Highlights d Structures of SARS-CoV-2 RNA polymerase in complexes with RNA revealed d Conformational changes in nsp8 and its interaction with the exiting RNA are observed d Incorporation and delayed-chain-termination mechanism of remdesivir is elucidated d Transition model from primase complex to polymerase complex is proposed

We report a 3.5-angstrom-resolution cryo–electron microscopy structure of a respiratory supercomplex isolated fromMycobacterium smegmatis.It comprises a complex III dimer flanked on either side by individual complex IV subunits. Complex III and IV associate so that electrons can be transferred from quinol in complex III to the oxygen reduction center in complex IV by way of a bridging cytochrome subunit. We observed a superoxide dismutase-like subunit at the periplasmic face, which may be responsible for detoxification of superoxide formed by complex III. The structure reveals features of an established drug target and provides a foundation for the development of treatments for human tuberculosis.

A series of stable heterometallic Fe2M cluster‐based MOFs (NNU‐31‐M, M=Co, Ni, Zn) photocatalysts are presented. They can achieve the overall conversion of CO2 and H2O into HCOOH and O2 without the assistance of additional sacrificial agent and photosensitizer. The heterometallic cluster units and photosensitive ligands excited by visible light generate separated electrons and holes. Then, low‐valent metal M accepts electrons to reduce CO2, and high‐valent Fe uses holes to oxidize H2O. This is the first MOF photocatalyst system to finish artificial photosynthetic full reaction. It is noted that NNU‐31‐Zn exhibits the highest HCOOH yield of 26.3 μmol g−1 h−1 (selectivity of ca. 100 %). Furthermore, the DFT calculations based on crystal structures demonstrate the photocatalytic reaction mechanism. This work proposes a new strategy for how to design crystalline photocatalyst to realize artificial photosynthetic overall reaction.

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The macro- and microstructural evolution of water swollen and ethanol swollen regenerated cellulose gel beads have been determined during drying by optical microscopy combined with analytical balance measurements, small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering (WAXS). Two characteristic length scales, which are related to the molecular dimension of cellulose monomer and elongated aggregates of these monomers, could be identified for both types of beads by SAXS. For ethanol swollen beads, only small changes to the structures were detected in both the SAXS and WAXS measurements during the entire drying process. However, the drying of cellulose from water follows a more complex process when compared to drying from ethanol. As water swollen beads dried, they went through a structural transition where elongated structures changed to spherical structures and their dimensions increased from 3.6 to 13.5 nm. After complete drying from water, the nanostructures were characterized as a combination of rodlike structures with an approximate size of cellulose monomers (0.5 nm), and spherical aggregates (13.5 nm) without any indication of heterogeneous meso- or microporosity. In addition, WAXS shows that cellulose II hydrate structure appears and transforms to cellulose II during water evaporation, however it is not possible to determine the degree of crystallinity of the beads from the present measurements. This work sheds lights on the structural changes that occur within regenerated cellulose materials during drying and can aid in the design and application of cellulosic materials as fibers, adhesives, and membranes.

The design of a powerful heterojunction structure and the study of the interfacial charge migration pathway at the atomic level are essential to mitigate the photocorrosion and recombination of electron–hole pairs of CdS in photocatalytic hydrogen evolution (PHE). A temperature-induced self-assembly strategy has been proposed for the syntheses of Prussian blue analogue (PBA)/CdS nanocomposites with beaded structure. The specially designed structure had evenly exposed CdS which can efficiently harvest visible light and inhibit photocorrosion; meanwhile, PBA with a large cavity provided channels for mass transfer and photocatalytic reaction centers. Remarkably, PB-Co/CdS-LT-3 exhibits a PHE rate of 57 228 μmol h –1 g –1 , far exceeding that of CdS or PB-Co and comparable to those of most reported crystalline porous material-based photocatalysts. The high performances are associated with efficient charge migration from CdS to PB-Co through CN-Cd electron bridges, as revealed by the DFT calculations. This work sheds light on the exploration of heterostructure materials in efficient PHE.

On the basis of the Gibbs free energy (GFE) model of Janus, core−shell, and alloyed structures of Ag−Cu and Ag−Au nanoparticles, the structural stability and size-composition phase diagram are obtained. For phase segregated structure, small size and low temperature are more beneficial at fixed composition. If the temperature is fixed, the segregated phase is favored at small size and low composition. The lowest critical size to phase segregation is 6 nm for Ag−Cu NPs and 4.5 nm for Ag−Au NPs at 400 K and Ag atom fraction of approximately 50%, and raising the temperature reduces the critical size. For Ag−Cu phase diagram, it is found that the core size is dominated by the transformation between Janus and core−shell structure. When the core is sufficient large, the Ag−Cu NPs will keep the core−shell structure. As the core size gets smaller, the core location will be moved from center to off-center until it forms quasi-Janus or Janus NPs. However, for the Ag−Au phase diagram, there is no Janus structure at large scale of composition.

Solid electrolytes have attracted considerable interest in rechargeable batteries because of their potential high safety, inhibition of electrode dissolution, and large electrochemical window. However, their development in some new battery concepts such as room-temperature halide ion batteries has been scarce. Herein, we develop the inorganic halide perovskite of CsSnCl3 prepared by mechanical milling and subsequent mild heat treatment as the potential solid electrolyte for chloride ion batteries (CIB). Benefiting from its high structural stability against a phase transformation to monoclinic structure at room temperature, the as-prepared cubic CsSnCl3 achieves an impressive electrochemical performance with the highest ionic conductivity of 3.6 × 10–4 S cm–1 and a large electrochemical window of about 6.1 V at 298 K. These values are much higher than 1.2 × 10–5 S cm–1 and 4.25 V of the previously reported solid polymer electrolyte for CIBs. Importantly, the chloride ion transfer of the as-prepared CsSnCl3 electrolyte is demonstrated by employing the electrode couples of SnCl2/Sn and BiCl3/Bi.