152 research outputs found

    A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner

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    The design and operation of a receive-only liquid nitrogen (LN2)-cooled coil and cryostat suitable for medical imaging on a 3-T whole-body magnetic resonance scanner is presented. The coil size, optimized for murine imaging, was determined by using electromagnetic (EM) simulations. This process is therefore easier and more cost effective than building a range of coils. A nonmagnetic cryostat suitable for small-animal imaging was developed having good vacuum and cryogenic temperature performance. The LN2-cooled probe had an active detuning circuit allowing the use with the scanner's built-in body coil. External tuning and matching was adopted to allow for changes to the coil due to temperature and loading. The performance of the probe was evaluated by comparison of signal-to-noise ratio (SNR) with the same radio-frequency RF) coil operating at room temperature (RT). The performance of the RF coil at RT was also benchmarked against a commercial surface coil with a similar dimension to ensure a fair SNR comparison. The cryogenic coil achieved a 1.6- to twofold SNR gain for several different medical imaging applications: For mouse-brain imaging, a 100-mu m resolution was achieved in an imaging time of 3.5 min with an SNR of 25-40, revealing fine anatomical details unseen at lower resolutions for the same time. For heavier loading conditions, such as imaging of the hind legs and liver, the SNR enhancement was slightly reduced to 1.6-fold. The observed SNR was in good agreement with the expected SNR gain correlated with the loaded-quality factor of RF coils from the EM simulations. With the aid of this end-user-friendly and economically attractive cryogenic RF coil, the enhanced SNR available can be used to improve resolution or reduce the duration of individual scans in a number of biomedical applications

    Hill of Banchory Geothermal Energy Project Feasibility Study Report

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    This feasibility study explored the potential for a deep geothermal heat project at Hill of Banchory, Aberdeenshire. The geology of the Hill of Fare, to the north of Banchory, gives cause to believe it has good geothermal potential, while the Hill of Banchory heat network, situated on the northern side of the town, offers a ready-made heat customer. The partners in the consortium consisted of academics and developers with relevant expertise in deep geothermal energy, heat networks, and financial analysis, together with representatives of local Government. They conducted geological fieldwork around the Hill of Fare, engaged with local residents to establish their attitudes to geothermal energy, and built business models to predict the conditions under which the heat network at Hill of Banchory would be commercial if it utilised heat from the proposed geothermal well. They also estimated the potential carbon emission reductions that could be achieved by using deep geothermal energy, both at Hill of Banchory and more widely

    Thermochronology of South America passive margin between Uruguay and southern Brazil : A lengthy and complex cooling history based on (U–Th)/ He and fission tracks

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    The authors gratefully acknowledge the support from Shell Brasil through the “BG05: UoA-UFRGS-SWB Sedimentary Systems” project at UFRGS and UoA, and the strategic importance of the support given by ANP through the R&D levy regulation. J.P. Machado thanks the CNPq (SWE 204254/2017–5) for the exchange period at the University of Aberdeen, and A.R. Jelinek also thanks the support from CNPq (Project 303184/2017–5). We are grateful for the helpful and constructive reviews from Mathias Hueck, Mauricio Parra and an anonymous reviewer, that greatly improved this manuscript.Peer reviewedPostprin

    Feasibility of an online intervention (STAK-D) to promote physical activity in children with type 1 diabetes: protocol for a randomised controlled trial

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    Background: Regular physical activity has important health benefits for children with type 1 diabetes mellitus (T1DM), yet children and their parents face barriers to participation such as lack of self-efficacy or concerns around hypoglycaemia. Multimedia interventions are useful for educating children about their health and demonstrate potential to improve children’s health-related self-efficacy, but few paediatric clinics offer web-based resources as part of routine care. The Steps to Active Kids with Diabetes (STAK-D) programme is an online intervention grounded in psychological theory (social cognitive theory) and informed by extensive preliminary research. The aim of the programme is to encourage and support safe engagement with physical activity for children with T1DM. The aim of this research is to explore the feasibility of delivering the STAK-D programme to children aged 9–12 years with T1DM, and to assess the feasibility of further research to demonstrate its clinical and cost-effectiveness. Methods: Up to 50 children aged 9–12 years with T1DM and their parents will be recruited from two paediatric diabetes clinics in the UK. Child-parent dyads randomised to the intervention group will have access to the intervention website (STAK-D) and a wrist-worn activity monitor for 6 months. The feasibility of intervention and further research will be assessed by rate of recruitment, adherence, retention, data completion and adverse events. Qualitative interviews will be undertaken with a subsample of children and parents (up to 25 dyads) and health care professionals (up to 10). Health outcomes and the feasibility of outcome measurement tools will be assessed. These include self-efficacy (CSAPPA), objective physical activity, self-reported physical activity (PAQ), fear of hypoglycaemia (CHFS; PHFS), glycaemic control (HbA1c), insulin dose, Body Mass Index (BMI), health related quality of life (CHU9D; CHQ-PF28), health service use and patient-clinician communication. Assessments will be taken at baseline (T0), 8 weeks (T1) and at 6-month follow-up (T2). Discussion: The goal of this feasibility trial is to assess the delivery of STAK-D to promote physical activity among children with T1DM, and to assess the potential for further, definitive research to demonstrate its effectiveness. Results will provide the information necessary to design a larger randomised controlled trial and maximise the recruitment rate, intervention delivery and trial retention

    Chronic disease, risk factors and disability in adults aged 50 and above living with and without HIV: findings from the Wellbeing of Older People Study in Uganda.

