The plasma source ion implantation technique was applied to modify the surface of ethylene-vinyl alcohol (EVOH) film using various working gases. The effects of the treated films were observed on the adhesion efficiency and physical properties. The hydrophobic properties of EVOH films were greatly enhanced after tetrafluoromethane-plasma source ion implantation (PSII) treatment. On the other hand, the higher hydrophilic properties of EVOH films increased after oxygen-PSII treatment. The results of X-ray photoelectron spectroscopy showed that the improved hydrophobic or hydrophilic properties of the film were closely related to the formation of fluorine-containing functional groups (i.e., CF, CF 2 , and CF 3 ) or oxygen-containing functional groups (i.e., CAO, C¼ ¼O) on the modified surface. According to the result observed by atomic force microscopy, the surface roughness was not influenced on the change of contact angle. Both the peel strength and oxygen barrier property were improved in the case of CF 4 þO 2 -PSII-treated EVOH films. As a function of aging time, the properties of modified EVOH surfaces were maintained after PSII treatment using CF 4 and O 2 at the energy level of À5 kV for 1 min. When using PSII treatment, the properties of the EVOH surface were controlled by working gas and treatment conditions. V V C

The yeast three-hybrid system (Y3H), a powerful method for identifying RNA-binding proteins, still suffers from many false positives, due mostly to RNA-independent interactions. In this study, we attempted to efficiently identify false positives by introducing a tetracycline operator (tetO) motif into the RPR1 promoter of an RNA hybrid expression vector. We successfully developed a tight tetracycline-regulatable RPR1 promoter variant containing a single tetO motif between the transcription start site and the A-box sequence of the RPR1 promoter. Expression from this tetracycline-regulatable RPR1 promoter in the presence of tetracycline-response transcription activator (tTA) was positively controlled by doxycycline (Dox), a derivative of tetracycline. This on-off control runs opposite to the general knowledge that Dox negatively regulates tTA. This positively controlled RPR1 promoter system can therefore efficiently eliminate RNA-independent false positives commonly observed in the Y3H system by directly monitoring RNA hybrid expression. [BMB reports 2010; 43(2): 110-114]

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In this study, total bacteria, enteric members of the -proteobacteria, and microbial communities in seawater were analyzed as indirect indicators for quantifying biofouling. Biomass in seawater can significantly affect feed water pretreatment and membrane biofouling of reverse osmosis desalination processes. The purpose of this paper is to investigate microbiological quantity and quality of seawater at the potential intake of a desalination plant. For this analysis, the total direct cell count (TDC) using 4'-6-diamidino-2-phenylindole (DAPI)-staining and DNA-based real-time PCR were used to quantify the total bacteria and relative content of enteric members of -proteobacteria in seawater, respectively. In addition, microbial communities were examined using 16S rRNA gene cloning and bacterial isolation to identify the most abundant bacteria for a further biofouling study. The experimental results of this study identified about 10 6 cells/mL of (total) bacteria, 10 5 16S rRNA gene copies/mL of enteric -proteobacteria, and the presence of more than 20 groups of bacteria.