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Perovskite dielectric constants repository
No full textRaw data and derived dielectric constants (*n*, *k*, α) for neat Pb and mixed PbSn perovskite composition
Name your enemy: Lysias the metic vs the social network of power
Get PDFThe speech Against Eratosthenes was composed for a private case in which Lysias sought retribution for the killing of his brother Polemarchus at the hands of the Thirty. Eratosthenes, Lysias’ target, belonged to the moderate faction of the regime at the time of the events, but was one of the two surviving members who had remained in Athens, where he was not particularly unpopular. Lysias thus needed to portray the Thirty as a close-knit, corporative group whose members were all to be held responsible and liable for collective crimes. In this connection, a striking feature of this speech is the high number and frequency of personal names. The high density of prosoponyms contributes to painting a vivid picture of the events and their context. In particular, the large cast of villains portrays the oligarchs as an extended but well-defined social network, cornering Lysias into a position of isolation. Theramenes, their mastermind, is in turn portrayed as a well-connected but ultimately solitary villain—the mirror image of the persecuted metic
Widespread terrestrial ecosystem disruption at the onset of the Paleocene–Eocene Thermal Maximum
Get PDFThe Paleocene–Eocene Thermal Maximum (PETM, ~56 Mya) interval was marked by massive 13C-depleted carbon emissions into the ocean/atmosphere system, manifested as a negative carbon isotope excursion (CIE) in sedimentary components, and ~5 °C global average warming. Episodes of hydrological perturbations and soil-erosion have been widely documented for the PETM but their link with vegetation- and carbon cycle changes remain poorly constrained. Here, we present organic microfossil evidence showing a strong increase in fern-dominated pioneer vegetation that replaced coniferous forests on the margin of the Norwegian Sea during the first millennia of the CIE. With the present stratigraphic constraints, the “fern spike” occurred simultaneously in terrestrial settings along the North Sea, Arctic Ocean, the US east coast and in southern Australia, indicating that pioneer vegetation persisted for several millennia following a partial collapse of previously stable terrestrial ecosystems. Both the ferns and influx of microcharcoal imply recurrent physical disturbance, including soil destabilization and erosion, potentially linked to droughts, wildfires, and strong hydrological forcing resulting from extreme climate change. Together with evidence for reworked clay minerals and ancient organic matter (kerogen), these findings show that highly disturbed terrestrial ecosystems were widespread across mid- and high-latitude regions globally. Carbon cycle model simulations suggest that a substantial loss of standing and buried biomass, along with oxidation of soil organic matter, acted as important positive feedbacks during the onset of the CIE. Additionally, enhanced kerogen weathering likely contributed as another major positive feedback throughout both the onset and main phase of the CIE
Miniature Mechanical Testing to Infer Damage from Accidental and Complex Thermal Exposure for Single Crystal Superalloys
Get PDFMechanical testing featuring miniaturized specimens are resource-efficient alternative to standardized testing that can offer unparalleled insights. In this work, the established electro-thermal mechanical testing procedure was used for evaluating potential damage to microstructure given by unexpected thermal/mechanical load. Two conceptualized scenarios were considered. The first case concerns property deterioration given long-term complex exposure of temperature and stress, using specimens directly extracted from turbine blades. The second case concerns an ‘accidental’ solution treatment at near-incipient melting temperature. Quasi-static and dynamic tests were carried out to pick up potential property change against the reference condition. For the reference microstructure, low cycle fatigue was shown successful in yielding reproducible fatigue life and pick up location-dependent strain hardening response between suction vs. pressure side of a turbine blade. The property difference, given each scenario, was benchmarked accordingly and rationalized with microscopic evidence
Telephone triage in urgent unscheduled primary care in 16 European countries: a cross-national questionnaire-based expert study
Get PDFBackgroundRising demand and workforce shortages challenge European healthcare systems. Unscheduled healthcare, including out-of-hours (OOH) primary care, is often managed through telephone triage. Improving triage quality is essential to maintain accessible and sustainable unscheduled care across Europe.AimTo describe the role and organization of telephone triage in OOH primary care services that provide care for patients with urgent unscheduled health problems.DesignA cross-national questionnaire-based expert study.MethodsWe developed a web-based questionnaire that was distributed to members of a European research network on OOH primary care (EurOOHnet), aiming to have one informant per country. Questionnaire data were validated through email consultation with informants.ResultsExpert informants from 16 countries completed the survey. Most countries had general practice care, ambulance care, and emergency departments to provide urgent unscheduled care. Access routes to unscheduled care varied considerably between countries; 11 countries used telephone triage. Three triage models were identified: 1) Triage to care, 2) Advice and referral, and 3) Advice helplines. Self-advice tools, triage preparation tools, and chatbots were uncommon.ConclusionWe identified three triage models that had different roles related to access to unscheduled care. Telephone triage is used frequently to fit demand to available resources
