134125 research outputs found
Sort by
Palatal Vault Depth Affects the Accuracy of the Intaglio Surface of Complete Maxillary Denture Bases Manufactured Through Additive Manufacturing
Full text linkBackground/Objectives: The purpose of this in vitro study is to evaluate the effect varying palatal vault depths have on the accuracy of complete maxillary denture bases fabricated using additive manufacturing technology. Methods: One hundred complete maxillary denture bases were manufactured on two different digital light processing (DLP) dental 3D printers at five different palatal depths. After manufacturing, the denture bases were post-cured, scanned, and then analyzed in metrology software. Statistically significant differences were determined using two-way ANOVA tests for normally distributed data and the Kruskal–Wallis test for non-normally distributed data. Color deviation maps were used to give clinical relevance to the results. Results: Significant differences were found for both printers among some groups for the different palatal depths. In relation to the negative mean deviation, the data revealed that the NextDent printers were the least accurate (0.047 ± 0.004) in the group with the deepest palate. The positive mean deviation revealed the most deviation (0.077 ± 0.009) in the group with the deepest palate, which was also mirrored in the Asiga printer (0.050 ± 0.002). The color deviation maps revealed areas of positive and negative average deviation in all groups. The effect of the printer model (p = 0.007) and palatal depth (p = 0.04) on negative average deviation was significant. The effect of the interaction of printer and palatal depth was also significant (p = 0.001). Conclusion: Deeper palatal vaults are associated with higher deviation in DLP 3D-printed complete maxillary denture bases manufactured through additive manufacturing.Full Tex
A chlorinated hexaazatrinaphthylene cathode enabling stable sodium-ion batteries across a wide temperature range
No full textSodium-ion batteries (SIBs) are emerging as a resource-secure and cost-effective alternative to lithium-ion technologies, owing to the near-limitless abundance of sodium reserves in seawater and terrestrial salt deposits. However, the commercial viability of SIBs remains hindered by the lack of cathode materials that combine high capacity with long-term cycling stability. Herein, we report the rational design and synthesis of a novel chlorine-substituted hexaazatrinaphthylene (HATN-3Cl), exhibiting a rigid, coplanar π-conjugated framework with six redox-active nitrogen sites. When paired with metallic sodium, HATN-3Cl delivers a reversible discharge capacity of 159 mAh g−1 after 500 cycles at a current density of 0.05 A g−1, demonstrating excellent cycling stability and promising application potential. Remarkably, a capacity of 119 mAh g−1 is retained after 1000 cycles at 1 A g−1 with an average Coulombic efficiency (CE) of 99.6 %. Galvanostatic intermittent titration technique (GITT) reveals Na+ diffusion coefficients ranging from 10−8 to 10−10 cm2 s−1, attesting to rapid ion transport with minimal activation barriers. Density functional theory (DFT) calculations, corroborated by in-situ Fourier transform infrared spectrometer (FT-IR) and ex-situ X-ray photoelectron spectroscopy (XPS), confirm a highly reversible six-electron redox mechanism proceeding via two-stage Na+ ions insertion at the nitrogen sites. Moreover, the HATN-3Cl electrode sustains its capacity retention and structural integrity across a wide temperature window from −30 °C to 60 °C, satisfying the operational demands of grid-storage energy storage under extreme climates. This study therefore delivers a scalable, purely organic cathode that bridges the performance gap of SIBs and charts a sustainable pathway toward terawatt-hour-scale energy storage.No Full Tex
The influence of near-peer teaching on final year nursing students' self-efficacy in clinical teaching: A mixed methods quasi-experimental study
Full text linkBackground: Registered nurses have a professional responsibility to teach other nurses, health professionals and students; however, some newly qualified nurses lack confidence and preparedness for clinical teaching. Near-peer teaching, whereby senior students teach junior students from the same program, has been found to enhance medical students' knowledge and skills (including teaching), yet little is known about its influence on nursing students' clinical teaching self-efficacy, an important predictor of future teaching engagement. Aim: To determine if and how participation in near-peer teaching during clinical placement on senior (final Year 3) influenced nursing students' self-efficacy in clinical teaching. Design: A mixed methods explanatory sequential design was used, involving a quasi-experiment and