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Reconfigurable plasma frequency selective surface
No full textThis paper presents single- and double-layer reconfigurable frequency selective surfaces (FSS) for high-power microwave (HPM) shielding, utilizing plasma as an active element. Unlike conventional FSS, plasma-based design enables tunable filtering by adjusting plasma density or shape, reducing the need for extensive structural modifications. Plasma elements enhance shielding, offer reconfigurability (ON mode), and can be rendered transparent when the plasma is deactivated (OFF mode). The proposed FSS utilizes plasma formation, induced by HPM-generated electric fields, to selectively absorb electromagnetic (EM) energy. Simulation results indicate excellent isolation, with insertion loss exceeding 10 dB across the target frequency band as input power increases. This approach offers promising capabilities for dynamic EM power reception control and equipment shielding in high-power environments.<br/
Cost benefit analysis of the enhancing men's awareness of testicular diseases (E-MAT) feasibility trial: a virtual reality experience to increase testicular knowledge and self-examination among male athletes
No full textBackgroundVirtual reality (VR) is potentially effective in raising awareness of testicular diseases, promoting self-examination and early help-seeking among men. This paper presents an early economic evaluation exploring the potential cost-effectiveness of Enhancing Men’s Awareness of Testicular diseases (E-MAT)VR, a VR interactive experience compared with E-MATE, electronic information, among male athletes Results from this economic evaluation will inform and support the design of a future randomized controlled trial (RCT).MethodsResults from an Irish feasibility trial (ClinicalTrials.gov identifier: NCT05146466) with 74 participants conducted in 2022 were employed. Benefits were measured in monetary units whereby the contingent valuation method was used to elicit participants’ preferences through willingness-to-pay measures. A micro-cost analysis estimated the costs of the intervention and comparator and subsequent resource use. The costs and benefits of E-MATVR and E-MATE were compared to determine the net benefit. Sensitivity analyses were also conducted.ResultsBase case analysis suggests participants were willing to pay €21.88 for E-MATVR and €11.16 for E-MATE. The total cost of E-MATVR was €104.09 and of E-MATE was €22.75 per participant. These estimates include capital and delivery costs, of which delivery costs were €25.02 and €22.40 for E-MATVR and E-MATE, respectively. A negative net benefit indicates E-MATVR was not cost-beneficial as delivered in the feasibility trial. Scenario analyses demonstrated reducing costs via delivery modifications increased the probability of E-MATVR being considered cost-effective. The cost–benefit analysis was feasible, response rates were acceptable, and willingness-to-pay estimates were stable.ConclusionsEconomic evaluations alongside feasibility trials enable early economic evaluations, informing the design and conduct of a future RCT. E-MATVR had higher expected benefits (WTP) and costs than E-MATE, yielding a negative net benefit. Given the high cost of digital health interventions, investigating their cost-effectiveness early is important to inform and optimize resource allocation decisions. We present a series of scenarios to demonstrate how delivery modifications to reduce costs could improve the likelihood of E-MATVR being considered cost-effective
On Muckross Head. Garrett Carr remembers the coast around his hometown in the north west of Ireland
No full textI spent a lot of my youth adrift; living and working across many parts of the world, but I didn’t experience homesickness until I was about 29. It took me a while to diagnose myself as the homesickness was manifested abstractly and came and went in quick flashes. I wouldn’t have expected homesickness..
Film on the artworks 'Dreams and Chaos' by Archee Roy
No full textThe short film is 4 minutes and 21 seconds long. It acts as documentation, and evocation, of artworks created as part of a research project. It includes brief information about the source material provided to the artist, to inform their creative arts research, and some of the reflections of the artist about the artwork made. Stills and video footage of the artwork are stitched together in relation to the text. As indicated in the references below, the artwork shown here is 'Dreams and Chaos'by Archee Roy. Ink, wax, acrylic on cotton canvas. Six pieces, combined at 72x48inches.The artworks were created for a collaborative research project, which were shown as part of the exhibition 'Counter-Narrative of Authority in Transition: Marginality in the Indian Academy', led by Prof Dina Zoe Belluigi (Queen’s University Belfast, Northern Ireland) and Dr Nandita Banerjee Dhawan (Jadavpur University, India), in collaboration with Dr Asha Achuthan (Tata Institute of Social Sciences, India) and Dr Ulrike M. Vieten (Queen’s University Belfast, Northern Ireland). See references below for the link to that exhibition.The short film, and a transcript of the text within the film, are included in this data set. The film was edited by Brent Arthur MeistreFootage was provided by the artistFootage, details of the artwork, and installation views were provided by Dina Zoe Belluigi CC BY-NC-ND 2025 Belluigi, Dhawan, Achuthan and Viete
Comparative analysis of Maxwell solvers for simulation of relativistic harmonic generation in particle-in-cell code
No full textWith advances in laser technology reaching the multipetawatt era, the expanding experimental prospects for high-order harmonic generation from solid targets prompt more rigorous particle-in-cell (PIC) simulation campaigns for elucidating the generation mechanisms. However, accurately representing a broad range of high frequencies in multidimensional simulations remains challenging. The commonly employed finite difference time domain (FDTD) method, the Yee stencil, introduces artificial numerical dispersion, inducing unphysical angular deviation of higher-order harmonics. This paper uses EPOCH and WarpX PIC codes to present a comprehensive analysis of numerical dispersion mitigation for two-dimensional (2D) simulations of high-order harmonic generation. Results conclude that carefully orienting high-frequency elements within the 2D simulated grid for the standard FDTD scheme can provide significant accuracy improvements at moderate resolution and computational power for cases with a distinct propagation direction for the electromagnetic radiation of interest. This study also evaluates higher-order pseudospectral analytical time-domain (PSATD) solvers, which eliminate angular deviations across all tested angles of incidence and promise to enhance scalability in exascale computing environments
