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New flexible electronic materials and devices have been developed rapidly in nearly a decade from the proposition,discovery,implementation to application.The impact of its strong fold ability and multi-capacity composite structures to technological development and system applications will be enormous.Two mainstream flexible implementation methods were compared:the material-induced flexibility and the structure-induced flexibility.The research progress of domestic and international in related fields was analyzed,including infrastructure,process and potential application directions,and the technical problems faced were summarized.According to the basic research status,flexible electronic devices will have mature application technology innovations achievements in the next few years,new and unprecedented wearable communication,wearable computing,distributed energy,environmental sensing,conformal display devices and devices will be formed.

Listeria monocytogenes is a worrisome food-borne pathogen threatening global food safety. Our previous study proved that lipopeptide brevilaterin B showed efficient antibacterial activity against L. monocytogenes by interacting with the cell membrane. This research further explored the antibacterial mechanism of brevilaterin B against L. monocytogenes at the sub-minimum inhibition concentration via transcriptomic analysis. Brevilaterin B induced growth inhibition rather than direct membrane lysis in L. monocytogenes at the minimum inhibitory concentration. Transcriptomic analysis showed 1779 difference expressed genes, including 895 up-regulated and 884 down-regulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis indicated that brevilaterin B influenced multiple pathways of L. monocytogenes, including peptidoglycan biosynthesis, membrane transport (ATP-binding cassette transports, ion transport), cellular metabolism (amino acid and lipid metabolism), ATP synthesis, and activation of the stress response (quorum sensing and bacterial chemotaxis). In conclusion, brevilaterin B affects gene expression related to biosynthesis, transport and stress response pathways on the membrane of L. monocytogenes. The present work provides the first transcriptomic assessment of the antibacterial mechanism of lipopeptide brevilaterin B at the gene level.

Litopenaeus vannamei protein (LVP) is a high-quality protein. However, its functional properties do not fully meet the needs of food processing. In this study, LVP-xylose conjugates were prepared by conventional wet heat method (GLVP) and ball-milling-assisted wet heat method (GBLVP), respectively. The changes in structure and functional properties of the glycosylated LVP were explored. The findings revealed that ball-milling pretreatment increased the grafting degree to 35.21%. GBLVP had a sparser surface structure and lower particle size than GLVP. FTIR spectra showed that xylose was grafted onto LVP successfully and GBLVP had the lowest α-helix content. Compared with GLVP, GBLVP had a decrease in intrinsic fluorescence intensity and surface hydrophobicity, and an increase in UV absorption intensity. Moreover, GBLVP had higher foaming capacity, solubility and water-holding capacity, and lower allergenicity than GLVP. However, ball-milling pretreatment had a negative impact on the vitro digestibility and oil-holding capacity of GBLVP. In conclusion, ball-milling-assisted treatment of glycosylation could effectively improve the functional properties of LVP, benefiting the broader application of LVP in the food industry.

Abstract Background Brevilaterin A-E, a novel class of multi-component cationic antimicrobial lipopeptides, were biosynthesized by a non-ribosomal peptides synthetase (NRPS) in Brevibacillus laterosporus. However, the antimicrobial abilities of different brevilaterin components varied greatly, and this multi-component form was impeding the scale production of the excellent component, and a little information about the brevilaterin biosynthesis mechanism was available to apply in brevilaterin design modification. In this study, we used an accurate strategy that revealed the reason for producing multi-component was the substrate selectivity of bre2691A protein being not enough specific and pinpointed the key design sites to make the specificity of bre2691A enhanced. Results Bioinformatic analysis revealed that the biocatalytic site of bre2691A, which was an adenylation domain catalyzed and recognized methionine, leucine, valine and isoleucine and thus introduced them into brevilaterins and caused different components (brevilaterin A-E), was consisted of A1 ~ A10 residues named specificity-conferring code. Coupling molecular docking simulations with mutation studies identified A2 and A7 as critical residues, where determined substrate-specificity and impacted activity. The in virto activity assay showed that the A2 mutant (G193A) would lose activity against methionine and have no effect on the other three amino acids, the A7 mutant (G285C) would enhance the catalytic activity against four substrates, especially against leucine at almost a double activity. When the A2 and A7 residues were synchronously mutated, this mutant would be more focused on recognizing leucine. Conclusions An accurate strategy that combined with bioinformatics and site-directed mutation techniques revealed the pivotal site A2 and A7 positions of bre2691A protein that could be used to design and modify brevilaterins, thus further providing a reasonable direction of genetic engineering for Brevibacillus laterosporus. A deeper understanding of the function of crucial residues in the adenylation domain would make it get more accurate and highly efficient design and more fully utilized. Furthermore, it would contribute to biotechnological applications, namely for the large centralized synthesis of antimicrobial peptides, or for the optimization of their production. Graphic Abstract

Flow behaviors of a downstream object can be affected significantly by an upstream object in close proximity. Combined with the neural network algorithms, this concept is used for flow control in this study to optimize the aerodynamic performance of a downstream object. Flow with an oscillating cylinder placed upstream is systematically studied because there are multiple control parameters that influence the flow dynamics around the downstream object. These control parameters are used as the input factors of a back-propagation neural network, and then a revised genetic algorithm is applied to find the optimal set of control parameters. In the current study, we use an airfoil in a low-Reynolds-number flow as an example to investigate the proposed neural network flow optimization concept. The datasets used to train the neural network are from the computational simulation with a previously validated immerse-boundary method to accommodate the motion of the cylinder. The results show that by optimally placing an upstream moving cylinder, it is possible to enhance the aerodynamic performance of the downstream object. Compared to the reference case, the optimized lift/drag ratio of the downstream airfoil can be achieved 2.4 times of its reference value, while maintaining a relatively high lift coefficient.

Bacterial contamination is a primary threat to food safety. Therefore, the persistent development of natural antibacterial agents has become essential work. The present essay attempts to establish a systematic antibacterial activity database to instruct the food application of brevilaterins, promising antibacterial lipopeptides from Brevibacillus laterosporus S62-9. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were systematically collected from 43 species of standard bacteria and 140 strains of isolated bacteria (food spoilage bacteria and antibiotic-resistant bacteria) using a broth dilution method. The results showed that brevilaterins performed a broad-spectrum inhibitory (0.5~128 μg/mL) and bactericidal activity (1~256 μg/mL), especially efficient against Gram-positive bacteria and spoilage bacteria from grain products. Moreover, brevilaterins not only inhibit and kill multiple antibiotic-resistant bacteria but do not readily develop resistance, with a small specific value of MBC/MIC (1~8). Furthermore, brevilaterins would interact with negatively charged sodium dodecyl sulfate and bind amphipathic soybean phospholipid with an affinity constant of KD = 4.70 × 10−4 M. No significant activity difference was found between brevilaterin B and brevilaterin C. Collectively, this work contributed rich antibacterial data of brevilaterins and revealed the antibacterial regularity beneath these data, which can be used as an activity handbook to instruct their application in food safety.