Production of ultrafine atmospheric pressure plasma jet with nano-capillary

The atmospheric pressure plasma jet (APPJ) has been developed to apply to the ultrafine process for future material processing. In this study, we tried to reduce the diameter of APPJs by using micro- or nano-capillary tubes. To measure the existence of the bullet-like charged particles from the capillary tip, the plasma flow generated from capillary tubes with a diameter of about 100 nm to 5 μm were analyzed by the electrostatic probe. The average propagation velocities of the plasmas flow were estimated from the time differences between the probe signal and spiky discharge current signal. The results show that the velocity of plasma jet delivered from 1 μm ? capillary gradually decreased from 11 to 2 km/s due to a collisional drag force with air with an increase of the distance from capillary tips. From the analysis of etching pattern of resist film by the APPJ with a 500 nm diameter capillary, it was confirmed that the depth and width of the treated trench on the resist film were roughly 30 - 50 nm and 500 - 700 nm, respectively.     

Polypyrrole-supported graphite felt for Heck reaction in solid phase synthesis

Substrate immobilization on graphite felt for solid phase Heck reaction was achieved by electrochemical polymerization of the substrate precursor containing a pyrrole side chain, where the amount of substrate on the electrode surface was easily controlled by the number of repeated cyclic voltammetric scanning. Couplings between olefins and the 4-iodobenzoic acid-modified graphite felt electrode or aromatic halides and the 4-vinylbenzoic acid-modified graphite felt electrode in the presence of palladium catalyst proceeded smoothly in satisfactory yields. The used substrate-modified electrode was reproduced by the treatment of used electrode with activated ester species of 4-vinylbenzoic acid, and was able to be recycled to Heck reaction in solid phase synthesis.     

Proteolytic degradation of myofibrillar components by carp cathepsin L

Carp cathepsin L, which is the best candidate to produce textural change in the arai-treated carp fillet, exhibited maximum hydrolytic activity for Z-Phe-Arg-MCA and soluble casein at pH 5·0–5·5. The proteolytic action of the enzyme was evaluated by complete degradation of various carp myofibrils at pH 5·0 over 30 min and by potent degradation of the same proteins at pH 5·5–6·0 over 20 h. All myofibrillar components were partially degraded by the enzyme at pH 6·5–7·0, but varying amounts of them remained undegraded after 20 h. These findings indicate that carp cathepsin L degrades not only carp myofibrillar components but also their resultant products between pH 5·0 and 7·0 and that it markedly acts on myosin heavy chain, α-actinin and troponin-T and -I. Carp cathepsin L likely contributes to postmortem muscle tenderisation of carp fillet over an extensive pH range during storage. © 1998 SCI.     

Nineteen multiple primary cancer cases of 100 patients undergoing lung cancer resection

In our department, half of 100 consecutive lung cancer resection cases were over the age of 70 years. In the same 100 patients, nineteen cases had multiple primary cancers. Sixteen cases had double, two cases had triple, one case had quadruple primary cancers. The incidence rate of multiple primary cancers involving the lung was 19%. This incidence of 19% is higher than the others ever reported in Japan. It was concluded, when lung cancer patients were elder, that there was increasment in the frequency of multiple cancer cases involving lung, and there was a high possibility of the occurrence of 2nd and 3rd primary cancers.     

Effect of fine sediment deposition and channel works on periphyton biomass in the Makomanai River,northern Japan

The Makomanai River in northern Japan has suffered considerable fine sediment deposition, especially in a reach where channel works have been constructed. Four contiguous reaches were examined for deposition of fine sediment and the effects of such on periphyton biomass; two of the reaches had channel works and bank protection, respectively, the other two being unmodified. The influence of fine sedimentation on epilithic periphyton biomass (chlorophyll a weight and organic matter weight) and the autotrophic index (AI), and the relationship between these and hydraulic variables was emphasized. Fine sediment increased, chlorophyll a decreased and AI increased in the reach with channel works and in the unmodified reach immediately upstream. In addition, the current velocity and Froude number tended to decrease in the reach with channel works. Correlation analysis showed that with an increase in fine sediment, chlorophyll a decreased and non‐living periphyton, indicated by AI, increased. It was also confirmed that fine sediment increased with an increase in weight of periphyton organic matter and decreased with an increase in current velocity or Froude number. These results suggest that accumulation of fine sediment, which substantially reduces light penetration for photosynthesis under low current velocity conditions, results in lowered periphyton levels. The channel works have lowered the current velocity, thus promoting deposition of fine sediment and an increase in non‐living periphyton. Copyright © 2002 John Wiley & Sons, Ltd.     

