The Experts below are selected from a list of 80280 Experts worldwide ranked by ideXlab platform
Scott C Wearing - One of the best experts on this subject based on the ideXlab platform.
-
lower Material Stiffness in rupture repaired achilles tendon during walking transmission mode ultrasound for post surgical tendon evaluation
Knee Surgery Sports Traumatology Arthroscopy, 2018Co-Authors: Mathias Wulf, Mihir Shanker, Michael Schuetz, Michael Lutz, Christian M Langton, Sue L Hooper, James E Smeathers, Torsten Brauner, Scott C WearingAbstract:Purpose: This cross-sectional study used transmission-mode ultrasound to evaluate dynamic tendon properties during walking in surgically repaired and contralateral Achilles tendon (AT), with a median (range) post-operative period of 22 (4-58) months. It was hypothesised that the axial transmission speed of ultrasound (TSOU) during walking would be slower, indicating lower Material Stiffness in repaired compared with contralateral AT. Methods: Ten patients [median (range) age 47 (37-69) years; height 180 (170-189) cm; weight 93 (62-119) kg], who had undergone open surgical repair of the AT and were clinically recovered according to their treating clinicians, walked barefoot on a treadmill at self-selected speed (1.0 ± 0.2 m/s). Synchronous measures of TSOU, sagittal ankle motion, vertical ground reaction force (GRF), and spatiotemporal gait parameters were recorded during 20 s of steady-state walking. Paired t tests were used to evaluate potential between-limb differences in TSOU, GRF, ankle motion, and spatiotemporal gait parameters. Results: TSOU was significantly lower (≈175 m/s) in the repaired than in the contralateral AT over the entire gait cycle (P < 0.05). Sagittal ankle motion was significantly greater (≈3°) in the repaired than in the contralateral limb (P = 0.036). There were no significant differences in GRF or spatiotemporal parameters between limbs. Conclusions: Repaired AT was characterised by a lower TSOU, reflecting a lower Material Stiffness in the repaired tendon than in the contralateral tendon. A lower Material Stiffness may underpin greater ankle joint motion of the repaired limb during walking and long-term deficits in the muscle-tendon unit reported with AT repair. Treatment and rehabilitation approaches that focus on increasing the Material Stiffness of the repaired AT may be clinically beneficial. Transmission-mode ultrasound would seem useful for quantifying tendon properties post AT rupture repair and may have the potential to individually guide rehabilitation programmes, thereby aiding safer return to physical activity. Level of evidence: II.
-
Lower Material Stiffness in rupture-repaired Achilles tendon during walking: transmission-mode ultrasound for post-surgical tendon evaluation.
Knee surgery sports traumatology arthroscopy : official journal of the ESSKA, 2017Co-Authors: Mathias Wulf, Mihir Shanker, Michael Schuetz, Michael Lutz, Christian M Langton, Sue L Hooper, James E Smeathers, Torsten Brauner, Scott C WearingAbstract:Purpose This cross-sectional study used transmission-mode ultrasound to evaluate dynamic tendon properties during walking in surgically repaired and contralateral Achilles tendon (AT), with a median (range) post-operative period of 22 (4–58) months. It was hypothesised that the axial transmission speed of ultrasound (TSOU) during walking would be slower, indicating lower Material Stiffness in repaired compared with contralateral AT.
D Rittel - One of the best experts on this subject based on the ideXlab platform.
-
on stress strain shielding and the Material Stiffness paradigm for dental implants
Clinical Implant Dentistry and Related Research, 2017Co-Authors: R Korabi, K Shemtovyona, D RittelAbstract:Background Stress shielding considerations suggest that the dental implant Material's compliance should be matched to that of the host bone. However, this belief has not been confirmed from a general perspective, either clinically or numerically. Purpose To characterize the influence of the implant Stiffness on its functionality using the failure envelope concept that examines all possible combinations of mechanical load and application angle for selected stress, strain and displacement-based bone failure criteria. Those criteria represent bone yielding, remodeling, and implant primary stability, respectively Materials and methods We performed numerical simulations to generate failure envelopes for all possible loading configurations of dental implants, with Stiffness ranging from very low (polymer) to extremely high, through that of bone, titanium, and ceramics. Results Irrespective of the failure criterion, stiffer implants allow for improved implant functionality. The latter reduces with increasing compliance, while the trabecular bone experiences higher strains, albeit of an overall small level. Micromotions remain quite small irrespective of the implant's Stiffness. Conclusion The current paradigm favoring reduced implant Material's Stiffness out of concern for stress or strain shielding, or even excessive micromotions, is not supported by the present calculations, that point exactly to the opposite.
