150259 research outputs found
Sort by
Measurements of differential cross-sections of WbWb production in the dilepton channel in pp collisions at s = 13 TeV using the ATLAS detector
No full textAt the Large Hadron Collider, the WbWb final state is expected to be dominated by tt¯ production with a contribution from single-top processes. Differential cross-sections for WbWb production in the dilepton decay channel are measured at the particle level as a function of various kinematic variables. The analysis is based on data from proton-proton collisions at a centre-of-mass energy of s=13 TeV, recorded by the ATLAS detector at the Large Hadron Collider over the period from 2015 to 2018, corresponding to an integrated luminosity of 140 fb−1. Measurements are performed within the fiducial phase-space defined by the presence of two b-jets and one electron and one muon of opposite charges. The differential cross-sections are corrected for detector effects and unfolded to the particle level. Results are compared with predictions from Monte Carlo event generators at next-to-leading order in perturbative quantum chromodynamics; overall the measurements are in reasonable agreement with several generator setups, although no single prediction is able to describe all measured distributions simultaneously. These measurements provide valuable constraints on the modelling of WbWb production and the interference between doubly resonant and singly resonant WbWb production
Anode‐Free Cell Concepts: Critical Analysis and Development of Practical Batteries
No full textAnode‐free batteries (AFBs) are one of the most discussed battery concepts due to their potential advantages in terms of energy density, reduced manufacturing costs, and improved sustainability compared to conventional lithium‐ion and lithium metal batteries. However, many fundamental and practical challenges remain to be overcome in order to realize their full potential. This Perspective provides a critical overview of the latest advances in liquid and solid electrolyte AFBs, including an analysis of practical cell performance and an assessment of the advantages and challenges of this cell concept. Since the processes at the negative current collector are central to the electrochemical performance of AFBs, they are discussed in detail, with a focus on metal plating/stripping mechanisms and key degradation processes, as well as strategies for optimizing electrode properties to enable stable cycling. In addition, the associated processes in other cell components (positive electrode, electrolyte, and critical interfaces) are discussed to understand their influence on the overall performance of the cell. Finally, we identify critical gaps in understanding, data accessibility, reporting standards, and metrics that need to be addressed to guide future research and the transition from laboratory scale to practical, high‐performance devices
The Iberian exception: what was the cost of distorting electricity markets during the 2021–23 European energy crisis?
No full textEuropean wholesale power prices increased to an unprecedented level during the energy crisis in 2022. To tackle the adverse impact on consumers, Spain and Portugal implemented the Iberian Exception (IE) in June 2022, intending to decouple power prices from the rest of Europe to reduce consumer energy bills, via capping the price of gas for power plants. The ‘exception’ was allowed by the European Commission (on behalf of the EU27) because it was deemed to be likely to have a limited pan-European impact on electricity prices. We focus on the direct impact of the policy on gas demand in Spain and in Europe via examination of the bid stack in the Iberian electricity market.
We find that the IE did reduce day-ahead power prices and that there were large increases in net exports to France and Morocco resulting in significant, partially offsetting, second round power price rises in Iberia. Gas for power demand increased by 25% from Iberian power plants relative to no IE (and by 3.2% at the whole EU level). IE Induced power exports from Spain account for around one quarter of the increase in gas for power demand in Iberia. We find no evidence that the extra Iberian gas for power directly increased gas prices at the main European gas hub (TTF)
The locomotor behaviour of subfossil Malagasy sloth-lemurs (Strepsirrhini: Indriidae) and koala-lemurs (Strepsirrhini: Megaladapidae): new insights from limb trabecular bone
No full textAbstract The locomotion of Malagasy Quaternary subfossil lemurs, including palaeopropithecines (‘sloth-lemurs’) and megaladapids (‘koala-lemurs’), has been investigated on abundant postcranial remains. Proposed strategies include some that lack living primate parallels, such as sloth-like suspensory arboreality in palaeopropithecines, although the degree of suspensory behaviour in palaeopropithecines or locomotor diversity in koala-lemurs is poorly understood. Unlike the external morphology, internal bone structure in these taxa is largely unexplored. We compared the humeral and femoral trabecular architecture of sloth- and koala-lemurs with several extant mammals, studying spherical/hemispherical trabecular samples extracted from high-resolution scans. After defining locomotor categories from quantitative data, we tested links between trabecular parameters and locomotor modes through exploratory and multivariate analyses, accounting for body size and phylogeny. In extant mammals, only femoral trabecular traits, particularly the degree of anisotropy and bone volume fraction, were significantly associated with locomotion, distinguishing suspensory and bridging arboreal taxa from others. Using this model, we inferred suspensory adaptations in palaeopropithecines, especially Palaeopropithecus, confirming earlier reconstructions, but also in Megaladapis edwardsi, a striking result that would place it alongside extant orangutans as the largest mammals known to adopt such habits. This work highlights the potential of internal bone structure for reconstructing primate locomotor evolution
Optimal Dose and Safety of Intravenous Favipiravir in Hospitalized Patients With <scp>COVID</scp> ‐19: A Dose‐Escalating, Randomized Controlled Phase Ib Study
No full text
AGILE (NCT04746183) is a Phase Ib/IIa platform, evaluating candidates to treat COVID‐19. Candidate Specific Trial 6 evaluated the safety and optimal dose of a novel intravenous formulation of favipiravir in a dose‐escalating, open‐label, randomized, controlled, Bayesian adaptive Phase Ib trial. Hospitalized adults with PCR‐confirmed SARS‐CoV‐2 infection, within 14 days of symptomatic COVID‐19 were randomized 2:1 in groups of 6 (
n
= 4 favipiravir,
n
= 2 standard of care) to ascending doses of intravenous favipiravir twice daily (b.i.d.) for 7 days or standard of care. Clinical data, safety evaluations, virology and pharmacokinetic samples were collected. The primary outcome was safety. Secondary outcomes included clinical, pharmacokinetic and virological endpoints. Twenty‐four participants enrolled between September 10, 2022 and November 1, 2023 [10/24 female; median age 74 years (range 52–93)]. Favipiravir was well tolerated despite a high background rate of unrelated adverse events. No dose limiting toxicities were observed, with a model‐predicted dose limiting toxicity risk of 16.8% and probability of unacceptable toxicity of 2.7% at the highest dose level. No serious adverse events were deemed related to favipiravir but an expected association with asymptomatic, transient hyperuricemia was observed. Favipiravir exposures increased disproportionally to dose with significant accumulation in plasma, but with marked variability between participants within each cohort. This novel formulation of favipiravir was safe at sustained high doses that reached pre‐specified pharmacokinetic targets in a study group with frailty and complex health profiles. We consider doses up to 2,400 mg b.i.d. to be safe for further evaluation.
