bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thyroid function control among pregnant women following a therapeutic thyroidectomy
Authors: Horowitz Gilad , Ish‐Shalom Maya , Warshavsky Anton , Stern Naftali , Fliss Dan M. , Comaneshter Doron , Vinker Shlomo 
Published: December 2020

AbstractObjectivesThe aim of this study was to assess the extent of thyroid function control among pregnant women who had previously undergone a therapeutic thyroidectomy.DesignRetrospective cohort study.SettingThe largest health maintenance organization in Israel.ParticipantsAll female patients who were pregnant between May, 2001 and September, 2012 and had a medical history of thyroid surgery.Main outcome measureThe thyroid‐stimulating hormone (TSH) levels throughout the pregnancy were compared to recommended trimestral values. A multivariate analysis was performed to determine risk factors for not attaining TSH recommended range.ResultsA total of 477 females with a history of thyroid surgery had given 701 births during the study period. Forty‐three percent (n = 203), had thyroidal malignancy. Nearly half of the women underwent total thyroidectomy (43.4%, n = 207). The women’s TSH values were within the recommended range in only 60% (n = 350) of the pregnancies during the first trimester (0.1‐2.5 mIU/L), in 61% (n = 335) during the second trimester (0.2‐3 mIU/L), and in 70% (n = 338) during the third trimester (0.3‐3 mIU/L). In multivariate analysis, women that underwent a total thyroidectomy due to a benign thyroid disease, were at the highest risk for not attaining target TSH levels.ConclusionsThis very large cohort of pregnant women with a past history of thyroid surgery demonstrated a significant percentage of pregnancies with TSH values above the recommended range. Women that underwent a total thyroidectomy due to benign thyroid disease were at the highest risk for gestational hypothyroidism.
Chronic limb‐threatening ischaemia and reframing the meaning of ‘end’
Authors: Monaro Susan , West Sandra , Gullick Janice 
Published: December 2020

AbstractIntroductionThe possibility of amputation and/or death from chronic limb‐threatening ischaemia (CLTI) is real, and deeper understandings of the person and family's capacity and preparedness for limb loss and clinical interventions (active or palliative) are required.BackgroundThe lead‐in period to the surgeon's recommendation for amputation for CLTI may be sudden or protracted; the number/invasiveness of previous revascularisation interventions varies, and limb loss and end‐of‐life considerations frame the experience.MethodThis prospective, longitudinal, interpretative phenomenological study in three vascular surgical units involved 19 CLTI journeys. Participants were interviewed when making decisions about amputation (15 patients, 12 family members) and, where applicable, 6‐months postamputation (8 patients, 7 family members). Hermeneutic interpretation using Heidegger's philosophical construct of Being‐towards‐death guided the analysis. The COREQ checklist ensured rigour in research reporting.FindingsSome participants were unable to face the possibility of death and metaphorically ‘fled’, either through productive optimism or through hoping for more time (Heidegger's inauthentic positioning towards death). For others, authentic positionings of Being‐towards‐death were understood as: the confrontation of the certainty of their death by making choices about how to die; the indefiniteness of death where treatment choices influenced timing, yet the time for death remained unknown; the nonrelational nature of death, as the journey could only be lived by the person; and death as not to be outstripped, where for some, there was a freeing of oneself for amputation and/or death.DiscussionThe term ‘end of limb’ to denote the futility of the limb is a useful marker that emphasises the noncurative nature of CLTI. This may help to instigate and support discussions about end of life to support palliation care planning and the person and family's existential preparation for death.ConclusionDeath frames the experience of CLTI. Using ‘end‐of‐limb’ and ‘end‐of‐life’ terminology may facilitate a family/patient‐centred approach to possible amputation and other conservative or palliative strategies.Relevance to Clinical Practice

Understanding of CLTI illness experience.

Decisions about revascularisation, amputation or conservative care.

