Results for “Selectable marker” — Page 2

NASA NTRS2004

Development and Performance of the Oxygen Sensor in the CSA-CP Aboard the International Space Station

A combustion products analyzer (CPA) was built for use on Shuttle in response to several thermodegradation incidents that had occurred during early flights. The CPA contained sensors that measured carbon monoxide, hydrogen chloride, hydrogen cyanide, and hydrogen fluoride. These marker compounds, monitored by the CPA, were selected based upon the likely products to be released in a spacecraft fire. When the Toxicology Laboratory group at Johnson Space Center (JSC) began to assess the air quality monitoring needs for the International Space Station (ISS), the CPA was the starting point for design of an instrument to monitor the atmosphere following a thermodegradation event. The final product was significantly different from the CPA and was named the compound specific analyzer-combustion products (CSA-CP). The major change from the CPA that will be the focus of this paper was the replacement of an unreliable hydrogen fluoride (HF) sensor with an oxygen sensor. A reliable HF sensor was not commercially available, but as the toxicology group reviewed the overall monitoring strategy for ISS, it appeared that a portable oxygen sensor to backup the major constituent analyzer was needed. Therefore, an oxygen sensor replaced the HF sensor in the new instrument. This paper will describe the development, deployment, and performance of the CSA-CP oxygen sensor on both Shuttle and ISS. Also, data for CSA-CP oxygen sensor accuracy at nominal and reduced pressures will be presented.

Limero, Thomas↗

NASA NTRS1999

IGF-1 induces skeletal myocyte hypertrophy through calcineurin in association with GATA-2 and NF-ATc1

Localized synthesis of insulin-like growth factors (IGFs) has been broadly implicated in skeletal muscle growth, hypertrophy and regeneration. Virally delivered IGF-1 genes induce local skeletal muscle hypertrophy and attenuate age-related skeletal muscle atrophy, restoring and improving muscle mass and strength in mice. Here we show that the molecular pathways underlying the hypertrophic action of IGF-1 in skeletal muscle are similar to those responsible for cardiac hypertrophy. Transfected IGF-1 gene expression in postmitotic skeletal myocytes activates calcineurin-mediated calcium signalling by inducing calcineurin transcripts and nuclear localization of calcineurin protein. Expression of activated calcineurin mimics the effects of IGF-1, whereas expression of a dominant-negative calcineurin mutant or addition of cyclosporin, a calcineurin inhibitor, represses myocyte differentiation and hypertrophy. Either IGF-1 or activated calcineurin induces expression of the transcription factor GATA-2, which accumulates in a subset of myocyte nuclei, where it associates with calcineurin and a specific dephosphorylated isoform of the transcription factor NF-ATc1. Thus, IGF-1 induces calcineurin-mediated signalling and activation of GATA-2, a marker of skeletal muscle hypertrophy, which cooperates with selected NF-ATc isoforms to activate gene expression programs.

Non-NASA Center↗

NASA NTRS1986

Analysis of growth patterns during gravitropic curvature in roots of Zea mays by use of a computer-based video digitizer

A computer-based video digitizer system is described which allows automated tracking of markers placed on a plant surface. The system uses customized software to calculate relative growth rates at selected positions along the plant surface and to determine rates of gravitropic curvature based on the changing pattern of distribution of the surface markers. The system was used to study the time course of gravitropic curvature and changes in relative growth rate along the upper and lower surface of horizontally-oriented roots of maize (Zea mays L.). The growing region of the root was found to extend from about 1 mm behind the tip to approximately 6 mm behind the tip. In vertically-oriented roots the relative growth rate was maximal at about 2.5 mm behind the tip and declined smoothly on either side of the maximum. Curvature was initiated approximately 30 min after horizontal orientation with maximal (50 degrees) curvature being attained in 3 h. Analysis of surface extension patterns during the response indicated that curvature results from a reduction in growth rate along both the upper and lower surfaces with stronger reduction along the lower surface.

