bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maintaining intravenous volume mitigates hypothermia‐induced myocardial dysfunction and accumulation of intracellular Ca2+
Authors: Nilsen Jan Harald , Schanche Torstein , Kondratiev Timofei V. , Hevrøy Olav , Sieck Gary C. , Tveita Torkjel 
Published: March 2021

New Findings

What is the central question of this study?
Detailed guidelines for volume replacement to counteract hypothermia‐induced intravascular fluid loss are lacking. Evidence suggests colloids might have beneficial effects compared to crystalloids. Are central haemodynamic function and level of hypothermia‐induced calcium overload, as a marker of cardiac injury, restored by fluid substitution during rewarming, and are colloids favourable to crystalloids?

What is the main finding and its importance?
Infusion with crystalloid or dextran during rewarming abolished post‐hypothermic cardiac dysfunction, and partially mitigated myocardial calcium overload. The effects of volume replacement to support haemodynamic function are comparable to those using potent cardio‐active drugs. These findings underline the importance of applying intravascular volume replacement to maintain euvolaemia during rewarming.

AbstractPrevious research exploring pathophysiological mechanisms underlying circulatory collapse after rewarming victims of severe accidental hypothermia has documented post‐hypothermic cardiac dysfunction and hypothermia‐induced elevation of intracellular Ca2+ concentration ([Ca2+]i) in myocardial cells. The aim of the present study was to examine if maintaining euvolaemia during rewarming mitigates cardiac dysfunction and/or normalizes elevated myocardial [Ca2+]i. A total of 21 male Wistar rats (300 g) were surface cooled to 15°C, then maintained at 15°C for 4 h, and subsequently rewarmed to 37°C. The rats were randomly assigned to one of three groups: (1) non‐intervention control (n = 7), (2) dextran treated (i.v. 12 ml/kg dextran 70; n = 7), or (3) crystalloid treated (24 ml/kg 0.9% i.v. saline; n = 7). Infusions occurred during the first 30 min of rewarming. Arterial blood pressure, stroke volume (SV), cardiac output (CO), contractility (dP/dtmax) and blood gas changes were measured. Post‐hypothermic changes in [Ca2+]i were measured using the method of radiolabelled Ca2+ (45Ca2+). Untreated controls displayed post‐hypothermic cardiac dysfunction with significantly reduced CO, SV and dP/dtmax. In contrast, rats receiving crystalloid or dextran treatment showed a return to pre‐hypothermic control levels of CO and SV after rewarming, with the dextran group displaying significantly better amelioration of post‐hypothermic cardiac dysfunction than the crystalloid group. Compared to the post‐hypothermic increase in myocardial [Ca2+]i in non‐treated controls, [Ca2+]i values with crystalloid and dextran did not increase to the same extent after rewarming. Volume replacement with crystalloid or dextran during rewarming abolishes post‐hypothermic cardiac dysfunction, and partially mitigates the hypothermia‐induced elevation of [Ca2+]i.
Comparison of Posterior Fixation Strategies for Thoracolumbar Burst Fracture: A Finite Element Study
Authors: Wong Chia-En , Hu Hsuan-Teh , Tsai Cho-Hsuan , Li Jun-Liang , Hsieh Chin-Chiang , Huang Kuo-Yuan 
Published: March 2021

Abstract
The management of thoracolumbar (TL) burst fractures remained challenging. Due to the complex nature of the fractured vertebrae and the lack of clinical and biomechanical evidence, currently, there was still no guideline to select the optimal posterior fixation strategy for TL burst fracture. We utilized a T10-L3 TL finite element model to simulate L1 burst fracture and four surgical constructs with one- or two-level suprajacent and infrajacent instrumentation (U1L1, U1L2, U2L1, and U2L2). This study was aimed to compare the biomechanical properties and find an optimal fixation strategy for TL burst fracture in order to minimize motion in the fractured level without exerting significant burden in the construct. Our result showed that two-level infrajacent fixation (U1L2 and U2L2) resulted in greater global motion reduction ranging from 66.0 to 87.3% compared to 32.0 to 47.3% in one-level infrajacent fixation (U1L1 and U2L1). Flexion produced the largest pathological motion in the fractured level but the differences between the constructs were small, all within 0.26 deg. Comparisons in implant stress showed that U2L1 and U2L2 had an average 25.3 and 24.8% less von Mises stress in the pedicle screws compared to U1L1 and U1L2, respectively. The construct of U2L1 had better preservation of the physiological spinal motion while providing sufficient range of motion reduction at the fractured level. We suggested that U2L1 is a good alternative to the standard long-segment fixation with better preservation of physiological motion and without an increased risk of implant failure.
Intervertebral Disc Mechanics With Nucleotomy: Differences Between Simple and Dual Loading
Authors: Yang Bo , Klineberg Eric , O'Connell Grace D. 
Published: March 2021

