physiology and space medicine (astrobiology)
maryam salavatifar
Volume 17, Issue 1 , March 2024, , Pages 63-71
Abstract
Earth's gravity is one of the forces that constantly affects living organisms. It's changes can affect organisms behavior and performance. Study of such effects can lead to the discovery of new practical methods. Heavy metal toxicity have a lot of risks to human health. They sometimes act as a pseudo ...
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Earth's gravity is one of the forces that constantly affects living organisms. It's changes can affect organisms behavior and performance. Study of such effects can lead to the discovery of new practical methods. Heavy metal toxicity have a lot of risks to human health. They sometimes act as a pseudo element of the body and they may even interfere with metabolic processes. Cadmium as one of the most hazardous heavy metals, cause defects in DNA repair following the induction of oxidative stress, DNA damage and may lead to cancer. Several methods have been introduced to remove heavy metals from drinking water. Bioremoval by probiotic is one of these safe methods. In this study Lactobacillus acidophilus effect on cadmium bioremoval was measured in microgravity and Mars gravity conditions. The results demonstrated that the 24-hour water treatment by L. acidophilus removed 43.77% of the cadmium concentration in the Earth gravity, 54.74% under microgravity and 54.84% in Mars gravity. Statistical analysis showed that L. acidophilus was effective in cadmium bioremoval and this ability was maintained even with gravity changes. Therefore, this bacterium can be used to remove heavy metal pollution during space missions in order to maintain the health of astronauts.
physiology and space medicine (astrobiology)
Vajihe Zarrinpour; Zahrs Hajebrahimi
Volume 15, Issue 4 , December 2022, , Pages 89-96
Abstract
A study of the effect of microgravity on the endothelial progenitor cells is useful both in understanding cardiac changes in astronauts and in using microgravity as angiogenic stimuli. The aim of the present study was to investigate the effect of microgravity on VEGFR-2 and CD34 angiogenesis markers. ...
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A study of the effect of microgravity on the endothelial progenitor cells is useful both in understanding cardiac changes in astronauts and in using microgravity as angiogenic stimuli. The aim of the present study was to investigate the effect of microgravity on VEGFR-2 and CD34 angiogenesis markers. Following extraction of progenitor cells from peripheral blood and its confirmation, gene expression was assessed by real-time PCR, and cell viability was assessed by MTT assay. The extracted cells were endothelial progenitor cells in terms of shape and surface markers CD31 and CD144. Microgravity increased the VEGFR-2 gene expression by 3.5 times after 24 hours. CD34 expression increased by 50% after 3 h but reached control level after 24 hours. Microgravity appears to have a positive effect on the expression of angiogenic markers and stimulation of endothelial progenitor cells, and it may be used as a new environment to differentiate these cells into blood vessels and to treat heart disease.
physiology and space medicine (astrobiology)
Narjes Rahmanian; Azadeh Hekmat; Zahra Hajebrahimi
Volume 15, Issue 2 , June 2022, , Pages 81-92
Abstract
Muscle atrophy is one of the problems that astronauts face after returning to earth. Myostatin is a known negative regulator of muscle growth. This study aimed to investigate the effects of simulated microgravity condition on mouse myotube cells (C2C12) growth and the myostatin gene expression. The morphological ...
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Muscle atrophy is one of the problems that astronauts face after returning to earth. Myostatin is a known negative regulator of muscle growth. This study aimed to investigate the effects of simulated microgravity condition on mouse myotube cells (C2C12) growth and the myostatin gene expression. The morphological studies and MTT cytotoxicity assay showed no significant alternation in cells after 48h simulation microgravity, however, after 72h ~40% of cell death accrued (p<0.05). The AO/PI staining and DNA fragmentation analysis confirmed this observation too. Analysis of the gene expression revealed that simulated microgravity reduced myostatin gene expression significantly after 48h (p<0.0001), however, after 72h, increased significantly (P<0.001). So, inhibition of myostatin expression in differentiated myocyte cells of astronauts could be an effective procedure to reduce skeletal muscle atrophy under microgravity condition.
physiology and space medicine (astrobiology)
Zahra Hajebrahimi; Maryam Salavatifar
Volume 14, Issue 4 , December 2021, , Pages 61-66
Abstract
Studies have shown that simulated microgravity (SMG) affects tumor cell growth and metastasis. However, the underlying molecular basis is still not known. In recent years, due to the high expression of CD44 in invasive basal breast tumors, it has been the subject of many studies. The aim of present study ...
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Studies have shown that simulated microgravity (SMG) affects tumor cell growth and metastasis. However, the underlying molecular basis is still not known. In recent years, due to the high expression of CD44 in invasive basal breast tumors, it has been the subject of many studies. The aim of present study was to investigate the gene expression of CD44 in MDA-MB-231cell line of breast cancer in microgravity conditioncell line was proliferated under normal gravity and microgravity (1 and 3 days) using 2-D clinostat. Gene expression was measured using real-time PCR technique. SMG increased gene expression (100%) after 1 day and decreased it (15%) during 3 days in comparison to the control samples. It seems that the response of cancer cells to microgravity is time dependent and simulated microgravity treatment for 3 days may have a positive effect on cancer characteristics of MDA-MB-231 cell line in order to decrease the expression of CD44.
Mohammad ghoharkhah; Behzad Alizadeh
Volume 13, Issue 4 , December 2020, , Pages 59-69
Abstract
In this numerical study, effect of magnetic field on the convective heat transfer of a magnetic fluid in an enclosure is investigated in the microgravity condition. Two cases of a single magnetic field source under the enclosure and two sources on the top and below the enclosure are considered and the ...
