249 research outputs found

    Dispersion enhancement and damping by buoyancy driven flows in 2D networks of capillaries

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    The influence of a small relative density difference on the displacement of two miscible liquids is studied experimentally in transparent 2D networks of micro channels. Both stable displacements in which the denser fluid enters at the bottom of the cell and displaces the lighter one and unstable displacements in which the lighter fluid is injected at the bottom and displaces the denser one are realized. Except at the lowest mean flow velocity U, the average C(x,t)C(x,t) of the relative concentration satisfies a convection-dispersion equation. The dispersion coefficient is studied as function of the relative magnitude of fluid velocity and of the velocity of buoyancy driven fluid motion. A model is suggested and its applicability to previous results obtained in 3D media is discussed

    the COMIT’ID study protocol for using a Delphi process and face-to-face meetings to establish consensus

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    Background The reporting of outcomes in clinical trials of subjective tinnitus indicates that many different tinnitus-related complaints are of interest to investigators, from perceptual attributes of the sound (e.g. loudness) to psychosocial impacts (e.g. quality of life). Even when considering one type of intervention strategy for subjective tinnitus, there is no agreement about what is critically important for deciding whether a treatment is effective. The main purpose of this observational study is, therefore to, develop Core Outcome Domain Sets for the three different intervention strategies (sound, psychological, and pharmacological) for adults with chronic subjective tinnitus that should be measured and reported in every clinical trial of these interventions. Secondary objectives are to identify the strengths and limitations of our study design for recruiting and reducing attrition of participants, and to explore uptake of the core outcomes. Methods The ‘Core Outcome Measures in Tinnitus: International Delphi’ (COMIT’ID) study will use a mixed-methods approach that incorporates input from health care users at the pre-Delphi stage, a modified three-round Delphi survey and final consensus meetings (one for each intervention). The meetings will generate recommendations by stakeholder representatives on agreed Core Outcome Domain Sets specific to each intervention. A subsequent step will establish a common cross-cutting Core Outcome Domain Set by identifying the common outcome domains included in all three intervention-specific Core Outcome Domain Sets. To address the secondary objectives, we will gather feedback from participants about their experience of taking part in the Delphi process. We aspire to conduct an observational cohort study to evaluate uptake of the core outcomes in published studies at 7 years following Core Outcome Set publication. Discussion The COMIT’ID study aims to develop a Core Outcome Domain Set that is agreed as critically important for deciding whether a treatment for subjective tinnitus is effective. Such a recommendation would help to standardise future clinical trials worldwide and so we will determine if participation increases use of the Core Outcome Set in the long term. Trial registration This project has been registered (November 2014) in the database of the Core Outcome Measures in Effectiveness Trials (COMET) initiative

    Is Mercury Orange a selective stain for thiols?

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42852/1/10735_2005_Article_BF01005240.pd

    Assessing the bioactivity of crystalline silica in heated high-temperature insulation wools

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    High-Temperature Insulation Wools (HTIW), such as alumino silicate wools (Refractory Ceramic Fibers) and Alkaline Earth Silicate wools, are used in high-temperature industries for thermal insulation. These materials have an amorphous glass-like structure. In some applications, exposure to high temperatures causes devitrification resulting in the formation of crystalline species including crystalline silica. The formation of this potentially carcinogenic material raises safety concerns regarding after-use handling and disposal. This study aims to determine whether cristobalite formed in HTIW is bioactive in vitro. Mouse macrophage (J774A.1) and human alveolar epithelial (A549) cell lines were exposed to pristine HTIW of different compositions, and corresponding heat-treated samples. Cell death, cytokine release, and reactive oxygen species (ROS) formation were assessed in both cell types. Cell responses to aluminum lactate-coated fibers were assessed to determine if responses were caused by crystalline silica. DQ12 α-quartz was used as positive control, and TiO2 as negative control. HTIW did not induce cell death or intracellular ROS, and their ability to induce pro-inflammatory mediator release was low. In contrast, DQ12 induced cytotoxicity, a strong pro-inflammatory response and ROS generation. The modest pro-inflammatory mediator responses of HTIW did not always coincide with the formation of cristobalite in heated fibers; therefore, we cannot confirm that devitrification of HTIW results in bioactive cristobalite in vitro. In conclusion, the biological responses to HTIW observed were not attributable to a single physicochemical characteristic; instead, a combination of physicochemical characteristics (cristobalite content, fiber chemistry, dimensions and material solubility) appear to contribute to induction of cellular responses

    Patient and Public Involvement and Engagement for PhD Students

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    This paper aims to provide useful advice regarding the development of skills for patient and public involvement and engagement (PPIE) in research. The authors of this paper comprise experienced PhD supervisors and trainers, researchers leading PPIE activities including in the National Institute for Health and Social Care Research (NIHR) Nottingham Biomedical Research Centre (BRC), and experts in the conduct of PPIE. The paper arose from discussions in preparation for a programme of PPIE training for PhD students in the University of Nottingham, UK. We offer this advice on the basis that it is likely to be of use to others undertaking research training such as undergraduates or research associates moving into health-related research areas. Although the PPIE team of the NIHR Nottingham Biomedical Research Centre prepared this paper, we hope that it is of value across the whole spectrum of health research, not solely to experimental medicine and is of relevance to research more widely than that supported by the UK’s NIHR. The first section introduces PPIE, explains what it is and what it is not, and why it is important. The second section provides specific advice

    Redesigning a Web-Based Stakeholder Consensus Meeting About Core Outcomes for Clinical Trials: Formative Feedback Study