interviews. Methods: Senior nursing students participated in either a near-peer teaching or traditional facilitator-led model during a two-week clinical placement in an acute care hospital. At the start and end of placement, participants completed a modified clinical teaching self-efficacy scale. Near-peer teaching participants were then interviewed. Survey responses were statistically analysed within and between participant groups. Interviews transcripts were thematically analysed with hybrid coding and integrated with quantitative results to corroborate, explain and expand results. Results: Near-peer teaching participants' (n = 33) clinical teaching self-efficacy significantly increased (p < .001) during placement; control participants had no change (n = 38; p = .73). All interviewed participants (n = 12) reported increased clinical teaching confidence. Having prior peer teaching experience, repeatedly engaging in teaching, observing others teach and receiving feedback and encouragement during placement strengthened participants' clinical teaching self-efficacy and willingness to teach in the future. Conclusions: Near-peer teaching during clinical placement strengthens final year nursing students' clinical teaching self-efficacy and supports practice-readiness – findings not previously reported in the literature. University faculty from health disciplines should consider near-peer teaching integration to prepare students for essential teaching roles in healthcare contexts.Full Tex
Noise-Robust and Sector-Aware Representation Learning for Natural Gas Demand Forecasting
No full textWith natural gas becoming a key component of energy systems, precise demand forecasting is crucial for supporting efficient planning and resource management. However, existing methods face two key challenges: substantial noise in industrial datasets and heterogeneous consumption patterns across sectors. Data noise caused by sensor errors, irregular reporting, and logging inconsistencies obscures underlying consumption trends. Simultaneously, sector-specific variations in demand make it challenging to develop a unified forecasting model capable of capturing diverse consumption behaviors. To address these challenges, we propose a novel data forecasting framework that integrates contrastive learning with targeted noise filtering to enhance data representation and prediction robustness. The noise filtering module incorporates a denoising task that enables the model to learn to suppress noise and improve representation reliability. Meanwhile, the contrastive learning mechanism leverages sector-specific information to capture both shared patterns and sectoral usage behaviors. We further introduce a false negative removal strategy to refine sample selection, reducing representation bias and enhancing generalization. Our approach is validated on a large-scale dataset from the ENN Group, covering over 10,000 industrial, commercial, and welfare-related customers across multiple regions. Experimental results demonstrate that our model consistently outperforms a range of state-of-the-art forecasting baselines across both short- and long-term horizons, achieving notably better accuracy and robustness in real-world scenarios. This work demonstrates the potential of noise-robust and sector-aware representation learning for advancing natural gas demand forecasting in real-world applications.Full Tex
Leadership in layers: An integrative review on skip-level leadership and an agenda for future research
No full textIn this integrative review, we spotlight the skip-level leader − an often-overlooked yet highly influential figure in organizations. Although empirical interest in skip-level leaders has grown across disciplines, research to date remains dispersed, inconsistent in conceptualization, and disconnected from the broader organizational literature. To provide a clear and comprehensive understanding of skip-level leaders, we organize our review around four key emergent functions, skip level leaders’: 1) direct relationship with employee outcomes, 2) indirect relationship with employee outcomes via direct supervisors, 3) interactive relationship via skip-level leader attributes, and 4) the relationship of employee attributes with skip-level leader attributes (i.e., upward relationship). We present these functions both graphically and thematically as a roadmap for future research. Importantly, existing scholarship on skip-level leadership research is dominated by non-causal studies, limiting the field’s ability to draw robust causal inferences. We critically evaluate the methodological rigor of this literature, and propose remedies to strengthen future scholarship. By systematically reviewing and synthesizing prior work, we bring greater visibility to skip-level leaders as key actors in leadership science and aim to stimulate deeper inquiry into the diverse ways they shape organizational dynamics.No Full Tex
