304 research outputs found
Advanced aging effects on implicit motor imagery and its links to motor performance: An investigation via mental rotation of letters, hands, and feet
This study focuses on changes in implicit motor imagery during advanced aging and these changes’ co-occurrences with physical motor deficits. We administered a mental rotation (MR) task with letters, hands, and feet to 28 young adults (20–27 years) and to 71 older adults (60–87 years), and assessed motor skills (gait mobility and hand dexterity) and neuropsychological performance. Compared to young adults, older adults showed lower MR performance for all stimuli and stronger biomechanical constraint effects on both hand and foot rotation. Moreover, the foot biomechanical constraint effect continued to increase during late adulthood, and declines in hand and foot motor imagery emerged at earlier old ages than declines in visual imagery. These results first demonstrated distinct aging trajectories of hand motor imagery, foot motor imagery, and visual imagery. Exploratory partial correlation analysis for older adults showed positive associations of low-level perceptual-motor skills (Trail Making Test-A performance) with hand and foot MR performance and positive associations of mobility (Timed Up and Go test performance) with foot and letter MR performance. These associations exhibited somewhat different patterns from those of young adults and raised the possibility that age-related declines in motor (and visual) imagery co-occur with declines in motor functioning
An Attempt to Measure the Familiarity of Specialized Japanese in the Nursing Care Field
Having a firm grasp of technical terms is essential for learners of Japanese for Specific Purposes (JSP). This research aims to analyze Japanese nursing care vocabulary based on objective corpus-based frequency and subjectively rated word familiarity. For this purpose, we constructed a text corpus centered on the National Examination for Certified Care Workers to extract nursing care keywords. The Log-Likelihood Ratio (LLR) was used as the statistical criterion for keyword identification, giving a list of 300 keywords as target words for a further word recognition survey. The survey involved 115 participants of whom 51 were certified care workers (CW group) and 64 were individuals from the general public (GP group). These participants rated the familiarity of the target keywords through crowdsourcing. Given the limited sample size, Bayesian linear mixed models were utilized to determine word familiarity rates. Our study conducted a comparative analysis of word familiarity between the CW group and the GP group, revealing key terms that are crucial for professionals but potentially unfamiliar to the general public. By focusing on these terms, instructors can bridge the knowledge gap more efficiently
Long-range cooperative binding of kinesin to a microtubule in the presence of ATP
Interaction of kinesin-coated latex beads with a single microtubule (MT) was directly observed by fluorescence microscopy. In the presence of ATP, binding of a kinesin bead to the MT facilitated the subsequent binding of other kinesin beads to an adjacent region on the MT that extended for micrometers in length. This cooperative binding was not observed in the presence of ADP or 5′-adenylylimidodiphosphate (AMP-PNP), where binding along the MT was random. Cooperative binding also was induced by an engineered, heterodimeric kinesin, WT/E236A, that could hydrolyze ATP, yet remained fixed on the MT in the presence of ATP. Relative to the stationary WT/E236A kinesin on a MT, wild-type kinesin bound preferentially in close proximity, but was biased to the plus-end direction. These results suggest that kinesin binding and ATP hydrolysis may cause a long-range state transition in the MT, increasing its affinity for kinesin toward its plus end. Thus, our study highlights the active involvement of MTs in kinesin motility
Selective preparation of zero- and one-dimensional gold nanostructures in a TiO2 nanocrystal-containing photoactive mesoporous template
Nanocrystallized SiO2-TiO2 with tubular mesopores was prepared via the sol-gel technique. Gold was deposited in the tubular mesopores of the nanocrystallized SiO2-TiO2. The shape of the gold was varied from one-dimensional [1-D] to zero-dimensional [0-D] nanostructures by an increase in TiO2 content and ultraviolet [UV] irradiation during gold deposition. 1-D gold nanostructures [GNSs] were mainly obtained in the mesopores when a small amount of TiO2-containing mesoporous SiO2-TiO2 was used as a template, whereas the use of a template containing a large amount of TiO2 led to the formation of shorter 1-D or 0-D GNSs. UV irradiation also resulted in the formation of 0-D GNSs
FABRICATION OF POROUS, CRYSTALLINE-ORIENTED TITANIA LAYER ON TRANSPARENT ELECTRODE BY MAGNETIC FIELD-ASSISTED EPD
Dye-sensitized solar cells (DSSCs) are the most extensively investigated systems for the conversion of solar energy into electricity, since it can convert light at longer wavelengths into electricity and can be manufactured using less energy compared to the bulk semiconductor-type cells with a p-n junction. Despite these advantages, DSSC commercialization is still limited because of its low conversion efficiency and low reliability of the liquid electrolyte. The low conversion efficiency is due to the non-uniformity of the electrode components with respect to the packing density of TiO2 particles and film thickness of the electrode. Therefore the research on DSSC in general has been directed toward improving the photo-current and photo-potential. In order to significantly enhance the cell performance, it is important to optimize the photo-anode structure of the DSSC on the basis of its fundamental properties. In this study, crystalline-oriented porous TiO2 thin films were fabricated on indium-tin oxide (ITO) or fluorine-doped tin oxide (FTO) glass substrates by electrophoretic deposition (EPD) in a superconducting magnet.
