In the present work we develop a novel approach for quantification of the energetics of C60 fullerene aggregation in aqueous media in terms of equilibrium aggregation constant KF. In particular, it is shown that the experimental determination of the magnitude of KF is possible only within the framework of the ‘up-scaled aggregation model’, considering the C60 fullerene water solution as a solution of fullerene clusters. Using dynamic light scattering (DLS) data we report the value, KF = 56 000 M−1, which is in good agreement with existing theoretical estimates and the results of energetic analyses. It is suggested that the proposed ‘up-scaled model’ may be used in any instances of non-specific aggregation resulting in formation of large spherical particles. The measurement of the translational diffusion coefficient and the dimensions of the light scattering particles using a DLS approach with respect to C60 fullerene aggregates is found to contain significant systematic errors originating from the interaction effect that is well-known for micellar solutions. As a result, corrections to the equations associated with DLS data are proposed.
20 July 2017 in Beilstein Journal of Nanotechnology
The self-organization of C60 fullerene and cisplatin in aqueous solution was investigated using the computer simulation, dynamic light scattering and atomic force microscopy techniques. The results evidence the complexation between the two compounds. The genotoxicity of С60 fullerene, Cis and their complex was evaluated in vitro with the comet assay using human resting lymphocytes and lymphocytes after blast transformation. The cytotoxicity of the mentioned compounds was estimated by Annexin V/PI double staining followed by flow cytometry. The results clearly demonstrate that water-soluble C60 fullerene nanoparticles (0.1 mg/mL) do not induce DNA strand breaks in normal and transformed cells. C60 fullerene in the mixture with Cis does not influence genotoxic Cis activity in vitro, affects the cell-death mode in treated resting human lymphocytes and reduces the fraction of necrotic cells.
The Tetrastichinae fauna of the Middle Volga Region comprises 115 species of 16 genera. Quadrastichus rosarum sp. n. is described as an endoparasitoid of Torymus bedequaris L. (Hymenoptera, Torymidae); the latter develops in galls of Dasineura rosarum (Hardy) (Diptera, Cecidomyiidae) on Rosa canina L. Aprostocetus populi (Kurdjumov) is redescribed and transferred from Tetrastichus to Aprostocetus. Thirty-three species are recorded for the Middle Volga Region for the first time. The genus Puklina Graham is new to the Russian fauna. New hosts are reported for five species of Tetrastichinae.
1 October 2011 in The Journal of Chemical Thermodynamics