Optimal design method for LLCL filters based on NSGA-III

Li, Baojin,Huang, Songtao,Ye, Jie,Li, Yesong,Shen, Anwen,Deng, Junli The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.5

The LLCL filter is usually used as a switching ripple suppressor since it can attenuate switching-frequency current harmonics much better than an LCL filter using lower total inductance and capacitance. However, it is more difficult to design LLCL parameters. In addition, it has a number of initial design constraints: the fundamental reactive power, the resonant frequency f_res, etc. are coupled and always contradictory, which means that designing the parameters is a Many-objective optimization problem (MaOP). The non-dominated sorting genetic algorithm-III (NSGA-III) does well in solving this kind of problem. In recent studies, the proposed methods only provide a range of parameters. Thus, obtaining certain parameters relies on experience, and using the boundary value cannot be proved optimal. However, using original NSGA-III is somewhat time-consuming for achieving specific parameters. To deal with this problem, this paper proposes a novel optimal design method for an LLCL filter based on NSGA-III with the handling of constraints. The proposed method gives a set of specific parameters and achieves a high computing efficiency. The proposed method is verified through simulations and a grid-connected inverter system based on a virtual instrument to show the effectiveness of the proposed method.

Electronic Structure and Half-metallicity of the Heusler Alloy Co2ZrGe

Songtao Li,Yang Liu,Zhi Ren,Xiaohong Zhang,Guodong Liu 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.7

The site preference, the electronic structure and the magnetic properties of Co2ZrGe have beenstudied by using first-principles calculations, and the stabilities of the Cu2MnAl-type and theHg2CuTi-type structures have been tested in this respect. The Cu2MnAltype structure is morefavorable than the Hg2CuTitype structure for the Co2ZrGe compound, and the equilibrium latticeparameter of the Cu2MnAltype Co2ZrGe alloy is 6.06 °A. The Co2ZrGe alloy is found to have anenergy gap in the minority spin direction at the Fermi level (EF ) and the majority spin band showsstrongly metallic characteristic. As a result, the Co2ZrGe alloy is predicted to be a half-metalwith 100% spin polarization of the conduction electrons at the EF . The calculated total magneticmoment is 2.00μB per unit cell, which is in line with the Slater-Pauling curve of Mt = Zt −24. TheCo atom-projected spin moment is 1.02μB, which mainly determines the total moment. Simultaneously,the Zr and the Ge atom moments are −0.08μB and 0.04μB, respectively. The Co2ZrGe alloymay be a promising material for application in future spintronics devices.

Packaging of Rift Valley fever virus pseudoviruses and establishment of a neutralization assay method

Yuetao Li,Yongkun Zhao,Cuiling Wang,Xuexing Zheng,Hualei Wang,Weiwei Gai,Hongli Jin,Feihu Yan,Boning Qiu,Yuwei Gao,Nan Li,Songtao Yang,Xianzhu Xia 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.2

Rift Valley fever (RVF) is an acute, febrile zoonotic disease that is caused by the RVF virus (RVFV). RVF is mainly prevalent on the ArabianPeninsula, the African continent, and several islands in the Indian Ocean near southeast Africa. RVFV has been classified by the WorldOrganisation for Animal Health (OIE) as a category A pathogen. To avoid biological safety concerns associated with use of the pathogen inRVFV neutralization assays, the present study investigated and established an RVFV pseudovirus-based neutralization assay. This study usedthe human immunodeficiency virus (HIV) lentiviral packaging system and RVFV structural proteins to successfully construct RVFVpseudoviruses. Electron microscopy observation and western blotting indicated that the size, structure, and shape of the packagedpseudoviruses were notably similar to those of HIV lentiviral vectors. Infection inhibition assay results showed that an antibody against RVFVinhibited the infective ability of the RVFV pseudoviruses, and an antibody neutralization assay for RVFV detection was then established. Thisstudy has successfully established a neutralization assay based on RVFV pseudoviruses and demonstrated that this method can be used toeffectively evaluate antibody neutralization.

Optimal of black anti-static AZO/Al2O3-SiO2-VxOy coatings for spacecraft stray light on high silicon aluminum alloys

Li Zhenyu,Zhou Zhihua,Wang Qun,Lu Songtao 한국물리학회 2023 Current Applied Physics Vol.55 No.-

