Here we present a prognostic model of horizontal spread of bacterial drug resistance genes in spacecraft crews. The model takes into account the value of gene transfer frequency during conjugation ...and mobilization of plasmids, adjusted for its variability under the influence of space flight factors, the frequency of occurrence and concentration of microbial communities, which form a pool for the propagation of antibiotic resistance genes in space flight. To develop a phenomenological model of antibiotic resistance, two stages of a scientific experiment were carried out. The first stage consisted of identifying the biotope of the nasopharynx of cosmonauts participating in the Salyut-7 space program and the number of antibiotic resistance determinants in bacteria identified in nasopharynx. The second stage of the experiment was carried out on the Russian Segment of the International Space Station and consisted in determining the values of mobilization and conjugation in space flight conditions, under normal conditions on Earth and in post-flight research. In these investigations the archive data was chosen, since while Salyut flights only few visiting crew missions were undertaken, so the flights were mostly isolated and because of that were more likely as planned interplanetary missions and thus are of most our interest.
The phenomenological model, based on the experiments, made it possible to predict a multiple decrease in antibiotic resistance in space conditions, against the background of increased resistance of R-plasmids.
•The model of bacterial antibiotic resistance AR in isolated spaces has been created.•The model takes into account the processes of plasmid conjugation, mobilization.•The model was used AR of microflora under the space conditions (USSR-Salyut 7).•It was shown that AR of bacteria in space is 2.6 less than on Earth’s conditions.
The composition of GET 39-2021 State primary standard of units of volumetric activity of radioactive aerosols, radon, thoron, and radon flux density is presented. Methods for reproducing and ...transferring the units of volumetric activity of radioactive aerosols, radon, thoron, and radon flux density are described. Possible sources of error are identified, and their quantitative assessment is performed. The metrological characteristics of GET 39-2021 are provided. GET 39-2021 ensures the uniformity of measurements of the volumetric activity of radioactive aerosols, radon, thoron, and radon flux density in various fields, including the nuclear industry, at enterprises for the extraction and processing of nuclear raw materials, etc. In the nuclear industry, GET 39-2021 can be used to ensure the radiation protection of personnel and the environment during the construction and commissioning of new-generation nuclear reactors.
The review examines the role of domestic space medicine and physiology in space exploration and emphasizes that domestic space medicine will focus on biological, physiological, and psychological ...aspects of humans. The main task of specialists in the field of space medicine and physiology is to prepare for future stages of manned astronautics, using existing accumulated experience, new developments, and assessing the forecast of probable events and situations that the human will inevitably encounter in this new world.
The mechanoelectrical feedback in the heart is based on the work of mechanically gated (MGCs) and mechanosensitive (MSCs) channels. Since microgravity alters the heart’s morphological and ...physiological properties, we hypothesized that the expression of both MGCs and MSCs would be affected. We employed RNA transcriptome sequencing to investigate changes in the gene transcript levels of MGCs and MSCs in isolated rat ventricular cardiomyocytes under control conditions and in a simulated microgravity environment. For the first time, our findings demonstrated that simulated microgravity induces alterations in the gene transcript levels of specific MGCs, such as TRPM7, TRPV2, TRPP1, TRPP2, Piezo1, TMEM63A, TMEM36B, and known MSCs, including K
2P
2.1, K
2P
3.1, Kir6.1, Kir6.2, Na
V
1.5, Ca
V
1.2, K
V
7.1. However, other voltage-gated channels and channels lacking a voltage sensor remained unaffected. These findings suggest that the altered expression of MGCs and MSCs could lead to changes in the net currents across the membrane, ultimately impacting the heart’s function.
