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Monitoring and control of wind-induced vibrations of hanger ropes of a suspension bridge
Xu G. Hua,Zheng Q. Chen,Xu Lei,Qin Wen,Hua W. Niu 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.23 No.6
In August 2012, during the passage of the typhoon Haikui (1211), large amplitude vibrations were observed on long hangers of the Xihoumen suspension Bridge, which destroyed a few viscoelastic dampers originally installed to connect a pair of hanger ropes transversely. The purpose of this study is to identify the cause of vibration and to develop countermeasures against vibration. Field measurements have been conducted in order to correlate the wind and vibration characteristics of hangers. Furthermore, a replica aeroelastic model of prototype hangers consisting of four parallel ropes was used to study the aeroelastic behavior of hanger ropes and to examine the effect of the rigid spacers on vibration mitigation. It is shown that the downstream hanger rope experiences the most violent elliptical vibration for certain wind direction, and the vibration is mainly attributed to wake interference of parallel hanger ropes. Based on wind tunnel tests and field validation, it is confirmed that four rigid spacers placed vertically at equal intervals are sufficient to suppress the wake-induced vibrations. Since the deployment of spacers on hangers, server hanger vibrations and clash of hanger ropes are never observed.
Luciferase Assay to Screen Tumour-specific Promoters in Lung Cancer
Xu, Rong,Guo, Long-Jiang,Xin, Jun,Li, Wen-Mao,Gao, Yan,Zheng, You-Xian,Guo, You-Hong,Lin, Yang-Jun,Xie, Yong-Hua,Wu, Ya-Qing,Xu, Rui-An Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11
Objective: Specific promoters could improve efficiency and ensure the safety of gene therapy. The aim of our study was to screen examples for lung cancer. Methods: The firefly luciferase gene was used as a reporter, and promoters based on serum markers of lung cancer were cloned. The activity and specificity of seven promoters, comprising CEACAM5 (carcinoembryonic antigen, CEA), GRP (Gastrin-Releasing Peptide), KRT19 (cytokeratin 19, KRT), SFTPB (surfactant protein B, SP-B), SERPINB3 (Squamous Cell Carcinoma Antigen, SCCA), SELP (Selectin P, Granule Membrane Protein 140kDa, Antigen CD62, GMP) and DKK1 (Dickkopf-1) promoters were compared in lung cancer cells to obtain cancer-specific examples with strong activity. Results: The CEACAM5, DKK1, GRP, SELP, KRT19, SERPINB3 and SFTPB promoters were cloned. Furthermore, we successfully constructed recombinant vector pGL-CEACAM5 (DKK1, GRP, SELP, KRT19, SERPINB3 and SFTPB) contained the target gene. After cells were transfectedwith recombinant plasmids, we found that the order of promoter activity from high to low was SERPINB3, DKK1, SFTPB, KRT19, CEACAM5, SELP and GRP and the order for promoters regarding specificity and high potential were SERPINB3, DKK1, SELP, SFTPB, CEACAM5, KRT19 and GRP. Conclusion: The approach adopted is feasible to screen for new tumour specific promoters with biomarkers. In addition, the screened lung-specific promoters might have potential for use in lung cancer targeted gene therapy research.
Refolding Behavior of Urea-Induced Denaturation Collagen
Xu Wei,Yanqiu Zhao,Jingjing Zheng,Qin Cao,Sheng Li,Lang He,Benmei Wei,Juntao Zhang,Chengzhi Xu,Haibo Wang 한국고분자학회 2021 Macromolecular Research Vol.29 No.6
Exploration of the denaturation and refolding of natural collagen is important for the application of collagen and its denatured products. In this study, using urea as a denaturant, we prepared a denatured natural collagen product and analyzed its structural changes. The denaturation treatment severely destroyed the triple helix conformation of collagen, but had no significant effect on the primary structure of its α chains or the covalent cross-linking between α chains. Next, we observed the refolding behavior of the denatured collagen by removing urea through dialysis. We found that the denatured collagen products from different sources (grass carp skin, bovine tendon) all showed a reconstruction of the triple helix conformation up to 60-75% of the value of natural collagen during the refolding process. The telopeptide did not significantly promote triple helix reconstruction. In conclusion, the reconstruction of the α chains did not perfectly occur in a “head-to-head, tail-to-tail” manner in refolded collagen, as each α chain was participating in the reconstruction of multiple triple helix domains. The refolded collagen still had weak self-assembly ability and formed a unique network-like structure containing small interlaced and closely combined fibers, which shows favorable cell compatibility and potential applications.
