Adsorption of Pb and Zn from binary metal solutions and in the presence of dissolved organic carbon by DTPA-functionalised, silica-coated magnetic nanoparticles.

The ability of diethylenetriaminepentaacetic acid (DTPA)-functionalised, silica-coated magnetic nanoparticles to adsorb Pb and Zn from single and bi-metallic metal solutions and from solutions containing dissolved organic carbon was assessed. In all experiments 10 mL solutions containing 10 mg of nanoparticles were used. For single metal solutions (10 mg L-1 Pb or Zn) at pH 2 to 8, extraction efficiencies were typically >70%. In bi-metallic experiments, examining the effect of a background of either Zn or Pb (0.025 mmol L-1) on the adsorption of variable concentrations (0-0.045 mmol L-1) of the other metal (Pb or Zn, respectively) adsorption was well modelled by linear isotherms (R2 > 0.60; p ≤ 0.001) and Pb was preferentially adsorbed relative to Zn. In dissolved organic carbon experiments, the presence of fulvic acid (0, 2.1 and 21 mg DOC L-1) reduced Pb and Zn adsorption from 0.01, 0.1 and 1.0 mmol L-1 solutions. However, even at 21 mg DOC L-1 fulvic acid, extraction efficiencies from 0.01 to 0.1 mmol L-1 solutions remained >80% (Pb) and >50% (Zn). Decreases in extraction efficiency were significant between initial metal concentrations of 0.1 and 1.0 mmol L-1 indicating that at metal loadings between c. 100 mg kg-1 and 300 mg kg-1 occupancy of adsorption sites began to limit further adsorption. The nanoparticles have the potential to perform effectively as metal adsorbents in systems containing more than one metal and dissolved organic carbon at a range of pH values.

Novel monosaccharides as potent inhibitors of cell proliferation.

The effects of several novel monosaccharides upon thymidine incorporation into both normal and tumour cells were investigated. The monosaccharide 2-deoxy-3-[1-(R)-(ethoxycarbonyl)ethyl]- alpha-D-allo-pyranose had the most inhibitory effect on proliferation, with the (S)-enantiomer having less inhibitory effects. The chiral centre at carbon-7 was found to be an important part of the molecule, as 2-deoxy-3-[methoxycarbonyl methyl]-alpha-D-allo-pyranose had greatly decreased anti-proliferative properties in comparison with the parent compound. In addition, the 2-deoxy structure at carbon-2 was also found to be important, as 3-[1-(S)-(ethoxycarbonyl)ethyl]-alpha-D-allo-hexopyranose had greatly decreased inhibitory properties in comparison with the parent compound. The results indicate that these novel monosaccharides possess potent anti-proliferative properties, related to their chiral carbon-7 and 2-deoxy carbon-2 structure and suggest that further substitutions of the functional group at carbon-7 may improve these properties and possibly produce inhibitor selectivity for tumour cells in preference to normal cells.

A study of the oncogenicity of adenovirus type 2 transformed rat embryo cells.

Rat embryo cells were transformed by adenovirus type 2 at different multiplicities of infection. The oncogenic potential of the resulting transformed lines varied considerably but a relationship was found to exist between transforming virus dose and oncogenicity of the resulting transformed lines. Possible reasons for the considerable variation in oncogenicity of the transformed lines are discussed, giving particular consideration to cellular antigenicity and recent molecular biology studies of adenovirus type 2 transformed cell lines.