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Abstract The Berry curvature dipole (BCD) serves as a one of the fundamental contributors to emergence of the nonlinear Hall effect (NLHE). Despite intense interest due to its potential for new technologies reaching beyond the quantum efficiency limit, the interplay between BCD and NLHE has been barely understood yet in the absence of a systematic study on the electronic band structure. Here, we report NLHE realized in NbIrTe4 that persists above room temperature coupled with a sign change in the Hall conductivity at 150 K. First-principles calculations combined with angle-resolved photoemission spectroscopy (ARPES) measurements show that BCD tuned by the partial occupancy of spin-orbit split bands via temperature is responsible for the temperature-dependent NLHE. Our findings highlight the correlation between BCD and the electronic band structure, providing a viable route to create and engineer the non-trivial Hall effect by tuning the geometric properties of quasiparticles in transition-metal chalcogen compounds.

Abstract Interfacial magnetic interactions between different elements are the origin of various spin-transport phenomena in multi-elemental magnetic systems. We investigate the coupling between the magnetic moments of the rare-earth, transition-metal, and heavy-metal elements across the interface in a GdFeCo/Pt thin film, an archetype system to investigate ferrimagnetic spintronics. The Pt magnetic moments induced by the antiferromagnetically aligned FeCo and Gd moments are measured using element-resolved x-ray measurements. It is revealed that the proximity-induced Pt magnetic moments are always aligned parallel to the FeCo magnetic moments, even below the ferrimagnetic compensation temperature where FeCo has a smaller moment than Gd. This is understood by a theoretical model showing distinct effects of the rare-earth Gd 4f and transition-metal FeCo 3d magnetic moments on the Pt electronic states. In particular, the Gd and FeCo work in-phase to align the Pt moment in the same direction, despite their antiferromagnetic configuration. The unexpected additive roles of the two antiferromagnetically coupled elements exemplify the importance of detailed interactions among the constituent elements in understanding magnetic and spintronic properties of thin film systems.

Abstract We investigate the voltage control of magnetism in a van der Waals (vdW) heterostructure device consisting of two distinct vdW materials, the ferromagnetic Fe3-x GeTe2 and the ferroelectric In2Se3. It is observed that gate voltages applied to the Fe3-x GeTe2/In2Se3 heterostructure device modulate the magnetic properties of Fe3-x GeTe2 with significant decrease in coercive field for both positive and negative voltages. Raman spectroscopy on the heterostructure device shows voltage-dependent increase in the in-plane In2Se3 and Fe3-x GeTe2 lattice constants for both voltage polarities. Thus, the voltage-dependent decrease in the Fe3-x GeTe2 coercive field, regardless of the gate voltage polarity, can be attributed to the presence of in-plane tensile strain. This is supported by density functional theory calculations showing tensile-strain-induced reduction of the magnetocrystalline anisotropy, which in turn decreases the coercive field. Our results demonstrate an effective method to realize low-power voltage-controlled vdW spintronic devices utilizing the magnetoelectric effect in vdW ferromagnetic/ferroelectric heterostructures.

Abstract Background Alopecia refers to a condition developed by gradual reduction of hair loss by various abnormal causes such as endocrine system, genetic factors, and stress. Stromal vascular fraction (SVF) isolated from the fat is one of the latest innovative solutions in the field of regeneration therapy. We focused on presenting effectiveness of clinical cases to improve AGA through transplantation of autologous SVF into the scalp. Objective To confirm the efficacy of the autologous SVF usage to the patients with AGA. Methods Nine patients (age range 43–64 years; 4 men, grade IV to V and 5 women, grade I to III), who are suffering from androgenic alopecia (AGA), were treated with single transplantation of autologous SVF in the upper scalp. Autologous SVF was isolated and characterized prior to the injection of live 7–9 × 106 cells into the patients’ treatment site. The hair loss improvement effect was assessed by three test criteria: hair skin quality, hair thickness and hair density 3 and 6 months after post-injection compared to pre-injection status. Results Hair density of SVF-treated side was significantly increased after 3 and 6 months of transplantation compared to non-treated side (P = 0.01 and P = 0.009 per each). And significant improvement in the score of the keratin on the scalp was seen in the injected area as compared to the non-injected area 6 months after transplantation (P = 0.032). Although thickness increase was observed at 3 and 6 months after transplantation, there was no statistical significance (P = 0.142 and 0.155, respectively). Conclusions One transplantation of autologous SVF for the AGA patients, hair density and score for the keratin were significantly increased within 6 months. This study shows that SVF is a very effective way to treat hair loss and most of subjects are satisfied with the result after treatment.

