Characterisation of surfaces modified through self-assembled monolayers and click chemistry

Different approaches to surface modification were investigated in this work on gold, glassy carbon, multi-walled carbon nanotube paper and on single-walled carbon nanotubes adsorbed on glassy carbon. These approaches include electrochemical grafting, electropolymerisation, click chemistry, axial ligation, adsorption and self-assembled monolayers. The modified surfaces were characterised using a variety of techniques; predominantly electrochemistry, scanning electrochemical microscopy and X-ray photoelectron spectroscopy. For the formation of self-assembled monolayers on gold, four new manganese(III) phthalocyanines (1a-d), octa-substituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups were synthesized and characterised. X-ray photoelectron spectroscopy was used to show the formation of a sulphur-gold bond. A number of approaches using 4-azidoaniline (2a) combined with azide-alkyne click chemistry and electrochemistry were also used to anchor ferrocene and pyridine moieties on to the carbon surfaces, including direct in situ diazotation and grafting, electropolymerisation, and the synthesis of the diazonium salt followed by grafting. Iron phthalocyanine was linked to the pyridine-clicked surfaces through axial ligation, where the strong axial bond formed by the interaction between the central metal and the lone pair of the nitrogen in the pyridine group resulted in stable modified electrodes. The potential of these surfaces for the detection of analytes such as thiocyanate, hydrazine and sulphite are briefly shown as well. This work also describes for the first time the possibility of performing local micro-electrochemical grafting of a gold substrate by 4-azidobenzenediazonium (2b) using scanning electrochemical microscopy in a single and simple one step approach, without complications from adsorption

Characterisation of surfaces modified through self-assembled monolayers and click chemistry

Different approaches to surface modification were investigated in this work on gold, glassy carbon, multi-walled carbon nanotube paper and on single-walled carbon nanotubes adsorbed on glassy carbon. These approaches include electrochemical grafting, electropolymerisation, click chemistry, axial ligation, adsorption and self-assembled monolayers. The modified surfaces were characterised using a variety of techniques; predominantly electrochemistry, scanning electrochemical microscopy and X-ray photoelectron spectroscopy. For the formation of self-assembled monolayers on gold, four new manganese(III) phthalocyanines (1a-d), octa-substituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups were synthesized and characterised. X-ray photoelectron spectroscopy was used to show the formation of a sulphur-gold bond. A number of approaches using 4-azidoaniline (2a) combined with azide-alkyne click chemistry and electrochemistry were also used to anchor ferrocene and pyridine moieties on to the carbon surfaces, including direct in situ diazotation and grafting, electropolymerisation, and the synthesis of the diazonium salt followed by grafting. Iron phthalocyanine was linked to the pyridine-clicked surfaces through axial ligation, where the strong axial bond formed by the interaction between the central metal and the lone pair of the nitrogen in the pyridine group resulted in stable modified electrodes. The potential of these surfaces for the detection of analytes such as thiocyanate, hydrazine and sulphite are briefly shown as well. This work also describes for the first time the possibility of performing local micro-electrochemical grafting of a gold substrate by 4-azidobenzenediazonium (2b) using scanning electrochemical microscopy in a single and simple one step approach, without complications from adsorption

Paramedic views regarding clinical research in out of hospital cardiac arrest

Background: The success of pre-hospital research relies on positive engagement from paramedics. Without adequate participation and protocol compliance trials will not succeed. Aims: To seek feedback from paramedics about trial participation and determine their preferences regarding a future large-scale research study. Methods: Paramedics participating in REVIVE-Airways were sent a feedback questionnaire according to their study allocation. Findings: 99% of respondents were willing to participate in a further large-scale trial. Participants offered recommendations for future pre-hospital trials. Conclusion: There was strong support for further clinical trials of alternative airway management strategies during OHCA. Paramedics welcome opportunities to participate in research and receive feedback about trial progress and patient outcomes

