The SARS-CoV-2 Omicron with increased fitness is spreading rapidly worldwide. Analysis of cryo-EM structures of the Spike (S) from Omicron reveals amino acid substitutions forging interactions that stably maintain an active conformation for receptor recognition. The relatively more compact domain organization confers improved stability and enhances attachment but compromises the efficiency of the viral fusion step. Alterations in local conformation, charge and hydrophobic microenvironments underpin the modulation of the epitopes such that they are not recognized by most NTD- and RBD-antibodies, facilitating viral immune escape. Structure of the Omicron S bound with human ACE2, together with the analysis of sequence conservation in ACE2 binding region of 25 sarbecovirus members as well as heatmaps of the immunogenic sites and their corresponding mutational frequencies sheds light on conserved and structurally restrained regions that can be used for the development of broad-spectrum vaccines and therapeutics.

We reported here a strategy to use a defective nanodiamond-graphene (ND@G) to prepare an atomically dispersed metal catalyst, i.e., in the current case atomically dispersed palladium catalyst which is used for selective hydrogenation of acetylene in the presence of abundant ethylene. The catalyst exhibits remarkable performance for the selective conversion of acetylene to ethylene: high conversion (100%), ethylene selectivity (90%), and good stability. The unique structure of the catalyst (i.e., atomically dispersion of Pd atoms on graphene through Pd–C bond anchoring) blocks the formation of unselective subsurface hydrogen species and ensures the facile desorption of ethylene against the overhydrogenation to undesired ethane, which is the key for the outstanding selectivity of the catalyst.