bluuebunny/crossref_metadata_2025_split huggingface dataset:
When mechanical work meets energetics: Obese versus non‐obese children walking
Authors: Oliveira Henrique Bianchi , da Rosa Rodrigo Gomes , Gomeñuka Natalia Andrea , Carvalho Alberito Rodrigo de , Costa Roberto Fernandes da , Peyré‐Tartaruga Leonardo Alexandre 
Published: May 2020

New Findings
What is the central question of this study?
The aim was to compare the cost of transport and mechanical work between obese and non‐obese children at different walking speeds.
What is the main finding and its importance?
Our data show that the cost of transport, mechanical efficiency and work are similar and directly mass dependent in obese and non‐obese children. The optimal walking speed (most economical walking speed) is reduced in obese children.
AbstractAlthough studies have shown the influence of gait biomechanics on the metabolic economy in obese adults and adolescents, little is known regarding obese children. We compared the metabolic cost of transport, apparent mechanical efficiency and gait biomechanics (assessed by mechanical energy fluctuations) in obese children (n = 12; mean ± SD: 8.6 ± 0.51 years of age, 1.38 ± 0.04 m, 44.6 ± 6.65 kg, 24.1 ± 3.50 kg m−2) and age‐ and sex‐matched non‐obese children (n = 12, 7.8 ± 0.90 years of age, 1.31 ± 0.08 m, 26.8 ± 2.24 kg, 16.4 ± 1.40 kg m−2) while walking at different speeds (from 1 to 5 km h−1) on a treadmill. We found that the mechanical efficiency was higher at 3 km h−1 compared with the remaining speeds for both groups (P < 0.05). Although the internal mechanical work has been greater in obese compared with non‐obese children at 4 and 5 km h−1, the external, total mechanical work and the mechanical efficiency remained similar between obese and non‐obese children at all speeds. Likewise, the cost of transport was similar in the two groups, although the optimal walking speed was an average of 0.4 km h−1 slower in obese children. Clearly, these results show that the walking economy is associated with the total mechanical work in obese and non‐obese children. Finally, the reduced functional mobility in obese children observed in previous studies seems to be associated with a reduction in optimal walking speed in comparison to non‐obese children.
Numerical Investigation of the Effects of Swirling Hot Co-Flow on MILD Combustion of a Hydrogen–Methane Blend
Authors: Mousavi Seyed Mahmood , Kamali Reza , Sotoudeh Freshteh , Karimi Nader , Jeung In-Seuck 
Published: May 2020

Abstract
This paper examines the effects of swirl hot co-flow on the combustion behavior of a moderate or intense low oxygen dilution (MILD) burner fueled by a mixture of methane and hydrogen. Toward this goal, the realizable k-ɛ turbulence model, GRI. 2.11 reaction mechanism, and the discrete ordinates radiation model are incorporated into a computational modeling of the reactive flow. The numerical results are, first, favorably compared against the existing experimental data. Subsequently, a number of swirl co-flows are implemented, and structures of the resultant reactive flows are investigated systematically. The outcomes indicate that increasing the swirl velocity leads to the reduction of ignition delay and significantly enhances the reaction completion. The analysis of the spatial distribution of hydroxyl and formyl (OH and HCO) radicals reveals that swirling MILD combustion radially extends the reaction zone in comparison with the conventional MILD combustion. Yet, it reduces the length of the reactive region and allows for the occurrence of heat release in a shorter axial distance from the outlet fuel nozzle. Further, the addition of swirl reduces the production of carbon monoxide through its influences upon flow temperature and generation of formyl radical. However, it is found that swirling hot co-flow intensifies NOx emissions by strengthening of prompt and thermal mechanisms of NOx production. Reducing the temperature of the recycled flue gas is deemed to be an effective way of resolving this issue.
PTFE Modification to Enhance Boiling Performance of Porous Surface
Authors: Wang Ya-Qiao , Luo Jia-Li , Heng Yi , Mo Dong-Chuan , Lyu Shu-Shen 
Published: May 2020

