Co-Cu-based catalysts are widely applied in higher alcohol synthesis (HAS) from synthesis gas. Although the nature of the active sites is still not fully understood, the formation of Co2C under HAS conditions seems to...Co-Cu-based catalysts are widely applied in higher alcohol synthesis (HAS) from synthesis gas. Although the nature of the active sites is still not fully understood, the formation of Co2C under HAS conditions seems to play a major role. A CO pretreatment procedure was developed allowing a systematic investigation of the influence of cobalt carbidization on the structural properties and catalytic performance of the catalysts. By exposing the catalyst to a CO-containing atmosphere prior to HAS, Co enrichment of the catalyst surface occurred followed by carbide formation. This surface modification decreased the formation of hydrocarbons and enhanced the formation of C2+OH. The catalyst pretreated with CO at 20 bar achieved the highest selectivity to ethanol and the lowest hydrocarbon selectivity.展开更多
Many studies have shown the efficacy of phage therapy in reducing gastrointestinal pathogens.However,it is unclear whether phages can successfully colonize the gut when administered in an adequate amount for a long ti...Many studies have shown the efficacy of phage therapy in reducing gastrointestinal pathogens.However,it is unclear whether phages can successfully colonize the gut when administered in an adequate amount for a long time.About 1×10^(8)PFU/mL of purified lytic phage PA13076 or temperate phage BP96115 were fed daily to mice via drinking water over 31 days,to elucidate the distribution of phages in the gastrointestinal tract.At day 16 and 31,six different segments of the gastrointestinal tract with their contents,including stomach,duodenum,jejunum,ileum,cecum,colon,and fresh feces,were aseptically collected.The phage titers were determined using the double-layered plate method with S.Enteritidis ATCC 13076 or S.Pullorum SPu-109 used as host cells.The results indicated that a small portion of administered phages survived exposure to gastric acid and entered the intestinal tract.The prevalence of phages in the gastrointestinal tract was lower than 1%of the primary phage count.Highest phage titers were detected in the cecum with 10^(4)~10^(5)PFU/g,and most of the phages were eliminated from the body via feces with 10^(6)PFU/g.On day 16 and day 31,the same level of phage titers in different segments of the gastrointestinal tract indicated that the colonization of phages had reached saturation at day 16.These results demonstrate transient phage carriage and low-level colonization of orally administrated lytic and temperate gut phages in mice.展开更多
基金funded by the Federal Ministry of Education and Research(Bundesministerium für Bildung und Forschung,BMBF,Verbundvorhaben Carbon2Chem■,FKZ:03EK3041)
文摘Co-Cu-based catalysts are widely applied in higher alcohol synthesis (HAS) from synthesis gas. Although the nature of the active sites is still not fully understood, the formation of Co2C under HAS conditions seems to play a major role. A CO pretreatment procedure was developed allowing a systematic investigation of the influence of cobalt carbidization on the structural properties and catalytic performance of the catalysts. By exposing the catalyst to a CO-containing atmosphere prior to HAS, Co enrichment of the catalyst surface occurred followed by carbide formation. This surface modification decreased the formation of hydrocarbons and enhanced the formation of C2+OH. The catalyst pretreated with CO at 20 bar achieved the highest selectivity to ethanol and the lowest hydrocarbon selectivity.
基金supported by the National Natural Science Foundation of China(NSFC 31701725 and 31950410562)the National Key R&D Program of China(No.2018YEE0101900).
文摘Many studies have shown the efficacy of phage therapy in reducing gastrointestinal pathogens.However,it is unclear whether phages can successfully colonize the gut when administered in an adequate amount for a long time.About 1×10^(8)PFU/mL of purified lytic phage PA13076 or temperate phage BP96115 were fed daily to mice via drinking water over 31 days,to elucidate the distribution of phages in the gastrointestinal tract.At day 16 and 31,six different segments of the gastrointestinal tract with their contents,including stomach,duodenum,jejunum,ileum,cecum,colon,and fresh feces,were aseptically collected.The phage titers were determined using the double-layered plate method with S.Enteritidis ATCC 13076 or S.Pullorum SPu-109 used as host cells.The results indicated that a small portion of administered phages survived exposure to gastric acid and entered the intestinal tract.The prevalence of phages in the gastrointestinal tract was lower than 1%of the primary phage count.Highest phage titers were detected in the cecum with 10^(4)~10^(5)PFU/g,and most of the phages were eliminated from the body via feces with 10^(6)PFU/g.On day 16 and day 31,the same level of phage titers in different segments of the gastrointestinal tract indicated that the colonization of phages had reached saturation at day 16.These results demonstrate transient phage carriage and low-level colonization of orally administrated lytic and temperate gut phages in mice.