Zheng, Xu,Lee, Kum Hee,Liu, Hongguang,Park, So-Young,Yoon, Seung Soo,Lee, Jin Yong,Kim, Yang-Gyun Elsevier 2016 Sensors and actuators. B Chemical Vol.222 No.-
<P><B>Abstract</B></P> <P>A new bis(pyridine-2-ylmethyl)amine derivative (<B>1</B>) was synthesized as a colorimetric and fluorescent chemosensor for metal ions. Experimental results indicate that <B>1</B> displays significant colorimetric and fluorescent changes upon binding of Cu<SUP>2+</SUP>. Since <B>1</B> has a high water solubility as well as good cell-permeability, it successfully applied to detect the presence of Cu<SUP>2+</SUP> ion in HepG2 cells in culture medium. Thus, <B>1</B> can be used as a potential Cu<SUP>2+</SUP> chemosensor in aqueous solution and mammalian cells. Further, the fluorescence behavior of <B>1</B> upon Cu<SUP>2+</SUP> binding was well explained by our quantum calculation based on electronic structure.</P>
Corroded pipeline failure analysis using artificial neural network scheme
Xu, Wen-Zheng,Li, Chun Bao,Choung, Joonmo,Lee, Jae-Myung Elsevier Applied Science 2017 Advances in engineering software Vol.112 No.-
<P><B>Abstract</B></P> <P>Corrosion defects occur very often on the internal and external surfaces of pipelines, which may result in a serious threat to the integrity of the pipelines. Numerous studies investigated failure behavior of corroded pipelines with single corrosion defects. However, few studies focus on interacting corrosion defects. Interacting defects are defined as defects with certain proximity that interact to reduce the overall strength of a pipeline. In the present study, the failure behavior of pipelines with interacting corrosion defects was studied using a finite element method, and then a solution was proposed to predict burst pressure using an artificial neural network. The solution was validated by experimental results in previous studies and compared with other existing assessment solutions to prove its applicability and efficiency.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The failure behavior of pipelines with interacting corrosion defects was studied using FE method. </LI> <LI> A series of models were created for the sensitive study of the various parameters. </LI> <LI> A solution was proposed to predict burst pressure using an artificial neural network (ANN). </LI> <LI> The solution was validated by comparing with experimental results and existing codes. </LI> </UL> </P>
Xu, Lu-Wei,Qian, Ming,Jia, Rui-Peng,Xu, Zheng,Wu, Jian-Ping,Li, Wen-Cheng,Huang, Wen-Bin,Chen, Xing-Guo Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4
The aim of this study was to investigate the expression and significance of microsomal prostaglandin synthase-1 (mPGES-1) and Beclin-1 in the development of prostate cancer (PCa). Immunohistochemistry was performed on paraffin-embedded sections with rabbit polyclonal against mPGES-1 and Beclin-1 in 40 PCa, 40 benign prostatic hyperplasia (BPH) and 10 normal prostate specimens for this purpose. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for mRNA expression of mPGES-1 and Beclin-1, while MTT assays were used to ascertain the best working concentration of the mPGES-1 inhibitor (CAY10526). The effect of CAY10526 treatment on expression of Beclin-1 in DU-145 cells was studied using Western blot analysis. Localization of Beclin-1 and mPGES-1 was in endochylema. Significant differences in expression was noted among PCa, BPH and normal issues (P<0.05). Beclin-1 expression inversely correlated with mPGES-1 expression in PCa tissue (P<0.05). CAY10526 could significantly block mPGES-1 expression and the proliferation of DU-145 cells (P<0.05), while increasing Beclin-1 levels (P<0.05). Overexpression of mPGES-1 could decrease the autophagic PCa cell death. Inhibiting the expression of mPGES-1 may lead to DU-145 cell death and up-regulation of Beclin-1. The results suggest that inhibition of mPGES-1 may have therapeutic potential for PCa in the future.
Carbon nanomaterials for advanced lithium sulfur batteries
Xu, Zheng-Long,Kim, Jang-Kyo,Kang, Kisuk Elsevier 2018 NANO TODAY Vol.19 No.-
<P><B>Abstract</B></P> <P>Taking advantage of a high theoretical energy density of 2567 Wh kg<SUP>-1</SUP>, lithium sulfur batteries (LSBs) have been considered promising candidates for next-generation energy storage systems. Nevertheless, challenging issues involving both sulfur cathode and lithium anode hinder their practical applications, which are followed by the extensive research efforts to resolve them. A wide variety of carbon nanomaterials with different characteristics has played an important role in enhancing the performance of LSBs <I>via</I> immobilizing sulfur in cathodes, accommodating the volume expansion of sulfur, enhancing the reaction kinetics and stabilizing lithium anodes. This report overviews the state-of-the-art progress in designing and fabricating nanocarbon for advanced LSBs with particular focuses on the correlations among porosity, electrical conductivity and surface chemistry as some of the most critical factors. More importantly, statistical analysis of electrochemical performance of batteries collected from literatures allows us to identify substantial disparities between the current achievements and the requirements for real-world applications. In an effort to bridge this gap, we highlight recent advances in the design of LSBs with improved sulfur loading, enhanced charge transfer and minimized electrolyte/sulfur ratio. Conclusions and perspectives for future development of nanocarbon in LSBs are proposed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The fundamentals of LSBs, carbon nanomaterials and sulfur/carbon cathodes are discussed. </LI> <LI> Design principles of nanocarbon to overcome the intrinsic challenges of LSBs are summarized. </LI> <LI> The gap between the current achievements and the practical LSBs in real-market is bridged. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Xu, Zheng-Yi,Kim, Soo Youn,Hyeon, Do Young,Kim, Dae Heon,Dong, Ting,Park, Youngmin,Jin, Jing Bo,Joo, Se-Hwan,Kim, Seong-Ki,Hong, Jong Chan,Hwang, Daehee,Hwang, Inhwan American Society of Plant Biologists 2013 The Plant cell Vol.25 No.11
<P>This work examines the role of the NAC transcription factor ANAC096, finding that ANAC096 interacts with specific bZIP transcription factors to globally affect abscisic acid–responsive transcription during osmotic and drought stresses.</P>