Accessible and sustainable Cu(0)-mediated radical polymerisation for the functionalisation of surfaces

Polymer brushes have great potential for use in functionalising surfaces due to their chemical and mechanical robustness, and wide variety of useful properties including antibacterial and antifouling behaviour. One such grafted polymer of interest is poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PMETAC), shown to have excellent antibacterial behaviour due to the presence of quaternary ammonium chloride groups (QACs). Previous studies have shown that increasing the density of QACs increases the efficacy of these surfaces, therefore the production of thick PMETAC brushes is highly desirable. Cu(0)-mediated radical polymerisation (CuRP) offers a simple route to the production of these surfaces. A movement towards more sustainable chemistry has led to research into polymerisations in environmentally benign solvent, with focus placed on recycled and easily accessible catalysts. In this study, the growth of PMETAC brushes up to 300 nm dry thickness (∼ 425 nm water-swollen thickness) is demonstrated, thicker than any previous report we have found for this polymer brush. Furthermore, tap water is used as a cheap and readily available solvent, with a catalyst derived from copper wire. The use of copper wire, compared to the commonly used CuBr2 catalyst, leads to thicker coatings which also display a lower swelling ratio, implying an increased grafting density. The protocol can be continuously cycled over a 7-day period without changing the monomer solution or catalyst, with numerous wafers being functionalised over the time period with no significant reduction in grafted amount. In addition, the polymerisation can be carried out in ambient (non-inert) conditions with no degassing steps, again without with significant detriment to grafting

In situ single walled carbon nanotube growth using a Q500 TGA

Using the Q500 Thermogravimetric Analyzer (TGA) it is demonstrated that it is possible to monitor the real time growth of Single Walled Carbon Nanotubes (SWCNTs) by Chemical Vapour Deposition (CVD) on SiO 2 supported Ni catalyst. The catalyst is made by first dissolving Ni(NO 3)·6H 2 O and SiO 2 in acetone and then allowing the acetone to evaporate. The resulting powder is then thermally decomposed in the Q500 TGA under an inert atmosphere of Ar(g) to generate SiO 2 supported NiO. The CH 4 (g) carbon precursor is then introduced, reducing the NiO to Ni and initiating the CVD growth of Carbon Nanotubes (CNTs). Thus both the formation of the catalyst and the growth of SWCNTs are monitored in real time by this method. The CVD grown carbon is confirmed as containing SWCNTs by Raman Spectroscopy. We believe this to be the first example of SWCNTs grown by CVD in a TGA

Measured solid state and subcooled liquid vapour pressures of nitroaromatics using Knudsen effusion mass spectrometry

Knudsen effusion mass spectrometry (KEMS) was used to measure the solid state saturation vapour pressure (PsatS) of a range of atmospherically relevant nitroaromatic compounds over the temperature range from 298 to 328 K. The selection of species analysed contained a range of geometric isomers and differing functionalities, allowing for the impacts of these factors on saturation vapour pressure (Psat) to be probed. Three subsets of nitroaromatics were investigated: nitrophenols, nitrobenzaldehydes and nitrobenzoic acids. The PsatS values were converted to subcooled liquid saturation vapour pressure (PsatL) values using experimental enthalpy of fusion and melting point values measured using differential scanning calorimetry (DSC). The PsatL values were compared to those estimated by predictive techniques and, with a few exceptions, were found to be up to 7 orders of magnitude lower. The large differences between the estimated PsatL and the experimental values can be attributed to the predictive techniques not containing parameters to adequately account for functional group positioning around an aromatic ring, or the interactions between said groups. When comparing the experimental PsatS of the measured compounds, the ability to hydrogen bond (H bond) and the strength of the H bond formed appear to have the strongest influence on the magnitude of the Psat, with steric effects and molecular weight also being major factors. Comparisons were made between the KEMS system and data from diffusion-controlled evaporation rates of single particles in an electrodynamic balance (EDB). The KEMS and the EDB showed good agreement with each other for the compounds investigated

Measured Solid State and Sub-Cooled Liquid Vapour Pressures of Benzaldehydes Using Knudsen Effusion Mass Spectrometry

Benzaldehydes are components of atmospheric aerosol that are poorly represented in current vapour pressure predictive techniques. In this study the solid state ( and sub-cooled liquid saturation vapour pressures ) were measured over a range of temperatures (298–328 K) for a chemically diverse group of benzaldehydes. The selected benzaldehydes allowed for the effects of varied geometric isomers and functionalities on saturation vapour pressure () to be probed. was measured using Knudsen effusion mass spectrometry (KEMS) and was obtained via a sub-cooled correction utilising experimental enthalpy of fusion and melting point values measured using differential scanning calorimetry (DSC). The strength of the hydrogen bond (H-bond) was the most important factor for determining when a H-bond was present and the polarisability of the compound was the most important factor when a H-bond was not present. Typically compounds capable of hydrogen bonding had 1 to 2 orders of magnitude lower than those that could not H-bond. The were compared to estimated values using three different predictive techniques (Nannoolal et al. vapour pressure method, Myrdal and Yalkowsky method, and SIMPOL). The Nannoolal et al. vapour pressure method and the Myrdal and Yalkowsky method require the use of a boiling point method to predict . For the compounds in this study the Nannoolal et al. boiling point method showed the best performance. All three predictive techniques showed less than an order of magnitude error in on average, however more significant errors were within these methods. Such errors will have important implications for studies trying to ascertain the role of these compounds on aerosol growth and human health impacts. SIMPOL predicted the closest to the experimentally determined values

