25 research outputs found

    Plasma Polymerisation Using Helium Atmospheric-Pressure Plasma Jet with Heptylamine Monomer

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    Atmospheric-pressure plasma jets can be used to modify surfaces in a spatially-defined manner. Operating these jets in air is an efficient surface modification tool, however the resulting surface chemistries are limited by the plasma gases. In this study we demonstrate that plasma polymerisation with heptylamine on polystyrene surfaces, using an atmospheric pressure plasma jet, can enable mammalian cell attachment and growth. Importantly, the addition of the heptylamine monomer, in a helium carrier-gas, altered the spatially-defined treatment area in comparison to treatment with a helium plasma alone

    The Shark Assemblage at French Frigate Shoals Atoll, Hawai‘i: Species Composition, Abundance and Habitat Use

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    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao Mh ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289–1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Characterisation of an asymmetric AGATA detector

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    The Advanced GAmma Tracking Array, AGATA, is a European project aimed at constructing a next-generation gamma-ray spectrometer for nuclear structure studies. The completed array will consist of a 47f shell of 180 highly segmented HPGe detectors arranged into 60 triple clusters. The array will be instrumented with state of the art digital electronics, and will apply Pulse Shape Analysis (PSA) and Gamma-Ray Tracking (GRT) algorithms to achieve high efficiency while maintaining the excellent peak-to-total ratio of current escape-suppressed spectrometers. Vital to the successful application of PSA is the establishment of a pulse shape database describing the signal shape produced by interactions at each point in the detectors volume. Electric field simulations have been developed within the AGATA collaboration to provide this signal basis but it is necessary that they are tested against experimental measurements. Characterisation measurements were performed on asymmetric AGATA capsule C00l using the Liverpool scanning system and state-of-the-art digital electronics. A highly collimated beam of 662ke V gamma rays was scanned across the detector and single and coincident trigger modes were used to measure the response due to gamma rays interacting at precisely determined points within the detector. These signals were then compared with signals produced by the electric field simulations Multi Geometry Simulation (MGS) and JAVA AGATA Signal Simulation (JASS) and an assessment made of their performance. Position resolutions of 7.8mm and 8.4mm have been measured when performing PSA with MGS and JASS respectively. These values are larger than expected and an attempt has been made to understand the reasons for this. In addition, measurements have been carried out to assess the electronics response function of the detector and associated electronics. The results of these characterisation measurements will be used by the AGATA collaboaration to refine the online PSA and GRT algorithms used with the array.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Plasma Polymerisation Using Helium Atmospheric-Pressure Plasma Jet with Heptylamine Monomer

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    This data set contains the raw data used to produce our paper "Plasma Polymerisation Using Helium Atmospheric-Pressure Plasma Jet with Heptylamine Monomer" published in Plasma Processes and Polymers. The data contains water contact angle, XPS, AFM, and cell culture data. Atmospheric-pressure plasma jets can be used to modify surfaces in a spatially-defined manner. Operating these jets in air is an efficient surface modification tool, however the resulting surface chemistries are limited by the plasma gases. In this study we demonstrate that plasma polymerisation with heptylamine on polystyrene surfaces, using an atmospheric pressure plasma jet, can enable mammalian cell attachment and growth. In addition, the plasma polymerisation with heptylamine, in a helium carrier-gas, altered the spatially-defined treatment area in comparison to treatment with a helium plasma alone
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