Effect of oral vitamin C on atrial fibrillation development after isolated coronary artery bypass grafting surgery: A prospective randomized clinical trial

Background: Some evidences have shown the role of antioxidant vitamins in preventing atrial fibrillation (AF) after coronary artery bypass grafting (CABG) surgery. We sought to determine the effect of oral vitamin C on the incidence of postoperative AF in patients undergoing elective isolated on-pump CABG surgery. Methods: One-hundred patients who underwent isolated CABG surgery were prospectively assigned into two groups: Group 1 — 50 patients received 2 g of oral vitamin C before and 500 mg twice daily lasting for 5 days after surgery; Group 2 — 50 patients as the control group did not receive any. All patients were continuously monitored after surgery in the intensive careunit (ICU), and then Holter monitoring was implemented for 72 h. Results: The mean of patients’ age was 61.31 ± 6.42 years. Postoperative AF occurred in 16 and 4 patients in control and treatment groups, respectively (32% vs. 8%, p = 0.003). The ICU stay was 1.79 ± 0.313 and 2.10 ± 0.61 days for vitamin C and control groups, respectively (p = 0.002). The hospital stay was significantly lower in vitamin C group compared with that of the control group (5.32 ± 0.59 vs. 5.74 ± 1.30 days, respectively, p = 0.041). Baseline erythrocyte sedimentation rate (OR 1.030, 95% CI 1.003–1.058, p = 0.030) and taking vitamin C (OR 8.068, 95% CI 1.783–36.517, p = 0.007) were the independent predictors of postoperative AF. Conclusions: Oral vitamin C can be safely used to decrease the incidence of postoperative AF in patients undergoing elective isolated on-pump CABG surgery.

Application of information gap decision theory in practical energy problems: A comprehensive review

The uncertainty quantification and risk modeling are hot topics in operation and planning of energy systems. The system operators and planners are decision makers that need to handle the uncertainty of input data of their models. As an example, energy consumption has always been a critical problem for operators since the forecasted values, and the actual consumption is never expected to be the same. The penetration of renewable energy resources is continuously increasing in recent and upcoming years. These technologies are not dispatch-able and are highly dependent on natural resources. This would make real-time energy balancing more complicated. Another source of uncertainty is related to energy market prices which are determined by the market participants’ behaviors. To consider these issues, uncertainty modeling should be performed. Various approaches have been previously utilized to model the uncertainty of these parameters such as probabilistic approaches, possibilistic approaches, hybrid possibilistic-probabilistic approach, information gap decision theory, robust and interval optimization techniques. This paper reviews the research works that used information gap decision theory for uncertainty modeling in energy and power systems.Science Foundation Irelan

Studying the Polypropylenimine-G2 (PPI-G2) Dendrimer Performance in Removal of Escherichia coli, Proteus mirabilis, Bacillus subtilis and Staphylococcus aureus from Aqueous Solution

Abstract Background: Dendrimers are a subset of branched structures that have certain structural order. The aim of this study was to investigate the performance of Polypropylenimine-G2 (PPI-G2) dendrimers in removal of Escherichia coli, Proteus mirabilis, Bacillus subtilis 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 (0.5, 5, 50 and 500 µg/ml) 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, 40, 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: By the increasment of dendrimer concentration and contact time, the number of bacteria in aqueous solution decreased. In times of 40, 50 and 60 minutes, and the concentrations of 50 and 500 µg/ml, all kinds of bacteria in aqueous solution were removed. 0.5 µg/ml of dendrimer concentration had not effect in reducing the number of Escherichia coli and Proteus mirabilis. The effect of dendrimer on gram-negative bacteria was weaker than gram-positive bacteria. Conclusion: Results of this study indicated that PPI-G2 dendrimer is able to remove Escherichia coli, Proteus mirabilis, Staphylococcus aureus and Bacillus subtilis in aqueous solution. However, using dendrimers can be considered as a new approach for drinking water disinfection but it requires further wide range studies