540 results match your criteria days astronauts


Global transcriptomic analysis of a murine osteocytic cell line subjected to spaceflight.

FASEB J 2021 May;35(5):e21578

Department of Translational Dental Medicine, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.

Bone loss is a major health concern for astronauts during long-term spaceflight and for patients during prolonged bed rest or paralysis. Growing evidence suggests that osteocytes, the most abundant cells in the mineralized bone matrix, play a key role in sensing mechanical forces applied to the skeleton and integrating the orchestrated response into subcellular biochemical signals to modulate bone homeostasis. However, the precise molecular mechanisms underlying both mechanosensation and mechanotransduction in late-osteoblast-to-osteocyte cells under microgravity (µG) have yet to be elucidated. Read More

View Article and Full-Text PDF

Persistent Globe Flattening in Astronauts following Long-Duration Spaceflight.

Neuroophthalmology 2021 3;45(1):29-35. Epub 2020 Sep 3.

Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas, USA.

Posterior globe flattening has been well-documented in astronauts both during and after long-duration space flight (LDSF) and has been observed as early as 10 days into a mission on the International Space Station. Globe flattening (GF) is thought to be caused by the disc centred anterior forces created by elevated volume and/or pressure within the optic nerve sheath (ONS). This might be the result of increased intracranial pressure, increased intraorbital ONS pressure from compartmentalisation or a combination of these mechanisms. Read More

View Article and Full-Text PDF
September 2020

Repetitive Transcranial Magnetic Stimulation (rTMS) Improves the Gait Disorders of Rats Under Simulated Microgravity Conditions Associated With the Regulation of Motor Cortex.

Front Physiol 2021 4;12:587515. Epub 2021 Feb 4.

Institute of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.

In previous studies, it has been proved that repetitive transcranial magnetic stimulation (rTMS) improves dyskinesia induced by conditions such as spinal cord injury, Parkinson diseases and cerebral ischemia. However, it is still unknown whether it can be used as a countermeasure for gait disorders in astronauts during space flight. In this study, we evaluated the effects of rTMS on the rat gait function under simulated microgravity (SM) conditions. Read More

View Article and Full-Text PDF
February 2021

Six degrees head-down tilt bed rest caused low-grade hemolysis: a prospective randomized clinical trial.

NPJ Microgravity 2021 Feb 15;7(1). Epub 2021 Feb 15.

Department of Medicine, Division of Physical Medicine and Rehabilitation, Ottawa Hospital Research Institute, Ottawa, ON, Canada.

This study aimed to measure hemolysis before, during and after 60 days of the ground-based spaceflight analog bed rest and the effect of a nutritional intervention through a prospective randomized clinical trial. Twenty male participants were hospitalized for 88 days comprised of 14 days of ambulatory baseline, 60 days of 6° head-down tilt bed rest and 14 days of reambulation. Ten participants each received a control diet or daily polyphenol associated with omega-3, vitamin E, and selenium supplements. Read More

View Article and Full-Text PDF
February 2021

Quantitative proteomic analysis of cortex in the depressive-like behavior of rats induced by the simulated complex space environment.

J Proteomics 2021 Apr 11;237:104144. Epub 2021 Feb 11.

School of Life Science, Beijing Institute of Technology, Beijing 100081, China.

Long-term spaceflight has always been challenging for astronauts due to the extremely complicated space environmental conditions, including microgravity, noise, confinement, and circadian rhythms disorders, which may cause adverse effects on astronauts' mental health, such as anxiety and depression. Unfortunately, so far, the underlying mechanism is not fully understood. Hence, a novel type of box and rat cage was designed and built in order to simulate complex space environment on the ground. Read More

View Article and Full-Text PDF

Exposure to hypergravity during zebrafish development alters cartilage material properties and strain distribution.

Bone Joint Res 2021 Feb;10(2):137-148

School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.

Aims: Vertebrates have adapted to life on Earth and its constant gravitational field, which exerts load on the body and influences the structure and function of tissues. While the effects of microgravity on muscle and bone homeostasis are well described, with sarcopenia and osteoporosis observed in astronauts returning from space, the effects of shorter exposures to increased gravitational fields are less well characterized. We aimed to test how hypergravity affects early cartilage and skeletal development in a zebrafish model. Read More

View Article and Full-Text PDF
February 2021

Evaluation of Cardiac Circadian Rhythm Deconditioning Induced by 5-to-60 Days of Head-Down Bed Rest.

