Queen Mary, University of London
  • London, United Kingdom
Recent publications
The differential diagnosis of cardiac masses via operation view is an essential step in the management of what is a rare, but potentially debilitating or lethal, group of pathologies. Because most patients with cardiac masses (especially benign masses) are asymptomatic and uncovered incidentally, early detection and diagnosis is challenging. To this end, imaging (across various modalities) plays a vital role in ruling out differentials and in doing so facilitates prompt intervention. Undoubtedly, an appreciation of the surgical features of benign and malignant cardiac masses is also key.
Benign cardiac masses are a rare entity and are characterized by their propensity to present under the guise of clinical manifestations also associated with other more common and lethal syndromes. Apart from this, the majority of patients with benign cardiac masses are asymptomatic, and detection is often incidental or at postmortem. Imaging and biopsy are the mainstay of diagnosis for such masses; therefore, an appreciation of the surgical features thereof is vital. The majority of benign cardiac masses can be curatively treated by prompt surgical excision.
Background Although prior reports have evaluated the clinical and cost impacts of cardiovascular magnetic resonance (CMR) for low-to-intermediate-risk patients with suspected significant coronary artery disease (CAD), the cost-effectiveness of CMR compared to relevant comparators remains poorly understood. We aimed to summarize the cost-effectiveness literature on CMR for CAD and create a cost-effectiveness calculator, useable worldwide, to approximate the cost-per-quality-adjusted-life-year (QALY) of CMR and relevant comparators with context-specific patient-level and system-level inputs. Methods We searched the Tufts Cost-Effectiveness Analysis Registry and PubMed for cost-per-QALY or cost-per-life-year-saved studies of CMR to detect significant CAD. We also developed a linear regression meta-model (CMR Cost-Effectiveness Calculator) based on a larger CMR cost-effectiveness simulation model that can approximate CMR lifetime discount cost, QALY, and cost effectiveness compared to relevant comparators [such as single-photon emission computed tomography (SPECT), coronary computed tomography angiography (CCTA)] or invasive coronary angiography. Results CMR was cost-effective for evaluation of significant CAD (either health-improving and cost saving or having a cost-per-QALY or cost-per-life-year result lower than the cost-effectiveness threshold) versus its relevant comparator in 10 out of 15 studies, with 3 studies reporting uncertain cost effectiveness, and 2 studies showing CCTA was optimal. Our cost-effectiveness calculator showed that CCTA was not cost-effective in the US compared to CMR when the most recent publications on imaging performance were included in the model. Conclusions Based on current world-wide evidence in the literature, CMR usually represents a cost-effective option compared to relevant comparators to assess for significant CAD.
Background The validity of ratings of perceived exertion (RPE) during aerobic training is well established; however, its validity during resistance exercise is less clear. This meta-analysis used the known relationships between RPE and exercise intensity (EI), heart rate (HR), blood lactate (BLa), blood pressure (BP) and electromyography (EMG) to determine the convergent validity of RPE as a measure of resistance exercise intensity and physiological exertion, during different forms of resistance exercise. Additionally, this study aims to assess the effect of several moderator variables on the strength of the validity coefficients, so that clearer guidance can be given on the use of RPE during resistance exercise. Methods An online search of 4 databases and websites (PubMed, Web of Science SPORTDiscus and ResearchGate) was conducted up to 28 February 2020. Additionally, the reference lists of the included articles were inspected manually for further unidentified studies. The inclusion criteria were healthy participants of any age, a rating scale used to measure RPE, resistance exercise of any type, one cohort receiving no other intervention, and must present data from one of the following outcome measures: EI, HR, BP, EMG or BLa. Weighted mean effect sizes ( r ) were calculated using a random-effects model. Heterogeneity was assessed using the τ ² and I ² statistics. Moderator analysis was conducted using random-effects meta-regression. Results One-hundred and eighteen studies were included in the qualitative synthesis, with 75 studies (99 unique cohorts) included in the meta-analysis. The overall weighted mean validity coefficient was large (0.88; 95% CI 0.84–0.91) and between studies heterogeneity was very large ( τ ² = 0.526, I ² = 96.1%). Studies using greater workload ranges, isometric muscle actions, and those that manipulated workload or repetition time, showed the highest validity coefficients. Conversely, sex, age, training status, RPE scale used, and outcome measure no significant effect. Conclusions RPE provides a valid measure of exercise intensity and physiological exertion during resistance exercise, with effect sizes comparable to or greater than those shown during aerobic exercise. Therefore, RPE may provide an easily accessible means of prescribing and monitoring resistance exercise training. Trial Registration The systematic review protocol was registered on the PROSPERO database (CRD42018102640).
