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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2008

Space Adaptation Back Pain: A Retrospective Study

Back pain is frequently reported by astronauts during the early phase of space flight as they adapt to the microgravity environment. However, the epidemiology of space adaptation back pain has not been well defined. The purpose of this retrospective study was to develop a case definition of space adaptation back pain, determine the incidence of space adaptation back pain, and determine the effectiveness of available treatments. Medical records from the Mercury, Apollo, Apollo-Soyuz Test Project (ASTP), Skylab, Mir, International Space Station (ISS), and Shuttle programs were reviewed. All episodes of in-flight back pain that met the criteria for space adaptation back pain were recorded. Pain characteristics, including intensity, location, and duration of the pain were noted. The effectiveness of specific treatments also was recorded. The incidence of space adaptation back pain among astronauts was determined to be 53% (384/722). Most of the affected astronauts reported mild pain (85%). Moderate pain was reported by 11% of the affected astronauts and severe pain was reported by only 4% of the affected astronauts. The most effective treatments were fetal positioning (91% effective) and the use of analgesic medications (85% effective). This retrospective study aids in the development of a case definition of space adaptation back pain and examines the epidemiology of space adaptation back pain. Space adaptation back pain is usually mild and self-limited. However, there is a risk of functional impairment and mission impact in cases of moderate or severe pain that do not respond to currently available treatments. Therefore, the development of preventive measures and more effective treatments should be pursued.

Kerstman, E. L.↗
NASA NTRS1994

A retrospective study of promethazine and its failure to produce the expected incidence of sedation during space flight

Since March 1989, intramuscular (IM) promethazine has been successfully used to treat the symptoms of space motion sickness. The incidence of sedation associated with promethazine administration on the ground is large and may result in operational impact. The authors undertook a retrospective study to quantify the incidence of sedation from promethazine use during Space Shuttle flights. Crew medical debriefings from 14 shuttle missions were reviewed for crew members who had been treated with IM promethazine and their corresponding symptoms were identified. Twenty-one crew members received IM promethazine (25-50 mg), and only one experienced any associated sedation with no operational impact. This sedation incidence of less that 5% is in stark contrast to the 60 to 73% incidence of sedation seen in ground-based studies. The incidence of sedation during space flight from IM promethazine is substantially less than that seen on the ground and does not present an operational problem during Space Shuttle flights. Future investigations of environmental stressors and pharmacodynamic changes associated with space flight may explain the huge disparity between the space-flight and ground-based data.

short duration↗
DOE OSTI2024

Health Care Usage During the COVID-19 Pandemic and the Adoption of Telemedicine: Retrospective Study of Chronic Disease Cohorts

Background: The COVID-19 pandemic accelerated telehealth adoption across disease cohorts of patients. For many patients, routine medical care was no longer an option, and others chose not to visit medical offices in order to minimize COVID-19 exposure. In this study, we take a comprehensive multidisease approach in studying the impact of the COVID-19 pandemic on health care usage and the adoption of telemedicine through the first 12 months of the COVID-19 pandemic. Objective: We studied the impact of the COVID-19 pandemic on in-person health care usage and telehealth adoption across chronic diseases to understand differences in telehealth adoption across disease cohorts and patient demographics (such as the Social Vulnerability Index [SVI]). Methods: We conducted a retrospective cohort study of 6 different disease cohorts (anxiety: n=67,578; depression: n=45,570; diabetes: n=81,885; kidney failure: n=29,284; heart failure: n=21,152; and cancer: n=35,460). We used summary statistics to characterize changes in usage and regression analysis to study how patient characteristics relate to in-person health care and telehealth adoption and usage during the first 12 months of the pandemic. Results: We observed a reduction in in-person health care usage across disease cohorts (ranging from 10% to 24%). For most diseases we study, telehealth appointments offset the reduction in in-person visits. Furthermore, for anxiety and depression, the increase in telehealth usage exceeds the reduction in in-person visits (by up to 5%). We observed that younger patients and men have higher telehealth usage after accounting for other covariates. Patients from higher SVI areas are less likely to use telehealth; however, if they do, they have a higher number of telehealth visits, after accounting for other covariates. Conclusions: The COVID-19 pandemic affected health care usage across diseases, and the role of telehealth in replacing in-person visits varies by disease cohort. Understanding these differences can inform current practices and provides opportunities to further guide modalities of in-person and telehealth visits. Critically, further study is needed to understand barriers to telehealth service usage for patients in higher SVI areas. A better understanding of the role of social determinants of health may lead to more support for patients and help individual health care providers improve access to care for patients with chronic conditions.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1976

Retrospective studies of operating problems in air transport

An epidemiological model for the study of human errors in aviation is presented. In this approach, retrospective data are used as the basis for formulation of hypotheses as to system factors which may have contributed to such errors. Prospective experimental studies of aviation operations are also required in order to prove or disprove the hypotheses, and to evaluate the effectiveness of intervention techniques designed to solve operational problems in the aviation system.

