138 research outputs found

    A microfluidic atmospheric-pressure plasma reactor for water treatment

    Get PDF
    A dielectric barrier discharge microfluidic plasma reactor, operated at atmospheric pressure, was studied for its potential to treat organic contaminants in water. Microfluidic technology represents a compelling approach for plasma-based water treatment due to inherent characteristics such as a large surface-area-to-volume ratio and flow control, in inexpensive and portable devices. The microfluidic device in this work incorporated a dielectric barrier discharge generated in a continuous gas flow stream of a two-phase annular flow regime in the microchannels of the device. Methylene blue in solution was used to investigate plasma induced degradation of dissolved organic compounds within the microfluidic device. The relative degradation rates of methylene blue were influenced by the residence time of the sample solution in the discharge zone, type of gas applied, channel depth and flow rate. Increasing the residence time inside the plasma region led to higher levels of degradation. Oxygen was found to be the most effective gas, with the spectra obtained using Liquid Chromatography-Mass Spectroscopy indicating the most significant degradation. By reducing the channel depth from 100 to 50 ”m, the best results were obtained, achieving a greater than 97% level of methylene blue degradation. The microfluidic system presented here demonstrates proof-of-concept that plasma technology can be utilised as an advanced oxidation process for water treatment, with the potential to eliminate water treatment consumables such as filters and disinfectants

    Maternal and fetal cardiometabolic recovery following ultrasound-guided high-intensity focused ultrasound placental vascular occlusion.

    Get PDF
    High-intensity focused ultrasound (HIFU) is a non-invasive method of selective placental vascular occlusion, providing a potential therapy for conditions such as twin-twin transfusion syndrome. In order to translate this technique into human studies, evidence of prolonged fetal recovery and maintenance of a healthy fetal physiology following exposure to HIFU is essential. At 116 ± 2 days gestation, 12 pregnant ewes were assigned to control ( n = 6) or HIFU vascular occlusion ( n = 6) groups and anaesthetized. Placental blood vessels were identified using colour Doppler ultrasound; HIFU-mediated vascular occlusion was performed through intact maternal skin (1.66 MHz, 5 s duration, in situ ISPTA 1.8-3.9 kW cm-2). Unidentifiable colour Doppler signals in targeted vessels following HIFU exposure denoted successful occlusion. Ewes and fetuses were then surgically instrumented with vascular catheters and transonic flow probes and recovered from anaesthesia. A custom-made wireless data acquisition system, which records continuous maternal and fetal cardiovascular data, and daily blood sampling were used to assess wellbeing for 20 days, followed by post-mortem examination. Based on a comparison of pre- and post-treatment colour Doppler imaging, 100% (36/36) of placental vessels were occluded following HIFU, and occlusion persisted for 20 days. All fetuses survived. No differences in maternal or fetal blood pressure, heart rate, heart rate variability, metabolic status or oxygenation were observed between treatment groups. There was evidence of normal fetal maturation and no evidence of chronic fetal stress. There were no maternal injuries and no placental vascular haemorrhage. There was both a uterine and fetal burn, which did not result in any obstetric or fetal complications. This study demonstrates normal long-term recovery of fetal sheep from exposure to HIFU-mediated placental vascular occlusion and underlines the potential of HIFU as a potential non-invasive therapy in human pregnancy

    Parents and GPs’ understandings and beliefs about food allergy testing in children with eczema:qualitative interview study within the Trial of Eczema allergy Screening Tests (TEST) feasibility trial

    Get PDF
    Aim To explore parent and general practitioner (GP) understanding and beliefs about food allergy testing for children with eczema.Design and setting Qualitative interview study in UK primary care within the Trial of Eczema allergy Screening Tests feasibility trial.Participants Semi-structured interviews with parents of children with eczema taking part in the feasibility study and GPs at practices hosting the study.Results 21 parents and 11 GPs were interviewed. Parents discussed a range of potential causes for eczema, including a role for food allergy. They believed allergy testing to be beneficial as it could potentially identify a cure or help reduce symptoms and they found negative tests reassuring, suggesting to them that no dietary changes were needed. GPs reported limited experience and uncertainty regarding food allergy in children with eczema. While some GPs believed referral for allergy testing could be appropriate, most were unclear about its utility. They thought it should be reserved for children with severe eczema or complex problems but wanted more information to advise parents and help guide decision making.Conclusions Parents’ motivations for allergy testing are driven by the desire to improve their child’s condition and exclude food allergy as a possible cause of symptoms. GPs are uncertain about the role of allergy testing and want more information about its usefulness to support parents and help inform decision making.Trial registration number ISRCTN15397185

