bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the Thermomechanical Stresses in Double-Wall Effusion Cooled Systems
Authors: Elmukashfi Elsiddig , Murray Alexander V. , Ireland Peter T. , Cocks Alan C. F. 
Published: February 2020

Abstract
In this study, thermal stresses in a double-wall cooling system are analyzed. We consider an infinite flat double-wall geometry and assume that it can be represented by an axisymmetric unit cell, wherein the thermal loadings and deformation at the boundaries are determined by periodicity conditions. A thermal model is initially developed to obtain the thermal fields using a combination of empirical correlations and computational fluid dynamics (CFD) analysis. The thermal fields are then analyzed such that both the first-order and higher order approximations are determined. A theoretical solution is derived assuming that the temperature gradient takes place only across the outer skin using the first-order approximations. The solution yields an equibiaxial stress state in the skins, which are driven by the thermal curvature of the outer skin. To investigate other geometrical features and higher order approximations, a finite element model is used to solve Fourier’s law of heat conduction and mechanical equilibrium equations. The numerical and theoretical results are found to be in excellent agreement. We determine that the increase of distance between pedestals reduces the stresses. Furthermore, the stress concentration factor at the fillet increases with the increase of both the radius and pedestal diameter and the decrease of the skin thickness. Increasing the number of film holes limits stresses to the external surface of the outer skin. The increase of the Reynolds number in the impingement hole increases the Biot number in the outer skin, which increases the stresses. The higher order approximations of the heat transfer coefficients play a minor role.
The Influence of Playing Surface on the Loading Response to Soccer-Specific Activity
Authors: Jones Adam , Page Richard , Brogden Chris , Langley Ben , Greig Matt 
Published: February 2020

Context: The influence of playing surface on injury risk in soccer is contentious, and contemporary technologies permit an in vivo assessment of mechanical loading on the player. Objective: To quantify the influence of playing surface on the PlayerLoad elicited during soccer-specific activity. Design: Repeated measures, field-based design. Setting: Regulation soccer pitches. Participants: Fifteen amateur soccer players (22.1 [2.4] y), injury free with ≥6 years competitive experience. Interventions: Each player completed randomized order trials of a soccer-specific field test on natural turf, astroturf, and third-generation artificial turf. GPS units were located at C7 and the mid-tibia of each leg to measure triaxial acceleration (100 Hz). Main Outcome Measures: Total accumulated PlayerLoad in each movement plane was calculated for each trial. Ratings of perceived exertion and visual analog scales assessing lower-limb muscle soreness were measured as markers of fatigue. Results: Analysis of variance revealed no significant main effect for playing surface on total PlayerLoad (P = .55), distance covered (P = .75), or postexercise measures of ratings of perceived exertion (P = .98) and visual analog scales (P = .61). There was a significant main effect for GPS location (P < .001), with lower total loading elicited at C7 than mid-tibia (P < .001), but with no difference between limbs (P = .70). There was no unit placement × surface interaction (P = .98). There was also a significant main effect for GPS location on the relative planar contributions to loading (P < .001). Relative planar contributions to loading in the anterioposterior:mediolateral:vertical planes was 25:27:48 at C7 and 34:32:34 at mid-tibia. Conclusions: PlayerLoad metrics suggest that playing surface does not influence mechanical loading during soccer-specific activity (not including tackling). Clinical reasoning should consider that PlayerLoad magnitude and axial contributions were sensitive to unit placement, highlighting opportunities in the objective monitoring of load during rehabilitation.
Continuous evolution of oceanic crustal structure following an eruption at Axial Seamount, Juan de Fuca Ridge
Authors: Doran Adrian K. , Crawford Wayne C. 
Published: February 2020