Billings, C. E.↗
NASA NTRS2009

Space Adaptation Back Pain: A Retrospective Study

Astronaut back pain is frequently reported in the early phase of space flight as they adapt to microgravity. The epidemiology of space adaptation back pain (SABP) has not been well established. This presentation seeks to determine the exact incidence of SABP among astronauts, develop a case definition of SABP, delineate the nature and pattern of SABP, review available treatments and their effectiveness in relieving SABP; and identify any operational impact of SABP. A retrospective review of all available mission medical records of astronauts in the U.S. space program was performed. It was revealed that the incidence of SABP has been determined to be 53% among astronauts in the U.S. space program; most cases of SABP are mild, self-limited, or respond to available treatment; there are no currently accepted preventive measures for SABP; it is difficult to predict who will develop SABP; the precise mechanism and spinal structures responsible for SABP are uncertain; there was no documented evidence of direction operational mission impact related to SABP; and, that there was the potential for mission impact related to uncontrolled pain, sleep disturbance, or the adverse side effects pf anti-inflammatory medications

Kerstman, Eric↗
NASA NTRS1988

Hydrologic models for land-atmosphere retrospective studies of the use of LANDSAT and AVHRR data

The use of a Geographic Information System (GIS) and LANDSAT analysis in conjunction with the Simulator for Water Resources on a Rural Basin (SWRRB) hydrologic model to examine the water balance on the Little Washita River basin is discussed. LANDSAT analysis was used to divide the basin into eight non-contiguous land covers or subareas: rangeland, grazed range, winter wheat, alfalfa/pasture, bare soil, water, woodland, and impervious land (roads, quarry). The use of a geographic information system allowed for the calculation of SWRRB model parameters in each subarea. Four data sets were constructed in order to compare SWRRB estimates of hydrologic processes using two methods of maximum LAI and two methods of watershed subdivision. Maximum LAI was determined from a continental scale map, which provided a value of 4.5 for the entire basin, and from its association with the type of land-cover (eight values). The two methods of watershed subdivision were determined according to drainage subbasin (four) and the eight land-covers. These data sets were used with the SWRRB model to obtain daily hydrologic estimates for 1985. The results of the one year analysis lead to the conclusion that the greater homogeneity of a land-cover subdivision provides better water yield estimates than those based on a drainage properties subdivision.

Duchon, Claude E.↗
NASA NTRS1988

Hydrologic models for land-atmosphere retrospective studies of the use of LANDSAT and AVHRR data

The use of a Geographic Information System (GIS) and LANDSAT analysis in conjunction with the Simulator for Water Resources on a Rural Basin (SWRRB) hydrologic model to examine the water balance on the Little Washita River basin is discussed. In the research completed to date LANDSAT analysis was used to divide the basin into eight non-contiguous land covers or sub areas. The use of a geographic informatin system allowed for the calculation of SWRRB model parameters in each subarea. Four data sets were constructed in order to compare SWRRB estimates of hydrologic processes using two methods of maximum LAI and two methods of watershed division. These data sets were used with the SWRRB model to obtain daily hydrologic estimates for 1985.

Duchon, Claude E.↗
NASA NTRS1992

Secular Variation Across the Oceans: a Retrospective Study from 35 Years of Shipboard Total Field Measurements in the NE Atlantic

This is a pilot study to determine whether secular variation information can be retrieved from underway shipboard total field measurements with sufficient accuracy to complement geomagnetic data from land-based observatories. Applying the various new techniques described in this report, we extracted values of the total field at 42,677 crossovers or ship track intersection points contained in data sets collected between 18 degrees N and 50 degress N in the NE Atlantic, and extending temporally from 1955 to 1990. We used an edited subset of these total field values to derive the secular variation at 30,140 different locations in the study area, and compared the results with DGRF secular variation over the study area, calculated at 5 year intervals. The derived and DGRF values agree well, showing that indeed marine data can be a source for secular variations. However the analysis demonstrated that due to inherent noise in the marine data, only minor improvements on the DGRF values for the secular variation can be achieved.

