In Situ Visualization of Impacting Phenomena of Plasma-Sprayed Zirconia: From Single Splat to Coating Formation

The authors have developed an in situ monitoring system for particle impacts under atmospheric dc plasma spraying conditions. This system utilized a high-speed video camera coupled with a long-distance microscope, and was capable of capturing the particle-impinging phenomena at one million frames per second. To understand the coating formation mechanism, two approaches were attempted, i.e., observation of the single splat formation and the subsequent coating formation. In the former case, the deformation and cooling processes of yttria-stabilized zirconia (YSZ) droplets impinging on substrates were successfully captured. In the latter case, multiple-droplet-impacting phenomena were observed as an ensemble treatment. Representing the coating process, the tower formation (0-dimensional) and bead formation (1-dimensional) were observed under typical plasma spray conditions for thermal barrier coatings using a triggering system coupled with the motion of a robot. The obtained images clearly showed the coating formation resulting from the integration of single splats.     

Proteins and protein-rich biomass as environmentally friendly adsorbents selective for precious metal ions

Proteins exhibit specific interactions with various metal ions, which play important roles in a living cell. Here, we found that various proteins selectively adsorbed precious metal ions at a wide range of pH values. Studies on protein sequences and on synthesized peptides revealed that a histidine-containing sequence had specific interactions with precious metal ions (Au3+ and Pd2+). We then investigated a few types of protein-rich biomass as adsorbents for precious metal ions. In the presence of various transition metal ions, Au3+ and Pd2+ were also selectively adsorbed onto the biomass tested. The bound precious metal ions were recovered by aqua regia after charring the metal-bound biomass. Finally, we demonstrated the successful recovery of Au3+ and Pd2+ from a metal refining solution and a metal plating waste using the biomass. We propose an environmentally friendly recycling system for precious metal ions using protein-rich biomass.     

Effect of pH on the properties of protonated polyaniline-based films for pH sensing applications

The chemical and physical properties of protonated polyaniline (PANI)-based films, including PANI-emeraldine salt (ES) and PANI/polyvinyl acetate (PVAc) films, before and after pH treatments are characterized and compared. Protonated PANI-based films are prepared by spin coating. The effects of pH value and immersion time on the film properties are investigated to gain a better understanding of their performance in pH sensing. The films are characterized based on color, morphology, chemical structure, phase state, and protonation state. Protonated PANI-based films exhibit a color change from green to dark blue as deprotonation occurs in solutions with higher pH. The highly porous structure of PANI/PVAc films is slightly affected by the pH of the solution. However, the globular structure of the PANI-ES films forms cracks with increasing immersion time. PANI/PVAc films exhibit better stability in acidic and neutral solutions than in alkaline solutions because of the hydrolysis of PVAc. Compared with the negligible differences in the PANI/PVAc film in buffers with different pH, PANI-ES exhibits noticeable changes. Therefore, PVAc improves the stability and performance of PANI for pH-sensing applications.     

Breath hold MR cholangio-pancreatography (MRCP) using long echo train length fast spin echo sequence in combination with surface coil

To test the feasibility of MR cholangio-pancreatography (MRCP) using long echo train length (32) fast spin echo sequence in combination with shoulder surface coil, 20 patients who had had ERCP were examined. Good correlations were acquired between the findings obtained by two modalities in terms of ductal strictures, dilatations and intraductal lesions. MRCP was considered to be an examination of choice in various kinds of pathologies affecting biliary duct as well as pancreatic duct for its non-invasiveness and reasonable image quality.     

Non-Compressed Video Signal Optical Transmission Equipment and Its Applications for Studio to Transmitter Link (STL)

This paper describes the newly developed video signal transmission equipment for Synchronous Optical Network (SONET) and the Synchronous Residual Time Stamp (SRTS) method for video signals. It explains why a low jitter signal transmission is possible by optimizing the SRTS parameters and reducing high frequency jitters by PLL circuit. Moreover, the broadcasting Transport Stream (TS) signal transmission methods for Studio to Transmitter Link (STL) are reviewed and the proposed reference clock transmission method is discussed. The TS signal transmission experiments are carried out using two route trunks between Sapporo and Asahikawa, for evaluating the characteristics of the reference clock, the modulator output signal, and the quality of the received video. The low jitter and error-free video signals transmission is realized in these trunks     

Rubber as additives to lower thermal expansion coefficient of plastics: 1. Morphology and properties

A substantial approach was proposed to design polymer alloys with very low coefficient of linear thermal expansion (CLTE). The large reduction in CLTE is not based on an addition of low-thermal-expansion filler to suppress the bulk expansion, but on the fine control of the polymer alloy's micro-morphology so that the expansion is preferentially toward the thickness direction. In this study, rubber was used as an additive to tune the thermal expansion behavior of various plastics. Although the rubber has a high thermal expansion coefficient, it was found that, when the rubber domains are deformed into microlayers and co-continuous with the plastic matrix, the CLTE of the polymer alloy parallel to the microlayer directions could be reduced to a very low level. Various influencing factors including rubber concentration, viscosity ratio, interfacial adhesion as well as the domain size were investigated.     

