Visualization and Quantification of Vascular Structure of Fruit Using Magnetic Resonance Microimaging

Three-dimensional magnetic resonance (MR) images of four kinds of fruit (Japanese apricot, peach, Japanese pear, and apple) were acquired throughout their growing periods (from April to August) to visualize and quantify their vascular structures. The vascular structures were emphasized using T ₁-weighted spin-echo or gradient-echo pulse sequences, visualized using a maximum-intensity projection technique, and quantified using an image-segmentation program. As a result, we demonstrated that the vascular volume changed almost in proportion to the whole volume and that larger fruits generally had larger proportionality constants. We therefore concluded that MR microimaging is a powerful tool for studies of the vascular structure of fruit.     

Acoustoelastic stress analysis of residual stress in a patch-welded disk

The acoustoelastic stress analysis is based on the fact that an initially isotropic material becomes anisotropic under stress. The birefringent effect for polarized ultrasonic shear waves in the stressed material will then be similar to the photoelastic effect in which a light wave and a transparent model specimen are used. In this paper, the velocity differences of acoustical, perpendicularly polarized waves are measured directly by a ‘sing-around’ method using a 5-MHz shear-type transducer. The residual-stress distribution in a mild-steel circular plate with a concentrically patch-welded joint is measured by this method. The acoustoelastic coefficient is obtained separately by uniaxial testing of the base material. The results show that the acoustical stress measurement, carried out nondestructively, agrees well with those obtained by conventional destructive methods as well as with theoretical predictions.     

Reactivity of Hydroxy‐ and Aquo(hydroxy)‐λ3‐iodane–Crown Ether Complexes

We have designed a series of hydroxy(aryl)‐λ³‐iodane–[18]crown‐6 complexes, prepared from the corresponding iodosylbenzene derivatives and superacids in the presence of [18]crown‐6, and have investigated their reactivities in aqueous media. These activated iodosylbenzene monomers are all non‐hygroscopic shelf‐storable reagents, but they maintain high oxidizing ability in water. The complexes are effective for the oxidation of phenols, sulfides, olefins, silyl enol ethers, and alkyl(trifluoro)borates under mild conditions. Furthermore, hydroxy‐λ³‐iodane–[18]crown‐6 complexes serve as efficient progenitors for the synthesis of diaryl‐, vinyl‐, and alkynyl‐λ³‐iodanes in water. Other less polar organic solvents, such as methanol, acetonitrile, and dichloromethane, are also usable in some cases.     

Fluorogenic aldehydes bearing arylethynyl groups: turn-on aldol reaction sensors for evaluation of organocatalysis in DMSO

Fluorogenic aromatic aldehydes bearing arylethynyl groups were developed. They were used for monitoring the reaction progress of organocatalytic aldol reactions in DMSO through an increase in the fluorescence intensity based on the formation of the florescent aldol product. The ratios of the fluorescence intensities of the aldols to the aldehydes were more than 300. These results suggest that the fluorescence assay system using the aldehyde is useful for the rapid identification of superior aldol catalysts and reaction conditions.     

Simultaneous acquisition of color and distance information by LiDAR with RGB visible laser diodes

We propose colors light detection and ranging (LiDAR) using visible laser diodes (LD) of red, green, and blue (RGB) colors to identify colors as well as obtain position information of surrounding objects. To verify the principle, we performed round-trip time-of-flight (TOF) measurements by irradiating a target of different colors with pulsed light from a LD of RGB colors. It is clarified that accurate distance measurements of up to 12 m can be realized in any RGB LD, and the received signal in each LD has different intensity characteristics depending on the target color. From a judgment table created from reception intensity characteristics for three types of LD and seven types of color target, the color of each target is successfully identified.

     

Preferential penetration path of gallium into grain boundary in practical aluminium alloy

The preferential penetration of a liquid metal along grain boundaries (GBs) in polycrystalline metals is a well-known phenomenon. Gallium-decorated GB networks in rolled aluminium alloys have been visualized three-dimensionally using the high-resolution synchrotron radiation computer tomography (SRCT). The distribution of gallium concentration along GBs was measured using X-ray absorption. Statistical correction for blurring was performed to raise accuracy of the measurement, and then compared with orientation mapping by the SEM/EBSP method on the surface of a tomographic specimen. The pancake-like grain microstructure formed by a rolling process causes the anisotropy of penetration direction. Although the gallium penetrated into high-angle GBs, all of the high-angle GBs are not necessarily decorated by the gallium. The reason for this may be explained by considering geometrically possible penetration paths that seem to be dependent on local grain arrangement and GB structure through each path. The dependence of the gallium concentration on the rotation axis of misorientation has been found along the high-angle GBs. Especially, GBs with a specific misorientation (〈221〉 as a misorientation axis) showed high gallium concentration.     

Electrochemical flow enzyme immunoassay by means of a needle-shaped sampler/reactor.

A needle-shaped sampler/reactor was developed for an electrochemical enzyme immunoassay with the direct sampling of living sample blood. This device was evaluated using IgG determination chemistry. Antibodies were immobilized on an inner wall of the sampler/reactor. Incubation for the enzyme reaction was not needed because this reactor was very small (250 microm in diameter). The analysis was conducted within 15 min in the simplest protocol including the reactor refreshment. The limit of detection was 3 pg, and 20 attomol in the most sensitive protocol. Furthermore, the sampling of a solution contained in an agar block and a whole-blood analysis were demonstrated.     

Photoreaction of 1H‐azepine‐2,7‐dione in alkaline solution

Photolysis of 1H‐azepine‐2,7‐dione 2 proceeded with alkali as in the photoreaction of N‐alkylimide to give 7‐hydroxy‐1H‐azepine‐2‐one 13 .     

Fabrication of L10 FePtAg nanoparticles and a study of the effect of Ag during the annealing process

L1₀ ferromagnetic phase FePt nanoparticles containing Ag atoms (FePtAg) were synthesized by means of a liquid phase process, followed by annealing. The addition of Ag to FePt nanoparticles permits annealing to be conducted at a lower temperature (350 °C). This is further accompanied by a subsequent transformation in the crystal phase from the FCC superparamagnetic phase to the FCT (L1₀) ferromagnetic phase. The effects of annealing temperature and the Ag atoms inside the nanoparticles on the magnetic properties of the FePt nanoparticles have been studied. Using electron spectroscopy for the chemical analysis (ESCA), Ag atoms in the L1₀ phase FePtAg nanoparticles were found to be localized on the surface region of the annealed nanoparticles. The Ag atoms function to inhibit the oxidation of FePt, causing the particles to become more stable and to have ferromagnetic properties.     

Growth of GaAs nanostructures by area selective epitaxy by migration-enhanced epitaxy

We have carried out area selective epitaxial growth of GaAs nanostructures using solid source molecular-beam epitaxy (MBE) which makes it possible to achieve ‘damage-free’ structures. However, area selective epitaxy by MBE is very difficult unless the substrate temperature is very high. This problem has been solved by using migration-enhanced epitaxy (MEE) deposition sequence. To achieve well-defined nanostructures, lateral growth beyond the SiO₂ mask boundaries has to be strictly prohibited. By MEE method, uniform two-dimensional lattice structures with vertical sidewalls can be fabricated without shrinking holes, even though the mask diameter is as small as 30 nm with a dot density as high as 5.0×10⁹ cm⁻². Also uniform one-dimensional channel structures have been successfully grown.