Dual-additive-based electrolyte design for aqueous zinc ion batteries with high plating/stripping efficiency.

A dual-additive-based aqueous electrolyte was designed with a pH-buffering additive (Zn(OAc)2) and an electrostatic shielding additive (TMAOAc) for high Zn plating/stripping efficiency. The buffering pair, OAc-/HOAc, can stabilize the pH value to suppress side hydrogen evolution reactions. Meanwhile, TMA+ acts as a competitive cation being preferentially adsorbed on the uneven surface of the Zn anode and exerts an electrostatic shielding effect to facilitate flat Zn deposition. Such a dual-additive-based electrolyte promotes an ultra-high Zn plating/stripping efficiency of 99.9% at 1 mA cm-2 and long-term cycling stability for 3600 h at 0.5 mA cm-2, offering valuable insights for advanced aqueous batteries.

High Power- and Energy-Density Supercapacitors through the Chlorine Respiration Mechanism.

Supercapacitor represents an important electrical energy storage technology with high-power performance and superior cyclability. However, currently commercialized supercapacitors still suffer limited energy densities. Here we report an unprecedentedly respiring supercapacitor with chlorine gas iteratively re-inspires in porous carbon materials, that improves the energy density by orders of magnitude. Both electrochemical results and theoretical calculations show that porous carbon with pore size around 3 nm delivers the best chlorine evolution and adsorption performance. The respiring supercapacitor with multi-wall carbon nanotube as the cathode and NaTi2 (PO4 )3 as the anode can store specific energy of 33 Wh kg-1 with negligible capacity loss over 30 000 cycles. The energy density can be further improved to 53 Wh kg-1 by replacing NaTi2 (PO4 )3 with zinc anode. Furthermore, thanks to the extraordinary reaction kinetics of chlorine gas, this respiring supercapacitor performs an extremely high-power density of 50 000 W kg-1 .

Serial Interval and Reproductive Number of COVID-19 Among 116 Infector-infectee Pairs - Jingzhou City, Hubei Province, China, 2020.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: The key epidemiological parameters including serial interval, basic reproductive number (R 0), and effective reproductive number (R t) are crucial for coronavirus disease 2019 (COVID-19) control and prevention. Previous studies provided different estimations but were often flawed by some limitations such as insufficient sample size and selection bias. WHAT IS ADDED BY THIS REPORT?: In this study, a total of 116 infector-infectee pairs meeting strict inclusion criteria were selected for analysis. The mean serial interval of COVID-19 was 5.81 days (standard deviation: 3.24). The estimated mean with 95% confidence interval of R 0 was 3.39 (3.07-3.75) and 2.98 (2.62-3.38) using exponential growth (EG) and maximum likelihood (ML) methods, respectively. The R t in the early phase of the epidemic was above 1 with the peak of 4.43 occurring on January 8, and then showing subsequent declines and approaching 1 on January 24. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICES?: This study supports previous findings that COVID-19 has high transmissibility and that implementing comprehensive measures is effective in controlling the COVID-19 outbreak.

Effect of daily average temperature on hand-foot-mouth disease incidence among children under 5 years old in Jingzhou / 中国学校卫生

Objective@#To evaluate the effect of daily temperature on hand-foot-mouth disease (HFMD) in children under 5 years old in Jingzhou city.@*Methods@#HFMD incidence data and meteorological data in Jingzhou city were obtained during 2010 and 2017. Distributed lag non-linear model (DLNM) was utilized to investigate the impact of daily temperature on HFMD incidence among children under 5 years old adjusting for potential confounders of other meteorological factors, secular trend, weekdays and holidays.@*Results@#A total of 47 525 cases were reported during 2010 to 2017, of which the ratio of male to female was 1.52. Children under 1 year old, 1-<3 years old, 3-5 years old accounted for 9.72%, 62.10%, and 28.18% of the total cases, respectively. Children cared at home and children care in kindergarten accounted for 73.29% and 26.71% of the total cases, respectively. The relationship between the temperature and the daily cases of HFMD in children under five years old was a ‘M’ pattern. Compared with a reference temperature (the 50 th percentile of average temperature during the study period, P 50), the maximum value of effect at 8.21 ℃ and 25.81 ℃ were 1.53(95%CI=1.33-1.76) and 1.47(95%CI=1.31-1.65). Higher temperatures (such as 25.81 ℃ in this paper) showed a long lag effect on the HFMD incidence compared with lower temperatures (such as 8.21 ℃). Subgroup analyses indicated that children aged 3-5 years (children who attended daycare) were more vulnerable to the effects of temperature changes on HFMD than those under 1 year old and 1-<3-year-old (cared at home).@*Conclusion@#The temperature has a significant impact on the HFMD incidence among children under five years old in Jingzhou. Daycare centers is the key place for prevention and control of HFMD.