111 research outputs found

    Reduced dimension modeling of leading edge turbulent interaction noise

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    A computational aeroacoustics approach is used to model the effects of real airfoil geometry on leading edge turbulent interaction noise for symmetric airfoils at zero angle of attack. For the first time, one-component (transverse), two-component (transverse and streamwise), and three-component (transverse, streamwise, and spanwise) synthesized turbulent disturbances are modeled instead of single frequency transverse gusts, which previous computational studies of leading edge noise have been confined to. The effects of the inclusion of streamwise and spanwise disturbances on the noise are assessed, and it is shown that accurate noise predictions for symmetric airfoils can be made by modeling only the transverse disturbances, which reduces the computational expense of simulations. Additionally, the two-component turbulent synthesis method is used to model the effects of airfoil thickness on the noise for thicknesses ranging from 2% to 12%. By using sufficient airfoil thicknesses to show trends, it is found that airfoil thickness will reduce the noise at high frequency, and that the sound power P will reduce linearly with increasing airfoil thickness

    A simple, low-cost conductive composite material for 3D printing of electronic sensors

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    3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept prototypes (‘rapid prototyping’) before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term ‘carbomorph’ and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes

    The discovery of potent, selective, and reversible inhibitors of the house dust mite peptidase allergen Der p 1: an innovative approach to the treatment of allergic asthma.

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    Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma

    Community perceptions of health and chronic disease in South Indian rural transitional communities: A qualitative study

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    BACKGROUND: Chronic diseases are now the leading cause of death and disability worldwide; this epidemic has been linked to rapid economic growth and urbanisation in developing countries. Understanding how characteristics of the physical, social, and economic environment affect behaviour in the light of these changes is key to identifying successful interventions to mitigate chronic disease risk. DESIGN: We undertook a qualitative study consisting of nine focus group discussions (FGDs) (n=57) in five villages in rural Andhra Pradesh, South India, to understand people's perceptions of community development and urbanisation in relation to chronic disease in rural transitional communities. Specifically, we sought to understand perceptions of change linked to diet, physical activity, and pollution (because these exposures are most relevant to chronic diseases), with the aim of defining future interventions. The transcripts were analysed thematically. RESULTS: Participants believed their communities were currently less healthy, more polluted, less physically active, and had poorer access to nutritious food and shorter life expectancies than previously. There were contradictory perceptions of the effects of urbanisation on health within and between individuals; several of the participants felt their quality of life had been reduced. CONCLUSIONS: In the present study, residents viewed change and development within their villages as an inevitable and largely positive process but with some negative health consequences. Understanding how these changes are affecting populations in transitional rural areas and how people relate to their environment may be useful to guide community planning for health. Measures to educate and empower people to make healthy choices within their community may help reduce the spread of chronic disease risk factors in future years

    Construct validation of the Health Utilities Index and the Child Health Questionnaire in children undergoing cancer chemotherapy

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    The objective of this study was to evaluate the construct validity of two questionnaire-based measures of health-related quality of life (HRQL) in children undergoing cancer chemotherapy: the Health Utilities Index (HUI) and the Child Health Questionnaire (CHQ). Subjects were children hospitalised for chemotherapy. To examine construct validity: (1) a priori expected relations between CHQ concepts and HUI attributes were examined; (2) HUI and CHQ summary scores were compared to visual analogue scale (VAS) scores. Ease of completion was rated using a 5-point categorical scale and completion time was recorded. A total of 36 subjects were included. The maximum score was seen in 15 (47%) of HUI3 assessments. As predicted, CHQ body pain was moderately correlated with HUI3 pain (r=0.51), CHQ physical functioning was moderately correlated with HUI2 mobility (r=0.58) and CHQ mental health was moderately correlated with HUI2 emotion (r=0.53). Only the CHQ psychosocial subscale (and not HUI) was correlated with VAS (r=0.44). The CHQ and the HUI were both easy to use. The HUI questionnaires required less time to complete (mean=3.1, s.d.=1 min) compared with CHQ (mean=13.1, s.d.=3.4 min, P<0.0001). In conclusion, HUI and CHQ demonstrated construct validity in children undergoing cancer chemotherapy. The Health Utilities Index is subject to a ceiling effect whereas CHQ requires more time to complete

    Operando ultrasonic monitoring of lithium-ion battery temperature and behaviour at different cycling rates and under drive cycle conditions

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    Effective diagnostic techniques for Li-ion batteries are vital to ensure that they operate in the required voltage and temperature window to prevent premature degradation and failure. Ultrasonic analysis has been gaining significant attention as a low cost, fast, non-destructive, operando technique for assessing the state-of-charge and state-of-health of Li-ion batteries. Thus far, the majority of studies have focused on a single C-rate at relatively low charge and discharge currents, and as such the relationship between the changing acoustic signal and C-rate is not well understood. In this work, the effect of cell temperature on the acoustic signal is studied and shown to have a strong correlation with the signal's time-of-flight. This correlation allows for the cell temperature to be inferred using ultrasound and to compensate for these effects to accurately predict the state-of-charge regardless of the C-rate at which the cell is being cycled. Ultrasonic state-of-charge monitoring of a cell during a drive cycle illustrates the suitability of this technique to be applied in real-world situations, an important step in the implementation of this technique in battery management systems with the potential to improve pack safety, performance, and efficiency

    AD51B in Familial Breast Cancer

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    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C&gt;T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

    How well do services for young people with long term conditions deliver features proposed to improve transition?

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    BACKGROUND: For young people with long-term conditions, transition from child to adult-oriented health services is a critical period which, if not managed well, may lead to poor outcomes. There are features of transition services which guidance and research suggest improve outcomes. We studied nine such features, calling them \u27proposed beneficial features\u27: age-banded clinic; meet adult team before transfer; promotion of health self-efficacy; written transition plan; appropriate parent involvement; key worker; coordinated team; holistic life-skills training; transition manager for clinical team. We aimed to describe the extent to which service providers offer these nine features, and to compare this with young people\u27s reported experience of them. METHODS: A longitudinal, mixed methods study followed 374 young people as their care moved from child to adult health services. Participants had type 1 diabetes, cerebral palsy or autism spectrum disorder with additional mental health difficulties. Data are reported from the first two visits, one year apart. RESULTS: Three hundred four (81.3%) of the young people took part in the second visit (128 with diabetes, 91 with autism, 85 with cerebral palsy). Overall, the nine proposed beneficial features of transition services were poorly provided. Fewer than half of services stated they provided an age-banded clinic, written transition plan, transition manager for clinical team, a protocol for promotion of health self-efficacy, or holistic life-skills training. To varying degrees, young people reported that they had not experienced the features which services said they provided. For instance, the agreement for written transition plan, holistic life-skills training and key worker, was 30, 43 and 49% respectively. Agreement was better for appropriate parent involvement, age-banded clinic, promotion of health self-efficacy and coordinated team at 77, 77, 80 and 69% respectively. Variation in the meaning of the features as experienced by young people and families was evident from qualitative interviews and observations. CONCLUSIONS: UK services provide only some of the nine proposed beneficial features for supporting healthcare transition of young people with long term conditions. Observational studies or trials which examine the influence of features of transition services on outcomes should ensure that the experiences of young people and families are captured, and not rely on service specifications
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