Evaluation and Adjustment Based on Broad Learning System for Small Signal Stability Analysis of Power System Integrated with Wind Farms

Yang Yu-De,Yao Wen-Jing,Yang Li-Zhen 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

This paper primarily focuses on evaluation and adjustment methods for small signal analysis with wind farm integration. The connection of wind farms may aff ect the original oscillation modes of the system, and may also introduce new oscillation modes. To ensure the security and stability of the system, it is necessary to assess the running state of the system and evaluate the development direction of the small signal stability on the premise of taking volatility into account. It is also important to fast adjust the system when an unstable state happened. The method in this paper provides a new way to accurately evaluate and adjust the stability of the system integrated with wind farms. Broad learning system (BLS) is a non-fi xed model and has the potential of incremental learning. A BLS model is trained to evaluate the damping ratio sensitivity in diff erent operating states. The adjustment part will use the optimal adjustment model and damping ratio sensitivity to adjust unstable systems. The superior performance of the model proposed in this paper is tested by the case study based on the IEEE 3-machine, 9-bus, and the New-England 10-machine, 39-bus. The results demonstrate the feasibility, validity, and eff ectiveness of the method proposed in this article.

Spatiotemporal expression patterns of thymosin and its immune regulation after bacterial stimulation in American cockroach (Periplaneta americana)

Yang Zhen,Xie Jiqin,Yang Yu,Sun Xiaohong,Jing Jie,Shen Yongmei,Yue Bisong,Zhang Xiuyue 한국곤충학회 2021 Entomological Research Vol.51 No.12

Thymosin is a physiologically active polypeptide hormone which has many functions involved in promoting wound healing, promoting hair growth, and accelerating tissue and organ regeneration. American cockroach (Periplaneta americana) has three subtypes thymosin (THY1, THY2, THY3) which are different splices from the same thymosin gene. Real-time PCR was used to detect and analyze the expression differences of THY1 and THY2 in different stages, sexes, tissues and after stimulation by bacteria. Thymosins were expressed in adult, eclosion, and ootheca, and their expression levels were significantly up-regulated during the eclosion period, showing the thymosin might be involved in the eclosion process. The expression levels of thymosins in females were higher than males, and the differences in eclosion stages were more significant (P < 0.01), indicating that they were closely related to development and female reproduction. The expressions of THY1 and THY2 in hemolymph were significantly higher (P < 0.01) than that in other tissues. The up-regulated expression of thymosin in two immune-related tissues (Hemolymph and adipose) after Escherichia coli stimulation further confirmed its involvement in the immune response. Our research would provide a basis for screening of novel pesticides target genes.

GC–MS analysis of chemical constituents and determination of the total antioxidant capacity of adult powder of Periplaneta americana

Yang Zhen,Xie Jiqin,Huang Feiyun,Yang Yu,Zhang Xiuyue,Yue Bisong 한국곤충학회 2022 Entomological Research Vol.52 No.2

Edible insects are alternative sources of high protein. Southeast Asia, South America, Africa, and Europe have recorded edible insects and, especially in Europe and America, there are factories that produce insects as food. In some areas of China, there has also been the habit of eating insects since ancient times. Periplaneta americana is an insect with the homology of medicine and food. In recent years, its medicinal and nutritional functions have attracted extensive attention and research. Its adult powder has been certified as a health product. It not only contains a variety of proteins but also is rich in fatty acids. The composition and antioxidant function of adult powder extract was analyzed in this study. Using adult P. americana powder as the raw material, it was extracted with n-Hexane, dichloromethane, and ethyl acetate, respectively. Gas chromatography–mass spectrometry (GC–MS) removed a total of 60 compounds, and many active components were extracted from P. americana powder for the first time. The parts and relative content of each extracted sample were obtained, and the total antioxidant capacity (T-AOC) of each extracted piece was determined, among which the antioxidant activity of ethyl acetate was the highest.

A New Quorum-Sensing Inhibitor Attenuates Virulence and Decreases Antibiotic Resistance in Pseudomonas aeruginosa

Yu-Xiang Yang,Zhen-Hua Xu,Yu-Qian Zhang,Jing Tian,Li-Xing Weng,Lian-Hui Wang 한국미생물학회 2012 The journal of microbiology Vol.50 No.6

Quorum sensing (QS) has been a novel target for the treatment of infectious diseases. Here structural analogs of Pseudomonas aeruginosa autoinducer N-acyl homoserine lactone (AHL) were investigated for QS inhibitor (QSI) activity and a novel QSI was discovered, N-decanoyl-L-homoserine benzyl ester (C2). Virulence assays showed that C2 downregulated total protease and elastase activities, as well as the production of rhamnolipid, that are controlled by QS in P.aeruginosa wild-type strain PAO1 without affecting growth. C2 was also shown to inhibit swarming motility of PAO1. Using a microdilution checkerboard method, we identified synergistic interactions between C2 and several antibiotics, tobramycin, gentamycin, cefepime, and meropenem. Data from real-time RT-PCR suggested that C2 inhibited the expression of lasR (29.67%), lasI (21.57%), rhlR (28.20%), and rhlI (29.03%).

