417 research outputs found

    Enterovirus 71 Suppresses miR-17-92 Cluster Through Up-Regulating Methylation of the miRNA Promoter

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    Enterovirus 71 (EV71), the etiological agent of hand-foot-and-mouth disease, has become an increasing public health challenge worldwide. Accumulating evidence suggests that mammalian microRNAs (miRNAs), a class of non-coding RNAs of 18 to 24 nucleotides (nt) with important regulatory roles in cellular processes, participate in host antiviral defense and studies have suggested roles of miRNAs in EV71 replication and pathogenesis. In the current study, we reported that the expression of hsa-miR-17∼92 cluster was significantly downregulated during EV71 infection. Overexpression of hsa-miR-17∼92 inhibited, while inhibition of endogenous hsa-miR-17∼92 facilitated EV71 replication. We identified two sequences located at nt 3024 to 3038 and nt 2838 to 2862 of the EV71 (strain FY0805) genome as potential targets for hsa-miR-17-5p and miR-19a/b, respectively, which were validated by luciferase reporter assays and Western blot. Meanwhile, we identified DNA methylation as a novel mechanism of hsa-miR-17∼92 regulatory roles. The methylation of the miR-17-92 promoter was significantly increased (50%) upon EV71 infection, which appeared to be caused by the increased expression of DNMT3B but not DNMT1 and DNMT3A. Furthermore, we demonstrated that the members of miR-17-92 cluster were decreased in the sera of EV71 infected patients, suggesting the clinical implication and the potential therapeutic application of miR-17-92

    What Factors Influence Chinese Students to Choose Master Program in JMC: A Phenomenological Study

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    The number of Chinese postgraduates in JMC has steadily increased with the growing number of JCC master’s programs in in China. Little is known about key factors that influence Chinese students’ decisions in choosing which program attend. In order to fill a gap in the academic field, a qualitative phenomenological approach was applied to examine the experiences of seven Chinese master’s students in JMC from three different universities in Zhejiang province, China. Three important themes have been created including (1) geographical advantages; (2) recommendation of peers and professors; and (3) course design and curriculum. These findings have important implications for school officials and decision makers, with respect to allocating their resources wiser to make masters programs in JMC more attractive. In addition, this research study is the first analysis of its kind to apply a phenomenological approach to study experiences of Chinese students in making decisions of choosing a master’s program. This study lays a valuable foundation for similar topics through a qualitative research method

    The Magellan M2FS spectroscopic survey of high-redshift galaxies: the brightest Lyman-break galaxies at z∼6z \sim 6

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    We present a study of a sample of 45 spectroscopically confirmed, UV luminous galaxies at z∼6z\sim 6. They were selected as bright Lyman-break galaxies (LBGs) using deep multi-band optical images in more than 2 deg2^2 of the sky, and subsequently identified via their strong Lyα\alpha emission. The majority of these LBGs span an absolute UV magnitude range from −22.0-22.0 to −20.5-20.5 mag with Lyα\alpha equivalent width (EW) between ∼\sim10 and ∼\sim200 \AA, representing the most luminous galaxies at z∼6z\sim 6 in terms of both UV continuum emission and Lyα\alpha line emission. We model the SEDs of 10 LBGs that have deep infrared observations from HST, JWST, and/or Spitzer, and find that they have a wide range of stellar masses and ages. They also have high star-formation rates ranging from a few tens to a few hundreds of Solar mass per year. Five of the LBGs have JWST or HST images and four of them show compact morphology in these images, including one that is roughly consistent with a point source, suggesting that UV luminous galaxies at this redshift are generally compact. The fraction of our photometrically selected LBGs with strong Lyα\alpha emission (EW>25\mathrm{EW}>25 \AA) is about 0.20.2, which is consistent with previous results and supports a moderate evolution of the IGM opacity at the end of cosmic reionization. Using deep X-ray images, we do not find evidence of strong AGN activity in these galaxies, but our constraint is loose and we are not able to rule out the possibility of any weak AGN activity.Comment: 19 pages, 11 figures, Accepted for publication in Ap

    Application of modern timber structure in short and medium span bridges in China

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    Abstract: A series of problems about Chinese bridges with short and medium span recent years were analyzed in this paper. The necessity and feasibility of modern timber structure applied in short and medium span bridges in China were also put forward. The results showed that the short and medium span bridges had many problems, such as monotonous structural forms, serious environmental pollution, multiple bridge defects and difficulty in maintenance. With the development of connection and maintenance technology of modern timber structure and its advantages of light self-weight, environmental coordination, high carrying capacity, excellent durability and abundant structural forms, it was necessary and feasible to apply modern timber structure in short and medium span bridges in China. More emphasis on the construction of modern timber structure should be conducted to expand its application scopes and improve the construction proportion of short and medium span timber bridges

    Actuator and Sensor Fault Classification for Wind Turbine Systems Based on Fast Fourier Transform and Uncorrelated Multi-Linear Principal Component Analysis Techniques

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    In response to the high demand of the operation reliability and predictive maintenance, health monitoring and fault diagnosis and classification have been paramount for complex industrial systems (e.g., wind turbine energy systems). In this study, data-driven fault diagnosis and fault classification strategies are addressed for wind turbine energy systems under various faulty scenarios. A novel algorithm is addressed by integrating fast Fourier transform and uncorrelated multi-linear principal component analysis techniques in order to achieve effective three-dimensional space visualization for fault diagnosis and classification under a variety of actuator and sensor faulty scenarios in 4.8 MW wind turbine benchmark systems. Moreover, comparison studies are implemented by using multi-linear principal component analysis with and without fast Fourier transform, and uncorrelated multi-linear principal component analysis with and without fast Fourier transformation data pre-processing, respectively. The effectiveness of the proposed algorithm is demonstrated and validated via the wind turbine benchmark

    Application of a model-driven simultaneous prestack inversion of rock physical properties in ultra-deep Ordovician carbonate reservoirs in the Shunbei area

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    Synchronous prestack inversion technology has been widely used to predict the fluid and lithological properties of reservoirs. Its prediction accuracy depends on the seismic data quality. Ultra-deep carbonate reservoirs in the Shunbei area of the Tarim Basin were used as research objects. Based on the shear wave (S-wave) prediction method, petrophysical logging analysis was carried out to select the physical property-sensitive elastic parameters. A physical property indicator with porosity as the target curve was constructed to quantitatively characterize the differences in physical properties in this area. The signal-to-noise ratio (SNR) and resolution of the dataset were improved by preprocessing the seismic and logging data. P- and S-wave impedances and densities obtained from prestack synchronous inversion, which integrate the physical property indicator model. Spatial distribution and transverse variation of the physical parameters of the Ordovician carbonate reservoirs are described. The planar distribution of reservoirs can be effectively predicted
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