• 제목/요약/키워드: Li Yan

검색결과 899건 처리시간 0.026초

Experimental study on a new type of assembly bolted end-plate connection

  • Li, Shufeng;Li, Qingning;Jiang, Haotian;Zhang, Hao;Yan, Lei;Jiang, Weishan
    • Steel and Composite Structures
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    • 제26권4호
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    • pp.463-471
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    • 2018
  • The bolted end-plate beam-column connections have been widely used in steel structure and composite structure because of its excellent seismic performance. In this paper, the end-plate bolted connection is applied in the concrete structure, A new-type of fabricated beam-column connections with end-plates is presented, and steel plate hoop is used to replace stirrups in the node core area. To study the seismic behavior of the joint, seven specimens are tested by pseudo-static test. The experimental results show that the new type of assembly node has good ductility and energy dissipation capacity. Besides, under the restraint effect of the high-strength stirrup, the width of the web crack is effectively controlled. In addition, based on the analysis of the factors affecting the shear capacity of the node core area, the formula of shear capacity of the core area of the node is proposed, and the theoretical values of the formula are consistent with the experimental value.

Dynamic responses of shield tunnel structures with and without secondary lining upon impact by a derailed train

  • Yan, Qixiang;Li, Binjia;Deng, Zhixin;Li, Bin
    • Structural Engineering and Mechanics
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    • 제65권6호
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    • pp.741-750
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    • 2018
  • The aim of this study was to investigate the mechanical responses of a high-speed railway shield tunnel subjected to impact by a derailed train, with emphasis on the protective effect of the secondary lining. To do so, the extended finite element method was used to develop two numerical models of a shield tunnel including joints and joint bolts, one with a cast-in-situ concrete secondary lining and one without such a lining. The dynamic responses of these models upon impact were analyzed, with particular focus on the distribution and propagation of cracks in the lining structures and the mechanical responses of the joint bolts. The numerical results showed that placing a secondary lining significantly constricted the development of cracking in the segmental lining upon the impact load caused by a derailed train, reduced the internal forces on the joint bolts, and enhanced the safety of the segmental lining structure. The outcomes of this study can provide a numerical reference for optimizing the design of shield tunnels under accidental impact loading conditions.

Interference of Fisetin with Targets of the Nuclear Factor-κB Signal Transduction Pathway Activated by Epstein-Barr Virus Encoded Latent Membrane Protein 1

  • Li, Rong;Liang, Hong-Ying;Li, Ming-Yong;Lin, Chun-Yan;Shi, Meng-Jie;Zhang, Xiu-Juan
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권22호
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    • pp.9835-9839
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    • 2014
  • Fisetin is an effective compound extracted from lacquer which has been used in the treatment of various diseases. Preliminary data indicate that it also exerts specific anti-cancer effects. However, the manner in which fisetin regulates cancer growth remains unknown. In this study, we elucidated interference of fisetin with targets of the nuclear factor ${\kappa}B$ signal transduction pathway activated by Epstein-Barr virus encoding latent membrane protein 1 (LMP1)in nasopharyngeal carcinoma (NPC) cells, Results showed that fisetin inhibited the survival rate of CNE-LMP1 cells and NF-${\kappa}B$ activation caused by LMP1. Fisetin also suppressed nuclear translocation of NF-${\kappa}B$ (p65) and $I{\kappa}B{\alpha}$ phosphorylation, while inhibiting CyclinD1, all key targets of the NF-${\kappa}B$ signal transduction pathway. It was suggested that interference effects of fisetin with signal transduction activated by LMP1 encoded by the Epstein-Barr virus may play an important role in its anticancer potential.