Abstract
Boiling heat transfer is one of the most effective methods to meet the challenge of heat dissipation of high heat flux devices. A wetting hybrid surface has been shown to have better performance than the hydrophilic or hydrophobic surface. This kind of wetting hybrid modification is always carried out on a plain or flat surface. In this paper, polytetrafluoroethylene (PTFE) powders were coated on a superhydrophilic microcopper dendrite fin surface to build a wetting hybrid surface. The pool-boiling experimental results showed that after applying the coating, the wall superheat dramatically decreased to 8 K, which is 9 K lower than that on the original surface at 250 W·cm−2, and has a better performance than a silicon pin-fin-based wetting hybrid surface.
Impact Analysis of Inline Inspection Accuracy on Pipeline Integrity Planning
Authors: Xie Mingjiang , Sutherland Jeff , Fang Bingyan , Gu Bill , Tian Zhigang 
Published: May 2020

Abstract
Integrity planning methods and inline inspection (ILI) tool performance have a great impact on a pipeline integrity management program. In pipeline integrity planning, risk and integrity assessments are performed to schedule integrity activities like ILI for the purpose of reducing risks and ensuring reliable and safe operations. In this paper, a method is developed for analyzing the impact of ILI tool accuracy on pipeline integrity planning, which is of great importance but has not been systematically studied before. Crack inspection and threat of fatigue cracking are used as the working case for the analysis, although the approach could potentially be used for any pipeline threat type. The Paris' law degradation model is used for the crack growth and subsequent severity and risk assessment. We investigated the impact of ILI tool accuracy on the cost rate, as well as the associated inspection intervals. The impact on long-term cost rate was also investigated considering new defect generation and continuous growth. Sensitivity analyses were performed. The optimal inspection intervals and the corresponding total cost rates with respect to different ILI tool accuracy and different input parameters were obtained and compared. The proposed method can support integrity management program planning by linking risks with integrity plan costs associated with ILI accuracy and optimal re-assessment intervals. The contributions of this paper mainly include the investigation of the problem of how ILI tool accuracy impacts integrity planning, the development of the method for analyzing pipelines with cracks, and the verification and validation with the examples.
Study on Fuel and Injection Influence on a Spark Ignition Aeropiston Engine
Authors: Xiaogang Wang , Bolan Liu , Xiyang Yu , Chao Yan , Fei Yu , Zhenfeng Zhao 
Published: May 2020

Abstract
Spark ignition aeropiston engines have good prospects due to light weight and high power to weight ratio. Both gasoline and kerosene can be utilized on these engines by using either traditional port fuel injection (PFI) or the novel air-assisted fuel injection (A2FI). In this article, the effects of different fuels and injection methods on the performance of a four-cylinder opposed aeropiston engine were studied. The spray performance test rig and the engine performance test rig were established. First, the influence of different injection methods on engine performance were compared, which indicated that A2FI is superior to PFI in engine power and starting performance. Furthermore, the fuel performance comparison by using A2FI was conducted, which demonstrates that kerosene is inferior to gasoline in terms of spray characteristics and power performance. Finally, detailed working characteristics of A2FI system using kerosene were studied, which indicated that the stable and reliable operation of the spark-ignition operation can be realized and the kerosene's spark-ignition combustion process can be optimized similar to that of gasoline. Results shows that the use of kerosene combined with A2FI is the best technical way to achieve ideal working process of the spark ignition aeropiston engine.
A Novel Single-Passage Transonic Wind Tunnel for Turbine-Vane Film Cooling
Authors: Qenawy Mohamed , Yuan Lin , Liu Yingzheng , Peng Di , Wen Xin , Zhou Wenwu 
Published: May 2020

Abstract
Wind-tunnel testing of turbines cascade is an important technique for quantifying the realistic conditions of turbine-vane film cooling. However, the complex and expensive facilities needed for the multipassage design of such wind tunnels have prompted the introduction of the single-passage design strategy. In this contribution, detailed procedures for building a novel single-passage transonic wind-tunnel using additive manufacturing are presented. In addition, the detailed flow structure caused by the passage was investigated. The proposed design was evaluated step-by-step using an integrated model that successively comprised two-dimensional (2D) periodic passage simulation, 2D single-passage simulation, three-dimensional (3D) single-passage simulation, construction, and testing. The proposed design was found to achieve flow periodicity at transonic flow conditions with relatively low-flow consumption. The results were validated by comparison to the available literature data. In addition, an endwall-cooling configuration was successfully deployed using fast-response pressure-sensitive paint (fast-PSP). This study, combined with the help of commercial software and 3D printing, shed light upon strategies for time- and cost-reduction in linear cascade design, which could benefit the turbomachinery community.
Nearly Efficiency-Droop-Free AlGaN-Based Deep-Ultraviolet Light-Emitting Diode Without Electron-Blocking Layer
Authors: Jia Hongfeng , Yu Huabin , Ren Zhongjie , Xing Chong , Liu Zhongling , Kang Yang , Sun Haiding 
Published: May 2020