Electrochemical, spectroscopic and microscopic studies of new manganese phthalocyanine complexes in solution and as self-assembled monolayers on gold

Four new manganese(III) phthalocyanines (3a–d), octasubstituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups, respectively, were synthesized. Their specific electrochemical, spectroscopic and microscopic properties in solution and as self-assembled monolayers on gold were characterized. The UV-vis spectra confirmed red-shifted Q bands for all the complexes, due to the effect of the central metal and the electron-donating substituents. Three redox couples were visible during cyclic voltammetry studies for the four complexes, and spectroelectrochemistry confirmed the couples as corresponding to MnIIIPc-2/MnIIPc-2 (II) (metal reduction), MnIIPc-2/MnIIPc-3 (III) (ring reduction) and MnIIIPc-1/MnIIIPc-2 (I) (ring oxidation). Electrochemistry was also used to determine the blocking characteristics of the MnPc self-assembled monolayers on gold, which proved to be highly dependent on the type of substituent. Other methods of characterization included Raman spectroscopy, atomic force and scanning electrochemical microscopy analyses of the SAMs

Layer by Layer Electrode Surface Functionalisation Using Carbon Nanotubes, Electrochemical Grafting of Azide‐Alkyne Functions and Click Chemistry

Ferrocene was covalently bonded to a layer of adsorbed single-walled carbon nanotubes on a glassy carbon electrode surface using electrochemical grafting and click chemistry. Grafting of the 4-azidobenzenediazonium salt onto the surface was accomplished by electrochemical reduction. The surface-bound azide groups, with the use of a copper(I) catalyst, were reacted with ethynylferrocene to form covalent 1,2,3-triazole bonds by click chemistry. This layer by layer construction of the electrode surface results in stable electrodes by combining good electrical conductivity and increased surface area of the nanotubes with the versatility of the Sharpless click reaction

Gender differences in perceptions of psoriatic arthritis disease impact, management, and physician interactions: results from a global patient survey

Introduction: We evaluated the impact of gender on disease severity, health-related quality of life (HRQoL), treatment management, and patient–healthcare professional (HCP) interactions from the perspectives of patients with psoriatic arthritis (PsA). Methods: Data were collected from a global online patient survey conducted by The Harris Poll (November 2, 2017 to March 12, 2018). Eligible patients were aged ≥ 18 years, with a self-reported diagnosis of PsA for > 1 year, had visited a rheumatologist/dermatologist in the past 12 months, and had reported previously using ≥ 1 conventional synthetic or biologic disease-modifying antirheumatic drug. Data were stratified by gender and analyzed descriptively, inferentially by binomial (chi-square) tests, and by multivariate logistic regression models. Results: Data from 1286 patients who participated were included: 52% were female, 48% were male. Varying perceptions of disease severity between males and females were indicated by differences in symptoms leading to a diagnosis of PsA, and in symptoms reported despite treatment; more females than males reported joint tenderness, skin patches/plaques, and enthesitis. More females than males reported a major/moderate impact of PsA on their physical activity and emotional/mental well-being. Reasons for switching medication differed between genders, with more females switching because they perceived their medication to not be effective enough related to their joint symptoms. More females than males were very satisfied with their communication with their rheumatologist and were more likely to discuss the impact of PsA on their daily lives, their treatment satisfaction, and treatment goals with their rheumatologist. Conclusions:Patients’ perceptions of the impact of PsA on HRQoL, treatment management, and interactions with HCPs varied between males and females. More females than males reported major/moderate physical and emotional impacts of PsA. When treating patients, it is important for HCPs to consider the potential impact of gender on patients’ experience of PsA and its symptoms. Graphical plain language summary available for this article

4-Azidoaniline-based electropolymer as a building block for functionalisation of conductive surfaces

