1,095 research outputs found

    Influence of MWCNT/surfactant dispersions on the mechanical properties of Portland cement pastes

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    This work studies the reinforcing effect of Multi Walled Carbon Nanotubes (MWCNT) on cement pastes. A 0.35% solid concentration of MWCNT in powder was dispersed in deionized water with sodium dodecyl sulfate (cationic surfactant), cetylpyridinium chloride (anionic surfactant) and triton X-100 (amphoteric surfactant) using an ultrasonic tip processor. Three concentrations of each surfactant (1mM, 10mM and 100mM) were tested, and all samples were sonicated until an adequate dispersion degree was obtained. Cement pastes with additions of carbon nanotubes of 0.15% by mass of cement were produced in two steps; first the dispersions of MWCNT were combined with the mixing water using an ultrasonic tip processor to guarantee homogeneity, and then cement was added and mixed until a homogeneous paste was obtained. Direct tensile strength, apparent density and open porosity of the pastes were measured after 7 days of curing. It was found that the MWCNT/surfactants dispersions decrease the mechanical properties of the cement based matrix due to an increased porosity caused by the presence of surfactants. © Published under licence by IOP Publishing Ltd

    The unconstrained evolution of fast and efficient antibiotic-resistant bacterial genomes

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    PublishedThis is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.-The rrn knockout strains derived from E. coli MG1655 were gifted by T. Bollenbach, strain AG100 was provided by S. Levy and Candida strains were a gift from S. Bates, who are sincerely thanked for their help

    Mechanism of association of adenylate cyclase toxin with the surface of Bordetella pertussis : a role for toxin-filamentous haemagglutinin interaction

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    Summary Adenylate cyclase (AC) toxin from Bordetella pertussis is unusual in that, unlike most other members of the repeats-in-toxin family that are released into the extracellular milieu, it remains associated with the bacterial surface. In this study, we investigated the nature of the association of this toxin with the surface of B. pertussis . AC toxin was extracted from crude outer membrane preparations of B. pertussis with 8 M urea, but only partially with alkaline sodium carbonate and not at all with octylglucoside, suggesting that denaturation of the toxin is necessary for its removal from the membrane. B. pertussis mutants lacking filamentous haemagglutinin (FHA) released significantly more AC toxin into the medium, and AC toxin association with the bacterial surface was partially restored by expression of FHA from a plasmid, suggesting a role for FHA in surface retention of AC toxin. AC toxin distribution was unaffected by the absence of pertactin, or full-length lipopolysaccharide, or a defect in secretion of pertussis toxin. Using overlay and immunoprecipitation, we found that a direct physical association can occur between AC toxin and FHA. Combined, these findings suggest that FHA may play a role in AC toxin retention on the surface of B. pertussis and raise the possibility of an involvement of adherence mediated by FHA in delivery of AC toxin from the bacterium to the target cell

    The Mental Wellbeing of Child and Adolescent Mental Health Service (CAMHS) Workers in England: A Cross-Sectional Descriptive Study Reporting Levels of Burnout, Wellbeing and Job Satisfaction

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    In the UK, there has been a notable increase in referrals to specialist children’s mental health services. This, coupled with shortages of qualified staff, has raised concerns about the escalating occupational stress experienced by staff in this sector. In this brief report, we present cross-sectional quantitative data from 97 staff members working in one Child and Adolescent Mental Health Service (CAMHS) in the UK during spring 2023, reporting on their wellbeing, job satisfaction, and burnout. Our findings reveal that over a third of CAMHS staff experienced moderate or high levels of work-related burnout; 39% reported moderate or high levels of personal burnout, but levels of client-related burnout were much lower (13%). Both work- and client-related burnout showed a robust negative relationship with job satisfaction, with higher burnout predicting lower levels of job satisfaction. Only a small proportion of respondents reported high levels of wellbeing, with about a quarter experiencing levels of wellbeing that can be considered indicative of mild or clinical depressive symptoms. Whilst these results are from a small sample in one area of the UK, they present an important snapshot of CAMHS staff wellbeing and are discussed in the context of similar trends reported in the wider NHS sector

    Beyond the SCS-CN method : A theoretical framework for spatially lumped rainfall-runoff response

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    Acknowledgments This work was supported through the USDA Agricultural Research Service cooperative agreement 58-6408-3-027; and National Science Foundation (NSF) grants CBET-1033467, EAR-1331846, FESD-1338694, EAR-1316258, and the Duke WISeNet grant DGE-1068871. The data used for Figure 9 are reproduced from Tedela et al. [2011, 2008]. Processed data and code are available by e-mail from the corresponding author. We thank the reviewers for their useful and constructive comments that helped improve the paper.Peer reviewedPublisher PD

    Why is it so hard to enact responsible change?: Scientists need to work more closely with other social groups to implement sustainable innovation

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    This is the final version. Available on open access from EMBO Press via the DOI in this record. Biotechnology and Biological Sciences Research Council (BBSRC)UK Research and Innovation | Engineering and Physical Sciences Research Council (EPSRC)Wellcome Trus

    Long-Term Assessment of the Effects of COVID-19 and Isolation Care on Survivor Disability and Anxiety

