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Greater Than 1 THz Bandwidth High Sensitivity On-Chip Terahertz Sensing Achieved Using Spoof Surface Plasmon Polaritons for Trace Substance Analysis
No full textTerahertz (THz) spoof surface plasmon polaritons (SSPPs) can play a key role in ultrasensitive fingerprint sensing of trace substances by the enhanced confinement of the electric field that they provide. However, achieving both high sensitivity and broadband detection simultaneously in such structures remains a significant challenge owing to the necessary trade-off between field confinement and bandwidth. This study demonstrates a sensing chip based on an artificial THz SSPP slow-light waveguide that simultaneously achieves broad bandwidth (up to 1 THz) along with highly sensitive detection achieved by enhancing both field confinement strength and the effective light-matter interaction distance. We use α-lactose monohydrate as a model analyte and show that our SSPP-integrated THz sensing chip detects its characteristic rotational mode at 0.53 THz at concentrations as low as 18 μg/μL, which represents a 4-fold improvement in the detection limit over previous sensors. Repeat measurements show reliable stability and reproducibility for the chip. In operating up to 1 THz, a frequency range of significant interest for the study of quantum excitations in condensed matter systems as well as for terahertz studies of molecular dynamics in polycrystalline materials, our scalable platform is ideal for the study of light–matter interactions in a wide range of advanced material systems
Quantification of the real contact area of a finger-pad during sliding using a novel Optical Coherence Tomography system and the influence of skin thickness
Get PDFUnderstanding the interaction of skin with surfaces is important in many applications such as medicine, bioelectronics and consumer products, depending on the grip, dexterity and feel of the objects. These phenomena are governed by frictional forces, which are intrinsically linked to real area of contact. The real contact area, in turn, is modulated by factors such as skin hydration and topographical roughness of the interacting surfaces. In this work, a new high-resolution Optical Coherence Tomography (OCT) tool due to its ability to penetrate and image the skin layers at high resolution, developed in-house, was used to analyse the real contact area and the stratum corneum (SC) thickness in finger-pad interfaces. Data were compared with a lower-resolution VivoSight® OCT device used in previous work. Forty-seven finger-pad sliding tests against smooth glass were performed with forces ranging from 0.5 – 3N. Post-test analyses of the OCT images captured revealed that the real measured contact area was 54% of the apparent contact area using the high-resolution OCT device in comparison to 63% measured with the VivoSight OCT. This underscores the rationale for employing a high-resolution OCT system, as it enables precise visualisation of the contact perimeter at the tribological interface, thereby facilitating a more accurate quantification of interfacial geometry and contact mechanics. The thickness of the SC was also seen to increase during sliding under the high-resolution OCT device. This resulted from the high skin deformation, which in turn influenced the contact area
Associations between food-related concerns, food security status, and food support use: a secondary analysis of the Food and You 2: wave 6 dataset
Get PDFHousehold food insecurity has previously been associated with psychological distress, and subsequently, poorer diet quality. Further understanding of this relationship is required to improve nutritional outcomes, with food-related concerns suggested as one potential mechanism. Therefore, the current pre-registered (https://osf.io/zd3ak) study conducted cross-sectional secondary analyses of Wave 6 (October 2022–January 2023) of the Food and You 2 survey administered in adults aged 16 years and over across England, Wales, and Northern Ireland (N = 2315), to explore the differential prevalence of food-related concerns in people experiencing food insecurity. Exploratory analyses also identified characteristics of food support users (food bank or social supermarket; N = 467) and quantified associations between food support use and the same food-related concerns. People experiencing marginal (OR = 1.43, p = 0.02) and low food security (OR = 1.51, p = 0.02) (relative to high food security) were significantly more concerned about food prices, but this association was not seen in people experiencing very low food security. Both food bank and social supermarket use were predicted by very low food security (food bank OR = 6.05, p < 0.001; social supermarket OR = 2.40, p = 0.02) and having a long-term health condition (food bank OR = 3.91, p = 0.00; social supermarket OR = 3.17, p = 0.00). Food bank users were less concerned about healthy eating (OR = 0.33, p = 0.00) whereas social supermarket users were less concerned about food prices (relative to non-users) (OR = 0.40, p = 0.01). Food-related concerns, particularly regarding food prices, are differentially associated with food security status and food support use. Findings could support specific interventions to promote better diet quality and improve health and wellbeing in populations experiencing food insecurity