Investigating the accuracy of neural networks for blood pressure prediction in the ICU
No full textThis paper reports on research which investigates the viability of artificial neural networks, used in an ICU environment, for predicting both systolic and diastolic blood pressure up to one hour ahead. In this environment, patients often receive pharmacological intervention to increase or decrease blood pressure. The physiological state of an ICU patient is therefore quite different to a hyper or hypotensive patient outside hospital, suggesting that predicting blood pressure in this environment is more challenging The work investigates whether building neural network architectures with multivariate input data is capable of predicting blood pressures in this environment. Our work uses skin temperature and heart rate readings in addition to systolic and diastolic blood pressure. Two types of neural network are explored are explored in this paper: an encoder-decoder long short-term memory architecture and, separately, a convolutional neural network architecture. The top-performing configuration, when using a 70%−30% train-test split of data, is a convolutional neural network model. This predicted systolic and diastolic blood pressures for a patient with an error of approximately 3.4%. These results are at the same level of accuracy as work on blood pressure prediction outside the ICU environment. Our work shows that neural networks are a viable tool for short term prediction of arterial blood pressures in an ICU context
White light transmission spectroscopy for rapid quality control imperfection identification in nanoimprinted surface-enhanced raman spectroscopy substrates
No full textMiniaturized biomedical sensor development requires improvements in lithographic processes in terms of cost and scalability. Of particular promise is nanoimprint lithography (NIL), but this can suffer from a lack of high-fidelity pattern reproducibility between master and imprinted substrates. Herein, we present a multidisciplinary investigation into gold- and iron-coated NIL sensors including custom optics and spectroscopy, scanning probe microscopy, and data analysis insights. Polyurethane NIL-made nanodome arrays were interrogated with white light transmission spectroscopy, coupled with principal component analysis (PCA) to investigate potential offsets in the photon-substrate plane interaction angle, an imperfection in NIL substrates. Large-angle mismatches (2–10°) were found to be easily discernible by PCA with statistically significant differences (p = 0.05). Unexpected dips in some spectra are postulated to be due to interacting localized and propagating plasmon polaritons, which is supported with a coupled two-oscillator model. General insights are made regarding the interpretation of PCA loadings, which should be related to physical phenomena, and where maximum variance is not necessarily the most meaningful criterion. Smaller angles (<1°) show no significant differences with overlapping confidence intervals in PCA space. Surface-enhanced Raman spectroscopy (SERS) measurements on gold-coated nanodomes returned relative standard deviations of 6–10% via analysis of gelatin, which is of interest as a nasal lining approximation. Interestingly, nanodomes coated in iron produced small, but useful SERS enhancements, which was subsequently interrogated via scanning thermal probe microscopy showing temperature increases of up to 5 °C over the area of one nanostructure (∼1 μm2). Nanostructures remained intact despite the surprising large local temperature increase relative to a gold-coated comparison sample (∼2 °C). The current study provides a framework for the rapid and accurate quality control assessment of imperfections in NIL-produced nanostructures for sensing applications in SERS and surface plasmon resonance, which may need precisely fabricated nanostructures.<br/
A bis-imidazolium receptor for the selective crystallization of fluoride through hydrogen bonding
No full textSelective recognition and separation of fluoride anions from other halides remain significant challenges in supramolecular chemistry due to the similar physicochemical properties of halide ions and the environmental concerns associated with fluoride contamination. We report a simple dicationic bis-imidazolium receptor with hydroxyethyl pendants that selectively binds fluoride ions over other halides through a selective “bidentate” hydrogen bonding mechanism involving C2–H···F– and O–H···F– interactions. This unique binding mode facilitates the crystallization of a fluoride complex from polar solvents containing chloride, bromide, or iodide ions. Despite minimal preorganization, the receptor exhibits size-matched binding pockets that selectively accommodate fluoride ions, enabling their separation from equimolar halide mixtures. This work introduces a new approach to fluoride recognition and offers potential applications in environmental remediation and industrial processes.<br/
Smoking aggravates neovascular age-related macular degeneration via Sema4D-PlexinB1 axis-mediated activation of pericytes
No full textAge-related macular degeneration (AMD) is a prevalent neuroinflammation condition and the leading cause of irreversible blindness among the elderly population. Smoking significantly increases AMD risk, yet the mechanisms remain unclear. Here, we investigate the role of Sema4D-PlexinB1 axis in the progression of AMD, in which Sema4D-PlexinB1 is highly activated by smoking. Using patient-derived samples and mouse models, we discover that smoking increases the presence of Sema4D on the surface of CD8 + T cells that migrate into the choroidal neovascularization (CNV) lesion via CXCL12-CXCR4 axis and interact with its receptor PlexinB1 on choroidal pericytes. This leads to ROR2-mediated PlexinB1 phosphorylation and pericyte activation, thereby disrupting vascular homeostasis and promoting neovascularization. Inhibition of Sema4D reduces CNV and improves the benefit of anti-VEGF treatment. In conclusion, this study unveils the molecular mechanisms through which smoking exacerbates AMD pathology, and presents a potential therapeutic strategy by targeting Sema4D to augment current AMD treatments. </p