bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Investigation of Unsteady Combustor Turbine Interaction for Flexible Power Generation
Authors: Lo Presti Federico , Sembritzky Marwick , Winhart Benjamin , Post Pascal , di Mare Francesca , Wiedermann Alexander , Greving Johannes , Krewinkel Robert 
Published: August 2021

AbstractWith the growing importance of regenerative power generation and especially of a hydrogen-based economy, the full potential of gas turbines of the smaller output class (&lt;10 MW) can be ideally exploited to provide peak coverage of the energy need whilst stabilizing the electric grids in the mid- and low-voltage range. Such machines can be typically started in a relatively short time (similarly to aero engines) and are capable, at the same time, of delivering dispatchable power-on-demand. A safe, stable and profitable operation under highly unsteady conditions poses renewed challenges for an optimal thermal management (especially in the HP stages) as well as control and surveillance of the machines. The understanding and hence predictability of the propagation of the temperature inhomogeneities originating at the combustor outlet remains hence a primary objective of current research, as persistent distortion patterns could be adopted at the turbine exhaust as diagnostic indications of a malfunction of the combustor, for example. In the present study, low-frequency disturbances introduced by a periodic load variation have been simulated and superimposed to the inhomogeneous, unsteady flow entering a three-stage, high-pressure industrial gas turbine fed by a can-type combustion chamber comprising six silo-burners. The effects of the unsteadiness realized at the combustor exit have been investigated by means of Detached Eddy Simulations, whereby a density-based solution approach with detailed thermodynamics has been employed. The periodic disturbances at the turbine inlet have been obtained by means of an artificially generated, unsteady field, resulting from a two-dimensional snapshot of the flow field at the combustor exit. Also, a combustor failure has been mimicked by reducing (respectively increasing) the mean temperature in some of the turbine inlet regions corresponding to the outlet of two burners. The propagation and amplitude changes of temperature fluctuations have been analyzed in the frequency domain. Tracking of the temperature fluctuations' maxima at the lowest frequencies revealed characteristic migration patterns indicating that the corresponding fluctuations persist with a non-negligible amplitude up to the last rows. A distinct footprint could also be observed at the same locations when a combustor failure was simulated, showing that, in principle, the early detection of combustor failures is indeed possible.
Strain Response and Aerodynamic Damping of a Swirl Distortion Generator Using Computational Fluid Dynamics
Authors: Hayden Andrew , Untaroiu Alexandrina 
Published: August 2021

Abstract
Boundary layer ingestion (BLI) concepts have become a prominent topic in research and development due to their increase in fuel efficiency for aircraft. Virginia Tech has developed the StreamVane™, a secondary flow distortion generator, which can be used to efficiently test BLI and its aeromechanical effects on turbomachinery. To ensure the safety of this system, the complex vanes within StreamVanes must be further analyzed structurally and aerodynamically. In this paper, the induced strain of two common vane shapes at three different operating conditions is computationally determined. Along with these predictions, the aerodynamic damping of the vanes is calculated to predict flutter conditions at the same three operating points. To achieve this, steady computational fluid dynamics (CFD) calculations are done to acquire the aerodynamic pressure loading on the vanes. Finite element analysis (FEA) is performed to obtain the strain and modal response of the StreamVane structure. The mode shapes and steady CFD are used to initialize an unsteady CFD analysis, which acquires the aerodynamic damping results of the vanes. The testcase used for this evaluation was specifically designed to overstep the structural limits of a StreamVane, and the results provide an efficient computational method to observe flutter conditions of stationary systems.
Shock Waves as Dominant Mechanism for Cavitation Damage
Authors: Osman O. O. , Abouel-Kasem A. , Ahmed S. M. 
Published: August 2021

