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1.
J Am Chem Soc ; 144(27): 12339-12346, 2022 07 13.
Article in English | MEDLINE | ID: mdl-35771208

ABSTRACT

N-Methylformamide, HC(O)NH(CH3), is the smallest amide detected in the interstellar medium that can exist as cis and trans isomers. We performed reactions of H atoms with trans-NMF in solid para-hydrogen at 3.3 K and found that the cis-NMF isomer, which has higher energy, increased continuously in darkness, demonstrating a previously overlooked and seemingly unlikely isomerization of prebiotic molecules through H-atom tunneling reactions in the absence of light. Infrared spectra of radical intermediates trans-•C(O)NH(CH3) and trans-HC(O)NH(•CH2) were identified. Further H addition and H abstraction enhanced the formation of CH3NCO, HNCO, and CH2NH in the H-rich experiments. These results indicate that, unlike the dual cycle of H-abstraction and H-addition channels chemically linking formamide and HNCO, the H addition to CH3NCO produced only cis-radicals that led to cis-NMF. Furthermore, H-atom-induced fragmentation by breaking the C-C bond provides links between NMF and HCNO/CH2NH. These endothermic isomerization/decomposition reactions become possible through the coupling with H + H → H2.


Subject(s)
Formamides , Hydrogen , Darkness , Formamides/chemistry , Hydrogen/chemistry , Isomerism
2.
Transbound Emerg Dis ; 69(1): 57-65, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34240562

ABSTRACT

Research has shown that feed and feed ingredients can be one of the potential routes of transmitting viral pathogens into swine farms. In this short communication, we report two cases of Porcine Epidemic Diarrhea (PED) in two sow farms located in eastern China. Immediately after the outbreaks, extensive sampling and testing for genetic materials of PEDV was carried out on farms, and at the feed mill, in an effort to identify possible sources of infection based on field observations of local area viral spread and interventions already implemented to lower risk of this spread. Samples collected from personnel or supplies entering the farms were inspected and proved as low risk factors. In contrast, feed and feed ingredient samples collected at the on-farm feed bins, and at the feed mill, tested positive for PEDV RNA. Based on these data, multiple interventions to lower viral spread via feed were implemented including (1) simplification of diet formulation excluding high-risk ingredients, (2) extension of thermal treatment during pellet conditioning and (3) maximising feed quarantine on farm up to 7 days from feed delivery to consumption. Collectively, these interventions appeared to have a positive effect as the prevalence of PED-related disease and the number of PEDV-positive feed or feed ingredient samples decreased considerably following implementation.


Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Animals , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Diarrhea/epidemiology , Diarrhea/veterinary , Disease Outbreaks , Female , Prevalence , Swine , Swine Diseases/epidemiology , Swine Diseases/prevention & control
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