ABSTRACT
Widespread outbreaks of infectious disease, i.e., the so-called pandemics that may travel quickly and silently beyond boundaries, can significantly upsurge the morbidity and mortality over large-scale geographical areas. They commonly result in enormous economic losses, political disruptions, social unrest, and quickly evolve to a national security concern. Societies have been shaped by pandemics and outbreaks for as long as we have had societies. While differing in nature and in realizations, they all place the normal life of modern societies on hold. Common interruptions include job loss, infrastructure failure, and political ramifications. The electric power systems, upon which our modern society relies, is driving a myriad of interdependent services, such as water systems, communication networks, transportation systems, health services, etc. With the sudden shifts in electric power generation and demand portfolios and the need to sustain quality electricity supply to end customers (particularly mission-critical services) during pandemics, safeguarding the nation's electric power grid in the face of such rapidly evolving outbreaks is among the top priorities. This paper explores the various mechanisms through which the electric power grids around the globe are influenced by pandemics in general and COVID-19 in particular, shares the lessons learned and best practices taken in different sectors of the electric industry in responding to the dramatic shifts enforced by such threats, and provides visions for a pandemic-resilient electric grid of the future.
ABSTRACT
BACKGROUND: Dental instruments, like endodontic files, are hardly disinfected. The aim of this study was to evaluate the efficacy of mechanical, chemical, and ultrasonic (in combinations or separately) techniques for removing debris from files, prior to sterilization. MATERIALS AND METHODS: Totally, 90 new endodontic files with size of 15, 25, and 40 (30 files of each one) were sterilized and one files of each one kept as negative control (NC) group. The rest of files (29 files of each size) were divided into five groups after endodontic therapies and prior to autoclaving: (Positive control [PC]: Without interventions, A: Cleaned with scouring sponge soaked in chlorhexidine 0.2%, B: Stored in Micro 10 enzyme, C: Subjected to Micro 10 enzyme in both conventional and ultrasonic way for 15 min, D: Decontaminated by Micro 10 enzyme with ultrasonic). Finally, the samples were observed under a metallographic microscope, and the data were analyzed by Tuckey, paired t-test, two-way ANOVA tests using SPSS software version 15 at a significant level of 0.05. RESULTS: Significant differences were observed in heads of the files among groups C and PC (P = 0.02), and high amount of debris were seen in the shafts of groups A and D (P < 0.001). The amount of remaining debris were significant in the shafts of sizes 15 (P < 0.001) and 25 (P = 0.01). CONCLUSION: Using Micro 10 in both ultrasonic and conventional methods were acceptable for removing debris from the files. Furthermore, higher amounts of debris were found in the shafts and heads of files with lower sizes (15 and 25).
ABSTRACT
BACKGROUND: Introducing new endodontic cements should await comprehensive investigations and new formulations have to be tested in vivo before applying in human beings. So, the purpose of this study was to compare the biocompatibility of new endodontic cements, calcium aluminate α-aluminate cement (CAAC), calcium aluminate α-aluminate plus cement (CAAC plus), and a mixture of wollastonite and CAAC cement (WOLCA) and mineral trioxide aggregate (MTA), in subcutaneous connective tissue of rats. MATERIALS AND METHODS: Twenty-seven Wistar rats were divided into three groups of 7, 14, and 30 experimental days. Sterile polyethylene tubes were filled with MTA, CAAC, CAAC Plus, and WOLCA cement and implanted subcutaneously. Empty tubes were implanted as negative control. After the experimental periods, animals were sacrificed by anesthetic overdosing. The occurrence of inflammatory responses was scored according to the previously established scores. Data were statistically analyzed using Friedman, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests. The level of significance was 5% (P<0.05). RESULTS: There was a statistically significant difference between experimental and negative control sites in each group (P<0.05). CAAC Plus showed the highest mean scores of inflammation, compared with MTA, CAAC, and WOLCA cement sits at the end of all periods (P<0.05). There were no statistically significant differences between inflammatory scores of each site in different experimental groups, except CAAC plus sites, in which inflammation increased significantly with time (P<0.05). CONCLUSION: According to the results of the current study, biocompatibility of CAAC and WOLCA cement were comparable with that of MTA, but CAAC Plus induced an inflammatory response higher than MTA, therefore is not biocompatible.
