Advanced Materials Research Vols. 236-238

Abstract: Conclusion:A good short-term hearing improvement is gained by partial ossicular replacement prostheses with several common various materials.A better sound transmission in lower frequencies is obtained by partial ossicular replacement prostheses with hydroxyapatite ceramics, stainless steel and alumina ceramics.However,A better sound transmission in higher frequencies is gained by partial ossicular replacement prostheses with porous polyethylene and polytetrafluoroethylene.Considering a long-term effect on hearing improvement,they are better materials on hearing restoration because titanium, polytetrafluoroethylene and hydroxyapatite ceramics have a good biocompatibility for the patients.And these conclusions can provide certain reference values for human ear clinical studies.Objectives:This paper qualitatively and quantitatively studied the effect of partial ossicular replacement prostheses (PORPs) with several various materials on hearing restoration.Methods:The CT data of the right ear from a normal human body was digitalized and imported into PATRAN to establish a three dimension finite element mode1by self-compiling program,and then a frequency response analysis was made for the model using NASTRAN to study the effect of partial ossicular replacement prostheses with several various materials on hearing restoration.Results:the model was carried through a harmonic response analysis of normal ear structure and confirmed by the consistency in the calculated and experimental data after comparision.

Abstract: Based on the idiographic character of collagenous domain of human type III collagen, a recombinant human gelatin monomeric gene (gel) was designed and synthesized. All hydrophobic amino acids (proline excluded) were replaced by hydrophilic amino acids to improve the hydrophilic properties, and the codons encoding amino acids were optimized according to Pichia pastoris bias usage. Then a recombinant human gelatin expression vector pPIC9KG6 containing six monomeric genes ligated in the same orientation was constructed successfully. After verificated the validity of construction by DNA sequencing, the recombinant vector pPIC9KG6 was electroporated into the Pichia pastoris GS115, and Mut⁺ pPIC9KG6 transformants were selected on the basis of G418 resistance. Then a high-level expression strain was picked up from transformants by analyzing their recombinant protein expression levels. SDS-PAGE analysis of cell lysate and fermentation supernatant of the high-level expression strain showed that recombinant human gelatin can be expressed intracellularly and secreted expression, and its expression level reaches 16.06 g per liter. Secreted recombinant human gelatin was purified from fermentation supernatant by gel filtration chromatography. By UV spectroscopy and FTIR and SEM, it was confirmed that purified recombinant human gelatin is similar to animal-derived gelatin in protein structure.

Abstract: This investigation shows that ozagrel, an antithrombotic drug, can inhibit mushroom tyrosinase well. The IC₅₀ value was 3.45 mmol/L. Ozagrel was estimated to be a reversible mixed-type inhibitor of mushroom tyrosinase by Lineweaver-Burk plots. The inhibition kinetics has been studied by using the kinetic method of the substrate reaction described by Tsou. The constants of tyrosinase and tyrosinase-substrate complex inhibited by 1.0 mmol/L ozagrel have been determined to be 87.28 and 66.07 µmol/L, respectively.

Abstract: To function lipophilic drug Azithromycin (AZM) as ophthalmic preparation, Azithromycin-loaded Nanostructured Lipid Carriers (AZM-NLC) were prepared by High Pressure Homogenization (HPH), and its stability was analyzed afterwards. Well-dissolved lipids of Azithromycin were selected, how the ratio of surfactants to lipids influenced the preparation of AZM-NLC was studied, and mature surfactant system was chosen. The optimized ratio of lipid carriers to emulsifiers [ polyoxyethylene (40) stearate - Poloxamer188 (7:3)] in this study was 1:6, and the final drug-capacity rate was 0.5%. Obtained by photon correlation spectroscopy, the mean particle size of AZM-NLC was 76±2 nm. The results showed that AZM-NLC had kept stable for 15 days, and mean particle size increased to 83 nm after four months.

Abstract: In order to study effects of lysozyme and nisin on fresh-keeping refrigerated fillets, fresh Ctenopharyngodon idellus were slaughtered and washed, then the Ctenopharyngodon idellus were divided into three treatment groups, and dipped in 0.025%, 0.05%, 0.075%, 0.1%, 0.125% lysozyme solution (group A) for 5min, 0.005%, 0.01%, 0.015%, 0.02%, 0.025% nisin solution (group B) for 5min, and Samples in the control treatment had no enzyme added to the water (group C, untreated) for 5min, then kept in 4°C after vacuum packaging. Sensory assessment, pH, total volatile basic nitrogen (TVB-N) and total plate count were determinated to evaluate the fish quality. The result indicated that lysozyme and nisin solution could delay the spoilage of refrigerated fillets fish.

