Abstract: The review is devoted to the molecular mechanisms of bone resorption with recruitment of neuromediators and neurotransmitters executing the ladder processes of neuronal regulation and directly stimulating serotonergic, adrenergic, glutamatergic and GABA-ergic receptors of osteoblasts and osteoclasts. Microgravity-induced elevation of the sympathetic nervous system tone is considered a likely factor in the increase in bone resorption rate during long-duration space flight.

Abstract: Regeneration of ionite artificial soil (AS) in root modules (RM) of conveyor-type space greenhouses should be proceeded by removal of root residues without disruption of the AS capillary-porous structure. The proposed method consists of two stages of root residues destruction. On the first stage, AS treatment by 0.7% an alkali water solution with added 0.7% hydrogen peroxide over 3.5 hours in a thermal-insulation container at 95 +/- 4 degrees C reduces root residue mass up to 60%. Specific energy cost of SHF pulses to maintain the required temperature is 1 W x hr for cleaning 1 g and AS sterilization from saprotrophs. On the second stage, AS undergoes saturation with a liquid anaerobic medium for 7-day cultivation of thermophilic Clostridium thermocellum at 55 degrees C. Seven days of bio-engineering regeneration enables removal of 90% root biomass. Residual products of fermentation have a stimulating effect on seed germination and subsequent plant growth. Bio-engineering testing of regenerated AS with cultivation of leaf cabbage Brassica chinensis L. attested to suitability of the technology for extension of AS useful life.

Abstract: The paper presents the results of an investigation with mice subjected to isolated and successive exposure to a blend of chemical agents (acetone, ethanol, acetaldehyde) at MPC levels defined for piloted space vehicles followed by fractionated gamma-irradiation by daily 1 cGy (30 cGy total). The selected chemicals are the primary contributors to total air contamination and present in the prioritized list of compounds to be monitored to ensure air quality on piloted space vehicles. Radiation levels were determined with allowance for mice radiosensitivity to simulate the actual absorbed dose accumulated by crewmembers of orbital mission of up to a year in duration (10 cGy). Based on the findings in the hematopoietic system and erythrocyte biochemistry, energy exchange and redox parameters, pre-irradiation exposure to chemical agents within the MPC limits accentuated radiosensitivity gravely and, therefore, made mouse organism less tolerant to radiation. It was shown that adaptation of the hematopoietic system calls forth activation and significant straining of regulatory mechanisms equally in opposing to a single factor or combination of chemical and radiation exposure. The marked tension of these mechanisms persisted till day 30 of recovery.