No abstract available.
Centrifugation ; Weightlessness

The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures against such effects. In this paper, we described the development of countermeasure systems in the Chinese space program. To emphasize the need of the Chinese space program to implement its own program for developing countermeasures, we reviewed the literature on the negative physiological effects of weightlessness, the challenges of completing missions, the development of countermeasure devices, the establishment of countermeasure programs, and the efficacy of the countermeasure techniques in American and Russian manned spaceflights. In addition, a brief overview was provided on the Chinese research and development on countermeasures to discuss the current status and goals of the development of countermeasures against physiological problems associated with weightlessness.
China ; Humans ; Program Evaluation ; Space Flight ; Weightlessness ; Weightlessness Simulation

Weightless environment is a rare phenomenon on the ground where the interactions among cells and internal cellular structures disappear or become weakened. Studies on the biological features and molecular expression of tumors cells in weightlessness condition may provide new clues to the tumor initiation, process, diagnosis, and therapy.
Humans ; Neoplasms ; pathology ; Tumor Cells, Cultured ; Weightlessness ; Weightlessness Simulation

OBJECTIVE: To investigate whether collagen peptides can improve the immune functions of mice under the condition of simulated weightlessness. METHODS: Mouse tail-suspension model was used to simulate the effects of weightlessness. Tail-suspended mice were intraperitoneally injected with 600 mg collagen peptides per kilogram body weight once a day for 10 days. Then, the mice were killed, and white blood cells were counted and classified. Lymphocyte subsets and T lymphocyte proliferations in spleens were analyzed. RESULTS: Compared with normal control group, total and differential count of leukocytes, lymphocytes, T cells，CD4 and CD8 T cells, B cells and NK cells, and splenic T lymphocyte proliferation all decreased in the weightlessness simulated mice (P＜0.05). Except for NK cells, the above-mentioned parameters were increased after administration of collagen peptides, and some of the parameters were recovered to the levels of normal control mice (P＜0.05). CONCLUSION Collagen peptides can effectively improve peripheral blood lymphocyte distributions and T lymphocyte proliferations of mice under the condition of simulated weightlessness. This study nay provid the experimental basis for improvement of immune functions of astronauts.
Animals ; CD8-Positive T-Lymphocytes ; Cell Proliferation ; Collagen ; Lymphocyte Count ; Mice ; Peptides ; Spleen ; Weightlessness ; Weightlessness Simulation

Exposure to thermal environment is one of the main concerns for manned space exploration. By focusing on the works performed on thermoregulation at microgravity or simulated microgravity, we endeavored to review the investigation on space thermal environmental physiology. First of all, the application of medical requirements for the crew module design from normal thermal comfort to accidental thermal emergencies in a space craft will be addressed. Then, alterations in the autonomic and behavioral temperature regulation caused by the effect of weightlessness both in space flight and its simulation on the ground are also discussed. Furthermore, countermeasures like exercise training, simulated natural ventilation, encouraged drink, etc., in the protection of thermoregulation during space flight is presented. Finally, the challenge of space thermal environment physiology faced in the future is figured out.
Aerospace Medicine ; Body Temperature Regulation ; Environment ; Exercise ; Humans ; Space Flight ; Weightlessness ; Weightlessness Simulation

It has been shown that the minimum gravity exposure requirements vary greatly among different physiological systems. A preliminary comparison between two extremes, vessels vs. bones, shows that not only the mechanostat at the tissue level differs greatly, but also the bone loss during weightlessness may also involve calcium deposition-resorption changes. It seems that the surprising efficacy of intermittent artificial gravity (IAG) is due to the vascular tissues possessing a strong resilience or "memory" function toward restoring their original pre-stress and tensegrity state at the 1 G environment. It appears that the bone tissue is related to a more complex tensegrity paradigm involving both osteoblasts and osteoclasts, and a longer half time for calcium deposition-absorption. Cell-level models (CellML) for calcium dynamics is currently available. We hope that the Physiome Project can use this modeling framework to help interpret the resistance of bones to IAG and to evaluate whether the "intermittent" or "continuous" AG scheme should be adopted eventually for future exploration-class spaceflight.
Animals ; Bone and Bones ; Calcium ; Gravity, Altered ; Osteoblasts ; Osteoclasts ; Rats ; Weightlessness ; Weightlessness Simulation

Cardiac remodeling is the heart's response to external or internal stimuli. Weightlessness/simulated weightlessness leads to cardiac atrophy and heart function declining. Understanding the mechanism of cardiac atrophy under weightlessness is important to help astronaut recover from unloading-induced cardiovascular changes after spaceflight. Unloading-induced changes of hemodynamics, metabolic demands and neurohumoral regulation contribute to cardiac atrophy and function declining. During this process, Ca(2+)-related signaling, NF-κB signaling, ERK signaling, ubiquitin-proteasome pathway and autophagy are involved in weightlessness-induced cardiac atrophy. This article reviews the underlying mechanism of cardiac atrophy under weightlessness/simulated weightlessness.
Atrophy ; Heart ; Heart Diseases ; Hemodynamics ; Humans ; NF-kappa B ; Space Flight ; Weightlessness ; Weightlessness Simulation

Bioseperation, cell cultivation and cell electrofusion are three main biological processes in space laboratories. Microgravity is free from the influences of convection and sedimentation. Therefore, it is an ideal realm for cell electrofusion and hence it can be used in the research of monoclonal antibody, cross breeding and microgravity biology. This paper reviews the research of cell electrofusion under microgravity, including the changes of cytoskeleton and the mechanism of cell electrofusion.
Animals ; Cell Culture Techniques ; Cell Fusion ; methods ; Electric Stimulation ; Electroporation ; methods ; Mice ; Microelectrodes ; Weightlessness ; Weightlessness Simulation

Space flight experiments have suggested that microgravity can affect cellular processes in microorganisms. To simulate the microgravity environment on earth, several models have been developed and applied to examine the effect of microgravity on secondary metabolism. In this paper, studies of effects of space flight on secondary metabolism are exemplified and reviewed along with the advantages and disadvantages of the current models used for simulating microgravity. This discussion is both significant and timely to researchers considering the use of simulated microgravity or space flight to explore effects of weightlessness on secondary metabolism.
Humans ; Metabolism ; physiology ; Models, Theoretical ; Space Flight ; Weightlessness Simulation

As it is difficult to perform biological study in the actual space, several researchers have tried to develop methods that could 'mimic' microgravity condition on Earth. During the free fall of the aircraft, so-called 'parabolic flight', objects in a plane could experience weightlessness during a short period of time (approximately 20 to 30 seconds). We first reviewed former studies using parabolic flight in a variety of research filed including vestibular, neurologic, cardiovascular, musculoskeletal and immune system. We also investigated the actual conditions of biologic research using parabolic flight in Korea, by performing a questionnaire survey for 19 experts in space biology.
Aerospace Medicine ; Aircraft ; Biology ; Immune System ; Korea ; Weightlessness