Effect of cover cracking on reliability of corroded reinforced concrete structures

Hua-Peng Chen,Jaya Nepal 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.20 No.5

The reliability of reinforced concrete structures is frequently compromised by the deterioration caused by reinforcement corrosion. Evaluating the effect caused by reinforcement corrosion on structural behaviour of corrosion damaged concrete structures is essential for effective and reliable infrastructure management. In lifecycle management of corrosion affected reinforced concrete structures, it is difficult to correctly assess the lifecycle performance due to the uncertainties associated with structural resistance deterioration. This paper presents a stochastic deterioration modelling approach to evaluate the performance deterioration of corroded concrete structures during their service life. The flexural strength deterioration is analytically predicted on the basis of bond strength evolution caused by reinforcement corrosion, which is examined by the experimental and field data available. An assessment criterion is defined to evaluate the flexural strength deterioration for the time-dependent reliability analysis. The results from the worked examples show that the proposed approach is capable of evaluating the structural reliability of corrosion damaged concrete structures.

3,7-Dihydroxy-2,4,6-trimethoxyphenanthrene, A New Phenanthrene from Bulbophyllum Odoratissimum

Chen, Ye-Gao,Xu, Jun-Ju,Yu, Hong,Qing, Chen,Zhang, Yan-Li,Liu, Ying,Wang, Ji-Hua Korean Chemical Society 2007 대한화학회지 Vol.51 No.4

Efficient stereoselective synthesis of α,β-Unsaturated acids, α-Cyanoacrylonitriles and α-Cyanoacrylates has been carried out in the presence of NaHSO4·SiO2 under solvent?free conditions with an E-geometry. A new phenanthrene derivative 3,7-dihydroxy-2,4,6-trimethoxyphenanthrene was isolated from the all plant of Bulbophyllum odoratissimum, and its structure was elucidated by extensive spectral studies and chemical transformation. The compound displayed cytotoxicity against the growth of human leukemia cell lines K562 and HL-60, human lung adenocarcinoma A549, human hepatoma BEL-7402 and human stomach cancer cell lines SGC-7901 with IC50 values of 14.23, 10.02, 3.42, 15.36 and 1.13 mg/ml respectively.

Digital Transformation, Manipulation of Asset Evaluation and M&A Performance: Discussion on the Intermediary Effect of Internal Control

Chen Chen,Hee-Jung Lee,Nan Hui,Xue-Hua Qian 강원대학교 경영경제연구소 2023 Asia-Pacific Journal of Business Vol.14 No.1

Purpose - The purpose of this study was to examine the internal relevance between digital transformation, manipulation of asset evaluation and corporate M&A performance and further explores the impact path of manipulation of asset valuation on corporate M&A performance. Design/methodology/approach - This study based on the financial data of A-share listed companies in Shanghai and Shenzhen Stock Exchanges from 2013 to 2021. Findings - First, manipulation of asset evaluation is negatively correlated with M&A performance. Second, Digital transformation significantly weakens the negative correlation between manipulation of asset evaluation and corporate M&A performance. Third, The effectiveness of internal control plays a partially intermediary role in the process of manipulation of asset evaluation affecting M&A performance. Research implications or Originality - Enriching the existing literature on the subject, the study can also provide useful reference for improving the performance of corporate mergers and acquisitions, regulating asset valuation, promoting the digital transformation of enterprises and improving internal control mechanisms, with both theoretical and practical implications.

On the Feasibility of Interference Alignment in the Cellular Network

( Hua Chen ),( Shan Wu ),( Ping Hu ),( Zhudi Xu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.11

In this paper, we investigate the feasibility of interference alignment(IA) in signal space in the scenario of multiple cell and multiple user cellular networks, as the feasibility issue is closely related to the solvability of a multivariate polynomial system, we give the mathematical analysis to support the constraint condition obtained from the polynomial equations with the tools of algebraic geometry, and a new distribute IA algorithm is also provided to verify the accessibility of the constraint condition for symmetric system in this paper. Simulation results illustrate that the accessibility of the constraint condition is hold if and only if the degree of freedom(DoF) of each user can be divided by both the transmit and receive antenna numbers.

