67 research outputs found

    Doping Effects on the Performance of Paired Metal Catalysts for the Hydrogen Evolution Reaction

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    Metal heteroatoms dispersed in nitrogen-doped graphene display promising catalytic activity for fuel cell reactions such as the hydrogen evolution reaction (HER). Here we explore the effects of dopant concentration on the synergistic catalytic behaviour of a paired metal atom active site comprised of Co and Pt atoms. The metals are coordinated to six atoms in a vacancy of N-doped graphene. We find that HER activity is enhanced with increasing N concentration, where the free energy of hydrogen atom adsorption ranges from 0.23 to -0.42 eV as the doping changes from a single N atom doped in the pore, to fully doped coordination sites. The results indicated that the effect of N is to make the Co atom more active towards H adsorption and presents a means through which transition metals can be modified to make more effective and sustainable fuel cell catalysts

    1,2,3,4-Tetra­methyl­cyclo­pent-2-ene-1,4-diol

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    The title compound, C9H16O2, crystallizes with two mol­ecules in the asymmetric unit. The structure displays inter­molecular O—H⋯O hydrogen bonding

    Evaluating the catalytic efficiency of paired, single-atom catalysts for the oxygen reduction reaction

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    Paired, single-atom catalysts have been shown to demonstrate synergistic effects computationally and experimentally which enable them to outperform the benchmark catalyst, Pt/C, for electrochemical reactions. We explore the limit of these catalysts by screening different transition metal atoms (M = Co, Pt, Fe, Ni) in nitrogen-doped graphene for their ability to catalyze the oxygen reduction reaction (ORR). We employ density functional theory methods to explore the electronic factors affecting catalytic activity in an effort to rationalize trends in the performance of materials which are promising candidates for the next generation of electrocatalysts. It is found that CoPt@N8V4, composed of paired Co and Pt in a nitrogen-doped four-atom vacancy in graphene (N8V4), performs ideally for the ORR with an overpotential (η) of 0.30 V, followed closely by Co and Ni (η = 0.35 V) and paired Co (η = 0.37 V). The origin of activity is suggested to be the changing reduction potential of the active Co atom via the local distortion of the pore by the spectating metal partner. We utilize the ORR scaling relations and plot catalytic activity on a volcano plot, which we correlate with the degree of antibonding interactions with the O atom in the OH intermediate of the ORR. We establish that the local tuning of paired catalysts allows for the reactivity of metal atoms to be specifically modified for desirable reactivity

    A feasibility study on two tailored interventions to improve adherence in adults with haemophilia

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    Introduction: Haemophilia is a congenital bleeding disorder mainly affecting males. To prevent bleeding, patients need to perform regular intravenous injections (prophylaxis) throughout life. Non-adherence often occurs. Problems with acceptance or self-management appear to be the main reasons for non-adherence in haemophilia. The aim of this study was to test the feasibility and effects of two interventions focussed on acceptance (face-to-face) and self-management (online). Methods: Patients with severe haemophilia and acceptance or self-management problems were eligible. The face-to-face group intervention was based on Acceptance and Commitment Therapy (ACT) (8 sessions/6 months, target N = 8 participants). The online intervention was based on a successful online programme in rheumatoid arthritis (5–8 modules/2 months, target N = 8). Both interventions were designed according to the MRC framework in collaboration with the patient society and experts. We compared adherence (VERITAS-Pro, optimum 0), quality of life (SF-36, optimum 100) and illness perception (BIPQ, optimum 0) before start (T0) and after 2 months (T2). Feasibility criteria were as follows: completion of training by > 50% of participants and ability to collect at least 80% of outcome parameters. Results: The face-to-face intervention was feasible (89% enrolment and recruitment, 100% retention). One hundred percent of the outcome parameters was collected. Results were promising: although adherence (VERITAS-Pro) was stable (from 64 to 62 points), quality of life (SF-36) showed a clinically relevant improvement (> 5 points) in five of eight domains. Illness perception (BIPQ) showed a clinically relevant increase from 47 to 39 points. Patient evaluation was positive. The online intervention, however, was infeasible: enrolment was only 20% (6/30). Only three patients signed informed consent (recruitment 10%), and none completed more than one module (retention 0%). Consequently, the online intervention was terminated. Conclusion: The face-to-face acceptance intervention was considered feasible with promising results. Unfortunately, the online intervention was infeasible and therefore terminated. These findings suggest that adapting effective interventions to other settings does not guarantee success, despite the use of established methodology and patient participation. Population differences (only male participants, congenital disease) could be an explanation for failure of the online intervention in haemophilia despite success in rheumatoid arthritis. Trial registration: NL55883.041.16

