Valley-Selective Phonon-Magnon Scattering in Magnetoelastic Superlattices.

Phonons and magnons are engineered by periodic potential landscapes in phononic and magnonic crystals, and their combined studies may enable valley phonon transport tunable by the magnetic field. Through nonreciprocal surface acoustic wave transmission, we demonstrate valley-selective phonon-magnon scattering in magnetoelastic superlattices. The lattice symmetry and the out-of-plane magnetization component control the sign of nonreciprocity. The phonons in the valleys play a crucial role in generating nonreciprocal transmission by inducing circularly polarized strains that couple with the magnons. The transmission spectra show a nonreciprocity peak near a transmission gap, matching the phononic band structure. Our results open the way for manipulating valley phonon transport through periodically varying magnon-phonon coupling.

Quality assessment of conventional and traditional oriental medicine clinical practice guidelines for knee osteoarthritis using AGREE II instrument.

INTRODUCTION: Knee osteoarthritis is a degenerative disease and its prevalence tends to increase. Clinical practice guidelines (CPGs) are evidence-based recommendations for treatment that help policymakers, practitioners, and patients make more appropriate and efficient decisions during the course of management. This study aimed to evaluate the quality of knee osteoarthritis CPGs using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. METHOD: The retrieval engines and websites were utilized from January 2010 to December 2020. The search words were "Clinical practice guideline" OR "Critical practice guideline" OR "guideline∗" AND "Osteoarthritis." The quality of the CPGs was independently examined by four appraisers using the AGREE II instrument. Consequently, the selected CPGs were graded as Classes A, B, and C according to the level of recommendation. RESULT: In this study, 13 CPGs for knee osteoarthritis were selected and evaluated qualitatively using the AGREE II instrument. The overall quality percentage score was as follows: clarity of presentation, 72.6%, scope and purpose, 62.6%, rigor of development, 54.2%, stakeholder investment, 50.5%, editorial independence, 46.5%, applicability, 22.5%. CONCLUSION: Auxiliary materials for the treatment process of knee OA should be supplemented in future revised versions for quality improvement of knee OA CPGs. Also, more evidence should be accumulated to support the recommendation of traditional oriental medical treatments in the clinical field. From the perspective of integrative medicine, along with conventional pharmacological treatment, exercise, weight loss, and acupuncture can be combined together in clinical situations.

Traditional Korean Medicine as Collaborating Treatments with Conventional Treatments for Knee Osteoarthritis: A Protocol for a Systematic Review and Meta-Analysis.

BACKGROUND: Knee osteoarthritis (OA) is a degenerative disease of the joint cartilage with no definite treatment in the early stage. Several previous review studies have shown that alternative medical treatments, including acupuncture, moxibustion, and herbal medicines, are effective in improving the symptoms of the disease and the patient's quality of life. However, no systematic review study has shown the effectiveness of the combination of conventional and alternative therapies. Therefore, the aim of our study is to determine the most effective combination therapies and to provide evidence for the effectiveness and safety of integrated therapies. This article describes the protocol for the methods that will be applied in our systematic review. METHODS: We will conduct an electronic search of nine databases: PubMed, Embase, Cochrane, Google Scholar (first 100 articles), four Korean databases (KoreaMed, Korean Studies Information Service System, Research Information Service System, and Oriental Medicine Advanced Searching Integrated System), and one Chinese database (China National Knowledge Infrastructure). Only randomized controlled studies that reported on both conventional treatment (drugs and hyaluronic acid) and traditional Korean medicine (acupuncture, moxibustion, and herbal medicines) will be selected. The primary outcomes will be pain and function of the joint. The secondary outcomes will include pain relief duration, total effective rate, incidence of adverse events, and quality of life. We will assess the methodological quality of the included studies using the Cochrane risk of bias tool. For the meta-analysis, standardized mean differences and risk ratios with 95% confidence intervals will be applied for continuous and dichotomous data, respectively. RESULTS: This review will evaluate the effectiveness and safety of several Korean medicine treatments combined with conventional treatments for knee OA. CONCLUSION: Our review will provide a good foundation for the integrative treatment of knee OA.

Spin Hall Magnetoresistance in Metallic Bilayers.

