Review : Characterizing LipR from Pseudomonas sp. R0-14 and Applying in Enrichment of Polyunsaturated Fatty Acids from Algal Oil

( Wenjuan Yang ),( Li Xu ),( Houjin Zhang ),( Yunjun Yan ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.11

In this study, Pseudomonas R0-14, which was isolated from Arctic soil samples, showed a clear halo when grown on M9 medium agarose plates containing olive oil-rhodamine B as substrate, suggesting that it expressed putative lipase(s). A putative lipase gene, lipR, was cloned from R0-14 by genome walking and Touchdown PCR. lipR encodes a 562-amino-acid polypeptide showing a typical α/β hydrolase structure with a catalytic triad consisting of Ser153-Asp202-His260 and one α-helical lid (residues 103-113). A phylogenetic analysis revealed that LipR belongs to the lipase subfamily I.3. LipR was successfully expressed in Escherichia coli, purified, and biochemically characterized. Recombinant LipR exhibited its maximum activity towards p-nitrophenyl butyrate at pH 8.5 and 60oC with a Km of 0.37 mM and a kcat of 6.42 s-1. It retained over 90% of its original activity after incubation at 50oC for 12 h. In addition, LipR was activated by Ca2+, Mg2+, Ba2+, and Sr2+, while strongly inhibited by Cu2+, Zn2+, Mn2+, and ethylenediaminetetraacetic acid. Moreover, it showed a certain tolerance to organic solvents, including acetonitrile, isopropanol, acetone, methanol, and tert-butanol. When algal oil was hydrolyzed by LipR for 24 h, there was an enrichment of n-3 long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (1.22%, 1.65-fold), docosapentaenoic acid (21.24%, 2.04-fold), and docosahexaenoic acid (36.98%, 1.33-fold), and even a certain amount of diacylglycerols was also produced. As a result, LipR has great prospect in industrial applications, especially in food and/or cosmetics applications.

Multi-objective Fuzzy-optimization of Crowbar Resistances for the Low-Voltage Ride-through of Doubly Fed Induction Wind Turbine Generation Systems

Wenjuan Zhang,Haomiao Ma,Junli Zhang,Lingling Chen,Yang Qu 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

This study investigates the multi-objective fuzzy optimization of crowbar resistance for the doubly fed induction generator (DFIG) low-voltage ride-through (LVRT). By integrating the crowbar resistance of the crowbar circuit as a decision variable, a multi-objective model for crowbar resistance value optimization has been established to minimize rotor overcurrent and to simultaneously reduce the DFIG reactive power absorbed from the grid during the process of LVRT. A multi-objective genetic algorithm (MOGA) is applied to solve this optimization problem. In the proposed GA, the value of the crowbar resistance is represented by floating-point numbers in the GA population. The MOGA emphasizes the non-dominated solutions and simultaneously maintains diversity in the non-dominated solutions. A fuzzy-set-theory-based is employed to obtain the best solution. The proposed approach has been evaluated on a 3 MW DFIG LVRT. Simulation results show the effectiveness of the proposed approach for solving the crowbar resistance multi-objective optimization problem in the DFIG LVRT.

Three-Phase Static Var Generator Based on Z-Source Network

Yang Dongyang,Li Wenjuan,Cheng Jingsi 보안공학연구지원센터 2013 International Journal of Control and Automation Vol.6 No.6

Aerodynamic force characteristics and galloping analysis of iced bundled conductors

Wenjuan Lou,M.F. Huang,Jiang Lv,Lun Yang,Dong Yan 한국풍공학회 2014 한국풍공학회지 Vol.18 No.2

Aerodynamic characteristics of crescent and D-shape bundled conductors were measured by high frequency force balance technique in the wind tunnel. The drag and lift coefficients of each sub-conductor and the whole bundled conductors were presented under various attack angles of wind. The galloping possibility of bundled conductors is discussed based on the Den Hartog criterion. The influence of icing thickness, initial ice accretion angle and sub-conductor on the aerodynamic properties were investigated. Based on the measured aerodynamic force coefficients, a computationally efficient finite element method is also implemented to analyze galloping of iced bundled conductors. The analysis results show that each sub-conductor of the bundled conductor has its own galloping feature due to the use of aerodynamic forces measured separately for every single sub-conductors.

