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Abstract Background Seven-carbon sugars, which rarely exist in nature, are the key constitutional unit of septacidin and hygromycin B in bacteria. These sugars exhibit a potential therapeutic effect for hypoglycaemia and cancer and serve as building blocks for the synthesis of C-glycosides and novel antibiotics. However, chemical and enzymatic approaches for the synthesis of seven-carbon sugars have faced challenges, such as complex reaction steps, low overall yields and high-cost feedstock, limiting their industrial-scale production. Results In this work, we propose a strain engineering approach for synthesising sedoheptulose using glucose as sole feedstock. The gene pfkA encoding 6-phosphofructokinase in Corynebacterium glutamicum was inactivated to direct the carbon flux towards the pentose phosphate pathway in the cellular metabolic network. This genetic modification successfully enabled the synthesis of sedoheptulose from glucose. Additionally, we identified key enzymes responsible for product formation through transcriptome analysis, and their corresponding genes were overexpressed, resulting in a further 20% increase in sedoheptulose production. Conclusion We achieved a sedoheptulose concentration of 24 g/L with a yield of 0.4 g/g glucose in a 1 L fermenter, marking the highest value up to date. The produced sedoheptulose could further function as feedstock for synthesising structural seven-carbon sugars through coupling with enzymatic isomerisation, epimerisation and reduction reactions.

AbstractObjective Accumulating evidence suggests that differentially expressed circular RNAs (circRNAs) play critical roles in immune cells of systemic lupus erythematosus (SLE) patients. Hsa_circ_0000479 has been studied in the field of cancer and infection, whereas seldom studied in autoimmune diseases. The aim of this study was to investigate the role and clinical value of neutrophil hsa_circ_0000479 in SLE.Methods The expression levels of hsa_circ_0000479 in both healthy individuals and SLE patients’ neutrophils were detected by qPCR and compared with those in peripheral blood mononuclear cells (PBMCs) . In addition, the correlation of hsa_circ_0000479 levels in neutrophils with the clinical and immunological features of SLE patients was also analysed.Results The expression levels of hsa_circ_0000479 in the patients with SLE were significantly higher in neutrophils than that of PBMCs, and also significantly higher than that in healthy controls (HCs). Moreover, the expression levels of hsa_circ_0000479 in neutrophils were negatively associated with absolute neutrophil count and complement 3 (C3), whereas positively correlated with anti-dsDNA and anti-nucleosome antibodies in SLE. In addition, SLE patients with higher levels of hsa_circ_0000479 demonstrated more several clinical manifestations, including Raynaud’s phenomenon, alopecia and leucopenia.Conclusions Hsa_circ_0000479 is up-regulated in neutrophils of SLE patients, and is also associated with several important laboratory indicators and clinical manifestations, suggesting that hsa_circ_0000479 in neutrophils was one of probable factors involved in the pathogenesis of SLE with potential clinical value.

To obtain a safe and efficient β-glucosidase for preparing icariside II from icariin by biocatalytic hydrolysis, a GRAS (generally recognized as safe) strain Bacillus subtilis WB600 was used as the host to produce a thermophilic β-glucosidase from Thermotoga petrophila, by construction of a Escherichia coli-Bacillus subtilis shuttle vector pMA5. Enzymatic properties of the recombinant enzyme and its process conditions of hydrolyzing icariin to prepare icariside II were studied. The result showed that after cultivated in SR culture for 48 h at 30 ℃, the activity of β-glucosidase in the fermented broth reached to 69.68 U/mL. TpBgl3 exhibited the maximal activity at 85 °C and pH4.0. More than 85% of the maximum activity was retained after incubation at 65 °C and pH4.0 for 3 h. Under optimized conditions of 65 °C, pH4.0, and 0.16 U/mg enzyme dosage, the recombinant enzyme could transform 10 g/L icariin into 7.50 g/L icariside II in 20 min with a molar conversion of 98.67%. The successful secretory expression of β-glucosidase in Bacillus subtilis could provide new ways to the industrial safe and efficient biopreparation of icariside II and other high-value-added aglycon compounds.

Uncrewed surface vehicles (USVs) have gained significant attention in the past decade due to their potential commercial applications and a vast global market. An essential capability of USVs is autonomous obstacle avoidance in oceanic environments to prevent collisions. This study focuses on investigating and benchmarking deep learning-based real-time object detection algorithms for collision avoidance in USVs. The candidate algorithms were trained and evaluated using a maritime dataset provided by Marine Thinking Inc. Among the algorithms tested, You Only Look Once (YOLO) v5m demonstrated outstanding performance (mAP50 > 0.84 and mAP50:95 > 0.69) and high frame per second (FPS > 60) in realtime scenarios. Subsequently, the pre-trained YOLO v5m algorithm was converted into a TensorRT engine and deployed within a DeepStream pipeline on an onboard Nvidia Jetson for real-time collision avoidance tests. The results indicate that the YOLO v5m algorithm successfully detected obstacles and provided feedback to the ArduPilot autonomous suite. The ArduPilot, in turn, adjusted the control signal of the USV motor based on the Bendy Ruler obstacle avoidance algorithm, resulting in the successful avoidance of detected obstacles, and preventing collisions. This study presents an efficient, production-ready, and cost-effective autonomous collision avoidance methodology for USVs. [ABSTRACT FROM AUTHOR]