Abstract
An aluminum-rich AlGaN layer is commonly implemented to act as an electron-blocking layer (EBL) to block electron overflow from the active region in the conventional deep-ultraviolet light-emitting diodes (DUV LEDs). Herein, we propose a DUV LED device architecture with specially designed band-engineered quantum barriers (QBs) to “serve” as an alternative approach to alleviate such overflow effect, suppressing the electron leakage, and facilitating the electron and hole injection into the active region for efficient radiative recombination. Intriguingly, a much smaller efficiency droop with a significant enhancement of light output power (LOP) by nearly 50% can be achieved at the injection current level of 120 mA in such EBL-free device, in comparison with the conventional EBL-incorporated DUV LED structure. Thus, the EBL-free device architecture provides us an alternative path toward the realization of efficient DUV light emitters.
Factors associated with hospital admission and critical illness among 5279 people with coronavirus disease 2019 in New York City: prospective cohort study
Authors: Petrilli Christopher M , Jones Simon A , Yang Jie , Rajagopalan Harish , O’Donnell Luke , Chernyak Yelena , Tobin Katie A , Cerfolio Robert J , Francois Fritz , Horwitz Leora I 
Published: May 2020

AbstractObjectiveTo describe outcomes of people admitted to hospital with coronavirus disease 2019 (covid-19) in the United States, and the clinical and laboratory characteristics associated with severity of illness.DesignProspective cohort study.SettingSingle academic medical center in New York City and Long Island.Participants5279 patients with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection between 1 March 2020 and 8 April 2020. The final date of follow up was 5 May 2020.Main outcome measuresOutcomes were admission to hospital, critical illness (intensive care, mechanical ventilation, discharge to hospice care, or death), and discharge to hospice care or death. Predictors included patient characteristics, medical history, vital signs, and laboratory results. Multivariable logistic regression was conducted to identify risk factors for adverse outcomes, and competing risk survival analysis for mortality.ResultsOf 11 544 people tested for SARS-Cov-2, 5566 (48.2%) were positive. After exclusions, 5279 were included. 2741 of these 5279 (51.9%) were admitted to hospital, of whom 1904 (69.5%) were discharged alive without hospice care and 665 (24.3%) were discharged to hospice care or died. Of 647 (23.6%) patients requiring mechanical ventilation, 391 (60.4%) died and 170 (26.2%) were extubated or discharged. The strongest risk for hospital admission was associated with age, with an odds ratio of >2 for all age groups older than 44 years and 37.9 (95% confidence interval 26.1 to 56.0) for ages 75 years and older. Other risks were heart failure (4.4, 2.6 to 8.0), male sex (2.8, 2.4 to 3.2), chronic kidney disease (2.6, 1.9 to 3.6), and any increase in body mass index (BMI) (eg, for BMI >40: 2.5, 1.8 to 3.4). The strongest risks for critical illness besides age were associated with heart failure (1.9, 1.4 to 2.5), BMI >40 (1.5, 1.0 to 2.2), and male sex (1.5, 1.3 to 1.8). Admission oxygen saturation of <88% (3.7, 2.8 to 4.8), troponin level >1 (4.8, 2.1 to 10.9), C reactive protein level >200 (5.1, 2.8 to 9.2), and D-dimer level >2500 (3.9, 2.6 to 6.0) were, however, more strongly associated with critical illness than age or comorbidities. Risk of critical illness decreased significantly over the study period. Similar associations were found for mortality alone.ConclusionsAge and comorbidities were found to be strong predictors of hospital admission and to a lesser extent of critical illness and mortality in people with covid-19; however, impairment of oxygen on admission and markers of inflammation were most strongly associated with critical illness and mortality. Outcomes seem to be improving over time, potentially suggesting improvements in care.
The cost-effectiveness of using results-based financing to reduce maternal and perinatal mortality in Malawi
Authors: Chinkhumba Jobiba , De Allegri Manuela , Brenner Stephan , Muula Adamson , Robberstad Bjarne 
Published: May 2020

