2,265 research outputs found
Tailoring non-stoichiometry and mixed ionic-electronic conductivity in nanostructured Pr-substituted ceria
High concentrations of mobile oxygen vacancies are crucial for devices such as SOFCs, SOECs, gas permeation membranes, and sensors, while for other applications such as ferroelectrics and piezoelectrics, oxygen vacancies are detrimental. Hence there is great interest in tailoring the oxygen vacancy concentration and mobility for given materials. Changes in oxygen non-stoichiometry also result in dilation of the crystal lattice, known as chemical expansion, and therefore there is a coupling between the electrical, chemical, and mechanical properties known as electro-chemo-mechanical coupling. Confined systems, such as thin films, are being investigated as a way to tailor the non-stoichiometry and transport properties of materials, shifting the paradigm away from searching for new materials or compositions.
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Designing Optimal Perovskite Structure for High Ionic Conduction.
Solid-oxide fuel/electrolyzer cells are limited by a dearth of electrolyte materials with low ohmic loss and an incomplete understanding of the structure-property relationships that would enable the rational design of better materials. Here, using epitaxial thin-film growth, synchrotron radiation, impedance spectroscopy, and density-functional theory, the impact of structural parameters (i.e., unit-cell volume and octahedral rotations) on ionic conductivity is delineated in La0.9 Sr0.1 Ga0.95 Mg0.05 O3- δ . As compared to the zero-strain state, compressive strain reduces the unit-cell volume while maintaining large octahedral rotations, resulting in a strong reduction of ionic conductivity, while tensile strain increases the unit-cell volume while quenching octahedral rotations, resulting in a negligible effect on the ionic conductivity. Calculations reveal that larger unit-cell volumes and octahedral rotations decrease migration barriers and create low-energy migration pathways, respectively. The desired combination of large unit-cell volume and octahedral rotations is normally contraindicated, but through the creation of superlattice structures both expanded unit-cell volume and large octahedral rotations are experimentally realized, which result in an enhancement of the ionic conductivity. All told, the potential to tune ionic conductivity with structure alone by a factor of ≈2.5 at around 600 °C is observed, which sheds new light on the rational design of ion-conducting perovskite electrolytes
Erratum:Publisher Correction: Identification of 371 genetic variants for age at first sex and birth linked to externalising behavior (Nature human behaviour (2021))
Shared decision-making for psychiatric medication : A mixed-methods evaluation of a UK training programme for service users and clinicians
This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (http://www.creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).Background: Shared decision making (SDM) is recognised as a promising strategy to enhance good collaboration between clinicians and service users, yet it is not practised regularly in mental health. Aims: Develop and evaluate a novel training programme to enhance SDM in psychiatric medication management for service users, psychiatrists and care co-ordinators. Methods: The training programme design was informed by existing literature and local stakeholders consultations. Parallel group-based training programmes on SDM process were delivered to community mental health service users and providers. Evaluation consisted of quantitative measures at baseline and 12-month follow-up, post-programme participant feedback and qualitative interviews. Results: Training was provided to 47 service users, 35 care-coordinators and 12 psychiatrists. Participant feedback was generally positive. Statistically significant changes in service users’ decisional conflict and perceptions of practitioners’ interactional style in promoting SDM occurred at the follow-up. Qualitative data suggested positive impacts on service users’ and care co-ordinators confidence to explore medication experience, and group-based training was valued. Conclusions: The programme was generally acceptable to service users and practitioners. This indicates the value of conducting a larger study and exploring application for non-medical decisions.Peer reviewedFinal Published versio
Inhibition of IL-34 Unveils Tissue-Selectivity and Is Sufficient to Reduce Microglial Proliferation in a Model of Chronic Neurodegeneration
The proliferation and activation of microglia, the resident macrophages in the brain,
is a hallmark of many neurodegenerative diseases such as Alzheimer’s disease (AD)
and prion disease. Colony stimulating factor 1 receptor (CSF1R) is critically involved
in regulating microglial proliferation, and CSF1R blocking strategies have been recently
used to modulate microglia in neurodegenerative diseases. However, CSF1R is broadly
expressed by many cell types and the impact of its inhibition on the innate immune
system is still unclear. CSF1R can be activated by two independent ligands, CSF-1 and
interleukin 34 (IL-34). Recently, it has been reported that microglia development and
maintenance depend on IL-34 signaling. In this study, we evaluate the inhibition of IL-34
as a novel strategy to reduce microglial proliferation in the ME7 model of prion disease.
