• Title/Summary/Keyword: Li Ye

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Experimental study on cyclically-damaged steel-concrete composite joints subjected to fire

  • Ye, Zhongnan;Jiang, Shouchao;Heidarpour, Amin;Li, Yingchao;Li, Guoqiang
    • Steel and Composite Structures
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    • v.30 no.4
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    • pp.351-364
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    • 2019
  • Earthquake and fire are both severe disasters for building structures. Since earthquake-induced damage will weaken the structure and reduce its fire endurance, it is important to investigate the behavior of structure subjected to post-earthquake fire. In this paper, steel-concrete composite beam-to-column joints were tested under fire with pre-damage caused by cyclic loads. Beforehand, three control specimens with no pre-damage were tested to capture the static, cyclic and fire-resistant performance of intact joints. Experimental data including strain, deflection and temperature recorded at several points are presented and analyzed to quantify the influence of cyclic damage on fire resistance. It is indicated that the fire endurance of damaged joints decreased with the increase of damage level, mainly due to faster heating-up rate after cyclic damage. However, cracks induced by cyclic loading in concrete are found to mitigate the concrete spalling at elevated temperatures. Moreover, the relationship between fire resistance and damage degree is revealed from experimental results, which can be applied in fire safety design and is worthwhile for further research.

Statics variation analysis due to spatially moving of a full ocean depth autonomous underwater vehicle

  • Jiang, Yanqing;Li, Ye;Su, Yumin;Cao, Jian;Li, Yueming;Wang, Youkang;Sun, Yeyi
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.448-461
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    • 2019
  • Changes in gravity and buoyancy of a Full Ocean Depth Autonomous Underwater Vehicle (FOD-AUV) during its descending and ascending process must be considered very carefully compared with a Human Occupied Vehicle (HOV) or a Remotely Pperated Vehicle (ROV) whose activities rely on human decision. We firstly designed a two-step weight dropping pattern to achieve a high descending and ascending efficiency and a gravity-buoyancy balance at designed depth. The static equations showed that gravity acceleration, seawater density and displacement are three key aspects affecting the balance. Secondly, we try our best to analysis the gravity and buoyancy changing according to the previous known scientific information, such as anomaly of gravity acceleration, changing of seawater states. Finally, we drew conclusion that gravity changes little (no more than 0.1kgf, it is impossible to give a accurate value). A density-depth relationship at the Challenger Deep was acquired and the displacement changing of the FOD-AUV was calculated preciously.

Recent Advances in Synthetic, Industrial and Biological Applications of Violacein and Its Heterologous Production

  • Ahmed, Aqsa;Ahmad, Abdullah;Li, Renhan;AL-Ansi, Waleed;Fatima, Momal;Mushtaq, Bilal Sajid;Basharat, Samra;Li, Ye;Bai, Zhonghu
    • Journal of Microbiology and Biotechnology
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    • v.31 no.11
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    • pp.1465-1480
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    • 2021
  • Violacein, a purple pigment first isolated from a gram-negative coccobacillus Chromobacterium violaceum, has gained extensive research interest in recent years due to its huge potential in the pharmaceutic area and industry. In this review, we summarize the latest research advances concerning this pigment, which include (1) fundamental studies of its biosynthetic pathway, (2) production of violacein by native producers, apart from C. violaceum, (3) metabolic engineering for improved production in heterologous hosts such as Escherichia coli, Citrobacter freundii, Corynebacterium glutamicum, and Yarrowia lipolytica, (4) biological/pharmaceutical and industrial properties, (5) and applications in synthetic biology. Due to the intrinsic properties of violacein and the intermediates during its biosynthesis, the prospective research has huge potential to move this pigment into real clinical and industrial applications.

Numerical study on fire resistance of cyclically-damaged steel-concrete composite beam-to-column joints

  • Ye, Zhongnan;Heidarpour, Amin;Jiang, Shouchao;Li, Yingchao;Li, Guoqiang
    • Steel and Composite Structures
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    • v.43 no.5
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    • pp.673-688
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    • 2022
  • Post-earthquake fire is a major threat since most structures are designed allowing some damage during strong earthquakes, which will expose a more vulnerable structure to post-earthquake fire compared to an intact structure. A series of experimental research on steel-concrete composite beam-to-column joints subjected to fire after cyclic loading has been carried out and a clear reduction of fire resistance due to the partial damage caused by cyclic loading was observed. In this paper, by using ABAQUS a robust finite element model is developed for exploring the performance of steel-concrete composite joints in post-earthquake fire scenarios. After validation of these models with the previously conducted experimental results, a comprehensive numerical analysis is performed, allowing influential parameters affecting the post-earthquake fire behavior of the steel-concrete composite joints to be identified. Specifically, the level of pre-damage induced by cyclic loading is regraded to deteriorate mechanical and thermal properties of concrete, material properties of steel, and thickness of the fire protection layer. It is found that the ultimate temperature of the joint is affected by the load ratio while fire-resistant duration is relevant to the heating rate, both of which change due to the damage induced by the cyclic loading.