Abstract
We present the first continuous observations of the temporal evolution of oceanic crustal shear velocity beneath Axial Seamount, a submarine volcano on the Juan de Fuca Ridge (offshore northwestern North America). Weekly values of seafloor compliance, the periodic deformation of the seafloor under ocean waves, were estimated over the time period between December 2014 and May 2018 using data from two cabled broadband ocean-bottom seismometers with collocated absolute pressure sensors. We inverted these measurements for shear-wave velocity within the volcano beneath the two stations as a function of depth and time. Our results, combined with estimates of seismic compressional wave velocity, suggest that the shallow melt reservoir and the lower crust beneath the central caldera contain melt fractions of 14% and at least 4%, respectively. The eruption of April 2015 induced a dramatic drop in shear velocities beneath the central station, primarily in the lower crust, which could have been caused by an increase in melt fraction, a change in small-scale melt geometry, or both. The absence of such a change beneath the eastern flank of the caldera indicates that there is a lower-crustal conduit beneath the caldera center, which is much narrower in cross section (&lt;1 km2) than the overlying melt reservoir (≥42 km2). Our study demonstrates the promise of using continuous data to understand submarine volcanism and crustal accretionary processes.
A critical magma chamber size for volcanic eruptions
Authors: Townsend Meredith , Huber Christian 
Published: February 2020

Abstract
We present a model for a coupled magma chamber–dike system to investigate the conditions required to initiate volcanic eruptions and to determine what controls the size of eruptions. The model combines the mechanics of dike propagation with internal chamber dynamics including crystallization, volatile exsolution, and the elastic response of the magma and surrounding crust to pressure changes within the chamber. We find three regimes for dike growth and eruptions: (1) below a critical magma chamber size, eruptions are suppressed because chamber pressure drops to lithostatic before a dike reaches the surface; (2) at an intermediate chamber size, the erupted volume is less than the dike volume (“dike-limited” eruption regime); and (3) above a certain chamber size, dikes can easily reach the surface and the erupted volume follows a classic scaling law, which depends on the attributes of the magma chamber (“chamber-limited” eruption regime). The critical chamber volume for an eruption ranges from ∼0.01 km3 to 10 km3 depending on the water content in the magma, depth of the chamber, and initial overpressure. This implies that the first eruptions at a volcano likely are preceded by a protracted history of magma chamber growth at depth, and that the crust above the magma chamber may have trapped several intrusions or “failed eruptions.” Model results can be combined with field observations of erupted volume, pressure, and crystal and volatile content to provide tighter constraints on parameters such as the eruptible chamber size.
Suboptimal heart rate assessment and airway management in infants receiving delivery room chest compressions: a quality assurance project
Authors: Boldingh Anne Marthe , Skåre Christiane , Nakstad Britt , Solevåg Anne Lee 
Published: February 2020

ObjectiveIn a previous audit, we demonstrated poor compliance with the neonatal resuscitation algorithm. Training can improve guideline compliance and performance. We aimed to prospectively collect detailed data on delivery room resuscitations to identify needs for educational interventions.DesignObservational study using video recordings of neonatal resuscitations. We analysed episodes where chest compressions (CCs) were provided.SettingA Norwegian university hospital.PatientsAll delivery room resuscitations August 2014 to November 2016.InterventionsThe recordings were transcribed using Interact V.9 software (Mangold Int GmbH, Arnstorf, Germany). Supplementary information was collected from the patient electronic records.Main outcome measuresHeart rate (HR) assessment, provision of positive pressure ventilation (PPV) and CC, endotracheal intubation and team communication.ResultsTwenty-nine CC episodes were analysed. We identified team discordance in the decisions to perform CC and only 6 (21%) were retrospectively judged to be in need for CC: 8 (28%) infants had adequate spontaneous respiration, 18 (62%) infants received ineffective PPV and 5 (17%) had a HR >60 bpm. Only one infant was intubated before CC, and we could not identify a consistent pattern of ventilation corrective actions. One infant received CC without prior HR assessment. In some infants, CC duration was exceedingly short, and 11 (38%) of the infants that received CC were not admitted to the NICU. Six (21%) infants had no documentation of CPR in the delivery record.ConclusionsEducation and training should focus on team function and communication, correct and timely HR assessment, effective PPV, and indications for endotracheal intubation.
Priorities for collaborative research using very preterm birth cohorts
Authors: Zeitlin Jennifer , Sentenac Mariane , Morgan Andrei S , Ancel Pierre Yves , Barros Henrique , Cuttini Marina , Draper Elizabeth , Johnson Samantha , Lebeer Jo , Maier Rolf F , Norman Mikael , Varendi Heili 
Published: February 2020

