191 research outputs found

    Magnetic properties of the Ag-In-rare-earth 1/1 approximants

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    We have performed magnetic susceptibility and neutron scattering measurements on polycrystalline Ag-In-RE (RE: rare-earth) 1/1 approximants. In the magnetic susceptibility measurements, for most of the RE elements, inverse susceptibility shows linear behaviour in a wide temperature range, confirming well localized isotropic moments for the RE3+^{3+} ions. Exceptionally for the light RE elements, such as Ce and Pr, non-linear behaviour was observed, possibly due to significant crystalline field splitting or valence fluctuation. For RE = Tb, the susceptibility measurement clearly shows a bifurcation of the field-cooled and zero-field-cooled susceptibility at Tf=3.7T_{\rm f} = 3.7~K, suggesting a spin-glass-like freezing. On the other hand, neutron scattering measurements detect significant development of short-range antiferromagnetic spin correlations in elastic channel, which accompanied by a broad peak at ω=4\hbar\omega = 4~meV in inelastic scattering spectrum. These features have striking similarity to those in the Zn-Mg-Tb quasicrystals, suggesting that the short-range spin freezing behaviour is due to local high symmetry clusters commonly seen in both the systems.Comment: 14 pages, 12 figure

    Identification of the Tandem Running Pheromone in Diacamma sp. from Japan (Hymenoptera, Formicidae)

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    The Japanese queenless ponerine ant Diacamma sp. from Japan employs tandem running during nest relocation, in which a leader ant guides nestmate followers one at a time. We replicated this process by presenting one entire abdominal part of a leader, except for the petiole to followers. When the abdominal part had been rinsed with n-hexane, however, it attracted significantlyfewer followers. This suggests that chemicals on the leader’s abdominal part evoke tandem running. Dissection of abdominal major exocrine glands revealed that the Dufour’s gland was the source of this chemical signal. The chemicals were eluted in the hydrocarbon fraction by silica-gel column chromatography, and the quantitatively major component was estimated as heptadecene (C17:1) through gas chromatograph-mass spectrometer (GCMS) analysis. The position of the double bond was estimated to be between the 8th and 9th carbons through analysis of the epoxidized compound. Only (Z)-isomers of 8-heptadecene evoked tandem running in the followers. We identified the tandem running pheromone of this ant species to be (Z)-8- heptadecene. (163

    Direct growth of vertically aligned single-walled CNTs on conducting substrate and its electrochemical performance in ionic liquids

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    We report fabrication of vertically-aligned single-walled carbon nanotube (VA-SWCNT) electrodes for a symmetric electrochemical capacitor using a simple ethanol-based CNT growth system. From the CNT direct growth technique, the electrode was easily prepared, and consequently assembled with ionic liquid as electrolyte. VA-SWCNTs were directly grown on conducting SUS 310S foils in which the binder material was not incorporated in the capacitor structure. This capacitor demonstrated excellent gravimetric capacitance and a high rate capability. From the cyclic voltammetric analysis, the capacitance was contributed not only from the ideal double layer capacitance, but also from faradaic processes that might have occurred during charge-discharge. Other than the capacitance, the VA-SWCNT capacitor was also measured by using frequency response (impedance) and charge-discharge analyses

    Energy-Efficient Robot Configuration and Motion Planning Using Genetic Algorithm and Particle Swarm Optimization

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    The implementation of Industry 5.0 necessitates a decrease in the energy consumption of industrial robots. This research investigates energy optimization for optimal motion planning for a dual-arm industrial robot. The objective function for the energy minimization problem is stated based on the execution time and total energy consumption of the robot arm configurations in its workspace for pick-and-place operation. Firstly, the PID controller is being used to achieve the optimal parameters. The parameters of PID are then fine-tuned using metaheuristic algorithms such as Genetic Algorithms and Particle Swarm Optimization methods to create a more precise robot motion trajectory, resulting in an energy-efficient robot configuration. The results for different robot configurations were compared with both motion planning algorithms, which shows better compatibility in terms of both execution time and energy efficiency. The feasibility of the algorithms is demonstrated by conducting experiments on a dual-arm robot, named as duAro. In terms of energy efficiency, the results show that dual-arm motions can save more energy than single-arm motions for an industrial robot. Furthermore, combining the robot configuration problem with metaheuristic approaches saves energy consumption and robot execution time when compared to motion planning with PID controllers alone

    Effects of seed lots and seed production time on growth, flowering and cut flower quality in Bupleurum rotundifolium L.

