6,364 research outputs found
Magnon topology and thermal Hall effect in trimerized triangular lattice antiferromagnet
The non-trivial magnon band topology and its consequent responses have been
extensively studied in two-dimensional magnetisms. However, the triangular
lattice antiferromagnet (TLAF), the best-known frustrated two-dimensional
magnet, has received less attention than the closely related Kagome system,
because of the spin-chirality cancellation in the umbrella ground state of the
undistorted TLAF. In this work, we study the band topology and the thermal Hall
effect (THE) of the TLAF with (anti-)trimerization distortion under the
external perpendicular magnetic field using the linearized spin wave theory. We
show that the spin-chirality cancellation is removed in such case, giving rise
to the non-trivial magnon band topology and the finite THE. Moreover, the
magnon bands exhibit band topology transitions tuned by the magnetic field. We
demonstrate that such transitions are accompanied by the logarithmic divergence
of the first derivative of the thermal Hall conductivity. Finally, we examine
the above consequences by calculating the THE in the hexagonal manganite
YMnO, well known to have anti-trimerization.Comment: 6 + 7 pages, 3 + 5 figures, 0 + 1 table; Journal reference adde
Ultra Compact Nanoporous Platinum Coating Improves Neural Recording
Neural electrodes are key tools for achieving a successful brain-computer interface and the electrodes should be small to minimize damage to neural tissue and obtain good spatial selectivity such as single unit recording. Here we show conventional platinum/tungsten neural probes can be coated with nanoporous Pt. Thanks to nanoporous Pt with the extremely small and uniform pores, L-2-ePt, the electrode impedance could be reduced by more than 2 orders of magnitude while the apparent area was almost the same. L-2-ePt coating enhanced neuronal recording of local field potential in monkeys, leading to facilitating implanted electrical devices in the nervous system.Peer reviewe
Improved Chest Anomaly Localization without Pixel-level Annotation via Image Translation Network Application in Pseudo-paired Registration Domain
Image translation based on a generative adversarial network (GAN-IT) is a
promising method for the precise localization of abnormal regions in chest
X-ray images (AL-CXR) even without pixel-level annotation. However,
heterogeneous unpaired datasets undermine existing methods to extract key
features and distinguish normal from abnormal cases, resulting in inaccurate
and unstable AL-CXR. To address this problem, we propose an improved two-stage
GAN-IT involving registration and data augmentation. For the first stage, we
introduce an advanced deep-learning-based registration technique that virtually
and reasonably converts unpaired data into paired data for learning
registration maps, by sequentially utilizing linear-based global and uniform
coordinate transformation and AI-based non-linear coordinate fine-tuning. This
approach enables the independent and complex coordinate transformation of each
detailed location of the lung while recognizing the entire lung structure,
thereby achieving higher registration performance with resolving inherent
artifacts caused by unpaired conditions. For the second stage, we apply data
augmentation to diversify anomaly locations by swapping the left and right lung
regions on the uniform registered frames, further improving the performance by
alleviating imbalance in data distribution showing left and right lung lesions.
The proposed method is model agnostic and shows consistent AL-CXR performance
improvement in representative AI models. Therefore, we believe GAN-IT for
AL-CXR can be clinically implemented by using our basis framework, even if
learning data are scarce or difficult for the pixel-level disease annotation
A Case of Vogt-Koyanagi-Harada Disease in a Patient With Graves Disease
A case of Vogt-Koyanagi-Harada disease (VKH) that developed in a 36-year-old woman with Graves' disease was described. The patient was treated with Lugol's solution and presented with bilateral serous retinal detachment. She had also suffered from methimazole-induced hypersensitivity and steroid-induced myopathy. Fluorescein angiography showed multiple leakage points and a lumbar puncture revealed pleocytosis, which was compatible with VKH. High dose steroid pulse therapy was successful. Altered immune regulation associated with drug-induced hypersensitivity may contribute to the development of VKH in patients with Graves' disease
Wireless sEMG System with a Microneedle-Based High-Density Electrode Array on a Flexible Substrate
Surface electromyography (sEMG) signals reflect muscle contraction and hence, can provide information regarding a user's movement intention. High-density sEMG systems have been proposed to measure muscle activity in small areas and to estimate complex motion using spatial patterns. However, conventional systems based on wet electrodes have several limitations. For example, the electrolyte enclosed in wet electrodes restricts spatial resolution, and these conventional bulky systems limit natural movements. In this paper, a microneedle-based high-density electrode array on a circuit integrated flexible substrate for sEMG is proposed. Microneedles allow for high spatial resolution without requiring conductive substances, and flexible substrates guarantee stable skin-electrode contact. Moreover, a compact signal processing system is integrated with the electrode array. Therefore, sEMG measurements are comfortable to the user and do not interfere with the movement. The system performance was demonstrated by testing its operation and estimating motion using a Gaussian mixture model-based, simplified 2D spatial pattern.111Ysciescopu
Early versus Late Intravitreal Triamcinolone Acetonide for Macular Edema associated with Branch Retinal Vein Occlusion
PURPOSE: To compare the effect of early versus late intravitreal injection of triamcinolone in patients with macular edema due to branch retinal vein occlusion (BRVO). METHODS: Twenty eyes of 20 patients with macular edema from BRVO, including 10 with duration after onset of or 3 months, improvements in visual acuity and foveal thickness, though apparent at 1 month, were not maintained at 3 and 6 months post-triamcinolone. CONCLUSIONS: Intravitreal triamcinolone is more effective in patients with BRVO who are treated earlier
- …