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The effect of inter- and intra-layer delay time on TPU parts fabricated by laser powder bed fusion
Get PDFIn polymer laser powder bed fusion (PBF-LB-P) techniques, such as laser sintering, the time between scanning a given point in one layer and the same x-y point in the next layer is known as the ‘inter-layer delay time’. Multiple parts are normally fabricated in a PBF-LB-P build for efficiency; however, this leads to variation in the inter-layer delay time for individual parts; in this study, we present a specific investigation using a commercially available thermoplastic polyurethane (TPU). Multiple part layouts were used and the resulting parts were subject to tensile testing and fracture surface analysis. The results demonstrate that an increase in inter-layer delay time can lead to a significant reduction in mechanical properties. Fabricating specimens in groups of 5 led to a 10% reduction in ultimate tensile strength, 30% reduction in extension at break, and 15% reduction in Young’s modulus compared to specimens fabricated individually. Fractography suggests this is due to decreased inter-layer bonding and an increase in defects. This has significant implications for the production of multiple parts in a build where consistent mechanical properties are critical. Based on our understanding of this detrimental effect, we put forward a novel build packing approach for PBF-LB-P, based on scanning area equivalence rather than the conventional time minimisation, to mitigate against it
The Potential of Poetry in Mental Health Nurse Pre-registration Education
Get PDFThis paper examines the potential of poetry as a resource within mental health nurse pre-registration education. There has long been a debate as to whether the art or the science of nursing should be foregrounded within pre-registration education, especially in the UK within recent years as the latest Nursing and Midwifery Council's standards of pre-registration education appear to have shifted the focus towards the acquisition of skills, giving less consideration to the holistic transformatory process of education. The paper uses the conceptualisation of education by Beista, who proposes that education can be considered in relation to the three domains of qualification, socialisation and subjectification. Qualification refers to the acquisition of knowledge and skills, socialisation refers to the process of joining a professional group, and subjectification refers to the development of the individual as a reflective, thoughtful and responsible individual. The paper explores each of these domains in turn and considers how poetry can make a unique contribution in supporting both personal development, and the acquisition of professional knowledge and skills. The reading and writing of poetry can support students to challenge epistemic blinders, enhance their interpersonal skills and develop a more authentic professional identity
Chlorpyrifos Acts as a Positive Modulator and an Agonist of N-Methyl-d-Aspartate (NMDA) Receptors: A Novel Mechanism of Chlorpyrifos-Induced Neurotoxicity
Get PDFChlorpyrifos (CPF) is a broad-spectrum organophosphate insecticide. Long-term exposure to low levels of CPF is associated with neurodevelopmental and neurodegenerative disorders. The mechanisms leading to these effects are still not fully understood. Normal NMDA receptor (NMDAR) function is essential for neuronal development and higher brain functionality, while its inappropriate stimulation results in neurological deficits. Thus, the current study aimed to investigate the role of NMDARs in CPF-induced neurotoxicity. We show that NMDARs mediate CPF-induced excitotoxicity in differentiated human fetal cortical neuronal ReNcell CX stem cells. In addition, by using two-electrode voltage clamp electrophysiology of Xenopus oocytes expressing NMDARs, we show CPF potentiation of both GluN1-1a/GluN2A (EC50 ≈ 40 nM) and GluN1-1a/GluN2B (EC50 ≈ 55 nM) receptors, as well as reductions (approximately halved) in the NMDA EC50s and direct activation by 10 μM CPF of both receptor types. In silico molecular docking validated CPF’s association with NMDARs through relatively high affinity binding (−8.82 kcal/mol) to a modulator site at the GluN1–GluN2A interface of the ligand-binding domains
An umbrella review of patient- and carer-reported measures for assessing adult end-of-life care quality outcomes
Get PDFBackground: Assessing end-of-life care quality is important yet selecting measures remains challenging. This umbrella review synthesizes evidence on measures for EOL outcomes—quality of life (QOL), care experience, quality of dying (QOD), and suffering. Methods: We searched five databases for systematic reviews published, 01 January 2009–29 July 2025. Included reviews assessed QOL, care experience, QOD and suffering measures for terminally ill adults and caregivers. We used AMSTAR2 to assess review quality and reported psychometrics per COSMIN. This study is registered on PROSPERO (CRD42024610359). Findings: From 30 reviews, we extracted 161 unique measures: 83 for QOL, 49 for care experience, 15 for QOD, and 14 for suffering. No single measure showed sufficient psychometric robustness. Among generic measures, those with stronger evidence included Palliative Care Outcome Scale (QOL); Family Assessment of Treatment at End-of-life, Care of the Dying Evaluation, and Quality of End-of-Life Care (care experience); Quality of Dying and Death Questionnaire (QOD); and Pictorial Representation of Illness and Self-Measure, and Patient Dignity Inventory (suffering). Interpretation: In this review, we recommended measures with stronger evidence and developed a checklist to guide selection based on domain relevance, disease group, population fit, and psychometrics. Future research should pursue rigorous validation and standardized reporting to strengthen assessment of end-of-life care. Funding: None
Single photonic qutrit in a collective Rydberg polariton
