An ARXPS and ERXPS study of quaternary ammonium and phosphonium ionic liquids: utilising a high energy Ag Lα’ X-ray source

Introduction Ionic liquid (IL) surface science has experienced rapid expansion in recent years. As such, a multitude of ultra-high vacuum (UHV) techniques have been used to probe the IL/vacuum interface including laboratory and synchrotron X-ray photoelectron spectroscopy (XPS), metastable impact electron spectroscopy (MIES), low energy ion scattering (LEIS), Rutherford backscattering (RBS) and neutral impact collision ion scattering spectroscopy (NICISS). To date, the vast majority of these studies have focused upon cyclic nitrogen-containing cations, particularly the 1-alkyl-3-methylimidazolium family, whereas acyclic cations including tetraalkylammonium and –phosphonium have been overlooked despite their potential use in a wide range of existing applications including heterogeneous catalysis, gas capture/separation, and nanoparticle formation

Tuning the Reactivity of TEMPO during Electrocatalytic Alcohol Oxidations in Room-Temperature Ionic Liquids

2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) is a promising, sustainable, metal-free mediator for oxidation of alcohols. In this contribution, we describe how the selectivity of TEMPO for electrocatalytic alcohol oxidations in room-temperature ionic liquids (RTILs) can be changed by design of the solvent medium. Cyclic voltammetry of TEMPO in a series of ammonium-, phosphonium-, and imidazolium-based RTILs reveals that the potential at which TEMPO is oxidized increases from 677 mV (vs. the potential of the decamethylferrocene/ decamethylferrocinium, dmFc/dmFc+, redox couple) to 788 mV as the H-bond basicity of the RTIL anions decreases. The increase in potential is accompanied by an increase in the rate constant for oxidation of benzyl alcohol from about 0.1 dm3 mol−1 s−1 to about 0.7 dm3 mol−1 s−1, demonstrating the ability to manipulate the reactivity of TEMPO by judicious choice of the RTIL anions. The rate of alcohol oxidation in a series of RTILs increases in the order 2-butanol < 1phenylethanol < octanol < benzyl alcohol, and the RTIL 1-octyl-3-methylmidazolium bis(trifluoromethanesulfonyl)imide ([NTf2]–) shows clear selectivity towards the oxidation of primary alcohols. In addition, the reaction kinetics and selectivity are better in [NTf2]–-based RTILs than in acetonitrile, often the solvent-of-choice in indirect alcohol electrooxidations. Finally, we demonstrate that electrolytic TEMPO-mediated alcohol oxidations can be performed using RTILs in a flow-electrolysis system, with excellent yields and reaction selectivity, demonstrating the opportunities offered by such systems

The impact of sulfur functionalisation on nitrogen-based ionic liquid cations

It has been demonstrated that bonding and interactions within ionic liquids (ILs) can be elegantly tuned by manipulation of structure and the the introduction of functional groups. Here we use XPS to investigate the impact of sulfur containing substituents on the electronic structure of a series N-based cations, all with a common anion, [NTf2]-. The experiments reveal complexity and perturbation of delocalised systems which cannot be easily interpretated by NMR and XPS alone, DFT provides critical insight into bonding and underpins the assignment of spectra and development of deconstruction models for each system studied

Severe mental illness and mortality and coronary revascularisation following a myocardial infarction:a retrospective cohort study

Background: Severe mental illness (SMI), comprising schizophrenia, bipolar disorder and major depression, is associated with higher myocardial infarction (MI) mortality but lower coronary revascularisation rates. Previous studies have largely focused on schizophrenia, with limited information on bipolar disorder and major depression, long-term mortality or the effects of either sociodemographic factors or year of MI. We investigated the associations between SMI and MI prognosis and how these differed by age at MI, sex and year of MI. Methods: We conducted a national retrospective cohort study, including adults with a hospitalised MI in Scotland between 1991 and 2014. We ascertained previous history of schizophrenia, bipolar disorder and major depression from psychiatric and general hospital admission records. We used logistic regression to obtain odds ratios adjusted for sociodemographic factors for 30-day, 1-year and 5-year mortality, comparing people with each SMI to a comparison group without a prior hospital record for any mental health condition. We used Cox regression to analyse coronary revascularisation within 30 days, risk of further MI and further vascular events (MI or stroke). We investigated associations for interaction with age at MI, sex and year of MI. Results: Among 235,310 people with MI, 923 (0.4%) had schizophrenia, 642 (0.3%) had bipolar disorder and 6239 (2.7%) had major depression. SMI was associated with higher 30-day, 1-year and 5-year mortality and risk of further MI and stroke. Thirty-day mortality was higher for schizophrenia (OR 1.95, 95% CI 1.64–2.30), bipolar disorder (OR 1.53, 95% CI 1.26–1.86) and major depression (OR 1.31, 95% CI 1.23–1.40). Odds ratios for 1-year and 5-year mortality were larger for all three conditions. Revascularisation rates were lower in schizophrenia (HR 0.57, 95% CI 0.48–0.67), bipolar disorder (HR 0.69, 95% CI 0.56–0.85) and major depression (HR 0.78, 95% CI 0.73–0.83). Mortality and revascularisation disparities persisted from 1991 to 2014, with absolute mortality disparities more apparent for MIs that occurred around 70 years of age, the overall mean age of MI. Women with major depression had a greater reduction in revascularisation than men with major depression. Conclusions: There are sustained SMI disparities in MI intervention and prognosis. There is an urgent need to understand and tackle the reasons for these disparities