Abstract
In this paper, the mechanism of energy transfer from cavitation bubbles to solids is demonstrated as shock waves. To identify this mechanism, cavitation bubble structures, the corresponding damaged surface, and the wear particles in vibratory erosion tests on pure aluminum Al-99.999 using high-speed and scanning electron microscope photography were observed. The eroded surface morphology was in the form of large swellings (hundreds of micrometers), which embodies the plastic flow. Results indicate that large swelling regions formed in a few seconds are caused by shock pressure waves and not by a microjet only several micrometers in size. The observed surface erosion and falling particles make it clear that the mechanism of cavitation wear is fatigue failure.
Curved orogenic belts, back-arc basins, and obduction as consequences of collision at irregular continental margins
Authors: Schliffke Nicholas , van Hunen Jeroen , Gueydan Frédéric , Magni Valentina , Allen Mark B. 
Published: August 2021

Abstract
Continental collisions commonly involve highly curved passive plate margins, leading to diachronous continental subduction during trench rollback. Such systems may feature back-arc extension and ophiolite obduction postdating initial collision. Modern examples include the Alboran and Banda arcs. Ancient systems include the Newfoundland and Norwegian Caledonides. While external forces or preexisting weaknesses are often invoked, we suggest that ophiolite obduction can equally be caused by internal stress buildup during collision. Here, we modeled collision with an irregular subducting continental margin in three-dimensional (3-D) thermo-mechanical models and used the generated stress field evolution to understand resulting geologic processes. Results show how tensional stresses are localized in the overriding plate during the diachronous onset of collision. These stresses thin the overriding plate and may open a back-arc spreading center. Collision along the entire trench follows rapidly, with inversion of this spreading center, ophiolite obduction, and compression in the overriding plate. The models show how subduction of an irregular continental margin can form a highly curved orogenic belt. With this mechanism, obduction of back-arc oceanic lithosphere naturally evolves from a given initial margin geometry during continental collision.
How B-Lynch suture and bilateral internal iliac artery ligation saved the uterus of a young patient with severe postpartum haemorrhage
Authors: Win San San , Lasimbang Helen Benedict , Lynn AUng Sai Nay , Yeap Tat Boon 
Published: August 2021

Obstetric haemorrhage is the leading cause of maternal death worldwide (27.1%) and more than 66% of its deaths were classified as postpartum haemorrhage (PPH). The most common cause of PPH is uterine atony. Obstetrician should be skillful in managing obstetric emergencies; especially pertaining to PPH. Application of the B-Lynch suture on an atonic uterus is one of the surgical options in PPH patients who wish to conserve the uterus and it has a very high success rate.We present a primigravida patient who developed massive primary PPH followed by disseminated intravascular coagulation, which was successfully managed with B-Lynch suture and bilateral internal iliac artery ligation. We described in detail regarding the management of massive PPH and application of these surgical procedures on the atonic uterus with an attempt to preserve the uterus and future fertility in this young patient.
Predictive modeling of COVID-19 case growth highlights evolving racial and ethnic risk factors in Tennessee and Georgia
Authors: Gray Jamieson D , Harris Coleman R , Wylezinski Lukasz S , Spurlock, III Charles F 
Published: August 2021

IntroductionThe SARS-CoV-2 (COVID-19) pandemic has exposed the need to understand the risk drivers that contribute to uneven morbidity and mortality in US communities. Addressing the community-specific social determinants of health (SDOH) that correlate with spread of SARS-CoV-2 provides an opportunity for targeted public health intervention to promote greater resilience to viral respiratory infections.MethodsOur work combined publicly available COVID-19 statistics with county-level SDOH information. Machine learning models were trained to predict COVID-19 case growth and understand the social, physical and environmental risk factors associated with higher rates of SARS-CoV-2 infection in Tennessee and Georgia counties. Model accuracy was assessed comparing predicted case counts to actual positive case counts in each county.ResultsThe predictive models achieved a mean R2of 0.998 in both states with accuracy above 90% for all time points examined. Using these models, we tracked the importance of SDOH data features over time to uncover the specific racial demographic characteristics strongly associated with COVID-19 incidence in Tennessee and Georgia counties. Our results point to dynamic racial trends in both states over time and varying, localized patterns of risk among counties within the same state. For example, we find that African American and Asian racial demographics present comparable, and contrasting, patterns of risk depending on locality.ConclusionThe dichotomy of demographic trends presented here emphasizes the importance of understanding the unique factors that influence COVID-19 incidence. Identifying these specific risk factors tied to COVID-19 case growth can help stakeholders target regional interventions to mitigate the burden of future outbreaks.
Probiotics for the prevention of antibiotic-associated diarrhoea: a systematic review and meta-analysis
Authors: Goodman Clare , Keating Georgia , Georgousopoulou Ekavi , Hespe Charlotte , Levett Kate 
Published: August 2021

