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482 results on '"Xia, Yongjun"'

101. bsh1 Gene of Lactobacillus plantarumAR113 Plays an Important Role in Ameliorating Western Diet-Aggravated Colitis

Author

Shao, Junlin, Mu, Zhiyong, Xia, Yongjun, Xiong, Zhiqiang, Song, Xin, Yang, Yijin, Zhang, Hui, Ai, Lianzhong, and Wang, Guangqiang

Abstract

Western diet is thought to increase susceptibility to inflammatory bowel disease (IBD), and probiotics are a potential therapeutic agent for IBD. This study revealed the effects of Lactobacillus plantarumAR113 and L. plantarumAR113Δbsh1 on a dextran sulfate sodium (DSS)-induced colitis mouse model under the Western diet (WD). After four weeks of WD and low-sugar and low-fat diet (LD) intervention, induction with 3% DSS, and intragastric administration of probiotics, we found that L. plantarumAR113 could regulate blood glucose and lipid levels and have a certain protective effect on hepatocytes. Our results suggested that the L. plantarumAR113 alleviated DSS-induced colitis under the Western diet by improving dyslipidemia, repairing intestinal barrier dysfunction, and inhibiting the TLR4/Myd88/TRAF-6/NF-κB inflammatory pathway. However, these changes were not demonstrated in the L. plantarumAR113Δbsh1, and therefore, we reasoned that the presence of bsh1 may play a crucial role in the L. plantarumAR113 exerting its anti-inflammatory function. The relationship between bile salt hydrolase (BSH) and colitis was worthy of further exploration.

Published
2023
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113. A Reactive Power Coordination Control Scheme for Hybrid Multi-Infeed HVDC System

Author

Xia Yongjun, Wei Yao, Jinyu Wen, Bing Yao, Jia Li, and Cai Yan

Subjects
Scheme (programming language), Control theory, Computer science, Filter (video), Control system, Control (management), Voltage source, AC power, computer, Line (electrical engineering), System model, computer.programming_language
Abstract

This paper proposes a reactive power coordination control scheme between voltage source converter based HVDC (VSC-HVDC) system and filter switching of line commutated converter based HVDC (LCC-HVDC) system for a hybrid multi-infeed VSC/LCC HVDC system. The conventional reactive power control strategies of filter switching of LCC-HVDC system and VSC-HVDC system are analyzed, and the limitations of them are pointed out. To reduce the filter switching, a control module is designed for the coordination control scheme. A hybrid multi-infeed system model was built in PSCAD/EMTDC for simulation verification. The simulation results showed that the performance of the reactive power coordinated control is better than that of the reactive power independent control between VSC-HVDC system and LCC-HVDC system.

Published
2020

124. Vibration Analysis of Suspension Cable with Attached Masses by Non-linear Spline Function Method

Author

Qin Jian, Qiao Liang, Chen Jun, Wan Jiancheng, and Xia Yongjun

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

The nonlinear strain and stress expressions of suspension cable are established from the basic condition of suspension structure on the Lagrange coordinates and the equilibrium equation of the suspension structure is obtained. The dynamics equations of motion of the suspended cable with attached masses are proposed according to the virtual work principle. Using the spline function as interpolation functions of displacement and spatial position, the spline function method of dynamics equation of suspension cable is formed in which the stiffness matrix is expressed by spline function, and the solution method of stiffness matrix, matrix assembly method based on spline integral, is put forwards which can save cost time efficiency. The vibration frequency of the suspension cable is calculated with different attached masses, which provides theoretical basis for valuing of safety coefficient of the bearing cable of the cableway.

