bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model-Based Analysis of a Combined Heat and Power System Featuring a Hydrogen-Fired Gas Turbine With On-Site Hydrogen Production and Storage
Authors: Bexten Thomas , Wirsum Manfred , Roscher Björn , Schelenz Ralf , Jacobs Georg 
Published: January 2021

Abstract
Hydrogen-fired gas turbines can play an important role in carbon-neutral energy and industry sectors. However, the required demand-oriented supply of CO2-neutral hydrogen is technically and economically challenging. These challenges arise due to interdependencies between the volatility of renewable power generation, available hydrogen production capacities, available hydrogen storage capacities and the operational demands to be met by gas turbines. The present study aims to quantify these interdependencies by conducting a model-based analysis of an exemplary CHP system featuring a hydrogen-fired industrial gas turbine with on-site hydrogen production via electrolysis and on-site hydrogen storage. To identify the sought-after interdependencies, simulations featuring various system parameterizations are analyzed. If only local power surpluses are utilized for the operation of electrolyzers, the results show a nonlinear impact of both the hydrogen production capacity and the hydrogen storage capacity on the hydrogen-based gas turbine operation. Furthermore, the results indicate that an exclusive utilization of local power surpluses leads to limited periods of hydrogen-based gas turbine operation and low utilization rates of the hydrogen production and storage capacities. If additional power for the operation of electrolyzers is supplied by the grid, increased utilization rates and prolonged periods of hydrogen-based gas turbine operation can be achieved. However, to realize an overall reduction of CO2 emissions, this mode of operation requires the supply of large quantities of renewable power by the grid. The results of an additional economic assessment reveal that both investigated operational modes are not economically viable within the considered economic framework.
A Joint Experimental and Large Eddy Simulation Characterization of the Liquid Fuel Spray in a Swirl Injector
Authors: Vignat Guillaume , Rajendram Soundararajan Preethi , Durox Daniel , Vié Aymeric , Renaud Antoine , Candel Sébastien 
Published: January 2021

Abstract
The quality of liquid fuel spray injection determines to a large extent the performance of aero-engine combustors. This investigation focuses on the detailed characterization of the liquid fuel spray in a test rig targeted at aero-engine applications. The liquid fuel is injected as a hollow cone by a simplex atomizer and the injector comprises a radial swirler. Two features of the droplet distribution are less commonly found. First, the distributions of droplet diameters exhibit nonaxisymmetric patterns, which are investigated for three types of swirlers. Second, it is found that the size-conditioned velocity distributions feature a single wide peak for small droplets and become bimodal for the largest droplets, with a first peak at low velocities, and a second one at higher velocities. Experiments are complemented with large eddy simulations and Lagrangian particle tracking. The spray interacts with the lateral injector surface and requires a droplet–wall interaction model for the liquid film. Simulations do not retrieve the lack of rotational symmetry that is found experimentally indicating that this feature is not linked to the nature of the flow. This is also consistent with further experiments with a different atomizer confirming that this is due to imperfections in the atomizer geometry. Another result is that certain swirler designs are more robust to atomizer imperfections. Simulations accounting for the liquid film yield a bimodal distribution for the droplets' axial velocity distribution which is not obtained without this model, indicating that it is important to represent the droplet–wall interaction.
Novel Cyclo-Nonstationary Indicators for Monitoring of Rotating Machinery Operating Under Speed and Load Varying Conditions
Authors: Mauricio Alexandre , Helm Dustin , Timusk Markus , Antoni Jerome , Gryllias Konstantinos 
Published: January 2021

