Oxygen-tolerant proton reduction catalysis: Much O<inf>2</inf> about nothing?

This perspective summarises strategies for avoiding adverse effects of O2 on H2-evolving enzymatic systems, molecular synthetic catalysts and catalytic surfaces.Financial support from the EPSRC (EP/H00338X/2), the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and National Foundation for Research, Technology and Development), and the OMV Group is gratefully acknowledged.This is the final version of the article. It first appeared from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C5EE01167

Proton reduction by molecular catalysts in water under demanding atmospheres.

The electrocatalytic proton reduction activity of a Ni bis(diphosphine) (NiP) and a cobaloxime (CoP) catalyst has been studied in water in the presence of the gaseous inhibitors O2 and CO. CoP shows an appreciable tolerance towards O2, but its activity suffers severely in the presence of CO. In contrast, NiP is strongly inhibited by O2, but produces H2 under high CO concentrations.Financial support from the EPSRC (EP/H00338X/2), the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and National Foundation for Research, Technology and Development), and the OMV Group is gratefully acknowledged.Originally published by The Royal Society of Chemistry, Chem. Commun., 2014, 50, 15995, http://dx.doi.org/10.1039/C4CC06159

Reversible interconversion of CO2 and formate by a molybdenum-containing formate dehydrogenase.

CO2 and formate are rapidly, selectively, and efficiently interconverted by tungsten-containing formate dehydrogenases that surpass current synthetic catalysts. However, their mechanism of catalysis is unknown, and no tractable system is available for study. Here, we describe the catalytic properties of the molybdenum-containing formate dehydrogenase H from the model organism Escherichia coli (EcFDH-H). We use protein film voltammetry to demonstrate that EcFDH-H is a highly active, reversible electrocatalyst. In each voltammogram a single point of zero net current denotes the CO2 reduction potential that varies with pH according to the Nernst equation. By quantifying formate production we show that electrocatalytic CO2 reduction is specific. Our results reveal the capabilities of a Mo-containing catalyst for reversible CO2 reduction and establish EcFDH-H as an attractive model system for mechanistic investigations and a template for the development of synthetic catalysts.This is the final version. It was first published by ACS at http://pubs.acs.org/doi/abs/10.1021/ja508647

Photocatalytic Formic Acid Conversion on CdS Nanocrystals with Controllable Selectivity for H2 or CO.

Formic acid is considered a promising energy carrier and hydrogen storage material for a carbon-neutral economy. We present an inexpensive system for the selective room-temperature photocatalytic conversion of formic acid into either hydrogen or carbon monoxide. Under visible-light irradiation (λ>420 nm, 1 sun), suspensions of ligand-capped cadmium sulfide nanocrystals in formic acid/sodium formate release up to 116±14 mmol H2 g(cat)(-1) h(-1) with >99% selectivity when combined with a cobalt co-catalyst; the quantum yield at λ=460 nm was 21.2±2.7%. In the absence of capping ligands, suspensions of the same photocatalyst in aqueous sodium formate generate up to 102±13 mmol CO g(cat)(-1) h(-1) with >95% selectivity and 19.7±2.7% quantum yield. H2 and CO production was sustained for more than one week with turnover numbers greater than 6×10(5) and 3×10(6), respectively.This work was supported by the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and the National Foundation for Research, Technology and Development), the OMV Group, the EPSRC (EP/H00338X/2 to ER), the Isaac Newton Trust, the German Research Foundation (MFK), and the Advanced Institute for Materials Research-Cambridge Joint Research Centre (KLO). XPS spectra were obtained at the National EPSRC XPS User's Service (NEXUS) at Newcastle University, an EPSRC Mid-Range Facility.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/anie.20150623

A Poly(cobaloxime)/Carbon Nanotube Electrode: Freestanding Buckypaper with Polymer-Enhanced H2-Evolution Performance.

A freestanding H2-evolution electrode consisting of a copolymer-embedded cobaloxime integrated into a multiwall carbon nanotube matrix by π-π interactions is reported. This electrode is straightforward to assemble and displays high activity towards hydrogen evolution in near-neutral pH solution under inert and aerobic conditions, with a cobalt-based turnover number (TON(Co)) of up to 420. An analogous electrode with a monomeric cobaloxime showed less activity with a TON(Co) of only 80. These results suggest that, in addition to the high surface area of the porous network of the buckypaper, the polymeric scaffold provides a stabilizing environment to the catalyst, leading to further enhancement in catalytic performance. We have therefore established that the use of a multifunctional copolymeric architecture is a viable strategy to enhance the performance of molecular electrocatalysts.We acknowledge support by the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and National Foundation for Research, Technology and Development), the OMV Group, the EPSRC, the BBSRC (Grant BB/K010220/1) and the Woolf Fisher Trust in New Zealand and the Cambridge Trusts. We also thank the National EPSRC XPS User’s Service (NEXUS) at Newcastle University, UK.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/anie.20151137

MS in South Asians in England: early disease onset and novel pattern of myelin autoimmunity.