ObjectiveTo evaluate existing evidence for the use of probiotics in preventing antibiotic-associated diarrhoea (AAD) in adults.DesignSystematic review and meta-analysis of randomised controlled trials (RCTs).Data sourcesWe performed a literature search of the electronic databases CINAHL Plus, EMBASE, MEDLINE (Ovid) and Web of Science from database inception to May 2021 as well as hand searching of trial registries and reference lists of related reviews.Study selectionTwo reviewers identified whether RCTs met the following inclusion criteria: adult population to whom antibiotics were administered; a probiotic intervention; a placebo, alternative dose, alternative probiotic strain or no treatment control; and incidence of AAD as the outcome.Data extraction and synthesisTwo reviewers independently collected data and assessed risk of bias using preconstructed data extraction forms. We used a random effects model for all analyses. Subgroup analyses were performed to evaluate species-specific and dose-specific response.ResultsForty-two studies (11,305 participants) were included in this review. The pooled analysis suggests that co-administration of probiotics with antibiotics reduces the risk of AAD in adults by 37% (risk ratio (RR)=0.63 (95% CI 0.54 to 0.73), p<0.00001). The overall quality of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria was found to be moderate. In subgroup analyses, high dose compared with low dose of the same probiotic demonstrated a positive protective effect (RR 0.54 (95% CI 0.38 to 0.76), p<0.01), and only certain species, mainly of the lactobacillus and bifidobacteria genera, were found to be effective. Studies with a low baseline AAD risk did not show any difference in risk but studies with moderate or high baseline AAD risk demonstrated a significant risk reduction.ConclusionsProbiotics are effective for preventing AAD. Secondary analyses of higher dosages and certain species have shown increased effectiveness. Our results may not be applicable in clinical scenarios of lower baseline AAD risk.
Point-of-care testing and treatment of sexually transmitted and genital infections during pregnancy in Papua New Guinea (WANTAIM trial): protocol for an economic evaluation alongside a cluster-randomised trial
Authors: Batura Neha , Saweri Olga PM , Vallely Andrew , Pomat William , Homer Caroline , Guy Rebecca , Luchters Stanley , Mola Glen , Vallely Lisa M , Morgan Christopher , Kariwiga Grace , Wand Handan , Rogerson Stephen , Tabrizi Sepehr N , Whiley David M , Low Nicola , Peeling Rosanna W , Siba Peter M , Riddell Michaela , Laman Moses , Bolnga John , Robinson Leanne J , Morewaya Jacob , Badman Steven , Kelly-Hanku Angela , Toliman Pamela J , Peter Wilfred , Peach Elizabeth , Garland Suzanne , Kaldor John , Wiseman Virginia 
Published: August 2021

