1,397 research outputs found
Risk of thromboembolism in patients developing critical illness-associated atrial fibrillation
This is the author accepted manuscript. The final version is available from the Royal College of Physicians via the DOI in this record.Although common, the long-term significance of developing atrial fibrillation (AF) during a period of
critical illness is unclear. We undertook a retrospective cohort analysis to assess the rate of
thromboembolism (TE) in patients developing atrial fibrillation de novo during admission to our
intensive care unit. 1955 patients were followed up (maximum follow-up 1276 days) for the
occurrence of TE, of which 220 (11.3%) had developed AF or atrial flutter during their critical care
admission. There were 11 TE events among the patients with new AF (0.053 events per patientyear),
compared with 18 in the non-AF group (0.0059 events per patient-year). The unadjusted
hazard ratio for TE in patients developing new AF compared with those not developing AF was 8.09
(95% CI 3.08 – 17.19, p<0.001). In patients admitted to critical care, the development of AF appears
to be associated with a significantly increased risk of subsequent thromboembolism
Exploring the potential relationships between microvascular haemodynamics and density in bone: a feasibility study utilising near infrared spectroscopy
This is the author accepted manuscript. The final version is available from UKIO2019 via the link in this recordRoyal College of Radiologist
Understanding student radiographer attrition: Risk factors and strategies
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordIntroduction
Diagnostic student radiographer attrition is reported at 14%, 6% higher than the average for higher education, however, little research has been undertaken on this subject. This study explored risk factors for attrition and strategies that enabled these to be overcome.
Methods
A two-phase study was undertaken. Phase one: data for 579 former student diagnostic radiographers (468 completers and 111 non-completers) from 3 English universities were analysed. Logistic regression was used to estimate odds ratios and 95% confidence intervals for completion based on individual characteristics. Phase two: content analysis of data from an online survey of 186 current UK student diagnostic radiographers exploring their experiences was undertaken.
Results
Phase one: Attrition was 19%. Increased age, non A-level entry qualifications and poor academic performance were predictors of attrition (p < 0.005). Phase two: Challenges reported by groups identified as ‘at risk’ showed that for mature students and those with non-traditional entry qualifications, external responsibilities/pressures and financial pressures were likely to be the greatest cause of attrition and for younger students with traditional qualifications, academic difficulty and excessive workload were most significant. Scientific learning and academic writing were identified as the most common academic difficulties by all groups. Poor mental health may also be a risk factor.
Conclusion
Although characteristics were identified that increased the chance of attrition, the study concluded that attrition is most likely to be multi-factorial. Academic and personal support were identified as key in students continuing their studies when they considered leaving. Clinical placement experience is likely to influence continuation decisions.
Implications for practice
Transparency around course expectations and academic requirements together with ensuring high quality clinical placements may assist in reducing attrition.University of ExeterNational Institute for Health Research (NIHR
Communities as Well Separated Subgraphs With Cohesive Cores: Identification of Core-Periphery Structures in Link Communities
Communities in networks are commonly considered as highly cohesive subgraphs
which are well separated from the rest of the network. However, cohesion and
separation often cannot be maximized at the same time, which is why a
compromise is sought by some methods. When a compromise is not suitable for the
problem to be solved it might be advantageous to separate the two criteria. In
this paper, we explore such an approach by defining communities as well
separated subgraphs which can have one or more cohesive cores surrounded by
peripheries. We apply this idea to link communities and present an algorithm
for constructing hierarchical core-periphery structures in link communities and
first test results.Comment: 12 pages, 2 figures, submitted version of a paper accepted for the
7th International Conference on Complex Networks and Their Applications,
December 11-13, 2018, Cambridge, UK; revised version at
http://141.20.126.227/~qm/papers
Aspects of the analytical ultracentrifuge determination of the molar mass distribution of polysaccharides
Molar mass or ‘molecular weight’ is one of the most fundamental parameters describing a macromolecule. Because of their polydisperse nature, polysaccharides are usually described by distributions of molar mass. SEC-MALS (size exclusion chromatography coupled to multi-angle light scattering) is often a convenient method of choice, but there are many instances where it is unsuitable. Modern AUC (analytical ultracentrifuge) methods provide a valuable alternative – now easier to use than before – and, after briefly reviewing some older procedures, we highlight two recently published and complementary methods, namely, the ‘Extended Fujita’ approach for the analysis of sedimentation velocity data and SEDFIT-MSTAR for the analysis of sedimentation equilibrium data. Nonideality needs to be considered and can be dealt with in a standard way. These methods can also indicate if associative phenomena are present, which can then be quantified using more complex AUC algorithms
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The characteristics of cognitive neuroscience tests in a schizophrenia cognition clinical trial: Psychometric properties and correlations with standard measures.
In comparison to batteries of standard neuropsychological tests, cognitive neuroscience tests may offer a more specific assessment of discrete neurobiological processes that may be aberrant in schizophrenia. However, more information regarding psychometric properties and correlations with standard neuropsychological tests and functional measures is warranted to establish their validity as treatment outcome measures. The N-back and AX-Continuous Performance Task (AX-CPT) are two promising cognitive neuroscience tests designed to measure specific components of working memory and contextual processing respectively. In the current study, we report the psychometric properties of multiple outcome measures from these two tests as well as their correlations with standard neuropsychological measures and functional capacity measures. The results suggest that while the AX-CPT and N-back display favorable psychometric properties, they do not exhibit greater sensitivity or specificity with functional measures than standard neurocognitive tests
Cost-effectiveness of adalimumab for early-stage Dupuytren's disease : an economic evaluation based on a randomized controlled trial and individual-patient simulation model.
