Unbalance Control Strategy of Boost Type Three-Phase to Single-Phase Matrix Converters Based on Lyapunov Function

Xu, Yu-xiang,Ge, Hong-juan,Guo, Hai The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

This paper analyzes the input side performance of a conventional three-phase to single-phase matrix converter (3-1MC). It also presents the input-side waveform quality under this topology. The suppression of low-frequency input current harmonics is studied using the 3-1MC plus capacitance compensation unit. The constraint between the modulation function of the output and compensation sides is analyzed, and the relations among the voltage utilization ratio and the output compensation capacitance, filter capacitors and other system parameters are deduced. For a 3-1MC without large-capacity energy storage, the system performance is susceptible to input voltage imbalance. This paper decouples the inner current of the 3-1MC using a Lyapunov function in the input positive and negative sequence bi-coordinate axes. Meanwhile, the outer loop adopts a voltage-weighted synthesis of the output and compensation sides as a cascade of control objects. Experiments show that this strategy suppresses the low-frequency input current harmonics caused by input voltage imbalance, and ensures that the system maintains good static and dynamic performances under input-unbalanced conditions. At the same time, the parameter selection and debugging methods are simple.

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%).

Knocking Down Nucleolin Expression Enhances the Radiosensitivity of Non-Small Cell Lung Cancer by Influencing DNA-PKcs Activity

Xu, Jian-Yu,Lu, Shan,Xu, Xiang-Ying,Hu, Song-Liu,Li, Bin,Qi, Rui-Xue,Chen, Lin,Chang, Joe Y. Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Nucleolin (C23) is an important anti-apoptotic protein that is ubiquitously expressed in exponentially growing eukaryotic cells. In order to understand the impact of C23 in radiation therapy, we attempted to investigate the relationship of C23 expression with the radiosensitivity of human non-small cell lung cancer (NSCLC) cells. We investigated the role of C23 in activating the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), which is a critical protein for DNA double-strand breaks (DSBs) repair. As a result, we found that the expression of C23 was negatively correlated with the radiosensitivity of NSCLC cell lines. In vitro clonogenic survival assays revealed that C23 knockdown increased the radiosensitivity of a human lung adenocarcinoma cell line, potentially through the promotion of radiation-induced apoptosis and adjusting the cell cycle to a more radiosensitive stage. Immunofluorescence data revealed an increasing quantity of ${gamma}$-H2AX foci and decreasing radiation-induced DNA damage repair following knockdown of C23. To further clarify the mechanism of C23 in DNA DSBs repair, we detected the expression of DNA-PKcs and C23 proteins in NSCLC cell lines. C23 might participate in DNA DSBs repair for the reason that the expression of DNA-PKcs decreased at 30, 60, 120 and 360 minutes after irradiation in C23 knockdown cells. Especially, the activity of DNA-PKcs phosphorylation sites at the S2056 and T2609 was significantly suppressed. Therefore we concluded that C23 knockdown can inhibit DNA-PKcs phosphorylation activity at the S2056 and T2609 sites, thus reducing the radiation damage repair and increasing the radiosensitivity of NSCLC cells. Taken together, the inhibition of C23 expression was shown to increase the radiosensitivity of NSCLC cells, as implied by the relevance to the notably decreased DNA-PKcs phosphorylation activity at the S2056 and T2609 clusters. Further research on targeted C23 treatment may promote effectiveness of radiotherapy and provide new targets for NSCLC patients.

Ginsenoside Rh2 reduces depression in offspring of mice with maternal toxoplasma infection during pregnancy by inhibiting microglial activation via the HMGB1/TLR4/NF-kB signaling pathway

Xiang Xu,Yu-Nan Lu,Jia-Hui Cheng,Hui-Wen Lan,Jing-Mei Lu,Guang-Nan Jin,Guang-Hua Xu,Cheng-Hua Jin,Juan Ma,Hu-Nan Piao,Xuejun Jin,Lian-Xun Piao 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.1

Background: Maternal Toxoplasma gondii (T. gondii) infection during pregnancy has been associated with various mental illnesses in the offspring. Ginsenoside Rh2 (GRh2) is a major bioactive compound obtained from ginseng that has an anti-T. gondii effect and attenuates microglial activation through toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-kB) signaling pathway. GRh2 also alleviated tumor-associated or lipopolysaccharide-induced depression. However, the effects and potential mechanisms of GRh2 on depression-like behavior in mouse offspring caused by maternal T. gondii infection during pregnancy have not been investigated. Methods: We examined GRh2 effects on the depression-like behavior in mouse offspring, caused by maternal T. gondii infection during pregnancy, by measuring depression-like behaviors and assaying parameters at the neuronal and molecular level. Results: We showed that GRh2 significantly improved behavioral measures: sucrose consumption, forced swim time and tail suspended immobility time of their offspring. These corresponded with increased tissue concentrations of 5-hydroxytryptamine and dopamine, and attenuated indoleamine 2,3-dioxygenase or enhanced tyrosine hydroxylase expression in the prefrontal cortex. GRh2 ameliorated neuronal damage in the prefrontal cortex. Molecular docking results revealed that GRh2 binds strongly to both TLR4 and high mobility group box 1 (HMGB1). Conclusion: This study demonstrated that GRh2 ameliorated the depression-like behavior in mouse offspring of maternal T. gondii infection during pregnancy by attenuating the excessive activation of microglia and neuroinflammation through the HMGB1/TLR4/NF-kB signaling pathway. It suggests that GRh2 could be considered a potential therapy in preventing and treating psychiatric disorders in the offspring mice of mothers with prenatal exposure to T. gondii infection.

