52 research outputs found

    Structure and properties of rare earth metaphosphate glasses

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    SIGLEAvailable from British Library Document Supply Centre-DSC:DXN024364 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    An EXAFS study of rare-earth phosphate glasses in the vicinity of the metaphosphate composition

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    A study of rare-earth phosphate glasses, in the vicinity of the metaphosphate composition, has been undertaken at different temperatures using the extended X-ray absorption fine structure (EXAFS) facility at the Synchrotron Radiation Source, Daresbury Laboratory, UK. The metaphosphate-like glasses examined contained the rare-earth elements La, Sm. Eu and Gd as R3+ ions. The experiments were carried out at room temperature, 145 and 79 K. The data show that the first shell surrounding rare-earth ions contains only oxygen atoms at a mean distance of similar to 2.2-2.4 Angstrom. The 'Iantfianide contraction' is clearly observed, i.e., the R-O distance decreases with increasing atomic number. The observed R(-O) coordination numbers are in the range 5-7. A second correlation shell was found associated with phosphorus atoms around the central rare-earth atom (similar to 3.5 Angstrom), and another rare-earth:oxygen correlation was also identified (similar to 4 Angstrom). Static disorder dominates the Debye-Waller term, but thermal disorder is not negligible. Within the accuracy of the EXAFS data, no significant structural variations were observed over the temperature range studied. We conclude that the anomalous bulk properties are associated with either subtle structural features or primarily due to rare-earth ion Interactions

    Breast density notification: A systematic review of the impact on primary care practitioners

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    Background: In the last decade, there has been an unprecedented amount of advocacy and attention surrounding the issue of breast density (BD) in relation to mammography screening. It is largely unknown what impact notifying women of their BD has had on clinical practice for PCPs. This systematic review aimed to synthesize evidence from existing studies to understand the impact of BD notification on primary care practitioners\u27 (PCPs) knowledge, attitudes, and practice implications. Methods: Empirical studies were identified through relevant database searches (database inception to May 2020). Two authors evaluated the eligibility of studies, extracted and crosschecked data, and assessed the risk of bias. Results were synthesized in a narrative form. Results: Six studies of the 232 titles identified and screened were included. All studies were undertaken in the United States, with five conducted postlegislation in their respective states, and one study conducted in states that were both prelegislation and postlegislation. Five studies were quantitative, including four cross-sectional surveys, and one study was qualitative. Findings consistently demonstrated PCPs\u27 overall lack of knowledge about BD, low level of comfort in discussing and managing patients in relation to dense breasts, and limited consensus on the most appropriate approach for managing women with dense breasts, particularly in relation to supplemental screening. Conclusions: This review highlights important gaps in PCPs\u27 understanding of BD and confidence in having discussions with women about the implications of dense breasts. It identifies the need for high-quality research and the development of evidence-based guidelines to better support PCPs

    The impact of diabetes-related complications on preference-based measures of health-related quality of life in adults with Type I diabetes

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    Introduction: This study estimates health-related quality of life (HRQoL) or utility decrements associated with type 1 diabetes mellitus (T1DM) using data from a UK research programme on the Dose Adjustment For Normal Eating (DAFNE) education programme. Methods: A wide range of data was collected from 2,341 individuals who undertook a DAFNE course in 2009-12, at baseline and for two subsequent years. We use fixed and random effects linear models to generate utility estimates for T1DM using different instruments: EQ-5D, SF-6D and EQ-VAS. We show models with and without controls for HbA1c and depression, which may be endogenous (if, for example, there is reverse causality in operation). Results: We find strong evidence of an unobserved individual effect, suggesting the superiority of the fixed effects model. Depression shows the greatest decrement across all the models in the preferred fixed effects model. The fixed effects EQ-5D model also finds a significant decrement from retinopathy, BMI and HbA1c(%). Estimating a decrement using the fixed effects model is not possible for some conditions where there are few new cases. In the random effects model diabetic foot disease shows substantial utility decrements, yet these are not significant in the fixed effects models. Conclusion: Utility decrements have been calculated for a wide variety of health states in T1DM which can be used in economic analyses. However, despite the large dataset, the low incidence of several complications leads to uncertainty in calculating the utility weights. Depression and diabetic foot disease result in a substantial loss in HRQoL for patients with T1DM. HbA1c(%) appears to have an independent negative impact upon HRQoL, although concerns remain regarding the potential endogeneity of this variable

    Linking demand and supply factors in identifying cultural ecosystem services of urban green infrastructures:A review of European studies