Abstract
Condition monitoring arises as a valuable industrial process in order to assess the health of rotating machinery, providing early and accurate warning of potential failures and allowing for the planning and effective realization of preventative maintenance actions. Nowadays, machinery (gas turbines, wind turbines, etc.) manufacturers adopt new business models, providing not only the equipment itself but also additionally taking on responsibilities of condition monitoring, by embedding sensors and health monitoring systems within each unit and prompting maintenance actions when necessary. Among others, rolling element bearings are one of the most critical components in rotating machinery. In complex machines, the failure indications of an early bearing damage are weak compared to other sources of excitations (e.g., gears, shafts, rotors). Vibration analysis is most widely used and various methods have been proposed, including analysis in the time and frequency domain. In a number of applications, changes in the operating conditions (speed/load) influence the vibration sources and change the frequency and amplitude characteristics of the vibroacoustic signature, making them nonstationary. Under changing environments, where speed and load vary, the assumption of quasi-stationary is not appropriate and as a result, a number of time-frequency and time-order representations have been introduced, such as the Short Time Fourier Transform and the Wavelets. Recently, an emerging interest has been focused on modeling rotating machinery signals as cyclostationary, which is a particular class of nonstationary stochastic processes. The classical cyclostationary tools, such as the Cyclic Spectral Correlation Density (CSCD) and the Cyclic Modulation Spectrum (CMS), can be used in order to extract interesting information about the cyclic behavior of cyclostationary signals, only under the assumption that the speed of machinery is constant or nearly constant. Global diagnostic indicators have been proposed as a measure of cyclostationarity under steady operating conditions. In order to overcome this limitation, a generalization of both SCD and CMS functions has been proposed displaying cyclic Order versus Frequency as well as diagnostic indicators of cyclo-nonstationarity in order to cover the speed-varying operating conditions. The scope of this paper is to propose a novel approach for the analysis of cyclo-nonstationary signals based on the generalization of indicators of cyclo-nonstationarity in order to cover the simultaneous and independently varying speed and load operating conditions. The effectiveness of the approach is evaluated on simulated and real signals captured on a dedicated test rig.
Laser Sharpening of Carbon Fiber Microelectrode Arrays for Brain Recording
Authors: Dong Tianshu , Chen Lei , Shih Albert 
Published: January 2021

Abstract
Microwire microelectrode arrays (MEAs) are implanted in the brain for recording neuron activities to study the brain function. Among various microwire materials, carbon fiber stands out due to its small diameter (5–10 μm), relatively high Young's modulus, and low electrical resistance. Microwire tips in MEAs are often sharpened to reduce the insertion force and prevent the thin microwires from buckling. Currently, carbon fiber MEAs are sharpened by either torch burning, which limits the positions of wire tips to a water bath surface plane, or electrical discharge machining, which is difficult to implement to the nonelectrically conductive carbon fiber with parylene-C insulation. A laser-based carbon fiber sharpening method proposed in this study enables the fabrication of carbon fiber MEAs with sharp tips and custom lengths. Experiments were conducted to study effects of laser input voltage and transverse speed on carbon fiber tip geometry. Results of the tip sharpness and stripped length of the insulation as well as the electrochemical impedance spectroscopy measurement at 1 kHz were evaluated and analyzed. The laser input voltage and traverse speed have demonstrated to be critical for the sharp tip, short stripped length, and low electrical impedance of the carbon fiber electrode for brain recording MEAs. A carbon fiber MEA with custom electrode lengths was fabricated to validate the laser-based approach.
Association Between Resistance to Cerebrospinal Fluid Flow Near the Foramen Magnum and Cough-Associated Headache in Adult Chiari Malformation Type I
Authors: Ibrahimy Alaaddin , Huang Chi-Wen Christina , Bezuidenhout Abraham F. , Allen Philip A. , Bhadelia Rafeeque A. , Loth Francis 
Published: January 2021

