查看更多>>摘要：As the promising catalysts for the water-gas shift(WGS)reaction,the activity of Au-CeO2 composites is susceptible to the aggregation size and electronic state of Au species.Previous reports were extensively focused on the discrepancy between nonmetallic Au and metallic Au nanoparticles,whereas the understanding of the authentic role of the isolated Au atoms was limited.Herein,we investi-gated the catalytic behavior and structural information over two types of Au/CeO2 catalysts,in which the predominant conjunctions were isolated Au1-CeO2 and Aun-CeO2,respectively.Based on comprehensive characterizations,particularly by in-situ Raman and in-situ DRIFTS,we found that the isolated Au atoms were responsible for enhancing the reducibility of the CeO2 matrix.The CO ad-sorption ability on the isolated Au sites was significantly inferior to clustered Au atoms,especially at relatively high temperatures(＞200 ℃).As a result,the boosted O vacancy on the isolated Au1-CeO2 conjunctions could improve the H2O activation ability for the Au-CeO2 catalysts and demonstrate a comparable activity to the clustered Aun-CeO2 sites.This work might deepen understanding of the catalytic function for the isolated Au1 site within Au/CeO2 systems while catalyzing the WGS reaction.
查看更多>>摘要：5-Methylcytosine(5mC)is a dynamic and reversible epigenetic modification in genomic DNA of higher eukaryotes.It has been well-established that the demethylation of 5mC occurs through the ten-eleven translocation(TET)-mediated oxidation of 5mC fol-lowed by thymine DNA glycosylase(TDG)-initiated base excision repair(BER).Recent findings also have identified an alternative pathway of DNA demethylation.In this pathway,TET enzymes directly oxidize 5mC to form 5-formylcytosine(5fC)or 5-carboxylcytosine(5caC).These modified bases can undergo direct deformylation or decarboxylation,respectively.Additionally,DNA demethylation can also occur through the deamination of 5mC and 5hmC,resulting in the production of thymine and 5-hydroxymethyluracil(5hmU),respectively.Various DNA demethylation pathways possess critical functional implications and roles in biological processes.This Recent Advances article will focus on the studies of mechanisms and biological functions of DNA de-methylation,shedding light on the reversible nature of the epigenetic modification of 5mC.
Tharinee TheerathanagornTanika KessaratikoonHafeez Ur RehmanValerio D'Elia...
652-685页
查看更多>>摘要：Polyhydroxyurethanes(PHUs)have received considerable attention in the last decade as potential alternatives to traditional phos-gene-based polyurethanes(PUs).The development of suitable 5CC(five membered-ring cyclic carbonate)precursors bearing multi-ple carbonate moieties(multi-5CCs)is a key requisite for preparing PHUs by polyaddition reaction with bis-or polyamines.Producing sustainable PHUs from CO2-based five-membered cyclic carbonates(5CCs)obtained from biobased epoxides is a valuable strategy to bridge CO2 utilization and the upcycling of renewable substrates.In this context,while many multi-5CC monomers reported in the literature are oil-based,recent efforts have led to the development of a large variety of multifunctional 5CCs that are produced by the combination of CO2 and renewable resources such as fatty acids and vegetable oils,lignin,terpenes,and sugars.In this work,re-cent crucial advances(2019-2023)on PHUs prepared from bis-and multi-5CCs produced from CO2 and(partially/potentially)bi-obased substrates are reviewed with respect to their synthesis,thermal and mechanical properties,and their recent,emerging ap-plications.
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