Sediment microbial communities drive the biogeochemical cycles that make rivers globally important sources and sinks of carbon (C) and nitrogen (N). The structure of these communities is strongly determined by the local physico-chemical environment. However, we currently lack an understanding of the factors that determine microbial community structures at the catchment scale. Here, we show that the contribution of groundwater to total river flow (quantified as base flow index; BFI) predicts the structure and diversity of the different microbial functional groups that cycle N and C across nine UK rivers, spanning a geological BFI gradient from 0.23 (clay sediment) to 0.95 (chalk gravel sediment). Furthermore, the GC-content (percentage of guanine-cytosine bases in a DNA sequence) and codon-usage bias of ammonia monooxygenase DNA sequences, and the hydrophobicity and net-charge of the corresponding amino acid sequences, were all strongly correlated with BFI, likely reflecting physiological adaptations to different riverbed sediment structure along the BFI gradient. Our results offer an opportunity to overcome the “paradox of scales” that has seen microbial ecologists focus on small- rather than large-scale environmental variables, enabling us to scale-up our understanding of microbial biogeochemistry to the catchment and beyond.
The accurate simulation of additional interactions at the ATLAS experiment for the analysis of proton–proton collisions delivered by the Large Hadron Collider presents a significant challenge to the computing resources. During the LHC Run 2 (2015–2018), there were up to 70 inelastic interactions per bunch crossing, which need to be accounted for in Monte Carlo (MC) production. In this document, a new method to account for these additional interactions in the simulation chain is described. Instead of sampling the inelastic interactions and adding their energy deposits to a hard-scatter interaction one-by-one, the inelastic interactions are presampled, independent of the hard scatter, and stored as combined events. Consequently, for each hard-scatter interaction, only one such presampled event needs to be added as part of the simulation chain. For the Run 2 simulation chain, with an average of 35 interactions per bunch crossing, this new method provides a substantial reduction in MC production CPU needs of around 20%, while reproducing the properties of the reconstructed quantities relevant for physics analyses with good accuracy.
With the rapid development of fifth-generation mobile communication technology and wearable electronic devices, electromagnetic interference and radiation pollution caused by electromagnetic waves have attracted worldwide attention. Therefore, the design and development of highly efficient EMI shielding materials are of great importance. In this work, the three-dimensional graphene oxide (GO) with regular honeycomb structure (GH) is firstly constructed by sacrificial template and freeze-drying methods. Then, the amino functionalized FeNi alloy particles ( f -FeNi) are loaded on the GH skeleton followed by in-situ reduction to prepare rGH@FeNi aerogel. Finally, the rGH@FeNi/epoxy EMI shielding composites with regular honeycomb structure is obtained by vacuum-assisted impregnation of epoxy resin. Benefitting from the construction of regular honeycomb structure and electromagnetic synergistic effect, the rGH@FeNi/epoxy composites with a low rGH@FeNi mass fraction of 2.1 wt% (rGH and f -FeNi are 1.2 and 0.9 wt%, respectively) exhibit a high EMI shielding effectiveness (EMI SE) of 46 dB, which is 5.8 times of that (8 dB) for rGO/FeNi/epoxy composites with the same rGO/FeNi mass fraction. At the same time, the rGH@FeNi/epoxy composites also possess excellent thermal stability (heat-resistance index and temperature at the maximum decomposition rate are 179.1 and 389.0 °C respectively) and mechanical properties (storage modulus is 8296.2 MPa).
Respiratory diseases remain a significant cause of global morbidity and mortality and primary care plays a central role in their prevention, diagnosis and management. An e-Delphi process was employed to identify and prioritise the current respiratory research needs of primary care health professionals worldwide. One hundred and twelve community-based physicians, nurses and other healthcare professionals from 27 high-, middle- and low-income countries suggested 608 initial research questions, reduced after evidence review by 27 academic experts to 176 questions covering diagnosis, management, monitoring, self-management and prognosis of asthma, COPD and other respiratory conditions (including infections, lung cancer, tobacco control, sleep apnoea). Forty-nine questions reached 80% consensus for importance. Cross-cutting themes identified were: a need for more effective training of primary care clinicians; evidence and guidelines specifically relevant to primary care, adaption for local and low-resource settings; empowerment of patients to improve self-management; and the role of the multidisciplinary healthcare team.
