Development of Microstructures of Long-Period Stacking Ordered Structures in Mg85Y9Zn6 Alloys Annealed at 673 K (400 °C) Examined by Small-Angle X-Ray Scattering

Development of LPSO structure and in-plane ordering during annealing the Mg85Y9Zn ternary alloy sample at 673 K (400 °C) was examined by synchrotron radiation small-angle scattering/diffraction measurements. By examining the first diffraction peaks for 18R, 10H, and in-plane order spot, the growth kinetics of in-plane order domain and the transition from 10H into 18R were discussed. The domain growth of in-plane order was characterized by small domain with little correlation between neighboring segregation layers.     

Fast-scanning atomic force microscopy reveals the molecular mechanism of DNA cleavage by ApaI endonuclease

Newly developed fast-scanning atomic force microscopy (AFM) allows the dissection of molecular events such as DNA-enzyme reactions at the single-molecule level. With this novel technology, a model is proposed of the DNA cleavage reaction by a type IIP restriction endonuclease ApaI. Detailed analyses revealed that ApaI bound to DNA as a dimer and slid along DNA in a one-dimensional diffusion manner. When it encountered a specific DNA sequence, the enzyme halted for a moment to digest the DNA. Immediately after digestion, the ApaI dimer separated into two monomers, each of which remained on the DNA end and then dissociated from the DNA end. Thus, fast-scanning AFM is a powerful tool to aid the understanding of protein structures and dynamics in biological reactions at the single-molecule level in sub-seconds.     

Phase unwrapping method for three-dimensional stress analysis by scattered-light photoelasticity with unpolarized light

In scattered-light photoelasticity with unpolarized light, the secondary principal stress direction psi and the relative phase retardation rho in a three-dimensional stressed model with rotation of the principal stress axes can be obtained by use of Stokes parameters. For completely automated stress analysis, measurements of the total relative phase retardation and the secondary principal stress direction over the entire field are required, and it is necessary to unwrap psi and rho. A phase unwrapping method is thus proposed for the determination of these values based on scattered-light photoelasticity. The values are easily obtained via an arctangent function, overcoming the error associated with the quarter-wave plate by employing an incident light of different wavelengths. The proposed technique provides automated and nondestructive determination of the total relative phase retardation and the secondary principal stress direction in a model exhibiting rotation of the principal stress axes.     

Possible explanation for trapped field enhancement on REBaCuO bulk by modified multi-pulse technique with stepwise cooling (MMPSC)

The time evolutions of the local fields B_L(t) have been measured on the surface of the superconducting bulk disk magnetized by a two-stage pulse-field magnetizing technique, called a modified multi-pulse technique combined with stepwise cooling (MMPSC), and the magnetic flux movement and the flux trapping have been investigated. The optimum concaved (“M-shaped”) trapped field profile, which is a necessary condition at the first stage to enhance the final trapped field B_T, makes a larger magnetic gradient (dB/dx) at the bulk periphery in the ascending stage of the applied magnetic pulse at the second stage due to the large viscous force F_v. The magnetic fluxes, which stay at the bulk periphery, start to flow to the center of the bulk, after the applied pulse field reaches a maximum, at which the flux velocity v is nearly zero and then F_v decrease. As a result, a large number of the magnetic fluxes are trapped at the bulk center. The effect of the “M-shaped” profile at the first stage in MMPSC on the enhancement of B_T is discussed.     

A novel brain-specific isoform of beta spectrin: isolation and its interaction with Munc13

Munc13 is a component of the neurotransmitter release machinery which is specifically expressed in brain. Munc13 interacts with Doc2 and syntaxin which are also implicated in the neurotransmitter release process. Here we isolated another Munc13-interacting molecule from a rat brain cDNA library by use of the yeast two-hybrid system, identified it to be a novel type of beta spectrin, and named it beta SpIII sigma 1. beta SpIII sigma 1 was specifically expressed in brain, where it was enriched in the synaptic vesicle and plasma membrane fractions. Because spectrin has been shown to interact with the actin cytoskeleton which is involved in the exocytotic process, the present results suggest that the Munc13-beta SpIII sigma 1 interactions play a role in neurotransmitter release.     

Performance Evaluation of Magnetostrictive Small Wind Turbines Using Fe–Co Alloy–Based Clad Sheets

In this study, the Fe–Co alloy is combined with cobalt ferrite (CoFe₂O₄) and nickel (Ni) to form Fe–Co/CoFe₂O₄ and Fe–Co/Ni clad sheets and their energy-harvesting performance is evaluated. The Fe–Co/CoFe₂O₄ clad sheet exhibits an output voltage of 4.229 mV and an output power of 6.89 nW at a wind speed of 10 m s⁻¹. The energy-harvesting performance of both these clad sheets cannot be quantitatively compared owing to their different thicknesses, which result in varying volume and distance from the neutral plane. Nevertheless, the values of output voltage and power for Fe–Co/CoFe₂O₄ are higher than those for Fe–Co/Ni (2.107 mV and 0.294 nW).     