Unbalance Control Strategy of Boost Type Three-Phase to Single-Phase Matrix Converters Based on Lyapunov Function

Yu-xiang Xu,Hongjuan Ge,Hai Guo 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

This paper analyzes the input side performance of a conventional three-phase to single-phase matrix converter (3-1MC). It alsopresents the input-side waveform quality under this topology. The suppression of low-frequency input current harmonics isstudied using the 3-1MC plus capacitance compensation unit. The constraint between the modulation function of the output andcompensation sides is analyzed, and the relations among the voltage utilization ratio and the output compensation capacitance,filter capacitors and other system parameters are deduced. For a 3-1MC without large-capacity energy storage, the systemperformance is susceptible to input voltage imbalance. This paper decouples the inner current of the 3-1MC using a Lyapunovfunction in the input positive and negative sequence bi-coordinate axes. Meanwhile, the outer loop adopts a voltage-weightedsynthesis of the output and compensation sides as a cascade of control objects. Experiments show that this strategy suppressesthe low-frequency input current harmonics caused by input voltage imbalance, and ensures that the system maintains good staticand dynamic performances under input-unbalanced conditions. At the same time, the parameter selection and debugging methodsare simple.

Microstructure evolution and effect on deuterium retention in oxide dispersion strengthened tungsten during He⁺ irradiation

Ding, Xiao-Yu,Xu, Qiu,Zhu, Xiao-yong,Luo, Lai-Ma,Huang, Jian-Jun,Yu, Bin,Gao, Xiang,Li, Jian-Gang,Wu, Yu-Cheng Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.12

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

High-risk Human Papillomavirus Genotypes in Cervical Lesions and Vaccination Challenges in China

Xu, Qiu-Xiang,Zhang, Zhen-Yu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Cervical cancer, mostly progressing from cervical intraepithelial neoplasia, is a major cause of morbidity and mortality in Chinese women. This is largely due to high prevalence of high-risk human papillomaviruses (hr-HPVs) in the population. The prevalence of hr-HPV DNA in women and in cervical lesions women ranged from 9.9% to 17.% and from 50.5% to 70.9% in different regions of China, respectively. The most common genotypes somewhat differ between regions throughout the country and from those in many other countries. This may be a challenge to cervical cancer screening and prevention in China. Combined detection of particular HPV genotypes should be recommended in all geographical regions in China and greater attention must be paid to specific hr-HPV types during cervical cancer screening and follow-up of cervical lesions. Besides, vaccination for prevention of cervical cancer by particular HPV genotypes, has not been introduced to China so far. Updated knowledge on prevalent HPV genotypes should be provided to public health organizations to help with the development of more effective HPV vaccines, which can protect Chinese women against HPV types prevalent in local China and thus have a substantial impact on the cervical cancer burden.

Cloning and Sequence Analysis of a Glyceraldehyde-3-phosphate Dehydrogenase Gene from Ganoderma lucidum

Xu Fei,Ming Wen Zhao,Yu Xiang Li 한국미생물학회 2006 The journal of microbiology Vol.44 No.5

A cDNA library of Ganoderma lucidum has been constructed using a Zap Express cloning vector. A glyceraldehyde-3-phosphate dehydrogenase gene (gpd) was isolated from this library by hybridization of the recombinant phage clones with a gpd-specific gene probe generated by PCR. By comparison of the cDNA and the genomic DNA sequences, it was found that the complete nucleotide sequence encodes a putative polypeptide chain of 338 amino acids interrupted by 6 introns. The predicted amino acid sequence of this gene shows a high degree of sequence similarity to the GPD proteins from yeast and filamentous fungi. The promoter region contains a CT-rich stretch, two CAAT boxes, and a consensus TATA box. The possibility of using the gpd promoter in the construction of new transformation vectors is discussed.

How can anomalous western North Pacific Subtropical High intensify in late summer? : WESTERN NORTH PACIFIC SUBTROPICAL HIGH

Xiang, Baoqiang,Wang, Bin,Yu, Weidong,Xu, Shibin American Geophysical Union 2013 Geophysical research letters Vol.40 No.10

Association of Novel Polymorphisms in Lymphoid Enhancer Binding Factor 1 (LEF-1) Gene with Number of Teats in Different Breeds of Pig

Xu, Ru-Xiang,Wei, Ning,Wang, Yu,Wang, Guo-Qiang,Yang, Gong-She,Pang, Wei-Jun Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.9

Lymphoid enhancer binding factor 1 (LEF-1) is a member of the T-cell specific factor (TCF) family, which plays a key role in the development of breast endothelial cells. Moreover, LEF-1 gene has been identified as a candidate gene for teat number trait. In the present study, we detected two novel mutations (NC_010450.3:g. 99514A>G, 119846C>T) by DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism in exon 4 and intron 9 of LEF-1 in Guanzhong Black, Hanjiang Black, Bamei and Large White pigs. Furthermore, we analyzed the association between the genetic variations with teat number trait in these breeds. The 99514A>G mutation showed an extremely significant statistical relevance between different genotypes and teat number trait in Guanzhong (p<0.001) and Large White (p = 0.002), and significant relevance in Hanjiang (p = 0.017); the 119846C>T mutation suggested significant association in Guanzhong Black pigs (p = 0.042) and Large White pigs (p = 0.003). The individuals with "AG" or "GG" genotype displayed more teat numbers than those with "AA"; the individuals with "TC" or "CC" genotype showed more teat numbers than those with "TT". Our findings suggested that the 99514A>G and 119846C>T mutations of LEF-1 affected porcine teat number trait and could be used in breeding strategies to accelerate porcine teat number trait improvement of indigenous pigs breeds through molecular marker assisted selection.