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    Background: Clinical trials that assess the benefits and harms of an intervention do so by measuring and reporting outcomes. Inconsistent selection and diversity in the choice of outcomes makes it challenging to directly compare interventions. To achieve an agreed core set of outcomes, a consensus methodology is recommended comprising a web-based Delphi survey and a face-to-face consensus meeting. However, UK-government regulations to control the pandemic prohibited plans for a face-to-face consensus meeting as part of the Core Rehabilitation Outcome Set for Single-Sided Deafness (CROSSSD) study. Objective: An observational study evaluated the modifications taken by the CROSSSD study team to achieve consensus using web-based methods, but with minimal deviation from the original study protocol. Methods: The study team worked with healthcare users and professionals to translate the planned face-to-face consensus meeting in a web-based format, preserving key elements of the nominal group technique. A follow-up survey gathered evaluation feedback on the experience of the 22 participating members. Feedback covered (i) pre-meeting preparation, (ii) process of facilitated discussions and voting, (iii) ability to contribute, and (iv) perceived fairness of the outcome. Results: Overall, 53 out of 54 feedback responses agreed or strongly agreed with the statements given, indicating the web-based meeting achieved its original goals of open discussion, debate, and voting to agree a core outcome set for single-sided deafness. Hearing-impaired participants were fully engaged, but there were some methodological challenges. For the participants, challenges included building rapport, understanding, and delivering the tasks in hand. For the study team, challenges included the need for thorough preparation and managing the unpredictability of tasks on the day. Conclusion: Sharing our experiences and lessons learned can benefit future core outcome set developers. Overcoming the challenges of delivering a web-based consensus exercise in the face of the pandemic can be applied more generally to maximise inclusiveness, enhance geographical access, as well as to reduce research costs

    Lipid analogs reveal features critical for hemolysis and diminish granadaene mediated Group B Streptococcus infection

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    Although certain microbial lipids are toxins, the structural features important for cytotoxicity remain unknown. Increased functional understanding is essential for developing therapeutics against toxic microbial lipids. Group B Streptococci (GBS) are bacteria associated with preterm births, stillbirths, and severe infections in neonates and adults. GBS produce a pigmented, cytotoxic lipid, known as granadaene. Despite its importance to all manifestations of GBS disease, studies towards understanding granadaene’s toxic activity are hindered by its instability and insolubility in purified form. Here, we report the synthesis and screening of lipid derivatives inspired by granadaene, which reveal features central to toxin function, namely the polyene chain length. Furthermore, we show that vaccination with a non-toxic synthetic analog confers the production of antibodies that inhibit granadaene-mediated hemolysis ex vivo and diminish GBS infection in vivo. This work provides unique structural and functional insight into granadaene and a strategy to mitigate GBS infection, which will be relevant to other toxic lipids encoded by human pathogens.This work was supported by funding from the National Institutes of Health Grants R01AI112619, R01AI133976, R01AI100989, and R21AI125907 and seed funds from Seattle Childrens Research Institute to L.

    Core outcome domains for early-phase clinical trials of sound-, psychology-, and pharmacology-based interventions to manage chronic subjective tinnitus in adults: the COMIT'ID study protocol for using a Delphi process and face-to-face meetings to establish consensus

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    Background: The reporting of outcomes in clinical trials of subjective tinnitus indicates that many different tinnitus-related complaints are of interest to investigators, from perceptual attributes of the sound (e.g. loudness) to psychosocial impacts (e.g. quality of life). Even when considering one type of intervention strategy for subjective tinnitus, there is no agreement about what is critically important for deciding whether a treatment is effective. The main purpose of this observational study is therefore to develop Core Outcome Domain Sets for the three different intervention strategies (sound, psychological, and pharmacological) for adults with chronic subjective tinnitus that should be measured and reported in every clinical trial of these interventions. Secondary objectives are to identify the strengths and limitations of our study design for recruiting and reducing attrition of participants, and to explore uptake of the core outcomes. Methods: The ‘Core Outcome Measures in Tinnitus: International Delphi’ (COMIT’ID) study will use a mixed methods approach that incorporates input from healthcare users at the pre-Delphi stage, a modified three round Delphi survey and final consensus meetings (one for each intervention). The meetings will generate recommendations by stakeholder representatives on agreed Core Outcome Domain Sets specific to each intervention. A subsequent step will establish a common cross-cutting Core Outcome Domain Set by identifying the common outcome domains included in all three intervention-specific Core Outcome Domain Sets. To address the secondary objectives, we will gather feedback from participants about their experience of taking part in the Delphi process. We aspire to conduct an observational cohort study to evaluate uptake of the core outcomes in published studies at 7 years following core outcome set publication. Discussion: The COMIT’ID study aims to develop a Core Outcome Domain Set that are agreed as critically important for deciding whether a treatment for subjective tinnitus is effective. Such a recommendation would help to standardise future clinical trials worldwide and so we will determine if participation increases use of the core outcome set in the long term. Trial registration: This project has been registered in the database of the Core Outcome Measures in Effectiveness Trials (COMET) initiative

    Neoadjuvant endocrine therapy in primary breast cancer: indications and use as a research tool

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    Neoadjuvant endocrine therapy has been increasingly employed in clinical practice to improve surgical options for postmenopausal women with bulky hormone receptor-positive breast cancer. Recent studies indicate that tumour response in this setting may predict long-term outcome of patients on adjuvant endocrine therapy, which argues for its broader application in treating hormone receptor-positive disease. From the research perspective, neoadjuvant endocrine therapy provides a unique opportunity for studies of endocrine responsiveness and the development of novel therapeutic agents
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