Overexpression of RUNX3 Inhibits Malignant Behaviour of Eca109 Cells in Vitro and Vivo

Chen, Hua-Xia,Wang, Shuai,Wang, Zhou,Zhang, Zhi-Ping,Shi, Shan-Shan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene whose reduced expression may play an important role in the development and progression of esophageal squamous cell cancer (ESCC). The aim of this study was to investigate the clinical relevance of RUNX3 in ESCC patients and effects of overexpression on biological behaviour of Eca109 cells in vitro and in vivo. Immunohistochemistry was performed to detect the clinical relevance of RUNX3 and lymph node metastasis in 80 ESCC tissues and 40 non-cancerous tissues using the SP method. RT-PCR and Western blotting were applied to assess the RUNX3 level and verify the Eca109 cell line with stable overexpression. Localization of RUNX3 proteins was performed by cell immunofluorescence. CCK-8 and Scrape motility assays were used to determine proliferation and migration and the TUNEL assay to analyze cell apoptosis. Invasive potential was assessed in cell transwell invasion experiments. In nude mice, tumorigenesis in vivo was determined. Results showed decreased expression of RUNX3 in esophageal tissue to be significantly related to lymph node metastasis (LNM) (P<0.01). In addition, construction of a recombinant lentiviral vector and transfection into the human ESCC cell line Eca109 demonstrated that overexpression could inhibit cell proliferation, migration and invasion, and induce apoptosis. The in vivo experiments in mice showed tumorigenicity and invasiveness to be significantly reduced. Taken together, our studies indicate that underexpression of RUNX3 in human ESCC tissue is significantly correlated with progression. Restoration of RUNX3 expression significantly inhibits ESCC cells proliferation, migration, invasion and tumorigenesis.

Effects of processing method on the pharmacokinetics and tissue distribution of orally administered ginseng

Chen, Jianbo,Li, Meijia,Chen, Lixue,Wang, Yufang,Li, Shanshan,Zhang, Yuwei,Zhang, Lei,Song, Mingjie,Liu, Chang,Hua, Mei,Sun, Yinshi The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.1

Background: The use of different methods for the processing of ginseng can result in alterations in its medicinal properties and efficacy. White ginseng (WG), frozen ginseng (FG), and red ginseng (RG) are produced using different methods. WG, FG, and RG possess different pharmacological properties. Methods: WG, FG, and RG extracts and pure ginsenosides were administered to rats to study the pharmacokinetics and tissue distribution characteristics of the following ginsenosides-DRg1, Re, Rb1, and Rd. The concentrations of the ginsenosides in the plasma and tissues were determined using UPLC-MS/MS. Results: The rate and extent of absorption of Rg1, Re, Rb1, and Rd appeared to be affected by the different methods used in processing the ginseng samples. The areas under the plasma drug concentration-time curves (AUCs) of Rg1, Re, Rb1, and Rd were significantly higher than those of the pure ginsenosides. In addition, the AUCs of Rg1, Re, Rb1, and Rd were different for WG, FG, and RG. The amounts of Rg1, Re, Rd, and Rb1 were significantly (p < 0.05) higher in the tissues than those of the pure ginsenosides. The amounts of Re, Rb1, and Rd from the RG extract were significantly higher than those from the WG and FG extracts in the heart, lungs, and kidneys of the rats. Conclusion: Our results show that the use of different methods to process ginseng might affect the pharmacokinetics and oral bioavailability of ginseng as well as the tissue concentrations of Rg1, Re, Rd, and Rb1.

Dynamic characteristics of multiple inerter based dampers for suppressing harmonically forced oscillations

Hua-ting Chen,Shaomin Jia,Xuefeng He 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.6

Based on the ball-screw mechanism, a tuned viscous mass damper (TVMD) has been proposed, which has functions of amplifying physical mass of the system and frequency tuning. Considering the sensitivity of a single TVMD’s effectiveness to frequency mistuning like that of the conventional tuned mass damper (TMD) and according to the concept of the conventional multiple tuned mass damper (MTMD), in the present paper, multiple tuned mass viscous dampers (MTVMD) consisting of many tuned mass dampers (TVMD) with a uniform distribution of natural frequencies are considered for attenuating undesirable vibration of a structure. The MTVMD is manufactured by keeping the stiffness and damping constant and varying the mass associated with the lead of the ball-screw type inerter element in the damper. The structure is represented by its mode-generalized system in a specific vibration mode controlled using the mode reduced-order method. Modal properties and fundamental characteristics of the MTVMD-structure system are investigated analytically with the parameters, i.e., the frequency band, the average damping ratio, the tuning frequency ratio, the total number of TVMD and the total mass ratio. It is found that there exists an optimum set of the parameters that makes the frequency response curve of the structure flattened with smaller amplitudes in a wider input frequency range. The effectiveness and robustness of the MTVMD are also discussed in comparison with those of the usual single TVMD (STVMD) and the results shows that the MTVMD is more effective and robust with the same level of total mass.