Design of Concentrating System for Solar Side-pumped Slab Laser

  • Fan, Wentong;Liu, Yan;Guo, Pan;Deng, Rui;Li, Nan;Ding, Fukang;Li, Yasha;Zhou, Jun;Xie, Shiwei
    • Current Optics and Photonics
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    • 제4권1호
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    • pp.50-56
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    • 2020
  • The design of a concentration system for a solar side-pumped slab laser was investigated. The side size of the slab laser medium is 2 mm × 20 mm. Based on the principle of the edge ray, a secondary concentrating system consisting of a rectangular parabolic mirror (RPM) and a rectangular dielectric-filled compound parabolic concentrator (RDCPC) was demonstrated. The focal length of RPM is 1200 mm and the size is 734 mm × 2000 mm. The outlet size of the RDCPC is 2 mm × 20 mm. The concentration effect was analyzed by using Tracepro optical software. The results showed that the concentration efficiency reached 81.3% and the uniformity of the spot was 91.4% after optimization. This design of concentration system is of great reference value for a solar side-pumped slab laser.

Theoretical Study of the Reaction Mechanism for SiF2 Radical with HNCO

  • Hou, Li-Jie;Wu, Bo-Wan;Kong, Chao;Han, Yan-Xia;Chen, Dong-Ping;Gao, Li-Guo
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3738-3742
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    • 2013
  • The reaction mechanism of $SiF_2$ radical with HNCO has been investigated by the B3LYP method of density functional theory(DFT), while the geometries and harmonic vibration frequencies of reactants, intermediates, transition states and products have been calculated at the B3LYP/$6-311++G^{**}$ level. To obtain more precise energy result, stationary point energies were calculated at the CCSD(T)/$6-311++G^{**}$//B3LYP/$6-311++G^{**}$ level. $SiF_2+HNCO{\rightarrow}IM3{\rightarrow}TS5{\rightarrow}IM4{\rightarrow}TS6{\rightarrow}OSiF_2CNH(P3)$ was the main channel with low potential energy, $OSiF_2CNH$ was the main product. The analyses for the combining interaction between $SiF_2$ radical and HNCO with the atom-in-molecules theory (AIM) have been performed.

Mangiferin Induces Apoptosis by Regulating Bcl-2 and Bax Expression in the CNE2 Nasopharyngeal Carcinoma Cell Line

  • Pan, Li-Li;Wang, Ai-Yan;Huang, Yong-Qi;Luo, Yu;Ling, Min
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권17호
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    • pp.7065-7068
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    • 2014
  • To investigate the anti-proliferative mechanism of mangiferin in a human nasopharyngeal carcinoma cell line, CNE2 cells were incubated with different concentrations of mangiferin (12.5, 25, 50, 100, 150 and $200{\mu}M$) or with PBS as a control for 72 hours. Analyses were made of the cell cycle and apoptosis with measurement of mRNA and protein levels of two apoptosis-related genes, Bcl-2 and Bax. Flow cytometry assays showed mangiferin could inhibit CNE2 cell proliferation via G2/M arrest and induction of early apoptosis. Real time PCR and Western blotting showed the mRNA and protein level of Bcl-2 to be down-regulated, while those of Bax were upregulated, when CNE2 cells were treated with mangiferin. This investigation indicated anti-proliferation effects of mangiferin through induction of cell apoptosis regulated by Bcl-2 and Bax expression.

A New Cell Counting Method to Evaluate Anti-tumor Compound Activity

  • Wang, Xue-Jian;Zhang, Xiu-Rong;Zhang, Lei;Li, Qing-Hua;Wang, Lin;Shi, Li-Hong;Fang, Chun-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3397-3401
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    • 2014
  • Determining cell quantity is a common problem in cytology research and anti-tumor drug development. A simple and low-cost method was developed to determine monolayer and adherent-growth cell quantities. The cell nucleus is located in the cytoplasm, and is independent. Thus, the nucleus cannot make contact even if the cell density is heavy. This phenomenon is the foundation of accurate cell-nucleus recognition. The cell nucleus is easily recognizable in images after fluorescent staining because it is independent. A one-to-one relationship exists between the nucleus and the cell; therefore, this method can be used to determine the quantity of proliferating cells. Results indicated that the activity of the histone deacetylase inhibitor Z1 was effective after this method was used. The nude-mouse xenograft model also revealed the potent anti-tumor activity of Z1. This research presents a new anti-tumor-drug evaluation method.