This is the final version. Available from British Editorial Society of Bone & Joint Surgery via the DOI in this record. Data sharing:
Aggregate data will be shared at the end of the trial with external researchers who
provide a methodologically sound proposal to the trial team (and will be required
to sign a data sharing access agreement with the sponsor) and in accordance with
the guidelines of the sponsor and funders. Model code may also be available in due
course, on request. Study documents including participant consent form can also
be made available. Requests for data or study documents should be directed to the
corresponding author and will be considered by the chief investigator in conjunction
with other members of the trial management group and the trials unit.AIMS: To estimate the potential cost-effectiveness of adalimumab compared with standard care alone for the treatment of early-stage Dupuytren's disease (DD) and the value of further research from an NHS perspective. METHODS: We used data from the Repurposing anti-TNF for Dupuytren's disease (RIDD) randomized controlled trial of intranodular adalimumab injections in patients with early-stage progressive DD. RIDD found that intranodular adalimumab injections reduced nodule hardness and size in patients with early-stage DD, indicating the potential to control disease progression. A within-trial cost-utility analysis compared four adalimumab injections with no further treatment against standard care alone, taking a 12-month time horizon and using prospective data on EuroQol five-dimension five-level questionnaire (EQ-5D-5L) and resource use from the RIDD trial. We also developed a patient-level simulation model similar to a Markov model to extrapolate trial outcomes over a lifetime using data from the RIDD trial and a literature review. This also evaluated repeated courses of adalimumab each time the nodule reactivated (every three years) in patients who initially responded. RESULTS: The within-trial economic evaluation found that adalimumab plus standard care cost £503,410 per quality-adjusted life year (QALY) gained versus standard care alone over a 12-month time horizon. The model-based extrapolation suggested that, over a lifetime, repeated courses of adalimumab could cost £14,593 (95% confidence interval £7,534 to £42,698) per QALY gained versus standard care alone. If the NHS was willing to pay £20,000/QALY gained, there is a 77% probability that adalimumab with retreatment is the best value for money. CONCLUSION: Repeated courses of adalimumab are likely to be a cost-effective treatment for progressive early-stage DD. The value of perfect parameter information that would eliminate all uncertainty around the parameters estimated in RIDD and the duration of quiescence was estimated to be £105 per patient or £272 million for all 2,584,411 prevalent cases in the UK. Cite this article: Bone Jt Open 2022;3(11):898-906.Wellcome TrustDepartment of Health UK180 Therapeutics LPNational Institute for Health and Care Researc
Renormalisation of heavy-light light ray operators
We calculate the renormalisation of different light ray operators with one
light degree of freedom and a static heavy quark. Both - and
-kernels are considered. A comparison with the light-light case suggests
that the mixing with three-particle operators is solely governed by the light
degrees of freedom. Additionally we show that conformal symmetry is already
broken at the level of the one loop counterterms due to the additional
UV-renormalisation of a cusp in the two contributing Wilson-lines. This general
feature can be used to fix the -renormalisation kernels up to a
constant. Some examples for applications of our results are given.Comment: 23 pages, 5 figures; v2: changed some wording, added a few references
and one appendix concerning some subtleties related to gauge fixing and ghost
terms; v3: clarified calculation in section 3.2., added an explicit
calculation in section 5.2, corrected a few typos and one figure, added a few
comments, results unchanged, except for typesetting matches version to appear
in JHE
Traction forces generated during studded boot‐surface interactions on third‐generation artificial turf: A novel mechanistic perspective
The traction forces generated during studded boot–surface
interactions affect player performance and injury risk. Over
20 years of empirical research into traction on third
generation (3G) artificial turf has met with only limited
success in supporting the development of safer surfaces and
boots. Thus, the purpose of this perspective article is to
present a conceptual framework for generating scientific
understanding on 3G turf traction through a novel
mechanistic approach. A three-stage framework is
proposed. Firstly, the hypothesized traction mechanisms
and related analytical equations are identified, namely:
friction between the boot outsole and surface; shear
resistance of the performance infill layer to the outsole; and
compressive resistance of the performance infill layer to
horizontal stud displacement. Secondly, a Concept Map is
generated to visually represent the contribution of the thirtynine variables identified as directly affecting the traction
response. Finally, a Research Roadmap is constructed to
guide the direction of future traction studies towards the
development of safer surfaces and boots as well as improved
mechanical tests to assess surface safety. The proposed
framework represents the first attempt to deconstruct bootsurface interactions and hypothesize the science behind the
mobilization of traction forces
Evidence based medicine as science
Evidence based medicine has claimed to be science on a number of occasions but it is not clear that this status is deserved. Within philosophy of science four main theories about the nature of science are historically recognised: inductivism, falsificationism, Kuhnian paradigms and research programmes. If evidence based medicine is science knowledge claims should be derived using a process that corresponds to one of these theories. This paper analyses whether this is the case. In the first section, different theories about the nature of science are introduced. In the second section, the claim that evidence based medicine is science is reinterpreted as the claim that knowledge claims derived from randomised controlled trails and meta-analyses are science. In the third section the knowledge claims valued within evidence based medicine are considered from the perspective of inductivism, falsificationism, Kuhnian paradigms and research programmes. In the final section possible counter arguments are considered. It is argued that the knowledge claims valued by evidence based medicine are not justified using inductivism, falsificationism, Kuhnian paradigms or research programmes. If these are the main criteria for evaluating if something is science or not, evidence based medicine does not meet these criteria
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