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In this numerical study, effect of magnetic field on the convective heat transfer of a magnetic fluid in an enclosure is investigated in the microgravity condition. Two cases of a single magnetic field source under the enclosure and two sources on the top and below the enclosure are considered and the simulations are carried out for different magnetic field intensities and magnetic source distances from the enclosure. Results indicate that the heat transfer in the microgravity is much lower than that of natural condition due to the lack of the flow vortex. Applying the magnetic field and the induced vortex due to the magnetic body force cause a significant improvement of the heat transfer. Results show that the heat transfer rate in the microgravity condition can be increases up to 6.5 times. Moreover, placing two magnetic field sources improves the main vortex and leads to 19.7 times enhancement of the heat transfer rate compared to the case of single source.
Azadeh Hekmat; Bahar Hajati; Zahra Hajebrahimi
Volume 13, Issue 1 , March 2020, , Pages 61-70
Abstract
Amount of space exploration investigation has been done to understand the variations in biological structure and function of living organisms in microgravity condition. Nowadays, the investigation of the microgravity from a nanoscale viewpoint is encouraged. Silver nanoparticles have been involved in ...
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Amount of space exploration investigation has been done to understand the variations in biological structure and function of living organisms in microgravity condition. Nowadays, the investigation of the microgravity from a nanoscale viewpoint is encouraged. Silver nanoparticles have been involved in large-scale production. In this research, the effect of simulated microgravity on DNA structure was studied. Additionally, the silver nanoparticles binding with DNA molecules under Earth gravity and simulated microgravity conditions by various spectroscopic instruments were investigated. The results displayed that microgravity simulation has created DNA structure variation. The binding affinity of silver nanoparticles to DNA altered. Microgravity initiated an alternation in size and surface charge of DNA and modified DNA structure from B to C-form. Consequently, based on our observation, microgravity can strictly affect the silver nanoparticles-DNA binding interaction. Our observations can open fascinating research lines in biology and biophysics.
physiology and space medicine (astrobiology)
maryam salavatifar; Zahra Hajebrahimi
Volume 12, Issue 1 , April 2019, , Pages 69-76
Abstract
Introduction: Gravity is one of the most important forces exposed to the organisms on the earth which affects the cells, molecules and thus the entire of organism. The purpose of this study is to investigate the effect of the simulated microgravity on the changes of RKIP metastasis suppressor gene expression ...
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Introduction: Gravity is one of the most important forces exposed to the organisms on the earth which affects the cells, molecules and thus the entire of organism. The purpose of this study is to investigate the effect of the simulated microgravity on the changes of RKIP metastasis suppressor gene expression on MDA-MB-231 breast cancer cell line.Materials and Methods: In order to impose microgravity state, cancer cells were placed on clinostat for one and three days. Then RNA was extracted from the cells and RKIP gene expression changes were evaluated by qReal time PCR.Results: The findings showed that the microgravity during one day reduced the RKIP expression level, but with continuing up to three days, the expression returned to the control level.Conclusion: By optimizing the duration of microgravity, it can be likely observed the significant effects on the RKIP gene expression changes and so that useful steps can be taken to discover the cancer mechanisms and its treatment.
A. Movafeghi; E. Yahaghi; N. Mohammadzadeh
Volume 6, Issue 2 , July 2013, , Pages 43-48
Abstract
Cosmic rays in the atmosphere can cause leukemia and other diseases in the astronauts. Changing in microgravity weight make some unwanted effects on cells of the immune system and hematopoiesis. However, the activity of the body organisms is random in different people, but it can be simulate by special ...
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Cosmic rays in the atmosphere can cause leukemia and other diseases in the astronauts. Changing in microgravity weight make some unwanted effects on cells of the immune system and hematopoiesis. However, the activity of the body organisms is random in different people, but it can be simulate by special models. There are many different models of hematopoiesis that are simulated the effect of microgravity in the bone marrow. In this study, a self-developed code is used for investigation of absorbed dose effects on declining health of the tissue, blood and lymph, due to cosmic rays in space. The simulation was implemented for different kinds of input dose to body with different time duration. This phenomenon is surveyed for two cases: with considering to effect of production and reproduction of the cells and microgravity and without considering them. The results show effect of production and reproduction of the cell and microgravity can be improve or damage of normal cell about centesimal percent. Also, it can be initiate the anemia and the leukemia on the human at long time.
M. Tahaye Abadi; H. Kashani; N. Ariaeifar
Volume 2, Issue 1 , April 2009, , Pages 25-34
Abstract
The paper presents a kinematical model for a random positioning system which simulates microgravity conditions on the ground. The random positioning system contains two frames, with an experiment platform. The frames are rotated around two perpendicular axes by a random angular velocity that it causes ...
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The paper presents a kinematical model for a random positioning system which simulates microgravity conditions on the ground. The random positioning system contains two frames, with an experiment platform. The frames are rotated around two perpendicular axes by a random angular velocity that it causes continuous changes in the orientation of experimental sample relative to the gravity’s vector. The angular velocity between random values is changed based on specific function in order to limit the generated spurious acceleration below a preselected threshold. The kinematical model yields criteria to evaluate the microgravity conditions on ground base. Such criteria are defined based on the mean values of acceleration and gravity components which are sensed by the rotating experimental sample.