Block copolymer synthesis in ionic liquid via polymerisation-induced self-assembly: A convenient route to gel electrolytes

We report for the first time a reversible addition–fragmentation chain transfer polymerisation-induced self-assembly (RAFT-PISA) formulation in ionic liquid (IL) that yields worm gels. A series of poly(2-hydroxyethyl methacrylate)-b-poly(benzyl methacrylate) (PHEMA-b-PBzMA) block copolymer nanoparticles were synthesised via RAFT dispersion polymerisation of benzyl methacrylate in the hydrophilic IL 1-ethyl-3-methyl imidazolium dicyanamide, [EMIM][DCA]. This RAFT-PISA formulation can be controlled to afford spherical, worm-like and vesicular nano-objects, with free-standing gels being obtained over a broad range of PBzMA core-forming degrees of polymerisation (DPs). High monomer conversions (≥96%) were obtained within 2 hours for all PISA syntheses as determined by 1H NMR spectroscopy, and good control over molar mass was confirmed by gel permeation chromatography (GPC). Nanoparticle morphologies were identified using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM), and further detailed characterisation was conducted to monitor rheological, electrochemical and thermal characteristics of the nanoparticle dispersions to assess their potential in future electronic applications. Most importantly, this new PISA formulation in IL facilitates the in situ formation of worm ionogel electrolyte materials at copolymer concentrations >4% w/w via efficient and convenient synthesis routes without the need for organic co-solvents or post-polymerisation processing/purification. Moreover, we demonstrate that the worm ionogels developed in this work exhibit comparable electrochemical properties and thermal stability to that of the IL alone, showcasing their potential as gel electrolytes

A health systems approach to critical care delivery in low-resource settings: a narrative review

There is a high burden of critical illness in low-income countries (LICs), adding pressure to already strained health systems. Over the next decade, the need for critical care is expected to grow due to ageing populations with increasing medical complexity; limited access to primary care; climate change; natural disasters; and conflict, adding pressure to the already strained health systems. In 2019, the 72nd World Health Assembly emphasised that an essential part of universal health coverage is improved access to effective emergency and critical care and to “ensure the timely and effective delivery of life-saving health care services to those in need”. In this narrative review we examine critical care capacity building in LICs from a health systems perspective. We conducted a systematic literature search, using the WHO health systems framework to structure findings within six core components or “building blocks”: 1) service delivery; 2) health workforce; 3) health information systems; 4) access to essential medicines and equipment; 5) financing; and 6) leadership and governance. We provide recommendations using this framework, derived from literature identified in our review. These recommendations are useful for policy makers, health service researchers and healthcare workers to inform critical care capacity building in low resource settings

Structured lifestyle education for people with schizophrenia, schizoaffective disorder and first-episode psychosis (STEPWISE): randomised controlled trial

Background Obesity is a major challenge for people with schizophrenia. Aims We assessed whether STEPWISE, a theory-based, group structured lifestyle education programme could support weight reduction in people with schizophrenia. Method In this randomised controlled trial (study registration: ISRCTN19447796), we recruited adults with schizophrenia, schizoaffective disorder or first-episode psychosis from ten mental health organisations in England. Participants were randomly allocated to the STEPWISE intervention or treatment as usual. The 12-month intervention comprised four 2.5 h weekly group sessions, followed by 2-weekly maintenance contact and group sessions at 4, 7 and 10 months. The primary outcome was weight change after 12 months. Key secondary outcomes included diet, physical activity, biomedical measures and patient-related outcome measures. Cost-effectiveness was assessed and a mixed-methods process evaluation was included. Results Between 10 March 2015 and 31 March 2016, we recruited 414 people (intervention 208, usual care 206) with 341 (84.4%) participants completing the trial. At 12 months, weight reduction did not differ between groups (mean difference 0.0 kg, 95% CI-1.6 to 1.7, P = 0.963); physical activity, dietary intake and biochemical measures were unchanged. STEPWISE was well-received by participants and facilitators. The healthcare perspective incremental cost-effectiveness ratio was £246 921 per quality-adjusted life-year gained. Conclusions Participants were successfully recruited and retained, indicating a strong interest in weight interventions; however, the STEPWISE intervention was neither clinically nor cost-effective. Further research is needed to determine how to manage overweight and obesity in people with schizophrenia

STEPWISE - STructured lifestyle Education for People WIth SchizophrEnia : a study protocol for a randomised controlled trial