Metabolomics Investigation of Cutaneous T Cell Lymphoma Based on UHPLC-QTOF/MS

  • Zhou, Qing-Yuan;Wang, Yue-Lin;Li, Xia;Shen, Xiao-Yan;Li, Ke-Jia;Zheng, Jie;Yu, Yun-Qiu
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권13호
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    • pp.5417-5421
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    • 2014
  • Objectives: The identification of cutaneous T cell lymphoma (CTCL) biomarkers may serve as a predictor of disease progression and treatment response. The aim of this study was to map potential biomarkers in CTCL plasma. Design and Methods: Plasma metabolic perturbations between CTCL cases and healthy individuals were investigated using metabolomics and ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS). Results: Principal component analysis (PCA) of the spectra showed clear metabolic changes between the two groups. Thirty six potential biomarkers associated with CTCL were found. Conclusions: Based on PCA, several biomarkers were determined and further identified by LC/MS/MS analysis. All of these could be potential early markers of CTCL. In addition, we established that heparin as a nticoagulant has better pre-treatment results than EDTA with the UHPLC-QTOF/MS appraoch.

Expression of Glypican-3 is Highly Associated with Pediatric Hepatoblastoma: a Systemic Analysis

  • Xiong, Xiao-Li;Qin, Huan;Yan, Su-Qi;Zhou, Li-Shan;Chen, Peng;Zhao, Dong-Chi
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권3호
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    • pp.1029-1031
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    • 2015
  • Objective: Glypican-3 (GPC3) is reported to be an oncofetal protein that is a useful diagnostic immunomarker for hepatoblastoma. However, the results are not inclusive. This study systemically investigated the association between expression of GPC3 and pediatric hepatoblastoma. Methods: Clinical studies evaluating the association were identified using a predefined search strategy. GPC3 immunohistochemistry was applied in the pathological diagnosis of hepatoblastoma using the monoclonal antibodies with formalin-fixed and paraffin-embedded specimens. Positive predictive rates for the association between expression of GPC3 and pediatric hepatoblastoma were calculated. Results: Specimens from four clinical studies which including 134 patients with pediatric hepatoblastoma tested by GPC3 immunohistochemistry were considered eligible for inclusion. Systemic analysis showed that, in all patients, pooled positive predictive rate of the association between expression of GPC3 and pediatric hepatoblastoma was 95.5% (128/134). Conclusion: This systemic analysis suggests that the expression of glypican-3 is highly associated with the diagnosis of pediatric hepatoblastoma.

Knockdown of Med19 Suppresses Proliferation and Enhances Chemo-sensitivity to Cisplatin in Non-small Cell Lung Cancer Cells

  • Wei, Ling;Wang, Xing-Wu;Sun, Ju-Jie;Lv, Li-Yan;Xie, Li;Song, Xian-Rang
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권3호
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    • pp.875-880
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    • 2015
  • Mediator 19 (Med19) is a component of the mediator complex which is a coactivator for DNA-binding factors that activate transcription via RNA polymerase II. Accumulating evidence has shown that Med19 plays important roles in cancer cell proliferation and tumorigenesis. The involvement of Med19 in sensitivity to the chemotherapeutic agent cisplatin was here investigated. We employed RNA interference to reduce Med19 expression in human non-small cell lung cancer (NSCLC) cell lines and analyzed their phenotypic changes. The results showed that after Med19 siRNA transfection, expression of Med19 mRNA and protein was dramatically reduced (p<0.05). Meanwhile, impaired growth potential, arrested cell cycle at G0/G1 phase and enhanced sensitivity to cisplatin were exhibited. Apoptosis and caspase-3 activity were increased when cells were exposed to Med19 siRNA and/or cisplatin. The present findings suggest that Med19 facilitates tumorigenic properties of NSCLC cells and knockdown of Med19 may be a rational therapeutic tool for lung cancer cisplatin sensitization.