PMDV-hop: An effective range-free 3D localization scheme based on the particle swarm optimization in wireless sensor network

( Wenjuan Wang ),( Yuwang Yang ),( Lei Wang ),( Wei Lu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.1

Location information of individual nodes is important in the implementation of necessary network functions. While extensive studies focus on localization techniques in 2D space, few approaches have been proposed for 3D positioning, which brings the location closer to the reality with more complex calculation consumptions for high accuracy. In this paper, an effective range-free localization scheme is proposed for 3D space localization, and the sensitivity of parameters is evaluated. Firstly, we present an improved algorithm (MDV-Hop), that the average distance per hop of the anchor nodes is calculated by root-mean-square error (RMSE), and is dynamically corrected in groups with the weighted RMSE based on group hops. For more improvement in accuracy, we expand particle swarm optimization (PSO) of intelligent optimization algorithms to MDV-Hop localization algorithm, called PMDV-hop, in which the parameters (inertia weight and trust coefficient) in PSO are calculated dynamically. Secondly, the effect of various localization parameters affecting the PMDV-hop performance is also present. The simulation results show that PMDV-hop performs better in positioning accuracy with limited energy.

Probiotics-loaded microcapsules from gas-assisted microfluidics for inflammatory bowel disease treatment

Xiaowei Yang,Cuihong Li,Hai Yu,Jinping Tang,Qinfang Wu,Wenjuan Qu 한국고분자학회 2023 Macromolecular Research Vol.31 No.8

Inflammatory bowel disease (IBD) is a kind of chronic inflammatory disease that is difficult to cure completely and may cause cancer. Modulating the intestinal flora is believed to be a feasible approach for IBD treatment. However, the traditional probiotics delivery systems often suffer from the inactivation caused by gastric acid. Herein, we proposed a novel probiotics-loaded microcapsule generated from a gas-assisted microfluidic platform. The microcapsules were composed of alginate shells and probiotics-containing cores, and exhibited good sphericity and biocompatibility, and had an average size of about 325 μm and a coefficient of variation of 2.57%. When the probiotics-loaded microcapsules were used for the IBD treatment of mice, they displayed good therapeutic effects in modulating oxidative stress and inflammation as well as protecting the intestinal barrier. These features indicate that the prepared probiotics-loaded microcapsules could be used as new materials for IBD treatment.

Multi-objective Fuzzy-optimization of Crowbar Resistances for the Low-Voltage Ride-through of Doubly Fed Induction Wind Turbine Generation Systems

Zhang, Wenjuan,Ma, Haomiao,Zhang, Junli,Chen, Lingling,Qu, Yang The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

This study investigates the multi-objective fuzzy optimization of crowbar resistance for the doubly fed induction generator (DFIG) low-voltage ride-through (LVRT). By integrating the crowbar resistance of the crowbar circuit as a decision variable, a multi-objective model for crowbar resistance value optimization has been established to minimize rotor overcurrent and to simultaneously reduce the DFIG reactive power absorbed from the grid during the process of LVRT. A multi-objective genetic algorithm (MOGA) is applied to solve this optimization problem. In the proposed GA, the value of the crowbar resistance is represented by floating-point numbers in the GA population. The MOGA emphasizes the non-dominated solutions and simultaneously maintains diversity in the non-dominated solutions. A fuzzy-set-theory-based is employed to obtain the best solution. The proposed approach has been evaluated on a 3 MW DFIG LVRT. Simulation results show the effectiveness of the proposed approach for solving the crowbar resistance multi-objective optimization problem in the DFIG LVRT.