Get PDFQutrit with highly efficient algorithms and security is imperative in quantum information processing. Here, we demonstrate for the first time the coherent creation, control, and readout of a single photonic qutrit in a cold Rydberg ensemble. In each measurement, an optical photon is stored as a Rydberg polariton through electromagnetically induced transparency. Employing two microwave fields, the polariton is driven into an arbitrary superposition of three collective states, each encoded in a Rydberg state. The collective state is mapped into a photonic time-bin qutrit with the microwave field and read out sequentially. The complete sequence, including preparation, control, and readout, is less than 1.8µs, which mitigates decoherence significantly. We measure the coherence of the qutrit with nondestructive Ramsey interferometry, which is preferable for quantum information processing, and find good quantitative agreement with the theoretical model. The ability to write, process, and read out the single photonic qutrit on microsecond timescales with microwave-coupled Rydberg states demonstrates the coherent connectivity among the high Hilbert space of the qutrit. Our study is an important step in exploring qutrit-based quantum information processes and quantum simulation of topological physics with microwave-coupled Rydberg atom ensembles
First upper limits on the 21-cm signal power spectrum of neutral hydrogen at z = 9.16 from the LOFAR 3C 196 field
Get PDFThe redshifted 21-cm signal of neutral hydrogen from the Epoch of Reionization (EoR) can potentially be detected using low-frequency radio instruments such as the Low-Frequency Array (LOFAR). So far, LOFAR upper limits on the 21-cm signal power spectrum have been published using a single target field: the North Celestial Pole (NCP). In this work, we analyse and provide upper limits for the 3C 196 field, observed by LOFAR, with a strong ≈80 Jy source in the centre. This field offers advantages such as higher sensitivity due to zenith-crossing observations and reduced geostationary radio-frequency interference, but also poses challenges due to the presence of the bright central source. After constructing a wide-field sky model, we process a single 6-hour night of 3C 196 observations using direction-independent and direction-dependent calibration, followed by a residual foreground subtraction with a machine learned Gaussian process regression (ML-GPR). A bias correction is necessary to account for signal suppression in the GPR step. Still, even after this correction, the upper limits are a factor of two lower than previous single-night NCP results, with a lowest 2σ upper limit of (146.61 mK)2 at redshift z = 9.16 and wavenumber k = 0.078 h cMpc−1 (with dk/k ≈ 0.3). The results also reveal an excess power, different in behaviour from that observed in the NCP field, suggesting a potential residual foreground origin. In future work, the use of multiple nights of 3C 196 observations combined with improvements to sky modelling and ML-GPR to avoid the need for bias correction should provide tighter constraints per unit observing time than the NCP
An Experimental and Theoretical Study of the Valence Shell Electronic Structure of Nitromethane
Get PDFVibrationally resolved CH3NO2 and CD3NO2 photoelectron spectra and angular distribution parameters, β, have been measured in the photon energy range 20-80 eV. This allows a comprehensive investigation of conflicting literature interpretations of the two outermost photoelectron bands, complemented by high-level calculations characterizing the three O lone-pair-based orbital ionizations expected in this region. Franck-Condon simulations allow the regular vibrational progressions observed at the beginning of the first and second bands to be assigned as predominantly modes v5 and v6 of the D0 and D2 cation states, respectively. Irregular structuring observed midband in both bands is attributed to avoided crossings between the adiabatic D0/D1 and D1/D2 states as identified in potential surface cuts taken along the v5 and v6 normal mode coordinates. The associated D0/D1 and D1/D2 conical intersections were located and characterized, allowing possible vibronic coupling and its impact on the photoelectron spectra of the D0, D1, and D2 states to be discussed. This helps rationalize the apparently missing D1 ionization in this region, although some contribution by this state may be identifiable in the β-parameter spectra. Theoretical analysis of the complete valence region spectrum identifies the early breakdown of the independent electron model beyond these first two bands
Low-Side Lobes 3D Printed Slotted Waveguide Antenna Array for Millimeter-Wave Communication Systems
Get PDFIn this paper, a 3D printed slotted waveguide antenna array is proposed for millimeter-wave communication systems at 28 GHz. The design method consists of the characterization of an isolated slot and then development of the linear and planar arrays. The proposed linear and planar arrays are 3D printed and metallized using a low-cost technique. A non-uniform 3D printed waveguide-based feeding is also designed to feed the planar array for achieving low-side lobes (< -20 dB) in the E-plane. Corrugations are added to reduce the side lobes of the planar array at the edges. The proposed antenna design is validated through experimental results suggesting an operating bandwidth of 15.8% between 26.45 GHz and 31 GHz for the linear array and 14.2% between 26.4 GHz and 30.4 GHz for the planar array with corrugations. The linear and planar arrays have high gain performance greater than 12.0 dBi and 19.0 dBi, respectively, over their operating bandwidths. The proposed arrays are suitable candidates for various applications operating in the millimeter-wave frequency bands, featuring cost-effectiveness, reduced weight, high gain, and excellent overall performance in terms of radiation
Description of probiotic use in preterm infants in England and Wales 2016–2022
Get PDFObjective: To describe the use of probiotics among preterm infants in neonatal units and explore factors that influence exposure.Design: Observational study using prospectively recorded health data.Setting: England and Wales.Patients: 48 048 infants born at 28 weeks GA (median day 4, IQR 2–7), most frequently after enteral feeds (66% of exposed infants) and were usually discontinued between 32 and 36 weeks postmenstrual age (PMA) (47% at 32+0–33+6 weeks PMA, 33% at 34+0–35+6 weeks PMA). Among infants cared for in probiotic neonatal intensive care units (defined as units where 50% or more infants born <32 weeks gestation were exposed to probiotics), 23% were never given probiotics. Infants from whom probiotics were withheld had a lower gestational age, lower birth weight z score and higher illness severity score or were more mature.Conclusions: By 2022, over half of infants born at <32 weeks GA were exposed to probiotics, but almost one quarter did not receive them despite being in a probiotic unit. Our findings help inform the interpretation of observational data and the design of future studies addressing the continued uncertainty around the safety and efficacy of probiotics
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