Showing papers by "Hiroshi Yamaguchi published in 2023"
TL;DR: In this article , the authors present a numerical analysis of the normal field instability for an initially flat layer of ferrofluid under the influence of magnetic field and a coupling between the simplified lattice Boltzmann method and the self-correcting procedure is developed to capture the velocity field and magnetic field.
1 citations
TL;DR: In this article , a case of Dravet syndrome caused by a 21-bp deletion in the intron of SCN1A was confirmed by minigene analysis, which has important implications for understanding HSES pathogenesis.
Abstract: Hemorrhagic shock and encephalopathy syndrome (HSES) is a serious condition that requires intensive care and is associated with a high mortality rate. However, its pathogenesis remains unclear. In the present study, a genetic analysis was performed to determine the genetic background of patients with clinically suspected Dravet syndrome (DS) who developed HSES.Whole exome sequencing was performed, followed by minigene analysis of the intron variant detected by whole exome sequencing to confirm its effect on splicing.Whole exome sequencing revealed a novel 21-bp deletion in intron 3 of SCN1A NM_001165963.4 (NC_000002.11:g.166073675_166073695del). This deletion was not found in the patient's parents and was proven to be de novo. Minigene analysis revealed an aberrant mRNA lacking 40 and 106 bp from the 5' end of exon 4 of SCN1A. Therefore, we diagnosed this case as DS due to the deletion in intron 3 of SCN1A.We report a case of DS with HSES caused by a 21-bp deletion in the intron of SCN1A that was confirmed by minigene analysis. The present case met Levin's criteria for HSES and the splicing analysis of SCN1A is an important finding. This study has important implications for understanding HSES pathogenesis.
TL;DR: In this paper , the behavior of human insulin hexamer in the absence of zinc was characterized using cryo-electron microscopy, and it was observed that these hexamers represented a structure similar to that of T6 insulin.
Abstract: Deeper understanding of the mechanism of the action of insulin and insulin-degrading enzyme (IDE) is a central theme in research into physiology and the pathophysiology of type 2 diabetes mellitus. Despite significant progress regarding the substrate recruitment, unfolding, digestion, and release by IDE, the structure and function of the insulin hexamer during the degradation cycle of IDE remain to be fully characterized. In the present study, we have characterized the behavior of human insulin hexamer in the absence of zinc. Using cryo-electron microscopy, we also observed that these hexamers represented a structure similar to that of T6 insulin. More interestingly, we also observed complexes in which some of their monomeric insulin components are partially distorted at their hexametric symmetry. This ensures that insulin determines the kinetics of its degradation by IDE without the requirement for zinc. These findings provide new information regarding the molecular events in insulin assembly and disassembly that permit its selective digestion by IDE.
TL;DR: In this article , the role of the hypothalamic A11 region and the medullary raphe nuclei in the regulation of defecation reflex was investigated using the double virus vector infection method in rats.
Abstract: The supraspinal brain regions controlling defecation reflex remain to be elucidated. The purpose of this study was to determine the roles of the hypothalamic A11 region and the medullary raphe nuclei in regulation of defecation. For chemogenetic manipulation of specific neurons, we used the double virus vector infection method in rats. hM3Dq or hM4Di was expressed in neurons of the A11 region and/or the raphe nuclei that send output to the lumbosacral defecation center. Immunohistological and functional experiments revealed that both the A11 region and the raphe nuclei directly connected with the lumbosacral spinal cord through descending pathways composed of stimulatory monoaminergic neurons. Stimulation of the hM3Dq-expressing neurons in the A11 region or the raphe nuclei enhanced colorectal motility only when GABAergic transmission in the lumbosacral spinal cord was blocked by bicuculline. Experiments using inhibitory hM4Di-expressing rats revealed that enhancement of colorectal motility caused by noxious stimuli in the colon is mediated by both the A11 region and the raphe nuclei. Furthermore, suppression of the A11 region and/or the raphe nuclei significantly inhibited water avoidance stress-induced defecation. These findings demonstrate that the A11 region and the raphe nuclei play an essential role in regulation of colorectal motility. This is important because brain regions that mediate both intracolonic noxious stimuli-induced defecation and stress-induced defecation have been clarified for the first time.
