161 research outputs found

    Prehospital critical care is associated with increased survival in adult trauma patients in Scotland

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    Background Scotland has three prehospital critical care teams (PHCCTs) providing enhanced care support to a usually paramedic-delivered ambulance service. The effect of the PHCCTs on patient survival following trauma in Scotland is not currently known nationally. Methods National registry-based retrospective cohort study using 2011-2016 data from the Scottish Trauma Audit Group. 30-day mortality was compared between groups after multivariate analysis to account for confounding variables. Results Our data set comprised 17 157 patients, with a mean age of 54.7 years and 8206 (57.5%) of male gender. 2877 patients in the registry were excluded due to incomplete data on their level of prehospital care, leaving an eligible group of 14 280. 13 504 injured adults who received care from ambulance clinicians (paramedics or technicians) were compared with 776 whose care included input from a PHCCT. The median Injury Severity Score (ISS) across all eligible patients was 9; 3076 patients (21.5%) met the ISS>15 criterion for major trauma. Patients in the PHCCT cohort were statistically significantly (all p < 0.01) more likely to be male; be transported to a prospective Major Trauma Centre; have suffered major trauma; have suffered a severe head injury; be transported by air and be intubated prior to arrival in hospital. Following multivariate analysis, the OR for 30-day mortality for patients seen by a PHCCT was 0.56 (95% CI 0.36 to 0.86, p=0.01). Conclusion Prehospital care provided by a physician-led critical care team was associated with an increased chance of survival at 30 days when compared with care provided by ambulance clinicians

    Percutaneous radiologically guided gastrostomy tube placement: comparison of antegrade transoral and retrograde transabdominal approaches

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    PURPOSE:We aimed to compare the antegrade transoral and the retrograde transabdominal approaches for fluoroscopy-guided percutaneous gastrostomy tube (G-tube) placement.METHODS:Following institutional review board approval, all G-tubes at two academic hospitals (January 2014 to May 2015) were reviewed retrospectively. Retrograde approach was used at Hospital 1 and both antegrade and retrograde approaches were used at Hospital 2. Chart review determined type of anesthesia used during placement, dose of radiation used, fluoroscopy time, procedure time, medical history, and complications.RESULTS:A total of 149 patients (64 women, 85 men; mean age, 64.4±1.3 years) underwent G-tube placement, including 93 (62%) placed via the retrograde transabdominal approach and 56 (38%) placed via the antegrade transoral approach. Retrograde placement entailed fewer anesthesiology consultations (P < 0.001), less overall procedure time (P = 0.023), and less fluoroscopy time (P < 0.001). A comparison of approaches for placement within the same hospital demonstrated that the retrograde approach led to significantly reduced radiation dose (P = 0.022). There were no differences in minor complication rates (13%–19%; P = 0.430), or major complication rates 6%–7%; P = 0.871) between the two techniques.CONCLUSION:G-tube placement using the retrograde transabdominal approach is associated with less fluoroscopy time, procedure time, radiation exposure, and need for anesthesiology consultation with similar safety profile compared with the antegrade transoral approach. Additionally, it is hypothesized that decreased procedure time and anesthesiology consultation using the transoral approach are likely associated with reduced cost

    Radon backgrounds in the DEAP-1 liquid-argon-based Dark Matter detector

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    The DEAP-1 \SI{7}{kg} single phase liquid argon scintillation detector was operated underground at SNOLAB in order to test the techniques and measure the backgrounds inherent to single phase detection, in support of the \mbox{DEAP-3600} Dark Matter detector. Backgrounds in DEAP are controlled through material selection, construction techniques, pulse shape discrimination and event reconstruction. This report details the analysis of background events observed in three iterations of the DEAP-1 detector, and the measures taken to reduce them. The 222^{222}Rn decay rate in the liquid argon was measured to be between 16 and \SI{26}{\micro\becquerel\per\kilogram}. We found that the background spectrum near the region of interest for Dark Matter detection in the DEAP-1 detector can be described considering events from three sources: radon daughters decaying on the surface of the active volume, the expected rate of electromagnetic events misidentified as nuclear recoils due to inefficiencies in the pulse shape discrimination, and leakage of events from outside the fiducial volume due to imperfect position reconstruction. These backgrounds statistically account for all observed events, and they will be strongly reduced in the DEAP-3600 detector due to its higher light yield and simpler geometry

