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Silver doped zinc sulphide nanoparticles were synthesised by a microwave-assisted polyol method. Characterisation of nanoparticles was performed using XRD, FESEM-EDXand UV-visible spectroscopy to investigate chemical structure, crystalline phase, particle size and surface morphology. Antibacterial properties of synthesised nanoparticles were investigated by determining their MIC and MBC values and kinetic of bactericidal activity against Staphylococcus aureus(ATCC 6538) and Escherichia coli(ATCC 25922). Characterisation of the synthesised nanoparticles showed formation of single phase of hexagonal wurtzite ZnS structure with Ag+ substitution at 1.6% Zn/Ag molar ratio. MIC values were determined as 250 and 500 µg/ml against Staphylococcus aureus and Escherichia coli, respectively and time kill profiles showed efficient and rapid bactericidal activity of the synthesised Ag-doped ZnS nanoparticles. Results of this study suggest a synthesis strategy for Ag-doped ZnS nanoparticles with potent and broad spectrum antibacterial properties that can widen the range of applications of these nanoparticles. [ABSTRACT FROM AUTHOR]

Purpose: This study investigates the protective properties of Myrtus communis extract against the oxidative effects of extremely low-frequency magnetic fields (ELFMF). Also, this study is aimed to analyze the conformational changes of hemoglobin, oxidative damages to plasma proteins and antioxidant power of plasma following exposure to ELFMF. Materials and methods: Adult male rats were divided into 3 groups: (1) control, (2) ELFMF exposure, and (3) ELFMF exposure after M. communis extract administration. The magnetic field (0.7 mT, 50 Hz) was produced by a Helmholtz coil for one month, 2 hours a day. The M. communis extract was injected intraperitoneally at a dose of 0.5 mg/kg before exposure to ELFMF. The oxidative effects of ELFMF were studied by evaluating the hemoglobin, methemoglobin (metHb) and hemichrome levels, absorption spectrum of hemoglobin (200-700 nm), oxidative damage to plasma proteins by measuring protein carbonyl (PCO) levels and plasma antioxidant power according to the ferric reducing ability of plasma (FRAP). The mean and standard errors of the mean were determined for each group. One-way ANOVA analysis was used to compare the means of groups. The significance level was considered to be p < .05. Moreover, artificial neural network (ANN) analysis was used to identify the predictive parameters for estimating the oxyhemoglobin (oxyHb) concentration. Results: Exposure to ELFMF decreased the FRAP which was in concomitant with a significant increase in plasma PCO, metHb and hemichrome concentrations (p < .001). Oxidative modifications of Hb were shown by reduction in optical density at 340 nm (globin-heme interaction) and 420 nm (heme-heme interaction). Administration of M. communis extract increased FRAP values and decreased plasma POC, metHb, and hemichrome concentrations. Also, a significant increase in Hb absorbance at 340, 420, 542, and 577 nm showed the protective properties of M. communis extract against ELFMF-induced oxidative stress in erythrocytes. ANN analysis showed that optical absorption of hemoglobin at 520, 577, 542, and 630 nm and concentration of metHb and hemichrome were the most important parameters in predicting the oxyHb concentration. Conclusions: Myrtus communis extract enhances the ability of erythrocytes and plasma to deal with oxidative conditions during exposure to ELFMF. Also, ANN analysis can predict the most important parameters in relation to Hb structure during oxidative stress. [ABSTRACT FROM AUTHOR]