bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonuniform Stress Field Determination Based on Deformation Measurement
Authors: Liu C. 
Published: March 2021

Abstract
In this investigation, we demonstrate a technique that, under certain circumstances, will determine stresses associated with a nonuniform deformation field without knowing the detailed constitutive behavior of the deforming material. This technique is based on (1) a detailed deformation measurement of a domain (currently in 2D) and (2) the observation that for isotropic materials, the strain and the stress, which form the so-called work-conjugate pair, are co-axial, or their eigenvectors share the same directions. The particular measures for strain and stress chosen in this study are the Lagrangian (or Green-Lagrangian) strain and the second Piola–Kirchhoff stress. The deformation measurement provides the field of the principal stretch orientation θλ and since the Lagrangian strain and the second Piola–Kirchhoff stress are co-axial, the principal stress orientation θs of the second Piola–Kirchhoff stress is then determined. The Cauchy stress is related to the second Piola–Kirchhoff stress through the deformation gradient tensor, which can be measured experimentally. We then show that the principal stress orientation θσ of the Cauchy stress is the sum of the principal stretch orientation θλ and the local rigid-body rotation θq, which is determinable by the deformation gradient through polar decomposition. Such a relationship is valid for finite deformations. With the principal stress orientation θσ known, the equation of equilibrium, now in terms of the two principal stresses, σ1 and σ2, and θσ, can be solved numerically with appropriate traction boundary conditions. The stresses determined using this technique obviously satisfy the equation of equilibrium, in contrast to those obtained from a constitutive model with input from deformation measurement. The technique and the associated numerical scheme are verified and validated through two virtual test cases representative of the simply-connected and multiply-connected domains, where exact solutions are available. The technique is then applied to an experimental case of nonuniform deformation of a polyvinyl chloride (PVC) sheet with a circular hole and subject to uniaxial tension. In this case, the associated stress field is also determined through a constitutive model of hyperelasticity, the generalized neo-Hookean (GNH) model, calibrated for the particular PVC sheet. Limitations and restrictions of the technique and the associated numerical scheme, as well as possible extensions will be discussed.
Design of the Magnetic Stamp Film for Electromagnetic-Assisted Transfer Printing
Authors: Yu Qingmin , Li Anran , Yu Xudong , Zhou Honglei , Cheng Huanyu 
Published: March 2021

AbstractAs a critical step to integrate micro-nano electronic components on the soft substrate, transfer printing allows the facile fabrication of flexible electronics. The key to a successful transfer printing process is to modulate the interfacial adhesion strength at the stamp/device interface. As an advanced approach, electromagnetic-assisted transfer printing explores a sealed chamber with a magnetic stamp film at the bottom that can be reversibly actuated by the externally applied magnetic field. The deflected magnetic stamp film changes the pressure inside the chamber to modulate the interfacial adhesion at the stamp/device interface. Here, we investigate various design considerations and demonstrate a magnetic stamp film with magnetic NdFeB particles dispersed in a silicone polymer. A theoretical model is first established to study the reversible upward (or downward) deformation of the magnetic stamp film in a positive (or negative) magnetic field. The theoretical model reveals the effects of the mass fraction of the magnetic particles, the thickness of the magnetic film, and the magnetic field intensity on the deformation of the film and the transfer printing process. The theoretically predicted linear relationship between the maximum displacement of the magnetic film and the applied magnetic field is validated by finite element analysisand experimental results.
Molten Pool Tracking Using a Superpixel-Based Approach in a Laser Metal Deposition Process
Authors: García-Moreno Angel-Iván , Alvarado-Orozco Juan-Manuel , Ibarra-Medina Juansethi , Martínez-Franco Enrique 
Published: March 2021