NASA Discipline Plant Biology↗

NASA NTRS2007

The Artificial Gravity Bed Rest Pilot Project: Effects on Knee Extensor and Plantar Flexor Muscle Groups

The goal of this project was to examine the effects of artificial gravity (2.5 g) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) control (C) group (N=7); and 2) an AG group (N=8), which was exposed to 21 days of bed-rest plus daily 1 hr exposures to AG (2.5 g). This particular experiment was part of an integrated AG Pilot Project sponsored by NASA/Johnson Space Center. The in vivo torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre and post treatment. Also, pre- and post treatment biopsy samples were obtained from both the vastus lateralis and soleus muscles and were used, in part, for a series of analyses on gene expression (mRNA abundance) of key factors implicated in the anabolic versus catabolic state of the muscle. Post/Pre toque-velocity determinations revealed greater decrements in knee extensor performance in the C versus AG group (P less than 0.04). The plantar flexor muscle group of the AG subjects actually demonstrated a net gain in torque-velocity relationship; whereas, in the C group the overall post/pre responses declined (AG vs C; P less than 0.001). Measurements of muscle fiber cross-sectional area (for both muscles) demonstrated a loss of approx. 20% in the C group while no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity (IGF-1, IGF-1 BP4, mechano growth factor, total RNA, and pro-collagen 3a) were higher in the AG group, whereas catabolic markers (myostatin and atrogen) were elevated in the C group. Importantly, these patterns were seen in both muscles. Based on these observations we conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading states. These findings also warrant further studies since it is likely that other robust paradigms of AG that employ various exercise strategies may be more effective in counteracting long duration unloading states as anticipated on the platforms of the Moon and Mars.

Caiozzo, V. J.↗

NASA NTRS2017

The Integrated Impact of Diet On Human Immune Response, the Gut Microbiota, and Nutritional Status During Adaptation to a Spaceflight Analog

Spaceflight impacts human physiology, including well documented immune system dysregulation. Diet, immune function, and the microbiome are interlinked, but diet is the only one of these factors that we have the ability to easily, and significantly, alter on Earth or during flight. As we understand dietary impacts on physiology more thoroughly, we may then improve the spaceflight diet to improve crew health and potentially reduce flight-associated physiological alterations. It is expected that increasing the consumption of fruits and vegetables and bioactive compounds (e.g.,omega-3 fatty acids, lycopene, flavonoids) and therefore enhancing overall nutritional intake from the nominal shelf-stable, fully-processed space food system could serve as a countermeasure to improve human immunological profiles, the taxonomic profile of the gut microbiota, and nutritional status, especially where currently dysregulated during spaceflight. This interdisciplinary study will determine the effect of the current shelf-stable spaceflight diet compared to an "enhanced" shelf-stable spaceflight diet (25% more foods rich in omega-3 fatty acids, lycopene, flavonoids, fruits, and vegetables). The NASA Human Exploration Research Analog (HERA) 2017 missions, consisting of closed chamber confinement, realistic mission simulation, in a high-fidelity mock space vehicle, will serve as a platform to replicate mission stressors and the dysregulated physiology observed in astronauts. Biosampling of crew members will occur at selected intervals, with complete dietary tracking. Outcome measures will include immune markers (e.g., peripheral leukocyte distribution, inflammatory cytokine profiles, T cell function), the taxonomic and metatranscriptomic profile of the gut microbiome, and nutritional status biomarkers and metabolites. Data collection will also include complete dietary tracking. Statistical evaluations will determine physiological and biochemical shifts in relation to nutrient in take and study phase. Beneficial improvements will provide evidence of the impact of diet on crew health and adaptation to this spaceflight analog, and will aid in the design and development of more-efficient targeted dietary interventions.

