Evaluation on bridge dynamic properties and VIV performance based on wind tunnel test and field measurement

Yongxin Yang,Tingting Ma,Yaojun Ge 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.6

Full scale measurement on the structural dynamic characteristics and Vortex-induced Vibrations (VIV) of a long-span suspension bridge with a central span of 1650 m were conducted. Different Finite Element (FE) modeling principles for the separated twin-box girder were compared and evaluated with the field vibration test results, and the double-spine model was determined to be the best simulation model, but certain modification still needs to be made which will affect the basic modeling parameters and the dynamic response prediction values of corresponding wind tunnel tests. Based on the FE modal analysis results, small-scaled and large-scaled sectional model tests were both carried out to investigate the VIV responses, and probable Reynolds Number effects or scale effect on VIV responses were presented. Based on the observed VIV modes in the field measurement, the VIV results obtained from sectional model tests were converted into those of the three-dimensional (3D) full-scale bridge and subsequently compared with field measurement results. It is indicated that the large-scaled sectional model test can probably provide a reasonable and effective prediction on VIV response.

Evaluation on bridge dynamic properties and VIV performance based on wind tunnel test and field measurement

Yang, Yongxin,Ma, Tingting,Ge, Yaojun Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.6

Full scale measurement on the structural dynamic characteristics and Vortex-induced Vibrations (VIV) of a long-span suspension bridge with a central span of 1650 m were conducted. Different Finite Element (FE) modeling principles for the separated twin-box girder were compared and evaluated with the field vibration test results, and the double-spine model was determined to be the best simulation model, but certain modification still needs to be made which will affect the basic modeling parameters and the dynamic response prediction values of corresponding wind tunnel tests. Based on the FE modal analysis results, small-scaled and large-scaled sectional model tests were both carried out to investigate the VIV responses, and probable Reynolds Number effects or scale effect on VIV responses were presented. Based on the observed VIV modes in the field measurement, the VIV results obtained from sectional model tests were converted into those of the three-dimensional (3D) full-scale bridge and subsequently compared with field measurement results. It is indicated that the large-scaled sectional model test can probably provide a reasonable and effective prediction on VIV response.

A Method for Generating Malware Countermeasure Samples Based on Pixel Attention Mechanism

Xiangyu Ma,Yuntao Zhao,Yongxin Feng,Yutao Hu 한국인터넷정보학회 2024 KSII Transactions on Internet and Information Syst Vol.18 No.2

Studies have shown that malware has become a primary means of attacking the Internet. Therefore, adversarial samples have become a vital breakthrough point for studying malware. By studying adversarial samples, we can gain insights into the behavior and characteristics of malware, evaluate the performance of existing detectors in the face of deceptive samples, and help to discover vulnerabilities and improve detection methods for better performance. However, existing adversarial sample generation methods still need help regarding escape effectiveness and mobility. For instance, researchers have attempted to incorporate perturbation methods like Fast Gradient Sign Method (FGSM), Projected Gradient Descent (PGD), and others into adversarial samples to obfuscate detectors. However, these methods are only effective in specific environments and yield limited evasion effectiveness. To solve the above problems, this paper proposes a malware adversarial sample generation method (PixGAN) based on the pixel attention mechanism, which aims to improve adversarial samples' escape effect and mobility. The method transforms malware into grey-scale images and introduces the pixel attention mechanism in the Deep Convolution Generative Adversarial Networks (DCGAN) model to weigh the critical pixels in the grey-scale map, which improves the modeling ability of the generator and discriminator, thus enhancing the escape effect and mobility of the adversarial samples. The escape rate (ASR) is used as an evaluation index of the quality of the adversarial samples. The experimental results show that the adversarial samples generated by PixGAN achieve escape rates of 97%, 94%, 35%, 39%, and 43% on the Random Forest (RF), Support Vector Machine (SVM), Convolutional Neural Network (CNN), Convolutional Neural Network and Recurrent Neural Network (CNN_RNN), and Convolutional Neural Network and Long Short Term Memory (CNN_LSTM) algorithmic detectors, respectively.

