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131.
Sabeel P. Valappil Derren Ready Ensanya A. Abou Neel David M. Pickup Wojciech Chrzanowski Luke A. O'Dell Robert J. Newport Mark E. Smith Michael Wilson Jonathan C. Knowles 《Advanced functional materials》2008,18(5):732-741
Novel quaternary gallium‐doped phosphate‐based glasses (1, 3, and 5 mol % Ga2O3) were synthesized using a conventional melt quenching technique. The bactericidal activities of the glasses were tested against both Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive (Staphylococcus aureus, methicillin‐resistant Staphylococcus aureus, and Clostridium difficile) bacteria. Results of the solubility and ion release studies showed that these glass systems are unique for controlled delivery of Ga3+. 71Ga NMR measurements showed that the gallium is mostly octahedrally coordinated by oxygen atoms, whilst FTIR spectroscopy provided evidence for the presence of a small proportion of tetrahedral gallium in the samples with the highest gallium content. FTIR and Raman spectra also afford an insight into the correlation between the structure and the observed dissolution behavior via an understanding of the atomic‐scale network bonding characteristics. The results confirmed that the net bactericidal effect was due to Ga3+, and a concentration as low as 1 mol % Ga2O3 was sufficient to mount a potent antibacterial effect. The dearth of new antibiotics in development makes Ga3+ a potentially promising new therapeutic agent for pathogenic bacteria including MRSA and C. difficile. 相似文献
132.
Zichun Wang Luke A. O'Dell Xin Zeng Can Liu Shufang Zhao Wenwen Zhang Marianne Gaborieau Yijiao Jiang Jun Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18229-18236
Commercial bioethanol can be readily converted into ethylene by a dehydration process using solid acids, such as Brønsted acidic H‐ZSM‐5 zeolites, and thus, it is an ideal candidate to replace petroleum and coal for the sustainable production of ethylene. Now, strong Lewis acidic extra‐framework three‐coordinate Al3+ species were introduced into H‐ZSM‐5 zeolites to improve their catalytic activity. Remarkably, Al3+ species working with Brønsted acid sites can accelerate ethanol dehydration at a much lower reaction temperature and shorten the unsteady‐state period within 1–2 h, compared to >9 h for those without Al3+ species, which can significantly enhance the ethanol dehydration efficiency and reduce the cost. The reaction mechanism, studied by solid‐state NMR, shows that strong Lewis acidic EFAl‐Al3+ species can collaborate with Brønsted acid sites and promote ethanol dehydration either directly or indirectly via an aromatics‐based cycle to produce ethylene. 相似文献
133.
MacDougall GJ Aczel AA Carlo JP Ito T Rodriguez J Russo PL Uemura YJ Wakimoto S Luke GM 《Physical review letters》2008,101(1):017001
We have performed zero-field muon-spin-relaxation measurements on single crystals of La(2-x)SrxCuO4 to search for spontaneous currents in the pseudogap state. By comparing measurements on materials across the phase diagram, we put strict upper limits on any possible time-reversal symmetry breaking fields that could be associated with the pseudogap. Comparison between experimental limits and the proposed circulating current states effectively eliminates the possibility that such states exist in this family of materials. 相似文献
134.
O'Dell LA Gunawidjaja PN Holland MA Mountjoy G Pickup DM Newport RJ Smith ME 《Solid state nuclear magnetic resonance》2008,33(1-2):16-24
The HfO2-SiO2 system is attracting interest as a possible new dielectric material in semiconductor devices. Knowledge of the location of hafnium within the silica network and the effect hafnium has on the structure will be central to the successful use of this material system in this application. Here, sol-gel techniques have been used to manufacture (HfO2)x(SiO2)1-x samples (x=0.1, 0.2 and 0.4, each heat treated at 250, 500 and 750 degrees C) and these have been characterised by magic angle spinning (MAS) NMR (1H, 13C, 17 O, 29Si), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. 29Si MAS NMR showed that increasing the hafnia content decreases the connectivity of the silicate network, i.e. increases the range of differently connected SiO4 (Qn) units with more having increased numbers of non-bridging oxygens (i.e. lower n). FTIR and 17 O MAS NMR showed unequivocally that the x=0.4 sample phase-separated at higher temperatures, while in the x=0.1 sample the hafnium was homogeneously mixed into the SiO2 phase without any phase separation. 相似文献
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139.
John Bamberg S.P. Glasby Luke Morgan Alice C. Niemeyer 《Journal of Pure and Applied Algebra》2019,223(12):5428-5429
We give a correction to Fig. 1 and supporting text published in the paper: ‘Maximal linear groups induced on the Frattini quotient of a p-group’, J. Pure Appl. Algebra 222 (10) (2018) 2931–2951. 相似文献
140.
Hoeben W. F. L. M. van Ooij P. P. Schram D. C. Huiskamp T. Pemen A. J. M. Lukeš P. 《Plasma Chemistry and Plasma Processing》2019,39(3):597-626
Plasma Chemistry and Plasma Processing - Plasma activated deionized water from a hot arc 150 W PAW synthesizer has been analyzed for nitrite, nitrate and peroxide densities. Observed nitrite and... 相似文献