Front Physiol 2020 13;11:612188. Epub 2021 Jan 13.

Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy.

Head-down tilt (HDT) bed rest elicits changes in cardiac circadian rhythms, generating possible adverse health outcomes such as increased arrhythmic risk. Our aim was to study the impact of HDT duration on the circadian rhythms of heart beat (RR) and ventricular repolarization (QTend) duration intervals from 24-h Holter ECG recordings acquired in 63 subjects during six different HDT bed rest campaigns of different duration (two 5-day, two 21-day, and two 60-day). Circadian rhythms of RR and QTend intervals series were evaluated by Cosinor analysis, resulting in a value of midline (MESOR), oscillation amplitude (OA) and acrophase (φ). Read More

View Article and Full-Text PDF
January 2021

Automated MRI-based quantification of posterior ocular globe flattening and recovery after long-duration spaceflight.

Eye (Lond) 2021 Jan 29. Epub 2021 Jan 29.

Cardiovascular and Vision Laboratory, Johnson Space Center, National Aeronautics and Space Administration, Houston, TX, USA.

Background/objectives: Spaceflight associated neuro-ocular syndrome (SANS), a health risk related to long-duration spaceflight, is hypothesized to result from a headward fluid shift that occurs with the loss of hydrostatic pressure gradients in weightlessness. Shifts in the vascular and cerebrospinal fluid compartments alter the mechanical forces at the posterior eye and lead to flattening of the posterior ocular globe. The goal of the present study was to develop a method to quantify globe flattening observed by magnetic resonance imaging after spaceflight. Read More

View Article and Full-Text PDF
January 2021

Microbiome dynamics during the HI-SEAS IV mission, and implications for future crewed missions beyond Earth.

Microbiome 2021 01 24;9(1):27. Epub 2021 Jan 24.

Interactive Microbiome Research, Diagnostic & Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010, Graz, Austria.

Background: Human health is closely interconnected with its microbiome. Resilient microbiomes in, on, and around the human body will be key for safe and successful long-term space travel. However, longitudinal dynamics of microbiomes inside confined built environments are still poorly understood. Read More

View Article and Full-Text PDF
January 2021

Regular exercise counteracts circadian shifts in core body temperature during long-duration bed rest.

NPJ Microgravity 2021 Jan 5;7(1). Epub 2021 Jan 5.

Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.

With NASA's plans for the human exploration of Mars, astronauts will be exposed to mission durations much longer than current spaceflight missions on the International Space Station. These mission durations will increase the risk for circadian misalignment. Exercise has gained increasing interest as a non-pharmacological aid to entrain the circadian system. Read More

View Article and Full-Text PDF
January 2021

Efficient reduction of reactive black 5 and Cr(Ⅵ) by a newly isolated bacterium of Ochrobactrum anthropi.

J Hazard Mater 2021 Mar 4;406:124641. Epub 2020 Dec 4.

School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, Hunan, China; Key Laboratory of Biometallurgy of Ministry of Education, Changsha 410083, Hunan, China. Electronic address:

It is important to obtain bacteria with the ability for reduction of dyes and Cr(Ⅵ) since dyes and Cr(Ⅵ) are often co-exist in textile wastewater. In this study, a new strain belonging to Ochrobactrum anthropi was isolated from textile wastewater, and could efficiently reduce Reactive Black 5 (RB 5) and Cr(Ⅵ). The results showed the degradation efficiency of RB 5 could achieve 100% and reduction efficiency of Cr(Ⅵ) was up to 80% within 3 days at initial RB 5 and Cr(Ⅵ) concentration of 400 mg/L and 20 mg/L. Read More

View Article and Full-Text PDF

The effects of a spaceflight analog with elevated CO on sensorimotor adaptation.

J Neurophysiol 2021 02 9;125(2):426-436. Epub 2020 Dec 9.

Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida.