Background The efficacy and safety of platelet-rich plasma (PRP) augmentation for arthroscopic meniscal repair is controversial. This meta-analysis compared arthroscopic meniscal repair performed in isolation or augmented with PRP. Methods The present study was conducted according to PRISMA 2020 guidelines. Pubmed, Web of Science, Google Scholar and Embase were accessed in August 2021. All the clinical trials which compared arthroscopic meniscal repair performed in isolation or augmented with PRP were included. Results Eight hundred thirty-seven patients were included: 38% (318 of 837 patients) were women; the mean age of the patients was 35.6 (range, 20.8–64.3) years; the mean follow-up was 26.2 (range, 6–54) months. Similarity was found in analogue scale (VAS) ( P = 0.5) and Lysholm ( P = 0.9), and International Knee Documentation Committee (IKDC) scores ( P = 0.9). Similarity was found in the rate of failure ( P = 0.4) and rate of revision ( P = 0.07). Conclusion The current published scientific evidence does not support PRP augmentation for arthroscopic meniscal repair.
Many disciplines are facing a “reproducibility crisis”, which has precipitated much discussion about how to improve research integrity, reproducibility, and transparency. A unified effort across all sectors, levels, and stages of the research ecosystem is needed to coordinate goals and reforms that focus on open and transparent research practices. Promoting a more positive incentive culture for all ecosystem members is also paramount. In this commentary, we—the Local Network Leads of the UK Reproducibility Network—outline our response to the UK House of Commons Science and Technology Committee’s inquiry on research integrity and reproducibility. We argue that coordinated change is needed to create (1) a positive research culture, (2) a unified stance on improving research quality, (3) common foundations for open and transparent research practice, and (4) the routinisation of this practice. For each of these areas, we outline the roles that individuals, institutions, funders, publishers, and Government can play in shaping the research ecosystem. Working together, these constituent members must also partner with sectoral and coordinating organisations to produce effective and long-lasting reforms that are fit-for-purpose and future-proof. These efforts will strengthen research quality and create research capable of generating far-reaching applications with a sustained impact on society.
The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over the past decade, ATLAS has developed and utilized tools that replace the most CPU-intensive component of the simulation—the calorimeter shower simulation—with faster simulation methods. Here, AtlFast3, the next generation of high-accuracy fast simulation in ATLAS, is introduced. AtlFast3 combines parameterized approaches with machine-learning techniques and is deployed to meet current and future computing challenges, and simulation needs of the ATLAS experiment. With highly accurate performance and significantly improved modelling of substructure within jets, AtlFast3 can simulate large numbers of events for a wide range of physics processes.
Following publication of this article1, it is noticed that some brackets are missing in the mathematical expressions in Fig. 1. Updated Fig. 1 is provided in this Correction.
Background Ecological diversification is the result of divergent natural selection by contrasting habitat characteristics that favours the evolution of distinct phenotypes. This process can happen in sympatry and in allopatry. Habitat-specific parasite communities have the potential to drive diversification among host populations by imposing selective pressures on their host's immune system. In particular, the hyperdiverse genes of the major histocompatibility complex (MHC) are implicated in parasite-mediated host divergence. Here, we studied the extent of divergence at MHC, and discuss how it may have contributed to the Nicaraguan Midas cichlid species complex diversification, one of the most convincing examples of rapid sympatric parallel speciation. Results We genotyped the MHC IIB for individuals from six sympatric Midas cichlid assemblages, each containing species that have adapted to exploit similar habitats. We recovered large allelic and functional diversity within the species complex. While most alleles were rare, functional groups of alleles (supertypes) were common, suggesting that they are key to survival and that they were maintained during colonization and subsequent radiations. We identified lake-specific and habitat-specific signatures for both allelic and functional diversity, but no clear pattern of parallel divergence among ecomorphologically similar phenotypes. Conclusions Colonization and demographic effects of the fish could have contributed to MHC evolution in the Midas cichlid in conjunction with habitat-specific selective pressures, such as parasites associated to alternative preys or environmental features. Additional ecological data will help evaluating the role of host–parasite interactions in the Midas cichlid radiations and aid in elucidating the potential role of non-parallel features differentiating crater lake species assemblages.
