68 results match your criteria: "National Aeronautics and Space Administration-Johnson Space Center[Affiliation]"

Chorion trophoblasts (CTCs) and immune cell-enriched decidua (DECs) comprise the maternal-fetal membrane interface called the chorio-decidual interface (CDi) which constantly gets exposed to maternal stressors without leading to labor activation. This study explored how CTCs act as a barrier at CDi. The roles of human leukocyte antigen (HLA)-G and progesterone receptor membrane component 2 (PGRMC2) in mediating immune homeostasis were also investigated.

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Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (D) flux are presented. The measurements are based on 21×10^{6} D nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021.

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Individuals in isolated and extreme environments can experience debilitating side-effects including significant decreases in fat-free mass (FFM) from disuse and inadequate nutrition. The objective of this study was to determine the strengths and weaknesses of three-dimensional optical (3DO) imaging for monitoring body composition in either simulated or actual remote environments. Thirty healthy adults (ASTRO, male = 15) and twenty-two Antarctic Expeditioners (ABCS, male = 18) were assessed for body composition.

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Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.

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We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.

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We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.

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The extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: O-rich (associated with refractory inclusions) and O-poor (associated with chondrules). Both the O-rich and O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward.

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Article Synopsis
  • About 70% of astronauts on long space missions develop optic disc edema, a sign of spaceflight-associated neuro-ocular syndrome, but the cause of variability among individuals is still unclear.
  • The study aims to identify risk factors for this condition by examining preflight ocular characteristics, demographics, and body metrics of 31 crew members during their time at NASA and the ISS.
  • The analysis focuses on various ocular measurements and demographic data to evaluate their relationship with increases in retinal thickness, an indicator of optic disc edema during spaceflight.
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Properties of Daily Helium Fluxes.

Phys Rev Lett

June 2022

INFN TIFPA, 38123 Povo, Trento, Italy.

We present the precision measurement of 2824 daily helium fluxes in cosmic rays from May 20, 2011 to October 29, 2019 in the rigidity interval from 1.71 to 100 GV based on 7.6×10^{8} helium nuclei collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station.

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Importance: Countermeasures that reverse the headward fluid shift experienced in weightlessness have the potential to mitigate spaceflight-associated neuro-ocular syndrome. This study investigated whether use of the countermeasure lower-body negative pressure during spaceflight was associated with changes in ocular structure.

Objective: To determine whether changes to the optic nerve head and retina during spaceflight can be mitigated by brief in-flight application of 25-mm Hg lower-body negative pressure.

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Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples.

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Motor adaptations to the microgravity environment during spaceflight allow astronauts to perform adequately in this unique environment. Upon return to Earth, this adaptation is no longer appropriate and can be disruptive for mission critical tasks. Here, we measured if metrics derived from MRI scans collected from astronauts can predict motor performance post-flight.

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We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales.

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Article Synopsis
  • This study analyzes the cosmic rays of sodium (Na) and aluminum (Al) within a rigidity range of 2.15 GV to 3.0 TV, using data from the Alpha Magnetic Spectrometer on the ISS.
  • The findings indicate that Na and Al belong to a unique cosmic ray group alongside nitrogen (N), showing similar flux behaviors.
  • The research establishes that both Na and Al fluxes can be explained by a combination of primary and secondary cosmic ray components, with the primary component becoming more significant at higher rigidities.
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Background: Immobilization and related oxidative stress are associated with bone loss. Antioxidants like polyphenols, omega-3 fatty acids, vitamins, and micronutrients may mitigate these negative effects on bone metabolism through scavenging of free radicals.

Objectives: We hypothesized that antioxidant supplementation during 60 days of 6° head-down tilt bed rest (HDBR) would reduce bone resorption and increase bone formation compared to nonsupplemented controls.

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Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.

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We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.

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We report the observation of new properties of primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.

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Importance: During long-duration spaceflights, nearly all astronauts exhibit some change in ocular structure within the spectrum of spaceflight-associated neuro-ocular syndrome.

Objective: To quantitatively determine in a prospective study whether changes in ocular structures hypothesized to be associated with the development of spaceflight-associated neuro-ocular syndrome occur during 6-month missions on board the International Space Station (ISS).

Design, Setting, And Participants: The Ocular Health ISS Study of astronauts is a longitudinal prospective cohort study that uses objective quantitative imaging modalities.

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Article Synopsis
  • - The Alpha Magnetic Spectrometer (AMS) conducted precision measurements of helium isotopes (^3He and ^4He) on the International Space Station, collecting data from 100 million ^4He and 18 million ^3He nuclei over six years from 2011 to 2017.
  • - The study found that the fluxes of both helium isotopes varied similarly over time, but the amount of variation decreased as the rigidity (energy per unit charge) increased.
  • - For the first time, researchers measured the rigidity dependence of the ^3He/^4He flux ratio, showing notable long-term changes below 4 GV but stable characteristics and a specific power law relationship above that threshold, aligning with other spectral indices in
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As the international space community plans for manned missions to Mars, spaceflight-associated immune dysregulation has been identified as a potential risk to the health and safety of the flight crew. There is a need to determine whether salivary antimicrobial proteins, which act as a first line of innate immune defense against multiple pathogens, are altered in response to long-duration (>6 mo) missions. We collected 7 consecutive days of whole and sublingual saliva samples from eight International Space Station (ISS) crewmembers and seven ground-based control subjects at nine mission time points, ~180 and ~60 days before launch (L-180/L-60), on orbit at flight days ~10 and ~90 (FD10/FD90) and ~1 day before return (R-1), and at R+0, R+18, R+33, and R+66 days after returning to Earth.

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