162 research outputs found

    Unconventional Anomalous Hall Effect in the Metallic Triangular-Lattice Magnet PdCrO2

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    We experimentally reveal an unconventional anomalous Hall effect (UAHE) in a quasi-two-dimensional triangular-lattice antiferromagnet PdCrO2. Using high quality single crystals of PdCrO2, we found that the Hall resistivity deviates from the conventional behavior below T* = 20 K, noticeably lower than TN = 37.5 K, at which Cr^{3+} (S=3/2) spins order in a 120 degree structure. In view of the theoretical expectation that the spin chirality cancels out in the simplest 120 degree spin structure, we discuss required conditions for the emergence of UAHE within Berry-phase mechanisms.Comment: 4 pages, 5 figures, accepted for publication in PR

    Range Extension Control System for Electric Vehicles Based on Optimal-Deceleration Trajectory and Front-Rear Driving-Braking Force Distribution Considering Maximization of Energy Regeneration

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    Abstract-Electric vehicles (EVs) have become a world-widely recognized solution for future green transportation. However, the mileage per charge of EVs is short compared with that of internal combustion engine vehicles. In this paper, a maximization method of regenerative energy is proposed. The method optimizes the velocity trajectory and distribution ratio of front and rear braking force using calculus of variations. The effectiveness of the proposed method is verified by simulations and experiments

    Design-Based Comparative Advantage: An Explanatory Analysis (Japanese)

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    In this paper we attempt to integrate the open view of manufacturing on the basis of design into the theory of comparative advantage, one of the bases of the theory of industrial competitiveness. That is to say, we propose a "theory of design-based comparative advantage" from the standpoint that design location precedes production location: a view that arises from hands-on experience at plants or design facilities. We also seek out the mechanism that creates comparative advantage in design in the context of the design process at the shop floor at which a company is engaged in development, and through a simple simulation model we attempt to recreate the process through which comparative advantage in design manifests itself.

    A Study on Topology Optimization of Optical Circuits Consisting of Multi-Materials

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    A topology optimization method can be used to find out the optical waveguide structures which have the desired transmission characteristics. Using the function expansion method, we can avoid the problem of a gray area, which means that some areas having intermediate refractive index between those of usable materials appear in a design region. However, so far, topology optimization has mainly been studied for structures consisting of two isotropic materials. In this paper, we study the applicability of topology optimization to structures which include three or more materials, and demonstrate the optimal design of a waveguide crossing

    Inhibition of Phosphodiesterase-4 (PDE4) activity triggers luminal apoptosis and AKT dephosphorylation in a 3-D colonic-crypt model

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    BACKGROUND: We previously established a three-dimensional (3-D) colonic crypt model using HKe3 cells which are human colorectal cancer (CRC) HCT116 cells with a disruption in oncogenic KRAS, and revealed the crucial roles of oncogenic KRAS both in inhibition of apoptosis and in disruption of cell polarity; however, the molecular mechanism of KRAS-induced these 3-D specific biological changes remains to be elucidated. RESULTS: Among the genes that were upregulated by oncogenic KRAS in this model, we focused on the phosphodiesterase 4B (PDE4B) of which expression levels were found to be higher in clinical tumor samples from CRC patients in comparison to those from healthy control in the public datasets of gene expression analysis. PDE4B2 was specifically overexpressed among other PDE4 isoforms, and re-expression of oncogenic KRAS in HKe3 cells resulted in PDE4B overexpression. Furthermore, the inhibition of PDE4 catalytic activity using rolipram reverted the disorganization of HCT116 cells into the normal physiologic state of the epithelial cell polarity by inducing the apical assembly of ZO-1 (a tight junction marker) and E-cadherin (an adherens junction marker) and by increasing the activity of caspase-3 (an apoptosis marker) in luminal cavities. Notably, rolipram reduced the AKT phosphorylation, which is known to be associated with the disruption of luminal cavity formation and CRC development. Similar results were also obtained using PDE4B2-shRNAs. In addition, increased expression of PDE4B mRNA was found to be correlated with relapsed CRC in a public datasets of gene expression analysis. CONCLUSIONS: These results collectively suggested that PDE4B is upregulated by oncogenic KRAS, and also that the inhibition of PDE4 catalytic activity can induce both epithelial cell polarity and luminal apoptosis in CRC, thus highlighting the utility of our 3-D culture (3 DC) model for the KRAS-induced development of CRC in 3-D microenvironment. Indeed, using this model, we found that PDE4B is a promising candidate for a therapeutic target as well as prognostic molecular marker in CRC. Further elucidation of the signaling network of PDE4B2 in 3 DC would provide a better understanding of CRC in vivo

    Nuclear Accumulation of HSP70 in Mouse Skeletal Muscles in Response to Heat Stress, Aging, and Unloading With or Without Reloading

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    The purpose of this study was to investigate the nuclear accumulation of heat shock protein 70 (HSP70), a molecular chaperonin in mouse skeletal muscle in response to aging, heat stress, and hindlimb unloading with or without reloading. Profiles of HSP70-specific nuclear transporter Hikeshi in skeletal muscles were also evaluated. Heat stress-associated nuclear accumulation of HSP70 was observed in slow soleus (SOL) and fast plantaris (PLA) muscles of young (10-week-old) mice. Mean nuclear expression level of HSP70 in slow medial gastrocnemius (MGAS) and PLA muscles of aged (100-week-old) mice increased ~4.8 and ~1.7 times, compared to that of young (10-week-old) mice. Reloading following 2-week hindlimb unloading caused accumulation of HSP70 in myonuclei in MGAS and PLA of young mice ( p < 0.05). However, reloading-associated nuclear accumulation of HSP70 was not observed in both types of muscles of aged mice. On the other hand, 2-week hindlimb unloading had no impact on the nuclear accumulation of HSP70 in both muscles of young and aged mice. Nuclear expression level of Hikeshi in both MGAS and PLA in mice was suppressed by aging. No significant changes in the nuclear Hikeshi in both muscles were induced by unloading with or without reloading. Results of this study indicate that the nuclear accumulation of HSP70 might show a protective response against cellular stresses in skeletal muscle and that the protective response may be suppressed by aging. Protective response to aging might depend on muscle fiber types
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