Abstract
Cough-associated headaches (CAHs) are thought to be distinctive for Chiari malformation type I (CMI) patients and have been shown to be related to the motion of cerebrospinal fluid (CSF) near the foramen magnum (FM). We used computational fluid dynamics (CFD) to compute patient-specific resistance to CSF motion in the spinal canal for CMI patients to determine its accuracy in predicting CAH. Fifty-one symptomatic CMI patients with cerebellar tonsillar position (CTP) ≥ 5 mm were included in this study. The patients were divided into two groups based on their symptoms (CAH and non-CAH) by review of the neurosurgical records. CFD was utilized to simulate CSF motion, and the integrated longitudinal impedance (ILI) was calculated for all patients. A receiver operating characteristic (ROC) curve was evaluated for its accuracy in predicting CAH. The ILI for CMI patients with CAH (776 dyn/cm5, 288—1444 dyn/cm5; median, interquartile range) was significantly larger compared to non-CAH (285 dyn/cm5, 187–450 dyn/cm5; p = 0.001). The ILI was more accurate in predicting CAH in CMI patients than the CTP when the comparison was made using the area under the ROC curve (AUC) (0.77 and 0.70, for ILI and CTP, respectively). ILI ≥ 750 dyn/cm5 had a sensitivity of 50% and a specificity of 95% in predicting CAH. ILI is a parameter that is used to assess CSF blockage in the spinal canal and can predict patients with and without CAH with greater accuracy than CTP.
Do gastroenterologists have medical inertia towards coeliac disease? A UK multicentre secondary care study
Authors: Taylor Matthew A , Blanshard Rebecca J , Naylor Gregory , Penny Hugo A , Mooney Peter D , Sanders David S 
Published: January 2021

ObjectiveThis study aimed to assess if there is secondary care medical inertia towards coeliac disease (CD).DesignGroup (1): Time from primary care presentation to diagnostic endoscopy was quantified in 151 adult patients with a positive endomysial antibody test and compared with 92 adult patients with histologically proven inflammatory bowel disease (IBD). Group (2): Across four hospitals, duodenal biopsy reports for suspected CD were reviewed (n=1423). Group (3): Clinical complexity was compared between known CD (n=102) and IBD (n=99) patients at their respective follow-up clinic appointments. Group (4): 50 gastroenterologists were questioned about their perspective on CD and IBD.ResultsGroup (1): Suspected coeliac patients waited significantly longer for diagnostic endoscopy following referral (48.5 (28–89) days) than suspected patients with IBD (34.5 (18–70) days; p=0.003). Group (2): 1423 patients underwent diagnostic endoscopy for possible CD, with only 40.0% meeting guidelines to take four biopsies. Increased diagnosis of CD occurred if guidelines were followed (10.1% vs 4.6% p<0.0001). 12.4% of newly diagnosed CD patients had at least one non-diagnostic gastroscopy in the 5 years prior to diagnosis. Group (4): 32.0% of gastroenterologists failed to identify that CD has greater prevalence in adults than IBD. Moreover, 36.0% of gastroenterologists felt that doctors were not required for the management of CD.ConclusionProlonged waiting times for endoscopy and inadequacies in biopsy technique were demonstrated suggesting medical inertia towards CD. However, this has to be balanced against rationalising care accordingly. A Coeliac UK National Patient Charter may standardise care across the UK.
Artificial intelligence-based prediction of transfusion in the intensive care unit in patients with gastrointestinal bleeding
Authors: Levi Riccardo , Carli Francesco , Arévalo Aldo Robles , Altinel Yuksel , Stein Daniel J , Naldini Matteo Maria , Grassi Federica , Zanoni Andrea , Finkelstein Stan , Vieira Susana M , Sousa João , Barbieri Riccardo , Celi Leo Anthony 
Published: January 2021

