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Coupled thermo-chemo-mechanical phase field-based modelling of hydrogen-assisted cracking in girth welds
No full textA new computational framework is presented to predict the structural integrity of welds in hydrogen transmission pipelines. The framework combines: (i) a thermo-mechanical weld process model, and (ii) a coupled deformation-diffusion-fracture phase field-based model that accounts for plasticity and hydrogen trapping, considering multiple trap types, with stationary and evolving trap densities. This enables capturing, for the first time, the interplay between residual stresses, trap creation, hydrogen transport, and fracture. The computational framework is particularised and applied to the study of weld integrity in X80 pipeline steel. The focus is on girth welds, as they are more complex due to their multi-pass nature. The weld process model enables identifying the dimensions and characteristics of the three weld regions: base metal, heat-affected zone, and weld metal, and these are treated distinctively. This is followed by virtual fracture experiments, which reveal a very good agreement with laboratory studies. Then, weld pipeline integrity is assessed, estimating critical failure pressures for a wide range of scenarios. Of particular interest is to assess the structural integrity implications of welding defects present in existing natural gas pipelines under consideration for hydrogen transport: pores, lack of penetration, imperfections, lack of fusion, root contraction, and undercutting. The results obtained in hydrogen-containing environments reveal an important role of the weld microstructure and the detrimental effect of weld defects that are likely to be present in existing natural gas pipelines, as they are considered safe in gas pipeline standards
Greening Lean: overcoming barriers to integrating environmental practices in surgical Lean management projects: a scoping review
No full textBackground
Surgical practices generate the largest share of hospital waste and significantly contribute to NHS carbon emissions, highlighting the need for sustainable interventions. Lean management, which optimises efficiency and reduces waste, offers a pathway to address these concerns. However, its application in surgical settings remains fragmented and under-researched. This review explores how Lean methodologies can improve environmental outcomes in surgery and identifies systemic barriers to their implementation.
Methods
A scoping review of five databases (MEDLINE, EMBASE, SCOPUS, EBSCO, and Cochrane) and grey literature, following PRISMA-P protocols, yielded 24 academic and 13 grey literature sources from 5,011 search results. Quality assessment was performed using validated tools, and thematic analysis was applied to synthesise data and identify key challenges and opportunities.
Results
The review found limited evidence quantifying environmental benefits of Lean practices, including waste reduction, lower carbon emissions, and decreased energy consumption. 11 articles demonstrated quantifiable environmental outcomes, primarily in hand surgery and anaesthesia. Potential environmental benefits included waste reduction, nitrous oxide cylinder turnover minimisation, decreased carbon footprint, and reduction in anaesthetic use. Overall, four primary barriers were identified: lack of responsibility ownership, overly hierarchical organisational structures, collaboration challenges, and limited education and awareness.
Conclusion
As healthcare systems progress toward Net Zero targets, Lean management offers potential for simultaneous environmental and operational improvements. However, their successful application is hindered by significant barriers. Targeted educational initiatives, interdepartmental collaboration with aligned sustainable goals, and strategic support are crucial for successfully embedding environmental sustainability within surgery
Seismological characterization of northern Hikurangi margin slow slip regions associated with normal faults, seamounts and seeps
No full textAt the northern Hikurangi margin, Aotearoa New Zealand, slow slip events (SSEs) recur every 6–24 months to ∼30 km depth. Although shallow SSEs (0–10 km) are well-studied offshore, the deeper portion (10–30 km) remains poorly understood, limiting insight into SSE initiation. Here we investigate this deeper region and examine relationships between newly resolved SSEs and seismicity. Using time-dependent inversions, we resolve two small SSEs (MW 6.2 and 6.4), including one that extends from 15 to 30 km depth. Using data from a dense onshore seismograph network deployed directly above this deeper portion from December 2017 to October 2018, we construct a catalog of 3,071 high-quality earthquakes with hypocentral uncertainties ≤5 km, located with a 3-D velocity model and a new 1-D model.