Williams, C. A.↗
NASA NTRS2011

Retrospective Study of Serum Sclerostin Measurements in Bed Rest Subjects

Animal models and human studies suggest that osteocytes regulate the skeleton s response to mechanical unloading at the cellular level in part by an increase in sclerostin, an inhibitor of the anabolic Wnt pathway. However, few studies have reported changes in serum sclerostin in humans exposed to reduced mechanical loading. Thus, we determined changes in serum sclerostin and bone turnover markers in healthy adult men who participated in a controlled bed rest study. Seven healthy adult men (31 +/- 3 yrs old) underwent 90-day six-degree head down tilt bed rest at the University of Texas Medical Branch in Galveston's Institute for Translational Sciences - Clinical Research Center (ITS-CRC). Serum sclerostin, PTH, serum markers of bone turnover (bone specific alkaline phosphatase, RANKL/OPG, and osteocalcin), urinary calcium and phosphorus excretion, and 24 hour pooled urinary markers of bone resorption (NTX, DPD, PYD) were evaluated pre-bed rest (BL), bed rest day 28 (BR-28), bed rest day 60 (BR-60), and bed rest day 90 (BR-90). In addition, bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DXA) at BL, BR-60, and post bed rest day 5 (BR+5). Data are reported as mean +/- standard deviation. We used repeated measures ANOVA to compare baseline values to BR-28, BR-60, and BR-90. RESULTS Consistent with prior reports, BMD declined significantly (1-2% per month) at weight-bearing skeletal sites (spine, hip, femur neck, and calcaneus). Serum sclerostin levels were elevated above BL at BR-28 (+29% +/- 20%, p = 0.003), BR-60 (+42% +/- 31%, p < 0.001), and BR-90 (22% +/- 21%, p = 0.07). Serum PTH levels were reduced at BR-28 (-17% +/- 16%, p = 0.02), BR-60 (-24% +/- 14%, p = 0.03), and returned to baseline at BR-90 (-21% +/- 21%, p = 0.14). Serum bone turnover markers did not change, however urinary bone resorption markers and calcium were significantly elevated following bed rest (p < 0.01). CONCLUSION We observed an increase of serum sclerostin associated with decreased serum PTH and elevated bone resorption markers in otherwise healthy men subjected to long-term immobilization.

Spatz, J. M.↗
NASA NTRS2016

Analysis by NASA's VESGEN Software of Retinal Blood Vessels Before and After 70-Day Bed Rest: A Retrospective Study

Significant risks for visual impairment associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions. Impairments include decreased near visual acuity, posterior globe flattening, choroidal folds, optic disc edema and cotton wool spots. We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal blood vessels that precede development of visual and other ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated by NASAs innovative VESsel GENeration Analysis (VESGEN) software for two studies: (1) head-down tilt in human subjects before and after 70 days of bed rest, and (2) U.S. crew members before and after ISS missions. VESGEN analysis in previous research supported by the US National Institutes of Health identified surprising new opportunities to regenerate retinal vessels during early-stage, potentially reversible progression of the visually impairing and blinding disease, diabetic retinopathy.

Vascular↗
NASA NTRS2017

Mapping by VESGEN of Blood Vessels in the Retinas of Astronauts Pre- and Post-Flight to the ISS

