Advanced Materials Research Vols. 690-693

Abstract: The type I collagen was used to prepare self-assembly film, the UV-vis spectrophotometer and Fluorescence spectrophotometer were employed to characterize those self-assembly films. The Fe (NO₃)₃ and CuSO₄ were used as the additive to investigate the effect of the type I collagen film. It was found that the character spectra of collagen solution and self-assembly film were different, the Fe (NO₃)₃ enhanced the 408nm fluorescence emission peak, and CuSO₄ caused a new emission peak at 399nm. The changes in the fluorescence of films suggest that the metal salt could affect the type I collagen self-assembly.

Abstract: The tautomerization reaction mechanisms between three stable 6-thioguanine tautomers were investigated theoretically using B3LYP/6-311+G(d,p) method. The results show that the pathway P(1) is to isomerize from TG(9,10,10,11) to TG(1,9,10,10) and the needed activation Gibbs free energy barrier is 112.7 kJ/mol with the rate constant of 1.12×10^-7 s^-1. Another two pathways P(2) and P(3) are to isomerize from TG(1,9,10,10) to TG(1,7,10,10) and the activation Gibbs free energy barriers of the rate-determining steps are 227.4 and 281.6 kJ/mol, respectively, with the related rate constants of 8.96×10^-28 s^-1 and 2.86×10^-37 s^-1, these results implying the intramolecular proton transfer reactions are infeasible in the gas phase.

Abstract: The incidence and mortality of skin cancer continue to rise because of the destruction of the ozonosphere in the earth. Skin cancer is divided into two groups by histological features – nonmelanoma skin cancers (NMSC) and melanoma. Cutaneous basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of NMSC are almost 75% among human skin malignancy cancer. In the preliminary bioactivity screening, the compound isolated from Helminthostachys zeylanica were evaluated antioxidant activities and interacted individually with serial human cancer cells, results that antioxidant activities of ugonin K were evaluated by measuring DPPH free-radical scavenging activities, and reducing power. Determination the reactive oxygen species (ROS) content and reduced glutathione (GSH) formation in H₂O₂-treated HaCaT cells by ugonin K. The cytotoxicity results show that ugonin K expressed less toxic to human keratinocytes (HaCaT cells) and human skin fibroblasts (Hs68 cells) than BCC cells, suggesting that ugonin K may have potential to be developed effective drugs for skin cancer cells without damaging skin normal cells. After treatment with ugonin K in BCC cells, cell cycle arrested in S-G₂/M phase with a markedly increased apoptotic sub-G₁ peak, mitochondria membrane potential (MMP) reduced, the expression of p53, Caspase-8, Caspase-9 and Caspase-3 revealed a more significant increased than the untreated control. Expected ugonin K has potential for an effective and specific drug to cancer cell, can minimize the damage to normal cell and provide a better therapeutic method to skin carcinoma.

Abstract: Recovery and use of secondary fiber for paper production is increasing all over the word. In recovered paper recycling, stickies are the most detrimental among the contaminants, affecting both the process efficiency and the quality of the final product. In this study, StickAway enzyme was used to treat the old newspaper(ONP) pulps. The effect of enzymatic treatment on the macro and micro-stickies, the drainage property, as well as the formation of paper products were investigated. After treatment of samples with 3LU/g (o.d pulp) doses of enzymatic for 1.5 h, it was found that 14.6% of the micro-stickies could be removed. The cationic demand, turbidity value and particle size were decreased 7.23%, 14.4% and 6.02% respectively compared the control sample. Furthermore, enzymatic treatment also improved the drainage properties of pulp slurry and the formation of paper products. Results confirmed that under the optimal conditions, the StickAway enzyme show the excellent performance in the treatment of the stickies of recovered pulps.