Earthquake magnitudes range from -0.84 to 4.40, with a completeness magnitude of 1.7 and a b-value of 1.06. Focal mechanisms reveal numerous normal-faulting earthquakes, including some within the slab mantle. Vertically-aligned seismicity and normal-faulting earthquakes outline pathways linking the slab mantle to surface seeps of mantle-derived fluids. We infer that normal faults form due to slab bending and localized uplift of subducting seamounts, which roughen the plate interface, damage the upper plate, and promote fluid migration. Land-ward of ∼100 km from the trench, both surface seeps and normal-faulting mechanisms ceasecoinciding with the downdip limit of shallow SSEs. Together, these results suggest that the Hikurangi margin’s rough subducting plate interface exerts strong control on forearc dewatering and SSE genesis
Resection of large, broad-based pedunculated and semi-pedunculated colorectal polyps using a scissor-type endoscopic submucosal dissection knife
No full textBackground and study aims: Endoscopic resection of large, broad-based pedunculated and semi-pedunculated polyps can be technically difficult. Conventional snare resection risks immediate bleeding and piecemeal excision. We evaluated the safety and efficacy of a scissor-type endoscopic submucosal dissection (ST-ESD) knife for these lesions. Patients and methods: A single-center retrospective study was conducted of all patients who underwent ST-ESD resection of pedunculated or semi-pedunculated polyps with head size ≧ 20 mm and stalk width ≧ 10 mm. Primary outcomes were en bloc resection, intraprocedural and delayed bleeding, and perforation. Secondary outcomes were R0 resection and recurrence at first follow-up. Results: Fifty-eight resections were identified (75.6% male; median age 60 years). Median head size was 30 mm (range 20-70) with median stalk width 15 mm (range 10-50). Of them, 74.1% were in the sigmoid colon. Successful resection was achieved in 52 of 58 (89.7%); 44 (75.9%) by ST-ESD alone and eight (13.8%) snare-assisted. Six (10.3%) were abandoned; five due to visible muscle retraction and one dense stalk fibrosis. All successful resections were en bloc with R0 in 52 of 52 (100%). Minor intraprocedural bleeding occurred in nine of 58 (15.5%) and was controlled endoscopically. Forty-seven of 52 defects (90.4%) were closed prophylactically with endoscopic clips. There were no incidences of delayed bleeding or perforation. Histopathology was benign in 51 of 52 (98.1%). One adenocarcinoma was treated surgically for high-risk features. Endoscopic follow-up was available in 41 of 52 (78.8%) with no recurrence seen. Zero of six abandoned cases referred for surgery contained evidence of malignancy in the surgical specimen. Conclusions: ST-ESD is safe and effective for resection of large, broad-based pedunculated and semi-pedunculated colorectal polyps
Chronic kidney disease in hypertensive patients: the urgent need for targeted interventions in Arab countries; a systematic review
No full textBackground: Chronic kidney disease (CKD) is expected to be the 5th leading cause of years of life lost by 2040. Recently, it emerged as a significant cause of mortality and morbidity, with a high prevalence in Arab countries.
Objective: Assess CKD among hypertensive (HTN) people in Arab Countries through evaluation
of the existing literature on CKD prevalence, risk factors, screening programmes and prevention.
Study Design: A systematic review till April 2024 following PRISMA guidelines. The search strategy was registered in PROSPERO under the identification code CRD42024486068.
Methods: Databases searched were Medline, Embase, Scopus, PubMed, Cochrane Library.
Screening was done using Covidence by three independent reviewers.
Results: Out of 63 studies screened, 11 were selected for extraction. The prevalence of CKD was
higher among elderly, HTN and diabetic patients, with 38.8% having unrecognised CKD. Nearly
39% of the 400 participants in one study had undiagnosed stages 3-5 CKD. Two studies showed
that 55.8% and 75% of identified CKD patients had HTN. Physicians reported suboptimal
screening rates, with about 77% relying on the estimated glomerular filtration rate as a diagnostic
tool. Risk factors for CKD include old age, HTN, dyslipidaemia, family history of CKD, and obesity. Among physicians, 85% recommended a target blood pressure of ≤130/80, 80% advised smoking cessation, 66% prescribed anti-lipids, and 67% recommended weight loss. All studies support the fact that HTN is a risk factor for CKD.