Douglas, G. L.↗

NASA NTRSDate not supplied

Hazards of Lunar Surface Exploration: Determining the Immunogenicity/Allergenicity of Lunar Dust

There are multiple Apollo program reports of lunar dust (LD) exposure leading to significant upper respiratory symptoms in select crewmembers. Possible mechanisms include particulate irritation, oxidization and release of noxious gas, or legitimate adaptive immune-mediated response. Although sterile non-protein matter would not be expected to be an allergen, one Apollo flight surgeon reported increasing symptoms upon repeated exposure, with associated eosinophilia indicative of allergy (*Acta Astronautica. 2008 63 (7–10): 980–987). Many ISS crews display a pattern of persistent immune system dysregulation and latent virus reactivation (NPJ Microgravity. 2015 Sep 3; 1:15013; NPJ Microgravity. 2017 Apr 12; 3:11). Some ISS crews manifest atypical respiratory and/or dermatitis symptoms which could have an allergic pathogenesis (J Allergy Clin. Immunol. Pract. 2016 Jul-Aug; 4(4):759-762.e8). It is logical to anticipate crew immune dysregulation would worsen during prolonged deep space missions. Planetary surface hazards will only complicate crew health risks. This study hypothesizes that LD exposure can alter susceptible individuals’ immune responses such that repeated exposure will elicit an IgE mediated allergic response either to the LD itself or concomitant antigen exposure during spaceflight. This will adversely increase clinical and operational impacts for long-duration lunar astronauts and affect countermeasure requirements for surface vehicles. Specific aims for this study are (1) Does in vitro LD exposure result in increased histamine from human peripheral blood basophils? (2) Can LD impact the capacity of CD4+ helper and/or CD19+ B-cell mediated IgE production? To address these questions, a set of in-vitro cell culture experiments will be employed (short and long term) using human peripheral blood mononuclear cells (PBMC) and basophils from both atopic and non-atopic individuals, as well as established human basophil and mast cell lines. Cells will be co-cultured with cellular mitogens, common recall antigens (tetanus, Der p1), nickel (as a possible allergenic component of LD), with or without graded amounts of LD, to study whether LD exposure for varying time intervals will alter the generation of selective immune responses associated with clinical allergic reactions. Measured outputs include supernatant-derived IgE, tryptase, histamine and selected cytokine levels. Cellular activation will be monitored by assessing activation markers via flow cytometry. EM/x-ray analysis will be used to determine cellular interactions with dust particles. The minimal amount of LD (Apollo 14 dust) and controls/simulants have been requested. This study, originally planned as an FY20/21 activity, was delayed due to the COVID pandemic. It is now scheduled to be performed during FY22.

Brian Crucian↗

NASA NTRSDate not supplied

Hazards of Lunar Surface Exploration: Determining the Immunogenicity/Allergenicity of Lunar Dust

Although infrequent, there have been Apollo program reports of lunar dust (LD) exposure leading to notable upper respiratory symptoms in select crewmembers. Possible mechanisms include particulate irritation, oxidization and release of noxious gas, or legitimate adaptive immune-mediated response. Although sterile non-protein matter would not be expected to be an allergen, one Apollo flight surgeon reported increasing symptoms upon repeated exposure with associated eosinophilia, indicative of allergy (*Acta Astronautica. 2008 63 (7–10): 980–987). Many ISS crews display a pattern of persistent immune system dysregulation and latent virus reactivation (NPJ Microgravity. 2015 Sep 3; 1:15013; NPJ Microgravity. 2017 Apr 12; 3:11). Some ISS crews manifest atypical respiratory and/or dermatitis symptoms which could have an allergic pathogenesis (J Allergy Clin. Immunol. Pract. 2016 Jul-Aug; 4(4):759-762.e8). It is logical to anticipate crew immune dysregulation would worsen during prolonged deep space missions. Planetary surface hazards will only complicate crew health risks. This study with investigate if LD exposure will elicit an IgE mediated allergic response either to the LD itself or concomitant antigen exposure during spaceflight. Allergic reactivity could adversely increase clinical and operational impacts for long-duration lunar astronauts and affect countermeasure requirements for surface vehicles. Specific aims for this study are to answer two questions: (1) Does in vitro LD exposure result in increased histamine from human peripheral blood basophils? (2) Can LD impact the capacity of CD4+ T helper and/or CD19+ B-cell mediated IgE production? To address these questions, after the proposal and selection by NASA, our laboratory has separately requested and been approved for receipt of actual LD samples from the Apollo 16 mission. These samples will be used during the study to complete the proposed set of in vitro cell culture experiments (short and long term), using human peripheral blood mononuclear cells (PBMC) and basophils from both atopic and non-atopic individuals. Cells will be co-cultured with cellular mitogens, common recall antigens (Der p1), fine ground silica quartz (as a possible allergenic component of LD), or LD, to study whether LD exposure for varying time intervals will alter the generation of selective immune responses associated with clinical allergic reactions. Measured outputs include supernatant-derived IgE, tryptase, histamine, and selected cytokine levels. Cellular activation will be monitored by assessing activation markers via flow cytometry. EM/x-ray analysis will be used to determine cellular interactions with dust particles. A series of validation experiments was initiated in FY22 once the delivery of LD was received. Based on initial experimental findings, we are optimizing the culture conditions, LD concentrations, and refining our other protocol stimuli.