ObjectiveGastrointestinal (GI) bleeding commonly requires intensive care unit (ICU) in cases of potentialhaemodynamiccompromise or likely urgent intervention. However, manypatientsadmitted to the ICU stop bleeding and do not require further intervention, including blood transfusion. The present work proposes an artificial intelligence (AI) solution for the prediction of rebleeding in patients with GI bleeding admitted to ICU.MethodsA machine learning algorithm was trained and tested using two publicly available ICU databases, the Medical Information Mart for Intensive Care V.1.4 database and eICU Collaborative Research Database using freedom from transfusion as a proxy for patients who potentially did not require ICU-level care. Multiple initial observation time frames were explored using readily available data including labs, demographics and clinical parameters for a total of 20 covariates.ResultsThe optimal model used a 5-hour observation period to achieve an area under the curve of the receiving operating curve (ROC-AUC) of greater than 0.80. The model was robust when tested against both ICU databases with a similar ROC-AUC for all.ConclusionsThe potential disruptive impact of AI in healthcare innovation is acknowledge, but awareness of AI-related risk on healthcare applications and current limitations should be considered before implementation and deployment. The proposed algorithm is not meant to replace but to inform clinical decision making. Prospective clinical trial validation as a triage tool is warranted.
Study protocol for a multicentre, 2×2 factorial, randomised, controlled trial evaluating the interest of intravenous iron and tranexamic acid to reduce blood transfusion in hip fracture patients (the HiFIT study)
Authors: Lasocki Sigismond , Loupec Thibault , Parot-Schinkel Elsa , Vielle Bruno , Danguy des Déserts Marc , Roquilly Antoine , Lahlou-Casulli Maria , Collange Vincent , Desebbe Olivier , Duchalais Alexis , Drugeon Bertrand , Bouzat Pierre , Garrigue Delphine , Mounet Benjamin , Hamard Franck , David Jean-Stéphane , Leger Maxime , Rineau Emmanuel 
Published: January 2021

IntroductionBlood transfusion and anaemia are frequent and are associated with poor outcomes in patients with hip fracture (HF). We hypothesised that preoperative intravenous iron and tranexamic acid (TXA) may reduce the transfusion rate in these patients.Methods and analysisThe HiFIT study is a multicentre, 2×2 factorial, randomised, double-blinded, controlled trial evaluating the effect of iron isomaltoside (IIM) (20 mg/kg) vs placebo and of TXA (intravenously at inclusion and topically during surgery) versus placebo on transfusion rate during hospitalisation, in patients undergoing emergency surgery for HF and having a preoperative haemoglobin between 95 and 130 g/L. 780 patients are expected. The primary endpoint is the proportion of patients receiving an allogenic blood transfusion of packed red blood cells from the day of surgery until hospital discharge (or until D30 if patient is still hospitalised). Enrolment started on March 2017 in 11 French hospitals. The study was stopped between July 2017 and August 2018 (because of investigation of serious AEs with IIM in Spain) and slowed down since March 2020 (COVID-19 crisis). The expected date of final follow-up is May 2022. Analyses of the intent-to-treat and per-protocol populations are planned.Ethics and disseminationThe HiFIT trial protocol has been approved by the Ethics Committee of Comité de Protection des Personnes Ouest II and the French authorities (ANSM). It will be carried out according to the principles of the Declaration of Helsinki and the Good Clinical Practice guidelines. The results will be disseminated through presentation at scientific conferences and publication in peer-reviewed journals. The HiFIT trial will be the largest study evaluating iron and TXA in patients with HF.Trial registration numberclinicalTrials.gov identifier:NCT02972294; EudraCT Number 2016-003087-40.
Experiences of pregnant mothers using a social media based antenatal support service during the COVID-19 lockdown in the UK: findings from a user survey
Authors: Chatwin John , Butler Danielle , Jones Jude , James Laura , Choucri Lesley , McCarthy Rose 
Published: January 2021

ObjectivesThe COVID-19 pandemic has seen unprecedented restrictions on face-to-face healthcare encounters. This has led to an increase in the use of online healthcare resources by service users. Pregnant women have always been a group particularly motivated to seek out information online. The objective of this study was to explore the experiences of mothers who were using an existing National Health Service social media based antenatal support service during the early stages of the UK COVID-19 lockdown.DesignA short online survey with four closed questions (scale response) and one open-ended free-text question was given to pregnant women who were using the online service 3 weeks after the start of the UK lockdown. Descriptive statistics are used to present the closed question data. Thematic analysis was applied to the free-text responses.Results320 women were sent the survey. 156 completed it (49% response rate). Participants provided information relating to frequency of use, information access, relative level of antenatal care and ease of contact. 105 (66%) participants completed the open-ended free-text question. Key themes to emerge related to: (1) information provision and verification; (2) managing and reducing feelings of isolation; (3) service specific issues, including crisis adaptations; and (4) impact on routine care.ConclusionsThe study suggests that that pregnant mothers found a social media based approach well positioned to provide antenatal care and support during the COVID-19 pandemic.
Monitoring of metabolic adverse events of second-generation antipsychotics in a naive paediatric population followed in mental health outpatient and inpatient clinical settings: MEMAS prospective study protocol
Authors: Menard Marie-Line , Ilies Drigissa , Abadie Pascale , Jean-Baptiste Thaïna , Choquette Rachel , Huet Anne-Sophie , Ben Amor Leila 
Published: January 2021