Conclusion: CKD is an escalating problem in Arab countries, with hypertension as a major risk factor. Many patients remain undiagnosed. A region-specific CKD screening and HTN control programme is urgently needed. The findings are essential for policymakers in strengthening primary care for systematic screening of HTN and CKD
Developing a policy maturity model for prescription digital therapeutics based on expert consensus: protocol for an eDelphi study
No full textIntroduction
Prescription Digital Therapeutics (PDTx) represent an emerging frontier in healthcare, leveraging software-based solutions to treat or manage specific medical conditions. However, despite rising interest and encouraging evidence of clinical benefits, the policy landscape remains fragmented. Jurisdictions vary widely in their regulatory approaches, reimbursement pathways, and processes for clinical integration, thus creating uncertainties for developers, payers, and healthcare providers. This protocol outlines a eDelphi study to develop and validate a comprehensive policy maturity framework guiding systematic assessment of national or regional readiness for PDTx adoption.
Methods and analysis
We will conduct an eDelphi study with up to three rounds to refine and validate a PDTx policy maturity framework. Experts will be recruited purposively from six stakeholder groups (regulators, healthcare providers, payers/health economists, developers, researchers, and patient advocates), prioritising Europe while seeking variation across health system types and levels of economic development; a small number of non-European experts may be invited to broaden perspectives. An optional pilot round will gather initial feedback on the prototype framework, followed by iterative rounds to assess and revise domains, scoring criteria, and maturity thresholds. A five-point Likert scale (from “strongly disagree” to “strongly agree”) will collect quantitative data, while open-text prompts will capture qualitative insights. Consensus will be defined as ≥70% agreement and/or an interquartile range (IQR) ≤1 for critical items. Quantitative summaries and thematic analysis will guide iterative revisions of the model. This Delphi protocol aims to produce a consensus-driven framework that captures the essential elements of PDTx policy development and implementation. If validated, the framework can serve as a reference for policymakers, industry leaders, healthcare providers and researchers seeking to benchmark or advance the adoption of PDTx within health systems.
Ethics and dissemination
Ethical approval for this study was obtained from the Ethics Committee of the Faculty of Medicine of the University of Porto (reference: 320/CEFMUP/2025). Panellists will provide electronic informed consent, and data will be kept confidential. The finalized framework will be disseminated via peer-reviewed publications, conference presentations, and policy briefs targeting stakeholders involved in digital health governance
In vivo acoustoelectric neural recording in mice enabled by ultrasound-induced frequency mixing
No full textThere is a long-standing need in neuroscience for non-invasive methods that can record neural electrical activity with focal precision to diagnose brain disorders and interrogate circuit function. Here, we introduce acoustoelectric neural recording, which exploits ultrasound-induced frequency mixing to recover electrophysiological signals in vivo. Building on recent
insights into the acoustoelectric interaction, we extend earlier work in cardiac tissue to demonstrate neural signal recovery in a living mouse brain. At the ultrasound focus, neural activity is shifted to frequencies near the acoustic carrier and can be retrieved by amplitude demodulation analogous to radio transmission. We further show that acoustoelectric neural recording is robust to artefacts and permits single-trial electrophysiological measurements.
