619 research outputs found

    Study protocol: developing, disseminating, and implementing a core outcome set for selective fetal growth restriction in monochorionic twin pregnancies.

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    BACKGROUND: Selective fetal growth restriction in monochorionic twin pregnancies is associated with an increased risk of perinatal mortality and morbidity and represents a clinical dilemma. Interventions include expectant management with early preterm delivery if there are signs of fetal compromise, selective termination of the compromised twin, fetoscopic laser coagulation of the communicating placental vessels or termination of the whole pregnancy. Previous studies evaluating interventions have reported many different outcomes and outcome measures. Such variation makes comparing, contrasting, and combining results challenging, limiting ongoing research on this uncommon condition to inform clinical practice. We aim to produce, disseminate, and implement a core outcome set for selective fetal growth restriction research in monochorionic twin pregnancies. METHODS: An international steering group, including professionals, researchers, and lay experts, has been established to oversee the development of this core outcome set. The methods have been guided by the Core Outcome Measures in Effectiveness Trials Initiative Handbook. Potential core outcomes will be developed by undertaking a systematic review of studies evaluating interventions for selective fetal growth restriction in monochorionic twin pregnancies. Potential core outcomes will be entered into a three-round Delphi survey and key stakeholders including clinical professionals, researchers, and lay experts will be invited to participate. Repeated reflection and rescoring of individual outcomes should encourage group and individual stakeholder convergence towards consensus outcomes which will be entered into a modified Nominal Group Technique to finalize the core outcome set. Once core outcomes have been agreed, we will establish standardized definitions and recommend high-quality measurement instruments for each outcome. DISCUSSION: The development, dissemination, and implementation of a core outcome set for selective fetal growth restriction should ensure that future research protocols select, collect, and report outcomes and outcome measures in a standardized manner. Data synthesis will be possible on a broad level and rigorous implementation should advance the quality of research studies and their effective use in order to guide clinical practice, improve patient care, maternal, short-term perinatal outcomes, and long-term neurodevelopmental outcomes. TRIAL REGISTRATION: Core Outcome Measures in Effectiveness Trials (COMET) registration number: 998. International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42018092697 . 18th April 2018

    Obstetric anal sphincter injury: a systematic review of information available on the internet.

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    OBJECTIVE: There is no systematic evaluation of online health information pertaining to obstetric anal sphincter injury. Therefore, we evaluated the accuracy, credibility, reliability, and readability of online information concerning obstetric anal sphincter injury. MATERIALS AND METHODS: Multiple search engines were searched. The first 30 webpages were identified for each keyword and considered eligible if they provided information regarding obstetric anal sphincter injury. Eligible webpages were assessed by two independent researchers for accuracy (prioritised criteria based upon the RCOG Third and Fourth Degree Tear guideline); credibility; reliability; and readability. RESULTS: Fifty-eight webpages were included. Seventeen webpages (30%) had obtained Health On the Net certification, or Information Standard approval and performed better than those without such approvals (p = 0.039). The best overall performing website was http://www.pat.nhs.uk (score of 146.7). A single webpage (1%) fulfilled the entire criteria for accuracy with a score of 18: www.tamesidehospital.nhs.uk . Twenty-nine webpages (50%) were assessed as credible (scores ≥7). A single webpage achieved a maximum credibility score of 10: www.meht.nhs.uk . Over a third (21 out of 58) were rated as poor or very poor. The highest scoring webpage was http://www.royalsurrey.nhs.uk (score 62). No webpage met the recommended Flesch Reading Ease Score above 70. The intra-class coefficient between researchers was 0.98 (95% CI 0.96-0.99) and 0.94 (95% CI 0.89-0.96) for accuracy and reliability assessments. CONCLUSION: Online information concerning obstetric anal sphincter injury often uses language that is inappropriate for a lay audience and lacks sufficient accuracy, credibility, and reliability

    Time-sequenced Multi-Radio-Frequency Observations of Cygnus X-3 in Flare

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    Multifrequency observations from the VLA, VLBA and OVRO Millimeter Array of a major radio outburst of Cygnus X-3 in 2001 September are presented, measuring the evolution of the spectrum of the source over three decades in frequency, over a period of six days. Following the peak of the flare, as the intensity declines the high-frequency spectrum at frequency nu steepens from nu^{-0.4} to nu^{-0.6}, after which the spectral index remains at this latter terminal value; a trend previously observed but hitherto not satisfactorily explained. VLBA observations, for the first time, track over several days the expansion of a sequence of knots whose initial diameters are approximately 8 milliarcseconds. The light-crossing time within these plasmons is of the same order as the time-scale over which the spectrum is observed to evolve. We contend that properly accounting for light-travel time effects in and between plasmons which are initially optically thick, but which after expansion become optically thin, explains the key features of the spectral evolution, for example the observed timescale. Using the VLBA images, we have directly measured for the first time the proper motions of individual knots, analysis of which shows a two-sided jet whose axis is precessing. The best-fit jet speed is roughly beta = 0.63 and the precession period is about 5 days, significantly lower than fitted for a previous flare. Extrapolation of the positions of the knots measured by the VLBA back to zero-separation shows this to occur approximately 2.5 days after the detection of the rise in flux density of Cygnus X-3.Comment: 23 pages, 10 figures, accepted by Ap

    Bulk and element specific magnetism of the medium and high entropy Cantor-Wu alloys

