Hydrolysed collagen from Lates calcarifer skin: its acute toxicity and impact on cell proliferation and collagen production of fibroblasts

Acute toxicity in Wistar rat and the impact of hydrolysed collagen (HC) from seabass skin on in vitro cell proliferation and collagen production were studied using L929 fibroblasts. HC was rich in glycine (326 residue/1000 residue) and imino acids (196 residue/1000 residue). MALDI mass spectrum of HC showed several low MW peptides with MW range of 1050–1330 Da as the major components. Based on acute oral cytotoxicity test in Wistar rat, HC was considered as safe with LD₅₀ value higher than 5000 mg kg^?1 body. HC could promote L929 cell growth, especially when used in combination with vitamin C (VitC) at a ratio of 2:1. HC/VitC (2:1) mixture also exhibited the higher enhancement effect on collagen production of L929 cells, compared with HC or VitC alone. Thus, HC could be a promising candidate for biological applications, especially in combination with VitC, as nutraceuticals for skin care.     

Fabrication of Y2O3-doped BaZrO3 thin films by electrostatic spray deposition

Electrostatic spray deposition (ESD) technique was used to fabricate dense Y₂O₃-doped BaZrO₃ (BYZ) thin films, which have been extensively studied for the protonic ceramic fuel cell electrolyte. Effects of the ESD process parameters (i.e. substrate temperature, type of precursor, flow rate and applied voltage) on the microstructure of as-deposited films were studied. The uniform as-deposited films were obtained using a mixture of zirconium acetylacetonate, barium chloride dihydrate and yttrium chloride hexahydrate precursors in a solvent mixture of butyl carbitol and deionized water at a volume ratio of 50:50. The optimum deposition parameters were obtained at the substrate temperature of 250 °C with the applied voltage and flow rate in a range of 10-12 kV and 1.4-2.8 ml/h, respectively. The as-deposited films were subsequently annealed at 1350 °C for 10 h to ensure the complete chemical reactions of the precursors. X-ray diffraction patterns reveal the perovskite structures of the annealed BYZ films (deposited on yttria stabilized zirconia substrates) with only traces of Y₂O₃ phase, which could arise from the loss of BaO at high annealing temperatures.     

Irradiation of highly oriented polyethylene fibers in the atmosphere of some vinyl monomers: Effect on compressive strength

Highly oriented polyethylene fibers have been modified by γ‐irradiation in the presence of some vinyl monomer vapors, followed with further annealing in the atmosphere of the same monomer. Two types of vinyl monomers that are known to produce polymers with different glass transition temperatures, namely methyl methacrylate and vinyl acetate, were studied for their effect on the compressive strength of the fiber. It was found that a significant improvement in compressive strength, measured by tensile recoil test, was obtained. The level of improvement was affected by heat treatment and the presence of monomer during irradiation. Modification with vinyl acetate was found to be more effective than methyl methacrylate. These facts suggest that the improvement in compressive strength was attributable to several factors, including structural relaxation, the presence of graft copolymer, and energy dissipation ability of the graft copolymer. It is speculated that lateral integrity of the fiber is one of the key factors that prevents sliding of microfibril and possibly lateral or circumferential expansion of the fiber to accommodate kink band. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2494–2502, 2001     

Cloning, Expression, and Characterization of Thermotolerant Manganese Superoxide Dismutase from Bacillus sp. MHS47

