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- Dussaux, A., et al.
(författare)
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Local dynamics of topological magnetic defects in the itinerant helimagnet FeGe.
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Chiral magnetic interactions induce complex spin textures including helical and conical spin spirals, as well as particle-like objects such as magnetic skyrmions and merons. These spin textures are the basis for innovative device paradigms and give rise to exotic topological phenomena, thus being of interest for both applied and fundamental sciences. Present key questions address the dynamics of the spin system and emergent topological defects. Here we analyse the micromagnetic dynamics in the helimagnetic phase of FeGe. By combining magnetic force microscopy, single-spin magnetometry and Landau-Lifschitz-Gilbert simulations we show that the nanoscale dynamics are governed by the depinning and subsequent motion of magnetic edge dislocations. The motion of these topologically stable objects triggers perturbations that can propagate over mesoscopic length scales. The observation of stochastic instabilities in the micromagnetic structure provides insight to the spatio-temporal dynamics of itinerant helimagnets and topological defects, and discloses open challenges regarding their technological usage.
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3. |
- Yamada, K., et al.
(författare)
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Targeted Therapy for Low Back Pain in Elderly Degenerative Lumbar Scoliosis
- 2016
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 0362-2436. ; 41:10, s. 872-879
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Prospective cohort study. Objective. To compare the novel treatment procedure with nonoperative treatment for low back pain (LBP) in elderly patients with degenerative lumbar scoliosis (DLS). Summary of Background Data. Treatment of LBP associated with elderly DLS is controversial. We developed a novel treatment procedure, termed percutaneous intervertebral-vacuum polymethylmethacrylate injection (PIPI). Methods. We included patients with de novo DLS aged >= 65 years who had LBP with a visual analogue scale (VAS) score of >50 for >= 6 months with intervertebral vacuum and vertebral bone marrow edema (BME) defined on fat-saturated T2-weighted or gadolinium-enhanced T1-weighted magnetic resonance imaging. The primary outcomes were evaluated using the VAS score and modified Oswestry Disability Index (ODI). As an objective measurement, we scored BME on magnetic resonance imaging. Results. Between August 2004 and July 2011, 109 patients underwent PIPI and 53 received nonoperative treatment. At 1 month, mean improvements in VAS scores were -55.3 (95% CI, -60.5 to -50.1) and -1.9 (CI, -7.7 to 3.8) and mean improvements in ODI were -22.7 (CI, -27.3 to -18.2) and -0.6 (CI, -6.6 to 5.4) for the PIPI and nonoperative groups, respectively. At 2 years, mean improvements in VAS scores were -52.2 (CI, -59.9 to -44.4) and -4.0 (CI, -10.9 to 3.0) and mean improvements in ODI were -20.7 (CI, -27.3 to -14.5) and -1.0 (CI, -7.7 to 5.7) for the PIPI and nonoperative groups, respectively. BME substantially decreased in the PIPI group compared with the nonoperative group (P < 0.001) and correlated with VAS score and ODI improvements (VAS score: r = 0.502, P < 0.001; ODI: r = 0.372, P< 0.001). Conclusion. PIPI improved treatment for LBP, with a sustained clinical benefit for at least 2 years.
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