Simulation analysis and optimization design for wide band piezoelectric oscillator of energy harvesting device

Zhen Yu,Chen-yang Zhang,Si-yang Zhang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

An L type broadband piezoelectric energy harvesting device was proposed in this paper, and the finite element model of L-type piezoelectric vibrator is established and simulated. It shows that the voltage corresponding to the first and third order resonant frequency is 0.06 V and 0.183 V, respectively, although higher than that of the ordinary piezoelectric vibrator, the voltage of the first mode and third mode for the piezoelectric vibrator is not close, which has little effect to broaden the bandwidth. Consequently, the simulation model for multi-cantilever piezoelectric vibrator was established, and its structural sizes were optimized, and it was obtained very close to first and third order resonant voltage, the bandwidth of the vibrator was broadened to 12.5 Hz. The multi-cantilever piezoelectric vibrator can be applied in a variety of devices for the collection of mechanical energy, and to provide a research foundation for the development of intelligent structures with self-sufficiency.

Isoindolin-1-ones from the stems of Nicotiana tabacum and their antiviral activities

Guang-Yu Yang,Jia-Meng Dai,Zhen-Jie Li,Jin Wang,Feng-Xian Yang,Xin Liu,Jing Li,Qian Gao,Xue-Mei Li,Yin-Ke Li,Wei-Guang Wang,Min Zhou,Qiu-Fen Hu 대한약학회 2022 Archives of Pharmacal Research Vol.45 No.8

In previous studies, several isoindolin-1-oneanalogs that exhibited signifi cant anti-tobacco mosaic virus(anti-TMV) activities were isolated from Nicotiana tabacum . Since gene-editing mutants provide a new sample for thediscovery of active metabolites, we focused on the stems ofYN-18–23 (a mutant N. tabacum for gene editing with thealkaloid metabolic pathway cultivated by Yunnan TobaccoCompany), which led to the isolation of four new ( 1–4 )and four known ( 5–8 ) isoindolin-1-ones. To the best of ourknowledge, nicindole C ( 3 ) is the fi rst subclass of isoindolin-1-one bearing a pentacyclic ketone, while nicindole D ( 4 )is the fi rst example of isoindolin-1-one bearing a methylpyridin-2-(1 H )-one moiety. Compounds 1–4 were testedfor their anti-TMV activities, and the results revealed thatcompounds 1 , 3 , and 4 exhibited high anti-TMV activities atconcentrations of 20 μM with inhibition rates of 48.6, 42.8,and 71.5%, respectively. These rates are higher than the inhibitionrate of the positive control (33.2%). The mechanisticstudy of compound 4 , which had the highest anti-TMV activityrevealed that increased potentiation of defense-related enzyme activities and downregulation of expression of theNtHsp70 protein may induce resistance in tobacco againstthe viral pathogen TMV. Molecular docking studies alsorevealed that the isoindolin-1-one substructure is fundamentalfor anti-TMV activity. The methyl-pyridin-2-(1 H )-onemoiety in compound 4 and the 2-oxopropyl groups in compounds1 and 3 at the N -2 position may increase inhibitoryactivities. This study of the structure–activity relationshipis helpful for fi nding new anti-TMV activity inhibitors. Tostudy whether the isoindolin-1-ones have broader antiviralactivities, compounds 1–4 were also tested for their antirotavirusactivities. Compound 4 exhibited high anti-rotavirusactivity with a therapeutic index (TI) value of 20.7. This TI value is close to that of the positive control (20.2).