We propose in this work to compare three approaches using 4-azidoaniline combined with “click” chemistry and electrochemistry to anchor ferrocene moieties at glassy carbon surfaces. The immobilisation of a newly synthesised molecule, 4-(4-ferrocenyl-1H-1,2,3-triazol-1-yl)aniline, through direct electropolymerisation or via in situ diazotization followed by electrografting is studied by analysing the samples by XPS and electrochemistry

Mitigating Sulfidogenesis With Simultaneous Perchlorate and Nitrate Treatments

Sulfide biogenesis (souring) in oil reservoirs is an extensive and costly problem. Nitrate is currently used as a souring inhibitor but often requires high concentrations and yields inconsistent results. Recently, perchlorate has displayed promise as a more potent inhibitor in lab scale studies. However, combining the two treatments to determine synergy and effectiveness in a dynamic system has never been tested. Nitrate inhibits perchlorate consumption by perchlorate reducing bacteria, suggesting that the combined treatment may allow deeper penetration of the perchlorate into the reservoir matrix. Furthermore, the metabolic intermediates of perchlorate and nitrate reduction (nitrite and chlorite, respectively) are synergistic with the primary electron acceptors for inhibition of sulfate reduction. To assess the possible synergies between nitrate and perchlorate treatments, triplicate glass columns packed with pre-soured marine sediment were flushed with media containing sulfate and an inhibitor treatment [(i) perchlorate; (ii) nitrate; (iii) perchlorate and nitrate; or (iv) none]. Internal geochemistry and microbial community changes were monitored along the length of the columns during six phases of increasing treatment concentrations. In a final phase all treatments were removed. Sulfide production decreased in all treated columns in conjunction with increased inhibitor concentrations relative to the untreated control. Interestingly, the potency of the “mixed” treatment was additive relative to the individual treatments suggesting no interaction. Microbial community analyses indicated community shifts and clustering by treatment. The mixed treatment column community’s trajectory closely resembled that of the community found in the perchlorate only treatment, suggesting that perchlorate was the dominant control on the “mixed” community structure. In contrast, the nitrate and untreated column communities had unique trajectories. This study indicates that concurrent nitrate and perchlorate treatment is not more effective than perchlorate treatment alone but is more effective than nitrate treatment. As such, treatment decisions may be based on economic factors

Unconditional care in academic emergency departments

Recent news stories have explicitly stated that patients with symptoms of COVID-19 were "turned away" from emergency departments. This commentary addresses these serious allegations, with an attempt to provide the perspective of academic emergency departments (EDs) around the Nation. The overarching point we wish to make is that academic EDs never deny emergency care to any person

Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980–2015: a systematic analysis for the Global Burden of Disease Study 2015