It is still challenging to prepare an anti-static and anti-stray astigmatism coating on the high silicon aluminum alloy (>50 wt% Si, Al-50Si) for space material under extreme environments. To address these issues, the black anti-stray light coating with enhanced conductivity on the chemical etching surface of high-silicon Al-70Si alloy were successfully fabricated by the combination of plasma electrolytic oxidation (PEO) technology and deposited aluminum doped zinc oxide (AZO) transparent conductive film by magnetron sputtering technology. The microstructures, phase, elemental compositions, light absorption performance and electrical resistivity of coatings were tested and analyzed by SEM, EDS, XRD and XPS spectroscopy. The effects of process parameters including current density and AZO sputtering times on the structure, optical and electrical properties of the film layer were systematically studied. Convection through the fixation effect in the etched Al-70Si alloy porous layer promoted the internal heat and mass transfer during PEO process which is similar to previous reported mechanism of filling of cracks and pores by nanoparticles leading to the layer densification. The PEO coating had the highest absorptivity of 0.946 and it only decreased to 0.939 after AZO sputtering, at the same time the coating has the lowest resistivity of 1.04 × 107 Ω/sq, indicating excellent anti-stray light and antistatic ability. This two-step route pave the way to improve the conductivity without compromising optical properties of PEO coating on the high silicon aluminum alloy (>50 wt% Si, Al-50Si) for space material.

Glutathione disulfide sensitizes hepatocytes to TNFα-mediated cytotoxicity via IKK-β S-glutathionylation: a potential mechanism underlying non-alcoholic fatty liver disease

Xiaobing Dou,Songtao Li,Linfeng Hu,Lei Ding,Yue Ma,Wang Ma,Hui Chai,Zhenyuan Song 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Oxidative stress and TNFα are critically involved in the initiation and progression of non-alcoholic fatty liver disease (NAFLD). In this study, we investigated the effects of dysregulated glutathione homeostasis, a principal feature of oxidative stress, on TNFα-induced hepatotoxicity and its mechanistic implications in NAFLD progression. We showed that mice fed a high-fat diet (HFD) for 12 weeks developed hepatic steatosis and liver injuries, which were associated with not only TNFα overproduction but also hepatic glutathione dysregulation, characterized by GSH reduction and GSSG elevation. Moreover, consuming a HFD increased protein S-glutathionylation (protein-SSG formation) in the liver. Subsequent cell culture studies revealed that GSSG accumulation, as opposed to GSH reduction, sensitized hepatocytes to TNFα killing by reducing the TNFα-triggered NF-κB activity. GSSG prevented TNFα-induced activation of IKK-β, an upstream kinase in the NF-κB signaling pathway, by inducing IKK-β glutathionylation (IKK-β-SSG formation). In animal studies, in comparison to a control diet, HFD consumption resulted in increased hepatic IKK-β- SSG formation, leading to suppressed IKK-β activation and subsequent NF-κB suppression. Furthermore, we found that HFD consumption also led to decreased hepatic expression of glutaredoxin, a key enzyme for de-glutathionylation. Similarly, CdCl2, a chemical inhibitor of glutaredoxin, sensitized hepatocytes to TNFα-mediated cytotoxicity. In conclusion, our data suggest that GSSG is a potent and clinically relevant sensitizer for TNFα-induced hepatotoxicity in NAFLD, which represents a potential therapeutic target for NAFLD.

In silico identification and computational characterization of endogenous small interfering RNAs from diverse grapevine tissues and stages

Xudong Zhu,Songtao Jiu,Xiaopeng Li,Kekun Zhang,Mengqi Wang,Chen Wang,Jinggui Fang 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Small interfering RNAs (siRNAs) are effectors of regulatory pathways underlying plant development, metabolism, and stress- and nutrient-signaling regulatory networks. The endogenous siRNAs are generally not conserved between plants; consequently, it is necessary and important to identify and characterize siRNAs from various plants. To address the nature and functions of siRNAs, and understand the biological roles of the huge siRNA population in grapevine (Vitis vinifera L.). The high-throughput sequencing technology was used to identify a large set of putative endogenous siRNAs from six grapevine tissues/organs. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to classify the target genes of siRNA. In total, 520,519 candidate siRNAs were identified and their expression profiles exhibited typical temporal characters during grapevine development. In addition, we identified two grapevine trans-acting siRNA (TAS) gene homologs (VvTAS3 and VvTAS4) and the derived trans-acting siRNAs (tasiRNAs) that could target grapevine auxin response factor (ARF) and myeloblastosis (MYB) genes. Furthermore, the GO and KEGG analysis of target genes showed that most of them covered a broad range of functional categories, especially involving in disease-resistance process. The large-scale and completely genome-wide level identification and characterization of grapevine endogenous siRNAs from the diverse tissues by high throughput technology revealed the nature and functions of siRNAs in grapevine.

