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Oxygen containing functional groups were introduced onto the surface of carbon nanotubes (CNTs) by oxidation with ammonium persulphate and nitric acid respectively. The capacities of oxidised CNTs to absorb Cr(VI) from simulating drinking water at 25°C were found to be influenced by surface chemistry and pore structure. The characteristic (002) X-ray diffraction peaks of oxidised CNTs were intensified relative to the unmodified CNTs, and their crystallite sizes were increased. The distribution range of the pore size of oxidised CNTs became narrower. The amounts of oxygen containing functional groups, such as carboxylic, phenolic and lactonic groups, were greatly enhanced by oxidation. The point of zero charge was greatly decreased from 5·08 of the original CNTs to 3·35 and 3·30 for the CNTs oxidised with (NH4)2S2O8 and HNO3 respectively. The results showed that the saturation adsorption of Cr(VI) on the oxidised CNTs was increased due to the oxygen containing functional groups despite the fact that the surface areas and pore volumes were decreased, especially on the HNO3 oxidised CNTs. [ABSTRACT FROM AUTHOR]

Chinese chestnut trees ( Castanea mollissima BL.) planted in a suburb of Beijing, China developed symptoms including yellowing, leaf crinkling, little leaf, shortened internodes, and empty burrs. Transmission electron microscopy revealed presence of phytoplasma cells in phloem sieve elements of the symptomatic chestnut trees. Molecular cloning and sequence analysis of PCR-amplified near-full length 16S rRNA gene indicated that the phytoplasma associated with the Chinese chestnut yellow crinkle disease is closely related to Japanese chestnut witches'-broom phytoplasma. This is the first report of a phytoplasmal disease in Chinese chestnut trees. [ABSTRACT FROM AUTHOR]

This study determined the tuf gene sequence of the phytoplasma specific to paulownia witches’-broom from Nanyang, China (hereby designated PaWB-Ny). The PaWB-Ny tuf gene was 1185 nucleotides in length and confirmed that the phytoplasma belongs to subgroup 16SrI-D of aster yellows. Three characteristic GTP-binding protein motifs were identified based on the peptide deduced from the tuf gene sequence. Results suggested that the elongation factor EF-Tu was localized in the cytoplasm and lacked hydrophobic transmembrane domains. Antibodies against PaWB-Ny EF-Tu were prepared by rabbit immunization with glutathione-S-transferase (GST)-tagged EF-Tu fusion protein expressed in Escherichia coli. EF-Tu exhibited a molecular weight of ∼43 kDa and was detected in PaWB-infected paulownia plants by western blot analysis. Indirect enzyme-linked immunosorbent assays (ELISA) and dot blotting analyses were performed with freezing and thawing treatments during antigen preparation. Dilution of extracts to an appropriate scale significantly reduced non-specific reactions. The resultant PaWB EF-Tu antibody reacted with antigens from plants infected with periwinkle virescence and chinaberry tree witches’-broom phytoplasmas, but not those infected with jujube witches’-broom or bishopwood witches’-broom phytoplasma. The EF-Tu was characteristically localized within the phytoplasmal cytoplasm of infected plant phloem tissues. [ABSTRACT FROM AUTHOR]