No abstract

The oxidation of 5-hydroxylmethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a sustainable and promising route to bioderived aromatic polyesters. So far, the design of catalyst has been restricted by the unclear working mechanism, and thus most of the supported noble metal catalysts cannot provide a remarkable reaction rate under atmospheric pressures and room temperature. Here we report a new mechanistic insight into the structure–performance correlation of graphene-supported Pd catalysts. It is demonstrated that a new kind of highly porous nitrogen- and phosphorus-codoped graphene sheets (HPGSs) will enhance the fraction of surface Pd2+ species, which plays a determining role to reduce the activation energies of both HMF conversion and FDCA formation. Such a support effect may assist in developing highly active catalysts for FDCA synthesis under mild conditions.

The omicron variant is thought to cause less olfactory dysfunction than previous variants of SARS-CoV-2, but the reported prevalence differs greatly between populations and studies. Our systematic review and meta-analysis provide information regarding regional differences in prevalence as well as an estimate of the global prevalence of olfactory dysfunction based on 62 studies reporting information on 626,035 patients infected with the omicron variant. Our estimate of the omicron-induced prevalence of olfactory dysfunction in populations of European ancestry is 11.7%, while it is significantly lower in all other populations, ranging between 1.9% and 4.9%. When ethnic differences and population sizes are considered, the global prevalence of omicron-induced olfactory dysfunction in adults is estimated to be 3.7%. Omicron’s effect on olfaction is twofold to tenfold lower than that of the alpha or delta variants according to previous meta-analyses and our analysis of studies that directly compared the prevalence of olfactory dysfunction between omicron and previous variants. The profile of the prevalence differences between ethnicities mirrors the results of a recent genome-wide association study that connected a gene locus encoding an odorant-metabolizing enzyme, UDP glycosyltransferase, to the extent of COVID-19-related loss of smell. Our analysis is consistent with the hypothesis that this enzyme contributes to the observed population differences.

Icariin (ICA) is a bioactive flavonoid extracted from Epimedium brevicornum Maxim and exhibits a variety of pharmacological activities including antiinflammatory and antioxidant effects. Recently, icariin has shown renoprotective role by inhibiting pathological matrix. However, the underlying mechanisms of the efficacy remain unknown. This study aimed to determine the effects of icariin on renal fibrosis and explore its molecular mechanisms. Chronic kidney disease (CKD) was induced in rats with 5/6 ablation and infarction (A/I) operation. Four weeks later, rats were treated with vehicle or 20 mg/kg (low dose) or 40 mg/kg (high dose) of icariin by daily gavage. Furthermore, to further elucidate the effect mechanisms of icariin, in vitro, NRK‐49F cells stimulated by 8 ng/ml IL‐1β were treated with icariin in the presence or absence of SB431542 or the neutralizing antibody of transforming growth factor‐β (TGF‐β) for 24 h. We showed that icariin treatment for 8 weeks dose‐dependently improved 5/6 (A/I)‐induced kidney injury and fibrosis, and blocked the release of inflammatory cytokine IL‐1β. In vitro, icariin inhibited IL‐1β/TGF‐β‐mediated activation of renal fibroblasts. In summary, anti‐fibrotic effects of icariin were interconnected with the inhibition of renal fibroblast activation caused by IL‐1β/TGF‐β signaling.