[Biological effects of space flight on several opportunistic pathogenic bacteria and biodestructive fungi].

OBJECTIVE: To investigate biological effects of space flight on several conditional pathogenic bacteria and biodestructive fungi. METHOD: Several potentially pathogenic or biodegrading microorganisms, including bacteria, actinomyces and fungi, were carried on-board spacecraft for 7 d. Some of the biological characteristics were studied by using general microbial test technology after recovery. RESULT: In space condition, survival and growth rate were promoted, and soluble pigments were produced, while morphological properties were changed differently. The antibiotic-sensitivity of certain strains decreased, while most of them showed no changes. CONCLUSION: The reproduction ability and growth rate of these microorganisms are promoted after being carried into space, and morphological differentiation increase. The resistance to antibiotics is stable.

[Effects of 21 d -6 degrees head down bed-rest on pulmonary gas distribution and little airway function].

OBJECTIVE: To probe the effect of 21 d -6 degrees head down bed-rest (HDBR) on pulmonary gas distribution and little airway function. METHOD: The indices of the pulmonary gas distribution and little airway function (delta N2, CV, CV/VC%, LCI) were measured in 16 healthy male subjects before, during and after 21 d -6 degrees HD-BR. RESULT: Comparing with before and early days of HDBR, recovery supine delta N2 increased significantly. CV increased significantly only on the first day of HDBR, and changes of CV/VC% were same as CV. The changes of LCI were not significant. CONCLUSION: The indices of pulmonary gas distribution were affected by 21 d -6 degrees HDBR. Pulmonary gas distribution was more uneven during and after 21 d -6 degrees HDBR.

[Past, present and future development of the project of manned space medico-engineering in China].

Based on the research work of manned space medico-engineering at different stages of its development in China, the formation and development of the subject was summarized. The relations among the main fields of space medico-engineering, that is, depend on each other for existence, influence, co-operation and infiltration in the system, were discussed. Considering the ongoing tasks of manned space flight in China, directions and contents of research work of manned space medico-engineering were pointed out. And to make the ongoing tasks more successful, methods of development of the subject were put forward, namely, teaching, research and project should promote each other and develop together.

[Safety and reliability verification for manned spacecraft crew support facilities].

OBJECTIVE: To verify reliability and safety of the crew support facilities on board manned spacecraft. METHOD: Several comprehensive qualitative and quantitative projection verification technique, such as analysis, check, demonstration, tests and reliability assessment, were used. RESULT: Work-items that were specified in the reliability and safety program were realized. Assurance measures for safety and reliability critical items were available. FMEA and SHA and FTA were brought in all around. Safety and reliability on equipment levels and system levels was fully carried out. CONCLUSION: The facility safety and reliability achieved design specification and met the requirements of spaceflight tests for manned spacecraft.

[A study on training method for increasing adaptability to blood redistribution in human].

OBJECTIVE: To verify validity of the increase in adaptability of blood redistribution in human body with repeated body position change training and to find preferable training method for increasing astronaut's adaptability of blood redistribution. METHOD: Twelve subjects were randomly divided into group A and B. Six subjects in each group were trained with mode A and B repeated position change (9 times in 11 d) respectively. Their head-down tilt (HDT -30 degrees/30 min) tolerance and orthostatic tolerance were determined before and after training to verify training effects. RESULT: 1) Two kinds of repeated body position change training modes increased all subjects' HDT tolerance. Compared with pre-training, during HDT test subjects' symptom scores in group B were significantly lower than those in group A (P<0.05) and after training decreasing magnitude of heart rate in group B increased significantly (P<0.01). Then mode B to be preferable training method in increasing HDT tolerance was suggested. 2) Two kinds of training modes improved all subjects' orthostatic tolerance. Compared with pre-training, during orthostatic tolerance test increasing magnitude of mean arterial blood pressure in group B increased significantly (P<0.05) and a trend of increasing magnitude of heart rate in group B was appeared smaller than in group A (P<0.10). Mode B to be preferable training method in increasing orthostatic tolerance was suggested too. CONCLUSION: Repeated body position change training could increase adaptability to blood redistribution in human body. Mode B was preferable training method and would be hopeful to be used in astronaut training.

[Effects of repeated body position change training for human orthostatic tolerance].

OBJECTIVE: To verify the validity that repeated position change training can increase human orthostatic tolerance and to explore its mechanism. METHOD: Six subjects were trained with repeated position change for 11 d according to a protocol of alternative head-down and head-up tilts, each set of training lasted for about 35 min. Their orthostatic tolerances were determined before and after training. RESULT: Compared with the data before training, subjects' symptom scores during orthostatic tolerance test after training decreased significantly (4.50 +/- 1.05 vs. 2.83 +/- 1.60, P<0.05), magnitude of the increased heart rate increase lowered significantly [(29.3 +/- 4.3) bpm vs. (13.5 +/- 7.5) bpm, P<0.01], magnitude of mean arterial blood pressure augmentation increased significantly [(4.8 +/- 4.4) mmHg vs. (9.0 +/- 3.0) mmHg, P<0.05] and cardiovascular response index decreased significantly (34.42 +/- 5.00 vs. 22.33 +/- 8.27, P<0.01). In brief, the responses to orthostatic stress were improved after training. CONCLUSION: Repeated alternative body position change training can increase human orthostatic tolerance. This kind of training is promising for pilot, especially astronaut training.

[Changes of cardiac kinetics during various stages of space flight].

Arterial blood pressure is dependent on ordinary cardiac function in human beings. Cardiac kinetics serves as important cardiovascular parameters during various stages of space activities. Although the reports about cardiac kinetics were not always in consistency during spaceflight, obvious changes during orthostatic stress after spaceflight were commonly observed. The mechanisms of orthostatic intolerance after spaceflight remain to be clarified, and the effects of changes of cardiac kinetics remain to be discussed. This paper briefly reviews the reports on cardiac kinetics during various stages of space activities and the researches on the mechanism of orthostatic intolerance after spaceflight.