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    Urban green infrastructure provides a number of cultural ecosystem services that are greatly appreciated by the public. In order to benefit from these services, actual contact with the respective ecosystem is often required. Furthermore, the type of services offered depend on the physical characteristics of the ecosystem. We conducted a review of publications dealing with demand or social factors such as user needs, preferences and values as well as spatially explicit supply or physical factors such as amount of green space, (bio)diversity, recreational infrastructure, etc. and linking demand and supply factors together. The aim was to provide an overview of this highly interdisciplinary research, to describe how these linkages are being made and to identify which factors significantly influence dependent variables such as levels of use, activities or health and well-being benefits. Commonly used methods were the combination of questionnaires with either on-site visual recording of elements or GIS data. Links between social and physical data were usually established either by using statistical tools or by overlaying different thematic maps. Compared to the large number of variables assessed in most studies, the significant effects in the end were relatively few, not consistent across the studies and largely dependent on the context they were seen in. Studies focused on aesthetic and recreational services, while spiritual, educational and inspirational services were not considered when creating links to spatially explicit ecological structures. We conclude that an improvement and harmonization of methodologies, cross-country studies and an expansion of this line of research to a wider range of services and more user groups could help clarify relationships and thereby increase applicability for urban management and planning.</p

    Effects of rare-earth co-doping on the local structure of rare-earth phosphate glasses using high and low energy X-ray diffraction

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    Rare-earth co-doping in inorganic materials has a long-held tradition of facilitating highly desirable optoelectronic properties for their application to the laser industry. This study concentrates specifically on rare-earth phosphate glasses, (R2O3)x(R'2O3)y(P2O5)1-(x+y), where (R, R') denotes (Ce, Er) or (La, Nd) co-doping and the total rare-earth composition corresponds to a range between metaphosphate, RP3O9, and ultraphosphate, RP5O14. Thereupon, the effects of rare-earth co-doping on the local structure are assessed at the atomic level. Pair-distribution function analysis of high-energy X-ray diffraction data (Qmax = 28 Ã…-1) is employed to make this assessment. Results reveal a stark structural invariance to rare-earth co-doping which bears testament to the open-framework and rigid nature of these glasses. A range of desirable attributes of these glasses unfold from this finding; in particular, a structural simplicity that will enable facile molecular engineering of rare-earth phosphate glasses with 'dial-up' lasing properties. When considered together with other factors, this finding also demonstrates additional prospects for these co-doped rare-earth phosphate glasses in nuclear waste storage applications. This study also reveals, for the first time, the ability to distinguish between P-O and PO bonding in these rare-earth phosphate glasses from X-ray diffraction data in a fully quantitative manner. Complementary analysis of high-energy X-ray diffraction data on single rare-earth phosphate glasses of similar rare-earth composition to the co-doped materials is also presented in this context. In a technical sense, all high-energy X-ray diffraction data on these glasses are compared with analogous low-energy diffraction data; their salient differences reveal distinct advantages of high-energy X-ray diffraction data for the study of amorphous materials

    Radiotherapy plus cisplatin or cetuximab in low-risk human papillomavirus-positive oropharyngeal cancer (De-ESCALaTE HPV):an open-label randomised controlled phase 3 trial

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    Background The incidence of human papillomavirus (HPV)-positive oropharyngeal cancer, a disease affecting younger patients, is rapidly increasing. Cetuximab, an epidermal growth factor receptor inhibitor, has been proposed for treatment de-escalation in this setting to reduce the toxicity of standard cisplatin treatment, but no randomised evidence exists for the efficacy of this strategy. Methods We did an open-label randomised controlled phase 3 trial at 32 head and neck treatment centres in Ireland, the Netherlands, and the UK, in patients aged 18 years or older with HPV-positive low-risk oropharyngeal cancer (non-smokers or lifetime smokers with a smoking history of <10 pack-years). Eligible patients were randomly assigned (1: 1) to receive, in addition to radiotherapy (70 Gy in 35 fractions), either intravenous cisplatin (100 mg/m(2) on days 1, 22, and 43 of radiotherapy) or intravenous cetuximab (400 mg/m(2) loading dose followed by seven weekly infusions of 250 mg/m(2)). The primary outcome was overall severe (grade 3-5) toxicity events at 24 months from the end of treatment. The primary outcome was assessed by intention-to-treat and per-protocol analyses. This trial is registered with the ISRCTN registry, number ISRCTN33522080. Findings Between Nov 12, 2012, and Oct 1, 2016, 334 patients were recruited (166 in the cisplatin group and 168 in the cetuximab group). Overall (acute and late) severe (grade 3-5) toxicity did not differ significantly between treatment groups at 24 months (mean number of events per patient 4.8 [95% CI 4.2-5.4] with cisplatin vs 4.8 [4.2-5.4] with cetuximab; p=0.98). At 24 months, overall all-grade toxicity did not differ significantly either (mean number of events per patient 29.2 [95% CI 27.3-31.0] with cisplatin vs 30.1 [28.3-31.9] with cetuximab; p=0.49). However, there was a significant difference between cisplatin and cetuximab in 2-year overall survival (97.5% vs 89.4%, hazard ratio 5.0 [95% CI 1.7-14.7]; p=0.001) and 2-year recurrence (6.0% vs 16.1%, 3.4 [1.6-7.2]; p=0.0007). Interpretation Compared with the standard cisplatin regimen, cetuximab showed no benefit in terms of reduced toxicity, but instead showed significant detriment in terms of tumour control. Cisplatin and radiotherapy should be used as the standard of care for HPV-positive low-risk patients who are able to tolerate cisplatin. Funding Cancer Research UK. Copyright (c) 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license

