13 research outputs found

    Liquid–Liquid Equilibria of Benzene + <i>n</i>‑Heptane + <i>N</i>,<i>N</i>‑Dimethylformamide and Benzene + <i>n</i>‑Heptane + <i>N</i>,<i>N</i>‑Dimethylformamide + Ammonium Thiocyanate

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    The liquid–liquid equilibrium data for the systems including benzene + <i>n</i>-heptane + <i>N</i>,<i>N</i>-dimethylformamide (DMF) and benzene + <i>n</i>-heptane + DMF + ammonium thiocyanate were measured experimentally at 298.15 K or 303.15 K and atmospheric pressure. The selectivity coefficients of the complex solvent (DMF + NH<sub>4</sub>SCN) are generally higher than those of DMF, derived from the tie-line data. For the high selectivity that is from 15.03 to 69.90 at 298.15 K or from 15.04 to 61.02 at 303.15 K, the complex solvent, DMF + NH<sub>4</sub>SCN, could be used as an extracting agent to separate benzene from <i>n</i>-heptane

    Dual Electric/Magnetic Field-Modulated Nematic Liquid Crystal Smart Window Based on the Supramolecular Doping Effect of Halloysite Nanotube Directors

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    Nowadays in the environmentally friendly society, smart windows have been viewed as one of the attractive energy-saving technologies for green buildings. However, some inherent defects on anisotropy and compatibility still greatly limit their practical applications. Thus, we first utilized hollow heterocharged halloysite (HAL) nanotubes as the doping agent to build up a 4-cyano-4′-pentylbiphenyl (5CB)-based supramolecular liquid crystal (LC) composite with excellent electro-optical properties. In particular, the chemical modification of 5CB blocks on the surface of HAL nanotubes (5CB-HAL) greatly improved HAL’s compatibility with the host 5CB. In the applied alternating current (AC) electric field with a low frequency (60 Hz), the vertically aligned 5CB-HAL-doped LC composites with a low doping concentration of 1.0 wt % exhibited outstanding electrochromic performances, including high contrast (82%), a rapid response of about 200 ms, low driving threshold (0.157 V/μm), a wide viewing angle (120°), and a smooth running of at least 10,000 cycles. In particular, in situ grown superparamagnetic iron (II, III) oxide nanoparticles above the HAL nanotube surface further endowed this LC system with fresh magnetic modulation and better light tuning. It is anticipated to provide a cheap, facile, reliable, and promising technology for high-performance bimodal smart windows

    Dual Electric/Magnetic Field-Modulated Nematic Liquid Crystal Smart Window Based on the Supramolecular Doping Effect of Halloysite Nanotube Directors

    No full text
    Nowadays in the environmentally friendly society, smart windows have been viewed as one of the attractive energy-saving technologies for green buildings. However, some inherent defects on anisotropy and compatibility still greatly limit their practical applications. Thus, we first utilized hollow heterocharged halloysite (HAL) nanotubes as the doping agent to build up a 4-cyano-4′-pentylbiphenyl (5CB)-based supramolecular liquid crystal (LC) composite with excellent electro-optical properties. In particular, the chemical modification of 5CB blocks on the surface of HAL nanotubes (5CB-HAL) greatly improved HAL’s compatibility with the host 5CB. In the applied alternating current (AC) electric field with a low frequency (60 Hz), the vertically aligned 5CB-HAL-doped LC composites with a low doping concentration of 1.0 wt % exhibited outstanding electrochromic performances, including high contrast (82%), a rapid response of about 200 ms, low driving threshold (0.157 V/μm), a wide viewing angle (120°), and a smooth running of at least 10,000 cycles. In particular, in situ grown superparamagnetic iron (II, III) oxide nanoparticles above the HAL nanotube surface further endowed this LC system with fresh magnetic modulation and better light tuning. It is anticipated to provide a cheap, facile, reliable, and promising technology for high-performance bimodal smart windows

    Dual Electric/Magnetic Field-Modulated Nematic Liquid Crystal Smart Window Based on the Supramolecular Doping Effect of Halloysite Nanotube Directors

    No full text
    Nowadays in the environmentally friendly society, smart windows have been viewed as one of the attractive energy-saving technologies for green buildings. However, some inherent defects on anisotropy and compatibility still greatly limit their practical applications. Thus, we first utilized hollow heterocharged halloysite (HAL) nanotubes as the doping agent to build up a 4-cyano-4′-pentylbiphenyl (5CB)-based supramolecular liquid crystal (LC) composite with excellent electro-optical properties. In particular, the chemical modification of 5CB blocks on the surface of HAL nanotubes (5CB-HAL) greatly improved HAL’s compatibility with the host 5CB. In the applied alternating current (AC) electric field with a low frequency (60 Hz), the vertically aligned 5CB-HAL-doped LC composites with a low doping concentration of 1.0 wt % exhibited outstanding electrochromic performances, including high contrast (82%), a rapid response of about 200 ms, low driving threshold (0.157 V/μm), a wide viewing angle (120°), and a smooth running of at least 10,000 cycles. In particular, in situ grown superparamagnetic iron (II, III) oxide nanoparticles above the HAL nanotube surface further endowed this LC system with fresh magnetic modulation and better light tuning. It is anticipated to provide a cheap, facile, reliable, and promising technology for high-performance bimodal smart windows