Automatic Subretinal Fluid Segmentation of Retinal SD-OCT Images With Neurosensory Retinal Detachment Guided by Enface Fundus Imaging

Wu, Menglin,Chen, Qiang,He, XiaoJun,Li, Ping,Fan, Wen,Yuan, SongTao,Park, Hyunjin IEEE 2018 IEEE Transactions on Biomedical Engineering Vol.65 No.1

<P>Objective: Accurate segmentation of neurosensory retinal detachment (NRD) associated subretinal fluid in spectral domain optical coherence tomography (SD-OCT) is vital for the assessment of central serous chorioretinopathy (CSC). A novel two-stage segmentation algorithm was proposed, guided by Enface fundus imaging. Methods: In the first stage, Enface fundus image was segmented using thickness map prior to detecting the fluid-associated abnormalities with diffuse boundaries. In the second stage, the locations of the abnormalities were used to restrict the spatial extent of the fluid region, and a fuzzy level set method with a spatial smoothness constraint was applied to subretinal fluid segmentation in the SD-OCT scans. Results: Experimental results from 31 retinal SD-OCT volumes with CSC demonstrate that our method can achieve a true positive volume fraction (TPVF), false positive volume fraction (FPVF), and positive predicative value (PPV) of 94.3%, 0.97%, and 93.6%, respectively, for NRD regions. Our approach can also discriminate NRD-associated subretinal fluid from subretinal pigment epithelium fluid associated with pigment epithelial detachment with a TPVF, FPVF, and PPV of 93.8%, 0.40%, and 90.5%, respectively. Conclusion: We report a fully automatic method for the segmentation of subretinal fluid. Significance: Our method shows the potential to improve clinical therapy for CSC.</P>

Low serum total testosterone level as a predictor of upgrading in low-risk prostate cancer patients after radical prostatectomy: A systematic review and meta-analysis

Shu Gan,Jian Liu,Zhiqiang Chen,Songtao Xiang,Chiming Gu,Siyi Li,Shusheng Wang 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.4

Purpose: To investigated the association between serum total testosterone and Gleason score upgrading of low-risk prostate cancer after radical prostatectomy (RP). Materials and Methods: Medline, Web of Science, Embase, and Cochrane Library databases were searched to identify eligible studies published before October 2021. Multivariate adjusted odds ratios (ORs) and associated 95% confidence intervals (CIs) were calculated using random or fixed effects models. Results: Five studies comprising 1,203 low-risk prostate cancer patients were included. The results showed that low serum total testosterone (<300 ng/dL) is associated with a high rate of Gleason score upgrading after RP (OR, 2.3; 95% CI, 1.38–3.83; p<0.001; I2, 92.2%). Notably, sensitivity and meta-regression analyses further strengthen the reliability of our results. Conclusions: Our results support the idea that low serum total testosterone is associated with a high rate of Gleason score upgrading in prostate cancer patients after RP. It is beneficial for urologist to ensure close monitoring of prostate-specific antigen levels and imaging examination when choosing non-RP treatment for low-risk prostate cancer patients.

Integrated metatranscriptome and transcriptome reveals the microbial community composition and physiological function of xylem sap on grapevine during bleeding period

Zheng Ting,Zhang Kekun,Zhu Xudong,Guan Le,Jiu Songtao,Li Xiaopeng,Mazzullah Nasim,Jia Haifeng,Fang Jinggui 한국유전학회 2019 Genes & Genomics Vol.41 No.9

Background The xylem sap of fruit trees ensures the survival during the dormant period, and its flow during the bleeding period is correlated with the start of a new life cycle. Though the simple exploration on ingredients in the sap was carried out in the early years, the specific life activities and physiology functions of the sap during bleeding period have not been reported yet and the bleeding period is still a fruit tree development period worthy of attention. Objectives In this study, the microbial community composition during bleeding period were revealed by metatranscriptome and transcriptomic data. For the first time, the microorganism genome and grape genome in xylem sap were analyzed on transcriptional level, based on which the main physiological functions of the sap were also determined. Methods The genomic RNA in the sap was isolated and sequenced. Kyoto Encyclopedia of Gene and Genome (KEGG), Evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG) and Carbohydrate-Active enzymes Database (CAZy) functional annotation were used to analysis the function of micro-organisms in xylem sap. DEGs were analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The genes responsive to biotic and abiotic stresses were finally screened by transcriptome screening, stress data analysis and vitro validation experiments. Results The analysis exhibited 36,144,564 micro-related clean reads and 244,213 unigene. KEGG, eggNOG and CAZy functional annotation analysis indicated that signal transduction and material metabolism were the most important function of xylem sap. DEGs analysis were mainly about disease resistance, carbon source metabolism and hormone signal transduction, especially in P3 vs P1, enriched in the plant-pathogen interaction pathway. Analysis on grape genome information revealed xylem sap had little RNA with weak life activity. Metabolic pathways, biosynthesis of secondary metabolites, plant hormone signal transduction and plant-pathogen interaction were the four pathways with the largest number of enriched genes. Moreover, 16 genes responsive to biotic and abiotic stresses were screened out. Conclusion Promoting plant growth and resisting pathogens were the most important function of xylem sap during the bleeding period, and the function of microbial community were closely related to microorganisms growth and disease resistance. The 16 stress-related genes might be used for the future grape resistance research.