TL;DR: In this paper , the authors present a lightweight switchless network architecture by exploiting an indirect path, consisting of up to k one-hop paths for a diameter-k network topology, integrating interconnection network and memory channels into a lightweight memory-to-memory inter-FPGA network.
TL;DR: In this article , the authors demonstrate charge detection with single-electron resolution at high readout frequency using a silicon field effect transistor (FET) integrated with double resonant circuits.
Abstract: We demonstrate charge detection with single-electron resolution at high readout frequency using a silicon field-effect transistor (FET) integrated with double resonant circuits. A FET, whose channel of 10-nm width enables a single electron to be detected at room temperature, is connected to resonant circuits composed of coupled inductors and capacitors, and these double resonant circuits provide two resonance frequencies. When the FET is driven by a carrier signal at the lower resonance frequency, a small signal applied to the FET's gate modulates the resonance condition, resulting in a reflected signal appearing near the higher resonance frequency. Such operation utilizing the double resonant circuits enables charge detection with a single-electron resolution of 3 × 10−3 e/Hz0.5 and a readout frequency of 200 MHz at room temperature. In addition, a variable capacitor used in the double resonant circuits allows charge-sensing characteristics to be controlled in situ.
TL;DR: In this article , the authors focused on the duration of impaired consciousness and the detailed distribution of blood test values of children with complex febrile seizures during the acute phase, and provided important information for appropriate acute management of CFS.
Abstract: Abstract Background Patients with complex febrile seizures (CFS) often display abnormal laboratory results, unexpectedly prolonged seizures, and/or altered consciousness after admission. However, no standardized values have been established for the clinical and laboratory characteristics of CFS in the acute phase, making the management of CFS challenging. This study aimed to determine the clinical and laboratory characteristics of children with CFS during the acute phase. In particular, the duration of impaired consciousness and the detailed distribution of blood test values were focused. Methods We retrospectively reviewed medical records of a consecutive pediatric cohort aged 6–60 months who were diagnosed with CFS and admitted to Kobe Children’s Hospital between October 2002 and March 2017. During the study period, 486 seizure episodes with confirmed CFS were initially reviewed, with 317 seizure episodes included in the analysis. Detailed clinical and laboratory characteristics were summarized. Results Among 317 seizure episodes (296 children with CFS), 302 required two or fewer anticonvulsants to be terminated. In 296 episodes showing convulsive seizures, median seizure duration was 30.5 min. The median time from onset to consciousness recovery was 175 min. Impaired consciousness lasting > 6, 8, and 12 h was observed in 13.9%, 7.6%, and 1.9% patients with CFS, respectively. Additionally, the distribution of aspartate aminotransferase, lactate dehydrogenase, creatinine, and glucose were clarified with 3, 10, 50, 90, and 97 percentile values. Conclusion This study detailed the clinical and laboratory findings of acute-phase CFS using the data of the largest 15-year consecutive cohort of children with CFS. These results provide important information for appropriate acute management of CFS.
TL;DR: In this article , a patient on hemodialysis with severe coronavirus disease 2019 (COVID-19) was weaned from extracorporeal membrane oxygenation, which was used to treat severe COVID-2019 pneumonia.
Abstract: During the treatment of a patient on hemodialysis with severe coronavirus disease 2019 (COVID-19), the patient was weaned from extracorporeal membrane oxygenation, which was used to treat severe COVID-19 pneumonia. However, the patient’s condition worsened after the peak infection phase of COVID-19 because of acute respiratory distress syndrome with suspected hemophagocytic lymphohistiocytosis (HLH). After a bone marrow biopsy confirmed the diagnosis, methylprednisolone pulse therapy, followed by combination therapy (including oral prednisolone and cyclosporine) was immediately administered, and the patient survived. Because HLH can occur a month or more after the onset of COVID-19, even if the viral load is reduced to the point of being undetectable by reverse transcriptase-polymerase chain reaction, it can be considered to correspond to the “post-acute COVID-19 syndrome,” which has recently been proposed. Early intervention is necessary, because HLH can be fatal. Therefore, it is important to know that HLH can occur at any stage of COVID-19 and to pay attention to the patient’s progress over time, including checking the HScore.
TL;DR: In this paper , the authors explored the time course of serum cytokine level changes within 72 h after onset in acute encephalopathy (AE) and febrile seizures (FS).
Abstract: Abstract Background Cytokine levels have been measured in acute encephalopathy (AE) to determine its pathology or as a diagnostic biomarker to distinguish it from febrile seizures (FS); however, the dynamics of cytokine level changes have not yet been fully captured in these two neurological manifestations. Thus, we aimed to explore the time course of serum cytokine level changes within 72 h after onset in AE and FS. Methods We retrospectively measured cytokine level in residual serum samples at multiple timepoints in seven children whose final diagnoses were AE or FS. Results The levels of 13 cytokines appeared to increase immediately after onset and peaked within 12–24 h after onset: interleukin (IL)-1β, IL-4 IL-5, IL-6, IL-8, IL-10, IL-17, eotaxin, fibroblast growth factor, granulocyte colony-stimulating factor, interferon gamma, interferon-inducible protein-10, and macrophage chemoattractant protein-1. There were no dynamic changes in the levels of three cytokines (IL-1 receptor agonist, macrophage inflammatory protein-1α, and platelet-derived growth factor-bb) 72 h after onset. Levels of some cytokines decreased to around control levels within 48 h after onset: IL-1β, IL-4, IL-5, IL-17, fibroblast growth factor, and interferon gamma. The levels of most cytokines appeared to be higher in AE, especially in hemorrhagic shock encephalopathy syndrome, than in FS. Conclusions Cytokine levels in both AE and FS change dynamically, such as the levels of several cytokines increased within a few hours after onset and decreased at 12–24 h after onset. Therefore, it will be desirable to make clinical decisions regarding the administration of anti-inflammatory therapy in 24 h after onset in AE.
TL;DR: In this article , a high-sensitivity transistor with a multilayer graphene NEMS and double resonant circuits at an electrical resonance was used to detect high-frequency NEMS signals at subgigahertz or higher frequencies.
Abstract: A high-frequency nanoelectromechanical system (NEMS) based on a graphene membrane is a candidate for sensing applications, as well as a platform for fundamental research, but detecting such high-frequency oscillations of small membrane displacement is technically challenging. The authors integrate a high-sensitivity transistor with a multilayer graphene NEMS and drive the transistor via double resonant circuits at an electrical resonance. By optimizing the resonant circuits and driving the transistor with an rf signal, the high-frequency NEMS signal can be detected. This technique is useful for realizing NEMS applications at subgigahertz or higher frequencies.
01 Feb 2023
TL;DR: In this paper , acoustic induced dressed states of long-lived erbium ions in a crystal are demonstrated, formed by non-adiabatic modulation of two-level systems via strain induced by surface acoustic waves whose frequencies exceed the optical linewidth of the ion ensemble.
Abstract: Acoustically induced dressed states of long-lived erbium ions in a crystal are demonstrated. These states are formed by non-adiabatic modulation of two-level systems via strain induced by surface acoustic waves whose frequencies exceed the optical linewidth of the ion ensemble. Multiple sidebands and coherent destruction of tunneling appearing near the surface are evidence of a strong interaction between the acoustic waves and the ions. This development allows for on-chip control of long-lived ions and paves the way to highly coherent hybrid quantum systems with telecom photons, acoustic phonons, and electrons.
11 Apr 2023
TL;DR: In this article , the authors proposed to use quadrature variables, where their parametric coupling enables skyrmions to be stabilized, and a finite-element simulation indicates that a stable acoustic skyrmmion would exist in a realistic structure consisting of a piezoelectric membrane array.
Abstract: Skyrmions are topological solitons in two-dimensional systems and have been observed in various physical systems. Generating and controlling skyrmions in artificial resonator arrays lead to novel acoustic, photonic, and electric devices, but it is a challenge to implement a vector variable with the chiral exchange interaction. Here, we propose to use quadrature variables, where their parametric coupling enables skyrmions to be stabilized. A finite-element simulation indicates that a stable acoustic skyrmion would exist in a realistic structure consisting of a piezoelectric membrane array.