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    Magnetic Compton scattering, x-ray magnetic circular dichroism spectroscopy and bulk magnetometry measurements are performed on a set of medium (NiFeCo and NiFeCoCr) and high (NiFeCoCrPd and NiFeCoCrMn) entropy Cantor-Wu alloys. The bulk spin momentum densities determined by magnetic Compton scattering are remarkably isotropic, and this is a consequence of the smearing of the electronic structure by disorder scattering of the electron quasiparticles. Non-zero x-ray magnetic circular dichroism signals are observed for every element in every alloy indicating differences in the populations of the majority and minority spin states implying finite magnetic moments. When Cr is included in the solid solution, the Cr spin moment is unambiguously antiparallel to the total magnetic moment, while a vanishingly small magnetic moment is observed for Mn, despite calculations indicating a large moment. Some significant discrepancies are observed between the experimental bulk and surface magnetic moments. Despite the lack of quantitative agreement, the element specific surface magnetic moments seem to be qualitatively reasonable

    A protocol for developing a core outcome set for ectopic pregnancy

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    BACKGROUND: Randomised controlled trials (RCTs) evaluating ectopic pregnancy have reported many different outcomes, which are themselves often defined and measured in distinct ways. This level of variation results in an inability to compare results of individual RCTs. The development of a core outcome set to ensure outcomes important to key stakeholders are collected consistently will guide future research in ectopic pregnancy. STUDY AIM: To develop and implement a core outcome set to guide future research in ectopic pregnancy. METHODS AND ANALYSIS: We have established an international steering group of key stakeholders, including healthcare professionals, researchers, and individuals with lived experience of ectopic pregnancy. We will identify potential outcomes from ectopic pregnancy from a comprehensive literature review of published randomised controlled trials. We will then utilise a modified Delphi method to prioritise outcomes. Subsequently, key stakeholders will be invited to score potential core outcomes on a nine-point Likert scale, ranging from 1 (not important) to 9 (critical). Repeated reflection and rescoring should promote whole and individual stakeholder group convergence towards consensus ‘core’ outcomes. We will also establish standardised definitions and recommend high-quality measurements for individual core outcomes. TRIAL REGISTRATION: COMET 1492. Registered in November 2019

    A systematic review of outcome and outcome-measure reporting in randomised trials evaluating surgical interventions for anterior-compartment vaginal prolapse: a call to action to develop a core outcome set

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    INTRODUCTION: We assessed outcome and outcome-measure reporting in randomised controlled trials evaluating surgical interventions for anterior-compartment vaginal prolapse and explored the relationships between outcome reporting quality with journal impact factor, year of publication, and methodological quality. METHODS: We searched the bibliographical databases from inception to October 2017. Two researchers independently selected studies and assessed study characteristics, methodological quality (Jadad criteria; range 1-5), and outcome reporting quality Management of Otitis Media with Effusion in Cleft Palate (MOMENT) criteria; range 1-6], and extracted relevant data. We used a multivariate linear regression to assess associations between outcome reporting quality and other variables. RESULTS: Eighty publications reporting data from 10,924 participants were included. Seventeen different surgical interventions were evaluated. One hundred different outcomes and 112 outcome measures were reported. Outcomes were inconsistently reported across trials; for example, 43 trials reported anatomical treatment success rates (12 outcome measures), 25 trials reported quality of life (15 outcome measures) and eight trials reported postoperative pain (seven outcome measures). Multivariate linear regression demonstrated a relationship between outcome reporting quality with methodological quality (β = 0.412; P = 0.018). No relationship was demonstrated between outcome reporting quality with impact factor (β = 0.078; P = 0.306), year of publication (β = 0.149; P = 0.295), study size (β = 0.008; P = 0.961) and commercial funding (β = -0.013; P = 0.918). CONCLUSIONS: Anterior-compartment vaginal prolapse trials report many different outcomes and outcome measures and often neglect to report important safety outcomes. Developing, disseminating and implementing a core outcome set will help address these issues

    Vascular responses of the extremities to transdermal application of vasoactive agents in Caucasian and African descent individuals

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    This is an accepted manuscript of an article published by Springer in European Journal of Applied Physiology on 04/04/2015, available online: https://doi.org/10.1007/s00421-015-3164-2 The accepted version of the publication may differ from the final published version.© 2015, Springer-Verlag Berlin Heidelberg. Purpose: Individuals of African descent (AFD) are more susceptible to non-freezing cold injury than Caucasians (CAU) which may be due, in part, to differences in the control of skin blood flow. We investigated the skin blood flow responses to transdermal application of vasoactive agents. Methods: Twenty-four young males (12 CAU and 12 AFD) undertook three tests in which iontophoresis was used to apply acetylcholine (ACh 1 w/v %), sodium nitroprusside (SNP 0.01 w/v %) and noradrenaline (NA 0.5 mM) to the skin. The skin sites tested were: volar forearm, non-glabrous finger and toe, and glabrous finger (pad) and toe (pad). Results: In response to SNP on the forearm, AFD had less vasodilatation for a given current application than CAU (P = 0.027–0.004). ACh evoked less vasodilatation in AFD for a given application current in the non-glabrous finger and toe compared with CAU (P = 0.043–0.014) with a lower maximum vasodilatation in the non-glabrous finger (median [interquartile], AFD n = 11, 41[234] %, CAU n = 12, 351[451] %, P = 0.011) and non-glabrous toe (median [interquartile], AFD n = 9, 116[318] %, CAU n = 12, 484[720] %, P = 0.018). ACh and SNP did not elicit vasodilatation in the glabrous skin sites of either group. There were no ethnic differences in response to NA. Conclusion: AFD have an attenuated endothelium-dependent vasodilatation in non-glabrous sites of the fingers and toes compared with CAU. This may contribute to lower skin temperature following cold exposure and the increased risk of cold injuries experienced by AFD.Published versio
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