114 research outputs found
Influence of compositionally induced defects on the vibrational properties of device grade Cu2ZnSnSe4 absorbers for kesterite based solar cells
This work presents a detailed analysis of the impact of compositionally induced defects on the vibrational properties of Cu2ZnSnSe4 absorbers for kesterite based solar cells. Systematic changes in the intensity of the E and B modes located around the 170, 220, and 250 cm-1 frequency regions, which involve mostly cation vibrations, were observed and analyzed in relation to the occurrence of different kinds of defect clusters involving VCu, ZnCu, ZnSn, CuZn, and SnZn point defects. Additional changes are also interpreted in terms of the appearance of SnSe, ZnSe, and CuSe-like contributions at the 185 and 250 cm-1 spectral regions, respectively. The sensitivity of the Raman measurements to the presence of these kinds of defects corroborates the potential of Raman scattering for point defect assessment in these systems. © 2015 AIP Publishing LLCPeer ReviewedPostprint (published version
Influence of compositionally induced defects on the vibrational properties of device grade Cu2ZnSnSe4 absorbers for kesterite based solar cells
This work presents a detailed analysis of the impact of compositionally induced defects on the vibrational properties of Cu2ZnSnSe4 absorbers for kesterite based solar cells. Systematic changes in the intensity of the E and B modes located around the 170, 220, and 250 cm 1 frequency regions, which involve mostly cation vibrations, were observed and analyzed in relation to the occurrence of different kinds of defect clusters involving VCu, ZnCu, ZnSn, CuZn, and SnZn point defects. Additional changes are also interpreted in terms of the appearance of SnSe, ZnSe, and CuSe-like contributions at the 185 and 250 cm 1 spectral regions, respectively. The sensitivity of the Raman measurements to the presence of these kinds of defects corroborates the potential of Raman scattering for point defect assessment in these systems
The burden of chronic obstructive pulmonary disease associated with maintenance monotherapy in the UK
Susan C Edwards,1 Sian E Fairbrother,2 Anna Scowcroft,3 Gavin Chiu,4 Andrew Ternouth,3 Brian J Lipworth5 1Department of Market Access Pricing & Outcomes Research, 2Department of Medical Affairs - Respiratory, 3Department of Market Access, 4Department of Prescription Medicine - Respiratory, Boehringer Ingelheim, Bracknell, UK; 5Asthma and Allergy Research Group, Division of Cardiovascular and Diabetes Medicine, Scottish Centre for Respiratory Research, University of Dundee, Ninewells Hospital and Medical School, Dundee, UK Background: This study characterized a cohort of chronic obstructive pulmonary disease (COPD) patients on maintenance bronchodilator monotherapy for ≥6 months to establish their disease burden, measured by health care utilization.Methods: Data were extracted from the UK Clinical Practice Research Datalink and linked to Hospital Episode Statistics. The monotherapy period spanned the first prescription of a long-acting β2-adrenergic agonist or a long-acting muscarinic antagonist until the end of the study (December 31, 2013) or until step up to dual/triple therapy, for example, addition of another long-acting bronchodilator, an inhaled corticosteroid, or both. A minimum of four consecutive prescriptions and 6 months on continuous monotherapy were required. Patients <50 years old at first COPD diagnosis or with another significant respiratory disease before starting monotherapy were excluded. Disease burden was evaluated by measuring patients’ rate of face-to-face interactions with a health care professional (HCP), COPD-related exacerbations, hospitalizations, and referrals.Results: A cohort of 8,811 COPD patients (95% Global initiative for chronic Obstructive Lung Disease stage A/B) on maintenance monotherapy was identified between 2002 and 2013; 45% of these patients were still on monotherapy by the end of the study. Median time from first COPD diagnosis to first monotherapy prescription was 56 days, while the median time on maintenance bronchodilator monotherapy was 2 years. The median number of prescriptions was 14. On