Composite of Au nanoparticles and molecularly imprinted polymer as a sensing material

A molecularly imprinted polymer with immobilized Au nanoparticles (Au-MIP) is reported as a novel type of sensing material. The sensing mechanism is based upon the variable proximity of the Au nanoparticles immobilized in the imprinted polymer, which exhibits selective binding of a given analyte accompanied by swelling that causes a blue-shift in the plasmon absorption band of the immobilized Au nanoparticles. Using adrenaline as the model analyte, it was shown that molecular imprinting effectively enhanced the sensitivity and selectivity, and accordingly, Au-MIP selectively detects the analyte at 5 microM. The combination of molecular imprinting and the Au nanoparticle-based sensing system was shown to be a general strategy for constructing sensing materials in a tailor-made fashion due to wide applicability of the imprinting technique and the independence of the sensing mechanism from the analyte recognition system.     

Retardation‐controlling color filter with two directly stacked retardation layers

Abstract— A polymerizable liquid crystal (PLC), the orientation of which can be frozen, is useful for making retardation layers. In this paper, a new color filter (CF) with retardation‐controlling layers made of PLC is reported. It has a positive A‐plate and a negative C‐plate, both directly stacked on a color‐filter layer. These two retardation layers exhibit good orientation ability, and function well as retarders, even when they are only 1/10 or less as thick as ordinary retardation films. The new CF also has excellent thermal stability. The change in retardation after heat treatment at 200°C for 30 min is around 5%, and there is no observable peeling. A prototype VA‐LCD made with our new CF provides good optical compensation, with the light leakage being extremely low in all azimuthal directions. This technology is very useful for making thin, highly reliable color filters for LCDs, even with other modes.     

Facile one-step route to polyaniline–silver nanocomposite particles and their application as a colored particulate emulsifier

Polyaniline–silver nanocomposites were synthesized in the form of colloidal particles by the facile one-step aqueous chemical oxidative dispersion polymerization of aniline using silver nitrate as an oxidant and poly(vinyl alcohol) as a colloidal stabilizer. Aniline monomer was oxidized by silver ions, yielding polyaniline and elemental Ag simultaneously. The synthesized nanocomposite particles were colloidally stable over 2 years and transmission electron microscopy studies indicated the production of spherical, plate and rod-shaped polyaniline–silver nanocomposite particles with a silver core–polyaniline shell morphology. The conductivity of a pressed pellet of the nanocomposite particles using the conventional four-point probe technique was 1.4 × 10^?2 S/cm at 25 °C. The nanocomposite particles behaved as a ‘colored’ particulate emulsifier for the stabilization of transparent oil-in-water emulsions.     

Numerical computation on the control of aerial flow by the magnetizing force in gravitational and nongravitational fields

Two-dimensional numerical computations were carried out in order to examine the effect of magnetizing force for the air in a cylindrical container with thermal and magnetic field gradients. In a gravitational field, the air was driven by both gravitational and magnetizing forces, and flow pattern and the heat transfer rate greatly depended on the axial position of the coil. Moreover, when the magnetizing and gravitational forces cancel out each other, convection became almost quiescent. On the other hand, the aerial flow was induced by the magnetizing force even in a nongravitational field, and the air behaved like an electrically conducting fluid.     

Role of transverse temperature gradients in the generation of lamellar eutectic solidification patterns

In directional solidification, a sample is pulled in an externally imposed temperature gradient. When the pulling direction and the temperature gradient are not perfectly aligned, a transverse temperature gradient is generated in the sample. We investigate the dynamics of lamellar eutectic patterns, both by experimental observations and by numerical simulations, and find that it is dramatically affected by a transverse gradient. Whereas, in its absence, the labyrinth patterns that are formed in the initial stage of solidification persist over the entire duration of the experiments, a transverse temperature gradient induces a drift of the pattern which rapidly generates a regular array of lamellae. The drift speed is found to be consistently larger than expected from the normal growth hypothesis, both in simulations and experiments.     

