Influence of size and temperature on the phase stability and thermophysical properties of anatase TiO2 nanoparticles: molecular dynamics simulation

Nanoparticles have attracted the attention of researchers in a number of multidisciplinary fields as they possess enhanced structural and physical properties, which make them desirable to a wide range of industries. These enhancements have mostly been attributed to their large surface area-to-volume ratio. However, the effect of temperature on the structural and surface properties of nanoparticles of different sizes is still not well understood, an aspect addressed in the present work. Using molecular dynamics simulations, we have performed investigations on anatase TiO2 nanoparticles with sizes ranging between 2 and 6 nm and at different temperatures. Structural and surface properties including surface energies are reported for the different nanoparticle sizes, temperature and simulation time step. Comparisons of surface energies for the different nanoparticle sizes show that surface energy increases to a maximum(optimum value) especially for temperatures between 300 and 1,500 K, as the particle size increases after which no further significant increase is observed. Studies conducted on the change of final structure with respect to the initial structure of the particles, revealed that atomic structural disordering is more visible at the surface layer compared to the bulk or core of the final structure. Further studies conducted on the sphericity of the nanoparticles showed that the particles became less spherical with increase in temperature

Constraining volatile abundance in chondritic components

Accepted versio

A qualitative evaluation of occupational therapy-led work rehabilitation for people with inflammatory arthritis : perspectives of therapists and their line managers

Introduction: Occupational therapy-led work rehabilitation for employed people with inflammatory arthritis and work problems was piloted in five hospitals in the United Kingdom. This qualitative study explored the views of participating occupational therapists and their line managers about the work rehabilitation training received and conducting the intervention, with particular focus on the structured interview used, the Work Experience Survey – Rheumatic Conditions. Method: Face-to-face semi-structured interviews were conducted with occupational therapists (n¼9), followed by telephone interviews with their line managers (n¼2). Interviews were audio-recorded, transcribed verbatim and thematically analysed by three researchers to maximize validity. Results: The main themes emerging from the occupational therapists’ interviews were: varying levels of prior knowledge and experience of work rehabilitation, initial concerns about the feasibility of a lengthy work assessment in practice and increased confidence in delivering work rehabilitation as the study progressed. The line managers’ interviews generated themes around the positive impact of the work rehabilitation training the occupational therapists received, and changes in their practice. Conclusion: The Work Experience Survey – Rheumatic Conditions was considered a good choice of work assessment which can be implemented in practice. Once therapists had provided the work intervention several times, their confidence and skills increase

Thallium concentration and thallium isotope composition of lateritic terrains

Continental weathering plays a key role in modifying the geochemical budget of terrestrial reservoirs. Laterites are the products of extreme sub-aerial continental weathering. This study presents the first investigation of thallium (Tl) abundances and stable isotopic compositions of lateritic terrains. Two laterite profiles from India of differing protolith and age are studied. Thallium concentrations range between 7 and 244 ng/g for a basalt-based lateritic profile and 37–652 ng/g within a greywacke lateritic profile. The average Tl stable isotope composition of the two profiles is similar to many typical igneous materials, however, the intense tropical weathering causes a small but resolvable fractionation of Tl stable isotopes towards heavy values in the residual soils. The profiles are dominated by significant positive isotope excursions (reported as ε205Tl relative to standard NBS997) of +3.5 ± 0.5 2sd and +6.2 ± 0.5 2sd at the inferred palaeowater tables within both laterite profiles. These signatures likely reflect combined changes in redox state and mineralogy. Extensive mineral dissolution under through-flowing fluids alongside the formation of new phases such as phyllosilicates and Mn- and Fe-oxides and hydroxides likely account for some of the Tl mobilisation, sorption and coprecipitation. In the case of laterites, the formation of the new phases and role of surface sorption likely contribute to stable Tl isotope fractionation. The identification of strong isotope excursions at inferred palaeowater tables encourages future research to determine specific mineral phases that may drive significant fractionation of Tl stable isotopes. This study showcases the magnitude of natural variation possible in terrestrial soils. Such information is key to the nascent application of Tl isotope compositions as tracers of anthropogenic pollution

Boron-Doped Diamond Dual-Plate Deep-Microtrench Device for Generator-Collector Sulfide Sensing

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.A BDD-BDD dual-plate microtrench electrode with 6μm inter-electrode spacing is investigated using generator-collector electrochemistry and shown to give microtrench depth-dependent sulfide detection down to the μM levels. The effect of the microtrench depth is compared for a "shallow" 44 μm and a "deep" 180μm microtrench and linked to the reduction of oxygen to hydrogen peroxide which interferes with sulfide redox cycling. With a deeper microtrench and a fixed collector potential at -1.4V vs. SCE, two distinct redox cycling potential domains are observed at 0.0V vs. SCE (2-electron) and at 1.1V vs. SCE (6-electron).F. M. and A. J. G. thank EPSRC for financial support (EP/I028706/1)

Preclinical characterization of zuranolone (SAGE-217), a selective neuroactive steroid GABAA receptor positive allosteric modulator

