134125 research outputs found
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Developing time-dependent fragility curves for cube-armored breakwaters: stochastic modeling and experimental quantification
No full textCube-armored breakwaters progressively deteriorate under long-term water wave action due to the instability of armor layers. However, quantifying deterioration process remains challenging due to the probabilistic characteristics of damage. This study proposes a method for establishing time-dependent fragility curves that account for stochastic deterioration in armor units through theoretical modeling and experimental quantification. First, a Markov chain model is employed to describe the stochastic deterioration of cube-armored breakwaters with the introduction of conditional transition matrices. Subsequently, comprehensive experimental quantification involving 288 two-stage wave flume tests on cube-armored breakwaters with a 1:1.5 slope was conducted to derive general fragility curves and conditional transition matrices. The time-dependent fragility curves considering breakwater deterioration are then established by integrating initial damage with the temporal progression of deterioration via a Markov chain. Application of the framework highlights differing structural vulnerabilities under distinct wave regimes, showing progressive vulnerability with deterioration and heightened sensitivity at lower damage levels. Minor discrepancies of diverse modeling approaches indicate the practical viability of a homogeneous Markovian deterioration model. The proposed framework advances probabilistic damage assessment of coastal infrastructures, offering referable insights for maintenance strategies and resilience assessment.No Full Tex
Time-limited ICU trials: A method for value-based rapid response team decision-making
No full textThe ageing demographic across high-income and middle-income countries is reshaping the epidemiology of intensive care (ICU) admissions. Contemporary critical care increasingly involves complex decisions in populations characterised by ageing, frailty, and multimorbidity.No Full Tex
Pain and the immune system
No full textAlthough classically considered from a neuro-centric vantage point, is now well known that pain involves interaction between the immune and nervous systems. Neuro-immune interactions occur all along the pain axis from the tissues to the peripheral neurons, the dorsal root ganglia, the spinal cord and supraspinal centres. Immune cells from mast cells, macrophages, T cells and B cells, to the Schwann cells of neurons, and the glia cells in the spinal cord and brain, release diverse inflammatory mediators including cytokines and chemokines. Fundamental mechanisms underlying pain enhancement by immune cells are diverse and differ between nociceptive, neuropathic and nociplastic pain conditions. The involvement of the immune system in pain provides enormous potential for interventions to address pain by targeting these mechanisms. These interventions include pharmacological and genetic treatments, as well as non-pharmacological treatments with the potential to impact systemic and CNS immune activity, such as exercise, diet and treatments targeting psychosocial and behavioural features (e.g., sleep and stress). Logically, treatment efficacy should depend on matching the treatment to the relevant neuro-immune mechanism. The aim of this review is to provide a foundation to understand the relevance of neuro-immune interactions to the development and persistence of chronic pain, and its implications for treatment. We provide an overview of the role of neuroinflammation in pain, evidence that this contributes to human pain conditions, and how this can guide matching the right treatments to the right person.No Full Tex
Micro Elastofluidics for Tuneable Droplet Merging
Full text linkDroplet microfluidics enables precise handling of discrete fluid volumes at the microscale, with broad applications in biomedicine, food and beverage, and material synthesis. Droplet merging is an essential droplet manipulation capability that allows controlled reagent delivery, sample mixing, biochemical reactions, and single-cell analysis. Among the various active and passive droplet merging techniques, micropillar-assisted merging provides better control over merged droplet size and number, yet still requires laborious flow tuning and redesign for varying merging scenarios. To overcome these limitations, we developed a flexible, stretchable microfluidic platform for tuneable droplet merging. The merging element consists of three parallel channels, separated by two micropillar arrays. Three parallel channels can be laterally stretched to tune channel dimensions and hydraulic resistances, resulting in a change in the associated pressure distribution that determines droplet merging. We first characterised droplet generation and merging in rigid devices. Next, we conducted a theoretical and numerical analysis on the effects of stretching on hydraulic resistance and pressure distribution in the merging element. Subsequently, we fabricated the stretchable microfluidic devices and tested droplet generation and merging under various device elongation strains. We found that device stretching allows for selective droplet merging of varying numbers and tuneable mixing efficiency. This approach demonstrates a new route for controlling droplet deceleration, spacing, and merging without modifying flow conditions or device redesign. This stretchable microfluidic platform introduces a reconfigurable, efficient approach for droplet merging, with potential applications in droplet-based chemical reactions, biological assays and single-cell analysis.Full Tex
