Identification of microplastics in fish ponds and natural freshwater environments of the Carpathian basin, Europe.

In the past few years, there has been a significant development in freshwater microplastic research. Pollution has been detected in lakes and rivers of several continents, but the number of papers is still marginal compared to the ones investigating marine environments. In this study, we present the first detection of microplastics (MPs) in Central and Eastern European (CEE) surface waters and, globally, the first detection in fish ponds. Samples were taken from different types of fish ponds and natural water bodies along a novel concept down to a particle size of 100 µm, then, after sample preparation, MPs were characterized using an FTIR microscope. 92% of the water samples contained MPs ranging from 3.52 to 32.05 particles/m3. MPs were detected in 69% of the sediment samples ranging from 0.46 to 1.62 particles/kg. Dominant abundance of polypropylene (PP) and polyethylene was shown in water and PP and polystyrene in sediment samples. First results also indicate that fish ponds may act as a deposition area for MPs.

Synthesis and characterization of oligodeoxynucleotides containing formamidopyrimidine lesions and nonhydrolyzable analogues.

Oligodeoxynucleotides containing formamidopyrimidine lesions and C-nucleoside analogues at defined sites were prepared by solid-phase synthesis and in some cases enzymatic ligation. Formamidopyrimidine lesions were introduced as dinucleotides to prevent rearrangement to their pyranose isomers. Oligodeoxynucleotides containing single diastereomers of C-nucleoside analogues of Fapy.dA were introduced by using the respective phosphoramidites. The formamidopyrimidine lesions reduce the T(M) of dodecamers relative to their unmodified nucleotide counterparts when opposite the nucleotide proper base-pairing partner. However, duplexes containing Fapy.dG-dA mispairs melt significantly higher than those comprised of dG-dA. All duplexes containing Fapy.dA-dX or its C-nucleoside analogue melt lower than the respective complexes containing dA-dX. Studies of the alkaline lability of oligodeoxynucleotides containing formamidopyrimidine lesions indicate that Fapy.dA is readily identified as an alkali-labile lesion with use of piperidine (1.0 M, 90 degrees C, 20 min), but Fapy.dG is less easily identified in this manner.