Shigeyoshi Morisaki

Aluminium detected in senile plaques and neurofibrillary tangles is contained in lipofuscin granules with silicon, probably as aluminosilicate.

Aluminium and silicon are incidentally found in senile plaques (SP) and neurofibrillary tangles (NFT) of brains with Alzheimers disease (AD), and have been considered as one of the risk factors for senile dementia. Since lipofuscin granules were concentrated concomitantly with SP and NFT in the high density fraction in subcellular fractionation of autopsied brains and are solid in nature, it was suspected that aluminum and silicon are accumulated in lipofuscin granules. Therefore, elemental analyses of partially purified lipofuscin granules from autopsied brains with AD and those without dementia, were attempted by energy dispersive X-ray spectrometry with a scanning electron microscope. It was demonstrated by a mapping method that aluminum and silicon were accumulated in some lipofuscin granules, probably as aluminosilicate. In addition, it was demonstrated by fluorescence microscopy of Bodian stained paraffin sections, that many SP and NFT contained lipofuscin granules, although lipofuscin granules were not always specific to those neuropathological changes. These results imply that aluminum detected in SP and NFT is due to lipofuscin granules and can explain the cause of discrepancies in the reports on the presence of aluminum in SP and NFT.

Formation of Nickel Oxyhydroxide Thin Films by Electrodepositon and Their Electrochromic Characteristics

Electrochromic nickel oxyhydroxide films were formed by an electrodeposition method from 0.005 M NiSO4+0.015 M (NH4)SO4 solution, and their memory characteristics, response time and operation lifetime were investigated. The films prepared were porous with a network structure. They were colorless and transparent in a lower oxidation state [Ni(OH)2], but were dark brown in a higher oxidation state [NiOOH]. By heat-treating the films at 250degC for 15 minutes, electrochromic characteristics such as the operation lifetime could be remarkable improved.

Preparation of Electrochromic MoO3 Thin Films on ITO Glasses by Electrodeposition

A new method of formation of electrochromic MoO3 thin oxide film on electric conducting glass (ITO glass) has been investigated for use in place of the conventional vacuum evaporation method. The ITO glass was cathodically electrolyzed in an aqueous solution of 0.007 mol/l lithium molybdate at a constant current density of ca. 3 A/m2 at 25°C. Blue, conductive and adhesive oxide film was obtained. Cycles of the coloration and bleach were repeated in the propylene carbonate solution of lithium perchlorate. A good reversibility was obtained.

X‐ray microprobe analysis of corpora amylacea

Since corpora amylacea is concentrated in the high density fraction in the subcellular fractionation of autopsy brain, it is suspected that inorganic materials accumulate in corpora amylacea. Therefore, elemental analyses of partially purified corpora amylacea from autopsy brain from a patient with Alzheimers disease and those from brain of a non‐demented patient were performed by the X‐ray microprobe method. Prominent peaks of sodium, phosphorus, sulphur and chloride were observed, and mapping analyses confirmed that these elements were actually contained within the corpora amylacea. A similar result was obtained using cryostat sections. Corpora amylacea are characteristically distributed along the margin of blood vessels, beneath the pial border of the hippocampus and in the subependymal zones of ventricles of aged brains, namely in the vicinity of blood and cerebrospinal fluid. From this distribution and from the results of the present paper, we suggest that corpora amylacea play a role in the absorption and accumulation of inorganic materials which have been extravasated from blood and cerebrospinal fluid (CSF) and taken up by astrocytes. This may reflect alteration of the blood‐brain and blood‐CSF barriers in the ageing brain.

Effects of Anodic Electrodeposition Coating on the Structure of Three-Step Coloring Films on Aluminum

Three-step electrolytic coloring of aluminum was carried out by applying sulfuric acid, low-voltage AC anodic oxidization between DC anodic oxidization and electrolytic coloring. The films produced by this three-step electrolytic coloring method were observed using a transmission electron microscope (TEM) and a scanning electron microscope (SEM) to study the influence of anodic electrodeposition (ED) coating on the film structure. AC electrolysis following DC anodic oxidization showed the current recovery phenomenon, and an AC anodizing layer was generated under the DC anodizing layer with the barrier layer remaining. In addition, the thickness of the barrier layer of the AC anodizing layer indicated the simultaneous progress of the metal compound deposit reaction and the formation reaction of the barrier layer for electrolytic coloring. The ED coating did not affect the structure of each anodizing layer greatly, nor did it affect the metal compound deposited in the AC anodizing layer, but the metal compound that was previously deposited unevenly in the DC anodizing layer could no longer be observed using a TEM. The discoloration of the electrolytic colored film with ED coating may not be attributable to a change in the interference distance due to elution of the deposits in the AC anodizing layer or to a change in the thickness of the barrier layer, but rather to a change in the conditions of the metal compound deposited in the DC anodizing layer.

Electroluminescence from Barrier-Type Anodic Oxide Alumina Films Doped with Rare-Earth and Transition Metals by Ion-Implantation

Electroluminescence (EL) during reanodization of a barrier-type anodic oxide alumina film (barrier alumina film) doped with rare-earth and transition metals was observed. To dope the rare-earth and transition metals into the barrier alumina films, an ion-implantation technique was employed. The sharp emissions from the barrier alumina films doped with rare-earth metals were assigned to the 4f–4f transitions of the trivalent elements, with the exception of Ce which was assigned to the 5d–4f transitions. With the doping of multiple elements, the emission spectrum was a mixture of the spectra of all elements, that is, the emission color of each element was mixed to exhibit a certain color.

Electroluminescence of europium ion-implanted aluminum during anodization

Europium-implanted aluminum shows an orange electroluminescence (EL) during anodization in a 0.1 M ammonium pentaborate solution. The emission spectra show that this EL can be ascribed to the 4f-electron transitions of Eu3+ in an Al2O3 films. The EL intensity shows a maximum at a forming voltage of 70 V. The EL mechanism can be related to anodization in an Eu-implanted aluminum surface layer.

Mass Transfer Process by Magneto-convection at a Solid-liquid Interface in a Heterogeneous Vertical Magnetic Field

When an external magnetic field is vertically imposed on a solid–liquid interface, the mass transfer process of a solute dissolving from or depositing on the interface was theoretically examined. In a heterogeneous vertical magnetic field, a material receives a magnetic force in proportion to the product of the magnetic susceptibility, the magnetic flux density B and its gradient (dB/dz). As the reaction proceeds, a diffusion layer of the solute with changing susceptibility is formed at the interface because of the difference of the the magnetic susceptibility on the concentration of the solute. In the case of an unstable condition where the dimensionless number of magneto-convection S takes a positive value, the magnetic force is applied to the layer and induces numerous minute convection cells. The mass transfer of the solute is thus accelerated, so that it is predicted that the mass flux increases with the 1/3rd order of B(dB/dz) and the 4/3rd order of the concentration. The experiment was then performed by measuring the rate of the dissolution of copper sulfate pentahydrate crystal in water.

Blue Luminescence from Divalent Europium Supported by Anodic Alumina

The fluorescence of divalent europium is important in blue luminescence such as that used in plasma displays. This research aimed to develop a useful method for producing divalent europium fluorescence. Anodic alumina was used as a support material and the conditions under which divalent europium is stable were examined. The design of material by DV-Xα molecular orbital simulation and the structure of aluminum oxide in which divalent europium ions are stable were examined. The electroluminescence of divalent europium was confirmed.