Lead-free perovskites and derivatives for photogeneration: a roadmap to sustainable approaches for photovoltaics and photo(electro)catalysis
Get PDFThis roadmap provides a comprehensive overview of the latest advancements in lead-free perovskite materials for photovoltaic and photoelectrochemical /photocatalytic applications. It highlights the urgent need for sustainable energy solutions, emphasizing the role of lead-free perovskites in addressing challenges related to toxicity, scalability, and efficiency. The roadmap is designed to guide the reader from application-driven perspectives to fundamental materials insights, characterization techniques, fabrication strategies and overreaching sustainability considerations. The document explores key material families, including tin-, bismuth-, antimony-, and copper-based perovskites, detailing their optoelectronic properties, fabrication techniques, and application potential. Special attention is given to advanced characterization methods, green processing strategies, the integration of artificial intelligence and machine learning for material design and optimization and lifecycle impact assessments to ensure environmental sustainability. By bringing together insights from global research communities, this roadmap serves as a strategic guide for advancing lead-free perovskite technology, fostering interdisciplinary collaboration, and accelerating the transition to next-generation solar energy solutions
Screening for hypertension in the inpatient environment (SHINE): a prospective diagnostic accuracy study among adult hospital patients
Get PDFBackground: Hypertension is the leading risk factor for death globally. Undiagnosed hypertension is common, but the incidence in hospitalised patients is unclear. There are calls for universal facility-based screening for hypertension among all attending patients. The hospital inpatient setting, where blood pressure (BP) is measured routinely and repeatedly, presents an ideal opportunity. However, international hypertension guidelines do not include inpatient BP thresholds for diagnostic or treatment purposes. We investigated the performance of current UK community BP thresholds for diagnosing hypertension in the hospital setting. Objectives: Investigate the diagnostic performance of the current UK ambulatory BP diagnostic thresholds for systolic and diastolic hypertension in the hospital setting against the reference test of community-based ambulatory BP monitoring (ABPM). Design: A prospective diagnostic accuracy study. Setting: Hospital inpatients admitted to three UK centres were approached. Follow-up ABPM was delivered in the community. Participants: Eligible patients were aged between 18 and 80 years, with no prior diagnosis of, or prescription for hypertension, and whose mean cumulative daytime BP was 120 mm Hg to 179 mm Hg systolic and ≤109 mm Hg diastolic from the 24th hour of their hospital admission. Interventions: Participants received 24-hour ABPM 4–26 weeks post-discharge, as the reference test for hypertension, with UK diagnostic thresholds of an average daytime BP of ≥135 mm Hg systolic and ≥85 mm Hg diastolic applied. Participants found to be severely hypertensive at the ABPM fitting appointment were also considered reference-test positive but did not proceed with ABPM. Primary and secondary outcome measures: The diagnostic performance of a mean daytime in-hospital BP of ≥135 mm Hg systolic or ≥85 mm Hg diastolic (index test) for the prediction of hypertension diagnosed on ABPM (reference test) was assessed using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) as primary outcome measures. Additionally, we explored the accuracy of a range of alternative in-hospital systolic and diastolic BP thresholds against the same reference test. Results: 351 participants were enrolled and 206 completed the study protocol. The average age of the 206 participants was 53 years, 55% were male, and 91 (44%) had daytime community hypertension on ABPM reference testing. Of 107 participants with raised in-hospital daytime BP, 59 (55%) had daytime community hypertension. When assessing the performance of the index test for detecting daytime community hypertension, sensitivity was 65% (59/91, 54% to 75%) and specificity was 58% (67/115, 49% to 67%). The PPV was 55% (59/107, 45% to 65%) and NPV was 68% (67/99, 58% to 77%), respectively. A further 45/206 participants (23%) had night-time community hypertension when assessed using European diagnostic thresholds for nocturnal hypertension (120 mm Hg systolic or 70 mm Hg diastolic), while 25/107 of those with raised in-hospital daytime BP (23%) had night-time community hypertension. When assessing the performance of the index test for detecting either day or night-time community hypertension, sensitivity was 62% (84/135, 53% to 70%) and specificity was 68% (48/71, 55% to 78%). The PPV was 79% (84/107, 70% to 86%) and NPV was 48% (48/99, 38% to 59%). Conclusions: Undiagnosed hypertension is common in hospitalised patients, particularly those with raised in-hospital BP. While in-hospital BP alone is an imperfect predictor and should not be used as a stand-alone diagnostic test, this could serve as a trigger for further assessment of BP in the community after discharge. Trial registration number: The study protocol was registered with the ISCTRN Registry (ISRCTN80586284)
