Effect of trivalent dopants on local coordination and electronic structure in crystalline and amorphous ZnO

Density functional theory calculations are used to investigate the structure and binding energies of clusters formed between oxygen vacancies and trivalent dopant atoms (indium, gallium and aluminium) substituted into zinc oxide. Our results show that indium atoms form stable nearest neighbour pairs with oxygen vacancies, while gallium and aluminium atoms associate with them at next nearest neighbour sites. Using a combination of classical molecular dynamics and Reverse Monte Carlo methods, models of amorphous indium zinc oxide at different compositions up to 25 at.% indium are created. Analysis of these models indicates that, in contrast with the trend observed in the crystal phase, indium does not tend to be undercoordinated in the amorphous phase. The value of the band gap obtained for the amorphous compositions is smaller than that of crystalline undoped ZnO by about 0.8 eV and is largely independent of the indium concentration. Electron effective masses calculated in all the amorphous models decrease with increasing amount of indium due to the larger dispersion of the In-dominated conduction bands. This trend is compared to resistivity measurements on amorphous indium zinc oxide which also decrease with increasing indium concentration.Financial support for this work is provided by the European Commission through contract No. NMP3-LA-2010-246334 (ORAMA).This is the original submitted version of the article. It does not incorporate changes arising from peer-review. The final peer-reviewed version of the article has been published in Thin Solid Films as 'Effect of trivalent dopants on local coordination and electronic structure in crystalline and amorphous ZnO' and is available at http://www.sciencedirect.com/science/article/pii/S004060901301002X

"I have failed to separate my HIV from this pain": the challenge of managing chronic pain among people with HIV

Pain is a highly prevalent and burdensome symptom among people with HIV (PWH). This study aims to identify how the experience of living with HIV and chronic pain influences pain beliefs, health-seeking and pain management. Thirty-nine purposively sampled PWH with chronic pain (sample characteristics = 61% women, 79% Black, Asian and minority ethnic groups, 18% men who have sex with men, 45-54 median age category) participated in focus groups in London. Focus groups were co-facilitated with community members. Transcripts wereanalysed using a thematic approach. Findings revealed that HIV stigma, fractured care pathways, and general practitioners' lack of HIV training are barriers to supported pain management. Unaddressed pain results in poorer mental health and reduced quality of life, which has important clinical implications for HIV treatment adherence. Creating HIV-specific pain resources, activating social networks, and pain self-management techniques are potential solutions. Person-centred assessment and HIV training is needed to help clinicians identify PWH with chronic pain. Clear guidelines need to be developed to identify which health service providers are responsible for chronic pain management in PWH. This study generated a refined version of the Fear Avoidance Model that introduces a dimension of HIV-specific behaviours that impact PWHs seeking chronic pain management

X-ray diffraction and computer simulation studies on the structure of homophase and heterophase interfaces in metals

We use the Thin Film X-ray Diffraction (TFXD) technique in conjunction with computer simulation methods to obtain detailed information on the structure of complex interfacial systems in metals. Results for three types of interfaces are presented. These are, a [Sigma] 13 [001] twist homophase boundary in a Au-Cu 10 at. % alloy, a [Sigma] 26/29 [001] twist Au-Pd heterophase boundary and finally the [Sigma] 4/5 [001] twist Ag-Cu heterophase boundary. For the homophase boundary in Au-Cu we demonstrate the utility of the X-ray technique in studying the effects of solute segregation on boundary structure. Calculations predict trends which are in agreement with the experimental observations; however the precise magnitudes of the observed effects are not reproduced by the calculations. For the Au-Pd heterophase boundary semi-quantitative agreement is obtained between the experiments and the calculations (performed using EAM potentials and Molecular Statics). Finally, in the Ag-Cu [Sigma] 4/5 system, strong X-ray scattering is observed on the BDL, and is correlated with surprisingly large atomic displacements in this boundary; fairly good agreement is obtained with computer simulated structures. We conclude with speculations on the usefulness of the simple dislocation model in the Ag-Cu [001] twist system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31311/1/0000220.pd

Design and Administration of Patient-Centred Outcome Measures: The Perspectives of Children and Young People with Life-Limiting or Life-Threatening Conditions and Their Family Members