    Educational paper: Abusive Head Trauma Part I. Clinical aspects

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    Abusive Head Trauma (AHT) refers to the combination of findings formerly described as shaken baby syndrome. Although these findings can be caused by shaking, it has become clear that in many cases there may have been impact trauma as well. Therefore a less specific term has been adopted by the American Academy of Pediatrics. AHT is a relatively common cause of childhood neurotrauma with an estimated incidence of 14–40 cases per 100,000 children under the age of 1 year. About 15–23% of these children die within hours or days after the incident. Studies among AHT survivors demonstrate that approximately one-third of the children are severely disabled, one-third of them are moderately disabled and one-third have no or only mild symptoms. Other publications suggest that neurological problems can occur after a symptom-free interval and that half of these children have IQs below the 10th percentile. Clinical findings are depending on the definitions used, but AHT should be considered in all children with neurological signs and symptoms especially if no or only mild trauma is described. Subdural haematomas are the most reported finding. The only feature that has been identified discriminating AHT from accidental injury is apnoea. Conclusion: AHT should be approached with a structured approach, as in any other (potentially lethal) disease. The clinician can only establish this diagnosis if he/she has knowledge of the signs and symptoms of AHT, risk factors, the differential diagnosis and which additional investigations to perform, the more so since parents seldom will describe the true state of affairs spontaneously

    Management of Interests & External Interactions: A SPECTRUM Policy Document

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    The SPECTRUM Management of Interests and External Interactions document aims to make clear the official position of the Consortium with respect to engagement with external partners particularly where they may constitute, or give rise to, a conflict of interest or present a reputational or other risk to the Consortium. Additionally, it: - clarifies what interests and interactions are covered by the policy, - explains what is meant by conflict of interest, - provides guidance to members on the processes for proactively identifying risks and conflicts in order to prevent them, and how to mitigate and manage them if and when they do arise

    The SPECTRUM Consortium : A new UK Prevention Research Partnership consortium focussed on the commercial determinants of health, the prevention of non-communicable diseases, and the reduction of health inequalities

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    The main causes of non-communicable diseases (NCDs), health inequalities and health inequity include consumption of unhealthy commodities such as tobacco, alcohol and/or foods high in fat, salt and/or sugar. These exposures are preventable, but the commodities involved are highly profitable. The economic interests of 'Unhealthy Commodity Producers' (UCPs) often conflict with health goals but their role in determining health has received insufficient attention. In order to address this gap, a new research consortium has been established. This open letter introduces the SPECTRUM ( S haping Public h Ealth poli Cies To Reduce ineq Ualities and har M) Consortium: a multi-disciplinary group comprising researchers from 10 United Kingdom (UK) universities and overseas, and partner organisations including three national public health agencies in Great Britain (GB), five multi-agency alliances and two companies providing data and analytic support. Through eight integrated work packages, the Consortium seeks to provide an understanding of the nature of the complex systems underlying the consumption of unhealthy commodities, the role of UCPs in shaping these systems and influencing health and policy, the role of systems-level interventions, and the effectiveness of existing and emerging policies. Co-production is central to the Consortium's approach to advance research and achieve meaningful impact and we will involve the public in the design and delivery of our research. We will also establish and sustain mutually beneficial relationships with policy makers, alongside our partners, to increase the visibility, credibility and impact of our evidence. The Consortium's ultimate aim is to achieve meaningful health benefits for the UK population by reducing harm and inequalities from the consumption of unhealthy commodities over the next five years and beyond
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