End‐of‐life care for CLTI.
Tissue biomarkers for predicting the risk of oral cancer in patients diagnosed with oral leukoplakia: A systematic review
Authors: Monteiro Luis , Mello Fernanda Weber , Warnakulasuriya Saman 
Published: December 2020

AbstractObjectivesWe performed a systematic review to evaluate the published biomarkers related to oral leukoplakia (OL), aiming to identify the biomarkers that indicate any future risk of cancer in patients with oral leukoplakia.MethodsA search strategy was developed for three main electronic databases: PubMed, Cochrane Library, and EBSCO, and also for Google Scholar, until February 28, 2020. The study selection was performed in a two‐phase process aiming at studies assessing tissue biomarkers for “malignant transformation of OL.” Risk of bias analysis of included studies was performed using the Quality in Prognosis Studies Tool.ResultsFrom 3,130 articles initially identified by searching databases, a total of 46 studies were included in this systematic review, with a combined sample of 3,783 patients, of whom 1,047 presented with malignant transformation of a previously diagnosed OL as reported by the authors. The cancer incidence in the whole group was 27.6% (range: 5.4% to 54.1%). The studies were derived from different geographic areas, including Asia (n = 21), Europe (n = 15), North America (n = 9), and Oceania (n = 1). There were 49 different molecular biomarkers evaluated in the 46 included studies: p53 and podoplanin proteins were the most frequently reported, followed by abnormalities at particular chromosomal loci (e.g., LOH). Risk of bias analysis revealed concerns associated with “measurement of prognostic factor,” “study confounding” and “statistical analysis and reporting.”ConclusionsSubstantial heterogeneity and lack of standardized reporting of data among the studies were identified. The most promising biomarkers reported to have a significant association with the malignant transformation in OL included podoplanin and chromosomal loci abnormalities. A critical examination of the follow‐up studies on OL published so far indicated that tissue biomarkers that could predict the risk of oral cancer in patients with OL are still in a discovery phase.
Detailed Numerical Comparison of Laminar Burning Speed of Stratified Hydrogen–Air and Methane–Air Mixture With Corresponding Homogeneous Mixture Using Open-Source Code
Authors: Rizvi Mohammad Sadik 
Published: December 2020

Abstract
A detailed numerical study of laminar burning speed for fuel–air mixture is conducted using laminarReactingLMFoam solver which is a modified version of reactingFoam solver based on openfoam code. It accounts for detailed mixture-averaged transport property calculation for reacting flow using low-Mach number governing equations. The effect of various equivalence ratio gradients is studied on stratified hydrogen–air and methane–air mixture with mixture-averaged transport model and unity Lewis number for all species, and corresponding laminar burning speed is compared with homogeneous mixture. For both the fuel–air mixture, rich to lean stratified mixture resulted in a higher laminar burning speed and no significant difference was noticed for lean to rich stratified mixture when compared with homogeneous mixture at same local equivalence ratio. Increased burning speed is explained based on higher burnt gas temperature and molecular diffusion of lighter species from burnt gas referred to “Chemical Effect” in this study. The effect of thermal and molecular diffusion from the burnt gas on laminar burning speed is studied for stratified and homogeneous mixture using mixture-averaged transport model and unity Lewis number for all species. It is shown that the molecular diffusion effect from burnt gas (“Chemical Effect”) is more prominent as compared with the thermal diffusion effect. Extension in lean flammability limit for stratified mixture of both the fuel is shown based on higher heat release rate as compared with homogeneous mixture and extension in flammability limit for stratified mixture is explained based on higher Chemical Effect from burnt gas.
Role of a Sinusoidal Wavy Surface in Enhancement of Heat Transfer Using Turbulent Dual Jet
Authors: Singh Tej Pratap , Kumar Amitesh , Satapathy Ashok Kumar 
Published: December 2020