Bio-Inspired Adhesive with Reset-On Demand,Reuse-Many (RORM) Modes

Development of tough, reusable adhesives is important, but remains a major challenge, especially in water. A tough reusable adhesive that resets entirely to its virgin condition when needed is reported using caffeic acid. Here, caffeic acid is employed as adhesive moiety to achieve such the functions due to its dual characteristics: an adhesive moiety from mussel-inspired catechol and a photo-reversible crosslink from cinnamic acid. Adhesion involves a two-step process. First, the caffeic acid-functionalized polymer is applied to the adherend, followed by UV irradiation (peak wavelength of light-emitting diode, λ_P: 365 nm) to form a durable pre-applied adhesive (PAA) layer through crosslinking among the caffeic acid moieties. Second, thermal activation of the PAA layer ensures repeated adhesion to a variety of adherends ( R euse- M any mode). The cyclic dimer of the caffeic acid moiety is de-crosslinked by UV irradiation at λ_P: 254 nm. This allows the complete removal of the adhesive residues from the adherends when the adhesive is no longer needed ( R eset- O n demand mode). Furthermore, using magnetic nanoparticles, the caffeic acid-functionalized polymer can be activated remotely under water by magnetic induction heating. This study paves the way for the rational design of bio-inspired adhesives that outperform nature using plant-derived raw materials.     

Wet milling synthesis of ammonium cobalt phosphate hydrate platelets for LCP-olivine cathodes of LIBs using a bead mill

In this study, NH₄CoPO₄·H₂O (ACP) platelets were synthesized from NH₄H₂PO₄ and Co(OH)₂ by wet milling process using a bead mill. ACP is one of the precursors of LiCoPO₄ (LCP) cathode materials for Li-ion batteries. In the wet milling, ACP large platelets were synthesized in a short time at the beginning, and the large platelets were gradually cleaved into the smaller platelets. The lateral sizes of the ACP platelets were several 10 μm at 30 min and about 10 μm at 5 h. It was found that the ACP platelets were synthesized efficiently by using the bead mill as a promising machine for the scale-up in manufacturing. The ACP platelets were converted into LCP by mixing with Li₂CO₃ and heating, whereas platelet shapes were retained. The initial discharge capacities of the cathodes using the LCP platelets converted from the ACP of 30 min and 5 h milling were 70 and 95 mAh/g at 0.05 C, respectively. It is because the specific surface area of the latter sample (3.3 m²/g) was larger than that of the former (2.2 m²/g). The larger specific surface area possibly led to the increase of contacts with electron conductive additives (carbon) and electrolytes.     

Rapid synthesis of YAG phosphor by facile mechanical method

In this study, synthesis of yttrium aluminum garnet (YAG):Ce³⁺ phosphor powders for white light emitting diodes was investigated by mechanical method using the attrition-type mill with no external heating and no flux in dry phase. High mechanical energy input to the starting powder mixture of Y₂O₃, Al₂O₃ and CeO₂ achieved the synthesis of YAG:Ce³⁺ without any flux materials. X-ray diffraction patterns of the processed powders after 5 min processing revealed the peaks of YAG were clearly identified. The maximum temperature of the mill chamber during the processing was 240℃. The YAG phosphor obtained by the mechanical method revealed the internal quantum yield of 65% in the case of the sample mechanically processed under a reducing atmosphere. The synthesized powder showed granule structure consisting of submicron size of YAG particles, which is better handling for the fabrication of light emitting diode devices.     

Synthesis of Short Peptides with Perfluoroalkyl Side Chains and Evaluation of Their Cellular Uptake Efficiency

With an increasing demand for macromolecular biotherapeutics, the issue of their poor cell-penetrating abilities requires viable and relevant solutions. Herein, we report tripeptides bearing an amino acid with a perfluoroalkyl (R_F) group adjacent to the α-carbon. R_F-containing tripeptides were synthesized and evaluated for their ability to transport a conjugated hydrophilic dye (Alexa Fluor 647) into the cells. R_F-containing tripeptides with the fluorophore showed high cellular uptake efficiency and none of them were cytotoxic. Interestingly, we demonstrated that the absolute configuration of perfluoroalkylated amino acids (R_F-AAs) affects not only nanoparticle formation but also the cell permeability of the tripeptides. These novel R_F-containing tripeptides are potentially useful as short and noncationic cell-penetrating peptides (CPPs).