Aboard the International Space Station (ISS), astronauts must adapt to altered vestibular and somatosensory inputs due to microgravity. Sensorimotor adaptation on Earth is often studied with a task that introduces visuomotor conflict. Retention of the adaptation process, known as savings, can be measured when subjects are exposed to the same adaptive task multiple times. Read More

View Article and Full-Text PDF
February 2021

A Longitudinal Epigenetic Aging and Leukocyte Analysis of Simulated Space Travel: The Mars-500 Mission.

Cell Rep 2020 Dec 25;33(10):108406. Epub 2020 Nov 25.

Division of Environmental Health Sciences, School of Public Health and Center for Computational Biology, University of California, Berkeley, Berkeley, CA 94720, USA.

Astronauts undertaking long-duration space missions may be vulnerable to unique stressors that can impact human aging. Nevertheless, few studies have examined the relationship of mission duration with DNA-methylation-based biomarkers of aging in astronauts. Using data from the six participants of the Mars-500 mission, a high-fidelity 520-day ground simulation experiment, we tested relationships of mission duration with five longitudinally measured blood DNA-methylation-based metrics: DNAmGrimAge, DNAmPhenoAge, DNA-methylation-based estimator of telomere length (DNAmTL), mitotic divisions (epigenetic mitotic clock [epiTOC2]), and pace of aging (PoA). Read More

View Article and Full-Text PDF
December 2020

Gravity and Mastoid Effusion.

Am J Med 2021 03 25;134(3):e181-e183. Epub 2020 Oct 25.

DLR-German Aerospace Center, Institute for Aerospace Medicine, Cologne, Germany.

Background: Asymptomatic mastoid effusions have recently been observed in astronauts returning from long-term spaceflight. In hospitalized patients, mastoid effusion increases the risks for bacterial otitis and mastoiditis. We reasoned that cephalad fluid shifts during strict -6° head down tilt bed rest could reproduce space-flight associated mastoid effusion and that artificial gravity may reverse the response. Read More

View Article and Full-Text PDF

Shifts in broadband power and alpha peak frequency observed during long-term isolation.

Sci Rep 2020 10 22;10(1):17987. Epub 2020 Oct 22.

Institute of Movement and Neurosciences, German Sport University, Am Sportpark Muengersdorf 6, 50933, Cologne, Germany.

Prolonged periods of social isolation and spatial confinement do not only represent an issue that needs to be faced by a few astronauts during space missions, but can affect all of us as recently shown during pandemic situations. The fundamental question, how the brain adapts to periods of sensory deprivation and re-adapts to normality, has only received little attention. Here, we use eyes closed and eyes open resting-state electroencephalographic (EEG) recordings to investigate how neural activity is altered during 120 days of isolation in a spatially confined, space-analogue environment. Read More

View Article and Full-Text PDF
October 2020

Brain connectivity and behavioral changes in a spaceflight analog environment with elevated CO.

Neuroimage 2021 01 16;225:117450. Epub 2020 Oct 16.

Department of Applied Physiology and Kinesiology, University of Florida, 1864 Stadium Rd., Gainesville, FL 32611, United States. Electronic address:

Astronauts are exposed to microgravity and elevated CO levels onboard the International Space Station. Little is known about how microgravity and elevated CO combine to affect the brain and sensorimotor performance during and after spaceflight. Here we examined changes in resting-state functional connectivity (FC) and sensorimotor behavior associated with a spaceflight analog environment. Read More

View Article and Full-Text PDF
January 2021

Plasticity of the human IgM repertoire in response to long-term spaceflight.

FASEB J 2020 Dec 13;34(12):16144-16162. Epub 2020 Oct 13.

Stress Immunity Pathogens Laboratory, EA 7300 Faculty of Medicine, Lorraine University, Vandoeuvre-lès-Nancy, France.

Immune dysregulation is among the main adverse outcomes of spaceflight. Despite the crucial role of the antibody repertoire in host protection, the effects of spaceflight on the human antibody repertoire are unknown. Consequently, using high-throughput sequencing, we examined the IgM repertoire of five cosmonauts 25 days before launch, after 64 ± 11 and 129 ± 20 days spent on the International Space Station (ISS), and at 1, 7, and 30 days after landing. Read More

View Article and Full-Text PDF
December 2020

Using Electrical Impedance Myography as a Biomarker of Muscle Deconditioning in Rats Exposed to Micro- and Partial-Gravity Analogs.

