4 research outputs found

    Robust Antibacterial Activity of Xanthan-Gum-Stabilized and Patterned CeO2–x–TiO2 Antifog Films

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    Increased occurrence of antimicrobial resistance leads to a huge burden on patients, the healthcare system, and society worldwide. Developing antimicrobial materials through doping rare-earth elements is a new strategy to overcome this challenge. To this end, we design antibacterial films containing CeO; 2-; x; -TiO; 2; , xanthan gum, poly(acrylic acid), and hyaluronic acid. CeO; 2-; x; -TiO; 2; inks are additionally integrated into a hexagonal grid for prominent transparency. Such design yields not only an antibacterial efficacy of ∼100% toward; Staphylococcus aureus; and; Escherichia coli; but also excellent antifog performance for 72 h in a 100% humidity atmosphere. Moreover, FluidFM is employed to understand the interaction in-depth between bacteria and materials. We further reveal that reactive oxygen species (ROS) are crucial for the bactericidal activity of; E. coli; through fluorescent spectroscopic analysis and SEM imaging. We meanwhile confirm that Ce; 3+; ions are involved in the stripping phosphate groups, damaging the cell membrane of; S. aureus; . Therefore, the hexagonal mesh and xanthan-gum cross-linking chains act as a reservoir for ROS and Ce; 3+; ions, realizing a long-lasting antibacterial function. We hence develop an antibacterial and antifog dual-functional material that has the potential for a broad application in display devices, medical devices, food packaging, and wearable electronics

    East Asian monsoon variability over the last seven glacial cycles recorded by a loess sequence from the northwestern Chinese Loess Plateau

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    A 180-m-thick loess-paleosol sequence from the northwestern Chinese Loess Plateau was investigated to construct a high-resolution record of the East Asian monsoon variability over the last seven glacial-interglacial cycles. The low-field magnetic susceptibility (?, mass-specific) and the mean grain size are used as proxies for changes in the intensity of the East Asian summer and winter monsoon, respectively. Because of the weaker pedogenesis at the northwestern Chinese Loess Plateau compared to the central Chinese Loess Plateau, our ? and mean grain size records show a muted glacial-interglacial contrast for the Asian summer monsoon but an enhanced contrast for the Asian winter monsoon. Although better resolved, most orbital-scale East Asian monsoon variations captured by our ? and grain size records are similar to those reported from the central Chinese Loess Plateau. Nevertheless, variations in ? exhibit clear precessional cycles in three paleosol layers (i.e., S1, S2, and S3), corresponding with solar insolation maxima. Furthermore, unlike ? records at the central Chinese Loess Plateau where ? is dramatically enhanced at paleosol S5SS1 (corresponding to marine isotope stage 13), our new ? record shows a major enhancement at paleosol S4 (corresponding to marine isotope stage 11), which indicates geographic differences in the timing of local monsoon precipitation in the two regions
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