Facile synthesis and wide-band electromagnetic wave absorption properties of carbon-coated ZnO nanorods

<p>In this work, a facile and scalable acetylene decomposition method was employed to synthesize carbon-coated ZnO (ZnO@C) nanorods. The characterization of morphology and structure analysis demonstrate that ZnO nanorod was well coated by an amorphous carbon shell with a thickness of about 20 nm. Comparted with ZnO, ZnO@C exhibit significantly enhanced microwave absorption properties. The effective absorption bandwidth with RL values exceeding –10 dB can reach 5.3 GHz for ZnO@C with a matching thickness of 2.5 mm. The excellent microwave absorption arose from enhanced dielectric loss caused by interfacial polarization, dipole polarization and the formation of conductive network.</p

Molecular Modelling reveals the inhibition mechanism and structure–activity relationship of curcumin and its analogues to <i>Staphylococcal aureus</i> Sortase A

<p>Previous studies found that the activity of Sortase A, a bacterial surface protein from <i>Staphylococcus aureus</i>, was inhibited by curcumin and its analogues. To explore this inhibitory mechanism, Sortase A and its inhibitors in complex systems were studied by molecular docking, molecular modelling, binding energy decomposition calculation and steered molecular dynamics simulations. Energy decomposition analysis indicated that PRO-163, LEU-169, GLN-172, ILE-182 and ILE-199 are key residues in Sortase A-inhibitor complexes. Furthermore, interactions between the methoxyl group on the benzene ring in the conjugated molecule (curcumin, demethoxycurcumin, bisdemethoxycurcumin) and VAL-168, LEU-169 and GLN-172 induce the inhibitory activity based on the energy decomposition and distance analyses between the whole residues and inhibitors. However, because of its coiled structure, the non-conjugated molecule, tetrahydrocurcumin, with key residues in the binding sites of Sortase A, interacted weakly with SrtA, leading to the loss of inhibitory activity. Based on these results, the methoxyl group on the benzene ring in the conjugated molecule largely influenced the inhibitory activity of the Sortase A inhibitors.</p

Additional file 1: of The Preparation of Au@TiO2 Yolk–Shell Nanostructure and its Applications for Degradation and Detection of Methylene Blue

Supporting information. Figure S1. SEM images of CNCs. Figure S2. TEM images and the size distribution analysis of Au nanoparticles of (a1 and a2) Au-30@TiO2; (b1 and b2) Au-50@TiO2; (c1 and c2) Au-80@TiO2; (d1 and d2) Au-120@TiO2. Figure S3. TEM image of the Au-80@TiO2 after photocatalytic reaction. (DOC 11017 kb

Flexible and Ultrathin Graphene/Aramid Nanofiber Carbonizing Films with Nacre-like Structures for Heat-Conducting Electromagnetic Wave Shielding/Absorption

Electromagnetic interference (EMI) shielding and electromagnetic wave absorption (EWA) materials with good thermal management and flexibility properties are urgently needed to meet the more complex modern service environment, especially in the field of smart wearable electronics. How to balance the relation of electromagnetic performance, thermal management, flexibility, and thickness in material design is a crucial challenge. Herein, graphene nanosheets/aramid nanofiber (C-GNS/ANF) carbonizing films with nacre-like structures were fabricated via the blade-coating/carbonization procedure. The ingenious configuration from highly ordered alignment GNS interactively connected by a carbonized ANF network can effectively improve the thermal/electrical conductivity of a C-GNS/ANF film. Specifically, the ultrathin C-GNS/ANF film with a thickness of 17 μm shows excellent in-plane thermal conductivity (TC) of 79.26 W m–1 K–1 and superior EMI shielding up to 56.30 dB. Moreover, the obtained C-GNS/ANF film can be used as a lightweight microwave absorber, achieving excellent microwave absorption performance with a minimum reflection loss of −56.07 dB at a thickness of 1.5 mm and a maximum effective absorption bandwidth of 5.28 GHz at an addition of only 5 wt %. Furthermore, the C-GNS/ANF films demonstrate good flexibility, outstanding thermal stability, and flame retardant properties. Overall, this work indicates a prospective direction for the development of the next generation of electromagnetic wave absorption/shielding materials with high-performance heat conduction