Recycling of aluminum matrix composites

Separation of matrix metals in composites was tried on alumina short fiber-reinforced aluminum and 6061 alloy composites and SiC whisker-reinforced 6061 alloy composite for recycling. It is possible to separate molten matrix metals from fibers in the composites using fluxes that are used for melt treatment to remove inclusions. About 50 vol pct of the matrix metals was separated from the alumina short fiber-reinforced composites. The separation ratio of the matrix from the SiC whisker-reinforced 6061 alloy composite was low and about 20 vol pct. The separation mechanism was discussed thermodynamically using interface free energies. Since the flux/fiber interface energy is smaller than the aluminum/fiber interface energy, the replacement of aluminum with fluxes in composites takes place easily. Gases released by the decomposition of fluxes act an important role in pushing out the molten matrix metal from the composite. The role was confirmed by the great amount cavity formed in the composite after the matrix metal flowed out.     

Tubulin Photoaffinity Labeling with Biotin‐Tagged Derivatives of Potent Diketopiperazine Antimicrotubule Agents

NPI‐2358 ( 1 ) is a potent antimicrotubule agent that was developed from a natural diketopiperazine, phenylahistin, which is currently in Phase I clinical trials as an anticancer drug. To understand the precise recognition mechanism of tubulin by this agent, we focused on its potent derivative, KPU‐244 ( 2 ), which has been modified with a photoreactive benzophenone structure, and biotin‐tagged KPU‐244 derivatives ( 3 and 4 ), which were designed and synthesized for tubulin photoaffinity labeling. Introduction of the biotin structure at the p′‐position of the benzophenone ring in 2 exhibited reduced, but significant biological activities with tubulin binding, tubulin depolymerization and cytotoxicity in comparison to the parent KPU‐244. Therefore, tubulin photoaffinity labeling studies of biotin‐derivatives 3 and 4 were performed by using Western blotting analysis after photoirradiation with 365 nm UV light. The results indicated that tubulin was covalently labeled by these biotin‐tagged photoprobes. The labeling of compound 4 was competitively inhibited by the addition of diketopiperazine 1 or colchicine, and weakly inhibited by the addition of vinblastine. The results suggest that photoaffinity probe 4 specifically recognizes tubulin at the same binding site as anticancer drug candidate 1 , and this leads to the disruption of microtubules. Probe 4 serves well as a useful chemical probe for potent antimicrotubule diketopiperazines, much like phenylahistin, and it also competes for the colchicine‐binding site.     

Deep-submicrometer CMOS technology with reoxidized or annealednitrided-oxide gate dielectrics prepared by rapid thermalprocessing

Deep submicrometer CMOSFETs with re-annealed nitride-oxide gate dielectrics have been demonstrated to satisfy 3.3-V operation, unlike conventional oxide FETs. The 1/4-μm re-annealed nitrided-oxide CMOS devices achieve (1) an improved saturation transconductance g _m of ~250 μS/μm for n-FETs together with acceptably small degradation in p-FET g_m resulting in a CMOS gate delay time of 55 ps/stage comparable or superior to the device/circuit performance of oxide FETs, and (2) device lifetimes improved by ~100 times to exceed 10 years with respect to both ON- and OFF-state hot-carrier reliability for n-FETs as well as gate-dielectric integrity together with unchanged p-FET hot-carrier reliability, all at 3.3-V operation. To achieve these CMOS performance/reliability improvements, both a light nitridation and subsequent re-annealing in O ₂ (reoxidation) or in N₂ (inert-annealing) are found to be crucial     

The influence of combined visual and tactile information on finger and eye movements during shape tracing.

Adaptation experiments in shape tracing were conducted to investigate finger and eye movements in various conditions of visual and tactile information. Maximum velocity, mean velocity, maximum acceleration and reacceleration point were calculated from finger movements. Number of eye fixations and lead time of eye fixation to finger position were calculated from eye movements. The results showed that for the finger movement the values of the indices studied were higher in the combined visual and tactile condition than in the visual only condition. The number of eye fixations decreased when subjects repeated the tracing and was more marked in the combined visual and tactile condition than in the visual only condition. The results suggest that finger movements become faster and use of vision is reduced when both visual and tactile information are given.