1,340 research outputs found
Addressing patient treatment preferences at trial recruitment.
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Data on the theoretical X-Ray attenuation and transmissions for lithium-ion battery cathodes
This article reports the data required for planning attenuation-based X-ray characterisation e.g. X-ray computed tomography (CT), of lithium-ion (Li-ion) battery cathodes. The data reported here is to accompany a co-submitted manuscript (10.1016/j.matdes.2020.108585 [1]) which compares two well-known X-ray attenuation data sources: Henke et al. and Hubbell et al., and applies methodology reported by Reiter et al. to extend this data towards the practical characterisation of prominent cathode materials. This data may be used to extend beyond the analysis reported in the accompanying manuscript, and may aid in the applications for other materials, not limited to Li-ion batteries
Theoretical transmissions for X-ray computed tomography studies of lithium-ion battery cathodes
X-ray computed tomography (CT) has emerged as a powerful tool for the 3D characterisation of materials. However, in order to obtain a useful tomogram, sufficient image quality should be achieved in the radiographs before reconstruction into a 3D dataset. The ratio of signal- and contrast-to-noise (SNR and CNR, respectively) quantify the image quality and are largely determined by the transmission and detection of photons that have undergone useful interactions with the sample. Theoretical transmission can be predicted if only a few variables are known: the material chemistry and penetrating thickness e.g. the particle diameter. This work discusses the calculations required to obtain transmission values for various Li(NiXMnYCoZ)O2 (NMC) lithium-ion battery cathodes. These calculations produce reference plots for quick assessment of beam parameters when designing an experiment. This is then extended to the theoretical material thicknesses for optimum image contrast. Finally, the theoretically predicted transmission is validated through comparison to experimentally determined values. These calculations are not exclusive to NMC, nor battery materials, but may be applied as a framework to calculate various sample transmissions and therefore may aid in the design and characterisation of numerous materials
Inverting the handedness of circularly polarized luminescence from light-emitting polymers using film thickness
The emission of circularly polarized light is central to many applications, including data storage, optical quantum computation, biosensing, environmental monitoring, and display technologies. An emerging method to induce (chiral) circularly polarized (CP) electroluminescence from the active layer of polymer light-emitting diodes (polymer OLEDs; PLEDs) involves blending achiral polymers with chiral small-molecule additives, where the handedness/sign of the CP light is controlled by the absolute stereochemistry of the small molecule. Through the in-depth study of such a system we report an interesting chiroptical property: the ability to tune the sign of CP light as a function of active layer thickness for a fixed enantiomer of the chiral additive. We demonstrate that it is possible to achieve both efficient (4.0 cd/A) and bright (8000 cd/m2) CP-PLEDs, with high dissymmetry of emission of both left-handed (LH) and right-handed (RH) light, depending on thickness (thin films, 110 nm: gEL = 0.51, thick films, 160 nm: gEL = -1.05, with the terms "thick" and "thin" representing the upper and lower limits of the thickness regime studied), for the same additive enantiomer. We propose that this arises due to an interplay between localized CP emission originating from molecular chirality and CP light amplification or inversion through a chiral medium. We link morphological, spectroscopic, and electronic characterization in thin films and devices with theoretical studies in an effort to determine the factors that underpin these observations. Through the control of active layer thickness and device architecture, this study provides insights into the mechanisms that result in CP luminescence and high performance from CP-PLEDs, as well as demonstrating new opportunities in CP photonic device design
Correlative electrochemical acoustic time-of-flight spectroscopy and X-ray imaging to monitor the performance of single-crystal and polycrystalline NMC811/Gr lithium-ion batteries
LiNixMnyCozO2 (NMC) electrodes typically consist of anisotropic single-crystal primary particles aggregated to form polycrystalline secondary particles. Electrodes composed of polycrystalline NMC particles have a comparatively high gravimetric capacity and good rate capabilities but do not perform as well as single crystal equivalents in terms of volumetric energy density and cycling stability. This has prompted research into well-dispersed single-crystalline NMC products as an alternative solution for high-energy-density batteries. Here, for the first time known to the authors, electrochemical acoustic time-of-flight (EA-ToF) spectroscopy has been shown to be effective in distinguishing between Li-ion batteries composed of either single-crystal NMC811 (SC-NMC811) or polycrystalline NMC811 (PC-NMC811) electrodes. Cells composed of PC-NMC811 electrodes had a higher degree of gas evolution compared to cells containing SC-NMC811 electrodes. Cells composed of PC-NMC811 electrodes also underwent larger changes in the acoustic signal's time-of-flight (ToF) during constant current cycling at a range of C-rates indicating expansion, fracture or dislocation of the reflective interfaces inside the cell. In addition, X-ray computed tomography (X-ray CT) has been used to confirm significant morphological differences between SC-NMC811 electrodes and PC-NMC811 electrodes including the electrode's particle size distribution (PSD) that is suggested to have an effect on acoustic signal interaction with these electrode interfaces
A pragmatic randomised controlled trial of hydrotherapy and land exercises on overall well being and quality of life in rheumatoid arthritis
Background \ud
Hydrotherapy is highly valued by people with rheumatoid arthritis yet few studies have compared the benefits of exercises in heated water against exercises on land. In particular, data on quality of life is rarely reported. This is especially important because patients treated with hydrotherapy often report an enhanced sense of well-being. We report a randomised controlled trial in which we compared the effects of hydrotherapy with exercises on land on overall response to treatment, physical function and quality of life in patients with rheumatoid arthritis. \ud
