ABSTRACT
To understand the health impact of long-duration spaceflight, one identical twin astronaut was monitored before, during, and after a 1-year mission onboard the International Space Station; his twin served as a genetically matched ground control. Longitudinal assessments identified spaceflight-specific changes, including decreased body mass, telomere elongation, genome instability, carotid artery distension and increased intima-media thickness, altered ocular structure, transcriptional and metabolic changes, DNA methylation changes in immune and oxidative stress-related pathways, gastrointestinal microbiota alterations, and some cognitive decline postflight. Although average telomere length, global gene expression, and microbiome changes returned to near preflight levels within 6 months after return to Earth, increased numbers of short telomeres were observed and expression of some genes was still disrupted. These multiomic, molecular, physiological, and behavioral datasets provide a valuable roadmap of the putative health risks for future human spaceflight.
Subject(s)
Adaptation, Physiological , Astronauts , Space Flight , Adaptive Immunity , Body Weight , Carotid Arteries/diagnostic imaging , Carotid Intima-Media Thickness , DNA Damage , DNA Methylation , Gastrointestinal Microbiome , Genomic Instability , Humans , Male , Telomere Homeostasis , Time Factors , United States , United States National Aeronautics and Space AdministrationABSTRACT
Infrared absorption spectra in the C[triple bond]N stretching frequency region were collected for methyl thiocyanate, the simplest model aliphatic thiocyanate, in several common solvents to establish the dependence of the C[triple bond]N spectral band of aliphatic thiocyanate on its local solvation environment. Systematic changes in the C[triple bond]N bandwidth indicate that it reports on fast solvation dynamics. Anomalous asymmetry and temperature dependence of the C[triple bond]N band in fluorinated alcohol solvents indicates that these solvents participate in formation of a discrete hydrogen-bonded complex with the C[triple bond]N end of methyl thiocyanate. These observations indicate that the C[triple bond]N band of thiocyanate could be an effective site-specific probe of both specific hydrogen bonding and local dynamics in more complex systems, such as peptides and proteins.