The thermal deactivation of engine-aged Pd/CeO2–ZrO2 three-way catalysts was studied by chassis-dynamometer driving test cycles with cold start and in situ diffuse reflectance spectroscopy (DRS). The extent of the catalyst deactivation after engine-aging at 800–1000 °C was correlated with the microstructural evolution, which was analyzed by X-ray diffraction, X-ray absorption spectroscopy, electron microscopy, and a chemisorption technique. This suggests that deactivation is caused by degradation of the catalytically active sites in the three-phase boundary (TPB) region, where Pd, CeO2–ZrO2, and the gas phase meet. The time-resolved in situ DRS revealed that the reoxidation of Pd metal under fluctuating air-to-fuel ratios was retarded relative to the reduction of Pd oxide. The retardation is attributable to the oxygen storage in CeO2–ZrO2. In the fresh catalyst with a high dispersion, most Pd was close to the TPB. Conversely, after engine-aging at elevated temperatures, the retardation effect was less pronounced with respect to Pd particle growth. Grown into large Pd particles, the Pd at sufficient distances from the TPB was no longer affected by the oxygen storage. Consequently, from the ratios of the initial rate constants of the Pd oxidation and reduction under fluctuating air-to-fuel ratio conditions, we can understand the quality and/or quantity of the TPB site in engine-aged catalysts. This measure provides a useful index of the extent of catalyst deactivation.
To estimate the contribution of uncultured bacterial groups to fiber degradation, we attempted to retrieve both ecological and functional information on uncultured groups in the rumen. Among previously reported uncultured bacteria, fiber-associated groups U2 and U3, belonging to the low-GC Gram-positive bacterial group, were targeted. PCR primers and fluorescence in situ hybridization (FISH) probe targeting 16S rRNA genes or rRNA were designed and used to monitor the distribution of targets. The population size of group U2 in the rumen was as high as 1.87%, while that of group U3 was only 0.03%. Strong fluorescence signals were observed from group U2 cells attached to plant fibers in the rumen. These findings indicate the ecological significance of group U2 in the rumen. We succeeded in enriching group U2 using rumen-incubated rice straw as the inoculum followed by incubation in an appropriate medium with an agent inhibitory for Gram-negative bacteria. Consequently, we successfully isolated two strains, designated B76 and R-25, belonging to group U2. Both strains were Gram-positive short rods or cocci that were 0.5 to 0.8 m in size. Strain B76 possessed xylanase and ␣-L-arabinofuranosidase activity. In particular, the xylanase activity of strain B76 was higher than that of xylanolytic Butyrivibrio fibrisolvens H17c grown on cellobiose. Strain R-25 showed an ␣-L-arabinofuranosidase activity higher than that of strain B76. These results suggest that strains B76 and R-25 contribute to hemicellulose degradation in the rumen.
New flexible fibrous glass-reinforced plastic (FRP) substrates for flat panel displays were developed. Optimizing the composition of the FRP by adjusting the difference in refractive index between a matrix resin and a glass fiber enabled the coexistence of a high transparency and a low coefficient of thermal expansion (CTE). An excellent smooth surface morphology was confirmed by the formulation of a coating resin. The stability of moisture impermeability depended on the surface smoothness and adhesion between a barrier layer and the coating layer. The moisture permeation rates of barrier substrates were below detection limits (<0:01 g m À2 day À1 ) on standard measurement equipment.
Inherited skin disorders have been reported recently to have sporadic normal-looking areas, where a portion of the keratinocytes have recovered from causative gene mutations (revertant mosaicism). We observed a case of recessive dystrophic epidermolysis bullosa treated with cultured epidermal autografts (CEAs), whose CEAgrafted site remained epithelized for 16 years. We proved that the CEA product and the grafted area included cells with revertant mosaicism. Based on these findings, we conducted an investigator-initiated clinical trial of CEAs from clinically revertant skin for recessive dystrophic epidermolysis bullosa. The donor sites were analyzed by genetic analysis, immunofluorescence, electron microscopy, and quantification of the reverted mRNA with deep sequencing. The primary endpoint was the ulcer epithelization rate per patient at 4 weeks after the last CEA application. Three patients with recessive dystrophic epidermolysis bullosa with 8 ulcers were enrolled, and the epithelization rate for each patient at the primary endpoint was 87.7%, 100%, and 57.0%, respectively. The clinical effects were found to persist for at least 76 weeks after CEA transplantation. One of the three patients had apparent revertant mosaicism in the donor skin and in the post-transplanted area. CEAs from clinically normal skin are a potentially well-tolerated treatment for recessive dystrophic epidermolysis bullosa.
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