We calculated the cross sections of photolysis of OH, LiO, NaO, KO, HCl, LiCl, NaCl, KCl, HF, LiF, NaF, and KF molecules using quantum chemistry methods. The maximal values for photolysis cross sections of alkali metal monoxides are on the order of 10−18 cm2. The lifetimes of photolysis for quiet Sun at 1 astronomical unit are estimated as 2.0 × 105, 28, 5, 14, 2.1 × 105, 225, 42, 52, 2 × 106, 35 400, 486, and 30 400 s for OH, LiO, NaO, KO, HCl, LiCl, NaCl, KCl, HF, LiF, NaF, and KF, respectively. We performed a comparison between values of photolysis lifetimes obtained in this work and in previous studies. Based on such a comparison, our estimations of photolysis lifetimes of OH, HCl, and HF have an accuracy of about a factor of 2. We determined typical kinetic energies of main peaks of photolysis-generated metal atoms. Impact-produced LiO, NaO, KO, NaCl, and KCl molecules are destroyed in the lunar and Hermean exospheres almost completely during the first ballistic flight, while other considered molecules are more stable against destruction by photolysis.

A complex approach based on the use of test organisms belonging to different systematic groups (plants, invertebrates and vertebrates), as well as the nucleolar biomarker and the micronucleus test on their cells, was applied to assess the toxicity, cytotoxicity and genotoxicity of two pharmaceutical substances (metamizole sodium and acetylsalicylic acid) applied at ic(50) concentrations for mammalian cells. The compound acetylsalicylic acid was evaluated at a concentration (1.6 x 10(3) mg l(-1)) that was non-toxic for bioassays based on fish (Carassius auratus gibelio) and hydra (Hydra attenuata) and acutely toxic for bioassays with ceriodaphnia (Ceriodaphnia affinis) and onion (Allium cepa). The metamizole sodium solution (6.25%) demonstrated acute toxicity for the whole set of test organisms. Both drugs, after their 30-360 min influence on the test organisms, first changed the nucleolar size in plant and animal cells (i.e. the transcriptional activity of ribosomal genes was affected most significantly). Moreover, the metamizole sodium solution caused nucleolar structural damage in 90% of hydra cells as early as after 30 min of exposure. The acetylsalicylic acid solution inhibited essentially the rate of cell division in the meristem of onion roots (the mitotic index decreased to 9.6 per thousand, as compared 51.7 per thousand for the control). The carp incubation and the onion germination in the acetylsalicylic acid solution showed a reproducible increase in the frequency of cells with micronuclei (2 and 5.5 times, respectively) and double nuclei (3 and 1.5 times, respectively). The approach described herein may be applied for obtaining rapid, cost-efficient and useful supplementary data on different types of toxicity for marketed drugs as well as for drugs under development.

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract