129 research outputs found

    Lithium diffusion in congruent LiNbO3 single crystals at low temperatures probed by neutron reflectometry

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    The self-diffusion of lithium in congruent LiNbO3 single crystals was investigated at low temperatures between 379 and 523 K by neutron reflectometry. From measurements on 6LiNbO3 (amorphous film)/natLiNbO3 (single crystal) samples, Li self-diffusivities were determined in single crystals down to extremely low values of 1 × 10−25 m2 s−1 on small length scales of 1–10 nm. The measured diffusivities are in excellent agreement with (extrapolated) literature data obtained by experiments based on Secondary Ion Mass Spectrometry and Impedance Spectroscopy. The tracer diffusivities can be described by a single Arrhenius line over ten orders of magnitude with an activation enthalpy of 1.33 eV, which corresponds to the migration energy of a single Li vacancy. A deviation from the Arrhenius behaviour at low temperatures, e.g., due to defect cluster formation is not observed.EC/FP7/226507DFG/Schm 1569/18DFG/He 1574/13CP-CSA_INFRA-2008-1.1.1 Number 226507-NMI

    Alternative splicing substantially diversifies the transcriptome during early photomorphogenesis and correlates with the energy availability in arabidopsis

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    Plants use light as source of energy and information to detect diurnal rhythms and seasonal changes. Sensing changing light conditions is critical to adjust plant metabolism and to initiate developmental transitions. Here we analyzed transcriptome-wide alterations in gene expression and alternative splicing (AS) of etiolated seedlings undergoing photomorphogenesis upon exposure to blue, red, or white light. Our analysis revealed massive transcriptome reprograming as reflected by differential expression of ~20% of all genes and changes in several hundred AS events. For more than 60% of all regulated AS events, light promoted the production of a presumably protein-coding variant at the expense of an mRNA with nonsense-mediated decay-triggering features. Accordingly, AS of the putative splicing factor REDUCED RED-LIGHT RESPONSES IN CRY1CRY2 BACKGROUND 1 (RRC1), previously identified as a red light signaling component, was shifted to the functional variant under light. Downstream analyses of candidate AS events pointed at a role of photoreceptor signaling only in monochromatic but not in white light. Furthermore, we demonstrated similar AS changes upon light exposure and exogenous sugar supply, with a critical involvement of kinase signaling. We propose that AS is an integration point of signaling pathways that sense and transmit information regarding the energy availability in plants

    Informing investment to reduce inequalities: a modelling approach

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    Background: Reducing health inequalities is an important policy objective but there is limited quantitative information about the impact of specific interventions. Objectives: To provide estimates of the impact of a range of interventions on health and health inequalities. Materials and methods: Literature reviews were conducted to identify the best evidence linking interventions to mortality and hospital admissions. We examined interventions across the determinants of health: a ‘living wage’; changes to benefits, taxation and employment; active travel; tobacco taxation; smoking cessation, alcohol brief interventions, and weight management services. A model was developed to estimate mortality and years of life lost (YLL) in intervention and comparison populations over a 20-year time period following interventions delivered only in the first year. We estimated changes in inequalities using the relative index of inequality (RII). Results: Introduction of a ‘living wage’ generated the largest beneficial health impact, with modest reductions in health inequalities. Benefits increases had modest positive impacts on health and health inequalities. Income tax increases had negative impacts on population health but reduced inequalities, while council tax increases worsened both health and health inequalities. Active travel increases had minimally positive effects on population health but widened health inequalities. Increases in employment reduced inequalities only when targeted to the most deprived groups. Tobacco taxation had modestly positive impacts on health but little impact on health inequalities. Alcohol brief interventions had modestly positive impacts on health and health inequalities only when strongly socially targeted, while smoking cessation and weight-reduction programmes had minimal impacts on health and health inequalities even when socially targeted. Conclusions: Interventions have markedly different effects on mortality, hospitalisations and inequalities. The most effective (and likely cost-effective) interventions for reducing inequalities were regulatory and tax options. Interventions focused on individual agency were much less likely to impact on inequalities, even when targeted at the most deprived communities

    Cost-effectiveness of HBV and HCV screening strategies:a systematic review of existing modelling techniques

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    Introduction: Studies evaluating the cost-effectiveness of screening for Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) are generally heterogeneous in terms of risk groups, settings, screening intervention, outcomes and the economic modelling framework. It is therefore difficult to compare cost-effectiveness results between studies. This systematic review aims to summarise and critically assess existing economic models for HBV and HCV in order to identify the main methodological differences in modelling approaches. Methods: A structured search strategy was developed and a systematic review carried out. A critical assessment of the decision-analytic models was carried out according to the guidelines and framework developed for assessment of decision-analytic models in Health Technology Assessment of health care interventions. Results: The overall approach to analysing the cost-effectiveness of screening strategies was found to be broadly consistent for HBV and HCV. However, modelling parameters and related structure differed between models, producing different results. More recent publications performed better against a performance matrix, evaluating model components and methodology. Conclusion: When assessing screening strategies for HBV and HCV infection, the focus should be on more recent studies, which applied the latest treatment regimes, test methods and had better and more complete data on which to base their models. In addition to parameter selection and associated assumptions, careful consideration of dynamic versus static modelling is recommended. Future research may want to focus on these methodological issues. In addition, the ability to evaluate screening strategies for multiple infectious diseases, (HCV and HIV at the same time) might prove important for decision makers

    Cost-effectiveness of oral versus intravenous antibiotics (OVIVA) in patients with bone and joint infection : evidence from a non-inferiority trial

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    Background: Bone and joint infections are becoming increasingly common and are usually treated with surgery and a course of intravenous antibiotics. However, there is no evidence to support the superiority of intravenous therapy and there is a growing body of literature showing that oral therapy is effective in treating these infections. Given this lack of evidence the clinical trial ‘Oral Versus Intravenous Antibiotics’ (OVIVA) was designed to assess the clinical and cost-effectiveness of intravenous versus oral antibiotics for the treatment of bone and joint infections, using a non-inferiority design. Clinical results from the trial indicate that oral antibiotics are non-inferior to intravenous antibiotics. The aim of this paper is to evaluate the cost-effectiveness of intravenous compared to oral antibiotics for treating bone and joint infections, using data from OVIVA. Methods: A cost-utility analysis was carried out, the main economic outcome measure was the quality adjusted life-year, measured using the EQ-5D-3L questionnaire, combined with costs to estimate cost-effectiveness over 12-months follow-up. Results: Results show that costs were significantly lower in the oral arm compared to the intravenous arm, a difference of £2,740 (95% confidence interval £1,488 to £3,992). Results of four sensitivity analyses were consistent with the base-case results. QALYs were marginally higher in the oral arm, however this difference was not statistically significant; -0.007 (95% confidence interval -0.045 to 0.031). Conclusions: Treating patients with bone and joint infections for the first six weeks of therapy with oral antibiotics is both less costly and does not result in detectable differences in quality of life compared to treatment with intravenous antibiotics. Adopting a practice of treating bone and joint infections with oral antibiotics early in the course of therapy could potentially save the UK National Health Service over £17 million annually

    Dependency of magnetocardiographically determined fetal cardiac time intervals on gestational age, gender and postnatal biometrics in healthy pregnancies

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    BACKGROUND: Magnetocardiography enables the precise determination of fetal cardiac time intervals (CTI) as early as the second trimester of pregnancy. It has been shown that fetal CTI change in course of gestation. The aim of this work was to investigate the dependency of fetal CTI on gestational age, gender and postnatal biometric data in a substantial sample of subjects during normal pregnancy. METHODS: A total of 230 fetal magnetocardiograms were obtained in 47 healthy fetuses between the 15(th )and 42(nd )week of gestation. In each recording, after subtraction of the maternal cardiac artifact and the identification of fetal beats, fetal PQRST courses were signal averaged. On the basis of therein detected wave onsets and ends, the following CTI were determined: P wave, PR interval, PQ interval, QRS complex, ST segment, T wave, QT and QTc interval. Using regression analysis, the dependency of the CTI were examined with respect to gestational age, gender and postnatal biometric data. RESULTS: Atrioventricular conduction and ventricular depolarization times could be determined dependably whereas the T wave was often difficult to detect. Linear and nonlinear regression analysis established strong dependency on age for the P wave and QRS complex (r(2 )= 0.67, p < 0.001 and r(2 )= 0.66, p < 0.001) as well as an identifiable trend for the PR and PQ intervals (r(2 )= 0.21, p < 0.001 and r(2 )= 0.13, p < 0.001). Gender differences were found only for the QRS complex from the 31(st )week onward (p < 0.05). The influence on the P wave or QRS complex of biometric data, collected in a subgroup in whom recordings were available within 1 week of birth, did not display statistical significance. CONCLUSION: We conclude that 1) from approximately the 18(th )week to term, fetal CTI which quantify depolarization times can be reliably determined using magnetocardiography, 2) the P wave and QRS complex duration show a high dependency on age which to a large part reflects fetal growth and 3) fetal gender plays a role in QRS complex duration in the third trimester. Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation

    Carbon nanoparticles in lateral flow methods to detect genes encoding virulence factors of Shiga toxin-producing Escherichia coli

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    The use of carbon nanoparticles is shown for the detection and identification of different Shiga toxin-producing Escherichia coli virulence factors (vt1, vt2, eae and ehxA) and a 16S control (specific for E. coli) based on the use of lateral flow strips (nucleic acid lateral flow immunoassay, NALFIA). Prior to the detection with NALFIA, a rapid amplification method with tagged primers was applied. In the evaluation of the optimised NALFIA strips, no cross-reactivity was found for any of the antibodies used. The limit of detection was higher than for quantitative PCR (q-PCR), in most cases between 104 and 105 colony forming units/mL or 0.1–0.9 ng/μL DNA. NALFIA strips were applied to 48 isolates from cattle faeces, and results were compared to those achieved by q-PCR. E. coli virulence factors identified by NALFIA were in very good agreement with those observed in q-PCR, showing in most cases sensitivity and specificity values of 1.0 and an almost perfect agreement between both methods (kappa coefficient larger than 0.9). The results demonstrate that the screening method developed is reliable, cost-effective and user-friendly, and that the procedure is fast as the total time required is <1 h, which includes amplification

    The feasibility of a randomised controlled trial to compare the cost-effectiveness of palliative cardiology or usual care in people with advanced heart failure: Two exploratory prospective cohorts

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    © 2018, © The Author(s) 2018. Background: The effectiveness of cardiology-led palliative care is unknown; we have insufficient information to conduct a full trial. Aim: To assess the feasibility (recruitment/retention, data quality, variability/sample size estimation, safety) of a clinical trial of palliative cardiology effectiveness. Design: Non-randomised feasibility. Setting/participants: Unmatched symptomatic heart failure patients on optimal cardiac treatment from (1) cardiology-led palliative service (caring together group) and (2) heart failure liaison service (usual care group). Outcomes/safety: Symptoms (Edmonton Symptom Assessment Scale), Kansas City Cardiomyopathy Questionnaire, performance, understanding of disease, anticipatory care planning, cost-effectiveness, survival and carer burden. Results: A total of 77 participants (caring together group = 43; usual care group = 34) were enrolled (53% men; mean age 77 years (33–100)). The caring together group scored worse in Edmonton Symptom Assessment Scale (43.5 vs 35.2) and Kansas City Cardiomyopathy Questionnaire (35.4 vs 39.9). The caring together group had a lower consent/screen ratio (1:1.7 vs 1: 2.8) and few died before approach (0.08% vs 16%) or declined invitation (17% vs 37%). Data quality: At 4 months, 74% in the caring together group and 71% in the usual care group provided data. Most attrition was due to death or deterioration. Data quality in self-report measures was otherwise good. Safety: There was no difference in survival. Symptoms and quality of life improved in both groups. A future trial requires 141 (202 allowing 30% attrition) to detect a minimal clinical difference (1 point) in Edmonton Symptom Assessment Scale score for breathlessness (80% power). More participants (176; 252 allowing 30% attrition) are needed to detect a 10.5 change in Kansas City Cardiomyopathy Questionnaire score (80% power; minimum clinical difference = 5). Conclusion: A trial to test the clinical effectiveness (improvement in breathlessness) of cardiology-led palliative care is feasible
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