Ages of different shell species associated to vermetid bioconstructions remains and their implications on Mid-to Late-Holocene Brazilian sea-level curves
Get PDFVermetid bioconstructions have been widely used as Holocene paleo-sea level indicators along the Brazilian coast, due to their abundance and accuracy, especially in the case of Petaloconchus varians (d’Orbigny, 1841). Most age determinations for this species have been performed using conventional 14C dating of bulk bioconstruction samples. However, this type of sample may contain several types of carbonate or carbonaceous impurities, including remains of other organisms such as mollusks and barnacles, which can affect the reliability of the age. This work compares previous conventional 14C ages of vermetid bioconstruction bulk samples with 14C AMS ages of shells from different species dated individually. The objectives are: i. To establish the relationship among the ages of different species in order to reveal the direction or tendency of past sea-level changes; ii. To evaluate the error in dating bulk samples; iii. To analyze the reliability of the ages obtained from each species, based on aspects such as purity, alteration and neomorphism. The dating results obtained for fossil shells of different species were in agreement with the relative ages expected based on the observed spatial relationship between them. Tetraclita stalactifera parietal plates were older than overgrowing vermetids shells, and shells of the bivalve Leiosolenus aff. bisulcatus in life position, which perforate the bioconstruction, were younger. The ages of individual shells were older than those obtained by dating bulk vermetid bioconstructions, and this difference increased with the age. Taking the paleolevels previously determined for the studied samples and using the revised ages reported here, we infer that relative sea level in southern Brazil was more than 2 m above present between 6000 and 7000 cal aBP. The differences in ages between bulk and individual shell samples highlight that paleo-sea levels inferred from bulk vermetid remains and respective Holocene sea-level curves need revision. More data for separate species are therefore necessary to improve the accuracy of Holocene sea-level curves from Brazil. Furthermore, methodological care must be taken to avoid the influence of micritic envelopes, bioturbation, biofouling, and cement infill on the age
Care of the dying evaluation (CODE) questionnaire: psychometric appraisal for application in Persian-speaking populations
Get PDFObjectives
To appraise the psychometric properties of the CODE-P1 for its application to assess quality of end-stage care among Iranian patients.
Method
A forward/backward translation procedure was performed to prepare a preliminary draft of CODE-P and its face and content validity were tested by an experts’ panel. The CODE-P was completed in this cross-sectional study by 280 bereaved family members in several hospitals in Ardabil, Iran. Construct validity, internal consistency and reliability were checked.
Results
CODE-P had good face and content validity (mean impact score = 4.01 and CVI = 0.92). EFA identified five factors which worked well in terms of construct validity (factor loadings range from 0.31 to 0.84) and internal consistency (Cronbach’s Alpha = 0.91).
Conclusion
The findings supported psychometric properties of the CODE-P for assessing end-stage care quality in Persian-speaking patients. Its application for end-of-life care quality assessment could provide a base for planning evidence-informed interventions
Exploring taste heterogeneity and substitution patterns in dockless bike-sharing parking preferences
No full textDockless bike-sharing (DBS) is an important sustainable urban transportation mode in many cities but faces challenges with disorderly parking management. This study aims to explore the presence of taste heterogeneity and substitution patterns in DBS users’ parking preferences and to determine how interpersonal variations, alternative-specific attributes, and socio-demographic characteristics affect parking choices. Based on stated-preference data collected in China, a mixed nested logit (Mixed NL) model is employed to account for both inter-alternative correlation and random taste heterogeneity. The results indicate that reducing the distance to parking and increasing monetary fines are more effective in discouraging disorderly parking than offering incentives for orderly parking or adjusting parking fees. Social influence also plays a critical role, as users are more likely to park disorderly when they observe others doing so. Meanwhile, the research also reveals that users are willing to pay an average of 0.8 CNY to reduce the distance to parking by 100 m, and are willing to accept on average an additional 58 m of the distance to parking in exchange for 10 min of free riding time. These insights into DBS users’ parking behaviour enhance the understanding of the effectiveness of possible policy interventions and offer a valuable reference for developing future management strategies
Testing Volcano Deformation Models Against 3D Seismic Reflection Imagery of Ancient Intrusions
