Heart rate dynamics during long-term space flight: report on Mir cosmonauts
No abstract available
SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
No abstract available
There is evidence that weightlessness and radiation, two elements of the spaceflight environment, can lead to detrimental changes in human musculoskeletal tissue, including bone loss and muscle atrophy. This bone loss is thought to be brought about by the increased activity of bone-resorbing osteoclasts and functional changes in bone-forming osteoblasts, cells that give rise to mature osteocytes. Collectively, our research team aims to understand the molecular mechanisms underlying the responses of mammalian tissue to the spaceflight environment using earth-based animal and cellular models. The overarching goal is to identify molecular targets to prevent tissue decrements induced by spaceflight and earth-based scenarios of radiotherapy, accidental radiation exposure and reduced mobility. In this talk, I will provide an overview of skeletal and cardiovascular responses to spaceflight and will highlight our research progress on understanding the role of reactive oxygen species (ROS) signaling in skeletal responses to radiation and simulated weightlessness.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Absolute electron intensities in the earths outer radiation zone
Explore the source record for details and available documents.
Individual caged mice susceptibility found greater than groups to toxic effect of d- amphetamine
External biosensor using optical backscatter for continuous determination of blood oxygenation in humans and animals
Decreased intensity of myocardial respiration and oxygen metabolism as age factors
Correlation between cardiographic measurement values obtained by impedance, indicator flow, or pressure gradient observations on humans
Cardiac output from transthoracic impedance variations
Explore the source record for details and available documents.
Gap in atrioventricular conduction in humans by catheter technique for recording electrical activity of His bundle
Atrial and ventricular dimensional analysis in animals and man, discussing angiocardiographic, biplane, X ray, indicator dilution, radioisotopic and noninvasive methods
Ultraminiature catheter cables that are stiff enough for intravenous insertion yet flexible at the tip, sterilizable, and economical are fabricated entirely from commercially available parts. Assembly includes air passageway for reference pressures and coaxial cable for transmission of signals from the tip of catheter.
Basic steps in the acquisition and reconstruction of cardiac dimensions obtained from angiocardiograms for spatial reconstruction and analysis are described, and example applications include a reconstruction of the human left ventricle and a study of the motion of the free wall of the right ventricle in a dog. Computer analysis of the spatial motion of implanted tantalum markers is discussed along with corrections for distortion and magnification incurred in the process. Graphics display of three-dimensional ventricle models is examined, and future improvements in angiocardiographic studies are considered.
Electronics for this system may be chosen so that complete calculation and display may be accomplished in a few milliseconds, far less than even the fastest heartbeat interval. Accuracy may be increased, if desired, by using higher-frequency timing oscillator, although this will require large capacity registers at increased cost.
Explore the source record for details and available documents.