43 research outputs found

    Hypergravity effects on glide arc plasma

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    The behaviour of a special type of electric discharge – the gliding arc plasma – has been investigated in hypergravity (1g –18g) using the Large Diameter Centrifuge (LDC) at ESA/ESTEC. The discharge voltage and current together with the videosignal from a fast camera have been recorded during the experiment. The gliding of the arc is governed by hot gas buoyancy and by consequence, gravity. Increasing the centrifugal acceleration makes the glide arc movement substantially faster. Whereas at 1g the discharge was stationary, at 6g it glided with 7 Hz frequency and at 18g the gliding frequency was 11 Hz. We describe a simple model for the glide arc movement assuming low gas flow velocities, which is compared to our experimental results

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    The Cost Effectiveness of Stratified Care in the Management of Migraine

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    Objective: To examine the cost effectivess of a stratified-care regimen for patients with migraine - in which patients are stratified by severity of illness, and then prescribed differing treatments according to level of severity - compared with a conventional stepped-care approach. Design and methods: A decision analytic model was constructed to simulate a controlled clinical trial in which patients with migraine receiving primary medical care were randomly assigned to treatment under a stepped-care or a stratified-care regimen. A health service payer perspective was adopted and the time horizon was 1 year. Data inputs were: 1. the frequency and disability of migraine, derived from population-based studies; 2. disability level-specific treatment response rates for over-the-counter analgesics,aspirin/metoclopramide and zolmitriptan as the representative of high-end therapy obtained from an international consensus opinion enquiry; and 3. unit costs of healthcare obtained from UK health service sources. Main outcome measures and results: The estimated 1-year direct healthcare costs per primary care patient with migraine were pound sterling (Lstg ) 156.82 for stepped care and Lstg 151.57 for stratified care. Estimates of treatment response rates were 40 and 71% for stepped and stratified care, respectively. The cost per successfully treated attack was Lstg 23.43 for stepped care and Lstg 12.60 for stratified care. Stratified care remained cost effective when tested in a wide range of one-way sensitivity analyses, and probabilistic sensitivity analysis showed the cost effectiveness of stratified care to be significant at the 3% level. Conditional confidence analysis showed that the level of confidence in the cost effectiveness of stratified care varied positively with the case mix, i.e. in populations where the proportion of moderate and severely disabled patients with migraine was greater than 25%, the cost effectiveness of stratified care remained statistically significant. Conclusion: A stratified-care treatment strategy (including zolmitriptan as the representative of high-end therapy) is a highly cost-effective method of managing migraine in the primary care setting compared with stepped care, delivering improved clinical outcomes at no additional cost.Analgesics, Antimigraines, Aspirin, Cost analysis, Metoclopramide, Migraine, Pharmacoeconomics, Zolmitriptan

    Modelling the relationship between isokinetic muscle strength and sprint running performance.

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    Muscle strength is thought to be a major factor in athletic success. However, the relationship between muscle strength and sprint performance has received little attention. The aim of this study was to examine the relationship in elite performers of isokinetic muscle strength across three lower limb joints and sprinting performance, including the use of theoretical models. Eight rugby players, eight track sprinters and eight competitive sportsmen, all elite national or regional competitors, performed sprints over 15 m and 35 m with times recorded over 0-15 m and 30-35 m. Isokinetic torque was measured at the knee, hip and ankle joints at low (1.05 rad s(-1)), intermediate (2.09 or 2.62 rad s(-1)) and high (3.14 or 4.19 rad s(-1)) speeds during concentric and eccentric muscle actions. Using linear regression and expressing sprint performance as time, the strongest relationship, for the joint actions and speeds tested, was between concentric knee extension at 4.19 rad s(-1) and sprint performance (0-15 m times: r=-0.518, P< 0.01; 30-35 m times: r=-0.688, P< 0.01). These relationships were improved for 0-15 m, but not for 30-35 m, by expressing torque relative to body mass (0-15 m times: r=-0.581; 30-35 m times: r=-0.659). When 0-15 m performance was expressed as acceleration rather than time, the correlation was improved slightly (r=0.590). However, when the data (0-15 m times) were fitted to the allometric force model proposed by Gunther, 77% of the variance in concentric knee extension torque at 4.19 rad s(-1) could be explained by 0-15 m times, limb length (knee to buttocks) and body mass. The fitted parameters were similar to those from the theoretical model. These findings suggest that the relationship between isokinetic muscle strength and sprint performance over 0-15 m (during the acceleration phase) is improved by taking limb length and body mass into account

    Stability Studies of UV Laser Irradiated Promethazine and Thioridazine after Exposure to Hypergravity Conditions

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    Pharmaceuticals carried into space are subjected to different gravitational conditions. Hypergravity is encountered in the first stage, during spacecraft launching. The stability of medicines represents a critical element of space missions, especially long-duration ones. Therefore, stability studies should be envisaged before the implementation of drugs for future deep space travel, where the available pharmaceuticals would be limited and restocking from Earth would be impossible. Multipurpose drugs should be proposed for this reason, such as phenothiazine derivatives that can be transformed by optical methods into antimicrobial agents. Within this preliminary study, promethazine and thioridazine aqueous solutions were exposed to UV laser radiation that modified their structures and generated a mixture of photoproducts efficient against particular bacteria. Sub-sequently, they were subjected to 20 g in the European Space Agency’s Large Diameter Centrifuge. The aim was to evaluate the impact of hypergravity on the physico-chemical and spectral properties of unirradiated and laser-irradiated medicine solutions through pH assay, UV-Vis/FTIR absorption spectroscopy, and thin-layer chromatography. The results revealed no substantial alterations in centrifuged samples when compared to uncentrifuged ones. Due to their stability after high-g episodes, laser-exposed phenothiazines could be considered for future space missions
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