326 research outputs found

    Metal complex oligomer and polymer wires on electrodes: Tactical constructions and versatile functionalities

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    AbstractThis review covers recent progress in the construction of metal complex wires on various substrates via the stepwise coordination method, their functions, and the electrochemical evaluation of bis(terpyridine)metal complex oligomer wires on electrodes. In the layer-by-layer process of metal complex wire construction, various combinations of anchor ligands, metal sources, and bridging ligands have been used. The prepared structures show multiple functions, including photocurrent generation, catalytic activity, insulation properties, and long-range electron transport abilities. The electron transport behavior, and the long-range electron transport abilities from the terminal redox site to the electrode via bis(terpyridine)metal complex wires, were evaluated using potential step chronoamperometry. The remarkable long-range electron transport abilities were evidenced in the small values for the attenuation factor, β. The influence of the building blocks in the metal complex wires on the β value and the electron transfer rate constant was demonstrated

    Electric Wheelchair Hybrid Operating System Coordinated with Working Range of a Robotic Arm

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    Electric wheelchair-mounted robotic arms can help patients with disabilities to perform their activities in daily living (ADL). Joysticks or keypads are commonly used as the operating interface of Wheelchair-mounted robotic arms. Under different scenarios, some patients with upper limb disabilities such as finger contracture cannot operate such interfaces smoothly. Recently, manual interfaces for different symptoms to operate the wheelchair-mounted robotic arms are being developed. However, the stop the wheelchairs in an appropriate position for the robotic arm grasping task is still not easy. To reduce the individual’s burden in operating wheelchair in narrow spaces and to ensure that the chair always stops within the working range of a robotic arm, we propose here an operating system for an electric wheelchair that can automatically drive itself to within the working range of a robotic arm by capturing the position of an AR marker via a chair-mounted camera. Meanwhile, the system includes an error correction model to correct the wheelchair’s moving error. Finally, we demonstrate the effectiveness of the proposed system by running the wheelchair and simulating the robotic arm through several courses

    Sexual Experience Induces the Expression of Gastrin-Releasing Peptide and Oxytocin Receptors in the Spinal Ejaculation Generator in Rats

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    Male sexual function in mammals is controlled by the brain neural circuits and the spinal cord centers located in the lamina X of the lumbar spinal cord (L3-L4). Recently, we reported that hypothalamic oxytocin neurons project to the lumbar spinal cord to activate the neurons located in the dorsal lamina X of the lumbar spinal cord (dXL) via oxytocin receptors, thereby facilitating male sexual activity. Sexual experiences can influence male sexual activity in rats. However, how this experience affects the brain-spinal cord neural circuits underlying male sexual activity remains unknown. Focusing on dXL neurons that are innervated by hypothalamic oxytocinergic neurons controlling male sexual function, we examined whether sexual experience affects such neural circuits. We found that >50% of dXL neurons were activated in the first ejaculation group and similar to 30% in the control and intromission groups in sexually naive males. In contrast, in sexually experienced males, similar to 50% of dXL neurons were activated in both the intromission and ejaculation groups, compared to similar to 30% in the control group. Furthermore, sexual experience induced expressions of gastrin-releasing peptide and oxytocin receptors in the lumbar spinal cord. This is the first demonstration of the effects of sexual experience on molecular expressions in the neural circuits controlling male sexual activity in the spinal cord

    Geometric trade-off between contractile force and viscous drag determines the actomyosin-based motility of a cell-sized droplet

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    動きまわる人工細胞、その鍵は摩擦にあり --細胞が狭い空間を利用して運動する仕組みを解明--. 京都大学プレスリリース. 2022-07-21.Cell migration in confined environments is fundamental for diverse biological processes from cancer invasion to leukocyte trafficking. The cell body is propelled by the contractile force of actomyosin networks transmitted from the cell membrane to the external substrates. However, physical determinants of actomyosin-based migration capacity in confined environments are not fully understood. Here, we develop an in vitro migratory cell model, where cytoplasmic actomyosin networks are encapsulated into droplets surrounded by a lipid monolayer membrane. We find that the droplet can move when the actomyosin networks are bound to the membrane, in which the physical interaction between the contracting actomyosin networks and the membrane generates a propulsive force. The droplet moves faster when it has a larger contact area with the substrates, while narrower confinement reduces the migration speed. By combining experimental observations and active gel theory, we propose a mechanism where the balance between sliding friction force, which is a reaction force of the contractile force, and viscous drag determines the migration speed, providing a physical basis of actomyosin-based motility in confined environments

    Targeted disruption of hir1 alters the transcriptional expression pattern of putative lignocellulolytic genes in the white-rot fungus Pleurotus ostreatus

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    Pleurotus ostreatus is frequently used in molecular genetics and genomic studies on white-rot fungi because various molecular genetic tools and relatively well-annotated genome databases are available. To explore the molecular mechanisms underlying wood lignin degradation by P. ostreatus, we performed mutational analysis of a newly isolated mutant UVRM28 that exhibits decreased lignin-degrading ability on the beech wood sawdust medium. We identified that a mutation in the hir1 gene encoding a putative histone chaperone, which probably plays an important role in DNA replication-independent nucleosome assembly, is responsible for the mutant phenotype. The expression pattern of ligninolytic genes was altered in hir1 disruptants. The most highly expressed gene vp2 was significantly inactivated, whereas the expression of vp1 was remarkably upregulated (300-400 fold) at the transcription level. Conversely, many cellulolytic and xylanolytic genes were upregulated in hir1 disruptants. Chromatin immunoprecipitation analysis suggested that the histone modification status was altered in the 5'-upstream regions of some of the up- and down-regulated lignocellulolytic genes in hir1 disruptants compared with that in the 20b strain. Hence, our data provide new insights into the regulatory mechanisms of lignocellulolytic genes in P. ostreatus

    Increased vesicle fusion competence underlies long-term potentiation at hippocampal mossy fiber synapses

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    Presynaptic long-term potentiation (LTP) is thought to play an important role in learning and memory. However, the underlying mechanism remains elusive because of the difficulty of direct recording during LTP. Hippocampal mossy fiber synapses exhibit pronounced LTP of transmitter release after tetanic stimulation and have been used as a model of presynaptic LTP. Here, we induced LTP by optogenetic tools and applied direct presynaptic patch-clamp recordings. The action potential waveform and evoked presynaptic Ca2+ currents remained unchanged after LTP induction. Membrane capacitance measurements suggested higher release probability of synaptic vesicles without changing the number of release-ready vesicles after LTP induction. Synaptic vesicle replenishment was also enhanced. Furthermore, stimulated emission depletion microscopy suggested an increase in the numbers of Munc13-1 and RIM1 molecules within active zones. We propose that dynamic changes in the active zone components may be relevant for the increased fusion competence and synaptic vesicle replenishment during LTP

    The Framework Convention on Tobacco Control (FCTC) and Japanese anti-tobacco measures

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    Japanese anti-tobacco measures are reviewed and checked the relationship between the FCTC and its changes. Japan is making efforts to follow the FCTC, but it is insufficient and present anti-tobacco measures seem to have only a little impact on decreasing smoking rates. More effective measures should be developed for reducing smoking rates and for making smoke-free society
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