Lithium-ion capacitors(LICs)are becoming important electrochemical energy storage systems due to their great potential to bridge the gap between supercapacitors and lithium-ion batteries.However,capacity lopsidedness ...Lithium-ion capacitors(LICs)are becoming important electrochemical energy storage systems due to their great potential to bridge the gap between supercapacitors and lithium-ion batteries.However,capacity lopsidedness and low output voltage greatly hinder the realization of high-energy-density LICs.Herein,a strategy of balancing capacity towards fastest dynamics is proposed to enable high-voltage LICs.Through electrochemical prelithiation of Nb_(2)C to be 1.1 V with 165 mAh g^(-1),Nb_(2)C//LiFePO_(4) LICs show a broadened potential window from 3.0 to 4.2 V and an according high energy density of 420 Wh kg^(-1).Moreover,the underlying mechanism between prelithiation and high voltage is disclosed by electrochemical dynamic analysis.Prelithiation declines the Nb_(2)C anode potential that facilitates electron transmission in the interlayer of two-dimensional Nb_(2)C MXene.This effect induces small drive force for Li^(+)ions deposition and hence weakens the repulsive force from adsorbed ions on the electrode surface.Benefiting from even more Li^(+)ions deposition,a higher voltage is eventually delivered.In addition,prelithiation significantly increases Coulomb efficiency of the 1st cycle from 74%to 90%,which is crucial to commercial application of LICs.展开更多
Globomycin is a cyclic lipodepsipeptide originally isolated from several Streptomyces species which displays strong and selective antibacterial activity against Gram-negative pathogens.Its mode of action is based on t...Globomycin is a cyclic lipodepsipeptide originally isolated from several Streptomyces species which displays strong and selective antibacterial activity against Gram-negative pathogens.Its mode of action is based on the competitive inhibition of the lipoprotein signal peptidase II(LspA),which is absent in eukaryotes and considered an attractive target for the development of new antibiotics.Despite its interesting biological properties,the gene cluster encoding its biosynthesis has not yet been identified.In this study we employed a genome-mining approach in the globomycin-producing Streptomyces sp.CA-278952 to identify a candidate gene cluster responsible for its biosynthesis.A null mutant was constructed using CRISPR base editing where production was abolished,strongly suggesting its involvement in the biosynthesis.The putative gene cluster was then cloned and heterologously expressed in Streptomyces albus J1074 and Streptomyces coelicolor M1146,therefore unambigu-ously linking globomycin and its biosynthetic gene cluster.Our work paves the way for the biosynthesis of new globomycin derivatives with improved pharmacological properties.展开更多
基金financial supported from the National Natural Science Foundation of China (Nos. 51977185 and 51972277)the financial supported from Southwest Jiaotong University Science and Technology Rising Star Program (No. 2682021CG021)
文摘Lithium-ion capacitors(LICs)are becoming important electrochemical energy storage systems due to their great potential to bridge the gap between supercapacitors and lithium-ion batteries.However,capacity lopsidedness and low output voltage greatly hinder the realization of high-energy-density LICs.Herein,a strategy of balancing capacity towards fastest dynamics is proposed to enable high-voltage LICs.Through electrochemical prelithiation of Nb_(2)C to be 1.1 V with 165 mAh g^(-1),Nb_(2)C//LiFePO_(4) LICs show a broadened potential window from 3.0 to 4.2 V and an according high energy density of 420 Wh kg^(-1).Moreover,the underlying mechanism between prelithiation and high voltage is disclosed by electrochemical dynamic analysis.Prelithiation declines the Nb_(2)C anode potential that facilitates electron transmission in the interlayer of two-dimensional Nb_(2)C MXene.This effect induces small drive force for Li^(+)ions deposition and hence weakens the repulsive force from adsorbed ions on the electrode surface.Benefiting from even more Li^(+)ions deposition,a higher voltage is eventually delivered.In addition,prelithiation significantly increases Coulomb efficiency of the 1st cycle from 74%to 90%,which is crucial to commercial application of LICs.
基金funded by grants of the Novo Nordisk Foundation,Denmark(NNF16OC0021746 to O.G.,T.W.,NNF20CC0035580 to T.W.).
文摘Globomycin is a cyclic lipodepsipeptide originally isolated from several Streptomyces species which displays strong and selective antibacterial activity against Gram-negative pathogens.Its mode of action is based on the competitive inhibition of the lipoprotein signal peptidase II(LspA),which is absent in eukaryotes and considered an attractive target for the development of new antibiotics.Despite its interesting biological properties,the gene cluster encoding its biosynthesis has not yet been identified.In this study we employed a genome-mining approach in the globomycin-producing Streptomyces sp.CA-278952 to identify a candidate gene cluster responsible for its biosynthesis.A null mutant was constructed using CRISPR base editing where production was abolished,strongly suggesting its involvement in the biosynthesis.The putative gene cluster was then cloned and heterologously expressed in Streptomyces albus J1074 and Streptomyces coelicolor M1146,therefore unambigu-ously linking globomycin and its biosynthetic gene cluster.Our work paves the way for the biosynthesis of new globomycin derivatives with improved pharmacological properties.