    Choice of Moisturiser for Eczema Treatment (COMET):feasibility study of a randomised controlled parallel group trial in children recruited from primary care

    Get PDF
    OBJECTIVES: To determine the feasibility of a randomised controlled trial of ‘leave on’ emollients for children with eczema. DESIGN: Single-centre, pragmatic, 4-arm, observer-blinded, parallel, randomised feasibility trial. SETTING: General practices in the UK. PARTICIPANTS: Children with eczema aged 1 month to <5 years. OUTCOME MEASURES: Primary outcome—proportion of parents who reported use of the allocated study emollient every day for the duration of follow-up (12 weeks). Other feasibility outcomes—participant recruitment and retention, data collection and completeness and blinding of observers to allocation. INTERVENTIONS: Aveeno lotion, Diprobase cream, Doublebase gel, Hydromol ointment. RESULTS: 197 children were recruited—107 by self-referral (mainly via practice mail-outs) and 90 by inconsultation (clinician consenting and randomising) pathways. Participants recruited inconsultation were younger, had more severe Patient-Oriented Eczema Measure scores and were more likely to withdraw than self-referrals. Parents of 20 (10%) of all the randomised participants reported using the allocated emollient daily for 84 days. The use of other non-study emollients was common. Completeness of data collected by parent-held daily diaries and at monthly study visits was good. Daily diaries were liked (81%) but mainly completed on paper rather than via electronic (‘app’) form. Major costs drivers were general practitioner consultations and eczema-related prescriptions. Observer unblinding was infrequent, and occurred at the baseline or first follow-up visit through accidental disclosure. CONCLUSIONS: It is feasible in a primary care setting to recruit and randomise young children with eczema to emollients, follow them up and collect relevant trial data, while keeping observers blinded to their allocation. However, reported use of emollients (study and others) has design implications for future trials. TRIAL REGISTRATION NUMBER: ISRCTN21828118/EudraCT2013-003001-26

    Altered Cardiovascular Defense to Hypotensive Stress in the Chronically Hypoxic Fetus.

    Get PDF
    The hypoxic fetus is at greater risk of cardiovascular demise during a challenge, but the reasons behind this are unknown. Clinically, progress has been hampered by the inability to study the human fetus non-invasively for long period of gestation. Using experimental animals, there has also been an inability to induce gestational hypoxia while recording fetal cardiovascular function as the hypoxic pregnancy is occurring. We use novel technology in sheep pregnancy that combines induction of controlled chronic hypoxia with simultaneous, wireless recording of blood pressure and blood flow signals from the fetus. Here, we investigated the cardiovascular defense of the hypoxic fetus to superimposed acute hypotension. Pregnant ewes carrying singleton fetuses surgically prepared with catheters and flow probes were randomly exposed to normoxia or chronic hypoxia from 121±1 days of gestation (term ≈145 days). After 10 days of exposure, fetuses were subjected to acute hypotension via fetal nitroprusside intravenous infusion. Underlying in vivo mechanisms were explored by (1) analyzing fetal cardiac and peripheral vasomotor baroreflex function; (2) measuring the fetal plasma catecholamines; and (3) establishing fetal femoral vasoconstrictor responses to the α1-adrenergic agonist phenylephrine. Relative to controls, chronically hypoxic fetal sheep had reversed cardiac and impaired vasomotor baroreflex function, despite similar noradrenaline and greater adrenaline increments in plasma during hypotension. Chronic hypoxia markedly diminished the fetal vasopressor responses to phenylephrine. Therefore, we show that the chronically hypoxic fetus displays markedly different cardiovascular responses to acute hypotension, providing in vivo evidence of mechanisms linking its greater susceptibility to superimposed stress.The British Heart Foundatio

    Rapid antibiotic susceptibility testing using resazurin bulk modified screen-printed electrochemical sensing platforms

