166 research outputs found

    Blowing cold air to treat acute brain injuries

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    A structured-light surface scanning system to evaluate breast morphology in standing and supine positions

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    Objective and accurate surface measurements of the human breast are important for surgical planning and outcome assessment. Breast shapes are affected by gravitational loads and deformities, and the measurements obtained in the standing position may not correlate well with measurements in supine position, which is more representative of breast surgery. To evaluate the effect of changes in body posture on breast morphology, a dual color 3D surface imaging system capable of scanning patients in both the supine and standing positions was developed. System performance was established by assessing the surface coverage and accuracy between a CAD breast model and 3D surface scans of a 3D print of the CAD model. The modular nature of the system offers the potential to add additional surface scanners with unique colors to increase coverage without sacrificing speed. The human pilot study shows that the system can quantitatively evaluate the effect of subject postures in individuals with smaller breasts, and thereby has the potential to be used to investigate changes in breast morphologies

    Animal models of atherosclerosis.

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    Atherosclerosis is a significant cause of morbidity and mortality globally. Many animal models have been developed to study atherosclerosis, and permit experimental conditions, diet and environmental risk factors to be carefully controlled. Pathophysiological changes can be produced using genetic or pharmacological means to study the harmful consequences of different interventions. Experiments using such models have elucidated its molecular and pathophysiological mechanisms, and provided platforms for pharmacological development. Different models have their own advantages and disadvantages, and can be used to answer different research questions. In the present review article, different species of atherosclerosis models are outlined, with discussions on the practicality of their use for experimentation.GT was supported by a BBSRC Doctoral Training Award and thanks the Croucher Foundation of Hong Kong for the generous support of his clinical assistant professorship. YC is supported by the ESRC

    Has increased clinical experience with methotrexate reduced the direct costs of medical management of ectopic pregnancy compared to surgery?

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    <p>Abstract</p> <p>Background</p> <p>There is a debate about the cost-efficiency of methotrexate for the management of ectopic pregnancy (EP), especially for patients presenting with serum human chorionic gonadotrophin levels of >1500 IU/L. We hypothesised that further experience with methotrexate, and increased use of guideline-based protocols, has reduced the direct costs of management with methotrexate.</p> <p>Methods</p> <p>We conducted a retrospective cost analysis on women treated for EP in a large UK teaching hospital to (1) investigate whether the cost of medical management is less expensive than surgical management for those patients eligible for both treatments and (2) to compare the cost of medical management for women with hCG concentrations 1500–3000 IU/L against those with similar hCG concentrations that elected for surgery. Three distinct treatment groups were identified: (1) those who had initial medical management with methotrexate, (2) those who were eligible for initial medical management but chose surgery (‘elected’ surgery) and (3) those who initially ‘required’ surgery and did not meet the eligibility criteria for methotrexate. We calculated the costs from the point of view of the National Health Service (NHS) in the UK. We summarised the cost per study group using the mean, standard deviation, median and range and, to account for the skewed nature of the data, we calculated 95% confidence intervals for differential costs using the nonparametric bootstrap method.</p> <p>Results</p> <p>Methotrexate was £1179 (CI 819–1550) per patient cheaper than surgery but there were no significant savings with methotrexate in women with hCG >1500 IU/L due to treatment failures.</p> <p>Conclusions</p> <p>Our data support an ongoing unmet economic need for better medical treatments for EP with hCG >1500 IU/L.</p

    Onset Rivalry: Brief Presentation Isolates an Early Independent Phase of Perceptual Competition

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    When the left and right eyes are simultaneously presented with different images, observers typically report exclusive awareness of only one image. This phenomenon is termed binocular rivalry, reflecting the fact that the dominant image alternates every few seconds in a cycle of perceptual competition that continues indefinitely. Despite the apparent continuity in perceptual switching, we now demonstrate that the initial “onset” period is fundamentally different to all subsequent rivalry epochs. Using brief intermittent presentations, rivalry dominance shows strong biases such that the same target is perceived with each successive stimulus onset. These biases remain consistent within any given location, but vary across the visual field in a distribution that is stable over multiple weeks but highly idiosyncratic across observers. If the presentation exceeds ∌1sec at any location, however, the very different and much more balanced alternations of sustained binocular rivalry become apparent. These powerful onset biases are observed with brief intermittent presentations at a single location or with continual smooth motion of the targets. Periods of adaptation to one of the rivaling targets induced local switches in dominance to the non-adapted target. However, these effects were generally limited to the spatial site of adaptation and had less influence over each subsequent cycle of the target. We conclude that onset rivalry is independent of sustained rivalry and cannot be explained by local regions of monocular dominance or memory of past perceptual history, but rather reflects low-level, spatially localized factors that are stable over periods of weeks. These findings suggest that brief presentation paradigms are inappropriate for their current use in studies of the mechanisms underlying sustained rivalry. However, brief presentations are ideal for investigating early stages of perceptual competition

    Five‐year effectiveness of bariatric surgery on disease remission, weight loss, and changes of metabolic parameters in obese patients with type 2 diabetes: A population‐based propensity score‐matched cohort study

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    Aims: To compare disease remission rates, weight loss, and changes of metabolic parameters of patients after bariatric surgery with nonsurgical patients. Methods: Based on the 2006‐2017 Hospital Authority database, a population‐based retrospective cohort of obese type 2 diabetes mellitus (T2DM) patients with and without bariatric surgery were identified. Surgical patients were matched with nonsurgical patients on 1‐to‐5 propensity score. Remission rates of diabetes, hypertension, and dyslipidaemia were reported annually up to 60 months. Changes in weight loss measurements (Body Mass Index [BMI], percentage of total weight loss [%TWL], percentage of excess weight loss [%EWL], and percentage of rebound in excess weight loss [%REWL]) and metabolic parameters (haemoglobin A1c [HbA1c], systolic blood pressure [SBP], diastolic blood pressure [DBP], and low‐density lipoprotein cholesterol [LDL‐C]) were measured for both groups. Results: Four hundred one surgical patients (310 restrictive surgeries; 91 bypass surgeries) and 1894 nonsurgical patients were included. Surgical patients had higher remission rates in diabetes and dyslipidaemia and better glycaemic control at 12 to 60 months (all Ps &lt; .01). SBP and DBP were significantly lower for surgical group up to 12 months and similar between two groups after 12 months. Surgical patients had significantly lower BMI during follow‐up period. %TWL and %EWL were higher in the surgery group (15.7% vs 3.7%; 48.8% vs 12.0%) at 60 months (P &lt; .001); differences in %REWL between two groups were insignificant. The effectiveness of restrictive and bypass surgeries was similar at 60 months, although restrictive surgeries were slightly more effective in T2DM remission. Conclusions: Bariatric surgery was effective in weight loss, remission of diabetes, and dyslipidaemia in 5‐year post‐surgery

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 ÎŒm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
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