    Dementia Wristband Report

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    This research project explored the use of new wearable and mobile technologies to support independent living and social interactions in the community for people living with dementia and their carers, more safely and for longer. The three key aims of the project were to: • Assess the potential acceptability, and usability of a mobile phone App and wearable wristband solution • Test the use of the technological in the everyday life contexts • Evaluate the usability and utility of a mobile phone App and digital wristband to reduce social isolation and improve health outcomes The research project had two stages: Stage 1 - Acceptability, utility and usability of the devices This stage of the project focused on developing initial understandings of the ways in which the proposed technological solutions work and potentially meet the needs of people living with dementia and their carers. This was achieved through: - Technology testing by the project team members. This gave the team a better understanding of the device used in the project. - Interviews with people with dementia and their carers, and with health and social care professionals. The interviews explored whether participants were receptive to, and what they thought about, the proposed solutions. Any concerns they had about the tracking technology in general or about the technology used in the project were also examined. Stage 2: Real world testing of the wristbands and smartphone App Research participant’s trialled the technology, as part of their everyday lives, for up to three months. During this period the research team worked closely with them to provide training and technological support and used a multi-method data collection focused on semi-structured interviews and observation to capture their experiences of using the technology. The participants living with dementia and their carers were given the opportunity to choose the technology that best suits them, either a wristbands or a smartphone application. Key findings In summary, through the interviews and focus groups and real world technology testing the research team and SME partners found there are issues around: - the use of technology for people living with dementia and their carers – for some people it was seen as a real benefit, others did not want to engage with the technology or have others know where they were. - education, information and support for people living with dementia and their carers to use new technologies; even when delivered via familiar technologies this can be challenging and needs support and time - support for family/other carers who are key to the support of mobile and wearable technologies. - support for people who do not have a local or remote family carer who can support the use of new technologies needs to be considered. - current GPS technologies not being accurate as a stand alone way of finding someone who may be lost or needing support. - safeguarding – which needs to take an holistic approach and include more traditional and ‘paper based’ safeguarding systems such as the Herbert protocol, - emerging and new technologies, which are developing constantly but a national approach is still missing; - the challenges for unpaid carers and people living with dementia to around exploring options around new technologies and deciding what are the best/cost effective options for their situations. - wearable and mobile technologies which can support people to be more independent in the community, but the technologies need to be: introduced early; affordable and be more easily supported by family and professional care givers as appropriate

    Improving Photoelectron Counting and Particle Identification in Scintillation Detectors with Bayesian Techniques

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    Many current and future dark matter and neutrino detectors are designed to measure scintillation light with a large array of photomultiplier tubes (PMTs). The energy resolution and particle identification capabilities of these detectors depend in part on the ability to accurately identify individual photoelectrons in PMT waveforms despite large variability in pulse amplitudes and pulse pileup. We describe a Bayesian technique that can identify the times of individual photoelectrons in a sampled PMT waveform without deconvolution, even when pileup is present. To demonstrate the technique, we apply it to the general problem of particle identification in single-phase liquid argon dark matter detectors. Using the output of the Bayesian photoelectron counting algorithm described in this paper, we construct several test statistics for rejection of backgrounds for dark matter searches in argon. Compared to simpler methods based on either observed charge or peak finding, the photoelectron counting technique improves both energy resolution and particle identification of low energy events in calibration data from the DEAP-1 detector and simulation of the larger MiniCLEAN dark matter detector.Comment: 16 pages, 16 figure

    Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy beta and nuclear recoils in liquid argon with DEAP-1

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    The DEAP-1 low-background liquid argon detector was used to measure scintillation pulse shapes of electron and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination (PSD) down to an electron-equivalent energy of 20 keV. In the surface dataset using a triple-coincidence tag we found the fraction of beta events that are misidentified as nuclear recoils to be <1.4×107<1.4\times 10^{-7} (90% C.L.) for energies between 43-86 keVee and for a nuclear recoil acceptance of at least 90%, with 4% systematic uncertainty on the absolute energy scale. The discrimination measurement on surface was limited by nuclear recoils induced by cosmic-ray generated neutrons. This was improved by moving the detector to the SNOLAB underground laboratory, where the reduced background rate allowed the same measurement with only a double-coincidence tag. The combined data set contains 1.23×1081.23\times10^8 events. One of those, in the underground data set, is in the nuclear-recoil region of interest. Taking into account the expected background of 0.48 events coming from random pileup, the resulting upper limit on the electronic recoil contamination is <2.7×108<2.7\times10^{-8} (90% C.L.) between 44-89 keVee and for a nuclear recoil acceptance of at least 90%, with 6% systematic uncertainty on the absolute energy scale. We developed a general mathematical framework to describe PSD parameter distributions and used it to build an analytical model of the distributions observed in DEAP-1. Using this model, we project a misidentification fraction of approx. 101010^{-10} for an electron-equivalent energy threshold of 15 keV for a detector with 8 PE/keVee light yield. This reduction enables a search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of 104610^{-46} cm2^2, assuming negligible contribution from nuclear recoil backgrounds.Comment: Accepted for publication in Astroparticle Physic

    In-situ characterization of the Hamamatsu R5912-HQE photomultiplier tubes used in the DEAP-3600 experiment

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    The Hamamatsu R5912-HQE photomultiplier-tube (PMT) is a novel high-quantum efficiency PMT. It is currently used in the DEAP-3600 dark matter detector and is of significant interest for future dark matter and neutrino experiments where high signal yields are needed. We report on the methods developed for in-situ characterization and monitoring of DEAP's 255 R5912-HQE PMTs. This includes a detailed discussion of typical measured single-photoelectron charge distributions, correlated noise (afterpulsing), dark noise, double, and late pulsing characteristics. The characterization is performed during the detector commissioning phase using laser light injected through a light diffusing sphere and during normal detector operation using LED light injected through optical fibres
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