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Here, a novel N,B-doped graphene aerogel, abbreviated as N,B-GA, was obtained via a two-step approach and served as a metal-free catalyst for the oxygen reduction reaction (ORR). This two-step method involved a hydrothermal reaction and a pyrolysis procedure, guaranteeing the efficient insertion of the heteroatoms. The resulting three-dimensional (3D) N,B-GA obtained at pyrolysis temperature of 1000 °C exhibited outstanding catalytic activity for the oxygen reduction reaction (ORR), comparable to that of Pt/C. In addition, the catalytic activity of this 3D N,B-GA was obviously better than that of the nitrogen-doped graphene aerogel (N-GA) and boron-doped graphene aerogel (B-GA) in terms of the onset potential, half-wave potential and diffusion limiting current density. The superior catalytic reactivity arises from the synergistic coupling of the B and N dopants within the graphene domains.

Minocycline is a broad-spectrum tetracycline antibiotic. A number of preclinical studies have shown that minocycline exhibits neuroprotective effects in various animal models of neurological diseases. However, it remained unknown whether minocycline is effective to prevent neuron loss. To systematically evaluate its effects, minocycline was used to treat Dicer conditional knockout (cKO) mice which display age-related neuron loss. The drug was given to mutant mice prior to the occurrence of neuroinflammation and neurodegeneration, and the treatment had lasted 2 months. Levels of inflammation markers, including glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule1 (Iba1) and interleukin6 (IL6), were significantly reduced in minocycline-treated Dicer cKO mice. In contrast, levels of neuronal markers and the total number of apoptotic cells in Dicer cKO mice were not affected by the drug. In summary, inhibition of neuroinflammation by minocycline is insufficient to prevent neuron loss and apoptosis.

Highly conductive silver-coated glass fiber (GF) was fabricated in an efficient and environment-friendly way. When the GF powder was immersed in dopamine solution, an adherent self-polymerized poly(dopamine) (PDA) layer was formed on the GF surface. PDA acts as both a linker between GF and silver nanoparticles and a reducing agent for reducing silver ions to metallic silver. The silver nanoparticles can be chemically bound to the catechol and amine functional groups in PDA by electroless plating using glucose as reducing agent. Chemical and physical characterizations of the silver-coated GF were carried out by using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Four-point probe was used to study the electrical resistivity of the silver-coated glass fibers. The results indicated that the silver coated on the GF surface was compact, uniform, continuous, and in a metallic crystal state. The silver content could be well controlled from 9.5 to 24 wt% by adjusting the reduction conditions. The electrical resistivity of the silver-coated glass fibers could be as low as 1.0 m • cm.

Thermal release of zeolite is conducive in hemostasis, but losing control will cause serious burns. How to balance the advantages and disadvantages is a challenge. Herein, a zeolite/cross-linked graphene sponge (Z-CGS) was design to break through this challenge. The CGS managed the heat release of zeolite by thermal conduction of graphene. Infrared thermal imager demonstrated the mild exothermic process and good thermal conductivity of the optimized Z-CGS. It controlled wound temperature below 42 °C effectively, as compared to 70 °C of naked zeolite. Blood clotting index further confirmed the contribution of thermal stimulation in Z-CGS. On the synergy of thermal and charge stimulations of zeolite, as well as physical adsorption of CGS, Z-CGS achieved outstanding hemostatic performance. Bleeding was stopped within 69 s in rat artery injury model, faster than that of the Quikclot Combat Gauze. Additionally, cytotoxicity assay and pathological analysis highlighted its biocompatibility. Z-CGS, therefore, was an outstanding composite of combining advantages of zeolite and graphene, while getting rid of the shortcomings of the basic unit. The thermal conductibility of graphene renews an avenue for the safe and highly efficient use of zeolite in hemostasis.

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