Vicinal oxygen chelate proteins (VOC) are members of the metalloenzyme superfamily, which plays roles in many biological reactions. Some members of the VOC superfamily have been systematically characterized but not in Brassica napus. In this study, 38 VOC genes were identified based on their conserved domains. The present results revealed that most of the BnaVOC genes have few introns, and all contained the typical VOC structure of βαβββ modules. The BnaVOC genes are distributed unevenly across 15 chromosomes in B. napus and occur as gene clusters on chromosomes C5 and A6. The synteny and phylogenetic analyses revealed that the VOC gene family is a consequence of mesopolyploidy events that occurred in Brassica evolution, and whole-genome duplication and segmental duplication played a major role in the expansion of the BnaVOC gene family. The expression profile analysis indicated that the expression of most BnaVOCs was increased in the leaves and late stage seeds. Further results indicated that seeds of B. napus with a high oil content show higher expression levels under drought stress conditions, suggesting that BnaVOCs not only respond to abiotic stress but may also affect lipid metabolism in drought stress. This present study provides a comprehensive overview of the VOC gene family and provides new insights into their biological function in B. napus evolution.

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This paper presents an underwater lidar time-of-flight ranging system that combines the variable forgivable factor recursive least-squares (VFF-RLS) adaptive filter algorithm and the constant fraction discriminator (CFD) timing technology. The effectiveness of suppressing the backscattering and increasing timing accuracy is experimentally verified in the water basin under the different target distances, especially near the detection limit. The classical RLS is creatively transformed by introducing the VFF, which is highly correlated to the target echo at any distance. The improvement of the signal-to-backscatter ratio always exceeds 18.9 dB. The Monte Carlo simulation proves the applicability of the proposed method in the media of different turbidity. The influences of the selective timing methods on the walk error and time jitter are compared, and the optimum zero point of CFD is achieved by the slope analysis of leading (falling) edge in experimental target pulses.

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This work describes the relationship between the antibacterial activity and the ester chain length (C1-C8) of ( R)-3-Hydroxybutyric (( R)-3-HB) alkyl esters that synthesized from ( R)-3-HB acid (( R)-3-HBA) by esterification reaction. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) decrease as the length of the ( R)-3-HB alkyl ester chain increases from 1 to 6, but ( R)-3-HB-C7 and ( R)-3-HB-C8 have their own rules for different microorganisms. Among them, the ( R)-3HB-C6 has the relatively best antibacterial and antifungal properties, which MIC were 1.95 mg mL−1 against E. coli and S. aureus; 0.98 mg mL−1 against C. albicans and B. subtilis; 0.49 mg mL−1 against A. niger. Finally, the antimicrobial mechanisms of the ( R)-3HB-C6 are revealed, and these include disruption of biofilm and the bacterial wall/membrane, leakage of the intracellular content, and change in the transmembrane potential. These results imply the potential application of ( R)-3-HB alkyl ester as new antimicrobial agents; future research can use this as an antibacterial element to synthesize new polymer materials or agents with high-efficiency antibacterial activity.