Abstract Numerical generation of physical states is essential to all scientific research fields. The role of a numerical generator is not limited to understanding experimental results; it can also be employed to predict or investigate characteristics of uncharted systems. A variational autoencoder model is devised and applied to a magnetic system to generate energetically stable magnetic states with low local deformation. The spin structure stabilization is made possible by taking the explicit magnetic Hamiltonian into account to minimize energy in the training process. A significant advantage of the model is that the generator can create a long‐range ordered ground state of spin configuration by increasing the role of stabilization even if the ground states are not necessarily included in the training process. It is expected that the proposed Hamiltonian‐guided generative model can bring about great advances in numerical approaches used in various scientific research fields.

Spin torques with different origins enable the magnetic domain wall motion, but the contributions are hard to be distinguished. Here, the authors show the method to measure both spin-magnetization transfer torque and spin–orbit torque by using mountain-shaped domains with straight domain walls.

Non-zero topological charge prevents the straight motion of ferromagnetic skyrmions and hinders their applications. Here, the authors report the stabilization and current-driven dynamics of skyrmions in GdFeCo films in which the ferrimagnetic skyrmions can move with high velocity and reduced skyrmion Hall angle.

We observed a humplike feature in Hall effects of SrRuO_{3} ultrathin films, and systematically investigated it by controlling thicknesses, temperatures and magnetic fields. The humplike feature is extremely stable, even surviving as a magnetic field is tilted by as much as 85^{∘}. Based on the atomic-level structural analysis of a SrRuO_{3} ultrathin film with a theoretical calculation, we reveal that atomic rumplings at the thin-film surface enhance Dzyaloshinskii-Moriya interaction, which can generate stable chiral spin textures and a humplike Hall effect. Moreover, temperature dependent resonant x-ray measurements at the Ru L edge under a magnetic field showed that the intensity modulation of unexpected peaks was correlated with the hump region in the Hall effect. We verify that the two-dimensional property of ultrathin films generates stable noncoplanar spin textures having a magnetic order in a ferromagnetic oxide material.

Magnetic skyrmions are potentially suitable for future spintronic devices, but their dynamical behaviour in real space remains elusive. Here, Wooet al. report nanosecond-dynamics of a 100nm-size magnetic skyrmion triggered by current-induced spin-orbit torques.

The interfacial perpendicular magnetic anisotropy in W/CoFeB (1.2 ∼ 3 nm)/MgO thin film structures is strongly dependent on temperature, and is significantly reduced at high temperature. The interfacial magnetic anisotropy is generally proportional to the third power of magnetization, but an additional factor due to thermal expansion is required to explain the temperature dependence of the magnetic anisotropy of ultrathin CoFeB films. The reduction of the magnetic anisotropy is more prominent for the thinner films; as the temperature increases from 300 K to 400 K, the anisotropy is reduced ∼50% for the 1.2-nm-thick CoFeB, whereas the anisotropy is reduced ∼30% for the 1.7-nm-thick CoFeB. Such a substantial reduction of magnetic anisotropy at high temperature is problematic for data retention when incorporating W/CoFeB/MgO thin film structures into magneto-resistive random access memory devices. Alternative magnetic materials and structures are required to maintain large magnetic anisotropy at elevated temperatures.

Video compression exploits statistical, spatial, and temporal redundancy, as well as transform and quantization. In particular, the transform in a frequency domain plays a major role in energy compaction of spatial domain data into frequency domain data. The high efficient video coding standard uses the type‐II discrete cosine transform (DCT‐II) and type‐VII discrete sine transform (DST‐VII) to improve the coding efficiency of residual data. However, the DST‐VII is applied only to the Intra 4 × 4 residual block because it yields relatively small gains in the larger block than in the 4 × 4 block. In this study, after rearranging the data of the residual block, we apply the DST‐VII to the inter‐residual block to achieve coding gain. The rearrangement of the residual block data is similar to the arrangement of the basis vector with a the lowest frequency component of the DST‐VII. Experimental results show that the proposed method reduces the luma‐chroma (Cb+Cr) BD rates by approximately 0.23% to 0.22%, 0.44% to 0.58%, and 0.46% to 0.65% for the random access, low delay B, and low delay P configurations, respectively.

Despite the international trend of actively utilizing BIM in the field of energy simulation, it is difficult to actively utilize BIM in domestic certification-related practice. As a result, the work process is not integrated and the work efficiency is reduced, such as the occurrence of redundant tasks. In this paper, the integrated process based on the BIM geometry information automated extraction module was presented and its effectiveness was reviewed and verified through self-developed automation module and uniformity and error-causing analysis. The construction of an integrated process through automatic configuration information extraction has the advantages of reducing the workload, enabling additional tasks through module function expansion, sharing information through the web, and ease of service manufacture. In addition, an experiment comparing the data of automatic and manual calculations with three subjects confirmed that automatic calculation database through automation module can produce a more reliable and uniform database with a lower proportion of human error than the manual calculation module. This not only improves the reliability of the energy simulation itself, but also reduces the human and temporal loads that occur during the post-simulation data verification process.

