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Chaohui Ye - One of the best experts on this subject based on the ideXlab platform.
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Spin-Locking Mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
Solid State Nuclear Magnetic Resonance, 2000Co-Authors: Yan Zhang, Feng Deng, Chaohui YeAbstract:The spin-Locking Mechanism of the spin I = 3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrodinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-Locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-Locking signals. The spin-Locking for a spin I = 3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences. (C) 2000 Elsevier Science B.V. All rights reserved.
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Spin-Locking Mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
Solid State Nuclear Magnetic Resonance, 2000Co-Authors: Yan Zhang, Feng Deng, Chaohui YeAbstract:Abstract The spin-Locking Mechanism of the spin I=3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrodinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-Locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-Locking signals. The spin-Locking for a spin I=3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences.
Yan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Spin-Locking Mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
Solid State Nuclear Magnetic Resonance, 2000Co-Authors: Yan Zhang, Feng Deng, Chaohui YeAbstract:The spin-Locking Mechanism of the spin I = 3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrodinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-Locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-Locking signals. The spin-Locking for a spin I = 3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences. (C) 2000 Elsevier Science B.V. All rights reserved.
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Spin-Locking Mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
Solid State Nuclear Magnetic Resonance, 2000Co-Authors: Yan Zhang, Feng Deng, Chaohui YeAbstract:Abstract The spin-Locking Mechanism of the spin I=3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrodinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-Locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-Locking signals. The spin-Locking for a spin I=3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences.
Feng Deng - One of the best experts on this subject based on the ideXlab platform.
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Spin-Locking Mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
Solid State Nuclear Magnetic Resonance, 2000Co-Authors: Yan Zhang, Feng Deng, Chaohui YeAbstract:The spin-Locking Mechanism of the spin I = 3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrodinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-Locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-Locking signals. The spin-Locking for a spin I = 3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences. (C) 2000 Elsevier Science B.V. All rights reserved.
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Spin-Locking Mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
Solid State Nuclear Magnetic Resonance, 2000Co-Authors: Yan Zhang, Feng Deng, Chaohui YeAbstract:Abstract The spin-Locking Mechanism of the spin I=3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrodinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-Locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-Locking signals. The spin-Locking for a spin I=3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences.
Edward M. Vasarhelyi - One of the best experts on this subject based on the ideXlab platform.
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CURRENT TOTAL KNEE DESIGNS: EFFECT OF BASEPLATE ROUGHNESS AND Locking Mechanism ON POLYETHYLENE BACKSIDE WEAR
2018Co-Authors: Z. Sisko, Matthew G. Teeter, B. Lanting, James L. Howard, Richard W. Mccalden, Douglas D.r. Naudie, Steven J. Macdonald, Edward M. VasarhelyiAbstract:Previous retrieval studies demonstrate increased tibial baseplate roughness leads to higher polyethylene backside wear in total knee arthroplasty (TKA). Micromotion between the polyethylene backside and tibial baseplate is affected by the Locking Mechanism design and can further increase backside wear. The purpose of this study was to examine modern Locking Mechanisms, in the setting of both roughened and polished tibial baseplates, on backside tibial polyethylene wear.Five TKA models were selected, all with different tibial baseplate and/or Locking Mechanism designs. Six retrieval tibial polyethylenes from each TKA model were matched based on time in vivo (TIV), age at TKA revision, BMI, gender, number of times revised, and revision reason. Two observers scored each polyethylene backside according to a visual damage score and individual damage modes. Primary outcomes were mean damage score and individual damage modes. Demographics were compared by one-way ANOVA. Damage scores and modes were analysed by t...
