| 1. |
- Sheean, AJ, et al.
(författare)
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Quadriceps tendon autograft for arthroscopic knee ligament reconstruction: use it now, use it often
- 2018
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Ingår i: British journal of sports medicine. - : BMJ. - 1473-0480 .- 0306-3674. ; 52:11, s. 698-701
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Tidskriftsartikel (refereegranskat)abstract
- Traditional bone-patellar tendon-bone and hamstring tendon ACL grafts are not without limitations. A growing body of anatomic, biomechanical and clinical data has demonstrated the utility of quadriceps tendon autograft in arthroscopic knee ligament reconstruction. The quadriceps tendon autograft provides a robust volume of tissue that can be reliably harvested, mitigating the likelihood of variably sized grafts and obviating the necessity of allograft augmentation. Modern, minimally invasive harvest techniques offer the advantages of low rates of donor site morbidity and residual extensor mechanism strength deficits. New data suggest that quadriceps tendon autograft may possess superior biomechanical characteristics when compared with bone-patella tendon-bone (BPTB) autograft. However, there have been very few direct, prospective comparisons between the clinical outcomes associated with quadriceps tendon autograft and other autograft options (eg, hamstring tendon and bone-patellar tendon-bone). Nevertheless, quadriceps tendon autograft should be one of the primary options in any knee surgeon’s armamentarium.
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| 2. |
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| 3. |
- Pramanik, Prativa, et al.
(författare)
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Interplay of lattice-spin-orbital coupling and Jahn-Teller effect in noncollinear spinel Ti x Mn1-x (Fe y Co1-y )2O4 : a neutron diffraction study
- 2024
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Ingår i: Journal of Physics. - : Institute of Physics (IOP). - 0953-8984 .- 1361-648X. ; 36:35
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Tidskriftsartikel (refereegranskat)abstract
- Local magnetostructural changes and dynamical spin fluctuations in doubly diluted spinel TixMn1-x(FeyCo1-y)(2)O-4 has been reported by means of neutron diffraction and magnetization studies. Two distinct sets of compositions (i) x(Ti) = 0.20 and y(Fe) = 0.18; (ii) x(Ti) = 0.40 and y(Fe) = 0.435 have been considered for this study. The first compound of equivalent stoichiometry Ti0.20Mn0.80Fe0.36Co1.64O4 exhibits enhanced tetragonal distortion across the ferrimagnetic transition temperature T-C = 258 K in comparison to the end compound MnCo2O4 (T-C similar to 180 K) with a characteristic ratio c(t)/root 2a(t) of 0.99795(8) demonstrating robust lattice-spin-orbital coupling. However, in the second case Ti0.40Mn0.60Fe0.87Co1.13O4 with higher B-site compositions, the presence of Jahn-Teller ions with distinct behavior appears to counterbalance the strong tetragonal distortion thereby ceasing the lattice-spin-orbital coupling. Both the investigated systems show the coexistence of noncollinear antiferromagnetic and ferrimagnetic components in cubic and tetragonal settings. On the other hand, the dynamical ac-susceptibility, chi(ac)(T) reveals a cluster spin-glass state with Gabay-Toulouse (GT) like mixed phases behaviour below T-C. Such dispersive behaviour appears to be sensitive to the level of octahedral substitution. Further, the field dependence of chi(ac)(T) follows the weak anisotropic GT-line behaviour with crossover exponent Phi lies in the range 1.38-1.52 on the H-T plane which is in contrast to the B-site Ti substituted MnCo2O4 spinel that appears to follow irreversible non-mean-field AT-line behaviour (Phi similar to 3 + delta). Finally, the Arrott plots analysis indicates the presence of a pseudo first-order like transition (T < 20 K) which is in consonance with and zero crossover of the magnetic entropy change within the frozen spin-glass regime.
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| 4. |
- Pramanik, P., et al.
(författare)
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Neutron diffraction evidence for local spin canting, weak Jahn-Teller distortion, and magnetic compensation in Ti1-xMnxCo2O4 spinel
- 2020
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Ingår i: Journal of Physics. - : IOP PUBLISHING LTD. - 0953-8984 .- 1361-648X. ; 32:24
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Tidskriftsartikel (refereegranskat)abstract
- A systematic study using neutron diffraction and magnetic susceptibility is reported on Mn substituted ferrimagnetic inverse spinel Ti1-xMnxCo2O4 in the temperature interval 1.6 K T 300 K. Our neutron diffraction study reveals cooperative distortions of the TO6 octahedra in the Ti1-xMnxCo2O4 system for all the Jahn-Teller active ions T = Mn3+ , Ti3+ and Co3+ , having the electronic configurations 3d(1), 3d(4) and 3d(6), respectively which are confirmed by the x-ray photoelectron spectroscopy. Two specific compositions (x = 0.2 and 0.4) have been chosen in this study because these two systems show unique features such as; (i) noncollinear Yafet-Kittel type magnetic ordering, and (ii) weak tetragonal distortion with c/a < 1, in which the apical bond length d(c)(T-B-O) is longer than the equatorial bond length d(ab)(T-B-O) due to the splitting of the e(g) level of Mn3+ ions into and . For the composition x = 0.4, the distortion in the TBO6 octahedra is stronger as compared to x = 0.2 because of the higher content of trivalent Mn. Ferrimagnetic ordering in Ti0.6Mn0.4Co2O4 and Ti0.8Mn0.2Co2O4 sets in at 110.3 and 78.2 K, respectively due to the presence of unequal magnetic moments of cations, where Ti3+ , Mn3+ , and Co3+ occupy the octahedral, whereas, Co2+ sits in the tetrahedral site. For both compounds an additional weak antiferromagnetic component could be observed lying perpendicular to the ferrimagnetic component. The analysis of static and dynamic magnetic susceptibilities combined with the heat-capacity data reveals a magnetic compensation phenomenon (MCP) at T-COMP = 25.4 K in Ti0.8Mn0.2Co2O4 and a reentrant spin-glass behaviour in Ti0.6Mn0.4Co2O4 with a freezing temperature of 110.1 K. The MCP in this compound is characterized by sign reversal of magnetization and bipolar exchange bias effect below T-COMP with its magnitude depending on the direction of external magnetic field and the cooling protocol.
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