1,805 research outputs found
Development and preliminary evaluation of a clinical guidance programme for the decision about prophylactic oophorectomy in women undergoing a hysterectomy
Objectives: To develop a decision analysis based and computerised clinical guidance programme
(CGP) that provides patient specific guidance on the decision whether or not to undergo a prophylactic
oophorectomy to reduce the risk of subsequent ovarian cancer and to undertake a preliminary pilot
and evaluation.
Subjects: Women who had already agreed to have a hysterectomy who otherwise had no ovarian
pathology.
Setting: Oophorectomy decision consultation at the outpatient or pre-admission clinic.
Methods: A CGP was developed with advice from gynaecologists and patient groups, incorporating
a set of Markov models within a decision analytical framework to evaluate the benefits of undergoing
a prophylactic oophorectomy or not on the basis of quality adjusted life expectancy, life expectancy,
and for varying durations of hormone replacement therapy. Sensitivity analysis and preliminary testing
of the CGP were undertaken to compare its overall performance with established guidelines and practice.
A small convenience sample of women invited to use the CGP were interviewed, the interviews
were taped and transcribed, and a thematic analysis was undertaken.
Results: The run time of the programme was 20 minutes, depending on the use of opt outs to default
values. The CGP functioned well in preliminary testing. Women were able to use the programme and
expressed overall satisfaction with it. Some had reservations about the computerised format and some
were surprised at the specificity of the guidance given.
Conclusions: A CGP can be developed for a complex healthcare decision. It can give evidence-based
health guidance which can be adjusted to account for individual risk factors and reflects a patient’s
own values and preferences concerning health outcomes. Future decision aids and support systems
need to be developed and evaluated in a way which takes account of the variation in patients’ preferences
for inclusion in the decision making process
Relation between socioeconomic deprivation and death from a first myocardial infarction in Scotland: population based analysis
No abstract available
Using cascading Bloom filters to improve the memory usage for de Brujin graphs
De Brujin graphs are widely used in bioinformatics for processing
next-generation sequencing data. Due to a very large size of NGS datasets, it
is essential to represent de Bruijn graphs compactly, and several approaches to
this problem have been proposed recently. In this work, we show how to reduce
the memory required by the algorithm of [3] that represents de Brujin graphs
using Bloom filters. Our method requires 30% to 40% less memory with respect to
the method of [3], with insignificant impact to construction time. At the same
time, our experiments showed a better query time compared to [3]. This is, to
our knowledge, the best practical representation for de Bruijn graphs.Comment: 12 pages, submitte
A two-strain model of infectious disease spread with asymmetric temporary immunity periods and partial cross-immunity
We introduce a two-strain model with asymmetric temporary immunity periods
and partial cross-immunity. We derive explicit conditions for competitive
exclusion and coexistence of the strains depending on the strain-specific basic
reproduction numbers, temporary immunity periods, and degree of cross-immunity.
The results of our bifurcation analysis suggest that, even when two strains
share similar basic reproduction numbers and other epidemiological parameters,
a disparity in temporary immunity periods and partial or complete
cross-immunity can provide a significant competitive advantage. To analyze the
dynamics, we introduce a quasi-steady state reduced model which assumes the
original strain remains at its endemic steady state. We completely analyze the
resulting reduced planar hybrid switching system using linear stability
analysis, planar phase-plane analysis, and the Bendixson-Dulac criterion. We
validate both the full and reduced models with COVID-19 incidence data,
focusing on the Delta (B.1.617.2), Omicron (B.1.1.529), and Kraken (XBB.1.5)
variants. These numerical studies suggest that, while early novel strains of
COVID-19 had a tendency toward dramatic takeovers and extinction of ancestral
strains, more recent strains have the capacity for co-existence.Comment: 29 pages, 18 figure
Association between exposure to environmental tobacco smoke and biomarkers of oxidative stress among patients hospitalised with acute myocardial infarction
Objective
To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction.<p></p>
Design
An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction.<p></p>
Setting
Nine acute hospitals in Scotland.<p></p>
Participants
Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine ≥3.0 ng/mL) were compared with 60 never smokers who had not (admission serum cotinine ≤0.1 ng/mL).<p></p>
Intervention
None.<p></p>
Main outcome measures
Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA) and oxidised low-density lipoprotein (ox-LDL)) were measured on admission blood samples and adjusted for potential confounders.<p></p>
Results
After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031) and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001) but not ox-LDL (beta coefficient 2.14, 95% CI −8.94, 13.21, p = 0.703).<p></p>
Conclusions
Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.<p></p>
The development and applications of ultrafast electron nanocrystallography
We review the development of ultrafast electron nanocrystallography as a
method for investigating structural dynamics for nanoscale materials and
interfaces. Its sensitivity and resolution are demonstrated in the studies of
surface melting of gold nanocrystals, nonequilibrium transformation of graphite
into reversible diamond-like intermediates, and molecular scale charge
dynamics, showing a versatility for not only determining the structures, but
also the charge and energy redistribution at interfaces. A quantitative scheme
for three-dimensional retrieval of atomic structures is demonstrated with
few-particle (< 1000) sensitivity, establishing this nanocrystallographic
method as a tool for directly visualizing dynamics within isolated
nanomaterials with atomic scale spatio-temporal resolution.Comment: 33 pages, 17 figures (Review article, 2008 conference of ultrafast
electron microscopy conference and ultrafast sciences
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