Ultralow-Threshold and Lightweight Biodegradable Porous PLA/MWCNT with Segregated Conductive Networks for High-Performance Thermal Insulation and Electromagnetic Interference Shielding Applications

Lightweight, biodegradable, thermally insulating, and electrically conductive materials play a vital role in achieving the sustainable development of our society. The fabrication of such multifunctional materials is currently very challenging. Here, we report a general, facile, and eco-friendly way for the large-scale fabrication of ultralow-threshold and biodegradable porous polylactic acid (PLA)/multiwalled carbon nanotube (MWCNT) for high-performance thermal insulation and electromagnetic interference (EMI) shielding applications. Thanks to the unique structure of the microporous PLA matrix embedded by conductive 3D MWCNT networks, the lightweight porous PLA/MWCNT with a density of 0.045 g/cm³ possesses a percolation threshold of 0.00094 vol %, which, to our knowledge, is the minimum value reported so far. Furthermore, the material exhibits excellent thermal insulation performance with a thermal conductivity of 27.5 mW·m^–1·K^–1, which is much lower than the best value of common thermal insulation materials. Moreover, it also shows outstanding EMI shielding performance characterized by its high shielding effectiveness (SE) values and absorption-dominated shielding feature. More importantly, its specific EMI SE is as high as 1010 dB·cm³·g^–1, which is superior to those of other shielding materials reported so far. Thus, this novel multifunctional material and its general fabrication methodology provide a promising way to meet the growing demand for high-performance multifunctional materials in sustainable development

Size-Selective Catalytic Growth of Nearly 100% Pure Carbon Nanocoils with Copper Nanoparticles Produced by Atomic Layer Deposition

In this paper, Cu nanoparticles with narrow size distribution are synthesized by reduction of CuO films produced by atomic layer deposition (ALD), which are used as catalysts for the catalytic growth of carbon nanostructures. By properly adjusting the ALD cycle numbers, the size of produced Cu nanoparticles can be well controlled. Uniform carbon nanocoils with near 100% purity can be obtained by using 50–80 nm Cu nanoparticles, while thin straight fibers and thick straight fibers are produced by applying 5–35 and 100–200 nm Cu nanoparticles, respectively. The mechanism of the particle size-dependent growth of the carbon nanostructure was analyzed based on the experimental results and theoretical simulation. Our results can provide important information for the preparation of helical carbon nanostructures with high purity. Moreover, this work also demonstrates that ALD is a viable technique for synthesizing nanoparticles with highly controllable size and narrow size distribution suitable for studying particle size-dependent catalytic behavior and other applications

Isolated iliac cryptococcosis in an immunocompetent patient

<p>Isolated iliac cryptococcosis in an immunocompetent patient</p

¹⁸FDG-PET/CT scan and histological examination.

<p><b>(A)</b>¹⁸FDG-PET/CT indicated hypermetabolic lesions in the bilateral iliac crest, especially in the left iliac crest. <b>(B)</b> Histological examinations (HE stain, left panel; PAS stain, right panel) after left iliac biopsy revealed round yeast cells. HE, hematoxylin and eosin; PAS, periodic acid–Schiff; ¹⁸FDG-PET/CT, ¹⁸fluorodeoxyglucose positron emission tomography and computed tomography.</p

MICs of 80 nm Pd@Ag NSs against 44 cryptococcal isolates with different molecular types or from different sources compared to fluconazole and amphotericin B.

<p>MICs of 80 nm Pd@Ag NSs against 44 cryptococcal isolates with different molecular types or from different sources compared to fluconazole and amphotericin B.</p

Macrophage killing assay and murine inhalation model.

<p>Both macrophage <b>(A)</b> (<i>P</i> < 0.01) and animal <b>(B)</b> (<i>P</i> < 0.001) infection experiments displayed attenuated virulence of the clinical isolate compared with the hypervirulent strain H99.</p