Structural study of amorphous In2O3 film by grazing incidence X-ray scattering (GIXS) with synchrotron radiation

Grazing incidence X-ray scattering (GIXS) using synchrotron radiation is a very useful method for structural analysis of amorphous films. We investigated the structure of amorphous In₂O₃ film utilizing GIXS at BL19B2 in SPring-8. Radial distribution function (RDF) was obtained from the measurement data. Structural models were constructed by molecular dynamics (MD) and reverse Monte-Carlo (RMC) simulations, and the calculated RDFs from the simulations were compared with that observed. It was found that the average oxygen coordination number around In ions was almost 6 and the average length 2.12 Å, which was smaller by about 3% than that of 2.18 Å in crystalline In₂O₃. It was concluded that the atomic arrangement of the amorphous In₂O₃ was characterized by the increase in the number and the boarder angle of distribution of corner-sharing In-O-In bond compared with crystalline In₂O₃.     

Juvenile masu salmon in a regulated river

We examined the relationship between the physical environment and habitat use of juvenile masu salmon, Oncorhynchus masou, in the Nobori River in Hokkaido, Japan to provide a perspective for the conservation of fish habitat in regulated streams. The study was undertaken during the autumn and winter, with an emphasis on the hierarchy of three spatial scales: microhabitat, channel‐unit and reach scales. The microhabitat‐scale analysis indicated juvenile masu salmon preferred a midstream habitat type, with a greater depth (Avg. ± SD: 35.4 ± 14.2 cm) and high (43.4 ± 23.1 cm s^?1) and uniform current velocities during the autumn, and a channel margin habitat type with a moderate current (about 20 cm s^?1) and submerged cover during winter. In addition, different cover types have different roles in determining juvenile salmon distributions during winter. Grass cover had extremely high carrying capacities, whereas coarse substrate cover provided winter habitat for larger juvenile salmon. Channel‐unit scale analyses showed that abundance of juvenile salmon tended to be higher in pools than runs in the autumn through winter. Reach‐scale analysis showed that abundance and mean body length of juvenile salmon significantly differed between differently regulated reaches during winter, associated with the dominant cover type in each reach. This study demonstrated that the habitat conditions determining juvenile masu salmon distribution differ according to the season and scale of analysis. Therefore, for conservation of fish communities, it is important to evaluate and conserve or create fish habitats in regulated reaches, with a focus on the hierarchy of spatial scales and seasonal differences. Copyright © 2007 John Wiley & Sons, Ltd.     

Hydrogen distribution in titanium materials with low outgassing property

This paper addresses a hydrogen outgassing mechanism in titanium materials with extremely low outgassing property by investigating hydrogen atoms distribution in depth around the surface in a titanium material and stainless steel. The evacuation time dependence of depth profiles of positive hydrogen ions was measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS). In the stainless steel, concentration of hydrogen atoms decreases slowly at the surface oxide layer, while it decreases rapidly in the bulk by vacuum evacuation. Thus, the surface oxide layer is considered to prevent hydrogen diffusions in the bulk. On the other hand, in the titanium material, hydrogen atoms show maximum concentration at the boundary between the surface oxide layer and the bulk titanium. Moreover, concentration of hydrogen atoms decreases rapidly at the surface oxide layer, while those decrease slowly in the deep region below the surface-bulk boundary by vacuum evacuation. It is suggested that the boundary between the surface oxide layer and bulk titanium plays a role of a barrier for bulk hydrogen diffusions. These facts give very low hydrogen concentration near the surface, which results in an extremely low outgassing rate in titanium materials.     

Role of matrix metalloproteinase-7 in angiogenesis associated with age-related macular degeneration

To investigate the possible role of matrix metalloproteinase-7 in choroidal neovascularization associated with age-related macular degeneration, immunoelectron microscopy using ultrathin frozen sections and conventional transmission electron microscopy were performed in subfoveal fibrovascular membranes from patients with age-related macular degeneration. immunoelectron microscopy revealed that matrix metalloproteinase-7 was expressed within basal laminar deposits and amorphous materials around the retinal pigment epithelial cells. The results support a role for matrix metalloproteinase-7 in the development of choroidal neovascularization in age-related macular degeneration.