Advanced Materials Research Vols. 834-836

Abstract: The cellulose film was prepared from regenerated cellulose fiber residue by dissolving the cellulose in sodium hydroxide solution at low temperature (-15 °C). The properties of the prepared film were investigated by tensile testing, Scanning Electron Microscope (SEM), X-ray Diffractometer (XRD) and also swelling ratio. Curcumin was added into the film with three different concentrations. The color strength of the curcumin-added film was evaluated and the color change of this film in different pH was also reported.

Abstract: An ultrasound field was applied to obtain Polylactic acid (PLA)/Hydroxyapatite (HAp) biocomposite microspheres with the specific core-shell structure to be applied as a carrier of a drug. The hydroxyapatite was obtained from crocodile bone by thermal process. Sample characterization was achieved by powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) Scanning electron microscopy (SEM) and High Performance Liquid Chromatography (HPLC). As the result, the PLA/HAp loading clindamycin with different polymer-to-ceramic part wt.% ratio (100:0, 90:10, 80:20, and 70:30) showed the agglomeration of sphere-like particles. In addition, the loading efficiency of clindamycin increased with increasing HAp content up to 20%.

Abstract: A series of novel 2-phenylaminopyrimidine (PAP) derivatives structurally related to Imatinib were designed and synthesized. The abilities of these compounds to inhibit proliferation were tested in human chronicmyeloid leukemia K562 cells and HL60cells. Compound (10c) was the most effective cell growth inhibitor in inhibiting K562 cells and compound (10f) was the most effective cell growth inhibitor in inhibiting HL60 cells.

Abstract: Cytotoxic activity of Bufotalin was determined by MTT assay at various concentrations ranging from 0.002 to 0.008 μmol/ml on Hela cells. The Apoptosis and its mechanism induced by Bufotalin was also studied. The results showed Bufotalin displayed the marked inhibition effect to Hela cells and the IC₅₀ value is 0.0045 μmol/ml for 24 hour. The procaspase-3,-8 and-9 decreased and their active cleaved forms increased treated with Bufotalin at concentrations from 0.002 to 0.006 μmol/ml. These data suggest that the pro-apoptotic effect of Bufotalin is mediated through activation of caspases and mitochondria in Hela cells.

Abstract: Ganoderic acid R (GA-R) possessed significant cytotoxicity on a multidrug resistance (MDR) tumor cell line (KB-A-1/Dox) and a sensitive tumor cell line (KB-A-1). The results indicated that the inhibition effect of the GA-R was due to the induction of apoptosis. The use of GA-R in vitro resulted in a restoration response of the KB-A-1/Dox cells to the anti-tumor drug doxorubicin by stimulating the drug accumulation within the cells. The index of MDR reversion of GA-R was about 22 folds. The findings show that the ganoderma triterpene may be good candidates for anti-tumor and anti MDR chemotherapy.

Abstract: Flavonoids was isolated from canavalia maritime by accelerated solvent extraction (ASE) coupled with high-speed counter-current chromatography (HSCCC). The antioxidant activities of flavonoids were investigated in vitro and evaluated by IC₅₀. The results indicated that flavonoids possessed obvious reducing power and significant inhibitory effects on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical. These results suggest that canavalia maritime flavonoids could be a suitable natural antioxidant for humans.

Abstract: The study aimed to investigate the selective blue-laser lithography that can fabricate the biomedical materials. The major advantage of using blue-laser instead of UV laser is to lower the machine and operating costs but still keeping the proper part quality for biomedical applications. The material used in the study is the bisphenol a diglycidylether methacrylate (BisGMA) which is specific formulated for photo-polymerizing with blue laser (wavelength = 473nm). The fabricated parts were preliminarily examined by flexural strength testing and in vitro testing of toxicity by direct contact test. The results showed that the flexural strength of fabricated part was about 92% as compared to the flexural strength of hand-pressed PMMA. The in vitro testing of toxicity, confirmed that the fabricated part by the selective blue-laser lithography with BisGMA material has good biocompatibility.

Abstract: The dissolution process of galvannealed (GA) and galvanized (GI) coating was examined by correlating a chemical stripping test in 1MNaCl+0.01MH₂SO₄ solution. The key time of dissolution process of coating was found via measuring the variation of free corrosion potential. Through coating metallographic observations at the key point, the dissolution process of coating can be clear. There are four Fe-Zn intermetallic phases in GA coating, namely gamma-1,gamma,delta and zeta phases, from the substrate. The compressed part of GA and GI coatings was the initial of corrosion process. The net crack will be emerging on the delta phase, which width graduallyincreasing until stripping. Pitting corrosion occurred on the GI coating in the solution containing Cl^- ion, the area and depth of pit gradually increasing until stripping. The corrosion potential of Fe₂Al₅Zn_x inhibition layer is about-0.8VSCE.

Abstract: In this paper, mechanical analysis of water striders legs floating on water surface was conducted, and the supporting force model of water striders flexible legs was established. The maximum dimple depth and maximum supporting force of water striders leg on water surface were measured. Furthermore, the maximum supporting forces of water striders fore leg, mid leg and hind leg were respectively calculated according to the established model, which were compared with the measured values, with error rate lower than 2.9%, 3.7% and 3.9% respectively.

Abstract: Hot Dip Zn-6Al-3Mg-0.2Si coating steel sheet was prepared in laboratory by Hot-dip Galvanizing Simulator produced by National Engineering Lab of Advanced Coating Technology for Metal Materials. The surface and cross sectional microstructure of the samples were analyzed by using SEM and EDS. Hot dip Zn coated, 55Al-43.3Zn-1.6Si and Zn-6Al-3Mg-0.2Si coated steel sheet samples were exposed to standardized salt spray test. The Zn-6Al-3Mg-0.2Si coating and its erode production were investigated by XRD. The results showed that the hot dip Zn-6Al-3Mg-0.2Si coating had better corrosion resistance than ordinary galvanized layer.