407 research outputs found

    Mechanism and dynamics of the CO-induced lifting of the Pt(100) surface reconstruction

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    The first atomistic simulations of the CO-induced lifting of the Pt(100)-hex reconstruction have been performed. During this phase transformation the surface changes back to bulk-terminated Pt(100)-(1×1), whereby the surface atom density decreases by ~20%. The simulations reveal a mechanism collective in nature, indicating that restructuring proceeds through ejection of chains of Pt atoms. These chains explain the anisotropy as seen in scanning tunneling microscopy experiments. The restructuring rate depends nonlinearly on the CO coverage, but the absence of local clustering of CO excludes an explanation in terms of elementary reaction kinetics as proposed previously

    Barriers and facilitators to physical activity among children, adolescents, and young adults with cystic fibrosis: A systematic review and thematic synthesis of qualitative of research

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    This is the final version. Available from BMJ Publishing Group via the DOI in this record.Availability of data and material: All data relevant to the study are included in the article or uploaded as supplementary information.Objectives: Physical activity is widely recommended in the treatment and management of cystic fibrosis (CF). Despite the numerous physical and psychological benefits, many young people with CF are not achieving the recommended levels of physical activity. The aim of this systematic review was to identify and synthesise available qualitative investigations exploring the motives for, barriers to and facilitators of physical activity among young people with CF. Methods: The following six electronic databases were systematically searched: ASSIA, CINAH, EMBASE, MEDLINE, MEDLINE-in-process, PsycINFO up to August 2019. Keywords were used to identify qualitative research that explored engagement in physical activity among young people with CF. Titles and abstracts were screened by two independent reviewers, and potentially relevant articles were retrieved in full. Articles were eligible for inclusion if they employed any qualitative method and recruited participants under the age of 24 years with CF. Risk of bias of included studies were assessed via the Critical Appraisal Skills Program. Results were synthesised using a thematic approach. Results: Seven studies met our inclusion criteria and were included in the review. Overall, studies were of moderate to high quality. Thematic synthesis identified nine main themes that encompass motives for, barriers to and facilitators of physical activity among young people with CF. These were 1) perceptions of physical activity, 2) value attributed to physical activity, 3) social influences, 4) competing priorities, 5) fluctuating health, 6) normality, 7) control beliefs, 8) coping strategies, and 9) availability of facilities. Previous reviews have been unable to identify intervention characteristics that influence physical activity behaviour. Conclusions: This review provides detailed information on the physical (biological – clinical), psychological, social, and environmental influences on physical activity behaviour, thus providing numerous targets for future interventions. This in turn could facilitate promotion of physical activity among young people with CF.Cystic Fibrosis TrustVertex Pharmaceutical

    Patient perceptions of the side-effects of chemotherapy: the influence of 5HT3 antagonists.

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    In 1983, Coates conducted a survey that ranked the side-effects perceived by patients receiving chemotherapy in the order of their severity. Vomiting and nausea were found to be the two most distressing side-effects. They have an impact on quality of life and compliance with treatment. The development of 5HT3 antagonists has been a major step forward in the prevention and treatment of chemotherapy-induced nausea and vomiting. Presently, these antiemetics are routinely used as concomitant therapy in emetogenic chemotherapy regimens. The purpose of this study was to evaluate the impact of 5HT3 antagonists on patient perceptions of the side-effects of chemotherapy. Coates' survey was replicated in patients who received 5HT3 antagonists for acute nausea and vomiting resulting from emetogenic chemotherapy. Patients received the survey to identify those physical and non-physical side-effects that they attributed to chemotherapy and were asked to rank the five most distressing side-effects. Of the 197 patients who consented to take part in the study, 181 were evaluable. Nausea, hair loss and vomiting were described as the three most distressing side-effects of chemotherapy. Eighty per cent of all the patients actually experienced nausea and 57% experienced vomiting. Hair loss appeared to be more distressing to women (P < 0.001) but, in other aspects, gender, age and marital status did not influence the ranking of the three most distressing side-effects. Constipation was ranked as 6th and was not identified as a distressing side-effect in 1983. Nausea and vomiting remain to be the first and third most distressing side-effects of chemotherapy, even though the incidence and severity of acute nausea and vomiting are now significantly reduced

