Pettyandresen9070

INTRODUCTION The Integrated Medical Model (IMM) is a quantified, evidence-based decision support tool developed by National Aeronautics and Space Administration (NASA) to assist in the assessment of the medical risk of human spaceflight missions. The IMM utilizes a probabilistic risk assessment (PRA) approach to simulate potential in-flight medical events and resultant health and mission outcomes.METHODS The IMM has been utilized to estimate the medical risk associated with International Space Station (ISS) missions. The IMM outputs that have been most informative to the ISS program are the probabilities of evacuation (pEVAC) and loss of crew life (pLOCL). These outputs are incorporated into a continuously maintained ISS PRA model so that its quantification of total ISS mission risk includes the medical risk.RESULTS Results of this analysis revealed that the forecasted risk values of pEVAC and pLOCL due to medical events were improved by using the IMM with the ISS PRA model instead of using data from prior sources in which these values were underestimated.DISCUSSION The IMM provides an evidence-based PRA approach to directly communicate and integrate medical risk with other ISS risks. A comparison of IMM outputs of pEVAC and pLOCL to empirical spaceflight data and analog population data revealed that IMM outputs were comparable with actual experience. With appropriate outcome context, these findings increase subject matter expert confidence in the accuracy of IMM risk estimates. IMM outputs provide quantifiable objective estimates of medical risk that can be used to inform mission risk assessments and to optimize crew health.Walton ME, Kerstman EL. Quantification of medical risk on the International Space Station using the Integrated Medical Model. Aerosp Med Hum Perform. 2020; 91(4)332-342.BACKGROUND Aerobatic flight is a challenge for the vestibular system, which is likely to lead to adaptive changes in the vestibular responses of pilots. We investigated whether aerobatic pilots, as individuals who experience intense vestibular stimulation, present modifications of the vestibular-ocular reflex, motion sickness susceptibility and intensity, visual vertical estimation, and visual dependence as compared to normal volunteers.METHODS To evaluate vestibulo-ocular reflexes, eye movements were recorded with videonystagmography while subjects were rotated on a rotatory chair with the axis of rotation being vertical (canal-ocular reflex) or inclined to 17° (otolith-ocular reflex). Motion sickness was evaluated after the rotatory test using the Graybiel diagnostic criteria. General motion sickness susceptibility and visual field dependence were also evaluated.RESULTS Averaged data did not show significant difference in canal-ocular reflex and otolith ocular-reflex between groups. However, a significant asymmetry in otolith-driven ocular responses was found in pilots (CW 0.50 ± 1.21° · s-1 vs. CCW 1.59 ± 1.12° · s-1), though visual vertical estimation was not altered in pilots and both groups were found field independent. Pilots were generally less susceptible to motion sickness (MSSQ scores 2.52 ± 5.59 vs. 13.5 ± 11.36) and less affected by the nauseogenic stimulation (Graybiel diagnostic criteria 3.36 ± 3.81 vs. 8.39 ± 7.01).DISCUSSION We did not observe the expected habituation in the group of aerobatic pilots. However, there was a significant asymmetry in the otolith-driven ocular responses in pilots, but not in the controls, which may result from the asymmetry in piloting protocols.Kuldavletova O, Tanguy S, Denise P, Quarck G. Vestibulo-ocular responses, visual field dependence, and motion sickness in aerobatic pilots. Aerosp Med Hum Perform. 2020; 91(4)326-331.BACKGROUND General Aviation (GA) pilots who encounter hazardous weather inflight have a high probability of incurring fatal accidents. To mitigate this problem, previous research investigated pilot decision making and the effects of new technology. Limited investigations have examined usability and interpretability of observation and forecast weather products available to pilots. Therefore, this study examined the interpretability of weather observation and forecast reports that GA pilots use for preflight weather planning and the impact of pilot certification level on the interpretability of these displays.METHOD There were 204 GA pilots (Mean age = 22.50 yr; Median flight hours = 131.0) who completed a 90-item multiple choice Aviation Weather Product Test. The questions portrayed static weather displays available on the NOAA/National Weather Service Aviation Weather Center website. The questions were designed to have high cognitive fidelity in comparison with preflight weather planning tasks.RESULTS The results revealed overall low mean interpretability scores (Mean percent correct= 59.29%, SD = 16.01%). The scores for observation products and product attributes were lower for student pilots than experienced pilots. Forecast product scores for student and private pilots did not differ, however, student pilot scores were significantly lower than instrument rated private and commercial pilots.DISCUSSION The low interpretability scores indicate that GA pilots misinterpret weather information provided by most weather observation and forecast products. Possible contributing factors to the low product interpretation scores include poor usability and a lack of training. Future research should measure the usability of weather displays designed for pilots.Blickensderfer BL, Guinn TA, Lanicci JM, Ortiz Y, King JM, Thomas RL, DeFilippis N. Interpretability of aviation weather information displays for general aviation. Aerosp Med Hum Perform. 