The newly emerged Coronavirus Disease 2019 (COVID-19) rapidly outspread worldwide and now is one of the biggest infectious pandemics in human society. In this study, the inhibitory potential of 99 secondary metabolites obtained from endophytic fungi was investigated against the new coronavirus RNA-dependent RNA polymerase (RdRp) using computational methods. A sequence of blind and targeted molecular dockings was performed to predict the more potent compounds on the viral enzyme. In the next step, the five selected compounds were further evaluated by molecular dynamics (MD) simulation. Moreover, the pharmacokinetics of the metabolites was assessed using SwissADME server. The results of molecular docking showed that compounds 18-methoxy cytochalasin J, (22E,24R)-stigmasta-5,7,22-trien-3-β-ol, beauvericin, dankasterone B, and pyrrocidine A had higher binding energy than others. The findings of MD and SwissADME demonstrated that two fungal metabolites, 18-methoxy cytochalasin J and pyrrocidine A had better results than others in terms of protein instability, strong complex formation, and pharmacokinetic properties. In conclusion, it is recommended to further evaluate the compounds 18-methoxy cytochalasin J and pyrrocidine A in the laboratory as good candidates for inhibiting COVID-19.

Introduction. Early childhood caries is a kind of caries occurring in deciduous teeth. Bacteria are among the main factors. Antibacterial agents such as fluoride are used in both prevention and treatment, but their application in children faces limitations such as fluorosis. Therefore, novel methods of caries prevention among the children are mainly focused on the use of fluoride-free active ingredients. In this comparative study, antibacterial effects of gels containing propolis and aloe vera, fluoride, xylitol, and CPP-ACP were investigated. Methods. This is an in vitro study. By plate well technique, plates containing gels were created in the culture medium of Streptococcus mutans and Lactobacillus, and their antibacterial impacts were evaluated by measuring the inhibition zone after 24, 48, and 72 hours. Then, different concentrations of each gel were evaluated in the same way for the antibacterial properties. For each sample, this process was iterated 3 times, where the average was declared as the final number. The collected data were entered in SPSS 24. Results. In both bacteria, propolis gel and aloe vera had the highest zone of inhibition, followed by fluoride and xylitol in the second and third places, respectively. Different concentrations of gels are significantly different in terms of antimicrobial effect (P value ≤ 0/05). The antimicrobial effect of propolis and aloe vera gel was kept up to the concentration of 1 / 16 . As the bacterial and gel contact time is prolonged, the antibacterial effect of different gels increases, but the difference is not statistically significant (P value = 0.109). CPP-ACP gel had no antimicrobial effect at any concentration. Conclusion. Propolis and aloe vera gel had a greater antimicrobial effect than other gels, where such effect was observed in low concentrations. CPP-ACP gel had no antimicrobial properties.

Background. Nowadays, dental treatment under general anesthesia is accepted as a treatment method in children in which other common methods do not allow to achieve acceptable results. The benefits of general anesthesia in pediatric dental treatment are that the treatment is completed in one session, the person is relieved of pain, and most importantly, the child does not need to cooperate. However, it is important to determine the exact dental reasons for children under general anesthesia. Objective. In this study, the cause of dental treatment under general anesthesia in children was examined from the perspective of specialists, assistants, and parents of children under general anesthesia. Methods. In this descriptive-analytical cross-sectional study, participants were selected from among the parents of children under general anesthesia for dental treatment and pediatric dentists and assistants in a purposeful manner. After the items were prepared by the professors, the prepared checklist was read to the people. After completing the checklist, the data were entered into SPSS software version 20 and analyzed using descriptive statistics such as frequency determination, mean, and statistical rests. Results. According to the consensus of parents and experts, the main reasons for general anesthesia for children to perform their dental operations were: young age, lack of cooperation during previous dental treatment, a large number of dental treatments, systemic disease of the child, unwillingness of parents to perform behavioral control procedures, higher quality work under anesthesia, mental and physical behavioral problems, and reduced number of treatment sessions. Conclusion. Therefore, reasons such as young age, lack of cooperation, and a large number of dentist’s work are among the most important factors that lead to the decision to perform general anesthesia in children. In light of this decision, the consequences and disadvantages/advantages of this method are important and therefore more research should be done on this issue.