AbstractNowadays, additive manufacturing technologies (AM) suffer from insufficient or lacking methodologies/techniques for quality control. This fact represents a key technological barrier preventing broader industrial adoption of AM, particularly in high-value applications where component failure cannot be accepted. This article presents a real-time melt pool segmentation and monitoring technique applicable to the direct laser metal deposition (LMD) process. An infrared camera with an InSb detector (resolution of 640 × 480, spectral range between 3 and 5 μm) was used. An algorithm, called gravitational superpixels, is presented. This algorithm can group pixels and generate superpixels based on a block generation technique that compares color similarity and temperature in infrared images. Besides, a color similarity correction is applied to reduce uncertainty in segmentation, as well as for eliminating the image background. The task of extracting edges is based on the law of universal gravitation. A quantitative and qualitative algorithm performance analysis, which uses standard metrics, is presented. The analysis demonstrates better versatility than reduction/feature extraction or image segmentation approaches by high-/low-pass filtering. The experimental validation was carried out, extracting and measuring the molten pool geometry and its thermal signature. Then, measures were compared against ground truth and against results obtained by other similar methods. The proposed gravitational superpixel method has higher precision and performance. Our proposal has a significant potential for monitoring industrial AM processes since it requires minimal modifications of commercially available industrial machines.
Research on Deformation Mechanism of Cutting Nickel-Based Superalloy Inconel718 Based on Strain Gradient Theory
Authors: Hao ZhaoPeng , Li JiNing , Fan YiHang 
Published: March 2021

Abstract
The traditional material constitutive model can effectively simulate the mechanical properties during the cutting process. However, the scale characteristics contained in materials are not considered in the traditional cutting model, and the inherent scale effect of materials is also ignored. Therefore, the traditional cutting constitutive model cannot effectively reflect the size effect in the cutting process, and then cannot obtain the accurate stress, strain, and temperature. In this present paper, a material constitutive model which can reflect the scale effect is established based on the strain gradient plasticity theory. Through the established model and secondary development of abaqus, the two-dimensional dynamic finite element simulation model of cutting Inconel 718 is established. By comparing the cutting experiment results with the simulation results, the established simulation model can more accurately reflect the effects of temperature, strain gradient effect, equivalent stress, and its scale effect on cutting deformation during the machining process.
Reliability of telemedicine for real-time paediatric ophthalmology consultations
Authors: Stewart Carly , Coffey-Sandoval Josephine , Reid Mark W , Ho Tiffany C , Lee Thomas C , Nallasamy Sudha 
Published: March 2021

Background/aimsTo assess the accuracy of real-time telemedicine to diagnose and manage paediatric eye conditions.MethodsDesign: Prospective, non-inferiority study analysing agreement in diagnoses and management plans between telemedicine and in-person examinations. Setting: Paediatric ophthalmology clinic. Population: Children 0–17 years, English-speaking or Spanish-speaking, able to participate in age-appropriate manner, either previously seen by the optometrist and required ophthalmology referral or newly referred from outside source. Procedures: Paediatric optometrist conducted examinations using digital equipment and streamed live to a paediatric ophthalmologist who recorded diagnoses and management plans, then re-examined patients in-person. Subjects were masked to the fact they would see the ophthalmologist in-person, same-day. Main outcome measures: Discrepancy in management plan or diagnosis between telemedicine and in-person examinations. Non-inferiority threshold was <1.5% for management plan or <15% for diagnosis discrepancies.Results210 patients participated in 348 examinations. 131 (62.4%) had strabismus as primary diagnosis. In these patients, excellent and almost perfect agreement was observed for angle measurements (intraclass correlation coefficients=0.98–1.00) and disease categorisation (kappa=0.94–1.00) (p<0.0001 in all cases). No primary diagnoses changed, and no management plans changed following in-person examination. 54/55 patients who consented for surgery at the initial visit did so while masked to receiving an in-person examination. Families felt comfortable with the quality of the telemedicine examination (98.5%) and would participate in another in the future (97.1%).ConclusionPaediatric ophthalmic conditions can be reliably diagnosed and managed via telemedicine. Access for underserved populations may be improved by collaboration between ophthalmologists and optometrists using this technology.
Hormonal contraceptive use, bone density and biochemical markers of bone metabolism in British Army recruits
Authors: Coombs Charlotte V , O'Leary T J , Tang J C Y , Fraser W D , Greeves J P 
Published: March 2021