Spin Hall magnetoresistance (SMR) is studied in metallic bilayers that consist of a heavy metal (HM) layer and a ferromagnetic metal (FM) layer. We find a nearly tenfold increase of SMR in W/CoFeB compared to previously studied HM/ferromagnetic insulator systems. The SMR increases with decreasing temperature despite the negligible change in the W layer resistivity. A model is developed to account for the absorption of the longitudinal spin current to the FM layer, one of the key characteristics of a metallic ferromagnet. We find that the model not only quantitatively describes the HM layer thickness dependence of SMR, allowing accurate estimation of the spin Hall angle and the spin diffusion length of the HM layer, but also can account for the temperature dependence of SMR by assuming a temperature dependent spin polarization of the FM layer. These results illustrate the unique role a metallic ferromagnetic layer plays in defining spin transmission across the HM/FM interface.

Interface control of the magnetic chirality in CoFeB/MgO heterostructures with heavy-metal underlayers.

Recent advances in the understanding of spin orbital effects in ultrathin magnetic heterostructures have opened new paradigms to control magnetic moments electrically. The Dzyaloshinskii-Moriya interaction (DMI) is said to play a key role in forming a Néel-type domain wall that can be driven by the spin Hall torque. Here we show that the strength and sign of the DMI can be changed by modifying the adjacent heavy-metal underlayer (X) in perpendicularly magnetized X/CoFeB/MgO heterostructures. The sense of rotation of a domain wall spiral is reversed when the underlayer is changed from Hf, Ta to W and the strength of DMI varies as the filling of 5d orbitals, or the electronegativity, of the heavy-metal layer changes. The DMI can even be tuned by adding nitrogen to the underlayer, thus allowing interface engineering of the magnetic texture in ultrathin magnetic heterostructures.

Layer thickness dependence of the current-induced effective field vector in Ta|CoFeB|MgO.

Current-induced effective magnetic fields can provide efficient ways of electrically manipulating the magnetization of ultrathin magnetic heterostructures. Two effects, known as the Rashba spin orbit field and the spin Hall spin torque, have been reported to be responsible for the generation of the effective field. However, a quantitative understanding of the effective field, including its direction with respect to the current flow, is lacking. Here we describe vector measurements of the current-induced effective field in Ta|CoFeB|MgO heterostructrures. The effective field exhibits a significant dependence on the Ta and CoFeB layer thicknesses. In particular, a 1 nm thickness variation of the Ta layer can change the magnitude of the effective field by nearly two orders of magnitude. Moreover, its sign changes when the Ta layer thickness is reduced, indicating that there are two competing effects contributing to it. Our results illustrate that the presence of atomically thin metals can profoundly change the landscape for controlling magnetic moments in magnetic heterostructures electrically.

Recent advances in the design of electro-optic sensors for minimally destructive microwave field probing.

In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE) of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms of optical alignment, spatial resolution, and especially, a low degree of field invasiveness. We propose and review five distinct types of fiber-coupled electro-optic sensor probes. The design guidelines for each probe type and their performances in absolute electric-field measurements are compared and summarized.

Effect of repetitive transcranial magnetic stimulation in a patient with chronic crossed aphasia: fMRI study.

OBJECTIVE: We report here the case of a 52-year-old Korean woman who was initially diagnosed with non-fluent/global crossed aphasia. METHODS AND RESULTS: Initial computed tomography of the brain revealed a haematoma of approximately 40 ml in the right basal ganglia area and cavitation around the right lateral ventricle. Three years after onset the aphasia was resolved to a conduction aphasia and she had an ongoing left-sided gait disturbance. Follow-up anatomical magnetic resonance imaging found no recurrence of haemorrhage. Language functional magnetic resonance imaging was examined before and after repetitive transcranial magnetic stimulation treatment. A 90-mm round coil stimulator was used and the repetitive transcranial magnetic stimulation treatment location was P3 on the 10-20 International electrode placement system (1 Hz, 20 min per day for 10 days over a 2-week period). Functional magnetic resonance imaging results before repetitive transcranial magnetic stimulation treatment showed no significant activity in either the ipsilesional or contralesional hemispheres for noun generation and sentence completion paradigms (p < 0.001, cluster size 128). Compared with the pre-treatment phase, following repetitive transcranial magnetic stimulation treatment the data from functional magnetic resonance imaging revealed significant activations in the right inferior frontal lobe (Broca's area), posterior temporal gyrus (Wernicke's area), and parietal lobe for both the noun generation and sentence completion tasks (p < 0.001, cluster size 128). CONCLUSION: This functional magnetic resonance imaging case study is the first to suggest the use of repetitive transcranial magnetic stimulation for improving language outcome in a patient with crossed aphasia. In addition, we report the value of language functional magnetic resonance imaging before and after repetitive transcranial magnetic stimulation treatment for determining the effect of treatment and the underlying neurobiological mechanism of functional recovery following repetitive transcranial magnetic stimulation treatment.