COVID‐19 is characterized by dysregulated immune responses, metabolic dysfunction and adverse effects on the function of multiple organs. To understand host responses to COVID‐19 pathophysiology, we combined transcriptomics, proteomics, and metabolomics to identify molecular markers in peripheral blood and plasma samples of 66 COVID‐19‐infected patients experiencing a range of disease severities and 17 healthy controls. A large number of expressed genes, proteins, metabolites, and extracellular RNAs (exRNAs) exhibit strong associations with various clinical parameters. Multiple sets of tissue‐specific proteins and exRNAs varied significantly in both mild and severe patients suggesting a potential impact on tissue function. Chronic activation of neutrophils, IFN‐I signaling, and a high level of inflammatory cytokines were observed in patients with severe disease progression. In contrast, COVID‐19‐infected patients experiencing milder disease symptoms showed robust T‐cell responses. Finally, we identified genes, proteins, and exRNAs as potential biomarkers that might assist in predicting the prognosis of SARS‐CoV‐2 infection. These data refine our understanding of the pathophysiology and clinical progress of COVID‐19.

All-dielectric metamaterials offer great flexibility for controlling light-matter interaction, owing to their strong electric and magnetic resonances with negligible loss at wavelengths above the material bandgap. Here, we propose an all-dielectric asymmetric metasurface structure exhibiting high quality factor and prominent Fano line shape. Over three-orders photoluminescence enhancement is demonstrated in the fabricated all-dielectric metasurface with record-high quality factor of 1011. We find this strong emission enhancement is attributed to the coherent Fano resonances, which originate from the destructive interferences of antisymmetric displacement currents in the asymmetric all-dielectric metasurface. Our observations show a promising approach to realize light emitters based on all-dielectric metasurfaces.

We demonstrate four-wave mixing (FWM) in a 10-μm-radius silicon microring resonator with the assistance of giant nonlinearity of the monolayer graphene. A maximum enhancement of 6.8 dB of conversion efficiency in the silicon-graphene microring (SGM) resonator is observed. A nonlinear propagation model is established and the optical Kerr coefficient of the silicon-graphene hybrid waveguide is three times larger than that of the silicon waveguide.