Effect of ground ginger on dough and biscuit characteristics and acrylamide content

Huaijie Yang,Lin Li,Yongpo Yin,Bing Li,Xia Zhang,Wenjuan Jiao,Yi Liang 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.5

Effect of different contents of ground ginger[0%, 1%, 3%, 5%, and 7% (w/w)] on flour quality, doughand biscuit characteristic and acrylamide content wereinvestigated. Texture results showed that by adding 1% (w/w) ground ginger, hardness of dough, hardness andchewiness of biscuit decreased, which was beneficial forbiscuit making. Moreover, the L* value of biscuit droppedwhile the a* and b* value rose with the increase of gingercontents, indicating darker, redder and yellower biscuits. Sensory score of biscuits became worse but acrylamidecontent reduced with the addition of ground ginger. Thephenol hydroxyl group of gingerol played a more importantrole in the reaction of formation of acrylamide than the sidechain. Finally, biscuit with 1% ground ginger contentshowed good texture, color and acceptable sensory evaluation,as well as lowering the acrylamide content by 6.2%.

Extracellular products-mediated interspecific interaction between Pseudomonas aeruginosa and Escherichia coli

Yuan Yang,Li Jing,Lin Jiafu,Pan Wenjuan,Chu Yiwen,Prithiviraj Balakrishnan,Guo Yidong,Wang Xinrong,Zhao Kelei 한국미생물학회 2021 The journal of microbiology Vol.59 No.1

The Gram-negative pathogen Pseudomonas aeruginosa adopts several elaborate strategies to colonize a wide range of natural or clinical niches and to overcome the neighboring bacterial competitors in polymicrobial communities. However, the relationship and interaction mechanism of P. aeruginosa with other bacterial pathogens remains largely unexplored. Here we explore the interaction dynamics of P. aeruginosa and Escherichia coli, which frequently coinfect the lungs of immunocompromised hosts, by using a series of on-plate proximity assays and RNA-sequencing. We show that the extracellular products of P. aeruginosa can inhibit the growth of neighboring E. coli and induce a large-scale of transcriptional reprogramming of E. coli, especially in terms of cellular respiration- related primary metabolisms and membrane components. In contrast, the presence of E. coli has no significant effect on the growth of P. aeruginosa in short-term culture, but causes a dysregulated expression of genes positively controlled by the quorum-sensing (QS) system of P. aeruginosa during subsequent pairwise culture. We further demonstrate that the divergent QS-regulation of P. aeruginosa may be related to the function of the transcriptional regulator PqsR, which can be enhanced by E. coli culture supernatant to increase the pyocyanin production by P. aeruginosa in the absence of the central las-QS system. Moreover, the extracellular products of E. coli promote the proliferation and lethality of P. aeruginosa in infecting the Caenorhabditis elegans model. The current study provides a general characterization of the extracellular products-mediated interactions between P. aeruginosa and E. coli, and may facilitate the understanding of polymicrobial infections.

Reconstruction of Wideband Radar Signal Based on Compressed Sensing

Li Wenjuan,Yang Haolan 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.8

The matched filter is often used for the radar receiving terminal, but such application in wideband radar may cause complex system and high cost. The adoption of compressed sensing can not only remove the matched filter and the high-speed analog-digital converter, but also realize high-resolution radar imaging. In consideration of the sparseness of the radar target scene, a compressed sensing method used for chaotic radar is proposed in this article, wherein the chaotic frequency-modulated signal is generated by Bernoulli mapping and the randomness of such signal can be directly used for constructing the observation matrix. Meanwhile, the under-sampled echo signal can be used for radar scene reconstruction through the optimization technology. According to the simulation of stationary and non-stationary target radar scenes, compared with the matched filter processing technology, the proposed method has simple processing procedure and optimal performance, and the feasibility of this method is also verified by the simulation result.