    Get PDF
    Urinary tract infections (UTIs) are one of the most common types of bacterial infection. UTIs can be associated with multidrug resistant bacteria and current methods of determining an effective antibiotic for UTIs can take up to 48 hours, which increases the chances of a negative prognosis for the patient. In this paper we report for the first time, the fabrication of resazurin bulk modified screen-printed macroelectrodes (R-SPEs) demonstrating them to be effective platforms for the electrochemical detection of antibiotic susceptibility in complicated UTIs. Using differential pulse voltammetry (DPV), resazurin was able to be detected down to 15.6 ÎŒM. R-SPEs were utilised to conduct antibiotic susceptibility testing (AST) of E. coli (ATCCÂź 25922) to the antibiotic gentamicin sulphate using DPV to detect the relative concentrations of resazurin between antibiotic treated bacteria, and bacteria without antibiotic treatment. Using R-SPEs, antibiotic susceptibility was determined after a total elapsed time of 90 minutes including the inoculation of the artificial urine, preincubation and testing time. The use of electrochemistry as a phenotypic means of identifying an effective antibiotic to treat a complicated UTI offers a rapid and accurate alternative to culture based methods for AST with R-SPEs offering an inexpensive and simpler alternative to other AST methods utilising electrochemical based approaches

    Are concentrations of pollutants in sharks, rays and skates (Elasmobranchii) a cause for concern? A systematic review

    Get PDF
    This review represents a comprehensive analysis on pollutants in elasmobranchs including meta-analysis on the most studied pollutants: mercury, cadmium, PCBs and DDTs, in muscle and liver tissue. Elasmobranchs are particularly vulnerable to pollutant exposure which may pose a risk to the organism as well as humans that consume elasmobranch products. The highest concentrations of pollutants were found in sharks occupying top trophic levels (Carcharhiniformes and Lamniformes). A human health risk assessment identified that children and adults consuming shark once a week are exposed to over three times more mercury than is recommended by the US EPA. This poses a risk to local fishing communities and international consumers of shark-based products, as well as those subject to the widespread mislabelling of elasmobranch products. Wider screening studies are recommended to determine the risk to elasmobranchs from emerging pollutants and more robust studies are recommended to assess the risks to human health

    Factors affecting the survival of harbor ( Phoca vitulina ) and gray seal ( Halichoerus grypus ) juveniles admitted for rehabilitation in the UK and Ireland

    Get PDF
    From Wiley via Jisc Publications RouterHistory: received 2021-06-15, accepted 2022-09-13, pub-electronic 2022-10-14Article version: VoRPublication status: PublishedAbstract: The UK shores are home to approximately 40% of the world's population of gray seals (Halichoerus grypus) and 40% of Europe's harbor seals (Phoca vitulina). Stranded juvenile seals of both species are frequently rescued and admitted for rehabilitation. This study investigates the causes of P. vitulina and H. grypus admittance to rehabilitation centers in the UK and Ireland and identifies factors that can affect juvenile seal survival. Rehabilitation records for 1,435 P. vitulina and 2,691 H. grypus were used from five rehabilitation centers from 1988 through 2020. The most common nonexclusive reasons for seal admission to rehabilitation centers included malnourishment (37%), injuries (37%), maternal abandonment (15%), lethargy (12%), and parasite infections (8%). A mixed effects logistic regression model showed that H. grypus had 4.55 times higher survival odds than P. vitulina and that the odds of survival to release multiplied by 1.07 for every kilogram over their age‐predicted weight. This weight‐dependent survival could be attributed to the importance of fat in thermoregulation, hydration, and buoyancy during foraging. We recommend that seal rehabilitators pay special attention to the weight of admitted juvenile seals during triage and treatment to enhance their odds of survival and consequent release to the wild

    Factors affecting the survival of harbor (Phoca vitulina) and gray seal (Halichoerus grypus) juveniles admitted for rehabilitation in the UK and Ireland

    Get PDF
    The UK shores are home to approximately 40% of the world's population of gray seals (Halichoerus grypus) and 40% of Europe's harbor seals (Phoca vitulina). Stranded juvenile seals of both species are frequently rescued and admitted for rehabilitation. This study investigates the causes of P. vitulina and H. grypus admittance to rehabilitation centers in the UK and Ireland and identifies factors that can affect juvenile seal survival. Rehabilitation records for 1,435 P. vitulina and 2,691 H. grypus were used from five rehabilitation centers from 1988 through 2020. The most common nonexclusive reasons for seal admission to rehabilitation centers included malnourishment (37%), injuries (37%), maternal abandonment (15%), lethargy (12%), and parasite infections (8%). A mixed effects logistic regression model showed that H. grypus had 4.55 times higher survival odds than P. vitulina and that the odds of survival to release multiplied by 1.07 for every kilogram over their age-predicted weight. This weight-dependent survival could be attributed to the importance of fat in thermoregulation, hydration, and buoyancy during foraging. We recommend that seal rehabilitators pay special attention to the weight of admitted juvenile seals during triage and treatment to enhance their odds of survival and consequent release to the wild
    • 

    corecore