Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model

Hong Zhao,Yongping Xu,Gen Li,Xin Liu,Xiaoyu Li,Lili Wang 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives: Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods: SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results: Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions: Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.

CO2-responsive smart wormlike micelles based on monomer and “pseudo” gemini surfactant

Xuepeng Wu,Yongping Huang,Sisi Fang,Caili Dai,Hao Li,Zhongliang Xu,Mingwei Zhao 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-

CO2-responsive wormlike micelles based on monomer erucic acid 3-(N,N-dimethylamino)propylamide (EADP) with or without sodium salicylate (NaSal) in aqueous solution were studied and compared with “pseudo” gemini system. The “pseudo” gemini system were formed by a mixture of EADP and maleic acid (MA) with molar ratio between 2:1–1:1. Different morphological transformations of microstructures in response to EADP concentrations, additives and CO2 stimuli were further investigated in these systems, the wormlike micelle or vesicles can be obtained. The mechanism of these transitions were further investigated by rheology, cryo-TEM and DFT calculation, the results showed that the mechanism behind this transition involved reversible reaction of CO2 with EADP. The mechanism in this research may give further evidence to the self-assembly of CO2-responsive surfactants.

A novel method for longitudinal modification and tooth contact analysis of non-circular cylindrical gears

Dawei Li,Yongping Liu,Jun Gong,Yongqiao Wei,Gang Zhao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12

The traditional geometry of non-circular cylindrical gears provides a contact line between tooth surfaces. In a misaligned non-circular cylindrical gear drive, causing edge contacts that result in noise and vibration. The point contact of the tooth surface is achieved by modification of the driving gear in the longitudinal direction, in order to reduce the sensitivity of tooth surface contact to installation errors. The proposed longitudinal modification method is based on the application of a grinding worm by controlling the center distance of non-circular cylindrical gear and worm. Based on the gear meshing principle, a mathematical model of the tooth surfaces of non-circular cylindrical gears is established, and a parametric tooth surface equation with a unified expression is obtained. Tooth contact analysis (TCA) of non-circular cylindrical gears shows that the contact path and contact area on the tooth surface are shifted with the change of installation error, but still distributed in the middle of the tooth surface without creating edge contact. The transmission error is increased with the growth of installation error. Tooth modification in a longitudinal direction has an obvious improvement effect on the bad tooth contact condition, but too large a tooth modification parameter will make the tooth surface load distribution concentrated in a smaller area, which results in the decrease of gear load capacity.

A Bidirectional Three-level DC-DC Converter with a Wide Voltage Conversion Range for Hybrid Energy Source Electric Vehicles

Wang, Ping,Zhao, Chendong,Zhang, Yun,Li, Jing,Gao, Yongping The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

A Bidirectional Three-level DC-DC Converter with a Wide Voltage Conversion Range for Hybrid Energy Source Electric Vehicles

Ping Wang,Chendong Zhao,Yun Zhang,Jing Li,Yongping Gao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

An Improved Centroid Localization algorithm for WSN

Li ShiWei,Ding Mingli,Zhao YongPing 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.6

In wireless sensor networks (WSN) research area, node localization is one of the most important techniques. An improved Centroid localization algorithm is analyzed and an improved Centroid algorithm with selective anchor node localization algorithm (CSA) for WSN will proposed in this paper. The key point of the algorithm is the most discrepant estimation nodes are selected by the nearest reference anchor node around a distance unknown node. The triangle centroid and the polygon centroid are employed to calculate the coordinates of the estimation nodes to improve node locating precision. MATLAB simulation illustrate that the algorithm is valid and feasible.

Parameters Estimation of Automotive Ignition Coils Based on Support Vector Regression

Qisong Wang,Song Li,Yongping Zhao 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Ignition coils is an important part of automotive ignition system, which directly influences the vehicle’s power performance, energy consumption and environmental protection property. In this paper, a MIMO model based on support vector regression (SVR) is proposed aiming at estimating technological parameters of automotive ignition coils. With the performance parameters, such as spark current and ignition energy as inputs, the model can reach the goal to estimate the technological parameters such as windings and wire diameters of primary coils and secondary coils by choosing appropriate SVR parameters, kernel functions and training algorithm. Furthermore, experimental samples of ignition coils are specially designed, manufactured and measured to obtain training data. Simulated results prove the rationality and accuracy of the model, which shows that the model can provide guidance for the design of ignition coils.

Calculating Jacking Forces for Circular Pipes with Welding Flange Slabs from a Combined Theory and Case Study

Pengjiao Jia,Baofeng Jiang,Wen Zhao,Yongping Guan,Jianyong Han,Cheng Cheng 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.4

Recently, the Steel Tube Slab (STS) curtain method has been successfully used in the construction of ultra-shallow metro stations in modern urban areas. By using the STS curtain method, the external surfaces of pipes are welded with flange slabs, and then the pipes are jacked into soils. However, the nature and extent of the influence of flange slabs on the calculation of jacking force is unclear. This paper presents the first combined theoretical and case study to calculate the increase of jacking forces for circular steel pipes with welded flange slabs during the entire jacking process. The increase of jacking forces was assumed to balance the friction at the soil-pipeline interface. Theoretical formulae were firstly developed to calculate earth pressure based on pressure arch theory and elastic foundation beam theory. A case study was then performed to verify the theoretical results with the field data from Olympic Metro Station on the Shenyang Metro Line 9 in China. Subsequently, factors influencing the calculation of jacking force were analyzed and discussed. Results show that the theoretical formulae produced good results with minor errors. The implications of these findings regarding the prediction of jacking force and selection of hydraulic jack are discussed.

On-line Measurement of Internal Resistance of Lithium Ion Battery for EV and its Application Research

Hua Zhang,Rengui Lu,Chunbo Zhu,Yongping Zhao 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.4