Identification of the odour-active aldehyde trans-4,5-epoxy-(E,Z)-2,7-decadienal in yuzu (Citrus junos Sieb. ex Tanaka)

Yuzu (Citrus junos Sieb. ex Tanaka) is a variety of sour citrus fruit that is popular in Japan. In this study, we investigated its aroma, which many people, especially in Japan, find appealing. Aroma extract dilution analysis was used to screen the odour-active compounds in the yuzu volatile oil. An unknown odorant with an albedo-like odour and a high flavour-dilution factor was detected. To identify this odorant, it was separated via flash column chromatography on silica gel and then fractionated by preparative high-performance liquid chromatography on a reverse-phase column. The volatile fraction, which contained a significant amount of the target unknown compound, was analysed by gas chromatography–mass spectrometry and gas chromatography–olfactometry to determine its mass spectrum, retention index, and odour quality. By comparing the resultant data with that of a synthesised authentic reference compound, it was evident that the unknown odorant was trans-4,5-epoxy-(E,Z)-2,7-decadienal (3); this is the first time that it has been identified as an odour-active unsaturated aldehyde in yuzu volatile oil. From the results of a model formation experiment, we propose that trans-4,5-epoxy-(E,Z)-2,7-decadienal originates from α-linolenic acid via 13(S)-hydroperoxy-(Z,E,Z)-9,11,15-octadecatrienoic acid (13(S)-HPOT), which is a lipoxygenase-induced oxidation product of α-linolenic acid.     

Serodiagnosis of chronic hepatitis C in Japan by second-generation recombinant immunoblot assay

The seroprevalence of antibodies to hepatitis C virus (HCV) by a second-generation recombinant immunoblot assay (RIBA-2) was tested using 4 recombinant antigens. The results were correlated with those of C100-3 enzyme-linked immunosorbent assay (ELISA) and with the detection of HCV-RNA sequences by the polymerase chain reaction. Sera were obtained from 27 C100-3 ELISA-positive Japanese patients with chronic non-A, non-B liver disease and from 29 C100-3 ELISA-negative patients. All C100-3 ELISA-positive patients and 19 (66%) out of 29 C100-3 ELISA-negative patients reacted to two or more RIBA-2 antigens (reactive by RIBA-2). Of the remaining 10 C100-3 ELISA-negative patients, one patient reacted to just one antigen (indeterminate by RIBA-2), while 9 reacted to none of the 4 antigens (non-reactive by RIBA-2). Forty-three (93%) of the 46 RIBA-2-reactive patients and the single RIBA-2-indeterminate patient tested positive for HCV-RNA sequences, whereas only one (11%) of the 9 RIBA-2-non-reactive patients tested positive. These findings indicate that HCV infection is more prevalent than expected from the results of C100-3 ELISA, and that RIBA-2 is a more sensitive assay for estimating the presence of HCV infection in chronic liver disease.     

New phospholipase A2 inhibitor: synthesis and inhibition mechanism of oxazolidinone phospholipid analog

(R)-3-Dodecanoyl-4-phosphatidylcholino-hydroxymethyl-2-oxazolidino ne (7), which is a new glycerophospholipid analog, was synthesized starting from (S)-glycidol through a 4-alkylsilyoxymethyl derivative and N-acyl-4-hydroxymethyl derivative. The cyclic amide analog 7 showed strong inhibitory activity toward both Group I and II PLA25, but the inhibitory potency of 7 was slightly weaker than that of the linear amide analog (R)-1, which had been developed by de Haas et al. (Biochem. Biophys. Acta 1990, 1043, 67). The interactions of 7 with human secretory PLA2 was investigated by computer modeling in comparison with those of the linear amide analog 1. The results of the computer modeling were very compatible with those of the inhibitory activities toward PLA2S, and the both results showed that the binding mode of the oxazolidinone analog 7 was very similar to that of the genuine substrate and was different from that of the linear amide analog 1.     

Phospholipids from the free-living nematodeCaenorhabditis elegans

The phospholipid and the fatty chain compositions of diacyl, alkylacyl and alkenylacyl glycerophospholipids of the free-living nematode,Caenorhabditis elegans, were investigated. The phospholipids were comprised of 54.5% ethanolamine glycerophospholipid (EGP), 32.3% choline glycerophospholipid (CGP), 8.1% sphingomyelin and 5.1% others. The most abundant fatty acid in CGP was eicosapentaenoic acid (20∶5n−3). The fatty acids in CGP were more unsaturated than those in EGP. Alkenylacyl and alkylacyl subclasses accounted for 1.0 and 2.6%, respectively, of CGP and 14.0 and 19.6%, respectively, of EGP. At least 80% of the alkenyl and alkyl groups were 18∶0 chains and the remaining were odd numbered chains. The potential presence of platelet-activating factor (PAF) was examined by bioassay, but PAF-like activity was not detected in the extracts of this nematode.