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Objective: To investigate the effects of ZnO nanoparticles (ZnO NPs) on proliferation and apoptosis of human lung epithelial cells BEAS-2B and its molecular mechanisms., Methods: BEAS-2B cells were treated with ZnO NPs at concentrations of 3, 6 and 12 μg/ml for 12 h and 24 h, the control group was not treated with ZnO NPs, each with 3 replicate wells. Cell viability was detected by CCK-8 method, and the half lethal concentration (IC 50 ) was analyzed. Then, the BEAS-2B cells were treated with ZnO NPs at selected concentrations of 3 and 6 μg/ml for 24 h respectively,each group was set with 3 replicate. Cell morphology was observed under inverted microscope. The morphology of cell nuclei was observed by Hochest33342 staining. The morphology of apoptosis was observed by AO staining and scanning electron microscopy. Cell cycle progression, cell apoptosis rate and the level of reactive oxygen species(ROS)were detected by flow cytometry. Western blot was used to detect the expression levels of Bcl-2 and Bax protein., Results: Compared with the control group, the cell viability of cells treated with ZnO NPs were decreased significantly( P ＜0.01), and the IC 50 was 6.13 μg/ml at 24 h of drug treatment. After the cells were treated with ZnO NPs for 24 h, the levels of ROS were increased significantly( P ＜0.05, P ＜0.01)in 3 μg/ml, 6 μg/ml groups. The cell cycle was arrested at G2/M phase, chromatin condensation and apoptotic bodies were induced, apoptosis rate was increased significantly( P ＜0.01) in 6 μg/ml group. The expression of Bcl-2 was decreased( P ＜0.05), and the expression of Bax was increased ( P ＜0.05) in cells treated with 6 μg/ml ZnO NPs for 24 h., Conclusion: ZnO NPs induced ROS accumulation, blocked progress of cell cycle and induced cell apoptosis in BEAS-2B cells.

Objective: The aim of this study is to analyze the processing mechanism of calamine., Method: XRD, TEM and IR were adopted to analyze the structures and the components of original and calcined calamine. Their antibacterial activities were also determined., Result: The results indicated that zinc carbonate in original calamine was decomposed into zinc oxide after processing at 700 degrees C for 1 hour using original calamine of 40 mesh, and the particle size was smaller than before processing. All of ZnO, ZnCO3 and Zn5 (CO3) 2 (OH) 6 had antibacterial activitives., Conclusion: Original calamine is deposed to ZnO after being calcined for 1 h at 700 degrees C and wet milling. The content of ZnO and antibacterial activity of calcined calamine are better than those of original calamine, moreover, the particle size diminishes and become dimensional uniformity, and the contents of dissolved impurities is decreased. The antibacterial activitives of original and calcined calamine are decided by zinc.

Objective: To evaluate effects of incorporating tetrapod-like zinc oxide whisker (T-ZnOw) antibacterial agent on the antibacterial activity of composite resin, compared with that of the silver-based inorganic antibacterial agent., Methods: The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the two different antibacterial agents against Streptococcus mutans were investigated using the broth dilution test. Then the antibacterial activities of the self-cured composite resin specimens with different incorporating concentrations of the two antibacterial agents were evaluated using direct contact test. And the antibacterial activities of the resin specimens were examined again after 3 months of accelerating aging., Results: The MIC (MBC) of the T-ZnOw antibacterial agent and silver-based inorganic antibacterial agent were 0.15625 (0.3125) g/L and 0.15625 (0.15625) g/L. When the concentrations of T-ZnOw added to composite resin were 3%, 5%, and 10% (w/w), the antibacterial ratios of the resin specimens were (84.85+/-5.16)%, (94.22+/-3.73)%, and (99.43+/-0.48)% respectively. When the concentrations of the silver-based antibacterial agent added to composite resin were 1%, 3%, and 5%, the antibacterial ratios were (71.01+/-7.67)%, (90.76+/-5.91)%, and (97.19+/-4.10)% respectively. The antibacterial ratios of the resin specimens containing 5% of both antibacterial agents were (89.89+/-5.55)% and (78.79+/-7.81)% respectively after 3 months of accelerating aging., Conclusions: Incorporation of the T-ZnOw antibacterial agent in composite resin can improve the antibacterial performance of the resin, and the resin exhibits better antibacterial performance than that incorporating silver-based inorganic antibacterial agent after 3 months of aging.

Objective: To study processing method and mechanism of Calamine., Method: Thermogravimetry analysis method and nano-technology were adopted to analyze and synthesize the components in Calamine, Tetracycline was took as the comparison drug to determine the antibacterial activity of Calamine and its components., Result: A part of zinc carbonate in Calamine was decomposed into zinc oxide when processing, and the particle size was smaller than before. The antibacterial activity of Calamine is decided by the content and particle size of zinc oxide, and has nothing with zinc carbonate. The more content and the smaller particle size of zinc oxide, the more powerful antibacterial activity of Calamine., Conclusion: The content and the particle size of zinc oxide can be the important targets in the processing of Calamine.