Front Physiol 2020 15;11:557796. Epub 2020 Sep 15.

Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States.

As astronauts prepare to undertake new extra-terrestrial missions, innovative diagnostic tools are needed to better assess muscle deconditioning during periods of weightlessness and partial gravity. Electrical impedance myography (EIM) has been used to detect muscle deconditioning in rodents exposed to microgravity during spaceflight or using the standard ground-based model of hindlimb unloading via tail suspension (HU). Here, we used EIM to assess muscle changes in animals exposed to two new models: hindlimb suspension using a pelvic harness (HLS) and a partial weight-bearing (PWB) model that mimics partial gravity (including Lunar and Martian gravities). Read More

View Article and Full-Text PDF
September 2020

Effects of Six Sequential Charged Particle Beams on Behavioral and Cognitive Performance in B6D2F1 Female and Male Mice.

Front Physiol 2020 28;11:959. Epub 2020 Aug 28.

Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.

The radiation environment astronauts are exposed to in deep space includes galactic cosmic radiation (GCR) with different proportions of all naturally occurring ions. To assist NASA with assessment of risk to the brain following exposure to a mixture of ions broadly representative of the GCR, we assessed the behavioral and cognitive performance of female and male C57BL/6J × DBA2/J F1 (B6D2F1) mice two months following rapidly delivered, sequential 6 beam irradiation with protons (1 GeV, LET = 0.24 keV, 50%), He ions (250 MeV/n, LET = 1. Read More

View Article and Full-Text PDF

Spaceflight induces oxidative damage to blood-brain barrier integrity in a mouse model.

FASEB J 2020 Nov 26;34(11):15516-15530. Epub 2020 Sep 26.

Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.

Many factors contribute to the health risks encountered by astronauts on missions outside Earth's atmosphere. Spaceflight-induced potential adverse neurovascular damage and late neurodegeneration are a chief concern. The goal of the present study was to characterize the effects of spaceflight on oxidative damage in the mouse brain and its impact on blood-brain barrier (BBB) integrity. Read More

View Article and Full-Text PDF
November 2020

Changes in performance and bio-mathematical model performance predictions during 45 days of sleep restriction in a simulated space mission.

Sci Rep 2020 09 24;10(1):15594. Epub 2020 Sep 24.

Human Computer Interaction Group, Human Systems Integration Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA.

Lunar habitation and exploration of space beyond low-Earth orbit will require small crews to live in isolation and confinement while maintaining a high level of performance with limited support from mission control. Astronauts only achieve approximately 6 h of sleep per night, but few studies have linked sleep deficiency in space to performance impairment. We studied crewmembers over 45 days during a simulated space mission that included 5 h of sleep opportunity on weekdays and 8 h of sleep on weekends to characterize changes in performance on the psychomotor vigilance task (PVT) and subjective fatigue ratings. Read More

View Article and Full-Text PDF
September 2020

Daily generation of a footward fluid shift attenuates ocular changes associated with head-down tilt bed rest.

J Appl Physiol (1985) 2020 11 17;129(5):1220-1231. Epub 2020 Sep 17.

Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas.

Astronauts have presented with a constellation of visual changes referred to as spaceflight-associated neuro-ocular syndrome (SANS). However, neither have early markers of microgravity-induced optic remodeling been fully identified nor have countermeasures been developed. To identify early markers of SANS, we studied 10 subjects with optical coherence tomography and ultrasonography when upright and supine and again after 24 h of 6° head-down tilt (HDT) bed rest. Read More

View Article and Full-Text PDF
November 2020

Simulated microgravity disturbs iron metabolism and distribution in humans: Lessons from dry immersion, an innovative ground-based human model.

FASEB J 2020 Nov 12;34(11):14920-14929. Epub 2020 Sep 12.

Laboratory "Movement Sport and Health Sciences" EA7470, University of Rennes/ENS Rennes, Bruz, France.

