Advanced Materials Research Vols. 1120-1121

Abstract: In this study,the cellulase-producing ability of Aspergillus niger FC-1 through solid-state fermentation (SSF) and characteristics of the cellulase were investigated. The maximum activities of total cellulase (FPase) and endoglucanase (CMCase) were 8.2 and 31.5 IU per gram of dried substrate respectively after 96-h incubation period. The activities of both FPase and CMCase produced by Aspergillus niger FC-1 exhibited the optimal values at pH 5.5 and 50°C(as shown in Fig.2). Thermostability and pH stability of the enzymes were respectively appreciable at temperature ranging from 45°C to 55°C, pH ranging from 5.0 to 5.5. In addition, with an optimal 1:10 (w/v) substrate to moisture ratio (a cellulase loading of 8.5 FPU per cellulose), the glucose concentration was as high as 36.6 g glucose l^-1 for a 48 h hydrolysis of corncob residues.

Abstract: Delivery systems play important roles in improving drug efficacy. In particular, insoluble functional pigments must be handled carefully when increasing their solubility, in order to ensure that they remain active. In this study, the nanoparticles were coated by the oil phase in the microemulsion system (NPs-SEs), and this system was found to both increase the stability of the drug and improve drug loading. NPs-SEs containing lycopene, soybean oil, Span-40, Tween-20, stabilizer and glycerol were prepared by high pressure homogenization technology. It was characterized and its droplet size, and Zeta potential were 181±15 nm ( PDI 0.092±0.01), -70.83±1.64mV, respectively. The drug loading capacity of NPs-SEs was 1.02±0.16mg/ml and was nearly 4 times more than the highest concentration of lycopene O/W emulsion.

Abstract: Magnetic metal silica submicrospheres were produced from silica coated on magnetic nanoparticles using well controlled hydrothermalled method and were characterized by TEM, XRD, FTIR, XPS. The well-designed mesoporous magnetic metal silciate had a large specific area, high magnetization. Firstly, SiO₂-coated maghemite (Fe₃O₄@SiO₂ composites) were synthesized by an sol-gel method, in which the iron ferrous chloride as well as TEOS acted as the precursor for maghemite and SiO₂, respectively. The Fe₃O₄@SiO₂ composites revealed a core-shell structure, Then, Fe₃O₄@SiO₂/X₃Si₂O₅(OH)₄(X = Ni, Cu, Zn) was obtained by hydrothermalled with metal chloride. The resulting composites show not only a magnetic response to an externally applied magnetic field, but also can be a good adsorbent for bovine hemoglobin in the ambient temperature.

Abstract: In this study, we synthesized carboxymethyl chitosan-graft-poly(ε-caprolactone) (CMCS-g-PCL) by grafting ε-CL onto the hydroxyl groups of CMCS via ring-opening polymerization. The graft copolymers were characterized by ¹H NMR spectroscopy and thermogravimetric analysis (TGA). Then use the graft copolymer to produce the micelle by solvent-evaporation method. The DLS and TEM were utilized to evaluate the particle size and morphology and showed that the micelles were in a well-defined spherical shape with a uniform size distribution. The results indicated that the size of range is below 200 nm and could be used as drug carrier and have better active cellular uptake.

Abstract: A series praziquantel-loaded poly(lactide-co-glycolide) implants are prepared by melt extrusion. The morphologies, structures and the in vitro releases are investigated. The results show that PZQ is dissolved or dispersed in the PLGA matrix and its crystal structure can be transformed into amorphous filament or flake-like structure. The in vitro release increased with the increase of the amount of low molecular weight PLGA0.13. The release of PZQ from the implant with a length of 20 mm is faster than that from that with a length of 10 mm. The macroscopic change and release curves of the implants reveal the drug release from the implants can be controlled by initial diffusion of drug from near the surface of implants followed by elution during polymer erosion.

Abstract: Curcuma zedoaria (Berg.) Rosc. (Zingiberaceae) has long been used as a folk medicine. Volatile compounds were extracted from the rhizome using supercritical carbon dioxide at 10 MPa and 45oC. Totally, 31 compounds, including 15 terpenes, nine alcohols, six ketones and one other compound, were identified. Aqueous and methanolic extracts were prepared from dried rhizome and the methanolic fractions were prepared using silica gel column chromatography. Aqueous and methanolic extracts were extremely effective in antioxidant activity by the 1,3-diethyl-2-thiobarbituric acid method and EC₅₀ (effective concentration at 50%) values of <10 μg/mL. EC₅₀ values of aqueous methanolic and supercritical carbon dioxide extracts in antioxidant activities by the thiobarbituric acid-reactive substances and conjugated diene methods were 6.58-8.86 and 0.43-0.67 mg/mL, respectively. The methanolic extract was more effective in reducing power, scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals and chelating ability on ferrous ions. Based on the results obtained, all extracts showed effective antioxidant properties.

Abstract: The differences of growth and root absorption of three apple rootstock seedlings was compared and the absorption of hydrogen ions and endogenous hormone levels under the replant stress was discussed in this study. Experimental results showed that the dry matter of M. sieversii seedlings was significantly decreased under replant stress and the root-shoot ratio was increased. Root biomass of three rootstocks increased observably and the total root length was extended by 1.45 times, 2.22 times, 1.71 times, respectively compared to control. Root activity of three rootstocks all decreased, which one of M. hupehensis fell less than another two rootstocks. The flux direction of H⁺ had no change for M. Hupehensis and M. Hupehensis, which of M. prunifolia changed into outward from inward. The endogenous hormone level of three rootstocks in replant stress was affected. ABA content is higher than that of controls, IAA and ZR contents were lower than controls, GA in M. Hupehensis and M. prunifolia was higher than that of controls besides M. Sieversii. The root amount of three rootstocks increased significantly. The dry matter accumulation, absorption of H⁺ and endogenous hormone levels was affected and the sequence decreasingly was M. Hupehensis, M. prunifolia and M. Sieversii according to the degree of tolerance to replant stress.

Abstract: Porous Ti with an average pore size of 200-400 μm and porosity in the range of 25-50% has been manufactured using polymethyl methacrylate (PMMA) powders as spacer particles. The stress distribution of porous Ti was analyzed by Ansys software. The stress is prone to focusing on the surrounding of connected pore and weak cell. As the porosity and pore size increase, the concentration factor of stress increases due to the lager degree of pore connection and aggregation. Comparing with the ellipsoid pore model, the concentration factor of stress of the porous Ti with spherical pore is lower.

Abstract: By adding Mn into SAE8620 gear steel, the effect of Mn on the microstructure and hardness of steel treated by quenching and partitioning process is investigated in this research. Microstructure is observed. Hardness is measured, after that it is converted into tensile strength. And the content of austenite is determined by X-ray diffraction analysis. It is found that higher content of Mn increases the content of martensite and reduces that of blocky ferrite and also leads to higher hardness of steel. In addition, XRD pattern shows obvious existence and enhancement of retained austenite.

Abstract: With copper bar as the research object, using ANSYS Workbench to analyze the temperature distribution and characteristics of copper bar under different thermal conditions and the same current load, provide a basis for the choice of the design of the copper.