    The experiences and attitudes of hemophilia carriers around pregnancy: A qualitative systematic review

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    Background: Hemophilia carriers (HCs) face specific psychosocial challenges related to pregnancy, caused by their inherited bleeding disorder. Optimal support from healthcare providers can only be realized by exploring medical and psychological healthcare requirements. Objective: To review all published evidence on the experiences and attitudes of HCs regarding reproductive decision-making, prenatal diagnosis, pregnancy, childbirth, and puerperium to provide an accessible overview of this information for health care providers. Study selection: Cochrane library, PubMed/MEDLINE, EMBASE, CINAHL, and PsycINFO were searched for original qualitative data. Two authors performed study selection, risk-of-bias assessment, data extraction, and data analysis through meta-summary. The extracted themes were discussed within the research team. Findings: Fifteen studies with an overall moderate quality were included. The following findings were identified: (a) Quality of life of family members with hemophilia influences reproductive decision-making; (b) Genetic counselling is generally considered useful; (c) The development of a specialized carrier clinic is considered valuable; (d) HCs describe prenatal diagnosis as beneficial yet psychosocially challenging; and (e) noninvasive prenatal diagnosis and preimplantation genetic diagnosis are predominantly considered beneficial. These findings are limited by the overall moderate quality of included studies and the possibly partly outdated results in the current era of hemophilia treatment. Conclusions: Available qualitative literature on HCs around pregnancy focuses on genetic counselling and prenatal diagnosis. Future studies are needed on the experiences and needs of HCs through pregnancy and puerperium as well as in light of emerging hemophilia diagnosis and treatment options

    Prevalence and influence on outcome of HER2/neu, HER3 and NRG1 expression in patients with metastatic colorectal cancer

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    Our aim was to explore the impact of the HER2/neu, HER3 receptor as well as their ligands' neuregulin (NRG1) expression on the outcome of patients with metastatic colorectal cancer (mCRC). NRG1, HER2/neu and HER3 expression was evaluated in 208 patients with mCRC receiving 5-FU/LV plus irinotecan or irinotecan plus oxaliplatin as the first-line treatment. Biomarker expression was correlated with the outcome of patients. NRG1 (low: 192 vs. high: 16), HER2/neu (low: 201 vs. high: 7) and HER3 (low: 69 vs. high: 139) expressions were assessed in 208 patients. High versus low NRG1 expression significantly affected progression-free survival (PFS) 4.7 vs. 8.2 months, hazard ratio (HR): 2.45; 95{\%} confidence interval (CI): 1.45-4.13; P=0.001, but not overall survival (OS) (15.5 vs. 20.7 months, HR: 1.33; 95{\%} CI: 0.76-2.35; P=0.32). High versus low HER3 expression (PFS: 7.1 vs. 8.8 months, HR: 1.11; 95{\%} CI: 0.82-1.50; P=0.50; OS: 19.8 vs. 21.1 months, HR: 0.95; 95{\%} CI: 0.70-1.30; P=0.75) and high compared with low HER2/neu expression (PFS: 7.7 vs. 8.0 months, HR: 1.07; 95{\%} CI: 0.71-1.60; P=0.75; OS: 16.6 vs. 21.1 months, HR: 1.13; 95{\%} CI: 0.75-1.71; P=0.57) did not influence outcome. High NRG1 expression was associated with inferior PFS in the FIRE-1 trial. We did not detect a prognostic impact of HER2/neu and HER3 overexpression in mCRC. The frequency of overexpression was comparable with other studies

    Enhanced CO2 photocatalytic reduction on alkali-decorated graphitic carbon nitride