These results establish a pathway toward a real-time, portable, and non-invasive neural recording modality with the spatial precision of ultrasound
Aerosol‐cloud interactions: overcoming a barrier to projecting near‐term climate evolution and risk
No full textAerosol-cloud interactions (ACI) are a major source of uncertainty in climate science, critically affecting our ability to project near-term climate evolution and assess societal risks. These interactions influence effective radiative forcing, cloud dynamics, and precipitation patterns, yet remain insufficiently constrained due to limitations in observations, modeling, and process understanding. This uncertainty hampers robust policy advice across multiple domains—from estimating remaining carbon budgets and climate sensitivity, to anticipating regional extreme events and evaluating climate interventions such as solar radiation modification. In many cases, the influence of ACI is either underappreciated or excluded from decision-making frameworks due to its complexity and lack of quantification. This perspective outlines a path forward to overcome these barriers by leveraging emerging opportunities in satellite remote sensing, ground-based and airborne observations, high-resolution climate modeling, and machine learning. We identify key areas where rapid progress is feasible, including improved retrievals of cloud microphysical properties, better representation of natural aerosols in a warming world, and enhanced integration of observational and modeling communities. Even as anthropogenic aerosol and its impacts on clouds is reducing owing to emissions controls, addressing ACI uncertainties remains essential for refining climate projections, supporting effective mitigation and adaptation strategies, and delivering actionable science to policymakers in a rapidly changing climate system
Causes of fever in a cohort of Nepali children and the potential impact of molecular testing during a dengue fever outbreak
No full textBackground: Identifying the cause of infection is important for clinical management and public health decisions, including vaccination strategies.
In low-resource settings, causes of fever are often not identified. In this study, molecular testing panels were used to identify the causes of pediatric fever in the Kathmandu Valley, Nepal. A dengue fever outbreak facilitated the investigation of dengue diagnostics.
Methods: Children under 14 years of age were recruited to this prospective cohort study at Patan Hospital, Nepal. Clinical data and routine diagnostics were used to classify cases, including nonstructural protein 1 (NS1) antigen testing for dengue. Additional molecular diagnostics were performed on blood (12 viral, 26 bacterial and 6 fungal targets) and respiratory samples (17 viral and 3 bacterial targets).
Results: From September 1, 2021, to April 19, 2023, 565 children were enrolled, median age 3 (interquartile-range 1–7) years. Pathogens identified included dengue virus (n = 101), respiratory syncytial virus (n = 30), influ enza (n = 25), typhoidal Salmonella spp. (n = 7) and Neisseria meningitidis (n = 2). During the dengue outbreak, dengue olymerase chain reaction (PCR) and NS1 positivity rates were both high early in dengue disease, but if >3 days of symptoms, PCR positivity rates declined (10.3%) while NS1 positivity remained high into the second week of illness (80%).
Conclusions: This prospective cohort study is the most comprehensive effort to date to describe the causes of pediatric fever in the Kathmandu Valley, Nepal. The United States Centers for Disease Control and Pre vention recommends dengue PCR or NS1 antigen testing during the first 7 days of dengue fever. Our data indicate that PCR positivity declines after 3 days of symptoms, resulting in missed cases when relying solely on PCR
Spatiotemporal evolution, agglomeration heterogeneity, and poverty causing factors of poverty-stricken counties in China
No full textPoverty remains a pervasive global challenge that hinders both social and economic advancement. This research aims to investigate rural poverty in China through a
spatiotemporal analysis of impoverished counties across various time periods. The examination identifies poverty clusters and risks by utilizing the DBSCAN spatial
clustering algorithm. Additionally, it employs the multi-scale geographically weighted regression model to assess the spatial characteristics of factors and mechanisms
leading to poverty. The study identifies 663, 832, and 52 state-level impoverished counties in China in 2001, 2016 and 2021, respectively. Moreover, the counties are
categorized into six types based on the principal factors causing poverty, namely: frontier terrain constraints, infrastructure limitations, geological disaster vulnerabilities,
minority aggregation industry constraints, underdeveloped old revolutionary areas, and ecological fragility. Among these factors, topographic relief and healthcare institutions
exhibit a negative correlation with poverty, while average slope and nighttime light index display a positive correlation. Furthermore, location conditions, farmland
production potential, vegetation index, residents' deposit balance, and local government revenue demonstrate a two-way influence on GDP per capita in impoverished counties. The ecological fragility in karst areas exacerbates poverty. This study provides valuable insights for local governments to implement effective and targeted poverty alleviation strategies