H2 Metabolism revealed by metagenomic analysis of subglacial sediment from East Antarctica

Zhifeng Yang,Yu Zhang,Yongxin Lv,Wenkai Yan,Xiang Xiao,Bo Sun,Hongmei Ma 한국미생물학회 2019 The journal of microbiology Vol.57 No.12

Subglacial ecosystems harbor diverse chemoautotrophic microbial communities in areas with limited organic carbon, and lithological H2 produced during glacial erosion has been considered an important energy source in these ecosystems. To verify the H2-utilizing potential there and to identify the related energy-converting metabolic mechanisms of these communities, we performed metagenomic analysis on subglacial sediment samples from East Antarctica with and without H2 supplementation. Genes coding for several [NiFe]- hydrogenases were identified in raw sediment and were enriched after H2 incubation. All genes in the dissimilatory nitrate reduction and denitrification pathways were detected in the subglacial community, and the genes coding for these pathways became enriched after H2 was supplied. Similarly, genes transcribing key enzymes in the Calvin cycle were detected in raw sediment and were also enriched. Moreover, key genes involved in H2 oxidization, nitrate reduction, oxidative phosphorylation, and the Calvin cycle were identified within one metagenome-assembled genome belonging to a Polaromonas sp. As suggested by our results, the microbial community in the subglacial environment we investigated consisted of chemoautotrophic populations supported by H2 oxidation. These results further confirm the importance of H2 in the cryosphere.

Identification of two rare mutations c.1318G>A and c.6438+2T>G in a Chinese DMD family as genetic markers

Yingchuan Zhu,Lijun Yang,Tengjiao Ma,Yilu Lu,Dachang Tao,Yunqiang Liu,Yongxin Ma 한국유전학회 2020 Genes & Genomics Vol.42 No.9

Background Duchenne muscular dystrophy (DMD) is a fatal X-linked recessive disorder with no efective treatment, which underscores the importance of avoiding the birth of children with DMD by identifying pathogenic mutations and obtaining an accurate prenatal diagnosis. Objective The objective of this study was to analyze the genetic defect of a Chinese family where all male patients have died of DMD. Methods Multiplex ligation dependent probe analysis (MLPA) and next-generation sequencing (NGS) were employed to detect DMD mutations. The candidate mutations were then validated by Sanger sequencing. In vitro splicing assay was further conducted to examine the potential efect of the novel DMD splice site mutation on splicing. Results We found that two rare DMD mutations c.1318G>A and c.6438+2T>G passed from generation to generation among female carriers and they may be used as genetic markers in the Chinese DMD family. In vitro splicing assay further revealed that the novel classical splice site mutation c.6438+2T>G gave rise to a new donor splice site, which resulted in a frame shift of the transcripts and a premature termination at position 2159 in exon 45 (p.Y2144Nfs*16). Conclusion We found that two co-inherited mutations passed from generation to generation in female carriers and they may be used as genetic markers in the Chinese DMD family. Our fndings not only expanded the DMD mutation spectrum, but also provided an important basis for identifying of female carriers and avoiding the birth of afected male children in this DMD family.

Cloning and Expression Analysis of a Novel Mouse Zinc Finger Protein Gene Znf313 Abundantly Expressed in Testis

Li, Na,Sun, Huaqin,Wu, Qiaqing,Tao, Dachang,Zhang, Sizhong,Ma, Yongxin Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.2

We have cloned a novel mouse zinc finger protein gene Znf313 by rapid amplification of cDNA ends (RACE) according to the homologue of human ZNF313 gene. The cDNA is 2,163 base pairs (bp) in length and encodes a 229 amino acids (aa) protein with a $C_3HC_4$ ring finger domain and three $C_2H_2$ domains. 89% and 93% nucleotide (nt) and aa sequence identity is observed with its human homologue. Revealed by Northern blot and RT-PCR, full mRNA consists of 2.16 kb and widely expresses in tissues as a single transcript, most abundantly in heart, liver, kidney and testis. The expression of Znf313 in testis is detected in all development stages. Western blot analysis also reveals that Znf313 is expressed in the tissues. Immunohistochemical staining and subcellular localization demonstrate that Znf313 is expressed both in the cytoplasm and nucleus whereas predominantly localized in the nucleus. Present data suggests that Znf313 gene might play a fundamental role in gene transcription and regulation in organism and relates to spermatogenesis.

