Understanding oxygen evolution mechanisms by tracking charge flow at the atomic level.

Current classifications of oxygen evolution catalysts are based on energy levels of the clean catalysts. It is generally asserted that a LOM-catalyst can only follow LOM chemistry in each electron transfer step and that there can be no mixing between AEM and LOM steps without an external trigger. We use ab initio theory to track the charge flow of the water-on-catalyst system and show that the position of water orbitals is pivotal in determining whether an electron transfer step is water dominated oxidation (WDO), lattice-oxygen dominated oxidation (LoDO), or metal dominated oxidation (MDO). Microscopic photo-catalytic pathways of TiO2 (110), a material whose lattice oxygen bands lie above the metal bands, show that viable OER pathways follow either all AEM steps or mixed AEM-LOM steps. The results provide a correct description of redox chemistries at the atomic level and advance our understanding of how water-splitting catalysts produce desorbed oxygen.

Effectiveness and cost-effectiveness of a progressive, individualised walking and education programme for prevention of low back pain recurrence in adults: study protocol for the WalkBack randomised controlled trial.

INTRODUCTION: Low back pain (LBP) is recognised globally as a prevalent, costly and disabling condition. Recurrences are common and contribute to much of the burden of LBP. Current evidence favours exercise and education for prevention of LBP recurrence, but an optimal intervention has not yet been established. Walking is a simple, widely accessible, low-cost intervention that has yet to be evaluated. This randomised controlled trial (RCT) aims to establish the effectiveness and cost-effectiveness of a progressive and individualised walking and education programme (intervention) for the prevention of LBP recurrences in adults compared with no treatment (control). METHODS AND ANALYSIS: A pragmatic, two-armed RCT comparing walking and education (n=349) with a no treatment control group (n=349). Inclusion criteria are adults recovered from an episode of non-specific LBP within the last 6 months. Those allocated to the intervention group will receive six sessions (three face to face and three telephone delivered) with a trained physiotherapist to facilitate a progressive walking programme and education over a 6-month period. The primary outcome will be days to first recurrence of an episode of activity-limiting LBP. The secondary outcomes include days to recurrence of an episode of LBP, days to recurrence of an episode of LBP leading to care seeking, disability and quality of life measured at 3, 6, 9 and 12 months and costs associated with LBP recurrence. All participants will be followed up monthly for a minimum of 12 months. The primary intention-to-treat analysis will assess difference in survival curves (days to recurrence) using the log-rank statistic. The cost-effectiveness analysis will be conducted from the societal perspective. ETHICS AND DISSEMINATION: Approved by Macquarie University Human Research Ethics Committee (Reference: 5201949218164, May 2019). Findings will be disseminated through publication in peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: ACTRN12619001134112.

Antibacterial and photocatalytic activity of TiO2 and ZnO nanomaterials in phosphate buffer and saline solution.

We studied antibacterial and photocatalytic activity of anatase TiO2 and ZnO in phosphate buffer and saline solution. We found that the different anions in the suspension medium (chloride and phosphate) significantly affected the following suspension properties: the stability of nanoparticle suspension, the release of metal ions from the nanoparticles, and the production of the reactive oxygen species by the nanoparticles. As a result, antibacterial activity and photocatalytic dye degradation were also affected. However, the effect of the suspension medium was different for ZnO and TiO2. Obtained results are discussed.