Harnessing the power of constitutional rights and legal frameworks to scale up public mental health implementation
No full textDespite the existence of effective public mental health interventions, global coverage remains low. Only a minority of people with mental disorders receive treatment, far fewer receive interventions to address or prevent the associated impacts of mental disorders, and there is negligible coverage of interventions to prevent mental disorders or promote mental wellbeing and resilience. This implementation failure breaches the right to health and statutory legislation in some countries and results in population-scale preventable suffering, broad societal and individual impacts, and associated economic costs. Various reasons account for public mental health implementation failure, including insufficient policy and implementation according to population needs, and insufficient knowledge, resource, political will, and legal protection regarding the right to mental health. This Health Policy highlights a further reason for implementation failure is that only 12% of constitutions covering 3·5% of the world's population explicitly recognise a constitutional right to mental health, compared with 70% of constitutions recognising a constitutional right to health or physical health. A legal framework that includes explicit constitutional protection for mental health would mean the right to mental health would supersede all other laws. This would thereby provide a basis for legislation and support legal opportunities to challenge, advocate, and improve effective public mental health implementation by different sectors. This framework and associated opportunities would support the scale-up of implementation of cross-sector policy based on the public mental health needs of a population. Such a holistic, coordinated legal approach would support scaled-up coverage of public mental health interventions to treat and prevent mental disorders and promote mental wellbeing and resilience, as well as action to address inequities and protect the rights of those with mental disorders. Improved implementation would result in broad impacts across different sectors and associated economic benefits.No Full Tex
Characterization of particulate matters and semi-volatile organic compounds emitted from indoor sources and associated human exposure
No full textIndoor environment hosts a number of sources of particulate matter pollution and semi-volatile organic compounds (SVOCs), which poses significant health risks, especially given the substantial time people spend indoors. Meanwhile, the physicochemical properties of pollutants from indoor sources can be highly diverse. Therefore, this study investigated the physicochemical characteristics of particulate matter and SVOCs emitted from three typical indoor sources (3D pens, hairdryers, and mosquito coils) and evaluated the exposure in the respiratory tract. The study revealed that mosquito coil combustion significantly increased both particle number concentration (by up to 104-fold) and mass concentration, far exceeding those from electrically heated sources; electrically powered mosquito repellents showed no significant particle emissions. Particle number concentration was predominantly distributed in the ultrafine size range (≤100 nm), while mass concentration was primarily concentrated in the 100–500 nm range. The volatility of particles from different sources varied significantly: ABS-based 3D pens (95% evaporation at 150°C) > mosquito coils (60% evaporation at 300°C) > hairdryer. Mosquito coils burning released the highest concentration of SVOCs, surpassing electrically heated sources. Particle lung deposition loads were highest for mosquito coils (8.62×103 mm²/h), followed by 3D pens with ABS filament (3.44×102 mm²/h), with ultrafine particles (≤100 nm) deposition dominated by the pulmonary region (>60%), confirming that ultrafine particulate matter from these indoor sources have a high exposure burden and a potentially high health risk. These findings underscore the need for comprehensive indoor source characterization and targeted interventions to mitigate exposure from emerging indoor particle sources.No Full Tex
Adjuvant-free biopolymer particles mimicking the Chikungunya virus surface induce protective immunity
