Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Weightlessness Simulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMedDate not supplied

[Metabolic changes in simulated weightlessness].

8 healthy subjects participated in 2 series of experiments on the comparative studies of two techniques of respiratory therapy employing multicomponent anesthesia during controlled lung ventilation in normal conditions and in experimental weightlessness. It has been established that experimental weightlessness, as compared to normal conditions of controlled lung ventilation, was more favourable for the maintenance of effective energy exchange in erythrocytes and tissue O2 consumption. Both techniques of respiratory therapy during controlled lung ventilation are recommended in these conditions.

Adult↗
PubMed1986

Effect of simulated weightlessness on exercise-induced anaerobic threshold.

Ventilation (VE), CO2 output (VCO2), oxygen uptake (VO2), respiratory exchange ratio (R), and the ventilatory equivalents for VO2 and VCO2 were measured during graded exercise before and after 10 d of continuous bed rest (BR) in the -6 degrees head-down position to determine the effect of deconditioning on the anaerobic threshold (AT), i.e., the highest workrate or VO2 which was achieved without evidence of lactic acidosis, as judged from the profile of ventilatory and gas exchange responses. Ten healthy male subjects performed a supine graded cycle ergometer test before (pre) and after (post) BR which consisted of 4 min of unloaded pedaling at 60 rpm followed by an increased workrate of 15 W X min-1 until volitional fatigue (max). VE, VCO2, VO2, R, VE/VO2 and VE/VCO2 were measured every 30 s and used collectively to identify the AT. Plasma (PV) and blood (BV) volumes were measured pre- and post-BR by T-1824. Following BR, VO2max decreased from 2.42 +/- 0.17 to 2.25 +/- 0.13 L X min-1 (7.0%, p less than 0.05). BR significantly (p less than 0.05) reduced the AT from 1.26 +/- 0.09 to 0.95 +/- 0.05 L X min-1 VO2; from 52.2 +/- 2.0 to 42.6 +/- 1.6% VO2max; and from 93 +/- 9 to 65 +/- 6 W. A correlation coefficient (r) of -0.11 (NS) was found between the change in VO2max and change in AT. A decrease in BV of 8.8% (p less than 0.05) was due to the 11.0% reduction in PV; red cell volume remained constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMedDate not supplied

[Psychological adaptation and work capacity during simulated weightlessness].

In two-head-down tilt studies of 7 and 8 days in duration variations in the work capacity of 24 test subjects were examined and the following stages were distinguished: habituation, stable work capacity, and unstable compensation. Among the test subjects two groups were discriminated: those with plastic and those with inert types of adaptation to a changed environment. It is concluded that the plastic-type people can better and faster adapt to head-down tilt and therefore can work more efficiently during an acute stage of adaptation to weightlessness.

Adaptation, Physiological↗
PubMed1985

Response to muscular exercise following repeated simulated weightlessness.

The effect of repeated weightlessness exposures on maximal aerobic capacity was determined when seven healthy men (36-48 yr) underwent two 10-d bedrest (BR) periods in the -6 degrees headdown position, which were separated by a 14-d recovery period. No prescribed exercise was performed by the subjects during the course of the experiment. A graded supine cycle ergometer test consisting of 4 min of unloaded pedaling at 60 rpm followed by increased work rate of 15 W X min-1 until volitional fatigue (max) was performed before (pre) and after (post) the first and second BR periods, i.e., BR1 and BR2, and again 14 d after BR2 (REC). During exercise, submaximal and maximal oxygen uptake (VO2), ventilation (VE), heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressures were measured and the gas exchange anaerobic threshold (AT) was determined. Plasma volume (Vp, T-1824) and body composition were measured pre- and post-BR1 and BR2 and following REC. Compared to the respective pre-BR control values, VO2max decreased (p less than 0.05) by 8.7% after BR1 and 5.2% after BR2 but returned to pre-BR values following 14 d REC. Submaximal and maximal HR increased (p less than 0.05) post-BR1 and BR2 but returned to pre-BR levels after REC. The AT and Vp decreased (p less than 0.05) post-BR1 and BR2 but returned to pre-BR levels after REC. Body weight increased (p less than 0.05) gradually during the experiment and did not return to control values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Forced expiration indices of the healthy human being in simulated weightlessness].

Lung volumes and forced expiratory volumes during 3-hour water immersion as well as in the upright and supine positions were measured. Water immersion up to the neck decreased the functional residual capacity, peak and maximum velocities of air flows during inspiration and expiration with various lung volumes and increased the forced expiratory time and pulmonary time constant. These changes seem to be produced by a higher inelastic resistance as well as by additional hydrostatic pressure upon the chest and abdomen. During the transfer from the upright to the supine position these changes were identical but of smaller magnitude.

Adult↗