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    In this work, visible-light photocatalytic reduction performance of carbon dioxide (CO) on graphitic carbon nitride (g-CN) was significantly promoted by the decoration of potassium hydroxide (KOH) on g-CN. More importantly, the role of KOH was thoroughly discussed via various characterizations, control experiments and density functional theory (DFT) calculations. It was found that KOH decoration did not result in any significant difference regards to the morphology, elemental states, BET surface area and light adsorption of g-CN except a drastically enhanced CO adsorption capacity. The promotion effect of KOH on g-CN was mainly contributed by the hydroxide ion (OH) functioning as both a hole accepter and a driving force to keep a dynamically stable amount of HCO (probably the major form of CO to be reduced) on the surface of the catalyst. Moreover, the different extents of influence of NaOH and KOH on g-CN were revealed and further explained using computational results. This study supplements current understanding on alkali-promoted photocatalytic processes and provides new insights into the mechanism of CO photocatalytic reduction

    Progressive fibrosing interstitial lung diseases: current practice in diagnosis and management

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    Objective: Some patients with interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF) develop a progressive fibrosing phenotype. We investigated the diagnosis and management of non-IPF ILDs using data from a survey of physicians and from US insurance claims. Methods: Pulmonologists, rheumatologists and internists in France, Germany, Italy, Japan, Spain, UK and US who had managed ≥10 patients with non-IPF ILDs in the past year, including those with progressive fibrosing ILDs, completed an online survey. Data on US insurance and prescription claims were obtained from a repository that aggregates data on claims routed from providers or pharmacies to payers. Results: In May–June 2017, 243 pulmonologists, 203 rheumatologists and 40 internists completed an online survey. Respondents estimated that 18–32% of patients diagnosed with non-IPF ILDs develop progressive fibrosis and that time from symptom onset to death in these patients was 61–80 months. Drug treatment was given to 50–75% of patients with non-IPF progressive fibrosing ILDs. Reasons for patients not being treated included that physicians considered patients to have mild or slowly progressing disease, or did not believe that available treatments are effective or well tolerated. Corticosteroids were the preferred first-line treatment for all types of non-IPF ILD. There was considerable heterogeneity in preferences for second- and third-line treatments. US insurance claims data from 3823 patients indicated that, in 2016, 50–75% of patients with ILDs received drug treatment (mostly corticosteroids) for their ILD. Conclusions: Physicians estimate that 18–32% of patients diagnosed with non-IPF ILDs develop a progressive fibrosing phenotype and that these patients experience significant delays in the diagnosis of ILD and the detection of progressive fibrosis. Between 25% and 50% of patients with progressive fibrosing ILDs do not receive drug therapy. There is an unmet need for effective and well tolerated treatments for progressive fibrosing ILDs

    Situational awareness within objective structured clinical examination stations in undergraduate medical training - a literature search

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    Background: Medical students may not be able to identify the essential elements of situational awareness (SA) necessary for clinical reasoning. Recent studies suggest that students have little insight into cognitive processing and SA in clinical scenarios. Objective Structured Clinical Examinations (OSCEs) could be used to assess certain elements of situational awareness. The purpose of this paper is to review the literature with a view to identifying whether levels of SA based on Endsley's model can be assessed utilising OSCEs during undergraduate medical training. Methods: A systematic search was performed pertaining to SA and OSCEs, to identify studies published between January 1975 (first paper describing an OSCE) and February 2017, in peer reviewed international journals published in English. PUBMED, EMBASE, PsycINFO Ovid and SCOPUS were searched for papers that described the assessment of SA using OSCEs among undergraduate medical students. Key search terms included "objective structured clinical examination", "objective structured clinical assessment" or "OSCE" and "non-technical skills", "sense-making", "clinical reasoning", "perception", "comprehension", "projection", "situation awareness", "situational awareness" and "situation assessment". Boolean operators (AND, OR) were used as conjunctions to narrow the search strategy, resulting in the limitation of papers relevant to the research interest. Areas of interest were elements of SA that can be assessed by these examinations. Results: The initial search of the literature retrieved 1127 publications. Upon removal of duplicates and papers relating to nursing, paramedical disciplines, pharmacy and veterinary education by title, abstract or full text, 11 articles were eligible for inclusion as related to the assessment of elements of SA in undergraduate medical students. Discussion: Review of the literature suggests that whole-task OSCEs enable the evaluation of SA associated with clinical reasoning skills. If they address the levels of SA, these OSCEs can provide supportive feedback and strengthen educational measures associated with higher diagnostic accuracy and reasoning abilities. Conclusion: Based on the findings, the early exposure of medical students to SA is recommended, utilising OSCEs to evaluate and facilitate SA in dynamic environment

    Impacts of 1.5°C Global Warming on Natural and Human Systems

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    An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate povert
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