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Electrophoretic deposition of Ag nanoparticles into TiO2 nanotube arrays and their performance as photoanode of dye-sensitized solar cells
Dye-sensitized solar cells (DSSCs) are known as next-generation solar cells because their production process costs low and is environmentally friendly compared to silicon-type solar cells, which are currently most widely used in the world. However, power conversion efficiency (PCE) of DSSCs is still lower than 12%, which is much lower than that of silicon-type solar cells. Since one of the main reasons of such a low PCE of DSSCs is a weak light absorption ability of dye molecules, researchers have been studying to improve the light harvesting ability of DSSCs by, for instance, producing new dyes, designing new DSSC structures, adding light absorbing/scattering elements/materials, etc. The addition of metal nanoparticles (NPs) to an photoanode is one of the ways to improve light harvesting ability of DSSCs, because the NPs exhibit surface plasmon resonance (SPR) which absorb and scatter light strongly. SPR is a collective oscillation of free electrons of metal, thus strong electro-magnetic (EM) field is created near the surface of metal NPs. The electrons of dyes can be easily excited by the enhanced EM field and thus the PCE of DSSCs improved. However, the improvement of PCE of DSSCs by metal NPs is generally not as high as expected, because it is difficult to control dispersion state of metal NPs in an photoanode.
In this work, Ag NPs were used as metal NPs because Ag NPs are known to create the strongest EM field by SPR among all metals. Anodic TiO2 nanotube (TNT) arrays were employed as a photoanode since the morphology of TNT arrays is known to be appropriate to reduce an electrical resistivity at photoanode. Several methods of Ag NP deposition on TNT arrays were investigated for controlling the dispersion state of Ag NPs
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SHEAR ZONE DEVELOPMENT AND FRICTIONAL INSTABILITY OF FAULT GOUGE
ABSTRACT: Earthquakes are typical phenomena of frictional slip of geomaterials in nature. To evaluate slip instability, shear development in a gouge layer or fault material has been investigated. However, the quantitative relationship between slip instability and shear development has not been revealed because of difficulty in quantitative observation of microstructures under high pressure. Hence, we aim to describe shear development in a gouge layer energetically, and discuss the relation between shear development and slip instability. To this end, we calculated shear angles by utilizing experimental data of gouge. As a result, this study reveals that shear bands in a gouge layer develop at lower angles or almost parallel to rock-gouge boundaries toward the occurrence of unstable slip, particularly under low confining pressure. Additionally, variation in Riedel shear angles throughout gouge layers depends on confining pressures: Under low confining pressures, heterogeneous localized shears trigger voluntary increase in strain. On the other hand, under a high confining pressure, gouge layers deform homogeneously, and the whole of samples slips dynamically. Clarification of shear development of geomaterials is useful for evaluating the occurrence of frictional slip such as earthquakes and slope failures
EPD FOR COMPOSITE CATHODE LAYER IN ALL-SOLID-STATE LITHIUM ION BATTERY BASED ON SULFIDE ELECTROLYTE
All-solid-state lithium ion batteries (LIBs), in which liquid-organic electrolytes are replaced with solid state inorganic electrolytes, are expected to be the optimal rechargeable batteries in the next generation because of their higher energy density, cycle stability and ignition safety. In order to develop all-solid-state LIBs with practical performance, controlling architecture in electrode layer consisting of active materials and solid electrolyte, to obtain good contact of the solids interfaces, with high packing ratio is necessary. However, there are few studies on controlled fabrication of macrostructure. We would like to propose a novel method which is employs electrophoretic deposition (EPD) for preparing composite cathode layer, with LiNi1/3Mn1/3Co1/3O2 (NMC) and 75Li2S-25P2S5 (LPS) used as the cathodic active material and solid electrolyte, respectively. The EPD technique can be used to prepare a cathodic layer with a desired structure because its equipment set up is simple but can be used to obtain complex composite structures.
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