Endophytic Trichoderma gamsii YIM PH30019: a promising biocontrol agent with hyperosmolar, mycoparasitism, and antagonistic activities of induced volatile organic compounds on root-rot pathogenic fungi of Panax notoginseng

Chen, Jin-Lian,Sun, Shi-Zhong,Miao, Cui-Ping,Wu, Kai,Chen, You-Wei,Xu, Li-Hua,Guan, Hui-Lin,Zhao, Li-Xing The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.4

Background: Biocontrol agents are regarded as promising and environmental friendly approaches as agrochemicals for phytodiseases that cause serious environmental and health problems. Trichoderma species have been widely used in suppression of soil-borne pathogens. In this study, an endophytic fungus, Trichoderma gamsii YIM PH30019, from healthy Panax notoginseng root was investigated for its biocontrol potential. Methods: In vitro detached healthy roots, and pot and field experiments were used to investigate the pathogenicity and biocontrol efficacy of T. gamsii YIM PH30019 to the host plant. The antagonistic mechanisms against test phytopathogens were analyzed using dual culture, scanning electron microscopy, and volatile organic compounds (VOCs). Tolerance to chemical fertilizers was also tested in a series of concentrations. Results: The results indicated that T. gamsii YIM PH30019 was nonpathogenic to the host, presented appreciable biocontrol efficacy, and could tolerate chemical fertilizer concentrations of up to 20%. T. gamsii YIM PH30019 displayed antagonistic activities against the pathogenic fungi of P. notoginseng via production of VOCs. On the basis of gas chromatography-mass spectrometry, VOCs were identified as dimethyl disulfide, dibenzofuran, methanethiol, ketones, etc., which are effective ingredients for antagonistic activity. T. gamsii YIM PH30019 was able to improve the seedlings' emergence and protect P. notoginseng plants from soil-borne disease in the continuous cropping field tests. Conclusion: The results suggest that the endophytic fungus T. gamsii YIM PH30019 may have a good potential as a biological control agent against notoginseng phytodiseases and can provide a clue to further illuminate the interactions between Trichoderma and phytopathogens.

Time-dependent reliability analysis of coastal defences subjected to changing environments

Chen, Hua-Peng Techno-Press 2015 Structural monitoring and maintenance Vol.2 No.1

This paper presents a method for assessing the risk of wave run-up and overtopping of existing coastal defences and for analysing the probability of failure of the structures under future hydraulic conditions. The recent UK climate projections are employed in the investigations of the influence of changing environments on the long-term performance of sea defences. In order to reduce the risk of wave run-up and overtopping caused by rising sea level and to maintain the present-day allowances for wave run-up height and overtopping discharge, the future necessary increase in crest level of existing structures is investigated. Various critical failure mechanisms are considered for reliability analysis, i.e., erosion of crest by wave overtopping, failure of seaside revetment, and internal erosions within earth sea dykes. The time-dependent reliability of sea dykes is analysed to give probability of failure with time. The results for an example earth dyke section show that the necessary increase in crest level is approximately double of sea level rise to maintain the current allowances. The probability of failure for various failure modes of the earth dyke has a significant increase with time under future hydraulic conditions.

SDC4 Gene Silencing Favors Human Papillary Thyroid Carcinoma Cell Apoptosis and Inhibits Epithelial Mesenchymal Transition via Wnt/β-Catenin Pathway

Chen, Liang-Liang,Gao, Ge-Xin,Shen, Fei-Xia,Chen, Xiong,Gong, Xiao-Hua,Wu, Wen-Jun Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.9

As the most common type of endocrine malignancy, papillary thyroid cancer (PTC) accounts for 85-90% of all thyroid cancers. In this study, we presented the hypothesis that SDC4 gene silencing could effectively attenuate epithelial mesenchymal transition (EMT), and promote cell apoptosis via the $Wnt/{\beta}-catenin$ signaling pathway in human PTC cells. Bioinformatics methods were employed to screen the determined differential expression levels of SDC4 in PTC and adjacent normal samples. PTC tissues and adjacent normal tissues were prepared and their respective levels of SDC4 protein positive expression, in addition to the mRNA and protein levels of SDC4, $Wnt/{\beta}-catenin$ signaling pathway, EMT and apoptosis related genes were all detected accordingly. Flow cytometry was applied in order to detect cell cycle entry and apoptosis. Finally, analyses of PTC migration and invasion abilities were assessed by using a Transwell assay and scratch test. In PTC tissues, activated $Wnt/{\beta}-catenin$ signaling pathway, increased EMT and repressed cell apoptosis were determined. Moreover, the PTC K1 and TPC-1 cell lines exhibiting the highest SDC4 expression were selected for further experiments. In vitro experiments revealed that SDC4 gene silencing could suppress cell migration, invasion and EMT, while acting to promote the apoptosis of PTC cells by inhibiting the activation of the $Wnt/{\beta}-catenin$ signaling pathway. Besides, $si-{\beta}-catenin$ was observed to inhibit the promotion of PTC cell migration and invasion caused by SDC4 overexpression. Our study revealed that SDC4 gene silencing represses EMT, and enhances cell apoptosis by suppressing the activation of the $Wnt/{\beta}-catenin$ signaling pathway in human PTC.