Published
2016
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125. Catenary Analysis and Calculation Method of Track Rope of Cargo Cableway with Multiple Loads

Author

Qin Jian, Chen Jun, Qiao Liang, Wan Jiancheng, and Xia Yongjun

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

According to actual working condition, the catenary equations of elastic track tope for setting-up is proposed based on the cableway erection requirement, such as the erection angle of end, the initial cable length and midpoint position of cable. The mechanics equilibrium equations, the loads span equations and the consistent equations are presented by analysis of track rope stress state under loads. The nonlinear equations are constructed for elastic track tope with multiple loads and the initial values of newton iteration method are obtained to solve the nonlinear equations. The results of this method are compared with the testing results and numerical results in other literatures and the contrast verifies the reliability of this method. The method is more concise and has smaller amount of calculations with a unified form. It can provide effective means to design the cargo cableway and to check the engineering safety during the erection stage and running stage of cableway.

Published
2016
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126. A Switch State Recognition Method based on Improved VGG19 network

Author

Chuankun Ni, Shiping E, Li Hengxuan, Wang Chengzhi, Xia Yongjun, and Cai Min

Subjects
010302 applied physics, business.industry, Computer science, Deep learning, Activation function, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Pattern recognition, 01 natural sciences, Convolution, Power (physics), Image (mathematics), 0103 physical sciences, Feature (machine learning), Redundancy (engineering), Artificial intelligence, State (computer science), business
Abstract

Intelligent recognition of switch state based on computer vision is one of the important research contents of power intelligence. For solving the problem of low recognition rate under poor imaging environment, this paper presents an improved VGG19 network. There are 3 improved aspects: 1) in the first convolutional layer, the convolution features are extracted from the RGB image and the LBP image of the switch, and then the two convolution features are averaged as the output result of the first convolution layer, in order to enhance the adaptability of features to illumination changes and the ability to extract detailed features; 2) in the subsequent 15 convolution layers, the convolution feature output of each layer is averaged with the original input, and then convolved again, so as to extract detail features by secondary convolution; 3) we selects CReLU instead of ReLU as activation function for reducing the redundancy of the convolution kernel. Experiments show that the new method can greatly improve the performance of switch state recognition.

Published
2019

132. Genes encoding bile salt hydrolase differentially affect adhesion of Lactiplantibacillus plantarumAR113.

Author

Wu, Taoying, Wang, Guangqiang, Tang, Hongyu, Xiong, Zhiqiang, Song, Xin, Xia, Yongjun, Lai, Phoency F‐H, and Ai, Lianzhong

Subjects
BILE salts, CELL aggregation, MICROBIAL adhesion, ADHESION, BILE acids, CHEMICAL industry, GENES
Abstract

BACKGROUND Adhesion is considered important for Lactiplantibacillus to persist in the human gut and for it to exert probiotic effects. Lactiplantibacillus plantarum contains a considerable number and variety of genes encoding bile salt hydrolases (bsh), but their effects on microbial adhesion remain poorly understood. To clarify the effects of four bsh on adhesion, we tried to knock out bsh (Δbsh) of L. plantarum AR113 using the CRISPR‐Cas9 method, and compared the growth, auto‐aggregation (RAA), co‐aggregation (RCA), surface hydrophobicity (AHC) of AR113 wild‐type and Δbsh strains and their adhesion abilities to HT29 cells. RESULTS: We first obtained the AR113 Δbsh1,3,2,4 strain with four bsh knocked out. Their growth was significantly slower than the wild‐type strain cultured in De Man, Rogosa, and Sharpe medium (MRS) with 3.0 g L−1 glyco‐ or tauro‐conjugated bile acid. Bsh had no significant effect on the growth of ten strains cultured in MRS, but Δbsh1 inhibited their growth when cultured in MRS containing 3.0 g L−1 sodium glycocholate, whereas Δbsh4 instead promoted their growth in MRS with 3.0 g L−1 sodium glycocholate and sodium taurocholate. RCA and RAA were linearly positive for all strains except AR113 Δbsh2,4, and AHC and RAA were negatively correlated for most strains excluding AR113 Δbsh2, with RAA = 6.38–25.05%, RCA = 5.17–9.22%, and ACH = 3.22–47.71%. The adhesion ability of ten strains cultured in MRS was higher than that of strains cultured in MRS with 3.0 g L−1 bovine bile, and it was related to bsh2. CONCLUSION: Bsh differentially affected the adhesion of AR113 series strains. This adds to the available information about substrate‐gene‐performance, and provides new information to enable engineering to regulate the colonization of Lactiplantibacillus. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Published
2022
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133. Rapid isolation of exopolysaccharide‐producing Streptococcus thermophilus based on molecular marker screening.