The objective of the present study was to determine the effects of dry immersion, an innovative ground-based human model of simulated microgravity and extreme physical inactivity, on iron homeostasis and distribution. Twenty young healthy men were recruited and submitted to 5 days of dry immersion (DI). Fasting blood samples and MRI were performed before and after DI exposure to assess iron status, as well as hematological responses. Read More

View Article and Full-Text PDF
November 2020

Neural Working Memory Changes During a Spaceflight Analog With Elevated Carbon Dioxide: A Pilot Study.

Front Syst Neurosci 2020 28;14:48. Epub 2020 Jul 28.

Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States.

Spaceflight missions to the International Space Station (ISS) expose astronauts to microgravity, radiation, isolation, and elevated carbon dioxide (CO), among other factors. Head down tilt bed rest (HDBR) is an Earth-based analog for spaceflight used to study body unloading, fluid shifts, and other factors unrelated to gravitational changes. While in space, astronauts need to use mental rotation strategies to facilitate their adaptation to the ISS environment. Read More

View Article and Full-Text PDF

Effect of Heavy Ion C Radiation on Lipid Constitution in the Rat Brain.

Molecules 2020 Aug 18;25(16). Epub 2020 Aug 18.

Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing 100081, China.

Heavy ions refer to charged particles with a mass greater than four (i.e., alpha particles). Read More

View Article and Full-Text PDF

Space Flight Diet-Induced Deficiency and Response to Gravity-Free Resistive Exercise.

Nutrients 2020 Aug 11;12(8). Epub 2020 Aug 11.

Exercise Physiology Program, University of Louisville, Louisville, KY 40208, USA.

Immune system dysregulation is among the many adverse effects incurred by astronauts during space flights. Omega-3 fatty acids, β-alanine, and carnosine are among the many nutrients that contribute to immune system health. For space flight, crewmembers are prescribed a diet with a macronutrient composition of 55% carbohydrate, 30% fat, and 15% protein. Read More

View Article and Full-Text PDF

Impacts of Microgravity Analogs to Spaceflight on Cerebral Autoregulation.

Front Physiol 2020 3;11:778. Epub 2020 Jul 3.

INSERM UMR 1048, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France.

It is well known that exposure to microgravity in astronauts leads to a plethora physiological responses such as headward fluid shift, body unloading, and cardiovascular deconditioning. When astronauts return to Earth, some encounter problems related to orthostatic intolerance. An impaired cerebral autoregulation (CA), which could be compromised by the effects of microgravity, has been proposed as one of the mechanisms responsible for orthostatic intolerance. Read More

View Article and Full-Text PDF

Radioprotective effects of induced astronaut torpor and advanced propulsion systems during deep space travel.

Life Sci Space Res (Amst) 2020 Aug 10;26:105-113. Epub 2020 Jun 10.

Université de Lyon. CNRS UMR5208 Institut Camille Jordan. Villeurbanne, France & Inria Grenoble, France.

Background: Human metabolic suppression is not a new concept, with 1950s scientific literature and movies demonstrating its potential use for deep space travel (Hock, 1960). An artificially induced state of metabolic suppression in the form of torpor would improve the amount of supplies required and therefore lessen weight and fuel required for missions to Mars and beyond (Choukèr et al., 2019). Read More

View Article and Full-Text PDF

Relationship Between Acute Physical Fatigue and Cognitive Function During Orthostatic Challenge in Men and Women: A Neuroergonomics Investigation.

Hum Factors 2020 Jul 17:18720820936794. Epub 2020 Jul 17.

936794 Texas A&M University, College Station, USA.

Background: Postflight orthostatic challenge (OC), resulting from blood pooling in lower extremities, is a major health concern among astronauts that fly long-duration missions. Additionally, astronauts undergo physical demanding tasks resulting in acute fatigue, which can affect performance. However, the effects of concurrent OC and acute physical fatigue on performance have not been adequately investigated. Read More

View Article and Full-Text PDF

[Collagen Peptides Improve Lymphocyte Distribution in Peripheral Blood and T Lymphocyte Proliferation in Spleen of Mice under the Condition of Simulated Weightlessness].

Zhongguo Shi Yan Xue Ye Xue Za Zhi 2020 Jun;28(3):1001-1005

Center for Special Medicine and Experimental Research, Medical Center of PLA Strategic Support Force, Beijing 100101,

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. Read More

View Article and Full-Text PDF