Abstract: Pepsin-soluble collagen (PSC) was successfully extracted from the skin of Amiurus nebulosus. The skin of Amiurus nebulosus was immersed in 0.3 mol/L acetic acid (1: 20, m: V) for 6 h at 37°C, while pepsin was added, at a level of 5000U/g dosage of defatted skin. The maximal yield of the collagen was 97.44%, which was higher than that of acid-soluble collagen (ASC) at 62.05%. Some properties of pepsin-soluble collagens from the skin of Amiurus nebulosus were characterized. Amino acid composition and SDS-PAGE suggested that the collagen might be classified as type I collagen. Moreover, FTIR investigations showed the existence of helical arrangements in PSC of Amiurus nebulosus skin of collagen. There is a possibility to use Amiurus nebulosus skin collagen as an alternative source of collagen for industrial purposes and subsequently it may maximize the economical value of the fish.

Abstract: A novel optical biosensor with gold surface bound silver nanoparticles has been constructed for detection of oncogene of c-Myc tagged DNA plasmid, which exhibited distinct optical properties of localized surface plasmon resonance. The silver colloidal nanoparticles were prepared by using chemical reduction method with sodium citrate, starch and silver nitrate, which were characterized by using UV-Vis absorption spectroscopy, transmission electron microscopy, and cyclic voltammetry, indicating that the silver colloidals were pure, sphere-shaped and narrow- dispersed size distribution with a diameter of 11.70 ± 1.94 nm. The silver nanoparticles were well assembled on the gold substrate with 1,4-dithiothreitol. In the subsequent linking step with compounds of L-cysteine, 3-mercaptopropionic acid, and sodium thioglycolate/HCl, L-cysteine exhibited best characteristics for linking with Ag nanoparticles and formed a nice sensing film by conjugating with a antibody of c-Myc (3C7), mouse monoclonal IgG. The c-Myc antibody immobilized optical biosensor can be well applied to determination of c-Myc tagged DNA plasmid with good regeneration ability. The detection limit was evaluated to be 1.0 pg/μL.

Abstract: Experiments were conducted to investigate the effect of concentration and duration of chlorine dioxide gas treatment on Surface sterilization of grape at 25°C. The results showed that the values of inactivate bacterial log reduction of Botrytis cinerea, Penicillium and alternaria increased with the increasing of ClO₂ gas concentrations and treatment time. When the concentrations and treatment time was about 10 mg/m³ and 30 minutes, respectively, more than 4 log reduction was obtained for the three spoilage bacteria on grape surface. Furthermore, the effect of chlorine dioxide gas treatment on quality of grape was investigated. It was found that the contents of vitamin C (Vc) and reducing sugar (RS) in grape also increased compared with grape without ClO₂ gas treatment.

Abstract: The extraction of total flavonoids from Perilla, using ultrasonic-assisted method, was investigated in this work. Various extraction conditions, such as ethanol concentraction (V/V), volume-weight ratio between the extraction solution and the weight of Perilla (V/W), the extraction time (t), pH, temperature (T), agent concentration (c) have been investigated for their influences. With the help of orthogonal analysis, the optimum extraction conditions have been identified, an extraction rate of 0.97% could be achieved at an ethanol concentration of 60%, an extraction temperature of 50 °C, a volume-weight ratio of 30:1, an ultrasonication time of 50 min. Then 8 samples were screened under this optimal extraction condition, the extraction rate could be 1.71% when use the Perilla leave (production in Linan, Zhenjiang province) as raw material.

Abstract: In this study, we tried to utilize wild jujube as the raw material to produce fruit wine. Grape wine active dry yeast was used for fermentation. The effects of initial sugar content, inoculation concentration of yeast, fermentation temperature and pH were investigated. Fermentation conditions were optimized by orthogonal test. The resulted optimum fermentation conditions were as the following: initial sugar content: 18%, pH value: 4.0, fermentation temperature: 24°C, and inoculum concentration of dry yeast: 0.3%. The produced wine was amber, clear and transparent, fresh jujube fruit aroma, and had mellow and harmonious taste. Its alcohol content was 12.6% vol, the content of residual sugar was 1.5 g/L, vc content was 350 mg/L and total acid were 4.0 g/L.