Anodic Fluorination,Methoxylation, Acetoxylation,and Cyanation of Heteroatom Organic Compounds Using Boron-Doped Diamond,GC, and Pt Electrodes

Various anodic substitution reactions such as fluorination, methoxylation, acetoxylation, and cyanation of heteroatom compounds containing a sulfur or nitrogen atom were comparatively studied using boron-doped diamond (BDD), Pt, and glassy carbon (GC) anodes. It was found that BDD anode is highly effective for these anodic substitution reactions similarly to Pt anode although both BDD and GC electrodes are carbon-based materials.     

Antisense Oligonucleotide Modified with Disulfide Units Induces Efficient Exon Skipping in mdx Myotubes through Enhanced Membrane Permeability and Nucleus Internalization

We have found that antisense oligonucleotides and siRNA molecules modified with repeat structures of disulfide units can be directly introduced into the cytoplasm and exhibit a suppressive effect on gene expression. In this study, we analyzed the mechanism of cellular uptake of these membrane-permeable oligonucleotides (MPONs). Time-course analysis by confocal microscopy showed that the uptake of MPONs from the plasma membrane to the cytoplasm reached 50 % of the total uptake in about 5 min. In addition, analysis of the plasma membrane proteins to which MPONs bind, identified several proteins, including voltage-dependent anion channel. Next, we analyzed the behavior of MPONs in the cell and found them to be abundant in the nucleus as early as 24 h after addition with the amount increasing further after 48 and 72 h. The amount of MPONs was 2.5-fold higher than that of unmodified oligonucleotides in the nucleus after 72 h. We also designed antisense oligonucleotides and evaluated the effect of MPONs on mRNA exon skipping using DMD model cells; MPONs caused exon skipping with 69 % efficiency after 72 h, which was three times higher than the rate of the control. In summary, the high capacity for intracytoplasmic and nuclear translocation of MPONs is expected to be useful for therapeutic strategies targeting exon skipping.     

COMPARISON OF PAHS,NITRO-PAHS AND OXY-PAHS ASSOCIATED WITH AIRBORNE PARTICULATE MATTER AT ROADSIDE AND URBAN BACKGROUND SITES IN DOWNTOWN TOKYO,JAPAN

Atmospheric polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and oxy-PAHs are emitted from primary sources. Some nitro-PAHs and oxy-PAHs can also arise from secondary formation in the atmosphere. To assess the relative importance of these sources, the polycyclic aromatic compound (PAC) concentrations were determined at a roadside (Roadside site) and on a rooftop (Urban Background site) in downtown Tokyo Japan. The concentrations of PAHs, 1-nitropyrene and oxy-PAHs at the Roadside site were higher than those at the Urban Background site, while 2-nitrofluoranthene levels were the same at both sites. However, the mean ratios of concentrations at the Urban Background site to the Roadside site were in the order 1,8-naphthalic anhydride>9,10-anthraquinone>PAHs or 1-nitropyrene or acenaphthenequinone or benzanthrone. This suggests that in addition to vehicle emissions, a considerable fraction of some of the oxy-PAHs studied originates from another source, which might be secondary formation by atmospheric PAH degradation, and this contribution varied among the oxy-PAHs.     

Structure, morphology and magnetic properties of Fe-B-Si-Nb glassy alloy thin film prepared by a pulsed laser deposition method

With the aim of applying to a soft magnetic underlayer of the double-layered perpendicular magnetic recording media, an Fe_74.9B_17.5Si_2.5Nb_5.1 alloy thin film was fabricated on Si substrate by a pulsed laser deposition method. The Fe-based alloy thin film of 200 nm in thickness was confirmed as a glassy structure. The thermal properties of the thin film have similar features to those for the melt-spun glassy alloy ribbon. The glassy alloy thin film exhibits good soft magnetic properties, i.e., high B_s of 1.2 T and in-plane low H_c of 134 A/m. The Fe-B-Si-Nb glassy alloy thin film is expected to be suitable for the soft magnetic underlayer material in the double-layered perpendicular magnetic recording media.     