Abstract
In this paper, the role of sinusoidal wavy surface in enhancing the heat transfer is numerically studied. The heat transfer characteristics are studied for two thermal boundary conditions of the wavy wall. To assess the effect of wavy wall, the amplitude is varied between 0.1 and 0.7 and number of cycle from 4 to 12 at an interval of 0.1 and 1, respectively. In order to see the effect of offset ratio, it is varied between 3 and 15 at an interval of 2. The Reynolds number (Re) and Prandtl number (Pr) are set to 15, 000 and 0.71, respectively, for all the numerical simulations. It is found that the maximum average Nusselt number (Nuavg) depends not only on the amplitude and number of cycle but also on the offset ratio. Overall, 23.27% in maximum heat transfer enhancement is achieved with reference to the plane wall surface. An approximately linear decrement in maximum Nuavg is observed when offset ratio increases. The results indicate that Nuavg increases with an increase in the amplitude of sinusoidal wavy surface up to N = 8 and almost follows the linear trend up to N = 7. It is also found that Nux is always on the higher side as compared to the corresponding case of a plane wall surface when N = 4, irrespective of the offset ratio. With an increase in N, Nux fluctuates about the result of plane wall surface after the initial increase because of the obstruction. The amplitude of the fluctuation increases with an increase in the number of cycle N, which indicates that fluid accelerates and decelerates gradually owing to the presence of trough and crest. Also, it is worth noticing that for some cases, there is a decrease in the heat transfer rate as compared to the plane wall case. Therefore, it is concluded that the increase in the surface area does not necessarily result in an increase in the heat transfer rate.
Effects of Oxygenated Biomass Fuels on the Performance of Diesel Engine and After-Treatment System
Authors: Zhang Jingxian , Chen Guisheng , Shen Yinggang , Li Bing , Li Qing 
Published: December 2020

Abstract
Oxygenated biomass fuels have attracted significant attention due to their contributions in reducing environmental pollution and fossil fuel consumption. In view of stricter emission regulations, the use of these alternative fuels cannot fully meet the requirements, and it needs to be combined with an after-treatment system. In this article, polymethoxy dimethyl ether (PODE) and n-pentanol were blended with diesel (D100 (pure diesel)) at 15% and 20% by volume, respectively, referred to as D85P15, D80P20, D85A15, and D80A20, while the effects of the addition of two new oxygenated biomass fuels on the performance of diesel engine and diesel oxidation catalyst (DOC) and catalytic diesel particulate filter (CDPF) after-treatment system were experimentally investigated. Results show that the addition of oxygenated biomass fuels can improve combustion and reduce carbon monoxide (CO) and soot emissions. At heavy load conditions, when D80P20 was used, compared with D100 and D80A20, the conversion efficiency of CO emissions in DOC + CDPF system is always the highest, close to 100%. It shows that the addition of oxygenated biomass fuels can effectively improve the exhaust oxygen concentration. Besides, there is nearly no increase in CDPF pressure drop at each tested engine speed when D80P20 is used. This has greatly improved in CDPF performance.
Numerical Simulation Investigation on Foamy Oil Behavior for a System of Heavy Oil-Mixture Solvent in Porous Media
Authors: Lu Xinqian , Lin Zeyu , Zhou Xiang , Zeng Fanhua 
Published: December 2020

Abstract
Heavy oil resources, as a non-renewable energy resource, often require extra enhanced oil recovery techniques such as solvent-based processes. Many kinds of solvents including pure and mixed solvents have been tested in solvent-based applications. Compared with pure solvent, the solvent mixture has the advantage of relatively higher dew point pressure while maintaining desirable solubility in heavy oil. The characterization of foamy oil behavior in a pure solvent system is different from that of the solvent mixture system despite their similarities. Thus, an additional numerical simulation study is necessary for the solvent mixture system. This work conducted simulation studies to investigate foamy oil behavior in a heavy oil-mixture solvent (C1 + C3) system from pressure depletion tests. A better understanding of foamy oil characterization and mechanism in a heavy oil-mixture solvent system is obtained. A reliable non-equilibrium model is developed to perform simulation studies. Since previous experiments suggest the behavior of foamy oil in the solvent mixture system share similarities with the heavy oil-methane system, this investigation first conducted a simulation study with consideration of two reactions in the model and achieved good agreements between the simulated calculation results and experimentally measurement. Then, four reactions are considered in the model for simulation study and obtained better history match results. The simulation results suggest methane has more impact on the foamy oil behaviors than propane in the heavy oil-mixture solvent system. This work also discussed the effect of model parameters involved in the history matching process and conducted sensitivity analysis.
Enhancements of the Thermal Uniformity Inside a Gas Turbine Dilution Section Using Dimensional Optmization
Authors: Elgammal Tarek , Selim Osama M. , Amano Ryoichi S. 
Published: December 2020