IntroductionResults-based financing (RBF) is being promoted to increase coverage and quality of maternal and perinatal healthcare in sub-Saharan Africa (SSA) countries. Evidence on the cost-effectiveness of RBF is limited. We assessed the cost-effectiveness within the context of an RBF intervention, including performance-based financing and conditional cash transfers, in rural Malawi.MethodsWe used a decision tree model to estimate expected costs and effects of RBF compared with status quo care during single pregnancy episodes. RBF effects on maternal case fatality rates were modelled based on data from a maternal and perinatal programme evaluation in Zambia and Uganda. We obtained complementary epidemiological information from the published literature. Service utilisation rates for normal and complicated deliveries and associated costs of care were based on the RBF intervention in Malawi. Costs were estimated from a societal perspective. We estimated incremental cost-effectiveness ratios per disability adjusted life year (DALY) averted, death averted and life-year gained (LYG) and conducted sensitivity analyses to how robust results were to variations in key model parameters.ResultsRelative to status quo, RBF implied incremental costs of US$1122, US$26 220 and US$987 per additional DALY averted, death averted and LYG, respectively. The share of non-RBF facilities that provide quality care, life expectancy of mothers at time of delivery and the share of births in non-RBF facilities strongly influenced cost-effectiveness values. At a willingness to pay of US$1485 (3 times Malawi gross domestic product per capita) per DALY averted, RBF has a 77% probability of being cost-effective.ConclusionsAt high thresholds of wiliness-to-pay, RBF is a cost-effective intervention to improve quality of maternal and perinatal healthcare and outcomes, compared with the non-RBF based approach. More RBF cost-effectiveness analyses are needed in the SSA region to complement the few published studies and narrow the uncertainties surrounding cost-effectiveness estimates.
Sex-based impact of carotid plaque in patients with chest pain undergoing stress echocardiography
Authors: Ahmadvazir Shahram , Pradhan Jiwan , Khattar Rajdeep Singh , Senior Roxy 
Published: May 2020

ObjectiveWomen with suspected angina without history of coronary artery disease (CAD) less frequently have flow-limiting stenosis (FL-CAD) and more often have microvascular disease, affecting predictive accuracy of stress echocardiography (SE) for detection of FL-CAD. We postulated that carotid plaque burden (CPB) assessment would improve detection of FL-CAD and risk stratification.MethodsConsecutive consenting patients assessed by SE on clinical grounds for new-onset chest pain also underwent simultaneous carotid ultrasound. Patients were followed for major adverse events (MAE): all-cause mortality, non-fatal myocardial infarction and unplanned revascularisation. Carotid plaque presence and burden (CPB) were assessed.ResultsAfter a mean of 2617±469 days (range 17–3740), of 591 recruited patients, 573 (97%) outcome data (314 females) were obtainable. Despite lower pretest probability of CAD in females versus males (14.9±0.8 vs 20.5±1.3, respectively, p<0.0001), prevalence of myocardial ischaemia was similar (p=0.08). Females also had lower prevalence of both carotid plaque (p<0.0001) and FL-CAD (p<0.05). CPB improved the positive predictive value of SE for detection of FL-CAD (from 34.5% to 60%) in females but not in males. Absence of CPB in females with myocardial ischaemia ruled out FL-CAD in 93% versus 57% in males. CPB was the only independent predictor of MAE (p=0.012) in females, whereas in males both SE (p<0.0001) and CPB (p=0.003) remained significant.ConclusionIn females with new-onset stable angina without a history of cardiovascular disease, CPB improved the predictive accuracy of myocardial ischaemia for flow-limiting CAD. However, CPB provided incremental risk stratification in both sexes.
Neutrophil and lymphocyte counts are associated with different immunopathological mechanisms in systemic lupus erythematosus
Authors: Han Bobby Kwanghoon , Wysham Katherine D , Cain Kevin C , Tyden Helena , Bengtsson Anders A , Lood Christian 
Published: May 2020