Multiscale modelling with data-calibrated material parameters for microstructure evolution in Ti5553 machining
No full textPrecise prediction of microstructural evolution is essential for improving the machinability of high-strength titanium alloys. This study presents a multiscale modelling framework for Ti5553 machining by coupling FE, JMAK, and CA models. To ensure accuracy across macro–micro scales, key material parameters are calibrated using a hybrid strategy that integrates quasi-static, high strain rate, and high-temperature thermomechanical tests. TANH constitutive parameters are refined through inverse optimization based on cutting force data, while CA nucleation and dislocation parameters are identified using high-temperature SHPB tests. JMAK parameters are extracted from Gleeble-based deformation experiments. The model is validated under both orthogonal cutting and milling conditions. In orthogonal cutting, the maximum prediction error for cutting force is 3.5%, and grain size errors are within 15.8% (CA) and 8.7% (JMAK). In milling, the model captures the evolution of a work-hardened layer, with grain size predictions below 15% error. The dual-phase microstructure of Ti5553 leads to distinctive heterogeneous shear banding behaviors, which are clearly captured by the proposed multiscale model. The CA model effectively resolves grain size gradients in the subsurface, while JMAK provides a macro/meso view about average grain size distribution. This work offers a validated modelling tool for predicting machining-induced microstructure and provides guidance for process optimization.No Full Tex
Unlocking low N2O emissions from nitrate-laden wastewater in constructed wetlands: critical role of pyrrhotite substrate layer in mediating nitrate-dependent sulfide oxidation
No full textConstructed wetlands (CWs) treating nitrate-rich wastewater often face incomplete denitrification and elevated N2O emissions due to insufficient electron donors. Pyrrhotite as a CW substrate demonstrated potential for enhancing autotrophic denitrification through coupled sulfur and iron biological oxidation. However, the impact of pyrrhotite layer positioning on regulating N2O emissions and underlying mechanisms remains unclear. This study evaluated the effect of pyrrhotite layer placement (top, middle and bottom) on S/Fe-coupled denitrification and N2O release under organic carbon-free with varying nitrogen loads. Results showed that the bottom layer achieved 32.36–65.86 % complete denitrification (2.37–5.68 times higher than middle/top layers), while B-CW limited N2O emission to only 0.36 % of converted nitrate (39.60–53.60 % lower than M−CW/T-CW). Enhanced performance in B-CW correlated with higher oxidation amounts of reduced sulfur (50.51 vs. 25.27–28.97 mg/L) and ferrous iron (36.83 vs. 18.43–21.12 mg/L), with efficient utilization. Network analysis revealed increased modularity and functional clustering in the bottom layer, with Ralstonia co-occurring with key sulfur/iron-cycling bacteria (Thiobacillus, Undibacterium) to form stable denitrifying consortia. Microbial analysis revealed enrichment of nitrate-reducing bacteria, primarily Ralstonia (14.69 %) in the bottom layer, driving 66.58 % inorganic electron utilization via sulfur oxidation-coupled complete denitrification. Electron and nitrogen mass balances revealed that 81.84 % of reduced nitrate was converted to N2. Additionally, synergistic interactions among nitrate-reducing bacteria (24.19 %), sulfur-/iron-oxidizing bacteria (16.29 %/4.46 %), organic matter-degrading bacteria (23.23 %), and electroactive bacteria (8.12 %) supported the process. These findings highlight pyrrhotite layer depth as a critical regulator of N2O mitigation in CWs, providing a sustainable inorganic strategy for low-carbon and sustainable nitrogen removal.No Full Tex
Interdisciplinary collaboration in school mental health: a scoping review
No full textIntegrating mental health and wellbeing services in schools has the potential to improve students’ socio-emotional wellbeing, engagement in learning and education outcomes. This scoping review aimed to establish and synthesize the current evidence base in relation to the junction of education and mental health and wellbeing practice. A systematic search and screening of peer-reviewed and gray research literature was conducted and resulted in the identification of 56 relevant sources. Extracted data was analyzed using descriptive and qualitative synthesis via content analysis. The largely exploratory and qualitative studies examined a range of influences on interdisciplinary collaborations. Enablers and barriers were interconnected and related to interprofessional relationships, the role of teachers and administrators in collaborations, territorialism, or the perceived practice divide between education and mental health, resourcing issues and the need for role clarity, appropriate training and structures and processes which support joint working. Insights gained may inform practice, policy, and research at the evolving intersection of education and mental health and wellbeing practice.Full Tex
