Background: Dendrimers are macromolecules with regular three-dimensional structure that have many branches. The aim of this study was to investigate the fficiency of Nano Polyamidoamine–G5 (NPAMAM-G5) dendrimers in removal of Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus from aqueous solution.

Materials and Methods: In this experimental study, initially, dilution of 10³ CFU/ml was prepared from each strain of bacteria. Then, different concentrations of dendrimers (0.025, 0.25, 2.5 and 25 µg/ml) in the ambient temperature (23-25°C) was added to water. In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 50 and 60 min) and were cultured on nutrient agar medium. Samples were incubated for 24 hours at 37 ° C and then the number of colonies was counted.

Results: There is a direct relation between antibacterial properties of dendrimers in aqueous solution and increasing the dendrimer concentration and contact time. At a concentration of 25 μg/ml and 60 minutes, all kinds of bacteria except Staphylococcus aureus, and at 30 minutes, E. coli and Klebsiella bacteria, were removed by 100% The concentration of 2.5 μg/ml at 60 minutes of  bacteria, Escherichia coli, Klebsiella and Proteus mirabilis, 100% Were removed. All concentrations of dendrimer at different times were reduced bacteria.

Conclusion: Results of this study indicated that NPAMAM–G5 dendrimer is able to remove Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus from aqueous solution.

Background: Childbirth is a stressful event that requires a mental adjustment. Optimism is one of the important determinants of psychological adjustment which is a combination of interest and positive attitude. The purpose of this study was to determine the effect of optimism training during pregnancy on attitude and intentions to choose the mode of delivery in nulliparous women.

Materials and Methods: In this clinical trial , 64 primipar pregnant women with normal pregnancies, 34-30 weeks, without indication for cesarean section referring to the health centers in Mashhad in 2014 were selected and were randomly divided into two groups , A (trained) and B (no training). Optimism training during 5 session of the 60-minute, with the group participation of participants and active exercises was conducted. Data were analyzed with using the software SPSS and statistical tests including variance analysis, Fischer exact test, willcoxon, Square-Chi and paired t-test.

Results: Average attitude score towards c/s delivery in the study group, before and after training has a significant difference (p<0.001). Average attitude score towards natural childbirth was significantly higher in intervention group compared to the control group (p<0.002). Frequency of intentions to choose the mode of delivery in the study group, before and after training has a significant difference (p<0.033).

Conclusion: Reults showed that optimism training in creating a positive attitude towards natural childbirth and thus reducing the rate of elective c/s delivery is effective.