Author

Xiong, Zhiqiang, Chen, Huanlan, Song, Xin, Xia, Yongjun, and Ai, Lianzhong

Subjects
STREPTOCOCCUS thermophilus, LACTOCOCCUS lactis, LACTOBACILLUS casei, FERMENTED milk, POLYMERASE chain reaction, GENE clusters
Abstract

BACKGROUND: As a natural food additive, exopolysaccharide (EPS) produced by Streptococcus thermophilus can improve product viscosity and texture. The protein EpsA is a putative pathway‐specific transcriptional regulator for EPS biosynthesis in S. thermophilus. RESULTS: According to comparative analysis of EPS biosynthetic gene clusters, a conserved region of epsA (609 bp) was employed to design primer pair epsA‐F/R as a molecular marker for the isolation of EPS‐producing (EPS+) S. thermophilus. Two EPS+S. thermophiles strains, AR333 and S‐3, were band‐positive, whereas Lactococcus lactis NZ9000 (non‐EPS‐producing, EPS−), Lactobacillus casei LC2W (EPS+) and L. plantarum AR113 (EPS+) were negative by polymerase chain reaction (PCR) amplicon bands using the epsA probe. This indicated good specificity of the epsA probe to EPS+S. thermophilus. Moreover, based on PCR screening with the epsA probe, 23 positive strains were isolated and identified as S. thermophilus from our microbial library and natural fermented milk with 141.3–309.2 mg L−1 of EPS production, demonstrating the validity of our molecular marker screening method. CONCLUSION: The designed molecular marker of epsA can rapidly screen EPS+S. thermophilus, which has potential application in the dairy and other food industries. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Published
2022
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134. Genetic evidence for the requirements of antroquinonol biosynthesis by Antrodia camphorata during liquid-state fermentation.

Author

Xia, Yongjun, Zhou, Xuan, Liang, Lihong, Liu, Xiaofeng, Li, Hui, Xiong, Zhiqiang, Wang, Guangqiang, Song, Xin, and Ai, Lianzhong

Subjects
*BIOSYNTHESIS, *SOLID-state fermentation, *FERMENTATION, *GENETIC overexpression, *QUINONE, *UBIQUINONES, *ISOPRENYLATION
Abstract

The solid-state fermentation of Antrodia camphorata could produce a variety of ubiquinone compounds, such as antroquinonol (AQ). However, AQ is hardly synthesized during liquid-state fermentation (LSF). To investigates the mechanism of AQ synthesis, three precursors (ubiquinone 0 UQ0, farnesol and farnesyl diphosphate FPP) were added in LSF. The results showed that UQ0 successfully induced AQ production; however, farnesol and FPP could not induce AQ synthesis. The precursor that restricts the synthesis of AQ is the quinone ring, not the isoprene side chain. Then, the Agrobacterium-mediated transformation system of A. camphorata was established and the genes for quinone ring modification (coq2-6) and isoprene synthesis (HMGR, fps) were overexpressed. The results showed that overexpression of genes for isoprene side chain synthesis could not increase the yield of AQ, but overexpression of coq2 and coq5 could significantly increase AQ production. This is consistent with the results of the experiment of precursors. It indicated that the A. camphorata lack the ability to modify the quinone ring of AQ during LSF. Of the modification steps, prenylation of UQ0 is the key step of AQ biosynthesis. The result will help us to understand the genetic evidence for the requirements of AQ biosynthesis in A. camphorata. [ABSTRACT FROM AUTHOR]

Published
2022
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