    Data_Sheet_1_A Novel mcr-1 Variant Carried by an IncI2-Type Plasmid Identified From a Multidrug Resistant Enterotoxigenic Escherichia coli.DOCX

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    <p>In this study, we discovered a novel mobilized colistin resistance (mcr-1) gene variant, named mcr-1.9, which was identified in a colistin-resistant enterotoxigenic Escherichia coli (ETEC) strain from a clinical diarrhea case. The mcr-1.9 gene differs from mcr-1 at position 1036 due to a single nucleotide polymorphism (G→A), which results in an aspartic acid residue being replaced by an asparagine residue (Asp346→Asn) in the MCR-1 protein sequence. Antimicrobial susceptibility testing showed that the mcr-1.9-harboring ETEC strain is resistant to colistin at a minimum inhibitory concentration of 4 μg/ml. Plasmid profiling and conjugation experiments also suggest that the mcr-1.9 variant can be successfully transferred into the E. coli strain J53, indicating that the gene is located on a transferable plasmid. Bioinformatics analysis of data obtained from genome sequencing indicates that the mcr-1.9 gene is located on a 64,005 bp plasmid which has been named pEC26. This plasmid was found to have high similarity to the mcr-1-bearing IncI2-type plasmids pWF-5-19C (99% identity and 99% coverage) and pmcr1-IncI2 (99% identity and 98% coverage). The mcr-1.9-harboring ETEC also shows multidrug resistance to nine classes of antibiotics, and contains several virulence and antimicrobial-resistance genes suggested by the genome sequence analysis. Our report is the first to identify a new mcr-1 variant in an ETEC isolated from a human fecal sample, raising concerns about the existence of more such variants in human intestinal flora. Therefore, we believe that an undertaking to identify new mcr-1 variants in the bacterial communities of human intestines is of utmost importance, and that measures need to be taken to control the spread of mcr-1 and its variants in human intestinal microflora.</p

    Dominant serotype distribution and antimicrobial resistance profile of <i>Shigella</i> spp. in Xinjiang, China

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    <div><p><i>Shigella</i> represents one of the major diarrhea-inducing pathogens threatening public health, but its prevalence and antimicrobial resistance profile in Xinjiang Uygur Autonomous region, China, remains unclear. We conducted comprehensive investigation of <i>Shigella</i> serotype distribution and antimicrobial resistance pattern in Xinjiang, identifying 458 <i>Shigella</i> isolates between 2008 to 2014. <i>Shigella flexneri</i> was identified as predominant species, and several <i>S</i>. <i>flexneri</i> serotypes were isolated, including atypical serotypes 1c, 2c, and 4s. Dominant <i>S</i>. <i>flexneri</i> serotypes were 2a, 1b, 2b, and Xv, different from those generally dominant in China. A hybrid serotype pattern was observed, which included the major Chinese serotypes (2a, Xv) and those predominant in Pakistan (1b, 2b). <i>Shigella sonnei</i> was shown to have a lower frequency compared with that generally observed in China, but an increasing trend of infections associated with this pathogen was observed. Furthermore, a high frequency of drug resistance and different <i>Shigella</i> antimicrobial resistance patterns were demonstrated as well, including very severe resistance phenotypes, such as multidrug resistance and resistance to frontline antibiotics. Seventy-five cephalosporin-resistant <i>Shigella</i> isolates were frequently identified with the resistance determinants that can undergo horizontal transfer, such as <i>bla</i><sub>OXA</sub>, <i>bla</i><sub>TEM</sub>, <i>bla</i><sub>CTX-M</sub>, and integrons, facilitating the development of cephalosporin resistance among <i>Shigella</i> subtypes. Additionally, genetic analyses demonstrated that all 86 quinolone-resistant <i>S</i>. <i>flexneri</i> isolates possess 3–4 mutation sites in quinolone resistance-determining regions, primarily contributing to their resistance to quinolone. However, <i>S</i>. <i>sonnei</i> isolates were not shown to be quinolone resistant. Co-resistance to cephalosporins and quinolones was detected in 17 <i>S</i>. <i>flexneri</i> isolates, and these isolates were additionally multidrug resistant and carried β-lactamase genes and quinolone-resistance determinants. As is demonstrated in this study, dominant serotypes of <i>Shigella</i> were distributed in unique trend with dangerous drug resistance patterns. Novel strategies are urgently required to prevent the development of drug resistance among diarrhea-inducing pathogens.</p></div

    Trends in <i>Shigella</i> prevalence in isolates collected in Xinjiang between 2008 and 2014.

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    <p>Variations in the frequencies of <i>S</i>. <i>flexneri</i> and <i>S</i>. <i>sonnei</i> with time are presented. In each column, frequencies of <i>S</i>. <i>flexneri</i> and <i>S</i>. <i>sonnei</i> are shown.</p
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