Activity

Ion-conductive hydrogel sensors have attracted great research interests for applications in wearable devices, electronic skins, and implantable sensors, but most such sensors are fragile, with low conductivity and sensitivity. This study reports on novel ion-conductive double network hydrogels with a cross-linked helical structure, hydrophobic association, and metal-ion coordination. The helical κ-carrageenan first network and the second network cross-linked by Pluronic F127 diacrylate micelles and tridentate Fe3+-COO- coordination work synergistically to show the tensile strength of 2.7 MPa, fracture strain of 1400%, and tensile toughness of 9.82 MJ m-3 and fatigue resistance against cyclic loadings with high strains. The hydrogels show an ion conductivity of 1.15 S m-1, a strain sensitivity of up to 2.8, and a pressure sensitivity of 0.33 kPa-1. Sensor arrays fabricated from the conductive hydrogels provide an in-plane detection of pressures less than 200 Pa. Such hydrogel sensors have potential applications to electron skins and implantable sensors.There is limited evidence indicating that drug-eluting dressings are clinically more effective than simple conventional dressings. To shed light on this concern, we have performed evidence-based research to evaluate the antimicrobial action of thymol (THY)-loaded antimicrobial dressings having antibiofilm forming ability, able to eradicate intracellular and extracellular pathogenic bacteria. We have used four different Staphylococcus aureus strains, including the ATCC 25923 strain, the Newman strain (methicillin-sensitive strain, MSSA) expressing the coral green fluorescent protein from the vector pCN47, and two clinical reference strains, Newman-(MSSA) and USA300-(methicillin-resistant strain), as traceable models of pathogenic bacteria commonly infecting skin and soft tissues. Compared to non-loaded dressings, THY-loaded polycaprolactone-based electrospun dressings were also able to eliminate pathogenic bacteria in coculture models based on infected murine macrophages. In addition, by using confocal microscopy and the conventional microdilution plating method, we corroborated the successful ability of THY in preventing also biofilm formation. Herein, we demonstrated that the use of wound dressings loaded with the natural monoterpenoid phenol derivative THY are able to eliminate biofilm formation and intracellular methicillin-sensitive S aureus more efficiently than with their corresponding THY-free counterparts.An organocatalytic enantioselective epoxidation of 2,3-disubstituted naphthoquinones with tert-butyl hydroperoxide as an oxidant was developed using a guanidine-urea bifunctional catalyst lacking C2 symmetry, which was designed based upon the insights obtained from the DFT calculation model for our previous C2 symmetric catalyst. The present organocatalytic reaction provides access to a variety of optically active naphthoquinone epoxides bearing aryl and methyl substituents at C2 and C3 in high yields with high enantioselectivities (up to 973 er).Though being a promising anode material for sodium-ion batteries (SIBs), MoS2 with high theoretical capacity shows poor rate capability and rapid capacity decay, especially involving the conversion of MoS2 to Mo metal and Na2S. UNC5293 Here, we report all-in-one MoS2 nanosheets tailored by porous nitrogen-doped graphene (N-RGO) for the first time to achieve superior structural stability and high cycling reversibility of MoS2 in SIBs. The all-in-one MoS2 nanosheets possess desirable structural characteristics by admirably rolling up all good qualities into one, including vertical alignment, an ultrathin layer, vacancy defects, and expanded layer spacing. Thus, the all-in-one MoS2@N-RGO composite anode exhibits an improvement in the charge transport kinetics and availability of active materials in SIBs, resulting in outstanding cycling and rate performance. More importantly, the restricted growth of all-in-one MoS2 by the porous N-RGO via a strong coupling effect dramatically improves the cycling reversibility of conversion reaction. Consequently, the all-in-one MoS2@N-RGO composite anode demonstrates excellent reversible capacity, outstanding rate capability, and superior cycling stability. This study strongly suggests that the all-in-one MoS2@N-RGO has great potential for practical application in high-performance SIBs.Metal sulfides have attracted tremendous research interest for developing high-performance electrodes for potassium-ion batteries (PIBs) for their high theoretical capacities. Nevertheless, the practical application of metal sulfides in PIBs is still unaddressed due to their intrinsic shortcomings of low conductivity and severe volume changes during the potassiation/depotassiation process. Herein, robust Fe7S8/C hybrid nanocages reinforced by defect-rich MoS2 nanosheets (Fe7S8/C@d-MoS2) were designed, which possess abundant multichannel and active sites for potassium-ion transportation and storage. Kinetic analysis and theoretical calculation verify that the introduction of defect-rich MoS2 nanosheets dramatically promotes the potassium-ion diffusion coefficient. The ex-situ measurements revealed the potassium-ion storage mechanism in the Fe7S8/C@d-MoS2 composite. Benefitting from the tailored structural design, the Fe7S8/C@d-MoS2 hybrid nanocages show high reversible capacity, exceptional rate property, and superior cyclability.Daytime radiative cooling is a passive strategy to cool down a terrestrial object under direct sunlight without the need of electricity input. It functions by simultaneously reflecting solar irradiance and sending heat as infrared (IR) thermal radiation through the atmospheric transparent window into the cold outer space. In spite of extensive studies on daytime radiative cooling, most of previous works were conducted in dry regions mainly in North America. Here, we explore the feasibility of achieving efficient radiative cooling in humid subtropical areas such as Hong Kong, where abundant atmosphere water vapor exists. In this case, the atmospheric transparent window is almost closed since water is highly absorptive of IR radiation. We report a simple approach to achieve efficient daytime radiative cooling in Hong Kong. Our design comprises an expanded polytetrafluoroethylene (ePTFE) film and a Ag layer deposited on a transparent glass substrate. We show that the combination of highly diffusely reflective ePTFE and all-band reflective Ag results in a reflectivity of 98% in the solar spectrum, allowing for a temperature drop up to 2.