Abstract
In the dilution section of the gas turbine, the flow and thermal mixing between the cold radial jets and hot mainstream is always a matter of interest to generate a consistent thermal profile, extending the longevity of the turbine blades. Multiple researches explored the topic experimentally and numerically, and new designs have been evaluated, including a central streamlined body with swirlers inside the dilution zone. Moreover, the dimensional aspects (diameter, length, and position) of the streamlined body can help in generating more uniform thermal profiles, but with the cost of increased pressure drop. Various design iterations are needed to be tested and assessed based on minimizing the contradicting uniformity number and pressure drop. Such a process is time and resources consuming if not wisely managed. The paper proposes a solution for the current problem by the integration of the “Design of Experiment/Optimization Algorithms” generator with the computational fluid dynamics solver. The outcomes from three different algorithms (ULH, MOGA-II, and HYBRID) are statistically analyzed to understand inputs-outputs correlations, develop response surface methodology, and help in finding the optimal designs. The suggested HYBRID optimization provided a better optimal curve with improvements of 69% and 15% in the thermal uniformity and pressure drop, respectively. The correlation coefficients stressed on the importance of the diameter as the highest influencer with inverse and direct correlations with uniformity and pressure drop, respectively. Finally, the Kriging response surface model enabled more optimal designs and a better understanding of the effective ranges of the three inputs.
Efficient Removal of Magnetic Contamination From Drilling Fluids: The Effect on Directional Drilling
Authors: Saasen Arild , Poedjono Benny , Ånesbug Geir Olav , Zachman Nicholas 
Published: December 2020

Abstract
Magnetic debris in a drilling fluid have a significant influence on the ability of the drilling fluid to maintain its function. Down hole logging can suffer from poor signal to noise ratios. Directional drilling in areas close to the magnetic North Pole, such as in the Barents Sea, Northern Canada, or Russia, can suffer because of magnetic contamination in the drilling fluid. Magnetic particles in the drilling fluid introduce additional errors to the magnetic surveying compared to those normally included in the ellipsoid of uncertainty calculation. On many offshore drilling rigs, there are mounted ditch magnets to remove metallic swarf from the drilling fluid. These magnets normally only remove the coarser swarf. In this project, we use a combination of strong magnets and flow directors to significantly improve the performance of the ditch magnets. This combination, together with proper routines for cleaning the ditch magnets, significantly helps to clean the drilling fluid. Through the combined use of flow directors and ditch magnets, it was possible to extract more than five times as much magnetic contamination from the drilling fluid as normal compared with other proper ditch magnet systems. This is verified by comparing the ditch magnet efficiencies from two drilling rigs drilling extended reach drilling (ERD) wells in the North Sea area. In this paper, it is discussed how the accuracy of directional drilling and well position effected by various interferences can be improved by the use of a drilling fluid with minimal effect to the measurement while drilling (MWD) measurement.
Detection of Unusual Thermal Activities in a Semiconductor Chip Using Backside Infrared Thermal Imaging
Authors: Salvi Swapnil S. , Jain Ankur 
Published: December 2020

