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Practitioners’ views about effective mental health and well-being support for post-16 students attending special school
No full textExperimental investigation on the fatigue crack growth behaviour of Q420C
No full textThe lack of test data on the fatigue crack growth behaviour of Q420C steel affects its application in the field of wind power engineering. To fill this gap, this paper carried out an experimental study and theoretical analysis of the fatigue crack propagation behaviour of Q420C steel under constant amplitude. Six compact tension specimens were separately tested under six loading conditions comprising two maximum loads (𝐹𝑚𝑎𝑥=8 𝑘𝑁 𝑜𝑟 10 𝑘𝑁) and three load ratios (𝑅=0.1,0.3,𝑜𝑟 0.5). The Back-Face Strain method was used to calculate the crack length, and a complete cycle of strain values was recorded for every 1 mm of crack extension. The crack growth rate and crack opening load were calculated according to the ASTM E647-15. The test results show that for the two crack growth rate calculation methods given by the ASTM E647-15, the secant method provides large discrete results, while the incremental polynomial method can obtain a relatively smooth rate curve. In addition, for the incremental polynomial method, the normalisation of the number of cycles in the ASTM E647-15 should not be used to achieve acceptable results. The rate curves of Q420C steel show a clear load ratio effect, for the same stress intensity factor range Δ𝐾, the higher the load ratio, the faster the crack grows. Quantitative analysis of the effect of load ratios has shown that two-parameter models based on 'unified theory', such as Walker’s model, can accurately describe the effect of load ratios. However, the theory of plasticity-induced crack closure cannot account for the effect of load ratios, as the crack opening load 𝐹𝑜𝑝 is less than the minimum load 𝐹𝑚𝑖𝑛 for load ratios greater than 0.1. Finally, a comparison is carried out against the predictions by BS7910; results verify the applicability of BS7910 to Q420C steel material and demonstrate the different degrees of conservatism of all recommended design curves in BS7910
Second coordination sphere effects on the mechanistic pathways for dioxygen activation by a ferritin: involvement of a Tyr radical and the identification of a cation binding site
No full textFerritins are ubiquitous diiron enzymes involved in iron(II) detoxification and oxidative stress responses and can act as metabolic iron stores. The overall reaction mechanisms of ferritin enzymes are still unclear, particularly concerning the role of the conserved, near catalytic center Tyr residue. Thus, we carried out a computational study of a ferritin using a large cluster model of well over 300 atoms including its first- and second-coordination sphere. The calculations reveal important insight into the structure and reactivity of ferritins. Specifically, the active site Tyr residue delivers a proton and electron in the catalytic cycle prior to iron(II) oxidation. In addition, the calculations highlight a likely cation binding site at Asp65, which through long-range electrostatic interactions, influences the electronic configuration and charge distributions of the metal center. The results are consistent with experimental observations but reveal novel detail of early mechanistic steps that lead to an unusual mixedvalent iron(III)-iron(II) center
A five-spin supramolecule for simulating quantum decoherence of Bell states
No full textWe report a supramolecule that contains five spins of two different types, and with, crucially, two different and predictable interaction energies between the spins. The supramolecule is characterised and the interaction energies demonstrated by EPR spectroscopy. Based on the measured parameters we propose experiments that would allow this designed supramolecule to be used to simulate quantum decoherence in maximally entangled Bell states that could be used in quantum teleportation
Scaleability of dielectric susceptibility ϵzz with the number of layers and additivity of ferroelectric polarization in van der Waals semiconductors
No full textWe study the dielectric response of few layered crystals of various transition metal dichalcogenides (TMDs) and hexagonal Boron Nitride (hBN). We showed that the out-of-plane polarizability of a multilayer crystal (which characterizes response to the external displacement field) scales linearly with the number of layers, αNL zz = Nα1L zz , independently of the stacking configuration in the film. We also established additivity of ferroelectric polarizations of consecutive interfaces in case when such interfaces have broken inversion symmetry. Then we used the obtained data of monolayer α1L zz to calculate the values of the dielectric susceptibilities for semiconductor TMDs and hBN bulk crystals