—Spore-forming bacteria have a unique resistance to negative environmental conditions, including aggressive space factors, and are an excellent model for studying adaptation mechanisms and survival ...strategies at the molecular level. The study analyzed the genome of
Bacillus velezensis
, which remained viable after a 2-year exposure in outer space on the outer surface of the ISS as part of the Test space experiment. A comparative analysis of the draft genomes of the exhibit strain and the ground control did not reveal significant changes; the average nucleotide identity was 99.98%, which indicates the ability of microorganisms to maintain genome stability in space conditions, due to both increased stress resistance of bacterial spores and efficient operation of the system of repair of accumulated changes. The study of a single nucleotide polymorphism in the genome of
B. velezensis
revealed nine point substitutions, three of which are in intergenic regions, six in protein-coding genes, three of them are missense mutations, two nucleotide deletions leading to a shift in the reading frame, and one synonymous substitution. The profiles of the housekeeping genes were determined during MLST typing and it was found that the allelic profiles obtained for
B. velezensis
T15.2 and 924 strains do not correspond to any of the previously described sequence types.The presented results indicate the ability of
B. velezensis
bacteria to maintain the viability of spores and the integrity of the genome for a long time under extreme conditions of outer space, which is important for the problem of planetary protection, as well as the potential possibility of performing biotechnological processes based on
B. velezensis
during space exploration.
We analyse an engineering model for a self-consistent calculation of the growth of an oxide film in circulation circuits with a heavy liquid metal coolant and concentrations of impurities (oxygen, ...iron, magnetite) from the point of view of possible uncertainty in determining the activity of oxygen. The modelling of thermohydraulic and physicochemical processes is based on solving the associated three-dimensional equations of hydrodynamics, convective-diffusive transport, and the formation of chemically interacting impurity components in the coolant volume and on the surface of steels. Model calculations of the influence of the uncertainty of oxygen activity on the rate and integral yield of iron, which under the given conditions of the oxygen regime after interaction with oxygen determines the appearance of magnetite. It is numerically demonstrated that in the saturation mode there is a model-independent characteristic, which is determined by the parabolic constant and thickness of the oxide film characteristic of steel. Understanding these processes is highly important for justification of loops with HLMC and steadiness of structural materials that are in contacts with HLMC.
•Six candidates for markers of maintaining homeostasis in hypodynamia were found•COL6A1 and COL15A1 may be biomarkers of the autonomic balance in the regulatory mechanisms•COL6A1 may be a marker of ...the aging process
The study of proteins - potential markers, associated signal transduction pathways, and their targets - provides a new understanding of the fundamental mechanisms occurring at the level of regulatory processes in the cardiovascular system (CVS), especially in space flight, as well as in model experiments that reproduce its individual effects on the human body. The article presents the results of studies in an experiment with 120-day isolation within the framework of the SIRIUS project in which 6 volunteers aged 28 to 44 years (three men and three women) participated. SIRIUS (Scientific International Research in Unique Terrestrial Station) is the international research project, which studies the issues of biomedical and psychological support of long-term manned space flights. The possible involvement of collagen different types, an extracellular matrix protein, in the mechanisms of autonomic regulation of the CVS was studied. Using chromatic mass spectrometry in urine samples and analysis of heart rate variability, we have established that the extracellular matrix collagen, which is present, in particular, in the structure of the blood vessel wall, are markers associated with the modulating effect of the autonomic nervous system on the regulatory mechanisms of blood circulation. We hypothesized that these proteins may be a biomarker of the autonomic balance in the regulatory mechanisms of the circulatory system. In addition, these proteins can also be markers of the aging process, which increases the risks of developing autonomic dysfunction of the cardiovascular system (dominance of sympathicotonia) and changes in the quality of the tissue of the heart muscle and blood vessels, provoking the development of prenosological conditions and diseases of the cardiovascular system.
This article, based on a report presented at the Scientific Session of the Russian Academy of Sciences, highlights the history of the formation of space medicine, its theoretical foundations, and the ...role of scientists of the Academy of Sciences in the preparation and implementation of the first manned flight into space. The achievements of domestic specialists in space physiology, biology, and medicine promoting the development of manned cosmonautics are considered. Examples are given of the implementation of the results of space research, as well as instruments and devices for medical support of space crews, into practical health care. The problems of medical support of future interplanetary flights and the ways of their solution are analyzed.
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