Commercially-important species of fish and a crustacean from four sites in the Musa estuary and a site in the Persian Gulf have been analysed for the presence and location of microplastics (MPs). A total of 828 MPs were detected in the guts (gastrointestinal tracts), skin, muscle, gills and liver of demersal and pelagic fish (Platycephalus indicus, Saurida tumbil, Sillago sihama, Cynoglossus abbreviatus) from all five sites and in the exoskeleton and muscle of the tiger prawn, Penaeus semisulcatus, from three sites. On an individual basis, MPs were most abundant in P. indicus (mean = 21.8) and least frequently encountered in P. semisulcatus (mean = 7.8), but when normalized on a mass basis, MPs ranged from 0.16 g for C. abbreviatus to 1.5 g for P. semisulcatus. Microscopic analyses (polarized light, fluorescence, SEM/EDS) revealed that MPs were mainly fibrous fragments (with a few angular fragments) of various colour and size (<100 μm to > 1000 μm) and with strong C and O signatures. Additional particles detected that were distinctly different in colour, morphology, brittleness and elemental composition (part-metallic, and containing Cu) were suspected of being fragments of antifouling paint. The means of entry of MPs into tissues not involved in digestion are unclear but could be related to translocation or adherence. Regardless of the mode of accumulation, the presence of MPs in heavily fished species of fish and crustacean raises concerns about the potential transfer of synthetic materials into humans.

No abstract

No abstract

No abstract

The kinetic parameters of adenosine deaminase such as Km and Ki were determined in the absence and presence of adenine derivatives (R1-R24) in sodium phosphate buffer (50 mM; pH 7.5) solution at 27 degrees C. These kinetic parameters were used for QSAR analysis. As such, we found some theoretical descriptors to which the binding affinity of adenosine deaminase (ADA) towards several adenine nucleosides as inhibitors is correlated. QSAR analysis has revealed that binding affinity of the adenine nucleosides upon interaction with ADA depends on the molecular volume, dipole moment of the molecule, electric charge around the N1 atom, and the highest of positive charge for the related molecules.