IntroductionHormonal contraceptive use might impair bone health and increase the risk of stress fracture by decreasing endogenous oestrogen production, a central regulator of bone metabolism. This cross-sectional study investigated bone density and biochemical markers of bone metabolism in women taking hormonal contraceptives on entry to basic military training.MethodsForty-five female British Army recruits had biochemical markers of bone metabolism, areal bone mineral density (aBMD) and tibial speed of sound (tSOS) measured at the start of basic military training. Participants were compared by their method of hormonal contraception: no hormonal contraception (NONE), combined contraceptive pill (CP) or depot-medroxyprogesterone acetate (DMPA) (20±2.8 years, 1.64±0.63 m, 61.7±6.2 kg).ResultsaBMD was not different between groups (p≥0.204), but tSOS was higher in NONE (3%, p=0.014) when compared with DMPA users. Beta C-terminal telopeptide was higher in NONE (45%, p=0.037) and DMPA users (90%, p=0.003) compared with CP users. Procollagen type 1 N-terminal propeptide was higher in DMPA users compared with NONE (43%, p=0.045) and CP users (127%, p=0.001), and higher in NONE compared with CP users (59%, p=0.014). Bone alkaline phosphatase was higher in DMPA users compared with CP users (56%, p=0.044).ConclusionsDMPA use was associated with increased bone turnover and decreased cortical bone integrity of the tibia. Lower cortical bone integrity in DMPA users was possibly mediated by increased intracortical remodelling, but trabecular bone was not affected by contraceptive use.
A First-line management team’s strategies for sustaining resilience in a specialised intensive care unit—a qualitative observational study
Authors: Hybinette Karl , Pukk Härenstam Karin , Ekstedt Mirjam 
Published: March 2021

ObjectivesAcute care units manage high risk patients at the edge of scientifically established treatments and organisational constraints while aiming to balance reliability to standards with the needs of situational adaptation (resilience). First-line managers are central in coordinating clinical care. Any systemic brittleness will be evident only in retrospect through, for example, care quality measures and accident statistics. This challenges us to understand what successful managerial strategies for adaptation are and how they could be improved. The managerial work of balancing reliability and adaptation is only partially understood. This study aims to explore and describe how system resilience is enhanced by naturally occurring coordination performed in situ by a management team under variable circumstances.DesignAn explorative observational study of a tertiary neonatal intensive care unit (NICU) in Sweden. One year of broad preparatory work followed by focused shadowing observations of coordination analysed through inductive–deductive content analysis from a perspective of resilience engineering.ParticipantsA team of managers (ie, clinical coordinators, head nurses, senior medical doctors).ResultsThe results describe a functional relationship between operational stress and a progression of adjustments in the actual situation, expressed through recurring patterns of adaptation. Managers focused on maintaining coherence in escalating problematic situations by facilitating teamwork through goalsetting, problem-solving and circumventing the technical systems’ limitations.ConclusionsCoordination supports a coherent goal setting by increased team collaboration and is supported by team members’ abilities to predict the behaviour of each other. Our findings suggest that in design of future research or training for coordination, the focus of assessment and reflection on adaptive managerial responses may lie on situations where the system was ‘stretched’ or ‘needed reorganisation’ and that learning should be about whether the actions were able to achieve short-term goals while preserving the long-term goals.
Direct transfer to angiosuite for patients with severe acute stroke treated with thrombectomy: the multicentre randomised controlled DIRECT ANGIO trial protocol
Authors: Riou-Comte Nolwenn , Zhu François , Cherifi Aboubaker , Richard Sébastien , Nace Lionel , Audibert Gérard , Achit Hamza , Costalat Vincent , Arquizan Caroline , Beaufils Olivier , Consoli Arturo , Lapergue Bertrand , Loeb Thomas , Rouchaud Aymeric , Macian Francisco , Cailloce Dominique , Biondi Alessandra , Moulin Thierry , Desmettre Thibaut , Marnat Gaultier , Sibon Igor , Combes Xavier , Lebedinsky Ariel Pablo , Vuillemet Francis , Kempf Nicolas , Pierot Laurent , Moulin Solene , Lemmel Philippe , Mazighi Mikael , Blanc Raphael , Sabben Candice , Schluck Eric , Bracard Serge , Anxionnat René , Guillemin Francis , Hossu Gabriela , Gory Benjamin 
Published: March 2021

