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Shengnan Xie Li Li Baihe Zhan Xue Shen Xuming Deng Wenxi Tan Tianqi Fang 《Molecules (Basel, Switzerland)》2022,27(9)
The emergence of the plasmid-mediated colistin resistance gene mcr-1 has resulted in the loss of available treatments for certain severe infections. Here we identified a potential inhibitor of MCR-1 for the treatment of infections caused by MCR-1-positive drug-resistant bacteria, especially MCR-1-positive carbapenem-resistant Enterobacteriaceae (CRE). A checkerboard minimum inhibitory concentration (MIC) test, a killing curve test, a growth curve test, bacterial live/dead assays, scanning electron microscope (SEM) analysis, cytotoxicity tests, molecular dynamics simulation analysis, and animal studies were used to confirm the in vivo/in vitro synergistic effects of pogostone and colistin. The results showed that pogostone could restore the bactericidal activity of colistin against all tested MCR-1-positive bacterial strains or MCR-1 mutant–positive bacterial strains (FIC < 0.5). Pogostone does not inhibit the expression of MCR-1. Rather, it inhibits the binding of MCR-1 to substrates by binding to amino acids in the active region of MCR-1, thus inhibiting the biological activity of MCR-1 and its mutants (such as MCR-3). An in vivo mouse systemic infection model, pogostone in combination with colistin resulted in 80.0% (the survival rates after monotherapy with colistin or pogostone alone were 33.3% and 40.0%) survival at 72 h after infection of MCR-1-positve Escherichia coli (E. coli) ZJ487 (blaNDM-1-carrying), and pogostone in combination with colistin led to one or more order of magnitude decreases in the bacterial burdens in the liver, spleen and kidney compared with pogostone or colistin alone. Our results confirm that pogostone is a potential inhibitor of MCR-1 for use in combination with polymyxin for the treatment of severe infections caused by MCR-1-positive Enterobacteriaceae. 相似文献
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本文简要讨论了码分多址移动通信中多址用户干扰的产生和抵消机理,并分别介绍了前向链路和反向链路的多址用户干扰抵消技术。 相似文献
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We study the H+CH4/CD4→H2/HD+CH3/CD3 reactions using the time sliced velocity map ion imaging technique. Ion images of the CH3/CD3 products were measured by the (2+1) resonance enhanced multi-photon ionization (REMPI) detection method. Besides the CH3/CD3 products in the ground state, ion images of the vibrationally excited CH3/CD3 products were also observed at two collision energies of 0.72 and 1.06 eV. It is shown that the angular distribution of the products CH3/CD3 in vibrationally excited states gradually vary from backward scattering to sideways scattering as the collision energy increases. Compared to the CH3/CD3 products in the ground state, the CH3/CD3 products in vibrationally excited states tend to be more sideways scattered, indicating that larger impact parameters play a more important role in the vibrationally excited product channels. 相似文献
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Aperiodic molybdenum/silicon (Mo/Si) multilayer designed as a broadband reflective mirror with mean reflectivity of 10% over a wide wavelength range of 12.5-28.5 nm at incidence angle of 5° is developed using a numerical optimized method. The multilayer is prepared using direct current magnetron sputtering technology. The reflectivity is measured using synchrotron radiation. The measured mean reflectivity is 7.0% in the design wavelength range of 12.5-28.5 nm. This multilayer broadband reflective mirror can be used in extreme ultraviolet measurements and will greatly simplify the experimental arrangements. 相似文献
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论文概述了费索干涉仪型激光波长计的原理和标定。详细分析了环境温度变化使仪器参数发生微小变化;论述了SIOM-01激光波长计以一种新颖的将标准激光引入测量光路的方法,随时对仪器参数实行单点标定,克服了由环境温度变化引进的测量误差。 相似文献
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合成孔径声呐成象的难点之一在于孔径上载体的运动不稳定性影响了合成孔径上水听器接收的信号的相干性,其结果将导致图像的畸变和分辨率的降低。首先讨论了运动误差对合成孔径声呐(SAS)成像的影响及运动补偿的必要性。在分析位移相位中心运动补偿法的基础上,提出了一种改进算法。该方法首先估计时延,然后再对剩余误差进行相位估计,从而扩大了算法适用的运动误差范围。文中给出了利用该方法的计算机仿真结果和部分水池实验结果,从结果可以看出,该方法有效地修正了在合成孔径上由于介质和载体不稳定带来的不相干性,提高了成像的质量。 相似文献