IntroductionSecond-generation antipsychotics (SGAs) are widely used in the paediatric population. It is currently established that SGAs may induce metabolic adverse events (AEs) such as weight gain, perturbation of blood lipids or glucose with risk of potential cardiovascular morbidity and mortality. The Canadian Alliance for Monitoring Effectiveness and Safety of Antipsychotics in children (CAMESA) has published recommendations for monitoring the metabolic AEs of SGAs. Factors that may be associated with the onset of SGA’s metabolic AEs and long-term consequences are less studied in the literature. The objectives of our research are to evaluate some factors that can influence the development of the SGA’s metabolic AEs and to study clinical adherence to CAMESA guidelines.Methods and analysisThe Monitoring des Effets Métaboliques des Antipsychotiques de Seconde Génération study is a multicenter, prospective, longitudinal observational study with repeated measures of metabolic monitoring over 24 months. Two recruiting centres have been selected for patients under 18 years of age, previously naive of antipsychotics, starting an SGA or who have started an SGA for less than 4 weeks regardless of the diagnosis that motivated the prescription. Assessments are performed for anthropometric measures, blood pressure, blood tests at baseline and 1, 2, 3, 6, 9, 12 and 24 months of follow-up.Ethics and disseminationThe study protocol was approved by the CHU Sainte-Justine’s Research Ethics Board (MP-21-2016-1201) in 2016 and obtained institutional suitability for the ‘Centre Intégré Universitaire de Santé et de Services Sociaux du Nord-de-l’Île-de-Montréal’ Research Center in May 2018. For all participants, written consent will be obtained from parents/caregivers as well as the participant’s assent in order to enable their participation in this research project. The results of this research will be published.Trial registration numberClinicalTrials.gov (numberNCT04395326).
Impact of air pollution on renal outcomes: a systematic review and meta-analysis protocol
Authors: Hamroun Aghilès , Camier Aurore , Bigna Jean Joel , Glowacki François 
Published: January 2021

IntroductionChronic kidney disease is a serious and a frequent disease associated with a high risk of morbi-mortality. Although several risk factors have already been well addressed, mostly diabetes and hypertension, many remain underappreciated, such as chronic exposure to air pollution.Methods and analysisWe will search EMBASE, PubMed, Web of Science, Cochrane Library and CINAHL database, from inception to 31 March 2020, for relevant records using a combination of keywords related to the type of exposure (ozone, carbon monoxide, nitrogen oxides and dioxide, sulfur dioxide, PM2.5, PMcoarseand PM10) and to the type of outcome (chronic kidney disease, end-stage renal/kidney disease, kidney failure, proteinuria/albuminuria, renal function, renal transplant, kidney graft, kidney transplant failure, nephrotic syndrome and kidney cancer). The review will be reported according to the guidelines of the Meta-analysis Of Observational Studies in Epidemiology. Two independent reviewers will select studies without design or language restrictions, using original data and investigating the association between exposure to one or more of the prespecified air pollutants and subsequent risk of renal outcomes. Using random-effects meta-analyses, we will present pooled summary statistics (HR, OR or beta-coefficients with their respective 95% CI) associated with a standardised increase in each pollutant level. The results will be presented by air pollutant and outcome. Heterogeneity will be assessed using the χ2test on Cochran’s Q statistic and quantified by calculating I2. The Egger’s test and visual inspection of funnel plots will be used to assess publication bias.Ethics and disseminationSince primary data are not collected in this study, ethical approval is not required. This review is expected to provide relevant data on the associations between various air pollutants’ exposure and renal outcomes. The final report will be published in an international peer-reviewed journal.PROSPERO registration numberCRD42020187956.