BACKGROUND: Self-reported health data from children with life-limiting conditions is rarely collected. To improve acceptability and feasibility of child and family-centred outcome measures for children, they need to be designed in a way that reflects preferences, priorities and abilities. OBJECTIVES: The aim was to identify preferences for patient-reported outcome measure design (recall period, response format, length, administration mode) to improve the feasibility, acceptability, comprehensibility and relevance of a child and family-centred outcome measure, among children with life-limiting conditions and their family members. METHOD: A semi-structured qualitative interview study seeking the perspectives of children with life-limiting conditions, their siblings and parents on measure design was conducted. Participants were purposively sampled and recruited from nine UK sites. Verbatim transcripts were analysed using framework analysis. RESULTS: A total of 79 participants were recruited: 39 children aged 5–17 years (26 living with a life-limiting condition; 13 healthy siblings) and 40 parents (of children aged 0–17 years). Children found a short recall period and a visually appealing measure with ten questions or fewer most acceptable. Children with life-limiting conditions were more familiar with using rating scales such as numeric and Likert than their healthy siblings. Children emphasised the importance of completing the measure alongside interactions with a healthcare professional to enable them to talk about their responses. While parents assumed that electronic completion methods would be most feasible and acceptable, a small number of children preferred paper. CONCLUSIONS: This study demonstrates that children with life-limiting conditions can engage in communicating preferences regarding the design of a patient-centred outcome measure. Where possible, children should be given the opportunity to participate in the measure development process to enhance acceptability and uptake in clinical practice. Results of this study should be considered in future research on outcome measure development in children

Built-in and induced polarization across LaAlO3_3/SrTiO3_3 heterojunctions

Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. In ultra thin film form however the polar crystals are expected to remain stable without necessitating surface reconstructions, yet the built-in potential has eluded observation. Here we present evidence of a built-in potential across polar \lao ~thin films grown on \sto ~substrates, a system well known for the electron gas that forms at the interface. By performing electron tunneling measurements between the electron gas and a metallic gate on \lao ~we measure a built-in electric field across \lao ~of 93 meV/\AA. Additionally, capacitance measurements reveal the presence of an induced dipole moment near the interface in \sto, illuminating a unique property of \sto ~substrates. We forsee use of the ionic built-in potential as an additional tuning parameter in both existing and novel device architectures, especially as atomic control of oxide interfaces gains widespread momentum.Comment: 6 pages, 4 figures. Submitted to Nature physics on May 1st, 201

Integrating Comprehensive Geriatric Assessment for people with COPD and frailty starting pulmonary rehabilitation: the Breathe Plus feasibility trial protocol.

One in five people with COPD also lives with frailty. People living with both COPD and frailty are at increased risk of poorer health and outcomes, and face challenges to completing pulmonary rehabilitation. Integrated approaches that are adapted to the additional context of frailty are required. The aim of the present study is to determine the feasibility of conducting a randomised controlled trial of an integrated Comprehensive Geriatric Assessment for people with COPD and frailty starting pulmonary rehabilitation. This is a multicentre, mixed-methods, assessor-blinded, randomised, parallel group, controlled feasibility trial ("Breathe Plus"; ISRCTN13051922). We aim to recruit 60 people aged ≥50 with both COPD and frailty referred for pulmonary rehabilitation. Participants will be randomised 1:1 to receive usual pulmonary rehabilitation, or pulmonary rehabilitation with an additional Comprehensive Geriatric Assessment. Outcomes (physical, psycho-social and service use) will be measured at baseline, 90 days and 180 days. We will also collect service and trial process data, and conduct qualitative interviews with a sub-group of participants and staff. We will undertake descriptive analysis of quantitative feasibility outcomes (recruitment, retention, missing data, blinding, contamination, fidelity), and framework analysis of qualitative feasibility outcomes (intervention acceptability and theory, outcome acceptability). Recommendations on progression to a full trial will comprise integration of quantitative and qualitative data, with input from relevant stakeholders. This study has been approved by a UK Research Ethics Committee (ref.: 19/LO/1402). This protocol describes the first study testing the feasibility of integrating a Comprehensive Geriatric Assessment alongside pulmonary rehabilitation, and testing this intervention within a mixed-methods randomised controlled trial

A framework for complexity in palliative care: A qualitative study with patients, family carers and professionals