BACKGROUND: People with schizophrenia are two to three times more likely to be overweight than the general population. The UK National Institute of Health and Care Excellence (NICE) recommends an annual physical health review with signposting to, or provision of, a lifestyle programme to address weight concerns and obesity. The purpose of this randomised controlled trial is to assess whether a group-based structured education programme can help people with schizophrenia to lose weight. METHODS: Design: a randomised controlled trial of a group-based structured education programme. SETTING: 10 UK community mental health trusts. PARTICIPANTS: 396 adults with schizophrenia, schizoaffective, or first-episode psychosis who are prescribed antipsychotic medication will be recruited. Participants will be overweight, obese or be concerned about their weight. INTERVENTION: participants will be randomised to either the intervention or treatment as usual (TAU). The intervention arm will receive TAU plus four 2.5-h weekly sessions of theory-based lifestyle structured group education, with maintenance contact every 2 weeks and 'booster' sessions every 3 months. All participants will receive standardised written information about healthy eating, physical activity, alcohol and smoking. OUTCOMES: the primary outcome is weight (kg) change at 1 year post randomisation. Secondary outcomes, which will be assessed at 3 and 12 months, include: the proportion of participants who maintained or reduced their weight; waist circumference; body mass index; objectively measured physical activity (wrist accelerometer); self-reported diet; blood pressure; fasting plasma glucose, lipid profile and HbA1c (baseline and 1 year only); health-related quality of life (EQ-5D-5L and RAND SF-36); (adapted) brief illness perception questionnaire; the Brief Psychiatric Rating Scale; the Client Service Receipt Inventory; medication use; smoking status; adverse events; depression symptoms (Patient Health Questionnaire-9); use of weight-loss programmes; and session feedback (intervention only). Outcome assessors will be blind to trial group allocation. Qualitative interviews with a subsample of facilitators and invention-arm participants will provide data on intervention feasibility and acceptability. Assessment of intervention fidelity will also be performed. DISCUSSION: The STEPWISE trial will provide evidence for the clinical and cost-effectiveness of a tailored intervention, which, if successful, could be implemented rapidly in the NHS. TRIAL REGISTRATION: ISRCTN19447796 , registered on 20 March 2014

Identification of additional risk loci for stroke and small vessel disease: a meta-analysis of genome-wide association studies

BACKGROUND: Genetic determinants of stroke, the leading neurological cause of death and disability, are poorly understood and have seldom been explored in the general population. Our aim was to identify additional loci for stroke by doing a meta-analysis of genome-wide association studies. METHODS: For the discovery sample, we did a genome-wide analysis of common genetic variants associated with incident stroke risk in 18 population-based cohorts comprising 84 961 participants, of whom 4348 had stroke. Stroke diagnosis was ascertained and validated by the study investigators. Mean age at stroke ranged from 45·8 years to 76·4 years, and data collection in the studies took place between 1948 and 2013. We did validation analyses for variants yielding a significant association (at p<5 × 10(-6)) with all-stroke, ischaemic stroke, cardioembolic ischaemic stroke, or non-cardioembolic ischaemic stroke in the largest available cross-sectional studies (70 804 participants, of whom 19 816 had stroke). Summary-level results of discovery and follow-up stages were combined using inverse-variance weighted fixed-effects meta-analysis, and in-silico lookups were done in stroke subtypes. For genome-wide significant findings (at p<5 × 10(-8)), we explored associations with additional cerebrovascular phenotypes and did functional experiments using conditional (inducible) deletion of the probable causal gene in mice. We also studied the expression of orthologs of this probable causal gene and its effects on cerebral vasculature in zebrafish mutants. FINDINGS: We replicated seven of eight known loci associated with risk for ischaemic stroke, and identified a novel locus at chromosome 6p25 (rs12204590, near FOXF2) associated with risk of all-stroke (odds ratio [OR] 1·08, 95% CI 1·05-1·12, p=1·48 × 10(-8); minor allele frequency 21%). The rs12204590 stroke risk allele was also associated with increased MRI-defined burden of white matter hyperintensity-a marker of cerebral small vessel disease-in stroke-free adults (n=21 079; p=0·0025). Consistently, young patients (aged 2-32 years) with segmental deletions of FOXF2 showed an extensive burden of white matter hyperintensity. Deletion of Foxf2 in adult mice resulted in cerebral infarction, reactive gliosis, and microhaemorrhage. The orthologs of FOXF2 in zebrafish (foxf2b and foxf2a) are expressed in brain pericytes and mutant foxf2b(-/-) cerebral vessels show decreased smooth muscle cell and pericyte coverage. INTERPRETATION: We identified common variants near FOXF2 that are associated with increased stroke susceptibility. Epidemiological and experimental data suggest that FOXF2 mediates this association, potentially via differentiation defects of cerebral vascular mural cells. Further expression studies in appropriate human tissues, and further functional experiments with long follow-up periods are needed to fully understand the underlying mechanisms