The structure, magnetic and ferroelectric properties of sputtered epitaxial CoFe2O4-BiFeO3 (CFO-BFO) nanocomposite thin films grown on La0.7Sr0.3MnO3 (LSMO) layers on (001) oriented SrTiO3 (STO) substrates and on STO-buffered Si are described. The as-grown LSMO thin films were smooth and poorly conductive but the resistivity was reduced and the surfaces roughened after annealing. Cosputtered CFO and BFO on STO formed vertically aligned nanostructures consisting of epitaxial spinel CFO pillars within a perovskite BFO matrix, but the rough surface of the annealed LSMO film promoted additional CFO pillar orientations. A reorientation of the CFO magnetic easy axis to an in-plane direction occurred as the LSMO became thicker due to changes in the strain state of the CFO pillars. The LSMO underlayer enabled the ferroelectric response of the BFO to be measured. Nanocomposites were grown onto LSMO/SrTiO3/Si which provides a path towards large scale integration of electrically contacted nanocomposites on Si. [ABSTRACT FROM AUTHOR]

In this study, the development of a deep learning approach for distinguishing cardiomegaly in chest X-ray images and its validation process are presented. Typically, radiologists diagnose cardiomegaly by examining X-ray images. However, their interpretations can vary owing to subjective judgments, and mild cardiomegaly can be missed. For this reason, there is ongoing research into the use of AI-based deep learning algorithms as an adjunct to X-ray interpretation. In this study, radiologists collected 10,000 public images, from which 718 useful images were selected to create a dataset. A DenseNet121 algorithm was then used to develop an AI model for cardiomegaly detection. The results demonstrate an accuracy of 0.95, a recall of 0.91, and an F1 score of 0.94. Additional validation was performed to ensure the accuracy of the cardiomegaly detection model. The validation methods included saliency maps and guided backpropagation, which indicated the significance of the model. In conclusion, this study demonstrates the potential to develop a high-quality AI model with fewer data than previous studies, suggesting its applicability in the medical field.

Electric-field-induced modification of magnetic anisotropy is studied using tunnel magnetoresistance of the Co40Fe40B20/ MgO/ Co40Fe40B20 and Co40Fe40B20/ Hf (0.08 nm)/ MgO/ Co40Fe40B20 magnetic tunnel junctions. In both systems, the interfacial perpendicular magnetic anisotropy is increased with increasing electron density at the MgO interface. A quantitative comparison between the two systems reveals that the change of magnetic anisotropy energy with electric field is significantly enhanced in Co40Fe40B20/ Hf/ MgO/ Co40Fe40B20 compared to Co40Fe40B20/ MgO/ Co40Fe40B20. The sub-monolayer Hf insertion at the Co40Fe40B20/MgO interface turns out to be critical to the enhanced electric field control of the magnetic anisotropy, indicating the interface sensitive nature of the effect. [ABSTRACT FROM AUTHOR]

Sleep apnea has emerged as a significant health issue in modern society, with self-diagnosis and effective management becoming increasingly important. Among the most renowned methods for self-diagnosis, the STOP-BANG questionnaire is widely recognized as a simple yet effective tool for diagnosing and assessing the risk of sleep apnea. However, its sensitivity and specificity have limitations, necessitating the need for tools with higher performance. Consequently, this study aimed to enhance the accuracy of sleep apnea diagnoses by integrating machine learning with the STOP-BANG questionnaire. Research through actual cases was conducted based on the data of 262 patients undergoing polysomnography, confirming sleep apnea with a STOP-BANG score of ≥3 and an Apnea–Hypopnea Index (AHI) of ≥5. The accuracy, sensitivity, and specificity were derived by comparing Apnea–Hypopnea Index scores with STOP-BANG scores. When applying machine learning models, four hyperparameter-tuned models were utilized: K-Nearest Neighbor (K-NN), Logistic Regression, Random Forest, and Support Vector Machine (SVM). Among them, the K-NN model with a K value of 11 demonstrated superior performance, achieving a sensitivity of 0.94, specificity of 0.85, and overall accuracy of 0.92. These results highlight the potential of combining traditional STOP-BANG diagnostic tools with machine learning technology, offering new directions for future research in self-diagnosis and the preliminary diagnosis of sleep-related disorders in clinical settings.