Unmethylated state of 5' upstream CpG islands may be necessary but not sufficient for the testis-enriched expression of ZNF230/Znf230

Yunqiang Liu,Sizhong Zhang,Dachang Tao,Yuan Yang,Yongxin Ma 한국유전학회 2014 Genes & Genomics Vol.36 No.2

The testis-enriched genes ZNF230/Znf230 arelocated on human chromosome 11p15/mouse chromosome7 near conserved imprinting control regions. Typical CpGislands (CGIs) extend from the promoter to the first exon ineach of these genes. To investigate the correlation betweenthe methylation status of the above CGIs and the expressionpatterns of the two genes, we performed bisulfitegenomic sequencing of genomic DNA from human andmouse tissues and cells. The results showed that the CGIsof ZNF230/Znf230 were completely unmethylated in allselected tissues and cells, regardless of the expressionlevels of the two genes. Further experiments using Znf230-second-exon-knockout mice to investigate the imprintingstatus of Znf230 showed that its expression was notaffected by genomic imprinting. However, an in vitromethylation assay illustrated that the methylation of theseCpG sites could repress the expression of the luciferasereporter gene. Furthermore, chromatin immunoprecipitationwith anti-Specificity protein 1 (Sp1) antibody showedthat Sp1 could bind to the CGIs in the ZNF230/Znf230gene promoter. Thus, we propose that the unmethylatedstate of ZNF230/Znf230 CGIs may be a prerequisite fortheir expression but not sufficient for their abundantexpression in the testis, and that Sp1 binding may be onefactor involved in preserving the methylation-free state ofZNF230/Znf230 CGIs.

A novel NPHS2 mutation (c.865A > G) identified in a Chinese family with steroid-resistant nephrotic syndrome alters subcellular localization of nephrin

Wu Na,Zhu Yingchuan,Jiang Wenhao,Song Yue,Yin Lan,Lu Yilu,Tao Dachang,Liu Yunqiang,Ma Yongxin 한국유전학회 2022 Genes & Genomics Vol.44 No.5

Background: NPHS2 is the causative gene of nephrotic syndrome type 2 (MIM 600995) which often clinically manifests as steroid-resistant nephrotic syndrome (SRNS). The NPHS2 gene encodes a slit diaphragm (SD) associated protein podocin. Objective: This study reported a novel disease-causing mutation of NPHS2 in a Chinese family with SRNS. We also investigated the pathogenic mechanism of the variants in this family. Method: A Chinese family with SRNS was recruited. Whole exome sequencing was performed to screen for disease-causing mutation. Sanger sequencing was used to confirm the results. In vitro functional experiments including immunoblotting, co-immunoprecipitation and double immunofluorescence staining were performed to explore the pathogenic mechanisms of mutations. Results: In this family, compound heterozygous mutations of NPHS2 (c.467dupT and c.865A > G) were identified and segregated with the disease. The maternal c.865A > G was a novel variant, leading to amino acid substitution (p.K289E). In vitro functional assays indicated that c.467dupT (p.L156FfsX11) mutant lost interaction with nephrin. Both K289E and L156FfsX11 mutants showed sharply diminished plasma membrane localization. Furthermore, abnormal distribution of podocin mutants also altered the cell membrane localization of nephrin. Conclusion: We reported a family with SRNS caused by compound heterozygous mutations of NPHS2 (c.467dupT and c.865A > G). c.865A > G (p.K289E) in NPHS2 was a novel causative variant associated with SRNS. Both variants in this family not only affected the normal cell membrane localization of podocin, but also altered the cell membrane localization of nephrin which is the major architectural protein of SD.