The effect of capping agents on the toxicity of silver nanoparticles to Danio rerio embryos.

Addition of capping agents like surfactants and polymers during the synthesis of nanoparticles may affect the stability and toxicity of dispersions of nanoparticles. This study revealed the impact of anionic, cationic, and amphoteric surfactants and a cationic polymer on the physical and chemical properties, stability and behavior of silver nanomaterials, as well as on the toxicity of nanosized silver particles with respect to zebrafish embryos. Some of the stabilizers applied were shown to significantly affect embryos of Danio rerio. Colloidal dispersions of stabilized silver nanoparticles were demonstrated to induce a complex mechanism of toxicity with respect to embryos of D. rerio, which is mainly explained by the toxicity of the organic ligand, while other parameters are somewhat inferior. The newly generated data on the toxicity of nanoparticles and their stabilizers with respect to D. rerio embryos reveal the complexity of the toxicity mechanism of nanoparticles impacting living systems.

Changes in the contents of strontium, barium, and lead in scales of bream Abramis brama from the Mozhaisk Reservoir over a quarter century.

The heavy metal contents in the scales of bream (Abramis brama) from the Mozhaisk Reservoir collected in the second half of the 1980s were compared to the current values. The concentrations of three out of the seven elements studied in the bream scales have changed severalfold during the past quarter century: that of strontium has decreased, and those of barium and lead have increased. Short-term variations of heavy metal contents have proved to be smaller than the observed long-term differences. There is grounds to believe that these long-term differences adequately reflect the changes that have occurred in the water body.

Western Siberia rivers and the boundaries between chromosomal races of the common shrew (Sorex araneus L. Lipotyphla, Mammalia).

In Western Siberia, most boundaries between common shrew chromosomal races have been found to pass along the banks of rivers, mainly those flowing in the meridional direction. The races Serov and Novosibirsk co-inhabited the right bank of the Irtysh. The easternmost point of the Novosibirsk race has been found on the middle Yenisei River, while the race Tomsk in this area was only on the right (eastern) bank.

[Evaluation of genetic homeostasis in animals at different stages of ontogenesis in the environment].

Modern methods of genetic homeostasis assessment in animals are described in the present article. The single gel-electrophoresis test (Comet Assay), micronuclei test, chromosome aberration frequency, and sister chromatid exchanges are reviewed in detail. The questions of test-sensitivity of given methods and principles or their application for genetic homeostasis assessment in wild populations of animals are considered.

[Nanoparticles in the environment and their effect on hydrobionts].

This paper summarizes the data on the effect of engineered nanoparticles on aquatic organisms. The issues of penetration and accumulation of nanoparticles in the body of hydrobionts and their toxic effect, biotransformation, and migration along food chains are considered. It is demonstrated that the behavior of nanomaterials in the environment and their effect on living organisms have been studied insufficiently and require close attention, because their release into the environment will increase in the very near future.