Carbon-based aerogels, composed of interconnected threedimensional (3D) networks, have attracted intensive attention because of their unique physical properties, such as low density, high electrical conductivity, porosity, and specific surface area. [1][2][3] As a result, carbon-based aerogels are promising materials used as catalyst supports, [4] artificial muscles, [5] electrodes for supercapacitors, [6] absorbents, [7] and gas sensors. [8] Especially, ultralight or flexible carbon-based aerogels have many potential applications. For example, ultralight nitrogen-doped graphene framework, used as an absorbent for organic liquids or the active electrode material, exhibits a high absorption capacity and specific capacitance; [9] stretchable conductors, fabricated by infiltrating flexible graphene foam with elastic polymers, show high stability of electronic conductivity even under high stretching and bending strain. [10] Traditionally, to fabricate carbon aerogels, resorcinolformaldehyde organic aerogels were pyrolyzed in an inert atmosphere to form a highly cross-linked carbon structure. [11,12] The carbon aerogels always have a high density (100-800 mg cm À3 ) [11,13] and tend to break under compression. Carbon nanotube (CNT) sponges, [7] graphene foam, [10] and CNT forests [14] have been prepared through chemical vapor deposition (CVD). Meanwhile, CNTs and graphene can be employed as building blocks and assembled into macroscopic 3D architectures. [15][16][17][18] However, the harmful and expensive precursors or complex equipments involved in these syntheses dramatically hamper the large-scale production of these carbon-based aerogels for industry application. Recently, we have developed a template-directed hydrothermal carbonization process for synthesis of carbonaceous nanofiber hydrogels/aerogels on macroscopic scale by using glucose as precursors. [19] However, the use of expensive nanowire templates in this synthesis pushes us to explore a facile, economic, and environmentally friendly method to produce carbon-based nanostructured aerogels.Nowadays, there is a trend to produce carbon-based materials from biomass materials, as they are very cheap, easy to obtain, and nontoxic to humans, etc. [20] Bacterial cellulose (BC), a typical biomass material, is composed of interconnected networks of cellulose nanofibers, [21,22] and can be produced in large amounts in a microbial fermentation process. [22] Recently, we reported a highly conductive and stretchable conductor, fabricated from BC, shows great electromechanical stability under stretching and bending strain. [23] Herein, we report a facile route to produce ultralight, flexible, and fire-resistant carbon nanofiber (CNF) aerogels in large scale from BC pellicles. When used as absorbents, the CNF aerogels can absorb a wide range of organic solvents and oils with excellent recyclability and selectivity. The absorption capacity can reach up to 310 times the weight of the pristine CNF aerogels. Besides, the electrical conductivity of the CNF aerogel is highly s...

A solution to the classic unsolved problem of olefin hydromethylation is presented. This highly chemoselective method can tolerate labile and reactive chemical functionalities and uses a simple set of reagents. An array of olefins, including mono-, di-, and trisubstituted olefins, are all smoothly hydromethylated. This mild protocol can be used to simplify the synthesis of a specific target or to directly “edit” complex natural products and other advanced materials. The method is also amenable to the simple installation of radioactive and stable labeled methyl groups.

Carbon aerogels with 3D networks of interconnected nanometer-sized particles exhibit fascinating physical properties and show great application potential. Efficient and sustainable methods are required to produce high-performance carbon aerogels on a large scale to boost their practical applications. An economical and sustainable method is now developed for the synthesis of ultrathin carbon nanofiber (CNF) aerogels from the wood-based nanofibrillated cellulose (NFC) aerogels via a catalytic pyrolysis process, which guarantees high carbon residual and well maintenance of the nanofibrous morphology during thermal decomposition of the NFC aerogels. The wood-derived CNF aerogels exhibit excellent electrical conductivity, a large surface area, and potential as a binder-free electrode material for supercapacitors. The results suggest great promise in developing new families of carbon aerogels based on the controlled pyrolysis of economical and sustainable nanostructured precursors.

Viral RNAs produced during viral infection are recognized by the cytoplasmic RNA helicases retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5). A central adapter protein downstream of RIG-I and MDA5 is the mitochondrial membrane protein virus-induced signaling adaptor (VISA), which mediates the induction of type I interferons (IFNs) through the activation of transcription factors such as nuclear factor-kappaB (NF-kB) and IFN-regulatory factor-3 (IRF3). Here we found that hepatitis B virus (HBV)-encoded X protein (HBx) acts as an inhibitor of virus-triggered IRF3 activation and IFN-b induction. Reporter and plaque assays indicate that HBx inhibits signaling by components upstream but not downstream of VISA. Immunoprecipitation experiments indicate that HBx interacts with VISA and disrupts the association of VISA with its upstream and downstream components. These findings suggest that HBx acts as a suppressor of virus-triggered induction of type I IFNs, which explains the observation that HBV causes transient and chronic infection in hepatocytes but fails to activate the pattern recognition receptor-mediated IFN induction pathways.