IntroductionMechanical thrombectomy (MT) increases functional independence in patients with acute ischaemic stroke with anterior circulation large vessel occlusion (LVO), and the probability to achieve functional independence decreases by 20% for each 1-hour delay to reperfusion. Therefore, we aim to investigate whether direct angiosuite transfer (DAT) is superior to standard imaging/emergency department-based management in achieving 90-day functional independence in patients presenting with an acute severe neurological deficit likely due to LVO and requiring emergent treatment with MT.Methods and analysisDIRECT ANGIO (Effect of DIRECT transfer to ANGIOsuite on functional outcome in patient with severe acute stroke treated with thrombectomy: the randomised DIRECT ANGIO Trial) trial is an investigator-initiated, multicentre, prospective, randomised, open-label, blinded endpoint (PROBE) study. Eligibility requires a patient ≤75 years, pre-stroke modified Rankin Scale (mRS) 0–2, presenting an acute severe neurological deficit and admitted within 5 hours of symptoms onset in an endovascular-capable centre. A total of 208 patients are randomly allocated in a 1:1 ratio to DAT or standard management. The primary outcome is the rate of patients achieving a functional independence, assessed as mRS 0–2 at 90 days. Secondary endpoints include patients presenting confirmed LVO, patients eligible to intravenous thrombolysis alone, patients with intracerebral haemorrhage and stroke-mimics, intrahospital time metrics, early neurological improvement (reduction in National Institutes of Health Stroke Scale by ≥8 points or reaching 0–1 at 24 hours) and mRS overall distribution at 90 days and 12 months. Safety outcomes are death and intracerebral haemorrhage transformation. Medico-economics analyses include health-related quality of life and cost utility assessment.Ethics and disseminationThe DIRECT ANGIO trial was approved by the ethics committee of Ile de France 1. Study began in April 2020. Results will be published in an international peer-reviewed medical journal.Trial registration numberNCT03969511.
Predictive value of Modified Early Warning Score (MEWS) and Revised Trauma Score (RTS) for the short-term prognosis of emergency trauma patients: a retrospective study
Authors: Yu Zhejun , Xu Feng , Chen Du 
Published: March 2021

ObjectivesThis study aimed to assess the predictive value of the Modified Early Warning Score (MEWS) and Revised Trauma Score (RTS) for emergency trauma patients who died within 24 hours.DesignA retrospective, single-centred study.SettingThis study was conducted at a tertiary hospital in Southern China.ParticipantsA total of 1739 patients with acute trauma, aged 16 years or older who presented to the emergency department from 1 November 2016 to 30 November 2019, were included.Interventions noneNone.Outcome24-hour mortality was the primary outcome of trauma.Results1739 patients were divided into the survival group (1709 patients,98.27%), and the non-survival group (30 patients,1.73%). Crude OR and adjusted OR of MEWS were 1.99, 95% CI (1.73 to 2.29), and 2.00, 95% CI (1.74 to 2.31), p<0.001, respectively. Crude OR and adjusted OR of RTS were 0.62, 95% CI (0.55 to 0.69) and 0.61, 95% CI (0.55 to 0.68), p<0.001, respectively. The area under the curve of MEWS was significantly higher than that of RTS (p=0.005): 0.927, 95% CI (0.914 to 0.939) vs 0.799, 95% CI (0.779 to 0.817).ConclusionsBoth MEWS and RTS were independent predictors of the short-term prognosis in emergency trauma patients, MEWS had better predictive efficacy.
Effect of free distribution of medicines on the process of care for adult patients with type 1 and type 2 diabetes and hypertension: post hoc analysis of randomised controlled trial findings
Authors: Charles Onella , Woods Hannah , Ally Muhamad , Manns Braden , Shah Baiju R , Wang Ri , Persaud Nav 
Published: March 2021

