An overview on metal-related catalysts: metal oxides, nanoporous metals and supported metal nanoparticles on metal organic frameworks and zeolites

Metal nanoparticles(NPs) supported on porous materials have shown great advantages in many catalytic application fields. Supported metal NPs are receiving extensive attention due to their significant contribution in a wide range of current and future applications, and this is arguably one of the fastest growing research fields. In this review, we highlight various types of metal catalysts that possess great potential in several catalytic reactions. The major focus has been on metal oxides, nanoporous metals and metal NPs supported on metal-organic frameworks(MOFs) and zeolites. Special attention has been given to the synthesis strategies and application of the NPs supported on MOFs and zeolites, which are considered highly interesting and rapidly expanding areas in heterogeneous catalysis. Finally, the prospects of these catalysts have been included in the concluding remarks.

Therapeutic strategy targeting host lipolysis limits infection by SARS-CoV-2 and influenza A virus

The biosynthesis of host lipids and/or lipid droplets(LDs)has been studied extensively as a putative therapeutic target in diverse viral infections.However,directly targeting the LD lipolytic catabolism in virus-infected cells has not been widely investigated.Here,we show the linkage of the LD-associated lipase activation to the breakdown of LDs for the generation of free fatty acids(FFAs)at the late stage of diverse RNA viral infections,which represents a broad-spectrum antiviral target.Dysfunction of membrane transporter systems due to virus-induced cell injury results in intracellular malnutrition at the late stage of infection,thereby making the virus more dependent on the FFAs generated from LD storage for viral morphogenesis and as a source of energy.The replication of SARS-CoV-2 and influenza A virus(IAV),which is suppressed by the treatment with LD-associated lipases inhibitors,is rescued by supplementation with FFAs.The administration of lipase inhibitors,either individually or in a combination with virus-targeting drugs,protects mice from lethal IAV infection and mitigates severe lung lesions in SARS-CoV-2-infected hamsters.Moreover,the lipase inhibitors significantly reduce proinflammatory cytokine levels in the lungs of SARS-CoV-2-and IAV-challenged animals,a cause of a cytokine storm important for the critical infection or mortality of COVID-19 and IAV patients.In conclusion,the results reveal that lipase-mediated intracellular LD lipolysis is commonly exploited to facilitate RNA virus replication and furthermore suggest that pharmacological inhibitors of LD-associated lipases could be used to curb current COVID-19-and future pandemic outbreaks of potentially troublesome RNA virus infection in humans.