ObjectivesTo develop research priorities on the consequences of very preterm (VPT) birth for the RECAP Preterm platform which brings together data from 23 European VPT birth cohorts.Design and settingThis study used a two-round modified Delphi consensus process. Round 1 was based on 28 research themes related to childhood outcomes (<12 years) derived from consultations with cohort researchers. An external panel of multidisciplinary stakeholders then ranked their top 10 themes and provided comments. In round 2, panel members provided feedback on rankings and on new themes suggested in round 1.ResultsOf 71 individuals contacted, 64 (90%) participated as panel members comprising obstetricians, neonatologists, nurses, general and specialist paediatricians, psychologists, physiotherapists, parents, adults born preterm, policy makers and epidemiologists from 17 countries. All 28 initial themes were ranked in the top 10 by at least six panel members. Highest ranking themes were: education (73% of panel members' top 10 choices); care and outcomes of extremely preterm births, including ethical decisions (63%); growth and nutrition (60%); emotional well-being and social inclusion (55%); parental stress (55%) and impact of social circumstances on outcomes (52%). Highest ranking themes were robust across panel members classified by background. 15 new themes had at least 6 top 10 endorsements in round 2.ConclusionsThis study elicited a broad range of research priorities on the consequences of VPT birth, with good consensus on highest ranks between stakeholder groups. Several highly ranked themes focused on the socioemotional needs of children and parents, which have been less studied.
Introducing pre-exposure prophylaxis to prevent HIV acquisition among men who have sex with men in Sweden: insights from a mathematical pair formation model
Authors: Hansson Disa , Strömdahl Susanne , Leung Ka Yin , Britton Tom 
Published: February 2020

ObjectivesSince 2017, the Public Health Agency of Sweden recommends that pre-exposure prophylaxis (PrEP) for HIV should be offered to high-risk individuals, in particular to men who have sex with men (MSM). The objective of this study is to develop a mathematical model investigating the effect of introducing PrEP to MSM in Sweden.DesignA pair formation model, including steady and casual sex partners, is developed to study the impact of introducing PrEP. Two groups are included in the model: sexually high active MSM and sexually low active MSM. Three mixing assumptions between the groups are considered.SettingA gay-friendly MSM HIV/sexually transmitted infection testing clinic in Stockholm, Sweden. This clinic started offering PrEP to MSM in October 2018.ParticipantsThe model is calibrated according to detailed sexual behaviour data gathered in 2015 among 403 MSM.ResultsBy targeting sexually high active MSM, a PrEP coverage of 3.5% of the MSM population (10% of all high actives) would result in the long-term HIV prevalence to drop considerably (close to 0%). While targeting only low actives would require a PrEP coverage of 35% for a similar reduction. The main effect of PrEP is the reduced susceptibility, whereas the increased HIV testing rate (every third month) among PrEP users plays a lesser role.ConclusionsTo create a multifaceted picture of the effects of interventions against HIV, we need models that include the different stages of HIV infection and real-world data on detailed sexual behaviour to calibrate the mathematical models. Our findings conclude that targeting HIV high-risk individuals, within HIV risk populations such as MSM, with PrEP programmes could greatly decrease the long-term HIV prevalence in Sweden. Therefore, risk stratification of individuals is of importance in PrEP implementation programmes, to ensure optimising the effect and cost-effectiveness of such programmes.
Effect of once weekly folic acid supplementation on erythrocyte folate concentrations in women to determine potential to prevent neural tube defects: a randomised controlled dose-finding trial in Malaysia
Authors: Samson Kaitlyn L I , Loh Su Peng , Khor Geok Lin , Mohd Shariff Zalilah , Yelland Lisa N , Leemaqz Shalem , Makrides Maria , Hutcheon Jennifer A , Sulistyoningrum Dian C , Yu Jessica J , Roche Marion L , De-Regil Luz Maria , Green Tim J , Karakochuk Crystal D 
Published: February 2020