Audrie A. Colorado↗

NASA NTRSDate not supplied

Hazards of Lunar Surface Exploration: Determining the Immunogenicity/Allergenicity of Lunar Dust

Although infrequent, there have been Apollo program reports of lunar dust (LD) exposure leading to notable upper respiratory symptoms in select crewmembers. Possible mechanisms include particulate irritation, oxidization and release of noxious gas, or legitimate adaptive immune-mediated response. Although sterile non-protein matter would not be expected to be an allergen, one Apollo flight surgeon reported increasing symptoms upon repeated exposure with associated eosinophilia, indicative of allergy (*Acta Astronautica. 2008 63 (7–10): 980–987). Many ISS crews display a pattern of persistent immune system dysregulation and latent virus reactivation (NPJ Microgravity. 2015 Sep 3; 1:15013; NPJ Microgravity. 2017 Apr 12; 3:11). Some ISS crews manifest atypical respiratory and/or dermatitis symptoms which could have an allergic pathogenesis (J Allergy Clin. Immunol. Pract. 2016 Jul-Aug; 4(4):759-762.e8). It is logical to anticipate crew immune dysregulation would worsen during prolonged deep space missions. Planetary surface hazards will only complicate crew health risks. This study with investigate if LD exposure will elicit an IgE mediated allergic response either to the LD itself or concomitant antigen exposure during spaceflight. Allergic reactivity could adversely increase clinical and operational impacts for long-duration lunar astronauts and affect countermeasure requirements for surface vehicles. Specific aims for this study are to answer two questions: (1) Does in vitro LD exposure result in increased histamine from human peripheral blood basophils? (2) Can LD impact the capacity of CD4+ T helper and/or CD19+ B-cell mediated IgE production? To address these questions, after the proposal and selection by NASA, our laboratory has separately requested and been approved for receipt of actual LD samples from the Apollo 16 mission. These samples will be used during the study to complete the proposed set of in vitro cell culture experiments (short and long term), using human peripheral blood mononuclear cells (PBMC) and basophils from both atopic and non-atopic individuals. Cells will be co-cultured with cellular mitogens, common recall antigens (Der p1), fine ground silica quartz (as a possible allergenic component of LD), or LD, to study whether LD exposure for varying time intervals will alter the generation of selective immune responses associated with clinical allergic reactions. Measured outputs include supernatant-derived IgE, tryptase, histamine, and selected cytokine levels. Cellular activation will be monitored by assessing activation markers via flow cytometry. EM/x-ray analysis will be used to determine cellular interactions with dust particles. A series of validation experiments was initiated in FY22 once the delivery of LD was received. Based on initial experimental findings, we are optimizing the culture conditions, LD concentrations, and refining our other protocol stimuli.