Research by NASA [1] established that significant risks for visual and ocular impairments associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions. It is well established in physiology and pathology that a fundamental role of the microvasculature is to mediate fluid transfers and remodel actively in response to environmental, immune and other stresses. We therefore hypothesize that remodeling of retinal blood vessels necessarily occurs during accommodation of microgravity-induced fluid shifts prior to subsequent development of visual and ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated by NASA's innovative VESsel GENeration Analysis (VESGEN) software for two studies: (1) U.S. crew members before and after ISS missions, and (2) head-down tilt in human subjects before and after 70 days of bed rest. We anticipate that results of the two studies will be complete by the Investigators Workshop (January 22, 2017). METHODS: For the 2013 NASA NRA award, we are concluding the analysis of 30 degree infrared (IR) Heidelberg Spectralis images of retinal blood vessels by VESGEN (patents pending), a mature, automated software developed as a translational and basic vascular research discovery tool, particularly for retinal vascular disease. Subjects of our retrospective study include eight ISS crew members monitored for routine occupational surveillance pre- and post-flight, who provided their study consents to NASAs Lifetime Surveillance of Astronaut Health (LSAH) in coordination with approval of the VESGEN retrospective study protocol by NASAs Institutional Review Board (IRB). The ophthalmic retinal images (average image resolution, approximately 5.6 microns per pixel) are blinded as to pre and post ISS status until the second portion of our study, when VESGEN results will be correlated with other ophthalmic and medical findings for the crew members. Due to image resolution challenges, a novel Matlab tool was developed for aligning pre and post images, and comparing (querying) the two images for differences in the morphology of small vessels. RESULTS: During the past year, LSAH approved the release of all astronaut retinal images to our study for VESGEN analysis. Substantial progress on the initial blinded portion of the study is in place. We anticipate that VESGEN analysis of the 32 Spectralis IR retinal images will be complete for presentation at the 2017 IWS meeting. CONCLUSIONS: Modified retinal vascular patterning may offer early-stage predictions of ocular changes resulting in decreased visual acuity for the VIIP syndrome. Novel insights provided by VESGEN into progressively pathological and blinding vascular remodeling in the human retina currently help to guide other NIH- and NASA-supported therapeutic studies of retinal disease and modeling of the VIIP risk. Results of our vascular investigation of the retinas of astronauts pre- and post-flight may help advance the understanding of both healthy and pathological adaptations to fluid shifts in microgravity associated with the VIIP syndrome. Preliminary results indicate that imaging of higher resolution, such as the new OCT angiography (OCT-A) technology, will be required to determine conclusively the role of the smaller retinal and choroidal vessels in VIIP etiology.

VESGEN↗
DOE OSTI2026

Identification of drug repurposing candidates for amyotrophic lateral sclerosis using electronic health records: a retrospective cohort study

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with a life expectancy of only 3–5 years and few approved treatments. To identify drug repurposing candidates for the treatment of ALS, we analysed the electronic health records (EHRs) of a large cohort of military veterans with ALS. We analysed the EHRs of individuals in the US Veterans Health Administration (VHA) database who were diagnosed with ALS between Jan 1, 2009 and Dec 31, 2019 to assess medication effects. Individuals without recorded prescriptions after the date of diagnosis were excluded. Two sets of criteria were applied to ascertain exposure. Exposure criteria A were met if the dispense date or the end date of the medication was within 12 months of ALS diagnosis and the end date was at least 6 months after the dispense date. Exposure criteria B were met if there were at least two dispenses within 6 months before diagnosis and 12 months after diagnosis. Propensity score-matched control groups were generated on the basis of confounders included in the EHR, with methodology of potential outcomes used to infer treatment effects. The primary outcome was death. A standard Cox proportional hazards analysis was done to assess association with survival. Survival was defined as the time from diagnosis date recorded in the EHR to death reported in the Department for Veterans Affairs Vital Status File. Follow-up survival time was censored on Dec 31, 2020, for those alive on this date. Downstream protein targets of drugs with clinically significant effects were analysed using the protein–protein interaction networks-based algorithm PathFX. The EHRs of 11 003 individuals with ALS in the VHA database were appropriate for analysis. 162 medications with treatment groups of 30 or more individuals were identified. Among these 162 medications, 27 were associated with statistically significant changes (≥0·1) in the hazard ratio (HR) for death. 18 of the medications were associated with a reduced HR for death (prolonged survival), and nine were associated with an increased HR for death (reduced survival). Drugs associated with reduced HR included HMG-CoA reductase inhibitors (simvastatin, pravastatin, lovastatin, and atorvastatin), PDE5 inhibitors (vardenafil and sildenafil), and α-adrenergic antagonists (tamsulosin and terazosin). The medications associated with an increased HR were drugs used either in the management of clinical features of ALS associated with poor outcomes or in end-of-life care. PathFx analysis identified a complex of proteins interacting with several of the identified drugs. To our knowledge, this analysis is the largest EHR-based study for identifying drug repurposing candidates for ALS. We identified several drugs that warrant further assessment as therapeutic options in ALS, as well as a protein network complex that might serve as a therapeutic target for ALS.

