[Biological effectiveness of pulsed and continuous neutron radiation for Saccharomyces yeast cells].

The article presents the data on biological effectiveness of neutrons generated by the pulsed reactor BARS-6 (dose-rate up to 6 x 10(6) Gy/s) in comparison with fast neutrons of the reactor BR-10 (dose-rate 6.3 x 10(-2) Gy/s). It was shown for yeast cells of a wild type that the RBE values of pulsed neutrons varied insignificantly with a dose (2.

[Comparative study of chromosome aberration formation in lymphocytes culture under pulsed and continuous neutron irradiation].

Frequencies of chromosome aberration induced by prolong (continuous) neutron radiation (dose-rate 0.17 Gy/min) and pulsed neutron radiation with ultra-high dose-rate (1-4) x 10(5) Gy/s have been studied in human blood lymphocytes at G0-stage. It was demonstrated that cytogenetic efficiency of pulsed neutrons (after the substraction of approximately 50% gamma-component from the total dose) was 2 times higher than that of continuous neutron radiation.

[Current problems of neutron radiobiology].

A brief review of up-date problems of neutron radiobiology, related to neutron therapy development and setting up of radiation safety standards for neutrons, is present. The main attention is paid to the effects of combined gamma-neutron irradiation, peculiarities of reactor neutrons biological action and new approaches in neutron capture therapy. On the basis of own and literature data the results of cellular and whole-body studies as well as the applicability of biophysical modelling for description and interpretation of experimental data are discussed.

[Technological problems in use of fast reactors for radiotherapy of patients with malignant tumors].

The authors discuss the technological problems associated with the use of fast neutrons in radiotherapy of cancer patients and outline the approaches to the solution of these problems. The state of the art is assessed. Physical and radiobiological prerequisites for the use of fast reactors for radiotherapy of patients with malignant tumors are analyzed.

[Biophysical models of the formation of radiation-induced chromosome aberrations].

The brief analysis of the development of biophysical models describing the formation of chromosome aberrations is given. It is shown that, though the target theory is obsolete and does not correspond to modern radiobiological knowledge, however hit and target principles are still the basic radiobiological concepts. Three main directions of the development of biophysical models are submitted; their shortcomings and possible ways of perfection of the models are specified.