Abstract
Painful herniated discs are treated surgically by removing extruded nucleus pulposus (NP) material (nucleotomy). NP removal through enzymatic digestion is also commonly performed to initiate degenerative changes to study potential biological repair strategies. Experimental and computational studies have shown a decrease in disc stiffness with nucleotomy under single loading modalities, such as compression-only or bending-only loading. However, studies that apply more physiologically relevant loading conditions, such as compression in combination with bending or torsion, have shown contradicting results. We used a previously validated bone–disc–bone finite element model (Control) to create a Nucleotomy model to evaluate the effect of dual loading conditions (compression with torsion or bending) on intradiscal deformations. While disc joint stiffness decreased with nucleotomy under single loading conditions, as commonly reported in the literature, dual loading resulted in an increase in bending stiffness. More specifically, dual loading resulted in a 40% increase in bending stiffness under flexion and extension and a 25% increase in stiffness under lateral bending. The increase in bending stiffness was due to an increase and shift in compressive stress, where peak stresses migrated from the NP–annulus interface to the outer annulus. In contrast, the decrease in torsional stiffness was due to greater fiber reorientation during compression. In general, large radial strains were observed with nucleotomy, suggesting an increased risk for delamination or degenerative remodeling. In conclusion, the effect of nucleotomy on disc mechanics depends on the type and complexity of applied loads.
Non-Newtonian Blood Modeling in Intracranial Aneurysm Hemodynamics: Impact on the Wall Shear Stress and Oscillatory Shear Index Metrics for Ruptured and Unruptured Cases
Authors: Oliveira Iago L. , Santos Gabriel B. , Gasche José L. , Militzer Julio , Baccin Carlos E. 
Published: March 2021

Abstract
When simulating blood flow in intracranial aneurysms (IAs), the Newtonian model seems to be ubiquitous. However, analyzing the results from the few studies on this subject, the doubt remains on whether it is necessary to use non-Newtonian models in computational fluid dynamics (CFD) simulations of cerebral vascular flows. The objective of this study is to investigate whether different rheology models would influence the hemodynamic parameters related to the wall shear stress (WSS) for ruptured and unruptured IA cases, especially because ruptured aneurysms normally have morphological features, such as lobular regions and blebs, that could trigger non-Newtonian phenomena in the blood flow due to low shear rates. Using CFD in an open-source framework, we simulated four ruptured and four unruptured patient-specific aneurysms to assess the influence of the blood modeling on the main hemodynamic variables associated with aneurysm formation, growth, and rupture. Results for WSS and oscillatory shear index (OSI) and their metrics were obtained using Casson and Carreau–Yasuda non-Newtonian models and were compared with those obtained using the Newtonian model. We found that all differences between non-Newtonian and the Newtonian models were consistent among all cases irrespective of their rupture status. We further found that the WSS at peak systole is overestimated by more than 50% by using the non-Newtonian models, but its metrics based on time and surface averaged values are less affected—the maximum relative difference among the cases is 7% for the Casson model. On the other hand, the surface-averaged OSI is underestimated by more than 30% by the non-Newtonian models. These results suggest that it is recommended to investigate different blood rheology models in IAs simulations when specific parameters to characterize the flow are needed, such as peak-systole WSS and OSI.
Physics-Informed Neural Networks for Heat Transfer Problems
Authors: Cai Shengze , Wang Zhicheng , Wang Sifan , Perdikaris Paris , Karniadakis George Em 
Published: March 2021

Abstract
Physics-informed neural networks (PINNs) have gained popularity across different engineering fields due to their effectiveness in solving realistic problems with noisy data and often partially missing physics. In PINNs, automatic differentiation is leveraged to evaluate differential operators without discretization errors, and a multitask learning problem is defined in order to simultaneously fit observed data while respecting the underlying governing laws of physics. Here, we present applications of PINNs to various prototype heat transfer problems, targeting in particular realistic conditions not readily tackled with traditional computational methods. To this end, we first consider forced and mixed convection with unknown thermal boundary conditions on the heated surfaces and aim to obtain the temperature and velocity fields everywhere in the domain, including the boundaries, given some sparse temperature measurements. We also consider the prototype Stefan problem for two-phase flow, aiming to infer the moving interface, the velocity and temperature fields everywhere as well as the different conductivities of a solid and a liquid phase, given a few temperature measurements inside the domain. Finally, we present some realistic industrial applications related to power electronics to highlight the practicality of PINNs as well as the effective use of neural networks in solving general heat transfer problems of industrial complexity. Taken together, the results presented herein demonstrate that PINNs not only can solve ill-posed problems, which are beyond the reach of traditional computational methods, but they can also bridge the gap between computational and experimental heat transfer.
Thermal Transport in Polymers: A Review
Authors: Wei Xingfei , Wang Zhi , Tian Zhiting , Luo Tengfei 
Published: March 2021

Abstract
In this article, we review thermal transport in polymers with different morphologies from aligned fibers to bulk amorphous states. We survey early and recent efforts in engineering polymers with high thermal conductivity by fabricating polymers with large-scale molecular alignments. The experimentally realized extremely high thermal conductivity of polymer nanofibers is highlighted, and understanding of thermal transport physics is discussed. We then transition to the discussion of bulk amorphous polymers with an emphasis on the physics of thermal transport and its relation with the conformation of molecular chains in polymers. We also discuss the current understanding of how the chemistry of polymers would influence thermal transport in amorphous polymers and some limited, but important chemistry-structure-property relationships. Lastly, challenges, perspectives, and outlook of this field are presented. We hope this review will inspire more fundamental and applied research in the polymer thermal transport field to advance scientific understanding and engineering applications.
Homogeneous and Automated Cooling of a Mold Segment by Multiple Water Jet Impingement and a Cross Air Flow
Authors: Agyeman Emmanuel K. K. , Mousseau Pierre , Sarda Alain , Edelin Denis , Lecointe Damien 
Published: March 2021

AbstractMultiple water jets and a cross air flow are used to cool a mold segment in a homogeneous and automated manner. The test segment was cooled from an initial temperature of 573 K. An average temperature difference of less than 3 K and a maximum temperature difference of less than 6 K were obtained along the length of the surface of the test segment during the entire duration of the cooling process as opposed to the traditional channel cooling approach where the mean and maximum temperature differences increase over time. The top surface of the test segment represents the mold/part interface which is of interest in this study. Using model predictive control (MPC) and a data-driven predictive model, the cooling speed of the test segment’s top surface was able to be maintained within ±5 K of the cooling ramp imposed. The results were compared to the results obtained when using a simpler On/Off algorithm for automated cooling. Compared to the simpler On/Off algorithm, there was an improvement in the accuracy of the cooling ramp with respect to its reference value of over 30% for most cooling ramps tested (5–25 K/min). A parametric study on the influence of the flowrates of the fluids on the cooling speed of the test segment’s surface was also conducted.
Closure to “Computational Analysis for Mixed Convective Flows of Viscous Fluids With Nanoparticles” (Farooq, U., Lu, D. C., Ahmed, S., and Ramzan, M., 2019, ASME J. Therm. Sci. Eng. Appl., 11(2), p. 021013)
Authors: Cui Jifeng , Farooq Umer , Razzaq Raheela , Khan Waseem Asghar , Yousif Mogtaba Ahmed 
Published: March 2021

Abstract
The authors regret in the published paper referenced above and agree with the discussion by Pantokratoras (2019, “Discussion: “Computational Analysis for Mixed Convective Flows of Viscous Fluids With Nanoparticles” (Farooq, U., Lu, D. C., Ahmed, S., and Ramzan, M., 2019, ASME J. Therm. Sci. Eng. Appl., 11(2), p. 021013),” ASME J. Therm. Sci. Eng. Appl., 11(5), p. 055503). In this Closure, the non-similar mathematical model is developed to describe the mixed convective nanofluid flow over vertical sheet which is stretching at an exponential rate. In the published article referenced above, similarity transformations are utilized to convert the governing nonlinear partial differential equations (PDEs) into ordinary differential equations (ODEs). The important physical numbers such as magnetic field (M2), Brownian motion parameter (Nb), thermophoresis (Nt), Eckert number (Ec), ratio of mass transfer Grashof to heat transfer Grashof (N), buoyancy parameter (λ), and Reynolds number (Re) appearing in the dimensionless ODEs are still functions of coordinate “x”; therefore, the problem is non-similar. In this corrigendum, the non-similar model is developed by using ξ(x) as non-similarity variable and η(x, y) as pseudo-similarity variable. The dimensionless non-similar model is numerically simulated by employing local non-similarity via bvp4c. The graphical results show no change in behavior. The important thermal and mass transport quantities such as Nusselt number and Sherwood number have been computed for the non-similar model, and results are compared with the published article.
Measurement and Evaluation of the Stiffness Characteristics of Precision Spring Tubes in Hydraulic Servovalves
Authors: Zhang Fuli , Yuan Zhaohui 
Published: March 2021

Abstract
The spring tube is the core component of the hydraulic servovalve, and its stiffness characteristics determine the sensitivity of the servovalve. For the difficulty in measuring and ensuring the stiffness of spring tube in complex structures, based on the principle of structural characteristics and stiffness measurement, an effective method for measuring and evaluating the stiffness of spring tube was proposed. First, by the force analysis of the spring tube in the valve structure, using improved stiffness measurement theory, an equivalent measurement model of single-arm is established. Second, the stiffness measurement system of the spring tube is constructed based on this model. Furthermore, using the deformation and the spatial position recurrence method, the accuracy of the measurement system is further improved. Thirdly, using the orthogonal test method and linear optimization method of the neural network model, the stiffness characteristics of the spring tube under the influence of different factors are studied further. Finally, the validity of the models is verified by using the software comsol and the experimental platform. The stability of the effective stiffness for the spring tube is further analyzed by the measurement data. The contribution and novelty of this paper are that based on the force analysis of the spring tube in the servovalve internal structure, an effective and systematic stiffness measurement and evaluation method are proposed. On this basis, experiments and stiffness characteristics analysis are carried out. Furthermore, several structural factors affecting the stiffness characteristics of spring tube are considered, and the stiffness characteristics of spring tube are systematically studied and analyzed. Based on this research and analysis, the systematic study of measurement and characteristics of precision components is very important for practical complex systems in this field. This makes it possible to further study the measurement of precision components which are difficult to measure in the actual structure. It is instructive to study the characteristics of precision components in complex structures.
An Intelligent Predictive Controller for Power and Battery Management in Plug-In Hybrid Electric Vehicles
Authors: Hassanzadeh Mojtaba , Rahmani Zahra 
Published: March 2021

Abstract
This paper presents a novel real-time energy management strategy (EMS) for plug-in hybrid electric vehicles (PHEVs), which combines the adaptive neuro-fuzzy inference system (ANFIS) and the model predictive control (MPC). A two-objective EMS with two state variables is defined by integrating the battery aging and fuel economy in the objective function. First, the dynamic programming (DP) approach is applied offline to obtain the globally optimal solutions. Then, a real-time predictive EMS is proposed, in which DP carries out a moving-horizon optimization. Contrary to the charge-sustaining HEVs, the optimal trajectory of the battery state-of-charge (SOC) in PHEVs does not fluctuate around a constant level. Thus, determining the desired value of SOC for the real-time moving-horizon optimization is a challenging issue. Unlike the EMSs with a pre-determined reference for SOC, a trained ANFIS model constructs the real-time sub-optimal SOC trajectory in advance. Finally, the effectiveness of the proposed approach is shown through simulation. The proposed EMS is examined over multiple real-time driving cycles, and the results indicate that the total cost is increased compared to those unaware of battery aging. The real-time EMS is then compared to different approaches. While suboptimal, the proposed EMS is real-time implementable, and the results are found to be close enough to those of optimal controller, compared to the two other tested approaches.
Structural styles, deformation, and uplift of the Olympic Mountains, Washington: Implications for accretionary wedge deformation
Authors: Aldrich M. James 
Published: March 2021

