613 research outputs found

    Combinatorial synthesis and screening of chalcogenide materials for data storage

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    For more than 15 years researchers at the Optoelectronics Research Centre at the University of Southampton have been developing novel compositions of chalcogenide glasses for a wide range of optical applications. Recently this expertise has been combined with those of Ilika Technologies Ltd and the School of Chemistry to focus on the development of enhanced chalcogenide materials for OUM and optical data storage applications. In our talk, we report on our high throughput methodology which allows rapid, reproducible and comprehensive mapping of phase diagrams and screening of optical, thermal and electrical properties. These procedures were initially applied to Ge:Sb:Te compositions where we were able to synthesis and analyse over 4000 sample points spanning the entire ternary system. In order to process such large volumes of compositions, novel screening techniques and strategies have been employed. We are applying this methodology to other novel compositions and our findings are reported

    Chalcogenides applied to microring switching

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    We show that switching a phase-change material between its two bonding states can be used to shift the resonant wavelength of a ring resonator and change its Q-factor and extinction ratio, in a reversible and non-volatile way

    Chalcogenide glasses for photonics device applications

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    Chalcogenides are compounds formed predominately from one or more of the chalcogen elements; sulphur, selenium and tellurium. Although first studied over fifty years ago, interest in chalcogenide glasses has, over the past few years, increased significantly as glasses, crystals and alloys find new life in a wide range of photonic devices. This chapter begins with an overview of chalcogenide glass compositions, their purification, synthesis and fabrication. Focussing on more novel gallium lanthanum sulphide based chalcogenides, as well as reviewing more established materials such as arsenic trisulphide based glasses we then explore the purification and synthesis of these materials, along with their basic optical and thermal properties. Next the fabrication of these versatile glasses into a variety of forms; including thin films, microspheres and optical fibers is explained. This chapter ends with an overview of representative applications of these exciting optoelectronic materials

    BOXCAR user and programmer manual, version 1.0

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    DTFH61-87-C-00032This Manual presents an overview, user instructions and technical backup for the computer program BOXCAR. BOXCAR is a program for the structural analysis and design of reinforced concrete box sections. It has been written to run on IBM or IBM compatible microcomputers. The input routines are user friendly; only minimal experience with computers is required prior to use. Most parameters can be controlled by the user. Knowledge of structural design codes for culverts is required. BOXCAR completes structural analysis for loads due to box weight, soil weight, internal gravity fluid weight, live loads and user specified surcharge loads. Forces resulting from each load condition may be printed out separately. Structural design is in accordance with AASHTO. Design criteria include ultimate flexure, diagonal tension, service load crack control, and service load fatigue. The quantity of output is controlled by the user. All output is formatted for 8.5 by 11 inch paper. User instructions include descriptions of all input variables and design examples. The programmer manual includes listings of all technical subroutines

    The impact of liraglutide on diabetes-related foot ulceration and associated complications in patients with type 2 diabetes at high risk for cardiovascular events: Results from the LEADER trial

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    OBJECTIVE: Diabetes-related foot ulcers (DFUs) and their sequelae result in large patient and societal burdens. Long-term data determining the efficacy of individual glucose-lowering agents on DFUs are lacking. Using existing data from the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial, we conducted post hoc analyses assessing the impact of liraglutide versus placebo in people with type 2 diabetes and at high risk of cardiovascular (CV) events on the incidence of DFUs and their sequelae. RESEARCH DESIGN AND METHODS: The LEADER trial (NCT01179048) was a randomized, double-blind, multicenter, CV outcomes trial assessing liraglutide (1.8 mg/day) versus placebo, in addition to standard of care, for up to 5 years. Information on DFUs was collected systematically during the trial, and DFU complications were assessed post hoc through reviewing case narratives. RESULTS: During a median of 3.8 years' follow-up, similar proportions of patients reported at least one episode of DFU in the liraglutide and placebo groups (3.8% [176/4,668] versus 4.1% [191/4,672], respectively; hazard ratio [HR] 0.92 [95% CI 0.75, 1.13; P = 0.41]). Analysis of DFU-related complications demonstrated a significant reduction in amputations with liraglutide versus placebo (HR 0.65 [95% CI 0.45, 0.95; P = 0.03]). However, no differences were found for foot infections, involvement of underlying structures, or peripheral revascularization in the main analysis. CONCLUSIONS: Treatment with liraglutide in patients with type 2 diabetes and at high risk of CV events in the LEADER trial did not increase the risk of DFU events and was associated with a significantly lower risk of DFU-related amputations compared with placebo. This association, possibly due to chance, needs further investigation

