strain) promoted differentiation of TSCs into tenocytes, whereas large stretching at 8% induced differentiation of some TSCs into adipogenic, chondrogenic, and osteogenic lineages, as indicated by upregulated expression of marker genes for adipocytes, chondrocytes, and osteocytes. Thus, low mechanical stretching may be beneficial to tendons by enabling differentiation of TSCs into tenocytes to maintain tendon homeostasis. However, large mechanical loading may be detrimental, as it directs differentiation of TSCs into non-tenocytes in tendons, thus resulting in lipid accumulation, mucoid formation, and tissue calcification, which are typical features of tendinopathy at later stages. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:639–643, 2010
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mechanobiological response of tendon stem cells implications of tendon homeostasis and pathogenesis of tendinopathy
Journal of Orthopaedic Research, 2010Co-Authors: Jianying Zhang, James H C WangAbstract:Tendons are constantly subjected to mechanical loading in vivo. Recently, stem cells were identified in human, mouse, and rabbit tendons, but the mechanobiological responses of tendon stem cells (TSCs) are still undefined. Using an in vitro system capable of mimicking in vivo loading conditions, it was determined that mechanical stretching increased TSC proliferation in a stretching magnitude-dependent manner. Moreover, low mechanical stretching at 4% ("clamp-to-clamp" Engineering Strain) promoted differentiation of TSCs into tenocytes, whereas large stretching at 8% induced differentiation of some TSCs into adipogenic, chondrogenic, and osteogenic lineages, as indicated by upregulated expression of marker genes for adipocytes, chondrocytes, and osteocytes. Thus, low mechanical stretching may be beneficial to tendons by enabling differentiation of TSCs into tenocytes to maintain tendon homeostasis. However, large mechanical loading may be detrimental, as it directs differentiation of TSCs into non-tenocytes in tendons, thus resulting in lipid accumulation, mucoid formation, and tissue calcification, which are typical features of tendinopathy at later stages.
Tiejun Wang - One of the best experts on this subject based on the ideXlab platform.
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deformation response and constitutive modeling of pc abs and pc abs alloys under impact tensile loading
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Z N Yin, Tiejun WangAbstract:Abstract The objective of this paper is to experimentally study the tensile deformation behavior of the polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and PC/ABS alloys (with the blending ratio of PC to ABS being 80:20, 60:40, 50:50 and 40:60) at Strain rates 6.0 × 10 2 s −1 , 1.2 × 10 3 s −1 and 2.2 × 10 3 s −1 , respectively. The Split Hopkinson Tension Bar (SHTB) tests are carried out at room temperature (300 K) to characterize the Strain rate-dependent elastic, yielding and post-yielding deformation behavior. The curves of Engineering stress and Engineering Strain and true stress and true Strain are obtained for the PC, ABS and PC/ABS alloys at different Strain rates. The effects of Strain rate and the ABS fraction on the deformation behavior of PC, ABS and PC/ABS alloys are discussed in details, and then a Strain rate-dependent phenomenological constitutive model for PC, ABS and PC/ABS alloys is developed.
Mathieu Vanderhasten - One of the best experts on this subject based on the ideXlab platform.
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deformation mechanisms of ti 6al 4v during tensile behavior at low Strain rate
Journal of Materials Engineering and Performance, 2007Co-Authors: Mathieu Vanderhasten, L Rabet, Bert VerlindenAbstract:A superplastic Ti-6Al-4V grade has been deformed at a Strain rate of 5 × 10−4 s−1 and at temperatures up to 1050 °C. Structural mechanisms like grain boundary sliding, dynamic recrystallization, and dynamic grain growth, occurring during deformation, have been investigated and mechanical properties such as flow stress, Strain hardening, and Strain at rupture have been determined. Dynamic recrystallization (DRX) brings on a decrease in the grain size. This could be of great interest because a smaller grain size allows a decrease in temperature for superplastic forming. For DRX, the driving force present in the deformed microstructure must be high enough. This means the temperature must be sufficiently low to ensure storing of enough dislocation energy but must also be high enough to provide the activation energy needed for DRX and to allow superplastic deformation. The best compromise for the temperature was found to be situated at about 800 °C; this is quite a bit lower than the 925 °C referenced in the literature as the optimum for the superplastic deformation. At this medium temperature the Engineering Strain that could be reached exceeds 400%, a value high enough to ensure the industrial production of complex parts by the way of the superplastic forming. Microstructural, EBSD, and mechanical investigations were used to describe the observed mechanisms, some of which are concurrent.