ObjectiveNeutrophils contribute to the SLE pathogenesis. Neutrophil to lymphocyte ratio (NLR) is reported to correlate with disease activity in SLE. The aim of the study was to evaluate whether NLR reflects underlying immunopathogenic activity in SLE, as well as to determine the contribution of each component of NLR, neutrophil and lymphocyte count.MethodsData were obtained from a cohort of patients with SLE (n=141) recruited at Lund University, Sweden. NLR levels were compared between patients with SLE and healthy controls (n=79). The relationship between NLR and clinical and immunological markers was examined using Mann-Whitney U test and logistic regression analysis. High NLR was defined as above the 90th percentile of healthy individuals.ResultsPatients with SLE had elevated neutrophil count (p=0.04) and reduced lymphocyte count (p<0.0001), resulting in elevated NLR as compared with healthy controls (p<0.0001). Patients with high NLR had more active disease, and were more frequently on prednisone use and immunosuppressive medicines. High NLR was associated with immune complex (IC)-driven disease with presence of antidouble-stranded DNA antibodies (p=0.006), circulating ICs (p=0.02) and type I interferon (IFN) activity (p=0.009). Further, high NLR was associated with neutrophil abnormalities, including enrichment for low-density granulocytes (LDGs) (p=0.001), and increased levels of the serum neutrophil activation marker, calprotectin (p=0.02). Assessing the individual components within NLR, that is, neutrophil and lymphocyte count, high neutrophil count was associated with neutrophil activation markers (p<0.0001), whereas low lymphocyte count was associated with type I IFN activity and elevated numbers of LDGs (p=0.006 and p=0.001, respectively).ConclusionsNLR is elevated in patients with SLE as compared with healthy individuals, and is associated with key immunopathological events, including type I IFN activity and neutrophil activation. Neutrophil and lymphocyte count reflected different aspects of the pathogenesis of SLE. Further studies are needed to determine the causality of the associations.
Spirometry performed as part of the Manchester community-based lung cancer screening programme detects a high prevalence of airflow obstruction in individuals without a prior diagnosis of COPD
Authors: Balata Haval , Harvey Jonathan , Barber Phil V , Colligan Denis , Duerden Rebecca , Elton Peter , Evison Matthew , Greaves Melanie , Howells John , Irion Klaus , Karunaratne Devinda , Mellor Stuart , Newton Tom , Sawyer Richard , Sharman Anna , Smith Elaine , Taylor Ben , Taylor Sarah , Tonge Janet , Walsham Anna , Whittaker James , Vestbo Joergen , Booton Richard , Crosbie Phil A 
Published: May 2020

BackgroundCOPD is a major cause of morbidity and mortality in populations eligible for lung cancer screening. We investigated the role of spirometry in a community-based lung cancer screening programme.MethodsEver smokers, age 55–74, resident in three deprived areas of Manchester were invited to a ‘Lung Health Check’ (LHC) based in convenient community locations. Spirometry was incorporated into the LHCs alongside lung cancer risk estimation (Prostate, Lung, Colorectal and Ovarian Study Risk Prediction Model, 2012 version (PLCOM2012)), symptom assessment and smoking cessation advice. Those at high risk of lung cancer (PLCOM2012 ≥1.51%) were eligible for annual low-dose CT screening over two screening rounds. Airflow obstruction was defined as FEV1/FVC<0.7. Primary care databases were searched for any prior diagnosis of COPD.Results99.4% (n=2525) of LHC attendees successfully performed spirometry; mean age was 64.1±5.5, 51% were women, 35% were current smokers. 37.4% (n=944) had airflow obstruction of which 49.7% (n=469) had no previous diagnosis of COPD. 53.3% of those without a prior diagnosis were symptomatic (n=250/469). After multivariate analysis, the detection of airflow obstruction without a prior COPD diagnosis was associated with male sex (adjOR 1.84, 95% CI 1.37 to 2.47; p<0.0001), younger age (p=0.015), lower smoking duration (p<0.0001), fewer cigarettes per day (p=0.035), higher FEV1/FVC ratio (<0.0001) and being asymptomatic (adjOR 4.19, 95% CI 2.95 to 5.95; p<0.0001). The likelihood of screen detected lung cancer was significantly greater in those with evidence of airflow obstruction who had a previous diagnosis of COPD (adjOR 2.80, 95% CI 1.60 to 8.42; p=0.002).ConclusionsIncorporating spirometry into a community-based targeted lung cancer screening programme is feasible and identifies a significant number of individuals with airflow obstruction who do not have a prior diagnosis of COPD.