Full text linkChikungunya virus, a mosquito-borne alphavirus, causes outbreaks of both acute and chronic musculoskeletal diseases. Despite the recent approval of a live-attenuated and virus-like particle-based vaccine, a stable, safe and efficacious vaccine that can be manufactured at low cost is lacking. To address this need, we engineered Escherichia coli to produce robust biopolymer particles (BPs) densely coated with CHIKV envelope glycoproteins E2 and E1, forming a natively folded heterodimer mimicking the virus surface (E2-BP-E1). Native E2-E1 heterodimer formation was confirmed by monoclonal antibodies binding to five neutralizing epitopes and by binding of the receptor Mxra8. The structural model of BP-tethered E2-E1 aligned with the crystal structure of mature E2-E1 complex. In vitro, E2-BP-E1 activated dendritic cells (DCs) to produce Th1 cytokines, present MHC class I/II T cell epitopes, and stimulate CD4+ and CD8+ T cell proliferation. In vivo, vaccination without adjuvant induced potent neutralizing antibodies and protective immunity, with a ∼5 log10 reduction in viremia. Histological analysis of muscle and joints confirmed reduced inflammation and pathology in vaccinated mice. E2-BP-E1 was produced using standard E. coli fermentation suggesting safe, cost-effective and scalable manufacturability offering advantages over current vaccines. Overall, we developed a stable particulate CHIKV vaccine that is safe and efficiently protects against infection without the need of an adjuvant.Full Tex
Ultrasensitive Self-Powered UV Photodetector Based on a Ti/n-4H-SiC/n++-4H-SiC Double Junction
No full textSelf-powered ultraviolet (UV) photodetectors (PDs), which directly convert UV photons into measurable electrical outputs, have broad application prospects in environmental monitoring, aerospace, and life sciences. In this work, we present an ultrasensitive energy converter PD based on a double junction (DJ) structure (Ti/n-4H-SiC Schottky junction and n-4H-SiC/n++-4H-SiC homojunction) to overcome the technological obstacles of narrow-band-gap and higher leakage currents in silicon-based PDs. The working principle is based on the UV photogeneration of electron-hole pairs, splitting, and then transportation by the built-in potentials present at the DJ interfaces. Further, the increasing power intensities (from 2 to 10 mW/cm2) enhanced the photogenerated electron-hole pairs. The accumulation of photogenerated holes on the semiconductor side of the Schottky interface further reinforced the interfacial potential, promoting more efficient charge carrier separation and transport. Thus, a larger vertical photoresponsivity of 1.597 × 10-2 A/W, a high specific detectivity of 6.90 × 1011 Jones, and an external quantum efficiency of 6.61% with shorter response times (rise time/decay time of 96/96 ms) are achieved under 300 nm UV light irradiation at 10 mW/cm2, surpassing most studies on 4H-SiC PDs. Benefiting from its simple architecture and superior photovoltaic performance, the current research demonstrates the potential of the DJ structure in micro/nano-electromechanical systems, optoelectronic sensors, and energy harvesters.No Full Tex
Impact of Transportation Network Development on Service Resilience: Insights from Beijing
No full textUrban rail transit (URT) networks can evolve substantially over time, with an increasing number and complexity of interactions between network components. In such networks, seemingly small disruptions can trigger cascading network service failures, affecting commuter comfort and experience. This study seeks to address the resilience of URT networks to service disruptions by understanding network evolution for resilience planning. Specifically, it develops the Network Resilience Assessment Framework (NRAF) to assess whether URT network structures are inherently resilient to service disruptions over time. The NRAF was applied to Beijing Subway data to evaluate the correlation between network evolution and service resilience. Key network evolution metrics, such as station line degree, clustering, and scaling factors, were analyzed to determine their impact on service resilience. The findings indicate that service resilience is correlated with the network's evolution. Both a high station line degree and clustering contribute to absorbing the impacts of service disruptions, while lower scaling factors are associated with higher annual average service resilience. The results suggest that promoting URT networking is an effective strategy for mitigating the impact of service disruptions. The study provides evidence that enhancing resilience can be achieved by fostering a more densely connected network and by decentralizing and reducing hierarchical differences at the global network level. The analysis reveals that the evolution of URT networking does not exhibit the characteristics of adverse effects diffusion, as highlighted in some previous studies. Instead, our findings provide a complementary perspective, emphasizing the role of decentralization and enhanced local connectivity in improving network resilience. These findings have immediate positive implications for Beijing URT and other evolving networks worldwide.No Full Tex