A key to room-temperature ferromagnetism in Fe-doped ZnO: Cu

Successful synthesis of room-temperature ferromagnetic semiconductors, Zn$_{1-x}$Fe$_{x}$O, is reported. The essential ingredient in achieving room-temperature ferromagnetism in bulk Zn$_{1-x}$Fe$_{x}$O was found to be additional Cu doping. A transition temperature as high as 550 K was obtained in Zn$_{0.94}$Fe$_{0.05}$Cu$_{0.01}$O; the saturation magnetization at room temperature reached a value of $0.75 \mu_{\rm B}$ per Fe. Large magnetoresistance was also observed below $100$K.Comment: 11 pages, 4 figures; to appear in Appl. Phys. Let

Dynamic behaviors in directed networks

Motivated by the abundance of directed synaptic couplings in a real biological neuronal network, we investigate the synchronization behavior of the Hodgkin-Huxley model in a directed network. We start from the standard model of the Watts-Strogatz undirected network and then change undirected edges to directed arcs with a given probability, still preserving the connectivity of the network. A generalized clustering coefficient for directed networks is defined and used to investigate the interplay between the synchronization behavior and underlying structural properties of directed networks. We observe that the directedness of complex networks plays an important role in emerging dynamical behaviors, which is also confirmed by a numerical study of the sociological game theoretic voter model on directed networks

Warm needle acupuncture for osteoarthritis: A systematic review and meta-analysis.

Warm needle acupuncture (WA) is considered a potential intervention in the treatment of osteoarthritis (OA). To systematically evaluate the clinical efficacy and safety of WA in the treatment of OA. Systematic review and meta-analysis METHODS: Fourteen databases were searched from their inception until May 2022. Randomized controlled trials (RCTs) of WA for treating OA were identified. Study selection and data extraction were performed by two independent reviewers. The Cochrane risk of bias tool and the Grading of Recommendations Assessment, Development and Evaluation program were used to assess all included RCTs. A total of 66 RCTs met the inclusion criteria for this review. Most of the included studies had an unclear risk of bias, and the certainty of the evidence was very low. Twenty-four RCTs compared the effects of WA with those of oral drug therapies. Meta-analysis showed superior effects of WA for the total effective rate (risk ratio (RR): 1.22, 95% confidence interval (CI): 1.17 to 1.27, I  = 26%, p < 0.001, 24 studies, n = 2278), pain, and function. Eight RCTs compared the effects of WA+drug therapy, and meta-analysis showed favorable effects for the total effective rate (RR: 1.27, 95% CI: 1.18 to 1.35, I =0%, p < 0.001, 8 studies, n = 646). Eight RCTs compared the effects of WA and intra-articular sodium hyaluronate (IASH) injection on OA and found equivalent effects of WA on the symptoms of OA. Twenty-eight RCTs compared the effects of WA+IASH injection with those of IASH injection, and meta-analysis showed superior effects of WA+IASH in terms of the total effective rate (RR: 1.15, 95% CI: 1.11 to 1.19, I =27.3%, p < 0.001, 25 studies, n = 2208), pain, and function. None of the RCTs reported serious adverse events. WA may have some distinct advantages in the treatment of OA. However, well-designed RCTs with larger sample sizes are needed. [Abstract copyright: Copyright © 2022 The Author(s). Published by Elsevier GmbH.. All rights reserved.

Near-Horizon Conformal Symmetry and Black Hole Entropy in Any Dimension

Recently, Carlip proposed a derivation of the entropy of the two-dimensional dilatonic black hole by investigating the Virasoro algebra associated with a newly introduced near-horizon conformal symmetry. We point out not only that the algebra of these conformal transformations is not well defined on the horizon, but also that the correct use of the eigenvalue of the operator $L_0$ yields vanishing entropy. It has been shown that these problems can be resolved by choosing a different basis of the conformal transformations which is regular even at the horizon. We also show the generalization of Carlip's derivation to any higher dimensional case in pure Einstein gravity. The entropy obtained is proportional to the area of the event horizon, but it also depends linearly on the product of the surface gravity and the parameter length of a horizon segment in consideration. We finally point out that this derivation of black hole entropy is quite different from the ones proposed so far, and several features of this method and some open issues are also discussed.Comment: 14 pages, no figur