Non-structural proteins (nsp) constitute the SARS-CoV-2 replication and transcription complex (RTC) to play a pivotal role in the virus life cycle. Here we determine the atomic structure of a SARS-CoV-2 mini RTC, assembled by viral RNA-dependent RNA polymerase (RdRp, nsp12) with a template-primer RNA, nsp7 and nsp8, and two helicase molecules (nsp13-1 and nsp13-2), by cryo-electron microscopy. Two groups of mini RTCs with different conformations of nsp13-1 are identified. In both of them, nsp13-1 stabilizes overall architecture of the mini RTC by contacting with nsp13-2, which anchors the 5′-extension of RNA template, as well as interacting with nsp7-nsp8-nsp12-RNA. Orientation shifts of nsp13-1 results in its variable interactions with other components in two forms of mini RTC. The mutations on nsp13-1:nsp12 and nsp13-1:nsp13-2 interfaces prohibit the enhancement of helicase activity achieved by mini RTCs. These results provide an insight into how helicase couples with polymerase to facilitate its function in virus replication and transcription.

Purpose – Patient value co-creation represents a key research priority and an essential determinant of health care service outcomes. Yet few studies empirically examine the factors that motivate patients to participate actively in value co-creation. The purpose of this paper is to seek to identify the motivators of such activities in online health communities (OHC) and examine their specific and unique effects. Design/methodology/approach – A netnographic study helps identify the motivators that drive patients’ value co-creation activities in OHCs. The combination of these results with social identity theories suggest the hypotheses; mediation analyses test the hypothesized model with data collected from eight OHCs that address both life-threatening and non-life-threatening illnesses. Findings – The netnographic results show that social identity drives patients’ value co-creation activities. Interactions among OHC members and the cognitive resources of the OHC both contribute to the development of its social identity. Furthermore, benevolence trust, shared vision, and shared language determine how likely an OHC member is to identify with a particular OHC, which further influences his or her value co-creation activities in that OHC. Originality/value – Although value co-creation is critical to the health care sector, few studies examine antecedents of patient value co-creation empirically. This study represents an initial attempt to do so by combining innovative netnographic analyses with mediation analyses.

N-halamine-functionalized silica-polymer core-shell nanoparticles with enhanced antibacterial activity were synthesized through the encapsulation of silica nanoparticles as support with polymeric N-halamine. The as-synthesized nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive x-ray spectrometry (EDX), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR). These N-halamine-functionalized silica-polymer core-shell nanoparticles displayed powerful antibacterial performance against both Gram-positive bacteria and Gram-negative bacteria, and their antibacterial activities have been greatly improved compared with their bulk counterparts. Therefore, these N-halamine-functionalized silica-polymer core-shell nanoparticles have the potential for various significant applications such as in medical devices, healthcare products, water purification systems, hospitals, dental office equipment, food packaging, food storage, household sanitation, etc.

Tunable Cu-BTC mesoporous metal–organic frameworks (mesoMOFs) are prepared conveniently through a template-free strategy under solvothermal conditions. Nanosized microporous Cu-BTC particles pack to form mesopores with sizes that can be controlled (26–72 nm) by simply varying the synthesis temperature. This template-free and controllable strategy can be applied using other organic solvents to obtain mesoMOF materials that possess similar tunable mesopores. Furthermore, the as-synthesized hierarchically porous MOFs materials are demonstrated as the electrocatalysts for oxygen reduction reaction under mild conditions.

No abstract