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2D functional porous frameworks offer a platform for studying the structure–activity relationships during electrocatalytic CO2 reduction reaction (CO2RR). Yet challenges still exist to breakthrough key limitations on site configuration (typical M−O4 or M−N4 units) and product selectivity (common CO2‐to‐CO conversion). Herein, a novel 2D metal–organic framework (MOF) with planar asymmetric N/O mixed coordinated Cu−N1O3 unit is constructed, labeled as BIT‐119. When applied to CO2RR, BIT‐119 could reach a CO2‐to‐C2 conversion with C2 partial current density ranging from 36.9 to 165.0 mA cm−2 in flow cell. Compared to the typical symmetric Cu−O4 units, asymmetric Cu−N1O3 units lead to the re‐distribution of local electron structure, regulating the adsorption strength of several key adsorbates and the following catalytic selectivity. From experimental and theoretical analyses, Cu−N1O3 sites could simultaneously couple the atop‐type (on Cu site) and bridge‐type (on Cu−N site) adsorption of *C1 species to reach the CO2‐to‐C2 conversion. This work broadens the feasible C−C coupling mechanism on 2D functional porous frameworks. [ABSTRACT FROM AUTHOR]

In this report, we developed an efficient one-pot method for the synthesis of 3-phenyl-1-(phenylthio)imidazo[1,5-a]pyridine analogs starting from 2-aminomethylpyridines, benzaldehydes, and sodium benzenesulfinates, which constructed C-N and C-S bonds simultaneously. The method features mild reaction conditions, a wide range of substrates, high atom utilization, and convenient and easily accessible starting materials. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC) activation and antigen presentation are critical for efficient priming of T cell responses. Here, we study how lentiviral vectors (LVs) deliver antigen and activate DCs to generate T cell immunization in vivo. We report that antigenic proteins delivered in vector particles via pseudotransduction were sufficient to stimulate an antigen-specific immune response. The delivery of the viral genome encoding the antigen increased the magnitude of this response in vivo but was irrelevant in vitro. Activation of DCs by LVs was independent of MyD88, TRIF, and MAVS, ruling out an involvement of Toll-like receptor or RIG-I-like receptor signaling. Cellular DNA packaged in LV preparations induced DC activation by the host STING (stimulator of interferon genes) and cGAS (cyclic guanosine monophosphate-adenosine monophosphate synthase) pathway. Envelope-mediated viral fusion also activated DCs in a phosphoinositide 3-kinase-dependent but STING-independent process. Pseudotransduction, transduction, viral fusion, and delivery of cellular DNA collaborate to make the DC-targeted LV preparation an effective immunogen.

Electrocatalytic CO2 to multi‐carbon products is an attractive strategy to achieve a carbon‐neutral energy cycle. Single‐atom catalysts (SACs) that achieve the C2 selectivity always have low metal loading and inevitably undergo in situ reversible/irreversible metallic agglomerations under working conditions. Herein, a high‐density Cu SA anchored F, O, N co‐doped carbon composites (CuFONC) with a stable CuN2O1 configuration is provided, which can reach a remarkable C2 selectivity of ≈80.5% in Faradaic efficiency at −1.3 V versus RHE. In situ/ex situ experimental characterization and density functional theory (DFT) calculations verified that the excellent stability of CuN2O1 during the CO2RR process can be attributed to F/O co‐derived regulation for CuFONC. Remarkably, as confirmed by DFT, it is atomic Cu sites and the adjacent bonded N motifs in CuFONC that act as the adsorption sites for CO* during the C─C coupling process. This work brings a prospective on designing novel but stable atomic Cu coordination for electrolytic CO2‐to‐C2 pathway. [ABSTRACT FROM AUTHOR]

Single atomic catalysts (SACs) offer a superior platform for studying the structure–activity relationships during electrocatalytic CO2 reduction reaction (CO2RR). Yet challenges still exist to obtain well‐defined and novel site configuration owing to the uncertainty of functional framework‐derived SACs through calcination. Herein, a novel Bi−N2O2 site supported on the (1 1 0) plane of hydrogen‐bonded organic framework (HOF) is reported directly for CO2RR. In flow cell, the target catalyst Bi1‐HOF maintains a faradaic efficiency (FE) HCOOH of over 90 % at a wide potential window of 1.4 V. The corresponding partial current density ranges from 113.3 to 747.0 mA cm−2. And, Bi1‐HOF exhibits a long‐term stability of over 30 h under a successive potential‐step test with a current density of 100–400 mA cm−2. Density function theory (DFT) calculations illustrate that the novel Bi−N2O2 site supported on the (1 1 0) plane of HOF effectively induces the oriented electron transfer from Bi center to CO2 molecule, reaching an enhanced CO2 activation and reduction. Besides, this study offers a versatile method to reach series of M−N2O2 sites with regulable metal centers via the same intercalation mechanism, broadening the platform for studying the structure–activity relationships during CO2RR. [ABSTRACT FROM AUTHOR]