The electronic structures of carbon nanotube/RuO2 core/shell nanocomposite (RuO2 thin layer coated multiwalled carbon nanotubes (MWNTs)) have been studied by X-ray absorption near-edge structures (XANES) at C K-edge, O K-edge, and Ru M5,4- and L3-edges. The variation in white-line features of the XANES at these edges supports strongly that RuO2 interacts with MWNTs through Ru−O−C bonding, which also results in charge redistribution between C 2p-derived states in MWNT and the conduction band in RuO2. Such chemical bonding is necessary to immobilize RuO2 on MWNT and ensures good conductivity of MWNT/RuO2 core/shell nanocomposite.

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Six steroid derivatives, 1-6, and five butyrolactone derivatives, 7-11, were isolated from the fermentation broth of a gorgonian-derived Aspergillus sp. fungus. Their structures were elucidated on the basis of NMR and MS spectral data. Compound 1 is a new, highly conjugated steroid. The NMR and MS data of 7 and 8 are reported for the first time, as their structures were listed in SciFinder Scholar with no associated reference. Compounds 1, 4, 5, and 8-11 inhibited the larval settlement of barnacle Balanus amphitrite with EC50 values ranging from 0.63 to 18.4 μg ml(-1) . Butyrolactone derivatives 7 and 8 showed pronounced antibacterial activities against Staphylococcus aureus with the same MIC values as the positive control ciprofloxacin (MIC 1.56 μM for all three compounds).