Background Improving survival and extending the longevity of life for all populations requires timely, robust evidence on local mortality levels and trends. The Global Burden of Disease 2015 Study (GBD 2015) provides a comprehensive assessment of all-cause and cause-specific mortality for 249 causes in 195 countries and territories from 1980 to 2015. These results informed an in-depth investigation of observed and expected mortality patterns based on sociodemographic measures. Methods We estimated all-cause mortality by age, sex, geography, and year using an improved analytical approach originally developed for GBD 2013 and GBD 2010. Improvements included refinements to the estimation of child and adult mortality and corresponding uncertainty, parameter selection for under-5 mortality synthesis by spatiotemporal Gaussian process regression, and sibling history data processing. We also expanded the database of vital registration, survey, and census data to 14 294 geography–year datapoints. For GBD 2015, eight causes, including Ebola virus disease, were added to the previous GBD cause list for mortality. We used six modelling approaches to assess cause-specific mortality, with the Cause of Death Ensemble Model (CODEm) generating estimates for most causes. We used a series of novel analyses to systematically quantify the drivers of trends in mortality across geographies. First, we assessed observed and expected levels and trends of cause-specific mortality as they relate to the Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Second, we examined factors affecting total mortality patterns through a series of counterfactual scenarios, testing the magnitude by which population growth, population age structures, and epidemiological changes contributed to shifts in mortality. Finally, we attributed changes in life expectancy to changes in cause of death. We documented each step of the GBD 2015 estimation processes, as well as data sources, in accordance with Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, life expectancy from birth increased from 61·7 years (95% uncertainty interval 61·4–61·9) in 1980 to 71·8 years (71·5–72·2) in 2015. Several countries in sub-Saharan Africa had very large gains in life expectancy from 2005 to 2015, rebounding from an era of exceedingly high loss of life due to HIV/AIDS. At the same time, many geographies saw life expectancy stagnate or decline, particularly for men and in countries with rising mortality from war or interpersonal violence. From 2005 to 2015, male life expectancy in Syria dropped by 11·3 years (3·7–17·4), to 62·6 years (56·5–70·2). Total deaths increased by 4·1% (2·6–5·6) from 2005 to 2015, rising to 55·8 million (54·9 million to 56·6 million) in 2015, but age-standardised death rates fell by 17·0% (15·8–18·1) during this time, underscoring changes in population growth and shifts in global age structures. The result was similar for non-communicable diseases (NCDs), with total deaths from these causes increasing by 14·1% (12·6–16·0) to 39·8 million (39·2 million to 40·5 million) in 2015, whereas age-standardised rates decreased by 13·1% (11·9–14·3). Globally, this mortality pattern emerged for several NCDs, including several types of cancer, ischaemic heart disease, cirrhosis, and Alzheimer's disease and other dementias. By contrast, both total deaths and age-standardised death rates due to communicable, maternal, neonatal, and nutritional conditions significantly declined from 2005 to 2015, gains largely attributable to decreases in mortality rates due to HIV/AIDS (42·1%, 39·1–44·6), malaria (43·1%, 34·7–51·8), neonatal preterm birth complications (29·8%, 24·8–34·9), and maternal disorders (29·1%, 19·3–37·1). Progress was slower for several causes, such as lower respiratory infections and nutritional deficiencies, whereas deaths increased for others, including dengue and drug use disorders. Age-standardised death rates due to injuries significantly declined from 2005 to 2015, yet interpersonal violence and war claimed increasingly more lives in some regions, particularly in the Middle East. In 2015, rotaviral enteritis (rotavirus) was the leading cause of under-5 deaths due to diarrhoea (146 000 deaths, 118 000–183 000) and pneumococcal pneumonia was the leading cause of under-5 deaths due to lower respiratory infections (393 000 deaths, 228 000–532 000), although pathogen-specific mortality varied by region. Globally, the effects of population growth, ageing, and changes in age-standardised death rates substantially differed by cause. Our analyses on the expected associations between cause-specific mortality and SDI show the regular shifts in cause of death composition and population age structure with rising SDI. Country patterns of premature mortality (measured as years of life lost [YLLs]) and how they differ from the level expected on the basis of SDI alone revealed distinct but highly heterogeneous patterns by region and country or territory. Ischaemic heart disease, stroke, and diabetes were among the leading causes of YLLs in most regions, but in many cases, intraregional results sharply diverged for ratios of observed and expected YLLs based on SDI. Communicable, maternal, neonatal, and nutritional diseases caused the most YLLs throughout sub-Saharan Africa, with observed YLLs far exceeding expected YLLs for countries in which malaria or HIV/AIDS remained the leading causes of early death. Interpretation At the global scale, age-specific mortality has steadily improved over the past 35 years; this pattern of general progress continued in the past decade. Progress has been faster in most countries than expected on the basis of development measured by the SDI. Against this background of progress, some countries have seen falls in life expectancy, and age-standardised death rates for some causes are increasing. Despite progress in reducing age-standardised death rates, population growth and ageing mean that the number of deaths from most non-communicable causes are increasing in most countries, putting increased demands on health systems. Funding Bill & Melinda Gates Foundation.Bill & Melinda Gates Foundatio