IntroductionLeft untreated, sexually transmitted and genital infections (henceforth STIs) in pregnancy can lead to serious adverse outcomes for mother and child. Papua New Guinea (PNG) has among the highest prevalence of curable STIs including syphilis, chlamydia, gonorrhoea, trichomoniasis and bacterial vaginosis, and high neonatal mortality rates. Diagnosis and treatment of these STIs in PNG rely on syndromic management. Advances in STI diagnostics through point-of-care (PoC) testing using GeneXpert technology hold promise for resource-constrained countries such as PNG. This paper describes the planned economic evaluation of a cluster-randomised cross-over trial comparing antenatal PoC testing and immediate treatment of curable STIs with standard antenatal care in two provinces in PNG.Methods and analysisCost-effectiveness of the PoC intervention compared with standard antenatal care will be assessed prospectively over the trial period (2017–2021) from societal and provider perspectives. Incremental cost-effectiveness ratios will be calculated for the primary health outcome, a composite measure of the proportion of either preterm birth and/or low birth weight; for life years saved; for disability-adjusted life years averted; and for non-health benefits (financial risk protection and improved health equity). Scenario analyses will be conducted to identify scale-up options, and budget impact analysis will be undertaken to understand short-term financial impacts of intervention adoption on the national budget. Deterministic and probabilistic sensitivity analysis will be conducted to account for uncertainty in key model inputs.Ethics and disseminationThis study has ethical approval from the Institutional Review Board of the PNG Institute of Medical Research; the Medical Research Advisory Committee of the PNG National Department of Health; the Human Research Ethics Committee of the University of New South Wales; and the Research Ethics Committee of the London School of Hygiene and Tropical Medicine. Findings will be disseminated through national stakeholder meetings, conferences, peer-reviewed publications and policy briefs.Trial registration numberISRCTN37134032.
Stakeholder engagement in economic evaluation: Protocol for using the nominal group technique to elicit patient, healthcare provider, and health system stakeholder input in the development of an early economic evaluation model of chimeric antigen receptor T-cell therapy
Authors: Wilson Mackenzie , Thavorn Kednapa , Hawrysh Terry , Graham Ian D , Atkins Harold , Kekre Natasha , Coyle Doug , Lalu Manoj M , Fergusson Dean A , Chan Kelvin KW , Ollendorf Daniel A , Presseau Justin 
Published: August 2021

IntroductionChimeric antigen receptor T-cell (CAR-T) therapy is a class of immunotherapy. An economic evaluation conducted at an early stage of development of CAR-T therapy for treatment of adult relapsed or refractory acute lymphoblastic leukaemia could provide insight into factors contributing to the cost of treatment, the potential clinical benefits, and what the health system can afford. Traditionally, stakeholders are engaged in certain parts of health technology assessment processes, such as in the identification and selection of technologies, formulation of recommendations, and implementation of recommendations; however, little is known about processes for stakeholder engagement during the conduct of the assessment. This is especially the case for economic evaluations. Stakeholders, such as clinicians, policy-makers, patients, and their support networks, have insight into factors that can enhance the validity of an economic evaluation model. This research outlines a specific methodology for stakeholder engagement and represents an avenue to enhance health economic evaluations and support the use of these models to inform decision making for resource allocation. This protocol may inform a tailored framework for stakeholder engagement processes in future economic evaluation model development.Methods and analysisWe will involve clinicians, healthcare researchers, payers, and policy-makers, as well as patients and their support networks in the conduct and verification of an early economic evaluation of a novel health technology to incorporate stakeholder-generated knowledge. Three stakeholder-specific focus groups will be conducted using an online adaptation of the nominal group technique to elicit considerations from each. This study will use CAR-T therapy for adults with relapsed or refractory B-cell acute lymphoblastic leukaemia as a basis for investigating broader stakeholder engagement processes.Ethics and disseminationThis study received ethics approval from the Ottawa Hospital Research Institute Research Ethics Board (REB 20200320-01HT) and the results will be shared via conference presentations, peer-reviewed publications, and ongoing stakeholder engagement.
Opioid analgesic use after ambulatory surgery: a descriptive prospective cohort study of factors associated with quantities prescribed and consumed
Authors: Shanahan Christopher W , Reding Olivia , Holmdahl Inga , Keosaian Julia , Xuan Ziming , McAneny David , Larochelle Marc , Liebschutz Jane 
Published: August 2021