BACKGROUND: Epidemiological studies describe a latitude gradient for increased MS prevalence and a preponderance of disease in Caucasian individuals. However, individuals from other ethnic backgrounds and low-risk regions can acquire a raised risk through migration. Nearly a fifth of the London population is of Asian/Asian-British origin and a significant proportion of referrals are from this group. METHODS: We investigated whether there were differences in timing, presentation, severity, and immunology of disease (with respect to CD4 myelin epitope recognition) between individuals in London with MS who were either of S. Asian or Caucasian origin. Individuals of S. Asian origin with MS were compared with healthy S. Asian controls, individuals with MS and of Caucasian origin and Caucasian controls. RESULTS: Age at MS onset is significantly lower in the S. Asian group, attributable to earlier onset specifically in UK-born individuals, though clinical presentation is similar. Analysis of CD4 autoimmunity to myelin antigens shows disease in S. Asian individuals to encompass recognition of novel epitopes; immunity to MBP116-130 in S. Asian individuals was highly disease-specific. CONCLUSIONS: These findings emphasize the need to define disease profiles across ethnicities and identify environmental triggers conferring acquired risk. Such findings must inform choices for immunotherapeutic interventions suitable for all, across ethnicities

Medication-Overuse Headache: Update on Management

Long-term frequent use of acute pain medication for the treatment of headaches has paradoxically been shown to increase the frequency of headaches. So-called medication-overuse headache (MOH) is particularly problematic in patients with migraine who overuse triptans and opioids. Prevention through education remains the most important management strategy. Once established, MOH can be difficult to treat. Although complete or near-complete withdrawal of acute pain medication for 8–12 weeks has been shown to benefit most patients, this can be hard to achieve. The use of OnabotulinumtoxinA and drugs that target the calcitonin gene-related peptide system for the prevention of migraines have been shown to benefit patients with MOH. Furthermore, the use of novel acute pain medication for migraines, including Gepants and Ditans, which do not cause MOH, are likely to improve patient outcomes. In this review article we examine the following: the burden of MOH; who develops MOH; the pathophysiological mechanisms; and the treatment strategies

Dynamics of Knowledge Leverage in ERP Implementation

This paper reports the results of an in-depth investigation of the knowledge management (KM) activities of an ERP implementation project within a dynamic business setting. Using a case study approach, this research examines the challenges faced by the ERP project team with respect to KM and the effectiveness of KM strategies. In addition to gaining insights into typical KM activities within the ERP project lifecycle, the research reveals that major barriers for effective KM are created by external business changes and the business process life cycle. These changes trigger a chain reaction resulting in the weak performance of key KM activities such as knowledge capture, sharing and retention. The need for a comprehensive array of KM initiatives that are capable of managing such changes by recognizing the dynamics of all three life cycles is highlighted

The Use of Squiggling: A Play Technique as a Diagnostic Aid in the Assessment of Secondary School-Age Children with Asperger Syndrome

Winnicott’s (1968, 1993) play technique squiggling was piloted as a measure of creative thinking abilities and a potential diagnostic aid in the assessment of Asperger syndrome. The internal consistency and inter-rater reliability of squiggling was found to be acceptable. Mixed results were found between the six subscales in terms of concurrent validity with the Torrance Tests of Creative Thinking (TTCT: Torrance, Bal & Safter, 2008). Squiggling subscales Elaboration and Imagination showed signs of psychometric strength. However, Fluency and Originality require revision. Concurrent validity of the subscales Flexibility and Integration were not established. A matched-participants design enabled testing of hypothesised differences in creative thinking abilities with children with Asperger syndrome using the TTCT (Torrance et al., 2008): Abstractedness, Fluency, Originality, Integration, Elaboration, Resistance to Premature Foreclosure and Flexibility. Children with Asperger syndrome demonstrated a significantly higher level of elaboration and abstract imagination in their drawings relative to a comparison group of typically-developing children matched on age, visual motor integration ability and non-verbal IQ. Findings indicate partial support for the Weak Central Coherence Theory (Shah and Frith, 1983) and Leslie’s (1987) Meta-Representational Deficit hypothesis. Children with Asperger syndrome demonstrated understanding and expression of abstract concepts as graphical representations, thereby supporting their use in clinical assessments and interventions. No support was found for the Executive Dysfunction Theory (Pennington & Ozonoff, 1996) or for the Hyper-Systemising Theory (Baron-Cohen, 2006). Some limitations include the heterogeneity of the clinical group, and the possible confounding effects of verbal intellectual abilities, extrinsic rewards and performance anxiety. Major strengths of the study include a successful matching procedure and the finding of group differences with large effect sizes on particular creative thinking abilities