ObjectivesThe Carefully Selected and Easily Accessible at No charge Medicines randomised controlled trial showed that patients receiving free access to medicines had improved diabetes and hypertension outcomes compared with patients who had usual access to medicines. In this study, we aimed to test the impact of providing free access to medicine to people with diabetes and hypertension on process of care indicators.DesignIn this post hoc analysis of randomised controlled trial findings, we identified process of care indicators for the management of diabetes and hypertension using relevant guidelines. The following process of care indicators were identified for diabetes management: encounters with healthcare professionals, blood pressure measurements, self-monitoring of blood glucose, annual eye and foot examination, annual administration of the influenza vaccine, and laboratory testing for glycated haemoglobin (HbA1c), low-density lipoprotein-cholesterol, serum creatinine and urine albumin to creatinine ratio. We identified the following process of care indicators for hypertension: encounters with healthcare professionals, blood pressure measurements, self-measuring of blood pressure, and serum tests for electrolytes, HbA1c, lipids and creatinine. Chart extractions were performed for all patients and the indicators for diabetes and hypertension were recorded. We compared the indicators for patients in each arm of the trial.ResultsThe study included 268 primary care patients. Free distribution of medicines may improve self-monitoring behaviours (adjusted rate ratio (aRR) 1.30; 95% CI 0.66 to 2.57) and reduce missed primary care appointments for patients with diabetes (aRR 0.80; 95% CI 0.48 to 1.33) or hypertension (aRR 0.41; 95% CI 0.18 to 0.90). Free distribution may also reduce primary care and consultant appointments and laboratory testing in patients with hypertension.ConclusionsImproving medicine accessibility for patients with diabetes and hypertension not only improves surrogate health outcomes but also improves the patient experience and may also reduce healthcare costs by encouraging self-monitoring.Trial registration numberThe randomised controlled trial mentioned is clinicaltrials.gov identifier: NCT02744963.
Socioeconomic inequalities and adverse pregnancy outcomes in the UK and Republic of Ireland: a systematic review and meta-analysis
Authors: Thomson Katie , Moffat Malcolm , Arisa Oluwatomi , Jesurasa Amrita , Richmond Catherine , Odeniyi Adefisayo , Bambra Clare , Rankin Judith , Brown Heather , Bishop Julie , Wing Susan , McNaughton Amy , Heslehurst Nicola 
Published: March 2021

ObjectiveThere has been an unprecedented rise in infant mortality associated with deprivation in recent years in the United Kingdom (UK) and Republic of Ireland. A healthy pregnancy can have significant impacts on the life chances of children. The objective of this review was to understand the association between individual-level and household-level measures of socioeconomic status and adverse pregnancy outcomes.DesignSystematic review and meta-analysis.Data sourcesNine databases were searched (Medline, Embase, Scopus, ASSIA, CINAHL, PsycINFO, BNI, MIDRIS and Google Scholar) for articles published between 1999 and August 2019. Grey literature searches were also assessed.Study selection criteriaStudies reporting associations between individual-level or household socioeconomic factors on pregnancy outcomes in the UK or Ireland.ResultsAmong the 82 353 search results, 53 821 titles were identified and 35 unique studies met the eligibility criteria. Outcomes reported were neonatal, perinatal and maternal mortality, preterm birth, birth weight and mode of delivery. Pooled effect sizes were calculated using random-effects meta-analysis. There were significantly increased odds of women from lower levels of occupation/social classes compared with the highest level having stillbirth (OR 1.40, 95% CI 1.23 to 1.59, I298.62%), neonatal mortality (OR 1.39, 95% CI 1.22 to 1.57, I297.09%), perinatal mortality (OR 1.39, 95% CI 1.23 to 1.57, I298.69%), preterm birth (OR 1.41, 95% CI 1.33 to 1.50, I270.97%) and low birth weight (OR 1.40, 95% CI 1.19 to 1.61, I299.85%). Limitations relate to available data, unmeasured confounders and the small number of studies for some outcomes.ConclusionsThis review identified consistent evidence that lower occupational status, especially manual occupations and unemployment, were significantly associated with increased risk of multiple adverse pregnancy outcomes. Strategies to improve pregnancy outcomes should incorporate approaches that address wider determinants of health to provide women and families with the best chances of having a healthy pregnancy and baby and to decrease pregnancy-related health inequalities in the general population.PROSPERO registration numberPROSPERO CRD42019140893.