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Yafei Duan,Yue Zhang,Hongbiao Dong,Yun Wang,Jiasong Zhang 한국미생물학회 2017 The journal of microbiology Vol.55 No.12
Poly-β-hydroxybutyrate (PHB) is a natural polymer of the short chain fatty acid β-hydroxybutyrate, which acts as a microbial control agent. The mammalian target of the rapamycin (mTOR) signaling pathway plays a crucial role in intestine inflammation and epithelial morphogenesis. In this study, we examined the composition of intestine microbiota, and mTOR signaling-related gene expression in Pacific white shrimp Litopenaeus vannamei fed diets containing different levels of PHB: 0% (Control), 1% (PHB1), 3% (PHB3), and 5% (PHB5) (w/w) for 35 days. High-throughput sequencing analysis revealed that dietary PHB altered the composition and diversity of intestine microbiota, and that the microbiota diversity decreased with the increasing doses of PHB. Specifically, dietary PHB increased the relative abundance of Proteobacteria and Tenericutes in the PHB1 and PHB5 groups, respectively, and increased that of Gammaproteobacteria in the three PHB groups. Alternatively, PHB decreased Alphaproteobacteria in the PHB3 and PHB5 groups. At the genus level, dietary PHB increased the abundance of beneficial bacteria, such as Bacillus, Lactobacillus, Lactococcus, Clostridium, and Bdellovibrio. The relative mRNA expression levels of the mTOR signaling-related genes TOR, 4E-BP, eIF4E1α, and eIF4E2 all increased in the three PHB treatment groups. These results revealed that dietary PHB supplementation had a beneficial effect on intestine health of L. vannamei by modulating the composition of intestine microbiota and activating mTOR signaling.
Yafei Chen,Hailong Zhang,Dong-Hee Kim,Sung-Jun Park,Seong-Mi Park 한국산업융합학회 2020 한국산업융합학회 논문집 Vol.23 No.2
In wireless power transfer (WPT) system, the conventional compensation topologies only can provide a constant current (CC) or constant voltage (CV) output under their resonant conditions. It is difficult to meet the CC and CV hybrid charging requirements without any other schemes. In this study, a switching hybrid topology (SHT) is proposed for CC and CV electric vehicle (EV) battery charging. By utilizing an additional capacitor and two AC switches (ACSs), a double-side LCC (DS-LCC) and an inductor and double capacitors-series (LCC-S) topologies are combined. According to the specified CC and CV charging profile, the CC and CV charging modes can be flexibly converted by the two additional ACSs. In addition, zero phase angle (ZPA) also can be achieved in both charging modes. In this method, because the operating frequency is fixed, without using PWM control, and only a small number of devices are added, it has the benefits of low-cost, easy-controllability and high efficiency. A 3.3-kW experimental prototype is configured to verify the proposed switching hybrid charger. The maximum DC efficiencies (at 3.3-kW) of the proposed SHT is 92.58%.
Yafei Li,Xiaocheng Lan,Boyang Liu,Tiefeng Wang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-
A stable and highly efficient supported Cu-Ni catalysts for the conversion of ethyl levulinate (EL) toc-valerolactone (GVL) was developed. The catalysts were characterized by XRD, TEM, TPD, TPR, andXPS. The support effect of metal oxides (Al2O3, SiO2, ZrO2, and TiO2) revealed that Cu-Ni supported onAl2O3 showed the highest activity for EL hydrogenation to ethyl 4-hydroxypentanoate (EHP) and thesubsequent intramolecular esterification of EHP to GVL. EHP intramolecular esterification to GVL in theethanol solution was a reversible reaction with an equilibrium constant of 24 at 453 K. A simplified reactionkinetic network was established. The solvent had a significant influence on the reaction equilibriumand the catalyst stability. Cu-Ni/Al2O3 in n-hexane solvent gave a higher GVL yield than that in ethanolsolvent, and showed better recyclability than that in toluene solvent. With optimizing the conditions, Cu-Ni/Al2O3 gave 99.9% conversion and 98% selectivity to GVL with a space–time yield of 1.13 gGVL gcat-1 h1 inn-hexane solvent with good recyclability.