Selective inhibition of IL-34 showed no effects on peripheral macrophage populations in
healthy mice, avoiding the side effects observed after CSF1R inhibition on the systemic
compartment. However, we observed a reduction in microglial proliferation after IL-34
inhibition in prion-diseased mice, indicating that microglia could be more specifically
targeted by reducing IL-34. Overall, our results highlight the challenges of targeting the
CSF1R/IL34 axis in the systemic and central compartments, important for framing any
therapeutic effort to tackle microglia/macrophage numbers during brain disease
Siderophore-Mediated Zinc Acquisition Enhances Enterobacterial Colonization of the Inflamed Gut
Zinc is an essential cofactor for bacterial metabolism, and many Enterobacteriaceae express the zinc transporters ZnuABC and ZupT to acquire this metal in the host. However, the probiotic bacterium Escherichia coli Nissle 1917 (or “Nissle”) exhibits appreciable growth in zinc-limited media even when these transporters are deleted. Here, we show that Nissle utilizes the siderophore yersiniabactin as a zincophore, enabling Nissle to grow in zinc-limited media, to tolerate calprotectin-mediated zinc sequestration, and to thrive in the inflamed gut. We also show that yersiniabactin’s affinity for iron or zinc changes in a pH-dependent manner, with increased relative zinc binding as the pH increases. Thus, our results indicate that siderophore metal affinity can be influenced by the local environment and reveal a mechanism of zinc acquisition available to commensal and pathogenic Enterobacteriaceae
Current experiences and educational preferences of general practitioners and staff caring for people with dementia living in residential facilities
<p>Abstract</p> <p>Background</p> <p>Residential care is important for older adults, particularly for those with advanced dementia and their families. Education interventions that achieve sustainable improvement in the care of older adults are critical to quality care. There are few systematic data available regarding the educational needs of Residential Care Facility (RCF) staff and General Practitioners (GPs) relating to dementia, or the sustainability of educational interventions. We sought to determine participation in dementia education, perceived levels of current knowledge regarding dementia, perceived unmet educational needs, current barriers, facilitators and preferences for dementia education.</p> <p>Methods</p> <p>A mixed methods study design was utilised. A survey was distributed to a convenience sample of general practitioners, and staff in 223 consecutive residential care facilities in Perth, Western Australia. Responses were received from 102 RCF staff working in 10 facilities (out of 33 facilities who agreed to distribute the survey) and 202 GPs (19% of metropolitan GPs). Quantitative survey data were summarised descriptively and chi squared statistics were used to analyse the distribution of categorical variables. Qualitative data were collected from general practitioners, staff in residential care facilities and family carers of people with dementia utilizing individual interviews, surveys and focus groups. Qualitative data were analysed thematically.</p> <p>Results</p> <p>Among RCF staff and GPs attending RCF, participation in dementia education was high, and knowledge levels generally perceived as good. The individual experiences and needs of people with dementia and their families were emphasised. Participants identified the need for a person centred philosophy to underpin educational interventions. Limited time was a frequently mentioned barrier, especially in relation to attending dementia care education. Perceived educational needs relating to behaviours of concern, communication, knowledge regarding dementia, aspects of person centred care, system factors and the multidisciplinary team were consistently and frequently cited. Small group education which is flexible, individualized, practical and case based was sought.</p> <p>Conclusion</p> <p>The effectiveness and sustainability of an educational intervention based on these findings needs to be tested. In addition, future interventions should focus on supporting cultural change to facilitate sustainable improvements in care.</p
Hundreds of variants clustered in genomic loci and biological pathways affect human height
Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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