Abstract: Microalgae, in wet conditions, tend to grow on surfaces and form biofilms. The adhesion of microalgae to surfaces is very important for algal mass culture. The formation and development of microalgal biofims are in large denpend on the properties of cell surface, substratum surface and gowth medium. In this paper, the influence of substratum surface zeta potential on the microalgal biofilms was particularly investigated. We focused on a widely-used microalgal strain, the freshwater autotrophic Chlorella sp..The adhesion phenomena of Chlorella sp. to surfaces with different zeta potential were observed microscopically. It was found that Chlorella sp. adhered easily to the surface with a positive zeta potential and difficultly to the surface with a negative zeta potential. We concluded that the surface zeta potential had a greater influence on the adhesion of microalgal cells to substratum surfaces. Our findings have important implications for microalgae mass culture and harvesting.

Abstract: in this work, the organic macromolecules adsorbent cyanoethylated carboxymethyl cellulose having hydrophilic and lipophilicity characteristics were preparated through properly carboxymethylation and cyanoethylation process, basing on cotton stalk cellulose treated by steam explosion as raw material, which the content of cellulose in the product is 72.6%. The effect of carboxymethylation degree on cyanoethylation degree was discussed. Then its characteristics of solubility, thermal properties, acid resistance and absorptive property were researched

Abstract: The article describes the non conventional coke utilisation possibilities and production from alternative sources and lower quality non renewable resources. A lot of the so-called pyrolytic carbon semi-coke is created within operations of pyrolytic units. The research objective is to find a suitable methodology for the preparation and treatment of semi-coke for its consequent industrial utilisation. Also, it is good to consider the use of this raw material as an alternative fuel, or its combustion in mixtures.

Abstract: The electrochemically mediated delignification of pulp fibers is one of the promising bleaching methods, which can give the delignified pulp with good subsequent bleachability and high pulp viscosity. Our previous work has shown that the poplar kraft pulp can be delignified to 45% delignification ratio with less than 10% pulp viscosity loss at the condition of 1% pulp consistency which limits the application of this method in pulp industry. The high-consistency electrochemical delignification of poplar kraft pulp was investigated in this paper. The delignification ratio, pulp viscosity loss and brightness were measured as well as the delignification conditions, such as pulp consistency, voltage of electrolysis cell, temperature, circulation of electrolysis liquor and time, were discussed. The results showed that at the 10% pulp consistency, the circulation of electrolysis liquor between pulp cell and electrolysis cell can efficiently improve the delignification ratio, and the pulp viscosity loss is less than 10%. The subsequent bleachability for H₂O₂ is similar as that of 1% consistency delignified pulp. The pulp also can be bleached to higher than 80% ISO with following EP stage at 2.5% H₂O₂ dosage.

Abstract: Gold immunochromatography assay (GICA) technique has the following characteristics: rapid and simple, high sensitivity, good specificity, no auxiliary equipment, ease of interpreting results, and satisfactory stability. The technique has become one of the most rapid and sensitive immunological detection methods, which is widely used in medical, biological and other fields. The article focuses on the basic principles and technical characteristics of GICA, and briefly describes the applications and future perspectives in the rapid detection of aquatic products.

Abstract: Sodium hydroxide (NaOH) substituted by magnesium hydroxide (Mg(OH)2) as control agent and alkali source were investigated in chlorine dioxide bleaching and hydrogen peroxide bleaching of NaOH-AQ wheat straw pulp. The effects of alkali sources on pulp properties, including brightness and tensile strength, were investigated. The four experimental groups, including DNaOHPNaOH, DNaOHPMg(OH)2, D Mg(OH)2PNaOH and DMg(OH)2PMg(OH)2, were studied in this paper. The results showed that the brightness and tensile strength of DMg(OH)2PMg(OH)2 pulp was slightly lower than that of DNaOHPNaOH pulp. But there were more residual ClO2 and residual H2O2 in the effluents of DMg(OH)2PMg(OH)2 bleaching process than that in the effluents of DNaOHPNaOH bleaching process, which illustrated that DMg(OH)2PMg(OH)2 bleaching process had higher bleaching efficiency than DNaOHPNaOH bleaching process. The influence of Mg(OH)2 replacing NaOH was more obvious when it was used in the bleaching process of P stage than that in the D stage. The replacement of NaOH with Mg(OH)2 in D Stage can lower the dosage of alkali used in the following P stage.