-
On stress/strain shielding and the Material Stiffness paradigm for dental implants.
Clinical implant dentistry and related research, 2017Co-Authors: R Korabi, K. Shemtov-yona, D RittelAbstract:Background Stress shielding considerations suggest that the dental implant Material's compliance should be matched to that of the host bone. However, this belief has not been confirmed from a general perspective, either clinically or numerically. Purpose To characterize the influence of the implant Stiffness on its functionality using the failure envelope concept that examines all possible combinations of mechanical load and application angle for selected stress, strain and displacement-based bone failure criteria. Those criteria represent bone yielding, remodeling, and implant primary stability, respectively Materials and methods We performed numerical simulations to generate failure envelopes for all possible loading configurations of dental implants, with Stiffness ranging from very low (polymer) to extremely high, through that of bone, titanium, and ceramics. Results Irrespective of the failure criterion, stiffer implants allow for improved implant functionality. The latter reduces with increasing compliance, while the trabecular bone experiences higher strains, albeit of an overall small level. Micromotions remain quite small irrespective of the implant's Stiffness. Conclusion The current paradigm favoring reduced implant Material's Stiffness out of concern for stress or strain shielding, or even excessive micromotions, is not supported by the present calculations, that point exactly to the opposite.
Holger Lange - One of the best experts on this subject based on the ideXlab platform.
-
Strain in InP/ZnSe, S core/shell quantum dots from lattice mismatch and shell thickness-Material Stiffness influence.
The Journal of chemical physics, 2019Co-Authors: Mona Rafipoor, Hans Tornatzky, Dorian Dupont, Janina Maultzsch, Mickael D Tessier, Zeger Hens, Holger LangeAbstract:We investigate the buildup of strain in InP quantum dots with the addition of shells of the lower-lattice constant Materials ZnSe and ZnS by Raman spectroscopy. Both Materials induce compressive strain in the core, which increases with increasing shell volume. We observe a difference in the shell behavior between the two Materials: the thickness-dependence points toward an influence of the Material Stiffness. ZnS has a larger Young's modulus and requires less Material to develop stress on the InP lattice at the interface, while ZnSe requires several layers to form a stress-inducing lattice at the interface. This hints at the Material Stiffness being an additional parameter of relevance for designing strained core/shell quantum dots.
-
strain in inp znse s core shell quantum dots from lattice mismatch and shell thickness Material Stiffness influence
Journal of Chemical Physics, 2019Co-Authors: Mona Rafipoor, Hans Tornatzky, Dorian Dupont, Janina Maultzsch, Mickael D Tessier, Zeger Hens, Holger LangeAbstract:We investigate the buildup of strain in InP quantum dots with the addition of shells of the lower-lattice constant Materials ZnSe and ZnS by Raman spectroscopy. Both Materials induce compressive strain in the core, which increases with increasing shell volume. We observe a difference in the shell behavior between the two Materials: the thickness-dependence points toward an influence of the Material Stiffness. ZnS has a larger Young's modulus and requires less Material to develop stress on the InP lattice at the interface, while ZnSe requires several layers to form a stress-inducing lattice at the interface. This hints at the Material Stiffness being an additional parameter of relevance for designing strained core/shell quantum dots.
Anton E. Bowden - One of the best experts on this subject based on the ideXlab platform.