immunology↗

NASA NTRS2013

Spacecraft 3D Augmented Reality Mobile App

The Spacecraft 3D application allows users to learn about and interact with iconic NASA missions in a new and immersive way using common mobile devices. Using Augmented Reality (AR) techniques to project 3D renditions of the mission spacecraft into real-world surroundings, users can interact with and learn about Curiosity, GRAIL, Cassini, and Voyager. Additional updates on future missions, animations, and information will be ongoing. Using a printed AR Target and camera on a mobile device, users can get up close with these robotic explorers, see how some move, and learn about these engineering feats, which are used to expand knowledge and understanding about space. The software receives input from the mobile device's camera to recognize the presence of an AR marker in the camera's field of view. It then displays a 3D rendition of the selected spacecraft in the user's physical surroundings, on the mobile device's screen, while it tracks the device's movement in relation to the physical position of the spacecraft's 3D image on the AR marker.

Hussey, Kevin J.↗

NASA NTRS1995

A record of all marker bands found in the upper rivet rows of 2 adjacent bays from a fuselage lap splice joint

A full scale fuselage test article was subjected to 60,000 load cycles (pressurizations) to study the effect of widespread fatigue damage in fuselage structures. Every 10,000 cycles coded marker block loading sequences were used to mark the fracture surfaces of the fatigue cracks propagating within the panel. The loading sequences consisted of series of underloads combined with a series of full pressurizations. The combination of loads and underloads marked the fracture surfaces with marker bands that could later be used to reconstruct the fatigue crack growth history of selected regions within the test article. Thirty rivet holes comprising the upper rivet rows from two adjacent bays (bays #3 and #4) from a fuselage lap splice joint were examined for the purpose of this study. Optical and scanning electron microscopy (SEM) were used to locate the marker bands.

Willard, Scott A.↗

NASA NTRS1985

Electrophoresis technology

A new high resolution apparatus designed for space was built as a laboratory prototype. Using a moving wall with a low zeta potential coating, the major sources of flow distortion for an electrophoretic sample stream are removed. Highly resolved fractions, however, will only be produced in space because of the sensitivity of this chamber to buoyancy-induced convection in the laboratory. The second and third flights of the McDonnell Douglas Astronautics Corporation continuous flow electrophoresis system carried samples developed at MSFC intended to evaluate the broad capabilities of free flow electrophoresis in a reduced gravity environment. Biological model materials, hemoglobin and polystyrene latex microspheres, were selected because of their past use as electrophoresis standards and as visible markers for fluid flow due to electroosmosis, spacecraft acceleration or other factors. The dependence of the separation resolution on the properties of the sample and its suspension solution was assessed.

Snyder, R. S.↗

NASA NTRS2014

Salt Tolerance and Polyphyly in the Cyanobacterium Chroococcidiopsis (Pleurocapsales)1

Chroococcidiopsis Geitler (Geitler 1933) is a genus of cyanobacteria containing desiccation and radiation resistant species. Members of the genus live in habitats ranging from hot and cold deserts to fresh and saltwater environments. Morphology and cell division pattern have historically been used to define the genus. To better understand the genetic and phenotypic diversity of the genus, 15 species were selected that had been previously isolated from different locations, including salt and freshwater environments. Four markers were sequenced from these 15 species, the 16S rRNA, rbcL, desC1 and gltX genes. Phylogenetic trees were generated which identified two distinct clades, a salt-tolerant clade and a freshwater clade. This study demonstrates that the genus is polyphyletic based on saltwater and freshwater phenotypes. To understand the resistance to salt in more details, species were grown on a range of sea salt concentrations which demonstrated that the freshwater species were salt-intolerant whilst the saltwater species required salt for growth. This study shows an increased resolution of the phylogeny of Chroococcidiopsis and provides further evidence that the genus is polyphyletic and should be reclassified to improve clarity in the literature.

