The Impact Force of Large Boulders with Irregular Shape in Flash Flood and Debris Flow

Guang-Wu Si,Xiao-Qing Chen,Jian-Gang Chen,Jin-Bo Tang,Wan-Yu Zhao,Ke Jin 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.10

The impact force of large boulders carried by flash floods and debris flows is one of the main causes of structural damage. The elastoplastic modification model of the impact force was derived, and it was found that the impact force was significantly affected by large boulders with irregular shapes. However, a large boulder with an irregular shape is often simplified as an isovolumetric sphere or ellipsoid, which may lead to inaccurate calculation of the impact force. In this paper, a method to obtain the irregular shape of a large boulder in the field is proposed by combining field investigation, image processing, and graphic analysis. The irregular shape is described by a nonuniform rational B-spline (NURBS) curve. The curvature radii corresponding to the potential impact contact points on the surface of a large boulder, which can reflect the influence of the irregular shape, are extracted according to the concavity and convexity analysis. The results demonstrate that NURBS curves can describe irregular shapes both conveniently and accurately. The impact force was corrected by the elastic–plastic model, the impact force increased with increasing curvature radius, and the increase ratio of the impact force gradually decreased with increasing velocity. Compared with the isovolumetric sphere model and ellipsoid model, the impact force calculated by the ellipsoid model is closer to the results obtained in this paper. The reduction factor of the impact force is 0.03 − 0.16, which first increases significantly and then linearly increases with increasing curvature radius. In addition, the reduction factor of the impact force initially exhibits a significant decline with increasing velocity and then gradually stabilises. To simplify parameter selection, we suggest using the maximum curvature radius in the ellipsoid model as the calculation parameter in calculating the impact force of large boulders.

Identification of a Novel Human Zinc Finger Gene, ZNF438, with Transcription Inhibition Activity

( Zhao Min Zhong ),( Bo Wan ),( Yun Qiu ),( Jun Ni ),( Wen Wen Tang ),( Xin Ya Chen ),( Yun Yang ),( Su Qin Shen ),( Ying Wang ),( Mei Rong Bai ),( Qing Yu Lang ),( Long Yu ) 생화학분자생물학회 2007 BMB Reports Vol.40 No.4

The Application of Si And Se Fertilizers for Mitigation of Cd Accumulation in Rice

Zhe Chen,Ye-Tao Tang,Rong-Liang Qiu,Bo-Qing Tie 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Seismic Response of Resilient Steel Frame with Self-Centering SMA Brace

Shujun Hu,Liqing Chang,Bo Zhang,Sizhi Zeng,Fenghua Tang,Qing Zhi 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.6

An innovative self-centering shape memory alloy (SMA) brace aiming at improving the seismic performance and self-centering capacity of steel frame structures is proposed in this paper. A series of cyclic loading tests with six self-centering SMA brace (SC-SMAB) specimens was carried out to investigate the effects of SMA area, bolt torque and initial SMA force on the hysteresis curves, energy dissipation and self-centering capacity. In addition, based on the experimental results, a numerical model of SC-SMAB with the improved Graesser and Bouc–Wen model was established and validated. Three different single-bay plan configurations of 9 storey steel frames including bare steel frame (BSF), steel frame with slip braces (SF-SB) and steel frame with SC-SMABs (SF-SCB) were analyzed to evaluate the seismic response. The test results show that the SC-SMAB with the bolt torque of 10 N M and initial SMA force of 5 kN has the maximum bearing force and self-centering capacity ratio. The established numerical model can accurately predict the seismic performance of the SC-SMAB. The inter-story drift ratio, roof displacement and roof acceleration of SF-SCB are lower than those of the BSF and SF-SB evidently, which decrease by 62.21%, 29.46% and 28.36% respectively from BSF. The hysteresis curve of SC-SMAB in the steel frame has nearly ideal flag-shape with high bearing force, good energy dissipation capacity, small residual deformation and outstanding re-centering capacity.

Contact toxicity and transcriptomic analysis of terpinen-4-ol exposure in Tribolium castaneum

Shan-shan Gao,Yong-lei Zhang,Kun-peng Zhang,Wang Xing-yun,Qing-bo Tang,Yuan-chen Zhang 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

The terpene, terpinen-4-ol (T4ol), exhibits contact toxicity in Tribolium castaneum. However, the molecular mechanisms underlying this toxicity have not been elucidated. This study examined changes in the expression of four classic enzymes after exposure of T. castaneum to T4ol. Acetylcholinesterase and glutathione S-transferase activities were markedly inhibited after exposure to T4ol, while that of the detoxifying enzyme cytochrome oxidase P450 increased markedly. Carboxylesterase activity did not show significant changes. Furthermore, RNA sequencing revealed 260 differentially expressed genes (DEG) between the T4ol-treated and control samples, and qRT-PCR was used to validate the RNA-Seq data. The Gene Ontology analysis classified the DEGs into 36 functional groups, including the immune system processes, response to stimulus, and developmental processes. T4ol altered the response to stimulus and the immune system process of beetles by inducing the expression of the genes Stabilin-1, Attacin 1, and Defensin 1. Furthermore, the DEGs receptor tyrosine kinase Torso-like protein (RTKTsl), Frizzled 4 (Fz4), Protein Wnt-5b, Ecdysone-induced protein 78C (E78), Zinc finger protein GLIS1 (ZFPGLIS1) were classified as participating in beetle development, and Fz4 and Protein Wnt-5b also mapped to the Wnt signaling pathway. This indicated that pathways associated with development are inhibited after exposure to T4ol. T4ol also induced CYP9Z6/GSTs7 overexpression, and RNAi targeting these genes significantly increased larvae mortality on T4ol exposure, supporting the participation of CYP9Z6/GSTs7 in the response to T4ol in T. castaneum. The results of this study will facilitate understanding of the toxic mechanisms of T4ol and provide a basis for controlling the pests of stored products.