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Methods \ud
One hundred and fifteen patients with RA were randomised to receive a weekly 30-minute session of hydrotherapy or similar exercises on land for 6 weeks. Our primary outcome was a self-rated global impression of change – a measure of treatment effect on a 7-point scale ranging from 1(very much worse) to 7 (very much better) assessed immediately on completion of treatment. Secondary outcomes including EuroQol health related quality of life, EuroQol health status valuation, HAQ, 10 metre walk time and pain scores were collected at baseline, after treatment and 3 months later. Binary outcomes were analysed by Fisher's exact test and continuous variables by Wilcoxon or Mann-Whitney tests. \ud
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Results \ud
Baseline characteristics of the two groups were comparable. Significantly more patients treated with hydrotherapy (40/46, 87%) were much better or very much better than the patients treated with land exercise (19/40, 47.5%), p < 0.001 Fisher's exact test. Eleven patients allocated land exercise failed to complete treatment compared with 4 patients allocated hydrotherapy (p = 0.09). Sensitivity analyses confirmed an advantage for hydrotherapy if we assumed non-completers would all not have responded (response rates 70% versus 38%; p < 0.001) or if we assumed that non-completers would have had the same response as completers (response rates 82% versus 55% p = 0.002). Ten metre walk time improved after treatment in both cases (median pre-treatment time for both groups combined 10.9 seconds, post-treatment 9.1 s, and 3 months later 9.6 s). There was however no difference between treatment groups. Similarly there were no significant differences between groups in terms of changes to HAQ, EQ-5D utility score, EQ VAS and pain VAS. \ud
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Conclusion \ud
Patients with RA treated with hydrotherapy are more likely to report feeling much better or very much better than those treated with land exercises immediately on completion of the treatment programme. This perceived benefit was not reflected by differences between groups in 10-metre walk times, functional scores, quality of life measures and pain scores
'What vision?': experiences of Team members in a community service for adults with intellectual disabilities.
BACKGROUND: In the UK, the closure of 'long-stay' hospitals was accompanied by the development of community teams (CTs) to support people with intellectual disabilities (IDs) to live in community settings. The self-reported experiences of staff working in such teams have been neglected. METHODS: Focusing on a single county-wide service, comprising five multi-disciplinary and inter-agency CTs, we measured perceptions among the health care and care management Team members of (1) their personal well-being; (2) the functioning of their team; and (3) the organisation's commitment to quality, and culture. RESULTS: Almost three-quarters of the questionnaires were returned (73/101; 72%). The scores of health care practitioners and care managers were very similar: (1) the MBI scores of more than half the respondents were 'of concern'; (2) similarly, almost four in ten respondents' scores on the Vision scale of the TCI were 'of concern'; (3) the perceived commitment to quality (QIIS-II Part 2) was uncertain; and (4) the organisational culture (QIIS-II, Part 1) was viewed as primarily hierarchical. DISCUSSION: The perceived absence of a vision for the service, combined with a dominant culture viewed by its members as strongly focussed on bureaucracy and process, potentially compromises the ability of these CTs to respond proactively to the needs of people with IDs. Given the changes in legislation, policy and practice that have taken place since CTs were established, it would be timely to revisit their role and purpose.We are grateful to all our participants in the IDP, without whom the study could not have taken place, to Professor Eivor Oborn (Warwick Business School) for her insights in the development of the study. Funding was provided by the NIHR’s Collaboration for Health Research & Care (CLAHRC) for Cambridgeshire & Peterborough. The preparation of the paper was funded by the NIHR’s CLAHRC East of England (ICHC, KAW, AJH, AL, EJ, APW). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.This is the author accepted manuscript. The final version is available from Wiley via https://doi.org/10.1111/jir.1231
Taxonomy, biostratigraphy, and phylogeny of Oligocene and lower Miocene Dentoglobigerina and Globoquadrina
The taxonomy, phylogeny, and biostratigraphy of
Oligocene and lower Miocene Dentoglobigerina
and Globoquadrina are reviewed. Because of the
discovery of spine holes in various species assigned
to these genera, the entire group is now considered to
have been fully or sparsely spinose in life and hence
part of Family Globigerinidae. One new species,
Dentoglobigerina eotripartita Pearson, Wade, and
Olsson n. sp., is named. Dentoglobigerina includes
forms with and without umbilical teeth and species
for which the presence or absence of a tooth is a
variable feature. A significant finding has been the
triple synonymy of Globigerina tripartita Koch,
Globigerina rohri Bolli, and Globoquadrina dehiscens
praedehiscens Blow, which greatly simplifies part of
the taxonomy. The genus Globoquadrina is restricted
to its type species, Globigerina dehiscens Chapman and
others. The following species from the time interval
of interest are regarded as valid: Dentoglobigerina altispira (Cushman and Jarvis), Dentoglobigerina
baroemoenensis (LeRoy), Dentoglobigerina
binaiensis (Koch), Dentoglobigerina eotripartita
Pearson, Wade, and Olsson n. sp., Dentoglobigerina
galavisi (Bermúdez), Dentoglobigerina
globosa (Bolli), Dentoglobigerina globularis
(Bermúdez), Dentoglobigerina juxtabinaiensis
Fox and Wade, Dentoglobigerina larmeui (Akers),
Dentoglobigerina prasaepis (Blow), Dentoglobigerina
pseudovenezuelana (Blow and Banner),
Dentoglobigerina sellii (Borsetti), Dentoglobigerina
taci Pearson and Wade, Dentoglobigerina tapuriensis
(Blow and Banner), Dentoglobigerina tripartita
(Koch), Dentoglobigerina venezuelana (Hedberg),
and Globoquadrina dehiscens (Chapman, Parr,
and Collins). The genus Dentoglobigerina also
comprises other Neogene/Quaternary species not
listed, including the living species Dentoglobigerina
cf. conglomerata (Schwager)
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