Background:Palliative care patients are often described as complex but evidence on complexity is limited. We need to understand complexity, including at individual patient-level, to define specialist palliative care, characterise palliative care populations and meaningfully compare interventions/outcomes.Aim:To explore palliative care stakeholders’ views on what makes a patient more or less complex and insights on capturing complexity at patient-level.Design:In-depth qualitative interviews, analysed using Framework analysis.Participants/setting:Semi-structured interviews across six UK centres with patients, family, professionals, managers and senior leads, purposively sampled by experience, background, location and setting (hospital, hospice and community).Results:65 participants provided an understanding of complexity, which extended far beyond the commonly used physical, psychological, social and spiritual domains. Complexity included how patients interact with family/professionals, how services’ respond to needs and societal perspectives on care. ‘Pre-existing’, ‘cumulative’ and ‘invisible’ complexity are further important dimensions to delivering effective palliative and end-of-life care. The dynamic nature of illness and needs over time was also profoundly influential. Adapting Bronfenbrenner’s Ecological Systems Theory, we categorised findings into the microsystem (person, needs and characteristics), chronosystem (dynamic influences of time), mesosystem (interactions with family/health professionals), exosystem (palliative care services/systems) and macrosystem (societal influences). Stakeholders found it acceptable to capture complexity at the patient-level, with perceived benefits for improving palliative care resource allocation.Conclusion:Our conceptual framework encompasses additional elements beyond physical, psychological, social and spiritual domains and advances systematic understanding of complexity within the context of palliative care. This framework helps capture patient-level complexity and target resource provision in specialist palliative care

Polymorphism in M(H2PO2)3 (M = V, Al, Ga) compounds with the perovskite-related ReO3 structure.

Trivalent metal hypophosphites with the general formula M(H2PO2)3 (M = V, Al, Ga) adopt the ReO3 structure, with each compound displaying two structural polymorphs. High-pressure synchrotron X-ray studies reveal a pressure-driven phase transition in Ga(H2PO2)3 that can be understood on the basis of ab initio thermodynamics

Towards person-centered quality care for children with life-limiting and life-threatening illness: self-reported symptoms, concerns and priority outcomes from a multi-country qualitative study

Abstract Background: Paediatric life-limiting and life-threatening conditionslife-limiting conditions place significant strain on children, families and health systems. Given high service use among this population, it is essential that care addresses their main symptoms and concerns. Aim: This study aimed to identify the symptoms, concerns, and other outcomes that matter to children with life-limiting conditions and their families in sub-Saharan Africa.Setting and participants: Cross-sectional qualitative study in Kenya, Namibia, South Africa and Uganda. Children/caregivers of children aged 0-17 years with life-limiting conditions were purposively sampled by age, sex, and diagnosis. Children aged 7 and above self-reported; caregiver proxies reported for children below 7 and those aged 7 and above unable to self-report.Results: 120 interviews were conducted with children with life-limiting conditions (n=61 age range 7-17 years), and where self-report was not possible caregivers (n=59) of children (age range 0-17). Conditions included advanced HIV (22%), cancer (19%), heart disease (16%) endocrine, blood and immune disorders (13%), neurological conditions (12%), sickle cell anaemia (10%) and renal disease (8%). Outcomes identified included: physical concerns – pain and symptom distress; psycho-social concerns – family and social relationships, ability to engage with age-appropriate activities (e.g., play, school attendance); existential concerns – worry about death, and loss of ambitions,health care quality– child- and adolescent-friendly services. Priority psycho-social concerns and health service factors varied by age.Conclusion: This study bridges an important knowledge gap regarding symptoms, concerns and outcomes that matter to children living with life-limiting conditions and their families and informs service development and evaluation

The development and cognitive testing of the positive outcomes HIV PROM: a brief novel patient-reported outcome measure for adults living with HIV

Background People living with HIV experience burdensome multidimensional symptoms and concerns requiring person-centred care. Routine use of patient reported outcome measures can improve outcomes. There is no brief patient reported outcome measure (PROM) that currently reflects the breadth of concerns for people living with HIV. This study aimed to develop and cognitively test a brief novel patient reported outcome measure for use within routine adult HIV care– the “Positive Outcomes” HIV PROM. Methods Development followed the COSMIN taxonomy and guidance for relevance and comprehensiveness, and Rothrock guidance on development of valid patient reported outcome measures. The Positive Outcomes HIV PROM was developed by a steering group (people living with HIV, HIV professionals and health services researchers) using findings from a previously reported qualitative study of priority outcomes for people living with HIV. The prototype measure was cognitively tested with a purposive sample of people living with HIV. Results The Positive Outcomes HIV PROM consists of 23 questions (22 structured, and one open question) informed by the priorities of key stakeholders (n = 28 people living with HIV, n = 21 HIV professionals and n = 8 HIV commissioners) to ensure face and content validity, and refined through cognitive testing (n = 6 people living with HIV). Cognitive testing demonstrated high levels of acceptability and accessibility. Conclusions The Positive Outcomes HIV PROM is the first brief patient reported outcome measure reflecting the diverse needs of people living with HIV designed specifically for use in the clinical setting to support patient assessment and care, and drive service quality improvement. It is derived from primary data on the priority outcomes for people living with HIV and is comprehensive and acceptable. Further psychometric testing is required to ensure reliability and responsiveness