Genus↗

NASA NTRS1992

The value of the 4-day headdown bedrest model for screening countermeasures

In order to evaluate the benefits of periodic exposure to the +G(z) vector as a countermeasure to the physiological responses to minus 6 degree head down bedrest (HDT), we considered a two-tiered approach: (a) to use 4 days HDT as a quick and inexpensive means of screening countermeasures, (b) to use a 60 day HDT to validate the most promising candidates. The approach and results of a 4 day study are described here. Methods: Nine males were admitted to our Human Research Facility for one ambulatory control day followed by 4 days HDT and were released on the next day after completion of a peak oxygen consumption test (VO(sub 2 peak)). A battery of tests was selected and standardized to evaluate the known early effects of HDT on plasma volume, early bone markers, orthostatic tolerance, physical performance, and fluid and electrolytes and their hormone regulation. Fluid sodium (Na) and potassium (K) intake and output in the urine were monitored throughout. Plasma volume was determined with a modified Evans Blue method and orthostatic tolerance with a 60 degree head-up tilt test for 30 minutes - both of which were determined on the ambulatory control day and on day 4 of HDT. Immediately after completion of the tilt test subjects were returned to the minus 6 degree position until the next morning when a VO(sub 2 peak) (horizontal ergometer) was done. This was compared to a similar control test determined on 2 separate occasions before subject admission. Results: Four hours after going HDT produced significant decreases (p less than 0.05) in the circulating concentration of fluid and electrolyte regulating hormones. Plasma volume, orthostatic tolerance and VO(sub 2 peak) changed significantly after 4 days HDT. There was also the expected natriuresis on day 1 of HDT but no significant diuresis. The consistency of the pre-bedrest VO(sub 2 peak) tilt tests and plasma volumes was remarkable. Conclusions: The 4 day HDT model seems highly promising for screening a variety of countermeasures alone and in combination before validating their benefits in extended bedrest or flight experiments.

Vernikos, J.↗

NASA NTRSDate not supplied

Next Generation Exercise Device (NGED): Advancing Exercise Capabilities for Future Space Missions Through Biomechanical Modeling

BACKGROUND As space exploration extends to long-duration missions on the Moon and Mars, maintaining astronaut health and fitness becomes increasingly critical. The Next Generation Exercise Device (NGED), developed and tested by the HumanWorks Lab in NASA Johnson Space Center's (JSC) Software, Robotics, and Simulation Division, aims to address this challenge through innovative approaches. This study presents the development and evaluation of an NGED system, focusing on its adaptability to various mission scenarios, including prospective use in a Lunar Pressurized Rover (LPR). Central to this project is the application of biomechanical modeling to optimize exercise efficacy and safety in microgravity and partial gravity environments. The project is a collaborative effort with the Human Health and Performance group at Johnson Space Center, ensuring a comprehensive approach to astronaut well-being that integrates biomechanical principles with practical exercise solutions. The NGED represents the next generation of exercise capabilities for missions in space, on the Moon and Mars, with a specific focus on applications such as the LPR. METHODS AND RESULTS Data collection for NGED development was conducted with two motor-driven Beyond Power Voltra I [1] systems and a custom test structure to allow placement of the cable-based devices on the ground, at shoulder height, and overhead. The collection was performed in JSC’s Prototype Immersive Technology (PIT) Lab, utilizing an OptiTrack motion capture system and AMTI force platform, to enable detailed biomechanical analysis via OpenSim [2,3]. Motion capture data were collected for three subjects representing different body types and statures. The marker set used was an enhanced version of the full-body Plug-in Gait marker set [4], with additional markers strategically placed for the primary objective of informing exercise volume requirements. Subjects performed a series of 17 exercises, carefully selected to engage various muscle groups, including novel spaceflight exercises such as skiing (ergometer style), lateral pulldowns, wood chops, triceps extensions, and flies, with load variations ranging from 10 to 90 pounds to maintain kinematic form. This comprehensive approach allowed for a thorough evaluation of the NGED's performance across a wide range of motions and loads. The biomechanical modeling and analysis were conducted using a modified OpenSim Full Body Rajagopal Model [4,5] and also scaled to the maximum and minimum anthropometry provided in NASA-STD-3001 [6]. Volumetric convex hulls were generated based on model marker trajectories and aggregated into geometric assemblies. These can be placed in models of vehicle designs to assess fit to protect for exercise as well as to adapt NGED exercise to fit available space. Preliminary findings from the collection indicate that the NGED prototype demonstrates significant adaptability across varying user anthropometrics and exercise types. The device showed consistent performance in load-bearing exercises, with subjects able to perform exercises effectively while maintaining proper biomechanical form. CONCLUSION NGED represents a forward-looking advancement in exercise capabilities for future space missions. In the future, this system can be used to capture valuable metrics (e.g., isometric mid-thigh pull for force output measurements, assessments of postural muscle strength, overall isometric strength). Its versatility in accommodating various exercises and user physiques, coupled with the ability to provide targeted biomechanical loading, makes it a promising approach for maintaining astronaut health during long-duration missions to the Moon and Mars. Future work will focus on refining the NGED based on initial biomechanical findings, leveraging the detailed insights provided by motion capture and analysis techniques. Particular emphasis will be placed on optimizing its use within the confined spaces of a LPR and other space habitats. This work contributes significantly to NASA's goals of supporting human health and performance in deep space exploration, paving the way for sustainable long-term presence beyond Low Earth Orbit through advanced, biomechanically-informed exercise solutions.

