Selective conversion of renewable sources is necessary for developing energy generation technology and protecting the environment. Herein, this work reports a one-step controllable synthesis of trimetallic NiCoFe-layered double hydroxides (NiCoFe-LDHs) nanosheets (1.36 nm) for both an efficient oxygen evolution reaction (OER) and highly selective oxidation of biomass-derived 5-hydroxymethylfurfural (HMFOR) into value-added 2,5-furandicarboxylic acid (FDCA). For comparison, two sets of bimetallic NiCo- and NiFe-LDHs were similarly synthesized and evaluated. In the OER process, the optimal NiCoFe-LDHs nanosheets exhibited the lowest necessary overpotential (288 mV) to reach 10 mA cm–2 and the smallest Tafel slope of 92 mV dec–1 compared with NiCo-LDHs (347 mV, 115 mV dec–1) and NiFe-LDHs (303 mV, 108 mV dec–1). The performance was also superior to most previously reported LDHs catalysts. Additionally, NiCoFe-LDHs nanosheets exhibited a much smaller charge transfer resistance (Rct) of 1.0 Ω and a larger C dl value of 2.62 mF cm–2 compared with NiCo-LDHs (2.1 Ω, 1.94 mF cm–2) and NiFe-LDHs (1.4 Ω, 2.22 mF cm–2), indicating fast catalytic kinetics. Furthermore, the NiCoFe-LDHs nanosheets possessed excellent durability over 10 h, much better than that of NiCo- and NiFe-LDHs. NiCoFe-LDHs catalysts also exhibited high performance in the oxidation of 5-hydroxymethylfurfural (HMF) to FDCA, which is a key precursor for the sustainable synthesis of polymers (e.g., polyethylene 2,5-furandicarboxylate (PEF)). An ultralow overpotential of 280 mV was required to achieve 20 mA cm–2, nearly 120 mV less than the activity in pure 1.0 M NaOH. The reaction intermediates and products were qualified by liquid chromatography–mass spectroscopy system (LC-MS) and LC, where 95.5% conversion of HMF and 84.9% yield of FDCA were obtained in 1 h. The reaction kinetics and possible pathways were further investigated. As a unique report utilizing trimetallic LDHs catalysts for OER and HMFOR, this study provides a promising perspective for energy conversion and electrocatalytic processing of biomass-derived monomers.

The association of Zika virus (ZIKV) infections with microcephaly and neurological diseases has highlighted an emerging public health concern. Here, we report the crystal structure of the full‐length ZIKV nonstructural protein 1 (NS1), a major host‐interaction molecule that functions in flaviviral replication, pathogenesis, and immune evasion. Of note, a long intertwined loop is observed in the wing domain of ZIKV NS1, and forms a hydrophobic “spike”, which can contribute to cellular membrane association. For different flaviviruses, the amino acid sequences of the “spike” are variable but their common characteristic is either hydrophobic or positively charged, which is a beneficial feature for membrane binding. Comparative studies with West Nile and Dengue virus NS1 structures reveal conserved features, but diversified electrostatic characteristics on both inner and outer faces. Our results suggest different mechanisms of flavivirus pathogenesis and should be considered during the development of diagnostic tools.

We re-examine the classifications of supernovae (SNe) presented in the Lick Observatory Supernova Search (LOSS) volume-limited sample with a focus on the stripped-envelope SNe. The LOSS volumelimited sample, presented by Leaman et al. (2011) andLi et al. (2011b), was calibrated to provide meaningful measurements of SN rates in the local universe; the results presented therein continue to be used for comparisons to theoretical and modeling efforts. Many of the objects from the LOSS sample were originally classified based upon only a small subset of the data now available, however, and recent studies have both updated some subtype distinctions and improved our ability to perform robust classifications, especially for stripped-envelope SNe. We re-examine the spectroscopic classifications of all events in the LOSS volume-limited sample (180 SNe and SN impostors) and update them if necessary. We discuss the populations of rare objects in our sample including broad-lined Type Ic SNe, Ca-rich SNe, SN 1987A-like events (we identify SN 2005io as SN 1987A-like here for the first time), and peculiar subtypes. The relative fractions of Type Ia SNe, Type II SNe, and stripped-envelope SNe in the local universe are not affected, but those of some subtypes are. Most significantly, after discussing the often unclear boundary between SNe Ib and Ic when only noisy spectra are available, we find a higher SN Ib fraction and a lower SN Ic fraction than calculated by Li et al. (2011b): spectroscopically normal SNe Ib occur in the local universe 1.7 ± 0.9 times more often than do normal SNe Ic.