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$_3$, well known to have anti-trimerization.Comment: 6 + 7 pages, 3 + 5 figures, 0 + 1 table; Journal reference adde

Multi-Player Virtual Ping-Pong Game

In this paper we show how a motion capture system and feedback mechanism can be integrated into a virtual ping-pong game to create a multi-player platform. To trace the motion of each player, optical markers are attached to dif-ferent places on each player’s paddle. For tactile feedback, we designed a controller for a DC (Direct Current) mo-tor, which is also attached to the paddle. This controller communicates with the game server through wireless Blue-tooth technology. When the game server detects a collision between the paddle and ball, the controller receives the message from the game server and then triggers one of the respective paddle’s DC motors to vibrate depending on the position of the impact on the paddle. During an exhibition many people positively responded to the game

Metronidazole-induced encephalopathy in a patient with liver cirrhosis

Encephalopathy is a disorder characterized by altered brain function, which can be attributed to various causes. Encephalopathy associated with metronidazole administration occurs rarely and depends on the cumulative metronidazole dose, and most patients with this condition recover rapidly after discontinuation of therapy. Because metronidazole is metabolized in the liver and can be transported by the cerebrospinal fluid and cross the blood-brain barrier, it may induce encephalopathy even at a low cumulative dose in patients with hepatic dysfunction. We experienced a patient who showed ataxic gait and dysarthric speech after receiving metronidazole for the treatment of hepatic encephalopathy that was not controlled by the administration of lactulose. The patient was diagnosed as metronidazole-induced encephalopathy, and stopping drug administration resulted in a complete recovery from encephalopathy. This case shows that caution should be exercised when administering metronidazole because even a low dose can induce encephalopathy in patients with liver cirrhosis

Development of Laser Ruler in Rigid Laryngoscope

ObjectivesThe objective of this study was to develop a new device that provides a simple, noninvasive method of measuring accurate lesion size while using an endoscope.MethodsWe developed a rigid laryngoscope with a built-in laser-ruler using a one-light emitting diode and an acrylic plate. The invention incorporates a built-in laser diode that projects an auto-parallel beam into the optical path of the rigid laryngoscope to form two spots in the field of view.ResultsWhile the interspot distance remains consistent despite changes in focal plane, magnification, or viewing angle of the laryngoscope, projection to an uneven surface introduces certain variations in the shape, and size of the spots, and the distance between the two spots.ConclusionThe device enables a laryngologist to easily measure the distance between landmarks, as well as the change in real size, and the progressive change of vocal fold lesions in an outpatient setting

SREBP1c-CRY1 signalling represses hepatic glucose production by promoting FOXO1 degradation during refeeding

SREBP1c is a key lipogenic transcription factor activated by insulin in the postprandial state. Although SREBP1c appears to be involved in suppression of hepatic gluconeogenesis, the molecular mechanism is not thoroughly understood. Here we show that CRY1 is activated by insulin-induced SREBP1c and decreases hepatic gluconeogenesis through FOXO1 degradation, at least, at specific circadian time points. SREBP1c−/− and CRY1−/− mice show higher blood glucose than wild-type (WT) mice in pyruvate tolerance tests, accompanied with enhanced expression of PEPCK and G6Pase genes. CRY1 promotes degradation of nuclear FOXO1 by promoting its binding to the ubiquitin E3 ligase MDM2. Although SREBP1c fails to upregulate CRY1 expression in db/db mice, overexpression of CRY1 attenuates hyperglycaemia through reduction of hepatic FOXO1 protein and gluconeogenic gene expression. These data suggest that insulin-activated SREBP1c downregulates gluconeogenesis through CRY1-mediated FOXO1 degradation and that dysregulation of hepatic SREBP1c-CRY1 signalling may contribute to hyperglycaemia in diabetic animals