Citizen Responder Activation in Out-of-Hospital Cardiac Arrest by Time of Day and Day of Week

BACKGROUND: We aim to examine diurnal and weekday variations in citizen responder availability and intervention at out‐of‐hospital cardiac arrest (OHCA) resuscitation. METHODS AND RESULTS: We included confirmed OHCAs where citizen responders were activated by a smartphone application in the Capital Region of Denmark between September 1, 2017 and August 31, 2018. OHCAs were analyzed by time of day (daytime: 07:00 am–03:59 pm, evening: 4:00–11:59 pm, and nighttime: 12:00–06:59 am) and day of week (Monday–Friday or Saturday–Sunday/public holidays). We included 438 OHCAs where 6836 citizen responders were activated. More citizen responders accepted alarms in the evening (mean 4.8 [95% CI, 4.4–5.3]) compared with daytime (3.7 [95% CI, 3.4–4.4]) and nighttime (1.8 [95% CI, 1.5–2.2]) (P<0.001), and more accepted alarms during weekends (4.3 [95% CI, 3.8–4.9]) compared with weekdays (3.4 [95% CI, 3.2–3.7]) (P<0.001). Proportion of OHCAs where at least 1 citizen responder arrived before Emergency Medical Services were significantly different between day (42.9%), evening (50.3%), and night (26.1%) (P<0.001), and between weekdays (37.2%) and weekends (53.5%) (P=0.002). When responders arrived before Emergency Medical Services, there was no difference of bystander cardiopulmonary resuscitation or defibrillation between daytime, evening, and nighttime (P=0.75 and P=0.22, respectively) or between weekend and weekdays (P=0.29 and P=0.12, respectively). CONCLUSIONS: Citizen responders were more likely to accept OHCA alarms during evening and weekends, with the highest proportion of responders arriving before Emergency Medical Services in the evening. However, there was no significant difference in delivering cardiopulmonary resuscitation or early defibrillation among cases where citizen responders arrived before Emergency Medical Services. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03835403

Performance evaluation of conductive additives for activated carbon supercapacitors in organic electrolyte

In this study, we investigate two different activated carbons and four conductive additive materials, all produced in industrial scale from commercial suppliers. The two activated carbons differed in porosity: one with a narrow microporous pore size distribution, the other showed a broader micro-mesoporous pore structure. Electrochemical benchmarking was done in one molar tetraethylammonium tetrafluoroborate in acetonitrile. Comprehensive structural, chemical, and electrical characterization was carried out by varied techniques. This way, we correlate the electrochemical performance with composite electrode properties, such as surface area, pore volume, electrical conductivity, and mass loading for different admixtures of conductive additives to activated carbon. The electrochemical rate handling (from 0.1 A g−1 to 10 A g−1) and long-time stability testing via voltage floating (100 h at 2.7 V cell voltage) show the influence of functional surface groups on carbon materials and the role of percolation of additive particles