103 research outputs found

    Microfluidic systems for the analysis of the viscoelastic fluid flow phenomena in porous media

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    In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/ expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application

    A ‘quiet revolution’? The impact of Training Schools on initial teacher training partnerships

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    This paper discusses the impact on initial teacher training of a new policy initiative in England: the introduction of Training Schools. First, the Training School project is set in context by exploring the evolution of a partnership approach to initial teacher training in England. Ways in which Training Schools represent a break with established practice are considered together with their implications for the dominant mode of partnership led by higher education institutions (HEIs). The capacity of Training Schools to achieve their own policy objectives is examined, especially their efficacy as a strategy for managing innovation and the dissemination of innovation. The paper ends by focusing on a particular Training School project which has adopted an unusual approach to its work and enquires whether this alternative approach could offer a more profitable way forward. During the course of the paper, five different models of partnership are considered: collaborative, complementary, HEI-led, school-led and partnership within a partnership

    A perspective on the measurement of time in plant disease epidemiology

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    The growth and development of plant pathogens and their hosts generally respond strongly to the temperature of their environment. However, most studies of plant pathology record pathogen/host measurements against physical time (e.g. hours or days) rather than thermal time (e.g. degree-days or degree-hours). This confounds the comparison of epidemiological measurements across experiments and limits the value of the scientific literature

    HealtheSteps™ Study Protocol: a pragmatic randomized controlled trial promoting active living and healthy lifestyles in at-risk Canadian adults delivered in primary care and community-based clinics

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    Abstract Background Physical inactivity is one of the leading causes of chronic disease in Canadian adults. With less than 50% of Canadian adults reaching the recommended amount of daily physical activity, there is an urgent need for effective programs targeting this risk factor. HealtheSteps™ is a healthy lifestyle prescription program, developed from an extensive research base to address risk factors for chronic disease such as physical inactivity, sedentary behaviour and poor eating habits. HealtheSteps™ participants are provided with in-person lifestyle coaching and access to eHealth technologies delivered in community-based primary care clinics and health care organizations. Method/Design To determine the effectiveness of Healthesteps™, we will conduct a 6-month pragmatic randomized controlled trial with integrated process and economic evaluations of HealtheSteps™ in 5 clinic settings in Southwestern Ontario. 110 participants will be individually randomized (1:1; stratified by site) to either the intervention (HealtheSteps™ program) or comparator (Wait-list control). There are 3 phases of the HealtheSteps™ program, lasting 6 months each. The active phase consists of bi-monthly in-person coaching with access to a full suite of eHealth technology supports. During the maintenance phase I, the in-person coaching will be removed, but participants will still have access to the full suite of eHealth technology supports. In the final stage, maintenance phase II, access to the full suite of eHealth technology supports is removed and participants only have access to publicly available resources and tools. Discussion This trial aims to determine the effectiveness of the program in increasing physical activity levels and improving other health behaviours and indicators, the acceptability of the HealtheSteps™ program, and the direct cost for each person participating in the program as well as the costs associated with delivering the program at the different community sites. These results will inform future optimization and scaling up of the program into additional community-based primary care sites. Trial registration NCT02413385 (Clinicaltrials.gov). Date Registered: April 6, 2015

    Improving patient experience and safety at transitions of care through the Your Care Needs You (YCNY) intervention: a study protocol for a cluster randomised controlled feasibility trial

