Molecular Dissection of TDP-43 as a Leading Cause of ALS/FTLD

TAR DNA binding protein 43 (TDP-43) is a DNA/RNA binding protein involved in pivotal cellular functions, especially in RNA metabolism. Hyperphosphorylated and ubiquitinated TDP-43-positive neuronal cytoplasmic inclusions are identified in the brain and spinal cord in most cases of amyotrophic lateral sclerosis (ALS) and a substantial proportion of frontotemporal lobar degeneration (FTLD) cases. TDP-43 dysfunctions and cytoplasmic aggregation seem to be the central pathogenicity in ALS and FTLD. Therefore, unraveling both the physiological and pathological mechanisms of TDP-43 may enable the exploration of novel therapeutic strategies. This review highlights the current understanding of TDP-43 biology and pathology, describing the cellular processes involved in the pathogeneses of ALS and FTLD, such as post-translational modifications, RNA metabolism, liquid–liquid phase separation, proteolysis, and the potential prion-like propagation propensity of the TDP-43 inclusions.     

Heat transfer enhancement in duct with blunt body inserted close to its wall

This paper shows the effects of clearance length between a body and a duct wall, and duct height on the heat transfer characteristics and flow behavior at a downstream region of the body when a blunt body was set in a parallel plate duct with some distance separating it from the duct wall as a turbulence promoter. For the ratio of clearance to body height, C/D = 0.05–01, the heat transfer was characterized by the reattachment of shear flow separated from the body. Furthermore, the heat transfer depended on both the reattachment flow and the separation vortex at C/D = 0.15–0.2, and the side vortex induced by Karman vortex at C/D = 0.25–0.275 was also observed. We found the reattachment flow gives a superior effect to enhance heat transfer at a low Reynolds number, but at a larger Reynolds number, the side vortex induced by Karman vortex becomes more effective to heat transfer enhancement. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(5): 336–349, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20067     

Development of 72‐kV high‐pressure air‐insulated GIS with vacuum circuit breaker

SF₆ gas has excellent dielectric strength and interruption performance. For these reasons, it has been widely used for gas‐insulated switchgear (GIS). However, use of SF₆ gas has become regulated under agreements set at the 1997 COP3. Thus, investigation and development for GIS with a lower amount of SF₆ gas are being carried out worldwide. Presently, SF₆‐free GIS has been commercialized for the 24‐kV class. Air or N₂ gas is used as the insulation gas for this GIS. On the other hand, SF₆‐free GIS has not been commercialized for the 72‐kV‐class GIS. The dielectric strengths of air and N₂ gas are approximately one‐third that of SF₆ gas. To enhance the insulation performance of air and N₂ we have investigated a hybrid gas insulation system which has the combined features of providing an insulation coating and suitable insulation gas. We have developed the world's first 72‐kV SF₆‐free GIS. This paper deals with key technologies for SF₆‐free GIS, such as the hybrid insulation structure, a bellows for the high‐pressure vacuum circuit breaker, a newly designed disconnector and spacer, and prevention of particle levitation. Test results of the 72‐kV high‐pressure air‐insulated GIS with the vacuum circuit breaker are described. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(4): 13–23, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20451     

Defect structure and electrical conductivity in rapidly-quenched and slowly-cooled rhombohedral solid solutions of the system Bi2O3-BaO

The solid solubility limit, grain orientation, defect structure and electrical conductivity of solidified rhombohedral specimens in the Bi₂O₃-BaO system are described. The c-axes (in hexagonal notation) of solidified specimens were almost entirely oriented along the platelet/film thickness. Slow-cooling (∼ 10⁻²° Csec⁻¹) of the system gave solid solutions with substitutional type of 2BaO → 2Ba_Bi′ + 20+ V ₀ ^.. for 12 to 32 mol % BaO. High-temperature modification of slowly-cooled sample (16 mol % BaO) showed a conductivity of 8.8×10⁻¹ Ω⁻¹ cm ⁻¹ at 600° C along the conduction plane (perpendicular to the c-axis). Rapid quenching (∼ 10⁵° C sec⁻¹) produced solid solutions for 8 to 20 mol % BaO introducing interstitial Ba²⁺ (10–12 mol % BaO) and Schottky type defects such as V_Bi‴ and V _Bi ^‴ and V ₀ ^.. (16 to 20 mol % BaO), however the high-temperature modification of the rhombohedral structure could not be frozen.     

Temperature dependency of bound water of cellulose studied by a high-resolution NMR spectrometer

The widths at half-value of high-resolution NMR spectra of bound water of cellulose were studied in relation to the temperature change. Two points were made clear: First, the amount of bound water of the cellulose sample can be pointed out with higher accuracy the lower the temperature of the measurement. Second, it is possible to determine in a simple manner the boundary temperature T_c at which water molecules become bound by the cellulose. T_c is characteristic of the cellulose sample of a given water content and corresponds to the glass transition temperature of the water-containing sample. The measurements appear to be readily applicable to other hydrophilic polymers.     