ObjectivesTo prospectively characterise: (1) postoperative opioid analgesic prescribing practices; (2) experience of patients undergoing elective ambulatory surgeries and (3) impact of patient risk for medication misuse on postoperative pain management.DesignLongitudinal survey of patients 7 days before and 7–14 days after surgery.SettingAcademic urban safety-net hospital.Participants181 participants recruited, 18 surgeons, follow-up data from 149 participants (82% retention); 54% women; mean age: 49 years.InterventionsNone.Primary and secondary outcome measuresTotal morphine equivalent dose (MED) prescribed and consumed, percentage of unused opioids.ResultsSurgeons postoperatively prescribed a mean of 242 total MED per patient, equivalent to 32 oxycodone (5 mg) pills. Participants used a mean of 116 MEDs (48%), equivalent to 18 oxycodone (5 mg) pills (~145 mg of oxycodone remaining per patient). A 10-year increase in patient age was associated with 12 (95% CI (−2.05 to –0.35)) total MED fewer prescribed opioids. Each one-point increase in the preoperative Graded Chronic Pain Scale was associated with an 18 (6.84 to 29.60) total MED increase in opioid consumption, and 5% (−0.09% to –0.005%) fewer unused opioids. Prior opioid prescription was associated with a 55 (5.38 to –104.82) total MED increase in opioid consumption, and 19% (−0.35% to –0.02%) fewer unused opioids. High-risk drug use was associated with 9% (−0.19% to 0.002%) fewer unused opioids. Pain severity in previous 3 months, high-risk alcohol, use and prior opioid prescription were not associated with postoperative prescribing practices.ConclusionsParticipants with a preoperative history of chronic pain, prior opioid prescription, and high-risk drug use were more likely to consume higher amounts of opioid medications postoperatively. Additionally, surgeons did not incorporate key patient-level factors (eg, substance use, preoperative pain) into opioid prescribing practices. Opportunities to improve postoperative opioid prescribing include system changes among surgical specialties, and patient education and monitoring.
Effects of the COVID-19 pandemic on the follow-up and treatment of patients with idiopathic pulmonary fibrosis: a cross-sectional, multicentre phone call survey
Authors: Coskun Funda , Hanta Ismail , Cilli Aykut , Ozkaya Guven , Ursavas Ahmet , Sevinc Can 
Published: August 2021

ObjectiveTo learn about the attitudes and behaviours of patients with idiopathic pulmonary fibrosis (IPF) in relation to the difficulties experienced during the COVID-19 pandemic.DesignA cross-sectional, multicentre phone call survey.SettingFour university hospitals in Turkey.ParticipantsThe study included patients with IPF receiving antifibrotics for at least 3 months and with doctor appointment and/or scheduled routine blood analysis between March and May 2020 (the first 3 months after the official announcement of the COVID-19 pandemic in Turkey).InterventionsPhone calls (a 5 min interview) were performed in June 2020. A questionnaire and the Hospital Anxiety-Depression Scale were applied.Main outcome measuresPatients’ preferences for disease monitoring, patients’ attitudes and behaviours towards IPF, drug continuation, COVID-19 diagnosis and anxiety/depression status.ResultsThe study included 115 patients with IPF (82 male; mean age, 68.43±7.44 years). Of the patients, 73.9% had doctor appointment and 52.2% had scheduled routine blood testing; 54.5% of patients with doctor appointment self-cancelled their appointments and 53.3% of patients with scheduled routine blood testing did not undergo testing. Of the patients, 32.2% were on nintedanib and 67.8% were on pirfenidone; self-initiated drug discontinuation rate was 22.6%. The percentage of patients communicating with their physicians was 35.7%. The route of communication was by phone (34.8%). The frequency of depression and anxiety was 27.0% and 38.3%, respectively. The rates of drug discontinuation (35.1% vs 16.7%, p<0.05) and depression (37.8% vs 21.8%, p=0.07) were higher in nintedanib users than in pirfenidone users. Only two (1.7%) patients had COVID-19 diagnosis.ConclusionsDuring the COVID-19 pandemic, a significant proportion (>50%) of patients self-cancelled their appointments and nearly a quarter of patients discontinued their medications. Providing a documentation of the problems experienced by patients with IPF about management of the necessary requirements during the COVID-19 pandemic, this study may be a model for patients with chronic diseases.