-
the lumbar supraspinous ligament demonstrates increased Material Stiffness and strength on its ventral aspect
Journal of The Mechanical Behavior of Biomedical Materials, 2013Co-Authors: Daniel J. Robertson, R. Willardson, D. Parajuli, A. Cannon, Anton E. BowdenAbstract:The present work represents the first reported quantified anisotropic, inhomogeneous Material constitutive data for the human supraspinous ligament (SSL). Multi-axial Material data from 30 human cadaveric SSL samples was collected from distinct locations (dorsal, midsection, and ventral). A structurally motivated strain-energy based continuum model was employed to characterize anisotropic constitutive parameters for each sample. The anisotropic constitutive response correlated well with the reported experimental data (R2>0.97). Results show that in the lumbar spine both the Material Stiffness and stress at failure were significantly higher in the ventral region of the SSL as compared with the dorsal region (p<0.05). In the along fiber direction a higher Stiffness and stress at failure were observed when compared to the transverse direction. These results indicate that modeling spinal ligaments using the hyperelastic line elements that have typically been used may be insufficient to capture their complex Material response.
-
The lumbar supraspinous ligament demonstrates increased Material Stiffness and strength on its ventral aspect
Journal of the mechanical behavior of biomedical materials, 2012Co-Authors: Daniel J. Robertson, R. Willardson, D. Parajuli, A. Cannon, Anton E. BowdenAbstract:The present work represents the first reported quantified anisotropic, inhomogeneous Material constitutive data for the human supraspinous ligament (SSL). Multi-axial Material data from 30 human cadaveric SSL samples was collected from distinct locations (dorsal, midsection, and ventral). A structurally motivated strain-energy based continuum model was employed to characterize anisotropic constitutive parameters for each sample. The anisotropic constitutive response correlated well with the reported experimental data (R2>0.97). Results show that in the lumbar spine both the Material Stiffness and stress at failure were significantly higher in the ventral region of the SSL as compared with the dorsal region (p
R Korabi - One of the best experts on this subject based on the ideXlab platform.
-
on stress strain shielding and the Material Stiffness paradigm for dental implants
Clinical Implant Dentistry and Related Research, 2017Co-Authors: R Korabi, K Shemtovyona, D RittelAbstract:Background Stress shielding considerations suggest that the dental implant Material's compliance should be matched to that of the host bone. However, this belief has not been confirmed from a general perspective, either clinically or numerically. Purpose To characterize the influence of the implant Stiffness on its functionality using the failure envelope concept that examines all possible combinations of mechanical load and application angle for selected stress, strain and displacement-based bone failure criteria. Those criteria represent bone yielding, remodeling, and implant primary stability, respectively Materials and methods We performed numerical simulations to generate failure envelopes for all possible loading configurations of dental implants, with Stiffness ranging from very low (polymer) to extremely high, through that of bone, titanium, and ceramics. Results Irrespective of the failure criterion, stiffer implants allow for improved implant functionality. The latter reduces with increasing compliance, while the trabecular bone experiences higher strains, albeit of an overall small level. Micromotions remain quite small irrespective of the implant's Stiffness. Conclusion The current paradigm favoring reduced implant Material's Stiffness out of concern for stress or strain shielding, or even excessive micromotions, is not supported by the present calculations, that point exactly to the opposite.
-
On stress/strain shielding and the Material Stiffness paradigm for dental implants.
Clinical implant dentistry and related research, 2017Co-Authors: R Korabi, K. Shemtov-yona, D RittelAbstract:Background Stress shielding considerations suggest that the dental implant Material's compliance should be matched to that of the host bone. However, this belief has not been confirmed from a general perspective, either clinically or numerically. Purpose To characterize the influence of the implant Stiffness on its functionality using the failure envelope concept that examines all possible combinations of mechanical load and application angle for selected stress, strain and displacement-based bone failure criteria. Those criteria represent bone yielding, remodeling, and implant primary stability, respectively Materials and methods We performed numerical simulations to generate failure envelopes for all possible loading configurations of dental implants, with Stiffness ranging from very low (polymer) to extremely high, through that of bone, titanium, and ceramics. Results Irrespective of the failure criterion, stiffer implants allow for improved implant functionality. The latter reduces with increasing compliance, while the trabecular bone experiences higher strains, albeit of an overall small level. Micromotions remain quite small irrespective of the implant's Stiffness. Conclusion The current paradigm favoring reduced implant Material's Stiffness out of concern for stress or strain shielding, or even excessive micromotions, is not supported by the present calculations, that point exactly to the opposite.