[Cataractogenic action of accelerated carbon ions with energies of 300 MeV/nucleon]. / Kataraktogennoe deistvie uskorennykh ionov ugleroda s énergiei 300 MéV/nuklon.

The influence of carbon ions of 300 MeV/nucleon on the incidence of lenticular opacity has been studied on mice. The cataractogenic efficiency of low carbon ion doses (0.003 to 0.5 Gy) is higher than that of gamma-radiation. The threshold dose of carbon ions is 0.05 Gy. The RBE ratios vary from 30.4 to 11.1 as the period of the postirradiation observation increases from 20 to 50 weeks.

Radiobiological experiments with plant seeds aboard the biosatellite Kosmos 1887.

The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied provided with various protective measures: the seeds were located inside the satellite and in open space, protected with aluminium foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminium foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can be thus regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

[Effect of charged particles of relativistic energy on the number of chromosome aberrations in human blood lymphocytes. Dose-response relationship and the RBE of protons, deuterons and helium ions]. / Vliianie zariazhennykh chastits reliativistskikh énergii na chastoty khromosomnykh aberratsii v limfotsitakh krovi cheloveka. Zavisimost' doza-éffekt i OBE protonov, deitonov i ionov geliia.

In experiments with human blood lymphocyte culture exposed to fast protons, deuterons and helium ions the frequency and types of chromosome aberrations have been studied. Fast charged particles of a relativistic energy are shown to have a pronounced harmful effect resulting in a sharply increased formation of exchange chromosome aberrations as compared to that produced by gamma-radiation. The RBE coefficients of the particles under study have been determined: their values vary depending on the type of radiation and the tests used.

[Effect of radiations with varying linear energy transfer on the skin of mice]. / Deistvie na kozhu myshei izluchenii s razlichnoi lineinoi peredachei énergii.

Experiments were carried out to measure the time and severity of the radiation reaction of the skin of mice exposed to X- and gamma-radiations, protons with energies of 645 and 50 MeV as well as accelerated helium ions at doses of 200 to 4000 rad. It was found that relative biological effectiveness coefficients of 645 and 50 MeV protons were 1.0 and those of helium ions were 1.3 for the skin reaction at early and late stages of observation. No significant difference in the time of manifestation of radiation-induced skin lesions as related to radiations with various LET was detected.