64 research outputs found

    Examination of High-Torque Sandwich-Type Spherical Ultrasonic Motor Using with High-Power Multimode Annular Vibrating Stator

    Get PDF
    Spherical ultrasonic motors (SUSMs) that can operate with multiple degrees of freedom (MDOF) using only a single stator have high holding torque and high torque at low speed, which makes reduction gearing unnecessary. The simple structure of MDOF-SUSMs makes them useful as compact actuators, but their development is still insufficient for applications such as joints of humanoid robots and other systems that require MDOF and high torque. To increase the torque of a sandwich-type MDOF-SUSM, we have not only made the vibrating stator and spherical rotor larger but also improved the structure using three design concepts: (1) increasing the strength of all three vibration modes using multilayered piezoelectric actuators (MPAs) embedded in the stator, (2) enhancing the rigidity of the friction driving portion of the stator for transmitting more vibration force to the friction-driven rotor surface, and (3) making the support mechanism more stable. An MDOF-SUSM prototype was tested, and the maximum torques of rotation around the X(Y)-axis and Z-axis were measured as 1.48 N?m and 2.05 N?m, respectively. Moreover, the values for torque per unit weight of the stator were obtained as 0.87 N?m/kg for the X(Y)-axis and 1.20 N?m/kg for the Z-axis. These are larger than values reported for any other sandwich-type MDOF-SUSM of which we are aware. Hence, the new design concepts were shown to be effective for increasing torque. In addition, we measured the transient response and calculated the load characteristics of rotation around the rotor’s three orthogonal axes

    Development of electromagnetic and piezoelectric hybrid actuator system

    Get PDF
    An ordinal force-feedback device typically uses an electromagnetic motor (EMM), which provides an excellent expression of elasticity. However, it is not easy to express the sense of hardness and roughness because the response of the current is delayed due to the inductance of the armature winding. On the contrary, a piezoelectric actuator, which has a rapid response, is good at expressing the sense of hardness and roughness. Thus, if different types of actuators are used in the same actuator system (AS), the weaknesses of each type can be compensated for. In this study, as an ideal force-feedback device, a hybrid actuator system combining an EMM with an ultrasonic motor (USM) and a piezoelectric clutch/brake (piezo-clutch/brake) is proposed and examined. This AS can expand the range of representable feelings. This paper describes the construction of a hybrid AS and some experimental results of a force-feedback display. In this experiment, the feelings of roughness, friction, and elasticity were represented. The feeling of roughness was represented by the on-off control of the piezo-brake at defined positions. The feeling of friction was represented by the PID control of braking using the piezo-clutch. The feeling of elasticity was represented by two methods: the use of the EMM and brake and the use of a combination of the USM, clutch, and brake. As a result, the hardness feeling was realistically represented by the piezo-brake, and the elastic feeling was represented by either the EMM or the USM

    A receptor-like kinase mutant with absent endodermal diffusion barrier displays selective nutrient homeostasis defects

    Get PDF
    We thank the Genomic Technologies Facility (GTF) and the Central Imaging Facility (CIF) of the University of Lausanne for expert technical support. We thank Valérie Dénervaud Tendon, Guillaume Germion, Deborah Mühlemann, and Kayo Konishi for technical assistance and John Danku and Véronique Vacchina for ICP-MS analysis. This work was funded by grants from the Swiss National Science Foundation (SNSF), the European Research Council (ERC) to NG and a Human Frontiers Science Program (HFSP) grant to JT and NG. GL and CM were supported by the Agropolis foundation (Rhizopolis) and the Agence Nationale de la Recherche (HydroRoot; ANR-11-BSV6-018). MB was supported by a EMBO long-term postdoctoral fellowship, JEMV by a Marie Curie IEF fellowship and TK by the Japan Society for the Promotion of Sciences (JSPS).Peer reviewedPublisher PD

    Establishment of an in planta magnesium monitoring system using CAX3 promoter-luciferase in Arabidopsis

    Get PDF
    The direct determination of elemental concentrations in plants is laborious. To overcome this, a novel monitoring system for magnesium (Mg) in plants was established. Mg deficiency-induced genes were identified by microarray analysis and transgenic lines that expressed luciferase (LUC) under the control of the Mg deficiency-inducible CAX3 promoter were established. The transgenic lines showed a clear response under low Mg conditions, and the degree of luminescence reflected the accumulation of endogenous CAX3 mRNA. The CAX3 expression pattern was also examined in a previously characterized low Mg-sensitive mutant, mrs2-7. In mrs2-7 mutant plants, CAX3 expression was more than three times higher than in the wild-type. In addition, CAX3 expression was negatively correlated with the shoot Mg concentration. Together, these results indicate that CAX3 transcription is a quantitative marker of the Mg status in Arabidopsis

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

    Get PDF
    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

    Get PDF
    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Direct in-situ temperature measurement for lamp-based heating device

    No full text
    Despite a wide variety of its practical applications, handiness, and cost-effectiveness, the advance of lamp-based heating devices is obstructed by one technical difficulty in measuring the temperature on a heated material. This difficulty originates in the combination of a polychromatic light source and a radiation thermometer that determines temperature from radiation (i.e. light). A new system developed in this study overcomes this intrinsic difficulty by measuring exclusively the radiation from the heated material, allowing us to perform the direct and in-situ measurement of temperature in a light-based heating device (an arc image furnace). Test measurements demonstrated the reliability of temperature measurement using the developed system as well as its promising potential for the determination of emissivity at high temperature particularly in the infrared region
    corecore