average, patients had 15 HCP interactions per year, and one in ten patients experienced a COPD exacerbation (N=8,811). One in 50 patients were hospitalized for COPD per year (n=4,848).Conclusion: The average monotherapy-treated patient had a higher than average HCP interaction rate. We also identified a large cohort of patients who were stepped up to triple therapy despite a low rate of exacerbations. The use of the new class of long-acting muscarinic antagonist/long-acting β2-adrenergic agonist fixed-dose combinations may provide a useful step-up treatment option in such monotherapy patients, before the use of inhaled corticosteroids. Keywords: COPD, UK primary care setting, bronchodilators, prescribing patterns, monotherap
Adapted qPCR methodology to detect telomere oxidative damage (TOD) associated with telomere attrition (TA) in murine tissue
Numerous Studies suggest that oxidative stress (OS) is associated with telomere attrition (TA) but they rarely directly assay telomeric oxidative damage (TOD). TOD can alter shelterin binding, induce replication fork stalling and inhibit telomerase activity. We used a previously published method 1 to measure TOD and adapted it for use in murine tissue. Our model is a C57BL/6J mouse strain and we used qPCR and a formamidopyrimidine DNA glycosylase (FPG) enzyme-based qPCR method to directly determine TOD. FPG analysis compares reaction efficiencies before and after treatment. FPG is normally involved in base excision repairs pathways, removing oxidized Purines (notably 8-Oxo Guanine). A reduction in the efficiency of the qPCR indicates the presence of 8-oxo guanine in the telomeric tract ie TOD
Vibrational properties of sulfoselenide solid solutions
In this work, Raman spectroscopy and X-ray diffraction were applied together
to evaluate the crystal structure and the phonon modes of photovoltaic grade
Cu 2ZnSn(SxSe1âx)4 thin films, leading to a complete characterization of their
structural and vibrational properties. Vibrational characterization has been
based on Raman scattering measurements performed with different excitation
wavelengths and polarization configurations. Analysis of the experimental
spectra has permitted identification of 19 peaks, which positions are in good
accord with theoretical predictions. Besides, the observation of Cu
2ZnSnS4-like A symmetry peaks related to S vibrations and Cu 2ZnSnSe4-like A
symmetry peaks related to Se vibrations, additional Raman peaks,
characteristic of the solid solution and previously not reported, are
observed, and are attributed to vibrations involving both S and Se anions
Childrenâs learning from a Smokefree sports programme: implications for health education
Objective:
This article reports on a qualitative evaluation of the Love Life, Smokefree Sports primary school pilot intervention. This 8-week programme used sports and physical activity sessions to convey Smokefree messages to 120 children aged 10 and 11 in two primary schools in Sheffield in 2018. The study aimed to understand childrenâs experiences of participating in the programme. Its objectives were to explore childrenâs recall of the health promotion messages associated with each of the learning sessions; explore childrenâs perceptions of the meaningfulness of those messages in the context of their everyday lives; and identify and understand any contextual factors that might impact upon childrenâs recall and/or the meaningfulness of the Smokefree messages.
Method:
Qualitative data were generated with 25 children through focus groups after the programme concluded. Data were analysed thematically using cross-sectional, categorical indexing.
Results:
Learning from the programme was particularly likely to be described as meaningful by children when they could interact with material and visual representations of complex ideas and when sessions involved strongly embodied experiences. However, children did not always find it easy to relate learning to their everyday lives and sometimes struggled to reconcile pre-existing, contextualised understandings with intervention messages. We mobilise the concept of critical health literacy as a theoretical lens through which to interpret these findings.
