In this paper we describe a new surface-enhanced Raman scattering (SERS)-active silver substrate that was roughened using a combination of electrochemical triangular-wave oxidation/reduction cycles (ORCs) and argon plasma treatment to obtain a stronger SERS effect. The mechanically polished Ag substrate was first treated with radio-frequency-excited Ar plasma. The treated Ag substrate was then roughened through ORC treatment in an aqueous solution containing 0.1 M KCl. Finally, this roughened Ag substrate was retreated with radio-frequency-excited Ar plasma. Rhodamine 6G (R6G) was used as a Raman probe to evaluate the SERS enhancement of the various Ag substrates. Encouragingly, the SERS intensity of R6G was increased up to 8-fold, with the SERS spectrum of R6G exhibiting better resolution, when using the fully treated Ag substrate, relative to the use of an electrochemically ORC-treated Ag substrate that had not been subjected to plasma treatment. The improved SERS effects were related to the coalescence of grains and hills as well as the formation of dells and pits during the electrochemical ORCs and Ar plasma roughening processes.

These results suggest that overexpression of these two CC chemokine ligands is associated with tumor metastasis and serves as a prognostic factor in patients with gastric cancer.

SYNOPSISGraft copolymerization of 2-hydroxyethyl methacrylate ( HEMA) as attempted onto the surface of silicone rubber membrane, which was pretreated by Ar-plasma, then exposed in oxygen to introduce a peroxide group. The effect of the amount of HEMA grafted on Arplasma-treated and graft copolymerization was examined for various parameters of power, pressure, time, reaction time, and concentration of HEMA aqueous solution. The surfaces were characterized by ATR-FTIR, ESCA, contact angle, and SEM. PHEMA was indicated by ATR-FTIR and ESCA analysis to be present successfully onto the grafted surface of silicone rubber membrane. The stable wettability, as demonstrated once the PHEMA grafted films, indicated contact with a hydrated environment by the study of contact angle. 0 1994

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Our previous microarray analysis of gastric cancer found that claudin-4 was differentially expressed between intestinal-type gastric cancer (IGC) and diffuse-type gastric cancer (DGC). Claudin-4 is a member of a large family of transmembrane proteins, claudins, essential in the formation and maintenance of tight junctions. To explore the roles of claudin-4 in the two histologically distinct types of gastric cancer, we selected 45 IGC and 48 DGC cases and then analyzed the expression of the protein using immunohistochemistry. We found that the overexpression of claudin-4 was greater in IGC than in DGC. A trend was observed between the overexpression of claudin-4 and lymph node metastasis, however, this association was not statistically significant. The results showed that the expression of claudin-4 was lower in DGC. Possibly it played a role in determining the diffuse phenotype and loose cohesion of cells in DGC in a similar manner as E-cadherin.