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CURRENT TOTAL KNEE DESIGNS: EFFECT OF BASEPLATE ROUGHNESS AND Locking Mechanism ON POLYETHYLENE BACKSIDE WEAR
Journal of Bone and Joint Surgery-british Volume, 2016Co-Authors: Z. Sisko, Matthew G. Teeter, B. Lanting, James L. Howard, Richard W. Mccalden, Douglas D.r. Naudie, Steven J. Macdonald, Edward M. VasarhelyiAbstract:Previous retrieval studies demonstrate increased tibial baseplate roughness leads to higher polyethylene backside wear in total knee arthroplasty (TKA). Micromotion between the polyethylene backside and tibial baseplate is affected by the Locking Mechanism design and can further increase backside wear. The purpose of this study was to examine modern Locking Mechanisms, in the setting of both roughened and polished tibial baseplates, on backside tibial polyethylene wear. Five TKA models were selected, all with different tibial baseplate and/or Locking Mechanism designs. Six retrieval tibial polyethylenes from each TKA model were matched based on time in vivo (TIV), age at TKA revision, BMI, gender, number of times revised, and revision reason. Two observers scored each polyethylene backside according to a visual damage score and individual damage modes. Primary outcomes were mean damage score and individual damage modes. Demographics were compared by one-way ANOVA. Damage scores and modes were analysed by the Kruskal-Wallis test and Dunn9s multiple comparisons test. There were no differences among the groups based on TIV (p=0.962), age (p=0.651), BMI (p=0.951), gender, revision number, or reason for revision. There was a significant difference across groups for mean total damage score (p=0.029). The polished tibial design with a partial peripheral capture Locking Mechanism and anterior constraint demonstrated a significantly lower score compared to one of the roughened tibial designs with a complete peripheral-rim Locking Mechanism (13.0 vs. 22.1, p=0.018). Otherwise, mean total damage scores were not significant between groups. As far as modes of wear, there were identifiable differences among the groups based on abrasions (p=0.005). The polished design with a tongue-in-groove Locking Mechanism demonstrated a significantly higher score compared to both groups with roughened tibial baseplates (5.83 vs. 0.83, p=0.024 and 5.83 vs. 0.92, p=0.033). Only the two designs with roughened tibial baseplates demonstrated dimpling (5.67 and 8.67) which was significant when compared against all other groups (p0.99). No other significant differences were identified when examining burnishing, cold flow, scratching, or pitting. No polyethylene components exhibited embedded debris or delamination. Total damage scores were similar between all groups except when comparing one of the polished TKA design to one of the roughened designs. The other TKA model with a roughened tibial baseplate had similar damage scores to the polished designs, likely due to its updated Locking Mechanism. Dimpling wear patterns were specific for roughened tibial baseplates while abrasive wear patterns were identified in the design with a tongue-in-groove Locking Mechanism. Our study showed even in the setting of a roughened tibial baseplate, modern Locking Mechanisms decrease backside wear similar to that of other current generation TKA designs.
Alastair M. M. Richardson - One of the best experts on this subject based on the ideXlab platform.
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The digital tendon Locking Mechanism of owls: variation in the structure and arrangement of the Mechanism and functional implications
Emu - Austral Ornithology, 2007Co-Authors: Luke D. Einoder, Alastair M. M. RichardsonAbstract:This study provides evidence of morphological differences in support of the current phylogenetic division of the owls into two familes (Strigidae, Tytonidae), with respect to the digital tendon Locking Mechanism (TLM). This Mechanism consists of modified surfaces on the flexor tendons in the digits, which, when engaged form a lock that holds the digits in a flexed position. Although species-specific differences in TLM structure were apparent, consistent inter-family differences occurred in the degree of expression of the TLM, its location within the digit, and in the structure and arrangement of the Locking elements. Phylogenetic differences also occurred in the location of the associated digital ligaments. The TLM of the Strigidae was found to resemble that of the Falconiformes (Falconidae and Accipitridae). However, the Tytonidae possess a more distinctive pattern, characterised by a digit 1 TLM located at the opposite end of the digit and bearing reversed plicae. The biomechanics of the Mechanism are considered, along with the functional implications of the varying structures in an attempt to understand the adaptiveness, or otherwise, of this-little known structure within an avian order.
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An ecomorphological study of the raptorial digital tendon Locking Mechanism
Ibis, 2006Co-Authors: Luke D. Einoder, Alastair M. M. RichardsonAbstract:Extensive adaptive radiation in hindlimb design among raptors is well known. However, the degree of variation in the structure and expression of the digital tendon Locking Mechanism (TLM) and its adaptive significance have received little attention. This comparative morphological study of 12 raptor and three non-raptor species revealed a distinct raptorial design, characterized by a distally located TLM that is densely packed with Locking elements of increased robustness and height. Although the Falconiformes and Strigiformes converged upon this pattern, unique design features were identified among the nocturnal birds of prey. Variation in TLM structure was often consistent with phylogeny, although interfamily similarities were revealed among a number of species with the same dietary habit. The evolutionary factors that may have led to the observed variation, as well as the biomechanical implications of varying designs, are discussed.
