Facile Fabrication of Polymer Electrolytes via Lithium Salt-Accelerated Thiol-Michael Addition for Lithium-Ion Batteries

International audiencePolymer electrolyte (PE) that possesses improved thermal and mechanical stability is believed to be by far one of the most promising electrolytes for meeting the safety and performance needs of advanced electrochemical devices. Here, high-performance PEs are fabricated via facile thiol-Michael addition catalyzed by triethylamine in the presence of lithium salts. The lithium salt functions as both an ion source and a co-catalyst, significantly accelerating the thiol-Michael addition reaction. The PEs exhibit a superior thermal decomposition temperature up to 300 °C. Additionally, PEs from the thiol-decorated polyhedral oligomeric silsesquioxane display reversible electrochemical response and stable cycling performance. Our findings based on a self-catalyzed strategy provide a promising direction for rapidly fabricating PEs that meet electrochemical requirements for practical solid polymer batteries

RNAi-mediated knockdown of serine protease inhibitor genes increases the mortality of Plutella xylostella challenged by destruxin A.

Destruxin A is a mycotoxin that is secreted by entomopathogenic fungi which has a broad-spectrum insecticidal effect. Previous transcript and protein profiling analysis showed that destruxin A has significant effects on the expression of serine protease inhibitor genes (serpin-2, 4, 5) in the larvae of Plutella xylostella. In the current study, we aimed to understand the role of serpins under application of destruxin A. We obtained two full-length cDNA sequences of P. xylostella serpins, named serpin-4 and serpin-5, and cloned the serpin-2 gene whose full-length has already been published. Phylogenetic analysis indicated that these two serpin genes were highly clustered with other serpins associated with the immune response in other insects. The temporal and spatial expression of serpin-2, serpin-4 and serpin-5 were determined to be the highest in the fat body and hemolymph of 4th larval stage using qRT-PCR and western blot detection techniques. RNA interference (RNAi) mediated knockdown of P. xylostella serpin genes was carried out by microinjection of double-stranded RNA (dsRNA). The expression levels of serpins decreased significantly after RNAi. Results showed that the depletion of serpins induced cecropins expression, increased phenoloxidase (PO) activity, body melanization and mortality in the larvae of P. xylostella under the same lethal concentration of destruxin A. The superimposed effects of serpins RNAi were similar with the destruxin A treatment upon mortality of P. xylostella larvae. We discovered for the first time that serpins play indispensable role in P. xylostella when challenged by destruxin A and deduced the possible function mechanism of destruxin A. Our findings are conducive to fully understanding the potential insecticidal mechanism of destruxin A and constitute a well-defined potential molecular target for novel insecticides

<i>In Situ</i> Orthogonal Polymerization for Constructing Fast-Charging and Long-Lifespan Li Metal Batteries with Topological Copolymer Electrolytes

Fast-charging Li metal batteries (LMBs) with low cost, high safety, and long lifespan are highly desirable for next-generation energy storage technologies yet have been rarely achieved. Here, we report the in situ fabrication of well-designed blend, block, and bottle-brush solid-state polymer electrolytes (SPEs) integrating poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) and poly(trimethylene carbonate) (PTMC) matrices via Li-catalyzed orthogonal polymerization. Among them, the bottle-brush topological SPEs may display quasi-molecular-scale miscibility between PPEGMA and PTMC, maximize the synergistic coordination of Li+ with ether and carbonate units at the PPEGMA/PTMC interface, and simultaneously exhibit ideal mass transport properties and a broad electrochemical stability window. Further incorporating trifluoroethyl methacrylate (TFEMA) into the bottle-brush SPE allows facile construction of a robust solid electrolyte interphase (SEI). These, together with the fast charge transfer kinetics inherited from the in situ polymerization technique, enable the development of the first example of solid-state polymeric LMB capable of operating steadily at 3C (73% capacity retention after 1000 cycles)

Effect of different serpin knockdown on larval mortality of <i>Plutella xylostella</i>.

<p>Each treatment was injected with 2 µl of a solution containing a total of 5 µg dsRNA. Percentage mortality 24 h after RNAi was calculated. Each value was shown as values ± S.E.M of three independent experiments. Significant differences were indicated with different letters at <i>P</i><0.05.</p

Hemolymph phenoloxidase (PO) activity in serpin silenced larvae of <i>Plutella xylostella</i>.

<p>Hemolymph was collected at 24(dsSerpin-2, dsSerpin-4 and dsSerpin-5). Larvae injected with dsGFP and saline buffer were used as control groups. The PO activity was measured using L-dopa and defined as ΔA₄₉₀ per mg total protein. Each value was shown as values ± S.E.M of three independent experiments. Significant differences were indicated with different letters at <i>P</i><0.05.</p

Melanization of <i>Plutella xylostella</i> treated with destruxin and dsSerpins.

<p>The treatment group was injected with 2 µl of a solution containing 200 µg/ml destruxin A and a total of 5 µg dsRNA. The control treatment was injected with 2 µl of PBS buffer.</p

Detection of the efficiency of RNAi and impact on serpin-2, serpin-4 and serpin-5 mRNA levels by Western Blot (A) and qRT-PCR (B).

<p>The mRNA and protein levels were normalized relative to the β-Actin. The different letters above the columns indicate significant differences in serpins genes expression during <i>P. xylostella</i> development (<i>P</i><0.05). Each point represents mean value ± S.E.M of three independent experiments with three individuals in each replicate. Western Blot analysis visualized by DAB.</p

Multiple alignment of serpin-4 and serpin-5 with other known serpins.

<p>Here serpin-2 (<i>P. xylostella</i>, BAF36820), serpin-4 (<i>Bombyx mori</i>, ACZ81437), serpin-4B (<i>Manduca sexta</i>, AAS68504), serpin-4A (<i>Manduca sexta</i>, AAS68503), serpin-4 (<i>Danaus plexippus</i>, EHJ70588), serpin-5A (<i>Manduca sexta</i>, AAS68507), serpin-4 (<i>Glossina morsitans</i>, AFG28186), serpin-77Ba (<i>Papilio xuthus</i>, BAM10360), serpin-006 (<i>Chilo suppressalis</i>, AFQ01142), serpin-5 (<i>Danaus plexippus</i>, EHJ70286) and serpin-7 (<i>Chilo suppressalis</i>, AFQ01143) are included. The reactive centre loop regions are boxed.</p

Nucleotide sequence (above) and deduced amino acid sequence (below) of the serpin-5 (GenBank accession No. KC505247).

<p>The serpin domain is shadowed. The asterisk (*) indicates the stop codon. Polyadenylation signal is bolded and italicized.</p