Conclusion:
Health education should be meaningful in the context of childrenâs everyday lives. Starting from the premise that children are active critical health literacy practitioners and working with them to design and evaluate health education initiatives can promote this
Randomized trial of complete versus lesion-only revascularization in patients undergoing primary percutaneous coronary intervention for STEMI and Multivessel Disease
BACKGROUND: The optimal management of patients found to have multivessel disease while undergoing primary percutaneous coronary intervention (P-PCI) for ST-segment elevation myocardial infarction is uncertain.  OBJECTIVES: CvLPRIT (Complete versus Lesion-only Primary PCI trial) is a U.K. open-label randomized study comparing complete revascularization at index admission with treatment of the infarct-related artery (IRA) only.  METHODS: After they provided verbal assent and underwent coronary angiography, 296 patients in 7 U.K. centers were randomized through an interactive voice-response program to either in-hospital complete revascularization (n = 150) or IRA-only revascularization (n = 146). Complete revascularization was performed either at the time of P-PCI or before hospital discharge. Randomization was stratified by infarct location (anterior/nonanterior) and symptom onset (â€3 h or >3 h). The primary endpoint was a composite of all-cause death, recurrent myocardial infarction (MI), heart failure, and ischemia-driven revascularization within 12 months.  RESULTS: Patient groups were well matched for baseline clinical characteristics. The primary endpoint occurred in 10.0% of the complete revascularization group versus 21.2% in the IRA-only revascularization group (hazard ratio: 0.45; 95% confidence interval: 0.24 to 0.84; p = 0.009). A trend toward benefit was seen early after complete revascularization (p = 0.055 at 30 days). Although there was no significant reduction in death or MI, a nonsignificant reduction in all primary endpoint components was seen. There was no reduction in ischemic burden on myocardial perfusion scintigraphy or in the safety endpoints of major bleeding, contrast-induced nephropathy, or stroke between the groups.  CONCLUSIONS: In patients presenting for P-PCI with multivessel disease, index admission complete revascularization significantly lowered the rate of the composite primary endpoint at 12 months compared with treating only the IRA. In such patients, inpatient total revascularization may be considered, but larger clinical trials are required to confirm this result and specifically address whether this strategy is associated with improved survival. (Complete Versus Lesion-only Primary PCI Pilot Study [CvLPRIT]; ISRCTN70913605)
Third-generation professional doctorates in nursing: the move to clarity in learning product differentiation
Context: Professional doctorates have been a part of the academic landscape for many years. Over this time, their focus, structure and mode of delivery have changed significantly as the terrain of professional practice has developed. In this paper we articulate this development over time through discussion of the evolution of first- and second-generation professional doctorates, and argue that there is a need for a third-generation doctorate with greater clarity regarding focus, structure and mode of delivery, in the context of advanced professional practice.
Aims: A scoping review was undertaken of the development of professional doctorates in the discipline of nursing to inform thinking with regard to future design work for a post-masters (nurse practitioner endorsement) professional doctorate.
Conclusion: In the context of the absence of any identified published outcome-based evidence of the value of first- or second-generation professional doctorates in general, and specifically in nursing, a third-generation evolution is proposed. This is based on the conclusion that the lack of identified outcomes is based not only on the axiomatic absence of research, but also that this may be symptomatic of a prevailing lack of clarity in programme design. A third-generation professional doctorate for nursing offers an opportunity to focus on congruence and internal consistency between the aims of the programme, learning outcomes, learning content and design, and the assessment.
Implications for practice development:
- The third-generation professional doctorate would no longer need to be distinguished from other degrees via an expression of what it is not, but rather would set out what it is
- The educational product, with clear processes and content that are congruent with the course aims, could be clearly described as a self-contained entity more capable of producing measurable outcomes
- Practice development is an integral part of the learning product through being a prescribed method in the research component of the coursesch_nur7pub5315pub2 [4
Choice of gDNA isolation method has a significant impact on average murine Telomere Length estimates
Telomere Length (TL) and integrity is significantly associated with age-related disease, multiple genetic and environmental factors. We observe mouse genomic DNA (gDNA) isolation methods to have a significant impact on average TL estimates. The canonical qPCR method does not measure TL directly but via the ratio of telomere repeats to a single copy gene (SCG) generating a T/S ratio. We use a monochromatic-multiplex-qPCR (mmqPCR) method which multiplexes the PCR and enables quantification of the target and the single copy gene within the same qPCR reaction. We demonstrate that TL measurements, from murine gDNA, isolated via Spin Columns (SC) and Magnetic Beads (MB), generate significantly smaller T/S ratios compared to gDNA isolated via traditional phenol/chloroform methods. The former methods may impede correct TL estimation by producing non representative fragment sets and reducing qPCR efficacy. This work highlights discrepancies in TL measurements due to different extraction techniques. We recommend the use of gDNA isolation methods that are shown to preserve DNA length and integrity, such as phenol/chloroform isolation. We propose that widely used high throughput DNA isolation methodologies can create spurious associations within a sample set, thus creating misleading data. We suggest that published TL associations should be revisited in the light of these dat
- âŠ