</jats:p
Conservation biology: Fossils inform the future.
No full textConservation decision-making increasingly requires data beyond those from depauperate modern ecosystems. A new study that integrates Pleistocene fossil records of lizards with modern genomic and geographic data provides a roadmap for integrating the past and present to identify specific conservation strategies
Temperature Control in Acute Brain Injury
No full textTemperature is a key determinant of cerebral vulnerability after acute brain injury and one
of the physiological variables that can be continuously monitored and actively controlled
in the intensive care unit. While early enthusiasm for therapeutic hypothermia was driven
by strong experimental rationale, subsequent trials have clarified that temperature-related
physiological effects have not translated into improved clinical outcomes across acute brain
injury phenotypes.
In patients with traumatic brain injury, acute vascular brain injury, and post–cardiac
arrest encephalopathy, fever and temperature variability are consistently associated with
worse neurological outcomes. In traumatic brain injury, hypothermia reliably reduces
intracranial pressure but has not shown outcome benefit as an early prophylactic treatment
and is now reserved for refractory intracranial hypertension. In acute vascular brain injury,
neutral trial results and practical limitations, including poor tolerance of cooling in awake
patients and delays in achieving stable target temperatures, have shifted practice away from
therapeutic hypothermia toward early detection and treatment of fever. In post–cardiac
arrest care, contemporary trials and guidelines emphasise maintenance of a constant target
temperature within a broad range, underscoring that benefit derives from active
temperature control rather than mandatory hypothermia.
Temperature control should be viewed as deliberate physiological management
aimed at preventing temperature-related harm while recognising that patient care should
be individualised to accommodate specific disease mechanisms, patient heterogeneity and
feasibility in routine clinical practice. Contemporary practice in intensive care settings
prioritises controlled normothermia, selective hypothermia for defined indications (i.e.
refractory intracranial hypertension), continuous monitoring, and protocolised
implementation integrated into multimodal neurocritical care. This review synthesises
physiology, clinical evidence, and guideline evolution to frame temperature control as a
precision-based intervention within the intensive care management of acute brain injury
A systematic evaluation of uncertainty quantification techniques in deep learning: a case study in photoplethysmography signal analysis
No full textIn principle, deep learning models trained on medical time-series, including wearable photoplethysmography sensor data, can provide a means to continuously monitor physiological parameters outside of clinical settings. However, there is considerable risk of poor performance when deployed in practical measurement scenarios leading to negative patient outcomes. Reliable uncertainties accompanying predictions can provide guidance to clinicians in their interpretation of the trustworthiness of model outputs. It is therefore of interest to compare the effectiveness of different approaches. Here we implement an unprecedented set of eight uncertainty quantification (UQ) techniques to models trained on two clinically relevant prediction tasks: atrial fibrillation (AF) detection (classification), and two variants of blood pressure regression. We formulate a comprehensive evaluation procedure to enable a rigorous comparison of these approaches. We observe a complex picture of uncertainty reliability across the different techniques, where the most optimal for a given task depends on the chosen expression of uncertainty, evaluation metric, and scale of reliability assessed. We find that assessing local calibration and adaptivity provides practically relevant insights about model behaviour that otherwise cannot be acquired using more commonly implemented global reliability metrics. We emphasise that criteria for evaluating UQ techniques should cater to the model’s practical use case, where the use of a small number of measurements per patient places a premium on achieving small-scale reliability for the chosen expression of uncertainty, while preserving as much predictive performance as possible
Influence of Liquid on Crystallite Size Evolution During Ball Milling
No full textLiquid-assisted grinding (LAG) is a commonly used mechanochemical procedure, especially for polymorphic conversions. However, it is not understood what effect liquid additives actually have in driving mechanochemical polymorphic conversions, precluding our ability to control solid form transformations under mechanochemical conditions. We here present a time-resolved in situ (TRIS) synchrotron powder X-ray diffraction (PXRD) monitoring strategy that can track, with few-nanometer resolution, the evolution of crystallite size under liquid-assisted ball milling conditions. We apply this method to investigate the influence of liquid additives on the polymorphic conversion of the 1:1 cocrystal of theophylline and benzamide, with particular focus on the role that crystallite size plays in driving ball milling-induced polymorphic transformations. We found that the crystallite sizes achieved by ball milling are highly sensitive to the amount of liquid added to the reaction mixture. Liquid additives generally lead to larger crystallite sizes as compared with the neat grinding (NG) protocol, with our findings indicating that crystallite size reduction is not the main factor that causes polymorph conversion under liquid-assisted grinding conditions. The data presented clearly suggest the presence of an induction period before phase transformation begins with a minimum value in the crystallite size of the starting polymorph, marking the end of that induction period