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    We conducted an assessment of disability, anxiety, and other life impacts of COVID-19 and isolation care in a unique cohort of individuals. These included both community admissions to a university hospital as well as some of the earliest international aeromedical evacuees. Among an initial 16 COVID-19 survivors that were interviewed 6-12 months following their admission into isolation care, perception of their isolation care experience was related to their reporting of long-term consequences. However, anxiety and disability assessed with standard scores had no relationship with each other. Both capture of the isolation care experience and caution relying on single scoring systems for assessing long-term consequences in survivors are important considerations for on-going and future COVID-19 and other pandemic survivor research

    A Q-methodology study of flare help-seeking behaviours and different experiences of daily life in rheumatoid arthritis

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    © 2014 Lin et al.; licensee BioMed Central Ltd. Background: Previous studies have not addressed rheumatoid arthritis (RA) patients' help-seeking behaviours for RA flares, and only one small qualitative study has addressed how patients experience daily life on current treatment regimes. Thus, this study aims to identify clusters of opinion related to RA patients' experiences of daily life on current treatments, and their help-seeking behaviours for RA flares. Methods: Using Q-methodology (a methodology using qualitative and quantitative methods to sort people according to subjective experience), two separate studies were conducted with the same sample of RA patients (mean age 55, 73% female). Thirty participants sorted 39 statements about daily life (Q-study 1) and 29 participants separately sorted 23 statements about flare help-seeking (Q-study 2). Data were examined using Q-factor analysis. Results: Daily life with RA (Q-study 1): Three factors relating to the experience of living with RA were extracted and explained. Patients belonging to Factor A (mean age 62, 86% female) use effective self-management techniques to control the daily impact of RA. Those in Factor B (mean age 55, 75% male) struggle to self-manage and cope. Whilst patients in Factor C (mean age 42, 100% female) prioritise life responsibilities over their RA, reporting less impact. Flare help-seeking (Q-study 2): Two factors explaining the experience of flare help-seeking (unrelated to the factors from Q-study 1) were extracted and explained. Factor X (68.8% on biologics) reported seeking help quickly, believing the medical team is there to help. Factor Y (0% on biologics) delay help-seeking, concerned about wasting the rheumatologist's time, believing they should manage alone. All participants agreed they sought help due to intense pain and persistent, unmanageable symptoms. Conclusions: Patients with different characteristics appear to manage RA life in different ways and men may struggle more than women. Whilst all patients are prompted to seek help by persistent, unmanageable symptoms, some delay help-seeking. Further research is needed to quantify the severity of daily symptoms, the level of symptoms needed for patients to define themselves as in flare and to understand the support needs of RA men

    Group cognitive–behavioural programme to reduce the impact of rheumatoid arthritis fatigue: The RAFT RCT with economic and qualitative evaluations

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    BACKGROUND: Fatigue is a major problem in rheumatoid arthritis (RA). There is evidence for the clinical effectiveness of cognitive-behavioural therapy (CBT) delivered by clinical psychologists, but few rheumatology units have psychologists. OBJECTIVES: To compare the clinical effectiveness and cost-effectiveness of a group CBT programme for RA fatigue [named RAFT, i.e. Reducing Arthritis Fatigue by clinical Teams using cognitive-behavioural (CB) approaches], delivered by the rheumatology team in addition to usual care (intervention), with usual care alone (control); and to evaluate tutors' experiences of the RAFT programme. DESIGN: A randomised controlled trial. Central trials unit computerised randomisation in four consecutive cohorts within each of the seven centres. A nested qualitative evaluation was undertaken. SETTING: Seven hospital rheumatology units in England and Wales. PARTICIPANTS: Adults with RA and fatigue severity of ≥ 6 [out of 10, as measured by the Bristol Rheumatoid Arthritis Fatigue Numerical Rating Scale (BRAF-NRS)] who had no recent changes in major RA medication/glucocorticoids. INTERVENTIONS: RAFT - group CBT programme delivered by rheumatology tutor pairs (nurses/occupational therapists). Usual care - brief discussion of a RA fatigue self-management booklet with the research nurse. MAIN OUTCOME MEASURES: Primary - fatigue impact (as measured by the BRAF-NRS) at 26 weeks. Secondary - fatigue severity/coping (as measured by the BRAF-NRS); broader fatigue impact [as measured by the Bristol Rheumatoid Arthritis Fatigue Multidimensional Questionnaire (BRAF-MDQ)]; self-reported clinical status; quality of life; mood; self-efficacy; and satisfaction. All data were collected at weeks 0, 6, 26, 52, 78 and 104. In addition, fatigue data were collected at weeks 10 and 18. The intention-to-treat analysis conducted was blind to treatment allocation, and adjusted for baseline scores and centre. Cost-effectiveness was explored through the intervention and RA-related health and social care costs, allowing the calculation of quality-adjusted life-years (QALYs) with the EuroQol-5 Dimensions, five-level version (EQ-5D-5L). Tutor and focus group interviews were analysed using inductive thematic analysis. RESULTS: A total of 308 out of 333 patients completed 26 weeks (RAFT, n/N = 156/175; control, n/N = 152/158). At 26 weeks, the mean BRAF-NRS impact was reduced for the RAFT programme (-1.36 units; p
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