15,759 research outputs found

    PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses

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    Citation: Xiao, C. C., Ma, W. J., Sun, N., Huang, L. H., Li, Y. L., Zeng, Z. Y., . . . Liao, M. (2016). PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses. Scientific Reports, 6, 13. doi:10.1038/srep19474Additional Authors: Zhang, X.;Ning, Z. Y.;Qi, W. B.;Liao, M.Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts

    Obvious enhancement of the total reaction cross sections for 27,28^{27,28}P with 28^{28}Si target and the possible relavent mechanisms

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    The reaction cross sections of 27,28^{27,28}P and the corresponding isotones on Si target were measured at intermediate energies. The measured reaction cross sections of the N=12 and 13 isotones show an abrupt increase at % Z=15. The experimental results for the isotones with Z14Z\leq 14 as well as % ^{28}P can be well described by the modified Glauber theory of the optical limit approach. The enhancement of the reaction cross section for 28^{28}P could be explained in the modified Glauber theory with an enlarged core. Theoretical analysis with the modified Glauber theory of the optical limit and few-body approaches underpredicted the experimental data of 27^{27}P. Our theoretical analysis shows that an enlarged core together with proton halo are probably the mechanism responsible for the enhancement of the cross sections for the reaction of 27^{27}P+28^{28}Si.Comment: 16 pages, 5 figures, to be published in Phys.Rev.

    Effect of the Thickness of Undoped GaN Interlayers Between Multiple Quantum Wells and the P-Doped Layer on the Performance of GaN Light-Emitting Diodes

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    InGaN based light-emitting diodes (LEDs) with undoped GaN interlayer of variant thicknesses grown by metal-organic chemical vapor deposition technique have been investigated. It was found that the thickness of undoped GaN interlayers affected LEDs\u27 performance greatly. The LED with 50 nm undoped GaN interlayer showed higher light output power and lower reverse-leakage current compared with the others at 20 mA. Based on electrical and optical characteristics analysis and numerical simulation, these improvements are mainly attributed to the improvement of the quality of depletion region by inserting an undoped GaN layer, as well as reduction of the Shockley-Read-Hall recombination in InGaN/GaN MQWs

    Reducing water use by alternate-furrow irrigation with livestock wastewater reduces antibiotic resistance gene abundance in the rhizosphere but not in the non-rhizosphere

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    One effective approach to treating large amounts of wastewater produced during livestock production is to use it to irrigate crops. However, antibiotic compounds and antibiotic resistance genes (ARGs) associated with livestock wastewater may enter the soil and plants. ARGs are spread readily among microbial populations by mobile genetic elements, and may pose threats to human health. Compared with conventional furrow irrigation (CFI), alternate-furrow irrigation (AFI) can reduce water use and still achieve high yields. These different irrigation methods may influence the fate of ARGs in soil however, few reports have studied the combined effects of AFI and irrigation with livestock wastewater upon the distribution of ARGs in soil. Here, swine wastewater was used to irrigate cultivated peppers, and compared to relatively ARG-free groundwater. AFI was compared to CFI (100%) at three AFI irrigation rates (80%, 65% and 50% of CFI). The results showed that wastewater irrigation resulted in greater accumulation of antibiotic compounds and ARGs in soil than groundwater. The effect of wastewater was much more pronounced in the rhizosphere than non-rhizosphere soil. Compared with CFI, AFI using wastewater reduced the relative abundance of ARGs in the pepper rhizosphere, but the concentration of antibiotic compounds was largely unaffected; though antibiotic compound concentrations in roots were significantly lower, the abundance of ARGs in roots at 50% and 65% rates and in fruits at 50% rate were significantly increased when using wastewater. The soil bacterial communities did not change significantly between the different irrigation rates. Different behaviours were observed between ARGs and antibiotic compounds at different irrigation rates. Antibiotic compound availability plays an important role in the diffusion of ARGs. In conclusion, AFI of livestock wastewater can reduce the relative abundance of ARGs in rhizosphere soil, but low irrigation amount should be employed carefully for the safe agricultural production

    Energy-momentum for Randall-Sundrum models

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    We investigate the conservation law of energy-momentum for Randall-Sundrum models by the general displacement transform. The energy-momentum current has a superpotential and are therefore identically conserved. It is shown that for Randall-Sundrum solution, the momentum vanishes and most of the bulk energy is localized near the Planck brane. The energy density is ϵ=ϵ0e3ky\epsilon = \epsilon_0 e^{-3k \mid y \mid}.Comment: 13 pages, no figures, v4: introduction and new conclusion added, v5: 11 pages, title changed and references added, accepted by Mod. Phys. Lett.

    In-orbit demonstration of X-ray pulsar navigation with the Insight-HXMT satellite

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    In this work, we report the in-orbit demonstration of X-ray pulsar navigation with Insight-Hard X-ray Modulation Telescope (Insight-HXMT), which was launched on Jun. 15th, 2017. The new pulsar navigation method 'Significance Enhancement of Pulse-profile with Orbit-dynamics' (SEPO) is adopted to determine the orbit with observations of only one pulsar. In this test, the Crab pulsar is chosen and observed by Insight-HXMT from Aug. 31th to Sept. 5th in 2017. Using the 5-day-long observation data, the orbit of Insight-HXMT is determined successfully with the three telescopes onboard - High Energy X-ray Telescope (HE), Medium Energy X-ray Telescope (ME) and Low Energy X-ray Telescope (LE) - respectively. Combining all the data, the position and velocity of the Insight-HXMT are pinpointed to within 10 km (3 sigma) and 10 m/s (3 sigma), respectively.Comment: Accepted by the Astrophysical Journal Supplemen
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