Whole Cell-mediated Biocatalytic Synthesis of Helicid Cinnamylate and Its Biological Evaluation as a Novel Tyrosinase Inhibitor

Rong-ling Yang,Xi Chen,Yu-ye Song,Qian-lin Zhu,Muhammad Bilal,Yu Wang,Zheng Tong,Ting-ting Wu,Zhao-Yu Wang,Hong-zhen Luo,Xiang-jie Zhao,Ting-ting He 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.3

Tyrosinase inhibitors are clinically effective for treating some dermatological disorders related to melanin hyperpigmentation. Accordingly, the discovery and development of tyrosinase inhibitors have great value in the pharmaceutical and cosmetic industry. Here, a novel tyrosinase inhibitor, 6′-O-cinnamoyl-helicid (helicid cinnamylate) was successfully synthesized by a simple and effective biocatalytic approach with Aspergillus oryzae cells. Investigation of the effects of several key variables on helicid cinnamylate synthesis found that the reaction conversion, reaction rate and regioselectivity reached 99%, 9.40 mM/h and > 99%, respectively, at the optimal conditions with anhydrous acetone as the solvent, whole-cell concentration of 40 mg/mL, and the molar ratio of vinyl cinnamate to helicid of 10 at 45°C. The whole-cells retained 68.87% of its initial activity after reusing for seven batches, indicating a potent application potential in non-aqueous biocatalytic systems. It was worth noting that helicid cinnamylate demonstrated a more potent tyrosinase inhibitory activity with an IC50 value of 3.55 mM than helicid (IC50 = 4.48 mM) and arbutin (IC50 = 5.48 mM), which suggest that helicid cinnamylate could be developed as a more potential tyrosinase inhibitor. In conclusion, this study provides a novel whole-cell catalytic approach for the synthesis of helicid cinnamylate and insight into its application as a tyrosinase inhibitor.

Isolation of Probiotic Piliated Lactobacillus rhamnosus Strains from Human Fecal Microbiota Using SpaA Antiserum-Based Colony Immunoblotting

( Zhen-quan Yang ),( Yu Xue ),( Sheng-qi Rao ),( Mi Zhang ),( Lu Gao ),( Yong-qi Yin ),( Da-wei Chen ),( Xiao-hui Zhou ),( Xin-an Jiao ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.11

Piliated Lactobacillus rhamnosus (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of L. rhamnosus strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti- SpaA-based CIB procedure could quantitatively detect 2.5 × 10³ CFU/ml of pLR colonies spiked in 10⁶ CFU/ml of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent L. rhamnosus strains for commercial purposes.

Estrogen weakens muscle endurance via estrogen receptor-p38 MAPK-mediated orosomucoid (ORM) suppression

Yang Sun,Zhen Qin,Jing-jing Wan,Peng-yuan Wang,Yi-Li Yang,Jian-Guang Yu,Bo-Han Hu,Ding-Feng Su,Zhu-Min Luo,Xia Liu 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Gender differences in fatigue manifest as females being more prone to feel exhaustion and having lower muscle endurance. However, the mechanisms of these effects remain unclear. We investigated whether orosomucoid, an endogenous anti-fatigue protein that enhances muscle endurance, is involved in this regulation. Female rats exhibited lower muscle endurance, and this gender difference disappeared in orosomucoid-1-deficient mice. Female rats also exhibited weaker orosomucoid induction in serum, liver and muscle in response to fatigue compared with male rats. Ovariectomy elevated orosomucoid levels and increased swimming time, and estrogen replenishment reversed these effects. Exogenous estrogen treatment in male and female mice produced opposite effects. Estrogen decreased orosomucoid expression and its promoter activity in C2C12 muscle and Chang liver cells in vitro, and estrogen receptor or p38 mitogen-activated protein kinase blockade abolished this effect. Therefore, estrogen negatively regulates orosomucoid expression that is responsible for the weaker muscle endurance in females.

Study on the Solid Phase Extraction of Hg(II)-SBDTR Chelate with C₁₈ Disks and Its Application to the Determination of Mercury in Tobacco and Tobacco Additive

Yang, Guan-Gyu,Xia, Zhen-Yuang,Wu, Yu-Ping,Sun, Han-Dong,Yin, Jia-Yuan Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.4

A sensitive, selective and rapid method has been developed for the determination of mercury based on the rapid reaction of mercury(II) with p-sulfobenzylidenethiorhodanine (SBDTR) and the solid phase extraction of the colored chelate with $C_{18}$ disks. In the presence of pH 3.5 sodium acetate-acetic acid buffer solution and Emulsifier-OP medium, SBDTR reacts with mercury(II) to form a red chelate of a molar ratio 1 : 2 (mercury to SBDTR). This chelate was prconcentrated by solid phase extraction with $C_{18}$ disks. An enrichment factor of 50 was achieved. The molar absorptivity of the chelate is $1.28{\times}10^5 L{\cdot}mol^{-1}{\cdot}cm^{-1}$ at 545 nm in measured solution. Beer's law is obeyed in the range of 0.01-3 ${\mu}$g/mL. The relative standard deviation for eleven replicates sample of 0.01 ${\mu}$g/mL is 1.65%. This method was applied to the determination of mercury in tobacco and tobacco additive with good results.