    Functional interaction between the epidermal growth factor receptor and c-Src kinase activity

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    AbstractTo study the relationship between the tyrosine kinase c-Src and the epidermal growth factor receptor (EGF-R), we used the breast cancer cell line ZR75-1, which was transfected with the EGF-R. The EGF-R transfected cell line expressed 60 times more EGF-R than a control cell line transfected with the empty vector. In the presence of EGF, the EGF-R over-expressing cell line grew much faster than the control cell line. Both cell lines expressed approximately equal amounts of c-Src. However, the cell line over-expressing the EGF-R showed a twofold enhancement of c-Src kinase activity after EGF stimulation. The activation of c-Src kinase by EGF was confirmed in other EGF-R expressing cell types

    Augmenting muscle diacylglycerol and triacylglycerol content by blocking fatty acid oxidation does not impede insulin sensitivity

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    A low fat oxidative capacity has been linked to muscle diacylglycerol (DAG) accumulation and insulin resistance. Alternatively, a low fat oxidation rate may stimulate glucose oxidation, thereby enhancing glucose disposal. Here, we investigated whether an ethyl-2-[6-(4-chlorophenoxy)hexyl]-oxirane-2-carboxylate (etomoxir)-induced inhibition of fat oxidation leads to muscle fat storage and insulin resistance. An intervention in healthy male subjects was combined with studies in human primary myotubes. Furthermore, muscle DAG and triacylglycerol (TAG), mitochondrial function, and insulin signaling were examined in etomoxir-treated C57bl6 mice. In humans, etomoxir administration increased glucose oxidation at the expense of fat oxidation. This effect was accompanied by an increased abundance of GLUT4 at the sarcolemma and a lowering of plasma glucose levels, indicative of improved glucose homeostasis. In mice, etomoxir injections resulted in accumulation of muscle TAG and DAG, yet improved insulin-stimulated GLUT4 translocation. Also in human myotubes, insulin signaling was improved by etomoxir, in the presence of increased intramyocellular lipid accumulation. These insulin-sensitizing effects in mice and human myotubes were accompanied by increased phosphorylation of AMP-activated protein kinase (AMPK). Our results show that a reduction in fat oxidation leading to accumulation of muscle DAG does not necessarily lead to insulin resistance, as the reduction in fat oxidation may activate AMPK

    CO-induced lifting of Au (001) surface reconstruction

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    We report CO-induced lifting of the hexagonal surface reconstruction on Au (001). Using in-situ surface x-ray scattering, we determined a pressure-temperature phase diagram for the reconstruction and measured the dynamical evolution of the surface structure in real time. Our observations provide evidence that, under certain conditions, even macroscopic Au surfaces, much larger than catalytic Au nanoparticles [M. Haruta, Catal. Today 36, 153 (1997)], can exhibit some of the reactive properties and surface transitions observed in systems known to be catalytically active such as Pt (001).Comment: 4 Figures. Accepted as a Letter to Journal of Physical Chemistry

    Correction: Getting evidence into clinical practice: protocol for evaluation of the implementation of a home-based cardiac rehabilitation programme for patients with heart failure.

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    This is the final version. Available on open access from BMJ Publishing group via the DOI in this recordThe article to which this is the correction is available in ORE at http://hdl.handle.net/10871/121757This is a correction to: Daw P, van Beurden SB, Greaves C, et al. Getting evidence into clinical practice: protocol for evaluation of the implementation of a home- based cardiac rehabilitation programme for patients with heart failure. BMJ Open 2020;10:e036137. doi: 10.1136/ bmjopen-2019-036137. This article was previously published with an error. The paper was linked to an incorrect trial registration number, which has now been remove
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