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    Effects of seed lots (No. 021793, 025090, 026247, 027668) and seed production time on growth, flowering and cut flower quality in Bupleurum rotundifolium L. were investigated. The rate of germination was different depending on the seed lots, 021793 was lowest, and 026247 was highest. Days to visible bud and flowering were the shortest at 025090, and longest at 026247. The rate of germination of seed harvested on home seed-raising was different for seed production time. Seed harvested during high temperature period from the middle of June to the beginning of July showed remarkably high rate of germination. While plants grown by seed harvested during high temperature period remarkably delayed flowering and had low cut flower quality, plants grown on seed harvested during low temperature period enhanced flowering and had high cut flower quality. There was a little difference in parental line. It was thought that seed production time was affected by the environmental conditions during seed production time than by the seed lot

    Dealkylation of alkyl polycyclic aromatic hydrocarbon over silica monolayer solid acid catalyst

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    Dealkylation of alkylnaphthalene, as a model of alkyl polycyclic aromatic hydrocarbon compounds in heavy oils, proceeded selectively on a silica monolayer solid acid catalyst. The activity was generated by the deposition of silica on alumina with generation of Brønsted acidity. The activity and Brønsted acid amount showed the maximum where the monolayer covered the surface, indicating that the Brønsted acid site generated on the silica monolayer was the active species. The activity and selectivity on the silica monolayer were high compared to other aluminosilicate catalysts, and high activity was observed even after calcination at 973–1173K

    Combined treatment with dipeptidyl peptidase 4 (DPP4) inhibitor sitagliptin and elemental diets reduced indomethacin-induced intestinal injury in rats via the increase of mucosal glucagon-like peptide-2 concentration.

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    The gut incretin glucagon-like peptide-1 (GLP-1) and the intestinotropic hormone GLP-2 are released from enteroendocrine L cells in response to ingested nutrients. Treatment with an exogenous GLP-2 analogue increases intestinal villous mass and prevents intestinal injury. Since GLP-2 is rapidly degraded by dipeptidyl peptidase 4 (DPP4), DPP4 inhibition may be an effective treatment for intestinal ulcers. We measured mRNA expression and DPP enzymatic activity in intestinal segments. Mucosal DPP activity and GLP concentrations were measured after administration of the DPP4 inhibitor sitagliptin (STG). Small intestinal ulcers were induced by indomethacin (IM) injection. STG was given before IM treatment, or orally administered after IM treatment with or without an elemental diet (ED). DPP4 mRNA expression and enzymatic activity were high in the jejunum and ileum. STG dose-dependently suppressed ileal mucosal enzyme activity. Treatment with STG prior to IM reduced small intestinal ulcer scores. Combined treatment with STG and ED accelerated intestinal ulcer healing, accompanied by increased mucosal GLP-2 concentrations. The reduction of ulcers by ED and STG was reversed by co-administration of the GLP-2 receptor antagonist. DPP4 inhibition combined with luminal nutrients, which up-regulate mucosal concentrations of GLP-2, may be an effective therapy for the treatment of small intestinal ulcers

    Amino acid alterations in Gag that confer the ability to grow in simian cells on HIV-1 are located at a narrow CA region

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    We previously generated a prototype monkey-tropic human immunodeficiency virus type 1 (HIV-1) designated NL-DT5R. This viral clone has a small region of simian immunodeficiency virus (SIV) within Gag capsid (CA) protein and also SIV Vif protein, but displays a poor growth phenotype in simian cells. To improve the growth potential of NL-DT5R, we have constructed a series of its gag variant viruses. Out of fourteen viral clones generated, five were infectious for simian HSC-F cells, and two of the infectious variants grew similarly with NL-DT5R. Taking their genome structures into consideration, our data here clearly show that a narrow CA region within the Gag protein, i.e., the domain around cyclophilin A (CypA)-binding loop, is critical for the growth ability of HIV-1 in simian cells

    Real-Time PCR Assay for the Diagnosis and Quantification of Co-infections by Diaporthe batatas and Diaporthe destruens in Sweet Potato

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    Foot rot disease caused by Diaporthe destruens (formerly Plenodomus destruens) has become a major concern for the production of sweet potato [Ipomoea batatas (L.) Lam.] in Japan. A related fungus Diaporthe batatas, which causes dry rot disease of sweet potato, is native and is widespread in fields in Japan. The similar characteristics of these two pathogens pose a challenge for conventional disease diagnosis. Currently, there are no effective molecular measures for identifying and distinguishing D. destruens and D. batatas. Here, we demonstrate a real-time PCR assay that distinguishes and quantifies D. batatas and D. destruens from co-infected sweet potato. The assay was performed with various simulated DNA combinations of D. batatas and D. destruens ranging from 1:1 to 1:100000. The assay was also used with the ratios of D. batatas: D. destruens: sweet potato DNA ranging from 1:1:1 to 1:1:100000. These assays produced a specific amplification product for each of the pathogens, and quantified the fungal biomass over the entire range tested without detecting false positives. The assay was validated by using infected sweet potato collected from various fields; it showed sufficient sensitivity and specificity to quantify and distinguish D. batatas and D. destruens from these field samples. Thus, our real-time PCR assay would be a useful tool for diagnosis of D. batatas and D. destruens and is expected to provide the foundation for the design of integrated disease management strategies for foot rot disease in sweet potato
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