    Volatile and glycosidically bound composition of Loureiro and Alvarinho wines

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    Composition of Loureiro and Alvarinho wines from the Vinhos Verdes region, respecting free volatile compounds as well as glycosidically bound aroma precursors, was exhaustively determined by GC-MS after adsorption on XAD-2 resin. On the whole, were identified and quantified 120 volatile compounds in the free fraction and 77 glycosidically bound compounds, belonging to C6-compounds, alcohols, fatty acids ethyl esters, esters of organic acids, acetates, monoterpenic alcohols, monoterpenic oxides and diols, C13-norisoprenoids, volatile phenols, volatile fatty acids and carbonyl compounds. Globally, the wines of the two cultivars present similar composition on volatiles. However, respecting varietal compounds, Loureiro wines are richer than Alvarinho ones with regard to C6-compounds and monoterpenic compounds, occurring the opposite for volatile phenols. It was also demonstrate that wines of both varieties may benefit the aroma reserve, present as glycoconjugates, as it is susceptible of being technologically explored. Linalool, Ho-trienol, α-terpineol, contributing with fruity and floral notes, and β-damascenone mostly for Alvarinho, confering tropical fruit notes, are the varietal compounds which may particularly influence the aroma of these wines. Respecting fermentative compounds, Alvarinho is also particularly rich in fatty acids ethyl esters related to lipid metabolism and acetates of fusel alcohols, which can provide it a fruity character; Loureiro contains higher levels of esters of organic acids and 2-phenylethanol, conferring fruity and floral notes. Sensory analysis agree with chemical analyses showing a pronounced tree and tropical fruit character for Alvarinho wines while Loureiro wines present more intense citrus fruit notes.Centre of Biological Engineering of Universidade do Minho; Estação Vitivinícola Amândio Galhano (EVAG); Solar de Serrade; EVAG; Comissão de Viticultura da Região dos Vinhos Verdes

    Multi-channel R-matrix analysis of CNO cycle reactions

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    The CNO cycle is the main process for hydrogen burning in stars somewhat more massive than the Sun. The reaction cross sections at Gamow energies are typically in the femto to pico-barn range and are consequently very difficult to measure experimentally. The CNO reaction rates are based on extrapolations of experimental data from higher energies. We are developing a multi-channel R-matrix code (AZURE) to provide a new and more comprehensive tool for fitting experimental data and making extrapolations to lower energies in all reaction and scattering channels. The 14N(p,γ )15O reaction is the slowest reaction of the CNO cycle and thus it determines the energy production rate of CNO burning. Furthermore, this reaction plays an important role in the determination of Globular Cluster age, since the position of the turnoff point, at which the GC stars escape from the Main Sequence, is powered by the onset of the CNO burning, whose bottleneck is the 14N(p, γ )15O. We have made a reanalysis of the most recent experimental data on the ground state and the 6.18 MeV transitions. The ratio of the cross sections of the 15N(p, γ )16O and 15N(p,α)12C reactions determines how much catalytic material passes to higher CNO cycles and has an effect on the production of heavier elements, particularly 16O and 17O. Simultaneous analysis of both reactions for all channels suggests that the ratio σγ/σα is smaller than previously reported

    Interpersonal effects of parents and adolescents on each other’s health behaviours: a dyadic extension of the theory of planned behaviour

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    Objective: Interpersonal relationships are important predictors of health outcomes and interpersonal influences on behaviours may be key mechanisms underlying such effects. Most health behaviour theories focus on intrapersonal factors and may not adequately account for interpersonal influences. We evaluate a dyadic extension of the Theory of Planned Behaviour by examining whether parent and adolescent characteristics (attitudes, subjective norms, perceived behavioural control and intentions) are associated with not only their own but also each other’s intentions/behaviours. Design: Using the Actor-Partner Interdependence Model, we analyse responses from 1717 parent-adolescent dyads from the Family Life, Activity, Sun, Health, and Eating study. Main Outcome Measures: Adolescents/parents completed self-reports of their fruit and vegetable consumption, junk food and sugary drinks consumption, engagement in physical activity, and engagement in screen time sedentary behaviours. Results: Parent/adolescent characteristics are associated with each other’s health-relevant intentions/behaviours above the effects of individuals’ own characteristics on their own behaviours. Parent/adolescent characteristics covary with each other’s outcomes with similar strength, but parent characteristics more strongly relate to adolescent intentions, whereas adolescent characteristics more strongly relate to parent behaviours. Conclusions: Parents and adolescents may bidirectionally influence each other’s health intentions/behaviours. This highlights the importance of dyadic models of health behaviour and suggests intervention targets

    Telomere fusion threshold identifies a poor prognostic subset of breast cancer patients

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    Telomere dysfunction and fusion can drive genomic instability and clonal evolution in human tumours, including breast cancer. Telomere length is a critical determinant of telomere function and has been evaluated as a prognostic marker in several tumour types, but it has yet to be used in the clinical setting. Here we show that high-resolution telomere length analysis, together with a specific telomere fusion threshold, is highly prognostic for overall survival in a cohort of patients diagnosed with invasive ductal carcinoma of the breast (n = 120). The telomere fusion threshold defined a small subset of patients with an extremely poor clinical outcome, with a median survival of less than 12 months (HR = 21.4 (7.9-57.6), P < 0.0001). Furthermore, this telomere length threshold was independent of ER, PGR, HER2 status, NPI, or grade and was the dominant variable in multivariate analysis. We conclude that the fusogenic telomere length threshold provides a powerful, independent prognostic marker with clinical utility in breast cancer. Larger prospective studies are now required to determine the optimal way to incorporate high-resolution telomere length analysis into multivariate prognostic algorithms for patients diagnosed with breast cancer
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