Reimer, Richard J. [Stanford Univ., CA (United Sta↗
DOE OSTI2025

Comparison of Expert Vocabulary Usage Patterns Between Mental Health and Nonmental Health Clinicians When Diagnosing Pediatric Anxiety Disorders

Objective: To compare the utilization patterns of expert vocabulary (EVo) in diagnosing pediatric anxiety between mental health and non-mental health clinical notes from electronic health records to understand the role of Evo in informing classification and decision-making in anxiety diagnoses. Study design: We conducted a retrospective study using a cohort less than age 25 from Cincinnati Children's Hospital including 897 685 patients with 61 586 446 notes. We analyzed EVo, collected from mental health clinicians, in both mental and nonmental health notes. We compared classification accuracy using EVo-based patient-level embedding from all clinical notes, mental-health notes, and nonmental health notes for 2 tasks: 1) pre-vs postdiagnosis anxiety patients, and 2) prediagnosis anxiety vs nonanxiety patients. Results: EVo usage was highest in prediagnosis anxiety, lower in nonanxiety, and lowest in post-diagnosis. Classification models using EVo features from all, mental-health, and non-mental health notes showed similar F1 scores for prediagnosis anxiety (0.70 ± 0.2 for 2 categories). For anxiety vs nonanxiety classification, all clinical and nonmental health notes had better F1 scores than mental-health notes (above 0.90 for 3 categories). There was a notable difference in class-wise performance across both tasks. Conclusions: There are significant differences in anxiety EVo use between mental health and nonmental health clinicians. Despite less anxiety-specific terminology, non-mental health notes still captured key aspects of patient presentations, emphasizing the importance of including all clinicians' notes in analysis. EVo's utility for anxiety classification is most effective in prediagnostic phases, suggesting the need for a dedicated diagnostic lexicon and further study before incorporating EVo into classification models.

feature engineering↗
NASA NTRS1998

Heart rate dynamics in patients with stable angina pectoris and utility of fractal and complexity measures

Dynamic analysis techniques may uncover abnormalities in heart rate (HR) behavior that are not easily detectable with conventional statistical measures. However, the applicability of these new methods for detecting possible abnormalities in HR behavior in various cardiovascular disorders is not well established. Conventional measures of HR variability were compared with short-term (< or = 11 beats, alpha1) and long-term (> 11 beats, alpha2) fractal correlation properties and with approximate entropy of RR interval data in 38 patients with stable angina pectoris without previous myocardial infarction or cardiac medication at the time of the study and 38 age-matched healthy controls. The short- and long-term fractal scaling exponents (alpha1, alpha2) were significantly higher in the coronary patients than in the healthy controls (1.34 +/- 0.15 vs 1.11 +/- 0.12 [p <0.001] and 1.10 +/- 0.08 vs 1.04 +/- 0.06 [p <0.01], respectively), and they also had lower approximate entropy (p <0.05), standard deviation of all RR intervals (p <0.01), and high-frequency spectral component of HR variability (p <0.05). The short-term fractal scaling exponent performed better than other heart rate variability parameters in differentiating patients with coronary artery disease from healthy subjects, but it was not related to the clinical or angiographic severity of coronary artery disease or any single nonspectral or spectral measure of HR variability in this retrospective study. Patients with stable angina pectoris have altered fractal properties and reduced complexity in their RR interval dynamics relative to age-matched healthy subjects. Dynamic analysis may complement traditional analyses in detecting altered HR behavior in patients with stable angina pectoris.

NASA Discipline Cardiopulmonary↗
NASA NTRS1988

Long-term follow up of astronaut health indices

Ground-based research and reevaluation of flight data is currently in progress in order to develop suitable and operationally acceptable medical standards for extended-duration manned space missions. The large amount of data obtained thus far constitutes a unique data base representative of the astronaut population. In this paper, preliminary 10-year findings of prospective studies established in 1977 are described, and results obtained from retrospective studies conducted on data accumulated prior to the 1977 establishment of medical selection standards are summarized.

Nicogossian, A. E.↗
NASA NTRS2017

Analysis by NASA's VESGEN Software of Retinal Blood Vessels in Human Subjects Undergoing Head-Down Tilt During 70-Day Bed Rest

Significant risks for visual impairment associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions [1]. We hypothesize that microgravity-induced fluid shifts result in pathological changes within blood vessels of the retina that precede development of visual and other ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated for two studies in 30deg infrared (IR) Heidelberg Spectralis(Registered Trademark) images with NASA's innovative VESsel GENeration Analysis (VESGEN) software [2,3]. The retrospective studies include: (1) before, during and after (pre, mid and post) 6º head-down tilt (HDT) in human subjects during 70 days of bed rest, and (2) before and after missions to the International Space Station (ISS) by U.S. crew members. Results for both studies are almost complete. A preliminary example for HDT is described below.

Microgravity↗