Zuranolone (SAGE-217) is a novel, synthetic, clinical stage neuroactive steroid GABAA receptor positive allosteric modulator designed with the pharmacokinetic properties to support oral daily dosing. In vitro, zuranolone enhanced GABAA receptor current at nine unique human recombinant receptor subtypes, including representative receptors for both synaptic (γ subunit-containing) and extrasynaptic (δ subunit-containing) configurations. At a representative synaptic subunit configuration, α1β2γ2, zuranolone potentiated GABA currents synergistically with the benzodiazepine diazepam, consistent with the non-competitive activity and distinct binding sites of the two classes of compounds at synaptic receptors. In a brain slice preparation, zuranolone produced a sustained increase in GABA currents consistent with metabotropic trafficking of GABAA receptors to the cell surface. In vivo, zuranolone exhibited potent activity, indicating its ability to modulate GABAA receptors in the central nervous system after oral dosing by protecting against chemo-convulsant seizures in a mouse model and enhancing electroencephalogram β-frequency power in rats. Together, these data establish zuranolone as a potent and efficacious neuroactive steroid GABAA receptor positive allosteric modulator with drug-like properties and CNS exposure in preclinical models. Recent clinical data support the therapeutic promise of neuroactive steroid GABAA receptor positive modulators for treating mood disorders; brexanolone is the first therapeutic approved specifically for the treatment of postpartum depression. Zuranolone is currently under clinical investigation for the treatment of major depressive episodes in major depressive disorder, postpartum depression, and bipolar depression

Tandem quadruplication of HMA4 in the zinc (Zn) and cadmium (Cd) hyperaccumulator noccaea caerulescens

Zinc (Zn) and cadmium (Cd) hyperaccumulation may have evolved twice in the Brassicaceae, in Arabidopsis halleri and in the Noccaea genus. Tandem gene duplication and deregulated expression of the Zn transporter, HMA4, has previously been linked to Zn/Cd hyperaccumulation in A. halleri. Here, we tested the hypothesis that tandem duplication and deregulation of HMA4 expression also occurs in Noccaea. A Noccaea caerulescens genomic library was generated, containing 36,864 fosmid pCC1FOSTM clones with insert sizes ~20–40 kbp, and screened with a PCR-generated HMA4 genomic probe. Gene copy number within the genome was estimated through DNA fingerprinting and pooled fosmid pyrosequencing. Gene copy numbers within individual clones was determined by PCR analyses with novel locus specific primers. Entire fosmids were then sequenced individually and reads equivalent to 20-fold coverage were assembled to generate complete whole contigs. Four tandem HMA4 repeats were identified in a contiguous sequence of 101,480 bp based on sequence overlap identities. These were flanked by regions syntenous with up and downstream regions of AtHMA4 in Arabidopsis thaliana. Promoter-reporter b-glucuronidase (GUS) fusion analysis of a NcHMA4 in A. thaliana revealed deregulated expression in roots and shoots, analogous to AhHMA4 promoters, but distinct from AtHMA4 expression which localised to the root vascular tissue. This remarkable consistency in tandem duplication and deregulated expression of metal transport genes between N. caerulescens and A. halleri, which last shared a common ancestor >40 mya, provides intriguing evidence that parallel evolutionary pathways may underlie Zn/Cd hyperaccumulation in Brassicaceae

We are all teacher educators now: understanding school-based teacher educators in times of change in England

Within the context of the European Commission’s recent policy gaze on teacher education (European Commission, Improving teacher quality: The EU agenda – lifelong learning: policies and programme. Brussels, April 2010, EAC.B.2. D (2010) PSH, 2010; European Commission, Supporting teacher educators for better learning outcomes. European Commission, Brussels, 2013; European Commission, Strengthening teaching in Europe: new evidence from teachers compiled by Eurydice and CRELL, June 2015. Available from: http://ec.europa.eu/education/library/policy/teaching-profession-practices_en.pdf, 2015), this chapter contributes to an improved understanding of the hybrid, poly-contextualised identities of school-based teacher educators. At a time of systemic change in the education systems of many countries, teachers in schools are increasingly being asked to be responsible for the education and training of future teachers. Within the English backdrop of a rapidly changing landscape for teacher education, we present initial findings from a small-scale study exploring, through interview data, how the knowledge bases and identities of two groups of insiders, university and school-based teacher educators, were perceived by those hybrid teacher educators (Zeichner 2010) working in schools. Our findings reveal differences in school-based teacher educators’ views on their work and the work of university-based teacher educators, school-based teacher educators’ views on the role educational research has in the work they do and the ways in which different professional pathways (e.g. occupational/university; primary/secondary) influence views on what it means to be a teacher educator

ER and HER2 expression are positively correlated in HER2 non-overexpressing breast cancer

PMCID: PMC3446380This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Biphasic investigation of contact mechanics in natural human hips during activities

The aim of this study was to determine the cartilage contact mechanics and the associated fluid pressurisation of the hip joint under eight daily activities, using a three-dimensional finite element hip model with biphasic cartilage layers and generic geometries. Loads with spatial and temporal variations were applied over time and the time-dependent performance of the hip cartilage during walking was also evaluated. It was found that the fluid support ratio was over 90% during the majority of the cycles for all the eight activities. A reduced fluid support ratio was observed for the time at which the contact region slid towards the interior edge of the acetabular cartilage, but these occurred when the absolute level of the peak contact stress was minimal. Over 10 cycles of gait, the peak contact stress and peak fluid pressure remained constant, but a faster process of fluid exudation was observed for the interior edge region of the acetabular cartilage. The results demonstrate the excellent function of the hip cartilage within which the solid matrix is prevented from high levels of stress during activities owing to the load shared by fluid pressurisation. The findings are important in gaining a better understanding of the hip function during daily activities, as well as the pathology of hip degeneration and potential for future interventions. They provide a basis for future subject-specific biphasic investigations of hip performance during activities