Bio-information scanning technology using an optical pick-up head

We have developed a low cost and a highly compact bio-chip detection technology by modifying a commercially available optical pick-up head for CD/DVD. The highly parallel and miniaturized hybridization assays are addressed by the fluorescence emitted by the DNA-chip using the optical pick-up head. The gap between the objective lens and the bio-chip is regulated by the focus servo during the detection of the fluorescence signal. High-resolution and high-speed scanning is effectively realized by this simple scanning system instead of utilizing high-precision mechanism. Regardless of achievement of effective detection mechanism, the technique of fluorescence detection can prove to be disadvantageous because of the low stability of the dyes with low S/N ratio and an expensive setup such as a PMT detector is always required for fluorescence detection. We propose, for the first time, a novel scanning scheme based on metal nanoparticles in combination with a bio-chip substrate having a phase change recording layer. We found that the phase change process is highly affected by the existence of the densely condensed metal nanoparticles on the phase change layer during the writing process of the pick-up head.     

Detection of zearalenone and related metabolites by fluorescence polarization immunoassay

Zearalenone is an estrogenic mycotoxin commonly found in grains throughout the world. A number of instrument- and antibody-based methods including enzyme-linked immunosorbent assays (ELISAs) have been developed to detect zearalenone (ZEN) and related toxins in commodities and foods. Although convenient, the commercial ELISAs for small molecules such as ZEN require a washing step to separate bound and unbound enzyme label before detection. In fluorescence polarization immunoassays, separation of bound and unbound label is not required, a property that reduces the time needed to perform the assays. We developed a fluorescence polarization immunoassay for ZEN in maize. When combined with a rapid extraction technique, the assay could be used to detect as little as 0.11 microg of ZEN g(-1) maize within 10 min. The assay showed cross-reactivity to the ZEN analogs zearalanone, alpha-zearalanol, alpha-zearalenol, beta-zearalenol, and beta-zearalanol of 195, 139, 102, 71, and 20%, respectively, relative to ZEN (100%). Recovery of ZEN from spiked maize over the range of 0.5 to 5 microg g(-1) averaged 100.2% (n = 12). The fluorescence polarization immunoassay results were comparable to those obtained with a liquid chromatographic method for the analysis of 60 naturally contaminated maize samples and maize samples amended with culture material. The fluorescence polarization immunoassay provides a rapid method for screening of maize for ZEN.     

Magnesium interlayered diamond coating on silicon

Diamond thin films have been deposited using hot filament chemical vapour deposition technique on manually scratched p-Si(1 0 0) substrate, with and without magnesium interlayer. In spite of magnesium melting point being lower (T_m = 649 °C) than the growth temperature of the substrate (T_s  750 °C) used in these experiments, it was found that high quality diamond films could be grown on Mg covered substrate. A liquid substrate is probably generated during the diamond film growth. Raman spectroscopy analysis exhibited only the triply degenerate, zone centre optical phonon peak at 1333 cm⁻¹ indicating that nearly stress free crystallites were present. Broadening of the Raman peak (11.76 cm⁻¹) indicates that some small crystallites also are present. Scanning electron and atomic force microscopy accompanied by X-ray diffraction analysis where used to compare the details of diamond film growth directly on scratched Si(1 0 0) and Mg interlayered scratched Si(1 0 0) substrates.     

Protective effect of carvacrol from <Emphasis Type="Italic">Thymus quinquecostatus</Emphasis> Celak against <Emphasis Type="Italic">tert</Emphasis>-butyl hydroperoxide-induced oxidative damage in Chang cells

Carvacrol is a monoterpenic phenol present in Thymus quinquecostatus Celak. The protective effects of carvacrol against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage were investigated in human Chang cells. Cells treated with carvacrol extracts promoted Chang cell survival and protection was associated with stabilization of the mitochondrial membrane potential (MMP), prevention of oxidative stress-triggered reactive oxygen species (ROS), and lipid peroxidation (MDA production). In addition, Annexin V/PI, observed using Hoechst staining, indicated that carvacrol inhibited t-BHP-induced cell damage and stimulated the antioxidant capability of Chang cells due to elevation of glutathione (GSH) levels, which were reduced by t-BHP treatment. Carvacrol prevented oxidative stress-induced Chang cell damage via suppression of ROS and MDA levels, and increased GSH levels.     

Antioxidant activity of enzymatic extracts from the brown seaweed Undaria pinnatifida by electron spin resonance spectroscopy

Enzyme assisted extraction of Undaria pinnatifida was performed using five proteases (Alcalase, Flavourzyme, Neutrase, Trypsin and Protamex) and six carbohydrases (AMG, Dextrozyme, Maltogenase, Promozyme, Viscozyme and Celluclast) in order to acquire extracts rich in antioxidants. Antioxidant activity of the extracts was investigated using electron spin resonance (ESR) spectroscopy on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide radicals. Extracts exhibited strong radical scavenging activity on DPPH and hydroxyl radical, and activity increased with increasing extract concentration. In contrast to DPPH and hydroxyl radical scavenging activity, extracts showed weak scavenging activity on superoxide radical. Extracts exhibited weak radical scavenging activity compared to vitamin C as a reference compound. However, they are still a good source of antioxidant materials that are safe for consumption and show water-soluble properties.     

Effect of Cross-linking Agent on Barbituric Acid-initiated Resin

To improve the tensile bond strength of denim bonding agents, the adhesion between denim and MMA resin was investigated by applying initiator systems containing 1-cyclohexyl-5-ethyl barbituric acid (CEB), copper acetyl acetonate (CAA), quaternary ammonium chloride (QAC). cupric ion, with the addition of TEGDMA, and pretreatment solution for denim, and an HEMA primer. The effects of a cross-linking agent on barbituric acid-initiated denim bonding resin were examined by measuring degree of conversion, molecular weight, hardness of bonding resin, and tensile bond strengths.     

Antioxidant and angiotensin I converting enzyme inhibitory activity of Bambusae caulis in Liquamen

Bambusae caulis in Liquamen (BCL) is a nutritious liquid that can be extracted from heat-treated bamboo stems. It is also an important herbal medicine in Asia. In this study, antioxidant and angiotensin I converting enzyme (ACE) inhibitory activity of BCL were investigated. BCL significantly quenched DPPH and peroxyl radicals measured by electron spin resonance (ESR) spectroscopy, while IC₅₀ values were 79.85 and 28.85 μg/ml, respectively. The ability of BCL to inhibit the oxidative damage of DNA was assessed in vitro by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. It was found that BCL significantly protected hydroxyl radical-induced DNA damage in a dose-dependant manner, while also inhibiting apoptosis in hydrogen peroxide-induced PC-12 cells and angiotensin I converting enzyme (ACE) activity. These findings suggest that BCL may be a beneficial ingredient in functional foods and/or pharmaceuticals.