3-Carbamoyl-2,2-dimethyl-cyclo-pentane-1,1-dicarb-oxy-lic acid.

In the title compound, C(10)H(15)NO(5), the five-membered cyclo-pentane ring has an envelope conformation, with four atoms lying in a plane (mean deviation = 0.0213 Å), while the fifth atom deviates from this plane by 0.626 (2) Å.

[The effect of adding Laminaria japonica to food on the long-term effects when combined with radiation injury].

Irradiation of rats by 131I (10 Gy) incorporated in the thyroid and by 137Cs external source (6 Gy) was made. Part of animals received a ration with Laminaria that reduced a rise in frequency of leukemia, other malignant tumors and increased latent period of tumor formation.

[Study of the anticarcinogenic characteristics of the trace element, selenium, sanitary-hygienic experiment].

Enrichment of rat daily diets by 1-2 (up to 5) mg selenium increased nonspecific resistance of animals to ionizing radiation. Incidence of mammary, pituitary, and thyroid tumors as well as of leukemia were lower as compared with control animal group given no selenium.

[Dietary intake of Cs-137 and Sr-90 by the population of the Gomel region, Byelarus, 1986-1989].

The authors provide the results of measuring the content of radionuclides in foods in the first 4 years after the Chernobyl accident and the data on the diet of the population. Pollution of foods was demonstrated to decrease with time. The supply of 137Cs to the body fell 3-fold from 1986 to 1989.

[The effect of an increased dietary intake of organic selenium on the resistance of rats to ionizing radiation, aflatoxin B1 and infection].

Varying concentrations of the selenium biological compound "Selena" were tested in animals subjected to the action of extremal factors simulating those that affected the population at the territories radiocontaminated as a result of the catastrophe at the Chernobyl NPS (131I and external irradiation in falling down doses). The death rate in the group of animals that were not given "Selena" comprised 30% during 6 months after irradiation, their body mass was 120 g lower as compared to the animals in the group of biological control; among the animals given 0.03 mg of selenium/day the death rate was 4 times lower.

[Prevention of accumulation of strontium-90 in the bones by fortifying the food with fish products].

The replacement of 1/5 part of the usual ration received by non-inbred white rats for fish mass containing up to 4 g/kg Ca resulted in a sharp (by 70%) reduction of Sr-90 accumulation after its oral intake. The effect is intensified in case of normalization of the basic ration in respect to Ca content, and the lowering of the isotope accumulation level in the skeleton comprises 82% as compared to the group of animals that received the Ca-deficient ration.

[Modifying effect of the chemical components of dust on the induction of lung tumors by physical and chemical carcinogens (experimental study].

Chronic inhalation intake of benzo(a)pyrene (BP) and polonium-210 (210Po) together with aluminum oxide caused increase of tumor formation in the lungs of mice. Synergy of BP and 210Po carcinogenic effect was pointed out, it was characterized by summation and possible effect involution by tumor development rates and the duration of the latent period. BP and 210Po carcinogenic effectiveness depended on the type of dust carrier and probably on the presence of silicon dioxide and also carcinogenic metals.

[Natural background radiation: problem of radionuclide migration and biological effects].

Natural radiation background is the main contributor to radiation dose delivered to plants, animals, and man. That is why its effects are of increasing interest in radiobiology, radioecology, and radiation hygiene. The following problems are discussed: migration of main natural radionuclides in biosphere, dose formation, biological role of natural radiation background on the Earth, standards for natural radiation background, and problems of natural radiation background and biosphere evolution.