Bridging disconnected networks of first and second lines of biologic therapies in rheumatoid arthritis with registry data: Bayesian evidence synthesis with target trial emulation
No full textObjective: We aim to utilise real world data in evidence synthesis to optimise an evidence base for the effectiveness of biologic therapies in rheumatoid arthritis in order to allow for evidence on first-line therapies to inform second-line effectiveness estimates.Study design and setting: We use data from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR-RA) to supplement RCT evidence obtained from the literature, by emulating target trials of treatment sequences to estimate treatment effects in each line of therapy. Treatment effects estimates from the target trials inform a bivariate network meta-analysis (NMA) of first and second-line treatments.Results: Summary data were obtained from 21 trials of biologic therapies including 2 for second-line treatment and results from six emulated target trials of both treatment lines. Bivariate NMA resulted in a decrease in uncertainty around the effectiveness estimates of the second-line therapies, when compared to the results of univariate NMA, and allowed for predictions of treatment effects not evaluated in second-line RCTs.Conclusion: Bivariate NMA provides effectiveness estimates for all treatments in first- and second-line, including predicted effects in second-line where these estimates did not exist in the data. This novel methodology may have further applications, for example for bridging networks of trials in children and adults
The influence of social support, financial status and lifestyle on the disparity between inflammation and disability in rheumatoid arthritis
No full textObjectives: To investigate how social support, financial status and lifestyle influence the development of excess disability in rheumatoid arthritis (RA).Methods: Data came from the Étude et Suivi des Polyarthrites Indifférenciées Récentes (ESPOIR) cohort study of people with RA. A previous analysis identified groups with similar inflammation trajectories but markedly different disability over 10 years; those in the higher disability trajectory groups were defined as having “excess disability”. Participants self-reported data on contextual factors (social support, financial situation, lifestyle) and completed patient reported outcome measures (PROMs; pain, fatigue, anxiety, depression) at baseline. The direct effect of the contextual factors on excess disability and the effect mediated by PROMs was assessed using structural equation models. Findings were validated within two independent datasets (Norfolk Arthritis Register [NOAR], Early Rheumatoid Arthritis Network [ERAN]).Results: Of 538 included ESPOIR participants (mean age [standard deviation (SD)]: 48.3 [12.2] years, 79.2% women), 200 (37.2%) were in the excess disability group. Less social support (β 0.17 [95% CI 0.08, 0.26]), worse financial situation (β 0.24 [95% CI 0.14, 0.34]), less exercise (β 0.17 [95% CI 0.09, 0.25]) and less education (β 0.15 [95% CI 0.06, 0.23]) were associated with excess disability group membership; smoking, alcohol consumption and body mass index were not. Fatigue and depression mediated a small proportion of these effects. Similar results were seen in NOAR and ERAN. Conclusions: Greater emphasis is needed on the economic and social context of people with RA at presentation; these factors might influence disability over the following decade. <br/
Effects of Sensor Design on the Performance of Wearable Sweat Monitors
No full textWearable sweat sensors are rapidly emerging for continuous and noninvasive monitoring of ‘wet’ parameters not included in current commercial wearables. This paper investigates the optimization of screen printed sweat sensors, intended to ultimately be compatible with large scale, roll-to-roll, fabrication. Sweat sensors containing Na+, K+ ion selective electrodes and pH sensing elements were screen printed on polyethylene naphthalate films with different electrode array designs. For sensing Na+ ions, a PEDOT:PSS transducer layer was found to effectively improve the sensor performance, showing an up to 32% sensitivity enhancement of up to 113.3mV/decade. Large working electrode sensing area was found to play an important role in achieving high electrical sensitivity, and the position of the electrodes influenced the individual sensor performance. These findings provide a solid foundation for an optimized development on wearable sweat sensors