In situ hydrogen plasma treatment for improved transport of (4 0 0) oriented polycrystalline silicon films

Polycrystalline silicon (poly-Si) films were deposited on glass by very high-frequency (100 MHz) plasma enhanced chemical vapor deposition from a gaseous mixture of SiF₄ and H₂ with small amounts of SiH₄. (2 2 0) oriented films prepared at small SiF₄/H₂ ratios (<30/40 sccm) showed intrinsic transport properties of poly-Si. However, the room temperature dark conductivity (σ_d) of the (4 0 0) oriented film was very high for intrinsic poly-Si, 7.2×10⁻⁴S/cm. This conductivity exhibited a T^−1/4 behavior, suggesting a high defect density at the grain boundaries. It was found that in situ hydrogen plasma treatment successfully produced (4 0 0) oriented poly-Si with a reasonably low σ_d of 4.5×10⁻⁷S/cm and a good photoconductivity of 1.3×10⁻⁴S/cm.     

Production technology for amorphous silicon-based flexible solar cells

We have developed a-Si-based solar cells with plastic film substrate and achieved a stabilized efficiency of 9% in a 40 cm×80 cm cell. The structure and fabrication process of flexible solar cells are presented. Then we discuss the merits and demerits of our process from the viewpoint of mass production, and clarify that the SCAF cell has a good adaptability to mass production.     

Investigation of shrinkage behavior of Ni-Fe bimetallic anode tube support and the densification of electrolyte using co-sintering temperature

NiO-Fe₂O₃/gadolinium-doped CeO₂ (GDC), NiO-Fe₂O₃/yttria-stabilized ZrO₂ (YSZ) anode supported fuel cells were fabricated at co-sintering temperatures of anode-electrolyte from 1250 °C to 1400 °C. The volumetric shrinkage of the anode-electrolytes and the porosity of the anode tube were studied systematically at different temperatures. 1300 °C is the marginal temperature to obtain sufficient electrocatalytic activity of electrodes, and a higher temperature is needed to suppress gas leakage through the scandia-stabilized zirconia (ScSZ) electrolyte. At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO-Fe₂O₃/GDC anode tubes is nearly 10% higher than that of NiO-Fe₂O₃/YSZ anode tubes. SEM results exhibited the anode-supported electrolyte tends to be more dense as co-sintering temperature increasing to 1400 °C from 1250 °C. However, the high co-sintering temperature of 1400 °C will result in low porosity of anode which negatively affected the power density.     

A 4.4 ns CMOS 54×54-b multiplier using pass-transistormultiplexer

A 54×54-b multiplier using pass-transistor multiplexers has been fabricated by 0.25 μm CMOS technology. To enhance the speed performance, a new 4-2 compressor and a carry lookahead adder (CLA), both featuring pass-transistor multiplexers, have been developed. The new circuits have a speed advantage over conventional CMOS circuits because the number of critical-path gate stages is minimized due to the high logic functionality of pass-transistor multiplexers. The active size of the 54×54-b multiplier is 3.77×3.41 mm. The multiplication time is 4.4 ns at a 3.5-V power supply     

Oxidation-Induced Microstructural Change of Si-Ti-C-O Fibers

Two types of Si-Ti-C-O fibers STC(6HS) and STC(6H), with different C/Si molar ratios of 0.99 and 1.65, respectively, have been subjected to oxidation tests at high temperatures between 1000° and 1500°C. Both fibers showed different mass gain during the oxidation tests. In the unoxidized region, there was no change in the chemical composition. For STC(6HS), coarse ß-SiC grains were formed throughout the region, while the grain coarsening in STC(6H) was restricted to the vicinity of the film/fiber interface. In this paper, the influence of free carbon on the oxidation-induced microstructural change of Si-Ti-C-O fibers is discussed.     

Enhancement of arachidonic acid production by Mortierella alpina 1S-4

The effect of mineral addition on arachidonic acid (AA) production by Mortierella alpina 1S-4 was evaluated. At first, the addition of minerals such as sodium, potassium, calcium, and magnesium was examined in flask cultures, and then the addition of phosphorus with the optimal amounts of the minerals was investigated in a 10-L jar-fermenter. As a result, 1.5% soy flour medium with the addition of 0.3% KH₂PO₄, 0.1% Na₂SO₄, 0.05% CaCl₂·2H₂O, and 0.05% MgCl₂·6H₂O was found to enhance the AA yield 1.7-fold over that without mineral addition. When 1% yeast extract with the above mineral mixture was used, the AA yield was enhanced 1.35-fold over that without minerals. We also verified that an increase in the polar lipid content occurred in the case of only KH₂PO₄ addition, and that the above-mentioned increase in the AA yield was due to the minerals themselves, not a pH buffer effect.