1. Rapid preparation of gaseous methanediol (CH2(OH)2)
Yi-Fang Chen, Li-Kang Chu Chem Commun (Camb). 2022 Mar 29;58(26):4208-4210. doi: 10.1039/d2cc00964a.
The simplest geminal diol CH2(OH)2 serves as an important precursor to form atmospheric formic acid. CH2(OH)2 vapour can be generated by the evaporation of an aqueous formaldehyde solution, prepared by dissolving paraformaldehyde under reflux. Its rovibrational feature at 980-1100 cm-1 is consistent with the simulation and free of the intense interferences of H2O and CH2O.
2. NH2OH Disproportionation Mediated by Anaerobic Ammonium-oxidizing (Anammox) Bacteria
Mamoru Oshiki, Lin Gao, Lei Zhang, Satoshi Okabe Microbes Environ. 2022;37(2):ME21092. doi: 10.1264/jsme2.ME21092.
Anammox bacteria produce N2 gas by oxidizing NH4+ with NO2-, and hydroxylamine (NH2OH) is a potential intermediate of the anammox process. N2 gas production occurs when anammox bacteria are incubated with NH2OH only, indicating their capacity for NH2OH disproportionation with NH2OH serving as both the electron donor and acceptor. Limited information is currently available on NH2OH disproportionation by anammox bacteria; therefore, the stoichiometry of anammox bacterial NH2OH disproportionation was examined in the present study using 15N-tracing techniques. The anammox bacteria, Brocadia sinica, Jettenia caeni, and Scalindua sp. were incubated with the addition of 15NH2OH, and the production of 15N-labeled nitrogenous compounds was assessed. The anammox bacteria tested performed NH2OH disproportionation and produced 15-15N2 gas and NH4+ as reaction products. The addition of acetylene, an inhibitor of the anammox process, reduced the activity of NH2OH disproportionation, but not completely. The growth of B. sinica by NH2OH disproportionation (-240.3 kJ mol NH2OH-1 under standard conditions) was also tested in 3 up-flow column anammox reactors fed with 1) 0.7 mM NH2OH only, 2) 0.7 mM NH2OH and 0.5 mM NH4+, and 3) 0.7 mM NH2OH and 0.5 mM NO2-. NH2OH consumption activities were markedly reduced after 7 d of operation, indicating that B. sinica was unable to maintain its activity or biomass by NH2OH disproportionation.
3. TiO2/Cu2(OH)2CO3 nanocomposite as efficient antimicrobials for inactivation of crop pathogens in agriculture
Bingkun Liu, Lilong Mu, Jingtao Zhang, Xiaole Han, Hengzhen Shi Mater Sci Eng C Mater Biol Appl. 2020 Feb;107:110344. doi: 10.1016/j.msec.2019.110344. Epub 2019 Oct 23.
TiO2/Cu2(OH)2CO3 nanocomposite were synthesized via a simple in-situ precipitation process, which was applied as efficient antimicrobials for the inactivation of Escherichia coli (E. coli) and Fusarium graminearum (F. graminearum) under simulated solar light. With optimum Cu2(OH)2CO3 amount of 1.8 mol%, the TiO2/Cu2(OH)2CO3 nanocomposite presented the highest antimicrobial activities against E. coli and F. graminearum, and achieved complete inactivation in 80 min, which was far better than that of bare TiO2. The boosted photocatalytic disinfection efficiency was ascribed to the increased light harvesting and efficient charge transfer and separation in the TiO2/Cu2(OH)2CO3 nanocomposite, which resulted in more efficient generation of ·OH and ·O2- that played important role in the photocatalytic inactivation process. Our work revealed that TiO2/Cu2(OH)2CO3 composite was a promising antimicrobial agent for prevention of pathogenic fungal or bacterial infections in crop protection.