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    Background Patients, particularly older people, often experience safety issues when transitioning from hospital to home. Although the evidence is currently equivocal as to how we can improve this transition of care, interventions that support patient involvement may be more effective. The ‘Your Care Needs You’ (YCNY) intervention supports patients to ‘know more’ and ‘do more’ whilst in hospital in order that they better understand their health condition and medications, maintain their daily activities, and can seek help at home if required. The intervention aims to reduce emergency hospital readmissions and improve safety and experience during the transition to home. Methods As part of the Partners At Care Transitions (PACT) programme of research, a multi-centred cluster randomised controlled trial (cRCT) will be conducted to explore the feasibility of the YCNY intervention and trial methodology. Data will be used to refine the intervention and develop a protocol for a definitive cRCT. Ten acute hospital wards (the clusters) from varying medical specialties including older peoples’ medicine, trauma and orthopaedics, cardiology, intermediate care, and stroke will be randomised to deliver YCNY or usual care on a 3:2 basis. Up to 200 patients aged 75 years and over and discharged to their own homes will be recruited to the study. Patients will complete follow-up questionnaires at 5-, 30-, and 90-days post-discharge and readmission data up to 90-days post-discharge will be extracted from their medical records. Study outcomes will include measures of feasibility (e.g. screening, recruitment, and retention data) and processes required to collect routine data at a patient and ward level. In addition, interviews and observations involving up to 24 patients/carers and 28 staff will be conducted to qualitatively assess the acceptability, usefulness, and feasibility of the intervention and implementation package to patients and staff. A separate sub-study will be conducted to explore how accurately primary outcome data (30-day emergency hospital readmissions) can be gathered for the definitive cRCT. Discussion This study will establish the feasibility of the YCNY intervention which aims to improve safety and experience during transitions of care. It will identify key methodological and implementation issues that need to be addressed prior to assessing the effectiveness of the YCNY intervention in a definitive cluster randomised controlled trial. Trial registration UK Clinical Research Network Portfolio: 42191; ISTCRN: ISRCTN51154948. Registered 16/07/2019

    Secondary Metabolites of Marine Microbes: From Natural Products Chemistry to Chemical Ecology

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    Marine natural products (MNPs) exhibit a wide range of pharmaceutically relevant bioactivities, including antibiotic, antiviral, anticancer, or anti-inflammatory properties. Besides marine macroorganisms such as sponges, algae, or corals, specifically marine bacteria and fungi have shown to produce novel secondary metabolites (SMs) with unique and diverse chemical structures that may hold the key for the development of novel drugs or drug leads. Apart from highlighting their potential benefit to humankind, this review is focusing on the manifold functions of SMs in the marine ecosystem. For example, potent MNPs have the ability to exile predators and competing organisms, act as attractants for mating purposes, or serve as dye for the expulsion or attraction of other organisms. A large compilation of literature on the role of MNPs in marine ecology is available, and several reviews evaluated the function of MNPs for the aforementioned topics. Therefore, we focused the second part of this review on the importance of bioactive compounds from crustose coralline algae (CCA) and their role during coral settlement, a topic that has received less attention. It has been shown that certain SMs derived from CCA and their associated bacteria are able to induce attachment and/or metamorphosis of many benthic invertebrate larvae, including globally threatened reef-building scleractinian corals. This review provides an overview on bioactivities of MNPs from marine microbes and their potential use in medicine as well as on the latest findings of the chemical ecology and settlement process of scleractinian corals and other invertebrate larvae

    Costs of cancer care for use in economic evaluation: a UK analysis of patient-level routine health system data.

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    BACKGROUND: The rising financial burden of cancer on health-care systems worldwide has led to the increased demand for evidence-based research on which to base reimbursement decisions. Economic evaluations are an integral component of this necessary research. Ascertainment of reliable health-care cost and quality-of-life estimates to inform such studies has historically been challenging, but recent advances in informatics in the United Kingdom provide new opportunities. METHODS: The costs of hospital care for breast, colorectal and prostate cancer disease-free survivors were calculated over 15 months from initial diagnosis of cancer using routinely collected data within a UK National Health Service (NHS) Hospital Trust. Costs were linked at patient level to patient-reported outcomes and registry-derived sociodemographic factors. Predictors of cost and the relationship between costs and patient-reported utility were examined. RESULTS: The study population included 223 breast cancer patients, 145 colorectal and 104 prostate cancer patients. The mean 15-month cumulative health-care costs were £12 595 (95% CI £11 517-£13 722), £12 643 (£11 282-£14 102) and £3722 (£3263-£4208), per-patient respectively. The majority of costs occurred within the first 6 months from diagnosis. Clinical stage was the most important predictor of costs for all cancer types. EQ-5D score was predictive of costs in colorectal cancer but not in breast or prostate cancer. CONCLUSION: It is now possible to evaluate health-care cost using routine NHS data sets. Such methods can be utilised in future retrospective and prospective studies to efficiently collect economic data
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