Bavachin Suppresses Alpha-Hemolysin Expression and Protects Mice from Pneumonia Infection by Staphylococcus aureus

  • Tao, Ye;Sun, Dazhong;Ren, Xinran;Zhao, Yicheng;Zhang, Hengjian;Jiang, Tao;Guan, Jiyu;Tang, Yong;Song, Wu;Li, Shuqiang;Wang, Li
    • Journal of Microbiology and Biotechnology
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    • v.32 no.10
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    • pp.1253-1261
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    • 2022
  • Staphylococcus aureus (S. aureus) infection causes dramatic harm to human health as well as to livestock development. As an important virulence factor, alpha-hemolysin (hla) is critical in the process of S. aureus infection. In this report, we found that bavachin, a natural flavonoid, not only efficiently inhibited the hemolytic activity of hla, but was also capable of inhibiting it on transcriptional and translational levels. Moreover, further data revealed that bavachin had no neutralizing activity on hla, which did not affect the formation of hla heptamers and exhibited no effects on the hla thermal stability. In vitro assays showed that bavachin was able to reduce the S. aureus-induced damage of A549 cells. Thus, bavachin repressed the lethality of pneumonia infection, lung bacterial load and lung tissue inflammation in mice, providing potent protection to mice models in vivo. Our results indicated that bavachin has the potential for development as a candidate hla inhibitor against S. aureus.

Advances in Fast Vessel-Wall Magnetic Resonance Imaging Using High-Density Coil Arrays

  • Yin, Xuetong;Li, Nan;Jia, Sen;Zhang, Xiaoliang;Li, Ye
    • Investigative Magnetic Resonance Imaging
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    • v.25 no.4
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    • pp.229-251
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    • 2021
  • Arteriosclerosis is the leading cause of stroke, with a fatality rate surpassing that of ischemic heart disease. High-resolution vessel wall magnetic resonance imaging is generally recognized as a non-invasive and panoramic method for the evaluation of arterial plaque; however, this method requires improved signal-to-noise ratio and scanning speed. Recent advances in high-density head and neck coil arrays are characterized by broad coverage, multiple channels, and closefitting designs. This review analyzes fast magnetic resonance imaging from the perspective of accelerated algorithms for vessel wall imaging and demonstrates the need for effective algorithms for signal acquisition using advanced radiofrequency system. We summarize different phased-array structures under various experimental objectives and equipment conditions, introduce current research results, and propose prospective research studies in the future.

Prevalence and Genotype Distribution of Human Papillomavirus Infections in Women Attending Hospitals in Chaozhou of Guangdong Province

  • Chen, Qiang;Luo, Zhao-Yun;Lin, Min;Lin, Qi-Li;Chen, Chan-Yu;Yang, Chun;Xie, Long-Xu;Li, Hui;Zheng, Jia-Kun;Yang, Li-Ye;Ju, Gui-Zhi
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1519-1524
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    • 2012
  • Background: Human papillomavirus (HPV) infection is the main cause of cervical cancer. Limited epidemiologic data of HPV prevalence are available for women attending hospitals in southern China. This study aimed to evaluate the profiles of HPV infection and cytology status in gynecological outpatients in Chaozhou City. Methods: A total of 2833 eligible women were enrolled. The HPV GenoArray test was used for HPV detection and genotyping. Nearly one half of the HPV positive women received liquid-based cytology test. Logistic regression analysis was performed to assess the predictable effects of age and genotype for categories of abnormal cytology. Results: The prevalence of overall, high-risk, and low-risk HPV infection were 24.5%, 19.5% and 8.4%, respectively. A U-shaped age-specific prevalence curve was observed in overall HPV and high-risk HPV, but not in low-risk HPV, which declined with age increasing. The 6 most common high-risk HPV type in descending order, were types 52, 16, 58, 18, 68, and 33. Age and HPV genotype were both important determinants of abnormal cytology incidence, the older women (>45 years) and those infected with HPV type 16 and/or 18 having the highest risk for abnormal cytology. Conclusion: Our findings support the hypothesis that second-generation HPV prophylactic vaccines including HPV-52 and -58 may offer higher protection for women residing in Chaozhou and neighboring cities in Guangdong.

Expression and Effects of JMJD2A Histone Demethylase in Endometrial Carcinoma

  • Wang, Hong-Li;Liu, Mei-Mei;Ma, Xin;Fang, Lei;Zhang, Zong-Feng;Song, Tie-Fang;Gao, Jia-Yin;Kuang, Ye;Jiang, Jing;Li, Lin;Wang, Yang-Yang;Li, Pei-Ling
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3051-3056
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    • 2014
  • Previous studies have demonstrated that JMJD2A is a potential oncogene and is overexpressed in human tumors. However, its role in the endometrial carcinoma remains largely unknown. In this study, we discovered that JMJD2A was overexpressed in endometrial carcinoma, using immunohistochemistry, quantitative realtime polymerase chain reaction, and western blotting. Downregulation of JMJD2A led to reduced endometrial carcinoma RL95-2 and ISK cell proliferation, invasion and metastasis as asessed with cell counting kit-8, cell migration and invasive assays. Collectively, our results support that JMJD2A is a promoter of endometrial carcinoma cell proliferation and survival, and is a potential novel drug target.

A Full Rate Dual Relay Cooperative Approach for Wireless Systems

  • Hassan, Syed Ali;Li, Geoffrey Ye;Wang, Peter Shu Shaw;Green, Marilynn Wylie
    • Journal of Communications and Networks
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    • v.12 no.5
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    • pp.442-448
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    • 2010
  • Cooperative relaying methods have attracted a lot of interest in the past few years. A conventional cooperative relaying scheme has a source, a destination, and a single relay. This cooperative scheme can support one symbol transmission per time slot, and is caned full rate transmission. However, existing fun rate cooperative relay approaches provide asymmetrical gain for different transmitted symbols. In this paper, we propose a cooperative relaying scheme that is assisted with dual relays and provides full transmission rate with the same macro-diversity to each symbol. We also address equalization for the dual relay transmission system in addition to addressing the issues concerning the improvement of system performance in terms of optimal power allocations.