Effects of combined exposure to modeled radiation and gravitation factors of the interplanetary flight: Monkeys' cognitive functions and the content of monoamines and their metabolites; cytogenetic changes in peripheral blood lymphocytes.

In a study on primates (Macaca mulatta), neurobiological and radiobiological effects have been studied of the synchronous combined action of 7-day antiorthostatic hypokinesia and exposure of the monkeys' head first to γ-rays during 24 h and then to accelerated C ions. The neurobiological effects were evaluated by the cognitive functions which model the basic elements of operator activity and the concentration of monoamines and their metabolites in peripheral blood. The radiobiological effects were evaluated by the chromosomal aberration and DNA double-strand break (DSB) yield in peripheral blood lymphocytes.

Increase of mtDNA number and its mutant copies in rat brain after exposure to 150 MeV protons.

Proton beam therapy is widely used for treating brain tumor. Despite the efficacy of treatment, the use of this therapy has met some limitations associated with possible damage to normal brain tissues located beyond the tumor site. In this context, the exploration of the harmful effects of protons on the normal brain tissues is of particular interest.

Author Correction: Proton irradiation: a key to the challenge of N-glycosidic bond formation in a prebiotic context.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Proton irradiation: a key to the challenge of N-glycosidic bond formation in a prebiotic context.

The formation of nucleosides in abiotic conditions is a major hurdle in origin-of-life studies. We have determined the pathway of a general reaction leading to the one-pot synthesis of ribo- and 2'-deoxy-ribonucleosides from sugars and purine nucleobases under proton irradiation in the presence of a chondrite meteorite. These conditions simulate the presumptive conditions in space or on an early Earth fluxed by slow protons from the solar wind, potentially mimicking a plausible prebiotic scenario.

Exposure to (12)C particles alters the normal dynamics of brain monoamine metabolism and behaviour in rats.

Planning of the deep-space exploration missions raises a number of questions on the radiation protection of astronauts. One of the medical concerns is associated with exposure of a crew to highly energetic particles of galactic cosmic rays. Among many other health disorders, irradiation with these particles has a substantial impact on the central nervous system (CNS).

First Evidence on the Role of Heavy Ion Irradiation of Meteorites and Formamide in the Origin of Biomolecules.

Formamide (NHCHO) has been irradiated in condensed phase at 273 K by B-boron beams in the presence of powdered meteorites of the chondrite and stony-iron types. Relative to the controls (no radiation or no catalysis), a variegate panel of compounds was observed, including purine and pyrimidine nucleobases (uracil, cytosine, adenine, and guanine), nucleobase analogues, heterocycles, and carboxylic acids involved in metabolic pathways. The presence of amino imidazole carbonitrile (AICN), 4,6-diamino purine (4,6-DAP) and 2,4-diamino pyrimidine (2,4-DAPy) among the observed products suggests the occurrence of an unified mechanism based on the generation of radical cyanide species (•CN).

Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation.

Liquid formamide has been irradiated by high-energy proton beams in the presence of powdered meteorites, and the products of the catalyzed resulting syntheses were analyzed by mass spectrometry. Relative to the controls (no radiation, or no formamide, or no catalyst), an extremely rich, variegate, and prebiotically relevant panel of compounds was observed. The meteorites tested were representative of the four major classes: iron, stony iron, chondrites, and achondrites.

Inter-chromosomal variation in aberration frequencies in human lymphocytes exposed to charged particles of LET between 0.5 and 55 keV/μm.

Purpose: To investigate the distribution of chromosomal aberrations in chromosomes 2, 8 and 14 induced by charged particles, using the fluorescence in situ hybridisation (FISH) technique.

Methods: Irradiation of peripheral blood from six healthy volunteers (four male and two female) was performed at the accelerators of the Joint Institute for Nuclear Research (JINR) in Dubna (Russia). Whole blood samples were irradiated with 2 and 3 Gy of protons (170 MeV/nucleon (n), linear energy transfer (LET) ≈ 0.