C Wang↗

NASA NTRS2019

Carbon Nanostructures in Biological Sensors for Space and Terrestrial Applications

Biosensing devices comprised of carbon nanotubes and nanofibers have been developed for astronaut crew point-of-care. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report two studies using carbon nanotube and carbon nanofiber electrodes for biomedical applications. First, a 3x3 electrode device, with each electrode containing 40,000 carbon nanofiber nanoelectrodes was fabricated on silicon using traditional microfabrication processing. The device was demonstrated as a multiplexed immunosensor for simultaneous, label-free detection of cardiac troponin-I, C-reactive protein and myoglobin. Antibodies specific to cardiac troponin-I, C-reactive protein and myoglobin were covalently bound to the CNF surface and were characterized using electrochemical impedance spectroscopy and differential pulse voltammetry. Each step of the modification process resulted in changes in resistance to charge transfer due to the changes at the electrode surface upon antibody immobilization and binding to the specific cardiac protein. The real-time label free detection of the three cardiac markers from pure components and mixtures was demonstrated with high sensitivity, down to 0.2 ng/mL, and good selectivity. Detection in human blood serum did not present false positives from non-specific protein adsorption. More recently, this detection scheme has been applied to inkjet printed carbon nanotube electrodes on Kapton and paper. Printed devices have several unique advantages including simple and inexpensive fabrication. The results demonstrate that these sensors can serve a miniaturized, low cost device for detection of proteins in complex mixtures making this platform a good candidate for early stage diagnosis of myocardial infarction. Future inkjet printed devices can be fabricated have the added advantage in their suitability to be manufactured in an in-space, microgravity environment.