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    BACKGROUND: Data on the prevalence of chronic conditions, their risk factors, and their associations with disability in older people living with and without HIV are scarce in sub-Saharan Africa. OBJECTIVES: In older people living with and without HIV in sub-Saharan Africa: 1) to describe the prevalence of chronic conditions and their risk factors and 2) to draw attention to associations between chronic conditions and disability. METHODS: Cross-sectional individual-level survey data from people aged 50 years and over living with and without HIV were analyzed from three study sites in Uganda. Diagnoses of chronic conditions were made through self-report, and disability was determined using the WHO Disability Assessment Schedule (WHODAS). We used ordered logistic regression and calculated predicted probabilities to show differences in the prevalence of multiple chronic conditions across HIV status, age groups, and locality. We used linear regression to determine associations between chronic conditions and the WHODAS. RESULTS: In total, 471 participants were surveyed; about half the respondents were living with HIV. The prevalence of chronic obstructive pulmonary disease and eye problems (except for those aged 60-69 years) was higher in the HIV-positive participants and increased with age. The prevalence of diabetes and angina was higher in HIV-negative participants. The odds of having one or more compared with no chronic conditions were higher in women (OR 1.6, 95% CI 1.1-2.3) and in those aged 70 years and above (OR 2.1, 95% CI 1.2-3.6). Sleep problems (coefficient 14.2, 95% CI 7.3-21.0) and depression (coefficient 9.4, 95% CI 1.2-17.0) were strongly associated with higher disability scores. CONCLUSION: Chronic conditions are common in older adults and affect their functioning. Many of these conditions are not currently addressed by health services in Uganda. There is a need to revise health care policy and practice in Uganda to consider the health needs of older people, particularly as the numbers of people living into older age with HIV and other chronic conditions are increasing

    Ultrasonic Tag Recognition

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    Physical activity and exercise interventions for people with rare neurological disorders : a scoping review of systematic reviews

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    Abstract Background: People living with rare neurological conditions (RNCs) often face common physical, cognitive and psychological challenges that lead to reduced physical activity and associated deconditioning. Physical activity interventions are routinely utilised to address disease specific limitations with the intention of promoting participation in people with RNCs. This scoping review aimed to synthesise the body of evidence for such interventions as they are applied across a wide range of RNCs. Methods: We undertook a scoping review of systematic reviews of any type of physical activity and exercise interventions for adults with neuromuscular diseases, motor neurone disease, Huntington’s disease, progressive supranuclear palsy, multiple system atrophy, inherited ataxias and hereditary spastic paraplegia. The reviews were included if they reported at least one outcome that aimed to increase physical activity level at either the body structure/function, activity and/or participation levels. Results: Sixty-two articles were full-text screened of which 27 were included. Most studies involved interventions in people with neuromuscular diseases. No reviews of interventions in hereditary spastic paraparesis were identified. The majority of reviews included studies of structured exercise using outcome measures at the level of body function and functional activity. Interventions were grouped as: i) combined interventions; ii) muscle strength training; iii) respiratory training; iv) aerobic training. Frequency, intensity, time and type of structured exercise utilised varied considerably across studies. Most studies were methodologically limited by small sample sizes, variation in exercise dose and training duration.Conclusions: To date, primary attention has been given to structured exercise interventions, which have demonstrated to have a low to uncertain level of evidence. Novel approaches to implementing common interventions and modalities are needed to increase accessibility and engagement in physical activity irrespective of disease type. Further exploration is warranted to achieve consensus on outcome measures that reflect areas of importance and relevance to people with RNCs

    Insomnia in breast cancer : a prospective observational study

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    STUDY OBJECTIVES: Insomnia in cancer patients is prevalent, persistent and confers risk for physical and psychological disorder. We must better understand how insomnia develops in cancer patients and explore the main contributors to its chronicity so that insomnia management protocols can be integrated more effectively within cancer care. This study monitors the etiology of insomnia in breast cancer patients and identifies risk factors for its persistence. METHODS: 173 females with newly diagnosed, non-metastatic breast cancer were tracked from diagnosis for 12-months. Participants completed monthly sleep assessments using the Insomnia Severity Index (ISI) and 3-monthly health-related quality-of-life assessments using the European Organisation for Research and Treatment of Cancer - Breast (EORTC QLQ-C30-BR23) scale. Clinical data on disease status and treatment regimens were also assessed. RESULTS: Prior to diagnosis, 25% of participants reported sleep disturbance, including 8% with insomnia syndrome (IS). Prevalence increased at cancer diagnosis to 46% (18% IS) and remained stable thereafter at around 50% (21% IS). We also explored sleep status transitions. The most common pattern was to remain a good sleeper (34%-49%) or to persist with insomnia (23%-46%). 77% of good sleepers developed insomnia during the 12-month period and 54% went into insomnia remission. Chemotherapy (odds ratio=0·08, 95% ci 0·02-0·29, p<·001) and pre-diagnosis ISI scores (odds ratio=1·13/unit increase in pre-diagnosis sleep score, 95% ci 1·05-1·21, p=·001) were identified as the main risk factors for persistent insomnia. CONCLUSIONS: These data advance our understanding of insomnia etiology in cancer patients and help identify those who should be prioritised for insomnia management protocols
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