Hydrolysis of dextrin in the presence of 12-tungstosilicic acid

Hydrolysis of dextrin in the presence of 12-Tungstosilicic acid was investigated, and the acid was found to show an approximately two times higher catalytic activity than did hydrochloric acid. From the comparison of degree of dissociation of 12-tungstosilicic acid with that of hydrochloric acid, examination of the influence of the ionic strength on the reaction rates, analysis of the reaction products, and evaluation of activation parameters of the reaction, it was assumed in conclusion that the higher catalytic activity of 12-tungstosilicic acid resulted from a “concentration effect” due to the complex formation of the heteropolyanions with dextrin molecules, and from the effect of its higher ionic strength, but not from the effect of direct participation of the heteropolyanion to the elementary reaction process.     

Catalytic action of metallic salts in autoxidation and polymerization: 11. Polymerization of methacrylic acid esters with sodium hexanitrocobaltate in methanol-water

The polymerization of a series of methacrylic acid esters (methyl, ethyl, isopropyl and n-butyl) with sodium hexanitrocobaltate, Na₃[Co(NO₂)₆] was carried out in a methanol-water mixed solvent. The homogeneity of the polymerization system was dependent on the composition of the mixed solvent and greatly affected the rate of the polymerization. A maximum rate was obtained at approximately equimolar fractions of methanol and water in the polymerization of methyl methacrylate. The effect of bulkiness of ester groups on the polymerizability of each monomer was indistinguishable in the mixed solvent system. Kinetic study of the polymerization of methyl methacrylate in a mixed solvent of about an equimolar fraction of methanol and water gave the following polymerization equation: $\text{R}{}_{\mathrm{p}}\text{= k[l]}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{[}\text{M}\text{]}{}^2$, and an apparent activation energy of 10.6 kcal/mol. The copolymerization of methyl methacrylate and styrene with the initiator suggested that polymerization proceeded via a radical mechanism. The possibility of a certain interaction between initiator, solvent and monomer in the initial stage of the polymerization is discussed on the basis of the kinetic data, properties of oligomers of methyl methacrylate, spectroscopic and other data.     

Lateral growth of GaAs on patterned {-1-1-1}B substrates for the fabrication of nano wires using metalorganic molecular beam epitaxy

We have grown GaAs nano wire structures (45 × 20 nm²) buried in AIAs layers by lateral metalorganic molecular beam epitaxy on the terraced sidewalls of mesa-grooved (-1-1-1)B substrates. The growth of GaAs occurred primarily on the sidewall of the mesa-grooves and not on the (-1-1-1)B surface for arsenic pressures greater than 2.0 × 10⁻³ Pa at a substrate temperature of 480°C. An (0-1-1) facet formation during the lateral epitaxy at the intersection region between the bottom (-1-1-1)B surface and the (1-2-2)A sidewall has been directly observed by real-time scanning microprobe reflection high-energy electron diffraction. The growth rate on the (0111) facet was estimated from the variation of its width with growth time.     

Studies on the ability of cellulosic materials to initiate graft copolymerization

The activity to initiate graft copolymerization was investigated for various cellulose samples. Oxidation of the sample with hydrogen peroxide or sodium hypochlorite indicated a remarkable increase in the per cent grafting as well as the number of grafts. This phenomenon must be attributed to the formation of special reactive groups in cellulosic materials. However, the treatment with hot water caused a definite decrease in the per cent grafting or the number of grafts for the graft copolymerization on the sample, indicating a lower activity to initiate graft copolymerization. Accordingly, the reactive groups, once formed on the sample by oxidation, seemed to be easily decomposed by hot water. The ferric ion adsorbed on cellulose increased the per cent grafting and accelerated the formation of grafts, and the contribution of metallic ions to the initiation was recognized as one of the important factors of graft copolymerization.     

New power consolidation-inversion-control system for faraday MHD generator

The authors propose a new power consolidation-inversion-control system for the Faraday MHD generator using the voltage source PWM inverters. The dc output power for each electrodes pair of the MHD generator is at first inverted into three-phase ac power by a voltage source PWM inverter, and then the ac powers are consolidated by transformers. The proposed system does not need such expensive equipment as an ac filter or phase modifier and can independently and simultaneously control the active and reactive powers provided to the electric power system. Numerical simulations of the whole system, including the Faraday MHD generator, the proposed power consolidation-inversion-control system, and the electric power system, show that the proposed system can stably and steadily transmit and control the electric power from the MHD generator to the electric power system. It is also confirmed that the proposed system can independently and simultaneously control the active and reactive powers and can be used as a fast power controller.