Specialist PrE-hospital rEDirection for ischaemic stroke thrombectomY (SPEEDY): study protocol for a cluster randomised controlled trial with included health economic and process evaluations
Get PDFBackground: Outcome from large vessel occlusion stroke can be significantly improved by time-critical thrombectomy but treatment is only available in regional comprehensive stroke centres (CSCs). Many patients are first admitted to a local primary stroke centre (PSC) and require transfer to a CSC, which delays treatment and decreases the chance of a good outcome. Access to thrombectomy might be improved if eligible patients could be identified in the prehospital setting and selectively redirected to a CSC. This study is evaluating a new specialist prehospital redirection pathway intended to facilitate access to thrombectomy. Methods and analysis: This study is a multicentre cluster randomised controlled trial with included health economic and process evaluations. Clusters are ambulance stations (or teams) which are work bases for ambulance practitioners. Intervention allocated ambulance practitioners use the Specialist PrE-hospital rEDirection for ischaemic stroke thrombectomY (‘SPEEDY’) pathway which comprises initiation according to specific criteria followed by contact with CSC staff who undertake a remote assessment to select patients for direct CSC admission. Control allocated ambulance practitioners continue to provide standard care which comprises admission to a local PSC and transfer to a CSC for thrombectomy if required. A co-primary outcome of thrombectomy treatment rate and time from stroke symptom onset to thrombectomy treatment will evaluate the impact of the pathway. Secondary outcomes include key aspects of emergency care including prehospital/hospital time intervals, receipt of other treatments including thrombolysis, and performance characteristics of the pathway. A broad population of all ambulance practitioner suspected and confirmed stroke patients across participating regions is being enrolled with a consent waiver. Data about SPEEDY pathway delivery are captured onto a study case record form, but all other data are obtained from routine healthcare records. Powered on a ‘primary analysis population’ (ischaemic stroke patients with pathway initiation criteria), 894 participants will detect an 8.4% difference in rate and data from 564 thrombectomy procedures will detect a 30 minute difference in time to treatment. The full study population is estimated to be approximately 80 000. Regression modelling will be used to examine primary and secondary outcomes in several analysis populations. The economic analyses will include cost-effectiveness and cost–utility analyses, and calculation of willingness to pay at a range of accepted threshold values. The process evaluation involves semi-structured interviews with professionals and patient/family members to explore views and experiences about the SPEEDY pathway. Ethics and dissemination: This study has ethical, Health Research Authority and participating NHS Trust approvals. Dissemination of study results will include presentations at national and international conferences and events, publication in peer-reviewed journals, and plain English summaries for patient/public engagement activities. Trial registration number: ISRCTN77453332
Protocol for the development of the WHO gestational weight gain charts
Get PDFIntroduction: Gestational weight gain (GWG) is an important indicator of maternal nutrition to be monitored during pregnancy. However, there is no evidence-based tool that can be used to monitor it across all geographic locations and pre-pregnancy body mass index (BMI) categories. The WHO is undertaking a project to develop GWG charts by pre-pregnancy BMI category, and to identify GWG ranges associated with the lowest risks of adverse maternal and infant outcomes. This protocol describes all the steps that will be used to accomplish the development of these GWG charts. Methods and analysis: This project will involve the analysis of individual participant data (researcher-collected or administrative). To identify eligible datasets with GWG data, a literature review will be conducted and a global call for data will be launched by the WHO. Eligible individual datasets obtained from multiple sources will be harmonised into a pooled database. The database will undergo steps of cleaning, data quality assessment and application of individual-level inclusion criteria. Heterogeneity of maternal weight and GWG will be assessed to verify the possibility of combining datasets from multiple sources and regions into a single database. Generalized Additive Models for Location, Scale and Shape will be applied for the construction of the centile curves. Diagnostic measures, internal and external validation procedures will also be performed. Ethics and dissemination: This project will include an analysis of existing study de-identified data. To be included in the pooled database, each included study should have received ethics approvals from relevant committees. Manuscripts will be submitted to open-access journals and a WHO document will be published, including the GWG charts and cut-offs for application in antenatal care