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Objective To explore the effect of heat treatments on the metal⁃ceramic bonding strength in Ni⁃Cr⁃Ti al⁃ loy and Ni⁃Cr alloy. Methods We evaluated the metal⁃ceramic bond strengths by using a three⁃points bending test ac⁃ cording to ISO 9693. Meanwhile, we also observed the metal⁃ceramic interface through scanning electronic microscope (SEM) and energy dispersive spectrum (EDS). Results The mean value of bonding strengths of four groups were (38.04 ± 3.79) MPa (Ni⁃Cr⁃Ti, degassed), (32.17 ± 4.00) MPa (Ni⁃Cr⁃Ti, no heat treatment), (36.32 ± 7.41) MPa (Ni⁃Cr, de⁃ gassed), (31.75±2.77) MPa (Ni⁃Cr, no heat treatment). The statistic analysis showed that the mean bonding strengths were affected significantly by heat treatment method (P = 0.001), but not alloy type (P = 0.484). SEM and EDS demon⁃ strated that the bonding surfaces of degassed specimens were compacted and had no cracks unlike those of specimens not receiving heat treatment. Conclusion According to the test results, the metal⁃ceramic bonding strengths of Ni⁃Cr⁃Ti alloy and Ni⁃Cr alloy are close to each other, and the bonding strengths of alloys can be heightened by heat treatment.

PURPOSE: To investigate and compare the effect of different heat treatment on the metal- ceramic bonding strength and the interfacial microstructure of the Co-Cr alloy. METHODS: Thirty specimens were made according to ISO 9693, and then divided into 3 groups (n=10) through the measurements. Group A (degassed 60s): degassed and then maintained 60s in 980°C; Group B (degassed 60s and preoxidation 60s): degassed and maintained 60s in 980°C, then were maintained continuously for 60s in 980°C after re-gassed; Group C (degassed 120s): degassed and maintained 120s in 980°C. The bonding strengths of the three groups were evaluated through three point bending test. Six specimens divided into 3 group were made in the same method to observe the metal-ceramic interface through scanning electronic microscope (SEM) and energy dispersive spectrum (EDS). The bonding strength data were analyzed using ANOVA and Bonferroni's test by SPSS13.0 software package. RESULTS: The mean value of bonding strength was (39.03±2.70) MPa for group A, (34.43±2.36) MPa for group B, (31.65±1.49) MPa for group C, respectively. There were significant difference between every two groups (P<0.05). SEM demonstrated that the width of interfacial transition layer was 12.3-16.4 µm in group A, 15.2-21.8 µm in group B and 26.3-32.2 µm in group C. CONCLUSIONS: Higher metal-ceramic bonding strength for Co-Cr alloy will be formed under the situation of degassed, and maintained 60s in 980°C; while extending degassed time, prolonging the heat maintained time and preoxidation after degassing will reduce metal-ceramic bonding strength. Supported by Guangdong Provincial Science and Technology Research Project (2006B36006016) and Guangzhou Municipal Science and Technology Research Project(2005Z3-E0531). [ABSTRACT FROM AUTHOR]

We synthesized eight tanshinone anhydrides and the alcoholytic derivatives through a mild oxygen-insertion under Pd/C catalytic hydrogenation conditions. The suppressive effects of the anhydrides on the oxidized low-density lipoprotein (oxLDL) uptake and the oxLDL-induced macrophage-derived foam cell formation were studied. Our results revealed that both anhydrides 1a and 2a could significantly suppress the oxLDL uptake in macrophages and the foam cell formation at micromolar level, which might be partially attributed to their inhibition of oxLDL-induced LOX-1 expression in macrophages.

Objective: To study the formulation and preparation of ampelopsin liposomes and evaluate their quality., Method: The liposomes were prepared by a film-ultrasonic dispersion technique. Served as quota with the entrapment ratio and appearance and diameter of the liposomes, the optimal formulation and preparation were selected by means of an uniform design test. The appearance of liposomes was observed by micrography. The diameter and electric charge of surface were determined by granularity mensuration instrument. The entrapment ratio and the leakage rate of ampelopsin liposome were determined by means of dialyze. The content of ampelopsin was determined by UV., Result: The result of electron micrography and the size distribution showed that the liposomes were similar to spherical small unilamellar vesicles. The mean diameter was (258.2 +/- 51.2) nm and the electric charge of surface is 19.0 mV. The entrapment ratio of ampelopsin liposomes was 62. 3% and the lecithoid oxidative rate was 0.83% (n = 3)., Conclusion: The selected formulation and preparation of ampelopsin liposomes is efficient and practicable.

Objective: To investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4., Methods: Through anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HIV-1 infection was verified. Chemotaxis assay was performed to show the ability to induce PBMCs migration by ampelopsin, RANTES and SDF-1alpha. Fluorescence labelling monoclonal antibody was utilized to observe the interaction of ampelopsin and CXCR4. Mice immunosuppressant model was also established to detail the role ampelopsin played in regulating cellular immunological functions., Results: Ampelopsin could protect sensitive cells against HIV-1 infection and dramatically reduce HIV-1 antigen P24 expression. HIV-1SF33 attaching to MT-4 cells was interfered by ampelopsin, and the EC50 was 0.175 mg/mL for cellular protection and 0.024 mg/mL for P24 inhibition. At co-cultivating phase, EC50 was 0.229 mg/mL and 0.197 mg/mL respectively. Furthermore, the EC50 was 0.179 mg/mL and 0.348 mg/mL in acute infection. Human PBMCs migration was induced after being challenged with ampelopsin or chemokines, and synergistic action was observed during co-treatment. Ampelopsin alone resulted in maximal chemotaxis at 1 mg/mL. HIV-1 co-receptor CXCR4 on the surface of PBMCs was decreased by internalization, which indicated the effect of ampelopsin on CXCR4. About 70% CXCR4 was reduced by ampelopsin at 1 mg/mL. Ampelopsin also augmented cellular immunological functions in immunosuppressive mice., Conclusion: Ampelopsin displays a strong inhibitive role during HIV-1 absorption, incubation and acute infection. These results are coincident with its immune enhancement.