Abstract
The Olympic subduction complex is the exposed subaerial Cascadia accretionary wedge in the Olympic Mountains of Washington State. Uplift of the mountains has been attributed to two competing models: margin-normal deformation from frontal accretion and underplating, and margin-parallel deformation from the clockwise rotation and northward movement of the Oregon Coast Range block compressing the Olympic Mountains block against the Canadian Coast Range. East-northeast–oriented folds and Quaternary thrust faults and paleostress analysis of faults in the Coastal Olympic subduction complex, west of the subduction complex massif, provide new evidence for north-south shortening in the Coastal Olympic subduction complex that fills a large spatial gap in the north-south shortening documented in prior studies, substantially strengthening the block rotation model. These new data, together with previous studies that document north-south shortening in the subduction complex and at numerous locations in the Coast Range terrane peripheral to the complex, indicate that margin-parallel deformation of the Cascadia forearc has contributed significantly to uplift of the Olympic Mountains. Coastal Olympic subduction complex shallow-level fold structural style and deformation mechanisms provide a template for analyzing folding processes in other accretionary wedges.
Similar-shaped folds in shallow-level Miocene turbidite sediments of the Coastal Olympic subduction complex formed in two shortening phases not previously recognized in accretionary wedges. Folds began forming by bed-parallel flow of sediment into developing hinges. When the strata could no longer accommodate shortening by flexural flow, further shortening was taken up by flexural slip. Similar-shaped folds in the deeper accretionary wedge rocks of the subduction complex massif have a well-developed axial-surface cleavage that facilitated shear folding with sediment moving parallel to the axial surface into the hinges, a structural style that is common to accretionary wedges. The pressure-temperature conditions and depth at which the formation of similar folds transitions from bed-parallel to axial-surface–parallel deformation are bracketed.
Post-COVID-19 paediatric inflammatory multisystem syndrome: association of ethnicity, key worker and socioeconomic status with risk and severity
Authors: Broad Jonathan , Forman Julia , Brighouse James , Sobande Adebola , McIntosh Alysha , Watterson Claire , Boot Elizabeth , Montgomery Felicity , Gilmour Iona , Tan Joy , Fogarty Mary Johanna , Gomez Xabier , Cheung Ronny , Lillie Jon , Shivamurthy Vinay , Handforth Jenny , Miller Owen 
Published: March 2021

ObjectivesPatients from ethnic minority groups and key workers are over-represented among adults hospitalised or dying from COVID-19. In this population-based retrospective cohort, we describe the association of ethnicity, socioeconomic and family key worker status with incidence and severity of Paediatric Inflammatory Multisystem Syndrome Temporally associated with SARS-CoV-2 (PIMS-TS).SettingEvelina London Children’s Hospital (ELCH), the tertiary paediatric hospital for the South Thames Retrieval Service (STRS) region.Participants70 children with PIMS-TS admitted 14 February 2020–2 June 2020.Outcome measuresIncidence and crude ORs are presented, comparing ethnicity and socioeconomic status of our cohort and the catchment population, using census data and Index of Multiple Deprivation (IMD). Regression is used to estimate the association of ethnicity and IMD with admission duration and requirement for intensive care, inotropes and ventilation.ResultsIncidence was significantly higher in children from black (25.0 cases per 100 000 population), Asian (6.4/100 000) and other (17.8/100 000) ethnic groups, compared with 1.6/100 000 in white ethnic groups (ORs 15.7, 4.0 and 11.2, respectively). Incidence was higher in the three most deprived quintiles compared with the least deprived quintile (eg, 8.1/100 000 in quintile 1 vs 1.6/100 000 in quintile 5, OR 5.2). Proportions of families with key workers (50%) exceeded catchment proportions. Admission length of stay was 38% longer in children from black ethnic groups than white (95% CI 4% to 82%; median 8 days vs 6 days). 9/10 children requiring ventilation were from black ethnic groups.ConclusionsChildren in ethnic minority groups, living in more deprived areas and in key worker families are over-represented. Children in black ethnic groups had longer admissions; ethnicity may be associated with ventilation requirement.This project was registered with the ELCH audit and service evaluation team, ref. no 11186.