IntroductionFolic acid (0.4 mg) taken prior to and during early pregnancy reduces the risk of neural tube defects (NTDs). Because these birth defects occur early in pregnancy, before women may know they are pregnant, many countries have mandated the addition of folic acid to food staples. In countries where fortification is not possible, and weekly iron folic acid programmes exist to reduce anaemia, the WHO recommends that 2.8 mg (7×0.4 mg) folic acid be given instead of the current weekly practice of 0.4 mg. Currently, there is a lack of evidence to support if the 2.8 mg folic acid per week dose is sufficient to raise erythrocyte folate concentrations to a level associated with a reduced risk of a NTD-affected pregnancy. We aim to conduct a three-arm randomised controlled trial to determine the effect of weekly folic acid with iron on erythrocyte folate, a biomarker of NTD risk.Methods and analysisWe will recruit non-pregnant women (n=300; 18–45 years) from Selangor, Malaysia. Women will be randomised to receive either 2.8, 0.4 or 0.0 (placebo) mg folic acid with 60 mg iron weekly for 16 weeks, followed by a 4-week washout period. The primary outcome will be erythrocyte folate concentration at 16 weeks and the mean concentration will be compared between randomised treatment groups (intention-to-treat) using a linear regression model adjusting for the baseline measure.Ethics and disseminationEthical approval was obtained from the University of British Columbia (H18-00768) and Universiti Putra Malaysia (JKEUPM-2018-255). The results of this trial will be presented at scientific conferences and published in peer-reviewed journals.Trial registration numbersACTRN12619000818134 and NMRR-19-119-45736.
De-implementing wisely: developing the evidence base to reduce low-value care
Authors: Grimshaw Jeremy M , Patey Andrea M , Kirkham Kyle R , Hall Amanda , Dowling Shawn K , Rodondi Nicolas , Ellen Moriah , Kool Tijn , van Dulmen Simone A , Kerr Eve A , Linklater Stefanie , Levinson Wendy , Bhatia R Sacha 
Published: February 2020

Choosing Wisely (CW) campaigns globally have focused attention on the need to reduce low-value care, which can represent up to 30% of the costs of healthcare. Despite early enthusiasm for the CW initiative, few large-scale changes in rates of low-value care have been reported since the launch of these campaigns. Recent commentaries suggest that the focus of the campaign should be on implementation of evidence-based strategies to effectively reduce low-value care. This paper describes the Choosing Wisely De-Implementation Framework (CWDIF), a novel framework that builds on previous work in the field of implementation science and proposes a comprehensive approach to systematically reduce low-value care in both hospital and community settings and advance the science of de-implementation.The CWDIF consists of five phases:Phase 0, identification of potential areas of low-value healthcare;Phase 1, identification of local priorities for implementation of CW recommendations;Phase 2, identification of barriers to implementing CW recommendations and potential interventions to overcome these;Phase 3, rigorous evaluations of CW implementation programmes;Phase 4, spread of effective CW implementation programmes. We provide a worked example of applying the CWDIF to develop and evaluate an implementation programme to reduce unnecessary preoperative testing in healthy patients undergoing low-risk surgeries and to further develop the evidence base to reduce low-value care.
Ten-year trends in the incidence, treatment and outcomes of patients with mitral stenosis in Korea
Authors: Kim Ju Youn , Kim Sung-Hwan , Myong Jun Pyo , Choi Young , Hwang You Mi , Kim Tae-Seok , Kim Ji-Hoon , Jang Sung-Won , Oh Yong-Seog , Lee Man-Young 
Published: February 2020

ObjectiveMitral stenosis increases the risk of atrial fibrillation (AF) and stroke. Large data underlying the trend in incidence, treatment and outcomes of mitral stenosis are lacking.MethodsBased on the Health Insurance Review and Assessment Service database in Republic of Korea, patients who were diagnosed with mitral stenosis between 2007 and 2016 were enrolled. Trends in the incidence rate and changing patterns of treatment and outcome for stroke and systemic embolism and intracranial haemorrhage (ICH) were analysed.ResultsA total of 42 075 patients (mean age 60.7±13.5 years, 13 303 (31.6%) male) were included in the present study. The number included 27 824 (66.1%) patients with mitral stenosis and comorbid AF. The age-standardised annual incidence rate per 100 000 of mitral stenosis in Korea decreased remarkably from 10.3 to 3.6 over 10 years. The use of anticoagulation therapy increased consistently. The annual incidence of stroke and systemic embolism showed signs of plateau, while the incidence of ICH increased.ConclusionsThe overall incidence rate of mitral stenosis in Korean population has decreased remarkably. As increasing the use of vitamin K antagonist, the annual incidence rate of ICH was increased but the rate of stroke incidence reached a plateau. Alternative effective anticoagulation strategy should be investigated.
Serum uric acid is associated with damage in patients with systemic lupus erythematosus
Authors: Elera-Fitzcarrald Claudia , Reátegui-Sokolova Cristina , Gamboa-Cardenas Rocio Violeta , Medina Mariela , Zevallos Francisco , Pimentel-Quiroz Victor Román , Cucho-Venegas Jorge Mariano , Alfaro-Lozano José , Rodriguez-Bellido Zoila , Pastor-Asurza Cesar Augusto , Perich-Campos Risto Alfredo , Alarcón Graciela S , Ugarte-Gil Manuel Francisco 
Published: February 2020