Get PDFMagma intrusion often drives uplift of the overburden and free surface. Analytical modeling of such surface uplift at active volcanoes allows us to estimate intrusion geometries and positions, as well as volume and pressure changes; these insights have proven critical to forecasting volcanic unrest and eruptions. However, it is rarely possible to compare geodetic source parameters retrieved from analytical models to known intrusion geometries. Seismic reflection data offer an opportunity to image and quantify ancient, buried intrusion geometries and their overburden deformation (i.e., a forced fold). Here, we use 3D seismic reflection data offshore NW Australia to investigate an Early Cretaceous forced fold developed above a laccolith emplaced at ∼0.6–1 km depth. We remove the effects of post-emplacement, burial-related compaction and estimate surface displacement patterns for the forced fold. Analytical modeling of these surface displacements, using both thin plate bending and elastic half-space solutions, suggest source (intrusion) estimates of position and lateral dimensions are similar to those of the actual laccolith. There are some differences between measurements of the laccolith and modeled source estimates, which we attribute to syn-intrusion space-making mechanisms (e.g., compaction). We particularly find penny shaped crack and rectangular dislocation elastic half-space solutions underestimate source emplacement depth by ∼0.2–0.9 km, probably reflecting a lack of heterogeneity (layering) in our models. Our novel approach highlights seismic reflection data is a powerful tool for understanding and testing how magma emplacement translates into surface deformation at active volcanoes
Insights from aquaporin structures into drug-resistant sleeping sickness
Get PDFTrypanosoma brucei is the causal agent of African trypanosomiasis in humans and animals, the latter resulting in significant negative economic impacts in afflicted areas of the world. Resistance has arisen to the trypanocidal drugs pentamidine and melarsoprol through mutations in the aquaglyceroporin TbAQP2 that prevent their uptake. Here, we use cryogenic electron microscopy to determine the structure of TbAQP2 from T. brucei, bound to either the substrate glycerol or to the sleeping sickness drugs, pentamidine or melarsoprol. The drugs bind within the AQP2 channel at a site completely overlapping that of glycerol. Mutations leading to a drug-resistant phenotype were found in the channel lining. Molecular dynamics (MD) simulations showed the channel can be traversed by pentamidine, with a low energy binding site at the centre of the channel, flanked by regions of high energy association at the extracellular and intracellular ends. Drug-resistant TbAQP2 mutants are still predicted to bind pentamidine, but the much weaker binding in the centre of the channel observed in the MD simulations would be insufficient to compensate for the high energy processes of ingress and egress, hence impairing transport at pharmacologically relevant concentrations. The structures of drug-bound TbAQP2 represent a novel paradigm for drug-transporter interactions and are a new mechanism for targeting drugs in pathogens and human cells
Psychometric properties of health-related quality of life patient reported outcome measures for common cardiovascular conditions:a scoping review and COSMIN analysis
Get PDFAIMS: Health-related quality of life (HRQoL) is an important measure of disease status and represents a holistic approach to delivering patient-centered care. We conducted a scoping review of HRQoL patient reported outcome measures (PROMs) for cardiovascular diseases (CVDs) and evaluated their psychometric properties. METHODS AND RESULTS: Randomized trials and observational studies that developed and validated HRQoL PROMs for adults with ischaemic heart disease (IHD), aortic stenosis (AS), atrial fibrillation (AF), heart failure (HF), or generic CVD were included, published from inception of databases to 8 February 2025 using PubMed, Web of Science, and Embase. Independent reviewers selected and extracted the psychometric properties of each PROM in accordance with the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist: content validity, reliability, internal consistency, structural validity, criterion/convergent, cross-cultural validity, measurement error, hypothesis testing, and responsiveness. Each PROM was graded using the Grading of Recommendations Assessment, Development, and Evaluation approach. Of 9430 articles, 220 studies for 38 different PROMs were included (HF n = 17, 45%; AF n = 11, 29%; IHD n = 7, 18%; generic n = 2, 5%; AS n = 1, 3%). Eleven PROMs (29%) satisfied all nine COSMIN criteria; the majority (n = 19, 50%) required further validation and eight were deemed inadequate for clinical use (21%). CONCLUSION: This scoping review of HRQoL PROMs in individuals with common CVDs found evidence that many PROMs do not fulfill all nine COSMIN criteria for methodological quality, and for some CVDs there is a limited choice of suitable PROMs for HRQoL measurement. There is an opportunity to improve HRQoL evaluation for use within routine care and research
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