The putative mevalonate diphosphate decarboxylase from Picrophilus torridus is in reality a mevalonate-3-kinase with high potential for bioproduction of isobutene

Mevalonate diphosphate decarboxylase (MVD) is an ATP-dependent enzyme that catalyzes the phosphorylation/decarboxylation of (R)-mevalonate-5-diphosphate to isopentenyl pyrophosphate in the mevalonate (MVA) pathway.MVD is a key enzyme in engineered metabolic pathways for bioproduction of isobutene, since it catalyzes the conversion of 3-hydroxyisovalerate (3-HIV) to isobutene, an important platform chemical. The putative homologue from Picrophilus torridus has been identified as a highly efficient variant in a number of patents, but its detailed characterization has not been reported. In this study, we have successfully purified and characterized the putative MVD from P. torridus. We discovered that it is not a decarboxylase per se but an ATP-dependent enzyme, mevalonate-3-kinase (M3K), which catalyzes the phosphorylation of MVA to mevalonate-3-phosphate. The enzyme’s potential in isobutene formation is due to the conversion of 3-HIV to an unstable 3-phosphate intermediate that undergoes consequent spontaneous decarboxylation to form isobutene. Isobutene production rates were as high as 507 pmol min-1 g cells-1 using Escherichia coli cells expressing the enzyme and 2,880 pmol min-1 mg protein-1 with the purified histidine-tagged enzyme, significantly higher than reported previously. M3K is a key enzyme of the novel MVA pathway discovered very recently in Thermoplasma acidophilum. We suggest that P. torridus metabolizes MVA by the same pathway

Continuous-Flow Alkene Metathesis: The Model Reaction of 1-Octene Catalyzed by Re2O7/alfa-Al2O3 with Supercritical CO2 as a Carrier

In the presence of Re2O7 supported on γ-Al2O3, the self-metathesis of 1-octene was conveniently carried out under continuous-flow (CF) conditions using supercritical CO2 (scCO2) as a carrier. This investigation allowed optimization of reaction parameters, the best values of which were found to be 100 °C and 90 bar, operating at flow rates of 0.05 and 1 mL min−1 for 1-octene and scCO2, respectively, the reaction proceeded with very good self-metathesis selectivity (>90%) and an average productivity of ∼0.24 mL tetradecene gRe −1 min−1 . Although the catalyst was completely deactivated after the first 100–150 min of reaction, it could be recycled for (at least) five subsequent reactions without any loss of performance. The results provided incontrovertible evidence that for the investigated reaction, scCO2was a superior carrier with respect to conventional liquids, such as toluene or n-hexane

Experimental measurement and prediction of ionic liquid ionisation energies

Ionic liquid (IL) valence electronic structure provides key descriptors for understanding and predicting IL properties. The ionisation energies of 60 ILs are measured and the most readily ionised valence state of each IL (the highest occupied molecular orbital, HOMO) is identified using a combination of X-ray photoelectron spectroscopy (XPS) and synchrotron resonant XPS. A structurally diverse range of cations and anions were studied. The cation gave rise to the HOMO for nine of the 60 ILs presented here, meaning it is energetically more favourable to remove an electron from the cation than the anion. The influence of the cation on the anion electronic structure (and vice versa) were established; the electrostatic effects are well understood and demonstrated to be consistently predictable. We used this knowledge to make predictions of both ionisation energy and HOMO identity for a further 516 ILs, providing a very valuable dataset for benchmarking electronic structure calculations and enabling the development of models linking experimental valence electronic structure descriptors to other IL properties, e.g. electrochemical stability. Furthermore, we provide design rules for the prediction of the electronic structure of ILs

Vascular endothelial growth factor-D is an independent prognostic factor in epithelial ovarian carcinoma.

We assessed the presence of vascular endothelial growth factor (VEGF)-C, VEGF-D and their receptor VEGFR-3 by immunohistochemistry in 59 epithelial ovarian carcinomas, 11 borderline tumours and 20 benign cystadenomas. VEGF-C and VEGF-D were generally expressed in tumour cells and also in endothelia adjacent to tumour nests which showed a strong staining for them. VEGFR-3 was expressed in lymphatic and vascular endothelial cells adjacent to tumour nests. Immunoreactivity was significantly more frequent as lesions progressed from a benign tumour to advanced carcinoma. A strong correlation was found between VEGF-C and VEGF-D detected in carcinoma and VEGFR-3 detected in neighbouring endothelial cells. Increased expression of VEGF-C, VEGF-D and VEGFR-3 was significantly associated with lymph node metastasis and peritoneal metastasis outside the pelvis. There was a significant correlation between the high levels of VEGF-C and VEGF-D proteins, and poor survival. The presence of VEGF-D was an independent prognostic indicator by multivariate analysis. We conclude that VEGF-C, VEGF-D and VEGFR-3 play an important role in lymphatic spread and intraperitoneal tumour development in ovarian carcinoma. Since VEGF-D was found to be an independent predictor of poor outcome, its measurement, together with other prognostic markers may improve prospective identification of patients with a poor prognosis

Recent outbreaks of infectious syphilis, United Kingdom, January 2012 to April 2014

Six outbreaks of infectious syphilis in the United Kingdom, ongoing since 2012, have been investigated among men who have sex with men (MSM) and heterosexual men and women aged under 25 years. Interventions included case finding and raising awareness among healthcare professionals and the public. Targeting at-risk populations was complicated as many sexual encounters involved anonymous partners. Outbreaks among MSM were influenced by the use of geospatial real-time networking applications that allow users to locate other MSM within close proximity