A superoxide dismutase gene from thermotolerant Bacillus sp. MHS47 (MnSOD47) was cloned, sequenced, and expressed. The gene has an open reading frame of 612 bp, corresponding to 203 deduced amino acids, with high homology to the amino acid sequences of B. thuringiensis (accession no. EEN01322), B. anthracis (accession no. NP_846724), B. cereus (accession no. ZP_04187911), B. weihenstephanensis (accession no. YP_001646918), and B. pseudomycoides. The conserved manganese-binding sites (H28, H83, D165, and H169) show that MnSOD47 has the specific characteristics of the manganese superoxide dismutase (MnSOD) enzymes. MnSOD47 expressed an enzyme with a molecular weight of approximately 22.65 kDa and a specific activity of 3537.75 U/mg. The enzyme is active in the pH range 7-8.5, with an optimum pH of 7.5, and at temperatures in the range 30-45 °C, with an optimum temperature of 37 °C. Tests of inhibitors and metal ions indicated that the enzyme activity is inhibited by sodium azide, but not by hydrogen peroxide or potassium cyanide. These data should benefit future studies of MnSODs in other microorganisms and the biotechnological production of MnSOD47, and could also be used to develop a biosensor for the detection of antioxidants and free radical activity. In the future, this basic knowledge could be applicable to the detection of cancer risks in humans and therapeutic treatments.     

Photocatalytic activity of TiO2 coated porous silica beads on degradation of cumene hydroperoxide

Recently, due to an increasing global concern on environmental safety, titanium dioxide (TiO₂) photocatalyst has been extensively researched for use as air and water pollution treatments. This study was initiative for producing an economically viable TiO₂ photocatalyst material with recyclability for degradation of CHP contaminated wastewater. TiO₂ P‐25, a well‐known photocatalyst, with a proper amount (15% w/w of CAC) was coated on porous silica beads (ECOLITE^®) by granulation technique, using high calcium aluminate cement (CAC) as a binder (EC+CAC+15% w/w TiO₂ P‐25). The experiments revealed that high concentration CHP solutions were completely degraded by EC+CAC+15% w/w TiO₂ P‐25 within 5 and 7 hours. The recyclability of EC+CAC+15% w/w TiO₂ P‐25 was evaluated by investigation the degradation activity of freshly prepared CHP solution under UV light irradiation using the repetitive photocatalyst beads for 6 runs. HPLC analyses indicated that the CHP degradation was completed in the 1^st run and down to over 90% in the 6^th run. Hence, EC+CAC+15% w/w TiO₂ P‐25 showed a long durability and good recyclability for CHP degradation, resulted from the good adherence of hydration product layer of CAC for TiO₂ particles as well as its large surface area that offered good adsorption for CHP.     

Comparison of Antioxidant Activity of Grape Seed Extract and Fruits Containing High β-Carotene,Vitamin C,and E

Antioxidant activity of a potent antioxidant, grape seed extract, and fruits containing high β-carotene, vitamin C, and vitamin E was measured and compared by 2,2-diphengl-1-picrylhydrazyl radical and ferric reducing antioxidant power assay. The results showed that antioxidant activity of a 20-mg capsule of grape seed extract was approximately 10 to 20 times greater than 1 g of tomato, papaya, banana, and mango. However, if antioxidant activity was calculated per fruit or piece of fruit, the values were comparable. Therefore, consumption of fruit could be a cost-effective way of healthy eating when the price of a dietary supplement is relatively high.     

Production and shelf stability of multiple-fortified quick-cooking rice as a complementary food

Rice-based complementary foods normally contain inadequate amounts of several micronutrients, such as iron, calcium, and zinc. This study aimed at improving the quality of commercially produced rice-based complementary foods. The analysis centered on identifying a rice-based complementary food that is safe, stable, sensory acceptable, and economical in terms of fortificants (iron, calcium, zinc, thiamine, folate) and effectively packaged for industrial production and distribution. Product colors were mostly in green-yellow tone and slightly changed to more yellow during storage. Sensory acceptability was affected by changes in odor and rancidity but not in color. Rancidity scores were low in aluminum foil laminated plastic bags (ALU). Lipid oxidation significantly increased during storage, but at a slower rate when sodium citrate and ALU were used. Color differences of raw products were detected but not in the cooked ones. Mineral and vitamin losses during processing were 2% to 11% and 20% to 30%, respectively, but no losses were found during storage. FeSO(4)+ NaFeEDTA added with sodium citrate resulted in the most acceptable product for all packagings. The multiple-fortified quick-cooking rice (MFQCR) developed from this study could be a potentially useful tool for combating micronutrient deficiencies among infants and young children in the countries where rice is the staple food.