IntroductionSerum uric acid levels have been reported as predictors of cardiovascular, pulmonary, neurological and renal morbidity in patients with SLE. However, their role in cumulative global damage in these patients has not yet been determined.ObjectiveTo determine whether serum uric acid levels are associated with new damage in patients with SLE.MethodsThis is a longitudinal study of patients with SLE from the Almenara Lupus Cohort, which began in 2012. At each visit, demographic and clinical characteristics were evaluated, such as activity (Systemic Lupus Erythematosus Disease Activity Index-2K or SLEDAI-2K) and cumulative damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index or SDI). Treatment (glucocorticoids, immunosuppressive drugs and antimalarials) was also recorded. Univariable and multivariable Cox regression models were used to determine the impact of serum uric acid levels on the risk of new damage.ResultsWe evaluated 237 patients, with a mean age (SD) at diagnosis of 35.9 (13.1) years; 220 patients (92.8%) were women, and the duration of the disease was 7.3 (6.6) years. The mean SLEDAI-2K and SDI scores were 5.1 (4.2) and 0.9 (1.3), respectively. Serum uric acid level was 4.5 (1.4) mg/dL. Follow-up time was 3.1 (1.3) years, and 112 (47.3%) patients accrued damage during follow-up. In univariable and multivariable analyses, serum uric acid levels were associated with new damage (HR=1.141 (95% CI 1.016 to 1.282), p=0.026; HR=1.189 (95% CI 1.025 to 1.378), p=0.022, respectively).ConclusionHigher serum uric acid levels are associated with global damage in patients with SLE.
5-year follow-up of spinal and sacroiliac MRI abnormalities in early axial spondyloarthritis: data from the DESIR cohort
Authors: Madari Queeny , Sepriano Alexandre , Ramiro Sofia , Molto Anna , Claudepierre Pascal , Wendling Daniel , Dougados Maxime , van der Heijde Desirée , van Gaalen Floris A 
Published: February 2020

ObjectiveTo study changes on MRI of the spine and sacroiliac joint (SIJ) in early axial spondyloarthritis (axSpA) over time.MethodsIn the Devenir des Spondyloarthropathies Indifférenciées Récentes cohort, MRI-spine and MRI-SIJ at baseline and 2 and 5 years were scored by central readers for bone marrow oedema (BME), fatty lesions, erosions, sclerosis, ankylosis and spinal bone spurs. The average mean number of lesions was reported or the agreement of ≥2 out of 3 readers for binary outcomes. Net progression was calculated by subtracting the patients that ‘improved’ from those that ‘worsened’ divided by the total number of patients.ResultsOver 5 years, in 155 patients with axSpA (mean age 33.5 (SD 8.9) years, symptom duration 1.4 (0.8) years, 63% human leucocyte antigen+, 14% modified New York+), BME on MRI-SIJ decreased by a mean Spondyloarthritis Research Consortium of Canada score of 1.4 (SD 6.5) (p=0.009). The largest BME decrease was observed in patients using biological disease-modifying antirheumatic drugs at 5 years. Spinal BME increased by 0.3 (4.6) (p=0.41). Fatty lesions and/or erosions on MRI-SIJ increased by a mean of 1.0 (SD 2.6) (p<0.001). Spinal fatty lesions and/or erosions increased by 0.2 (SD 0.5) (p<0.001). Compared with baseline, at 5 years, 7.3% less patients had BME on MRI-SIJ according to the Assessment of Spondyloarthritis International Society definition, while 6.6% more patients had ≥5 fatty lesions and/or erosions. At 5 years, 0.7% less patients had ≥5 spinal BME lesions and 0.7% less patients had ≥5 spinal fatty lesions.ConclusionOver 5 years, BME on MRI-SIJ decreased and spinal BME remained similar, but numerically, little progression of structural lesions on MRI of the SIJ and spine was seen.