Background There has been a growing interest in imageless navigation for primary total hip arthroplasty (THA). Its superiority over standard THA is debated. This meta-analysis compared surgical duration, implant positioning, Harris Hip Score and rate of dislocation of imageless navigation versus conventional THA. Methods The present study was conducted according to the PRISMA 2020 guidelines. All the clinical trials comparing imageless navigation versus conventional for primary THA were accessed. In January 2022, the following databases were accessed: PubMed, Web of Science, Google Scholar and Embase. No time constraints were used for the search. The outcomes of interest were to compare cup inclination and anteversion, leg length discrepancy, surgical duration, Harris Hip Score and rate of dislocation of imageless navigation versus conventional THA. Results Twenty-one studies (2706 procedures) were retrieved. Fifty-two percent of patients were women. There was between-group comparability at baseline in terms of age, body mass index (BMI), visual analogue scale, Harris Hip Score and leg length discrepancy ( P > 0.1). Compared with conventional THA, the navigated group demonstrated slightly lower leg length discrepancy ( P = 0.02) but longer duration of the surgical procedure ( P < 0.0001). Cup anteversion ( P = 0.6) and inclination ( P = 0.5), Harris Hip Score ( P = 0.1) and rate of dislocation ( P = 0.98) were similar between the two interventions. Conclusion Imageless navigation may represent a viable option for THA.
Objective To produce a guide for dentists and orthodontists to determine orthodontic treatment need in borderline cases (dental health component DHC 3) and to compare views of different panels of judges on treatment need. Materials and methods Prospective, observational study. Photographs of one hundred subjects displaying borderline occlusal traits (DHC3) were collected. Three panels of judges consisting of 25 orthodontists, 25 dentists and 25 lay persons assessed photographs based on orthodontic treatment need on aesthetic grounds. Results Spearman’s correlation coefficient showed no statistical difference between the panels of judges ( p < 0.001). The judges identified a ‘high need’ for treatment on aesthetic grounds for those with anterior open bites and reverse overjets. Kappa analysis showed moderate intra-rater agreement for the orthodontic and dental panels of judges ( k = 0.47 and 0.45, respectively) and fair agreement ( k = 0.26) for the lay panel, highlighting the intrinsic difficulty of assessing borderline malocclusions. Conclusion There was no statistical difference in the way the orthodontic, dental and lay panels of judges perceived treatment need for DHC 3 cases. Anterior open bites and reverse overjets were predominantly found to be in high need of treatment by all panels of judges. A ‘Guide to Borderline Orthodontic Need’ (GBON) is proposed consisting of 8 photographs of subjects with borderline occlusal traits (DHC3) determined unambiguously by lay, dental and orthodontic panels as either ‘needing’ or ‘not needing’ orthodontic treatment on aesthetic grounds. It is anticipated that this will assist users to make judgments on aesthetic grounds on the need for treatment in borderline cases.
Background Sex differences are known to play a role in disease aetiology, progression and outcome. Previous studies have revealed autosomal epigenetic differences between males and females in some tissues, including differences in DNA methylation patterns. Here, we report for the first time an analysis of autosomal sex differences in DNAme using the Illumina EPIC array in human whole blood by performing a discovery ( n = 1171) and validation ( n = 2471) analysis. Results We identified and validated 396 sex-associated differentially methylated CpG sites (saDMPs) with the majority found to be female-biased CpGs (74%). These saDMP’s are enriched in CpG islands and CpG shores and located preferentially at 5’UTRs, 3’UTRs and enhancers. Additionally, we identified 266 significant sex-associated differentially methylated regions overlapping genes, which have previously been shown to exhibit epigenetic sex differences, and novel genes. Transcription factor binding site enrichment revealed enrichment of transcription factors related to critical developmental processes and sex determination such as SRY and ESR1. Conclusion Our study reports a reliable catalogue of sex-associated CpG sites and elucidates several characteristics of these sites using large-scale discovery and validation data sets. This resource will benefit future studies aiming to investigate sex specific epigenetic signatures and further our understanding of the role of DNA methylation in sex differences in human whole blood.
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22,995 members
Rachel Crespo
  • School of Biological and Chemical Sciences
Ildar Farkhatdinov
  • School of Electronic Engineering and Computer Science
Ahmad Waseem
  • Centre for Clinical and Diagnostic Oral Sciences
Ozge Eyice
  • School of Biological and Chemical Sciences
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