Combination of Tumor Volume and Epstein-Barr Virus DNA Improved Prognostic Stratification of Stage II Nasopharyngeal Carcinoma in the Intensity Modulated Radiotherapy Era: A Large-Scale Cohort Study

Qiu-Yan Chen,Shao-Yan Guo,Lin-Quan Tang,Tong-Yu Lu,Bo-Lin Chen,Qi-Yu Zhong,Meng-Sha Zou,Qing-Nan Tang,Wen-Hui Chen,Shan-Shan Guo,Li-Ting Liu,Yang Li,Ling Guo,Hao-Yuan Mo,Rui Sun,Dong-Hua Luo,Chong Zha 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose Little is known about combination of the circulating Epstein-Barr viral (EBV) DNA and tumor volume in prognosis of stage II nasopharyngeal carcinoma (NPC) patients in the intensity modulated radiotherapy (IMRT) era. We conducted this cohort study to evaluate the prognostic values of combining these two factors. Materials and Methods By Kaplan-Meier, we compare the differences of survival curves between 385 patients with different EBV DNA or tumor volume levels, or with the combination of two biomarkers mentioned above. Results Gross tumor volume of cervical lymph nodes (GTVnd, p < 0.001) and total tumor volume (GTVtotal, p < 0.001) were both closely related to pretreatment EBV DNA, while gross tumor volume of nasopharynx (GTVnx, p=0.047) was weakly related to EBV DNA. EBV DNA was significantly correlated with progress-free survival (PFS, p=0.005), locoregional-free survival (LRFS, p=0.039), and distant metastasis-free survival (DMFS, p=0.017), while GTVtotal, regardless of GTVnx and GTVnd, had a significant correlation with PFS and LRFS. The p-values of GTVtotal for PFS and LRFS were 0.008 and 0.001, respectively. According to GTVtotal and pretreatment EBV DNA level, patients were divided into a low-risk group (EBV DNA 0 copy/mL, GTVtotal < 30 cm3; EBV DNA 0 copy/mL, GTVtotal  30 cm3; or EBV DNA > 0 copy/mL, GTVtotal < 30 cm3) and a high-risk group (EBV DNA > 0 copy/mL, GTVtotal  30 cm3). When patients in the low-risk group were compared with those in the high-risk group, 3-year PFS (p=0.003), LRFS (p=0.010), and DMFS (p=0.031) rates were statistically significant. Conclusion Pretreatment plasma EBV DNA and tumor volume were both closely correlated with prognosis of stage II NPC patients in the IMRT era. Combination of EBV DNA and tumor volume can refine prognosis and indicate for clinical therapy.

The Role of Macrophage Migration Inhibitory Factor (MIF) in Asthmatic Airway Remodeling

Li Ruyi,Wang Feiyun,Wei Jianghong,Lin Yun,Tang Guofang,Rao Lizong,Ma Libing,Xu Qing,Wu Jingjie,Lv Qian,Zhou Rui,Lei Huiren,Zhao Xueqiang,Yao Dong,Xiao Bo,Huang Haiming,Zhang Jiange,Mo Biwen 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.1

Purpose: Recent studies have demonstrated that macrophage migration inhibitory factor (MIF) is of importance in asthmatic inflammation. The role of MIF in modulating airway remodeling has not yet been thoroughly elucidated to date. In the present study, we hypothesized that MIF promoted airway remodeling by intensifying airway smooth muscle cell (ASMC) autophagy and explored the specific mechanisms. Methods: MIF knockdown in the lung tissues of C57BL/6 mice was conducted by instilling intratracheally adeno-associated virus (AAV) vectors (MIF-mutant AAV9) into mouse lung tissues. Mice genetically deficient in the autophagy marker ATG5 (ATG5+/−) was used to detect the role of autophagy in ovalbumin (OVA)-asthmatic murine models. Moreover, to block the expression of MIF and CD74 in vitro models, inhibitors, antibodies and lentivirus transfection techniques were employed. Results: First, MIF knockdown in the lung tissues of mice showed markedly reduced airway remodeling in OVA murine mice models. Secondly, ASMC autophagy was increased in the OVA-challenged models. Mice genetically deficient in the autophagy marker ATG5 (ATG5+/−) that were primed and challenged with OVA showed lower airway remodeling than genetically wild-type asthmatic mice. Thirdly, MIF can induce ASMC autophagy in vitro. Moreover, the cellular source of MIF which promoted ASMC autophagy was macrophages. Finally, MIF promoted ASMC autophagy in a CD74-dependent manner. Conclusions: MIF can increase asthmatic airway remodeling by enhancing ASMC autophagy. Macrophage-derived MIF can promote ASMC autophagy by targeting CD74.