Abstract
Rapid detection of hardware Trojans on a semiconductor chip that may run malicious processes on the chip is a critical and ongoing security need. Several approaches have been investigated in the past for hardware Trojan detection, mostly based on changes in circuit parameters due to Trojan activity. Chip temperature is one such parameter that is closely related to the degree of Trojan activity. This paper carries out backside infrared (IR) imaging of a two-die three-dimensional integrated circuit (3D IC) thermal test chip in order to detect unusual thermal activities on the chip. Four distinct image processing algorithms are evaluated and compared in terms of speed, accuracy, and occurrence of false positives and negatives. The impact of background thermal activity and finite duration of Trojan activity on the accuracy of detection is investigated. Within the parameter space tested in this work, the histogram method is found to be the most effective at Trojan detection in the 3D IC. Modifications in data analysis techniques are proposed that improve Trojan detection performance. This work may help develop thermal imaging as a means for real-time Trojan detection and enhancement of security of modern semiconductor chips, including 3D ICs.
Evaluation of a Turbulent Jet Flame Flashback Correlation Applied to Annular Flow Configurations With and Without Swirl
Authors: Sullivan Lewis E. , McDonell Vincent G. , Kalantari Alireza , Saxena Priyank 
Published: December 2020

Abstract
The adaptation of high hydrogen content fuels for low emissions gas turbines represents a potential opportunity to reduce the carbon footprint of these devices. The high flame speed of hydrogen air mixtures combined with the small quenching distances poses a challenge for using these fuels in situations where a significant premixing is desired. In particular, flashback in either the core flow or along the walls (i.e., boundary layer flashback) can be exacerbated with high hydrogen content fuels. In this work, the ability of a flashback correlation previously developed for round jet flames is evaluated for its ability to predict flashback in an annular flow. As a first step, an annular flow is generated with a centerbody located at the centerline of the original round jet flame. Next, various levels of axial swirl is added to that annular flow. Additional flashback data are obtained for various mixtures of hydrogen and methane and hydrogen and carbon monoxide for all the annular flow configurations. Pressures from 3 to 8 bar are tested with mixture temperatures up to 750 K. Flashback is induced by slowly increasing the equivalence ratio. The results obtained show that the same form of the correlation developed for round jet flames can be used to correlate flashback behavior for the annular flow case with and without swirl despite the presence of the centerbody. Adjustments to some of the constants in the original model were made to obtain the best fit, but in general, the correlation is quite similar to that developed for the round jet flame. A significant difference with the annular flow configurations is the determination of the appropriate gradient at the wall, which in the present case is determined using a cold flow computational fluid dynamics simulation.
Longitudinal increases in childhood depression symptoms during the COVID-19 lockdown
Authors: Bignardi Giacomo , Dalmaijer Edwin S , Anwyl-Irvine Alexander L , Smith Tess A , Siugzdaite Roma , Uh Stepheni , Astle Duncan E 
Published: December 2020

ObjectiveThere has been widespread concern that so-called lockdown measures, including social distancing and school closures, could negatively impact children’s mental health. However, there has been little direct evidence of any association due to the paucity of longitudinal studies reporting mental health before and during the lockdown. This present study provides the first longitudinal examination of changes in childhood mental health, a key component of an urgently needed evidence base that can inform policy and practice surrounding the continuing response to the COVID-19 pandemic.MethodsMental health assessments on 168 children (aged 7.6–11.6 years) were taken before and during the UK lockdown (April–June 2020). Assessments included self-reports, caregiver reports, and teacher reports. Mean mental health scores before and during the UK lockdown were compared using mixed linear models.ResultsA significant increase in depression symptoms during the UK lockdown was observed, as measured by the Revised Child Anxiety and Depression Scale (RCADS) short form. CIs suggest a medium-to-large effect size. There were no significant changes in the RCADS anxiety subscale and Strengths and Difficulties Questionnaire emotional problems subscale.ConclusionsDuring the UK lockdown, children’s depression symptoms have increased substantially, relative to before lockdown. The scale of this effect has direct relevance for the continuation of different elements of lockdown policy, such as complete or partial school closures. This early evidence for the direct impact of lockdown must now be combined with larger scale epidemiological studies that establish which children are most at risk and tracks their future recovery.