RESUMO
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.
Assuntos
Adaptação Fisiológica , Astronautas , Voo Espacial , Imunidade Adaptativa , Peso Corporal , Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Dano ao DNA , Metilação de DNA , Microbioma Gastrointestinal , Instabilidade Genômica , Humanos , Masculino , Homeostase do Telômero , Fatores de Tempo , Estados Unidos , United States National Aeronautics and Space AdministrationRESUMO
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.