Turning waste into opportunity: collective effectuation and place-based circular innovation
No full textHow does collective effectuation enable communities to advance circular innovation in resource-constrained settings? We address this question through a comparative analysis of four community-led initiatives in Indonesia that transform agricultural and plastic waste into viable opportunities and livelihoods. Focusing on collective effectuation, we extend effectuation theory from individual entrepreneurs to community contexts. Our analysis explicates the mechanisms of collective effectuation by showing how the collective use of local assets towards shared goals, combined with the flexibility to adapt strategies in response to changing circumstances, is enabled through multi-stakeholder collaborations. We demonstrate how communities employ effectual strategies via a place-based approach to achieve small-scale circular innovation, highlighting how local dynamics, social ties, and governance arrangements shape entrepreneurial practice. We further extend understanding of nascent community-driven opportunities. Rather than emerging from identifiable market gaps, such opportunities are forged through the reclamation and revalorization of waste and underutilized resources. Hence, the study advances effectuation theory by introducing five mechanisms of collective effectuation that illuminate community-level entrepreneurship in emerging economies. The process model also provides practical guidance for policymakers, NGOs, and community organizations, emphasizing the importance of cultural legitimacy, coalition-building, and locally embedded governance over uniform approaches that overlook socio-cultural embeddedness.Full Tex
Removal of hemicellulose from alkaline lignin improved electrochemical performance of hard carbon for sodium-ion battery application
No full textLignin, a natural aromatic biopolymer, is often recovered as low-value by-product during the delignification process of lignocellulosic biomass for producing cellulosic pulps. In this study, crude alkaline lignin (CAL) derived from the NaOH-pretreated sugarcane bagasse was used to produce hard carbon (HC) for sodium-ion battery anode applications. The results showed that the direct use of CAL led to HC with a maximum initial Coulombic efficiency (ICE) and reversible capacity of only 60.2% and 198.5 mAh g−1, respectively. To improve the electrochemical performance, solvent extraction was applied to purify CAL. The use of purified alkaline lignin (PAL) led to HC with a maximum ICE of 76.1% and reversible capacity of 277.5 mAh g−1, which were significantly higher than CAL-derived HC. The effects of carbonization temperature (1200 °C–1400 °C) and heating rate (1 °C–8 °C min−1) were also examined. Structural analyses revealed that hemicellulose removal resulted in HC with favorable microstructural structures, including short-range graphitic layers, closed pores, and reduced defects, facilitating the storage of Na ions. Additionally, the overall yield of PAL-HC was comparable to CAL-HC. These results demonstrated that the removal of hemicellulose is a critical initial step toward improving the electrochemical performance of HC before the application of other strategies.Full Tex
Attenuation of the CpG island methylator phenotype and lack of WNT signalling activation restrains Kras mutant intestinal neoplasia
No full textBackground: Serrated neoplasia arises from serrated precursor lesions. Hyperplastic polyps commonly activate MAPK signalling, initiated by BRAF or KRAS mutation, but premalignant KRAS-mutant sessile serrated lesions are rare. Here, we model Kras- and Braf-mutant neoplasia in vivo comparing histological, transcriptomic, and epigenetic changes. Methods: Temporospatial activation of oncogenic BrafV637 or KrasG12D was induced in murine intestine. Differential expression, methylation and pathways analyses identified oncogene-specific alterations. Results: Prolonged exposure to oncogenic Braf is associated with a time-dependent accumulation of murine serrated precursors (mSP, P = 3 × 10−10), and murine serrated lesions (mSL) and invasive cancer (8 × 10−8). Kras-mutants acquired fewer mSPs (P = 0.06) and lower probability of developing mSLs (P = 0.004). Kras-mutant mSLs rarely develop aberrant WNT signalling (1/23). Transcriptomic profiles diverged, with Braf-mutant intestines showing enriched immune and inflammatory signalling. Deconvolution analysis revealed Braf-mutants had comparably higher macrophage infiltrate (P = 0.025) and upregulation of M1 macrophage gene sets (P = 0.0008). Both mutations showed accumulating DNA methylation, however, an attenuated rate in a subset of CpG sites (1306) was observed in Kras-mutant intestine. Conclusion: Kras mutation can induce serrated neoplasia, but with significantly greater latency period and lower penetrance compared to Braf. Kras-mutant neoplasms display an attenuated CIMP-like phenotype, rarely developing aberrant WNT signalling. These data refine our understanding of MAPK-induced intestinal neoplasia.Full Tex