carbon nanotubes↗

NASA NTRS2019

Carbon Nanomaterials for Biosensing Applications

Biosensing devices comprised of carbon nanotubes and nanofibers have been developed for astronaut crew point-of-care. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report two studies using carbon nanotube and carbon nanofiber electrodes for biomedical applications. First, a 3x3 electrode device, with each electrode containing 40,000 carbon nanofiber nanoelectrodes was fabricated on silicon using traditional microfabrication processing. The device was demonstrated as a multiplexed immunosensor for simultaneous, label-free detection of cardiac troponin-I, C-reactive protein and myoglobin. Antibodies specific to cardiac troponin-I, C-reactive protein and myoglobin were covalently bound to the CNF surface and were characterized using electrochemical impedance spectroscopy and differential pulse voltammetry. Each step of the modification process resulted in changes in resistance to charge transfer due to the changes at the electrode surface upon antibody immobilization and binding to the specific cardiac protein. The real-time label free detection of the three cardiac markers from pure components and mixtures was demonstrated with high sensitivity, down to 0.2 ng/mL, and good selectivity. Detection in human blood serum did not present false positives from non-specific protein adsorption. More recently, this detection scheme has been applied to inkjet printed carbon nanotube electrodes on Kapton and paper. Printed devices have several unique advantages including simple and inexpensive fabrication. The results demonstrate that these sensors can serve a miniaturized, low cost device for detection of proteins in complex mixtures making this platform a good candidate for early stage diagnosis of myocardial infarction. Future inkjet printed devices can be fabricated have the added advantage in their suitability to be manufactured in an in-space, microgravity environment.

carbon nanotubes↗

NASA NTRS1984

Constraints on future observing plans

Scheduling considerations in the deployment of transportable laser ranging systems (TLRS) in 1985 are discussed. The new TLRS units will be field tested in North America and Europe first before being sent to remote Mediterranean and South American sites. Six weeks' residence will be required for 600 hr of measurements at each site, although a second crew could bring the necessary time down to four weeks. The surveys are set for periods of the year with the greatest incidence of clear skies. Twelve sites have been selected in the Mediterranean area, although no weather data have been acquired. Site selections are constrained by the need for accessible roads, telephones, and the stability of the terrain. Details of the marker monument layouts are provided.

Coates, R. J.↗

NASA NTRS2018

The Integrated Impact of Diet on Human Immune Response, the Gut Microbiota, and Nutritional Status During Adaptation to a Spaceflight Analog

Spaceflight impacts human physiology, including well documented immune system dysregulation. Diet, immune function, and the microbiome are interlinked, but diet is the only one of these factors that we have the ability to easily, and significantly, alter on Earth or during flight. As we understand dietary impacts on physiology more thoroughly, we may then improve the spaceflight diet to improve crew health and potentially reduce spaceflight-associated physiological alterations. It is expected that increasing the consumption of fruits and vegetables and bioactive compounds (e.g., omega-3 fatty acids, lycopene, flavonoids) and therefore enhancing overall nutritional intake from the nominal shelf-stable, fully-processed space food system could serve as a countermeasure to improve human immunological profiles, the taxonomic profile of the gut microbiota, and nutritional status, especially where currently dysregulated during spaceflight. This interdisciplinary study will determine the effect of the current shelf-stable spaceflight diet compared to an "enhanced" shelf-stable spaceflight diet (25% more foods rich in omega-3 fatty acids, lycopene, flavonoids, and more fruits, and vegetables in general). The NASA Human Exploration Research Analog (HERA) 2017 missions, consisting of four 45-day missions with closed chamber confinement and realistic mission simulation in a high-fidelity mock space vehicle, will serve as a platform to replicate mission stressors and the effects on crew biochemistry, immunology, and the gut microbiome. Bio sampling of crewmembers is scheduled for selected intervals pre- and in-mission. Data collection also includes dietary intake recording. Outcome measures will include immune markers (e.g., peripheral leukocyte distribution, inflammatory cytokine profiles, T cell function), the taxonomic and metatranscriptomic profile of the gut microbiome, and nutritional status biomarkers and metabolites. Statistical evaluations will determine physiological and biochemical shifts in relation to nutrient intake and study phase. To date, sample collection has been completed for 2 crewmembers from the first mission, aka Campaign 4 Mission 1. Mission 2 was terminated after 22 days due to effects of Hurricane Harvey, and sample collection was not completed. Sample collection will continue for Campaign 4 Mission 3 and 4 prior to comprehensive sample analysis. Beneficial improvements will provide evidence of the impact of diet on crew health and adaptation to this spaceflight analog, and will aid in the design and development of more-efficient targeted dietary interventions for exploration missions.

Douglas, G. L.↗