2020; 91(4)318-325.BACKGROUND Airsickness is a clinical syndrome manifesting in a variety of symptoms, particularly nausea and vomiting during flight. Studies of habituation to motion sickness in humans treated by scopolamine have produced conflicting results. The drug accelerated habituation, but a rebound effect on symptom severity was observed after its withdrawal. The purpose of the present study was to investigate whether scopolamine affects the adaptation process. We also evaluated the relationship between initial symptom severity and adaptation to airsickness.METHODS Aviator cadets in the first two stages of their training were divided into two groups, treated and not treated by scopolamine. Airsickness severity was evaluated using both simulator sickness and motion sickness questionnaires, and drug administration was recorded.RESULTS A statistically significant higher rate of adaptation was observed among the scopolamine-treated group compared with the nontreated group. On the simulator sickness questionnaire, rate of adaptation for the two groups was -0.21 ± 0.53 and -0.1 ± 0.17, respectively, and for the motion sickness questionnaire -2.34 ± 1.54 and -0.91 ± 1.41, respectively. Examination of a possible connection between initial symptom severity and adaptation rate failed to reveal a significant relationship.CONCLUSIONS We recommend the use of oral scopolamine to accelerate habituation and find it a relatively safe short-term treatment for airsickness. Our results support the notion that scopolamine accelerates the natural adaptation process.Doron O, Samuel O, Karfunkel-Doron D, Tal D. Scopolamine treatment and adaptation to airsickness. Aerosp Med Hum Perform. 2020; 91(4)313-317.KSL-W peptide has demonstrated antibacterial and antifungal activity and inhibitory effects against oral biofilm. This study aimed to check out the effect of chlorhexidine (CLX) or KSL-W peptide-loaded poloxamer 407-based microemulsions for buccal delivery on Fusobacterium nucleatum (F. nucleatum) biofilm. The formulation (F) containing 10% copolymer poloxamer 407 dispersion (1%), 40% oleic acid and 50% PPG-5-CETETH-20 was characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), rheology, bioadhesive and syringeability; and in the treatment of a biofilm produced by F. nucleatum. The darkfield images obtained by PLM and the SAXS curves with an extended peak indicated that the system was characteristic of microemulsions. In a continuous analysis, microemulsions exhibited Newtonian behavior. In frequency, the oscillatory analysis profile presented predominantly viscous behavior. Bioadhesive force detected in the analysis of F (7.4 ± 1.81 mN˙ s) and syringeability (17.83± 5.97 N · mm) being adequate values for buccal administration. After 4 h, KSL-W-loaded F shown over 20% higher effectiveness than chlorhexidine-loaded microemulsions. In conclusion, the KSL-W-loaded microemulsions showed a considerable reduction in F. nucleatum biofilm formation and presented promising structural properties for buccal drug delivery.Resveratrol (RES) is a natural non-flavonoid polyphenol with cardioprotective activities, antioxidant, antiplatelet, and antiinflammatory. However, its low aqueous solubility, chemical stability, and oral bioavailability, as well as a short circulation half-life greatly limit its clinical applications. To overcome these limitations of RES, we synthesized a methoxy poly(ethylene glycol)-b-oligomerization(D, L-Leucine) (mPEG-b-O(D, L-Leu)) nanoparticle (NP) as the carrier of RES and evaluated the myocardial-protective effectiveness of this RES/NP complex in rat myocardial ischemia-reperfusion injury models. We gauged the characterization of the NP through proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, transmission electron microscope, and Fourier transform infrared spectroscopy and then loaded RES on the nanocarrier by hydrophobic interactions under physiological pH to extend the release time of RES and prolong its circulation half-life. Subsequently, we used rat cardiomyocytes (H9C2 cells) and rat MI/RI model to investigate the relationship between drug composition and myocardial preservation properties. It was found that RES was encapsulated quickly and efficiently, and displayed an effectual loading-capacity and in vitro sustained-release. AZD3514 Anti-MI/RI effect of the RES/NP complex was found satisfactory in rat models in vivo using free RES as the control. This study suggested that NP may prove to be a potent nanocarrier to augment the pharmacotherapy of RES against MI/RI.Titanium dioxide nanoparticles (TiO₂ NPs) are largely manufactured and extensively applied for the treatment of environmental pollution. Studies have proved that exposure to TiO₂ NPs leads to toxicity of the reproductive system. However, very few studies have highlighted the involvement of nuclear factor erythroid-2 related factor 2 (Nrf2) under TiO₂ NPinduced spermatogenic apoptosis. Our findings suggested that TiO₂ NPs could cross the blood-testis barrier and were aggregated or deposed in spermatogenic cells, which resulted in spermatogenic apoptosis. Furthermore, exposure to TiO₂ NPs caused an overproduction of reactive oxygen species and the peroxidation of lipids, proteins, and DNA. Such exposure also caused significant decreases in the activities of SOD, GSH-PX, GST, and GSH content in the testis. Importantly, exposure to TiO₂ NPs resulted in an up-regulation of Keap1 expression and a down-regulation of Nrf2 and its target gene products, NQO1, HO-1, GCLC, PKC, and PI3K. The present study implies that TiO₂ NPs could lead to spermatogenic apoptosis, and Nrf2 is the initial factor that responded to such reproductive toxicity by regulating the expression of antioxidative proteins.