bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Three-Dimensional Finite Element Damage Mechanics Model to Simulate Fretting Wear of Hertzian Line and Circular Contacts in Partial Slip Regime
Authors: Ahmadi Arman , Sadeghi Farshid 
Published: July 2021

Abstract
In this investigation, a three-dimensional (3D) finite element model (FEM) was developed to study fretting wear of Hertzian circular and line contacts. The wear law incorporated in this model is based on the accumulated dissipated energy (ADE). A stress-based damage mechanics finite element model using the ADE was developed to determine wear of non-conformal bodies in contact. Voronoi tessellation was used to simulate the microstructure of the materials during the fretting process. In order to simulate the wear area in fretting contacts, a material removal approach was developed and implemented in the model. The FEM was used to investigate partial slip regimes under various operating conditions. The normal and shear surface tractions for the circular and line contacts were applied to the domain in order to improve the computational efficiency. The calculated wear volume rate using the FE model is in good agreement with the wear coefficient available in the open literature. The influence of modulus of elasticity, hardness, and coefficient of friction on the partial slip fretting phenomenon were studied. In order to verify the model, several fretting wear tests were conducted using AISI 8620 steel and AISI 1566 steel in a partial slip regime of circular contact configuration. The properties for each material such as the modulus of elasticity, hardness, and the grain size were measured experimentally and compared with the model. For the defined load and displacement amplitude of the experimental fretting tests, both materials have shown a partial slip behavior in the initial cycles and then transition to a gross slip regime. The numerical model predicted the worn surface and wear-rate in partial slip regime which corroborated well with these experimental test results.
On the Evolution of Passive Magnetic Bearings
Authors: Samanta P. , Hirani H. 
Published: July 2021

Abstract
The present work portrays the latest review of the progressive advances in passive magnetic bearing (PMB) technology. PMB is an old technology with many encouraging properties. However, there are a number of inherent issues with design, analysis, and performance characterization that must be considered for reliable operation. Finally, it examines in detail the geometrical configurations, load-bearing capacity, dynamic behavior, and stability connected with stiffness and damping.
Temporal changes in blood pressure following prehospital rapid sequence intubation
Authors: Fouche Pieter Francsois , Meadley Ben , StClair Toby , Winnall Alison , Stein Christopher , Jennings Paul Andrew , Bernard Stephen , Smith Karen 
Published: July 2021

BackgroundRapid Sequence intubation (RSI) is an airway procedure that uses sedative and paralytic drugs to facilitate endotracheal intubation. It is known that RSI could impact blood pressure in the peri-intubation period. However, little is known about blood pressure changes in longer time frames. Therefore, this analysis aims to describe the changes in systolic blood pressure in a large cohort of paramedic-led RSI cases over the whole prehospital timespan.MethodsIntensive Care Paramedics in Victoria, Australia, are authorised to use RSI in medical or trauma patients with a Glasgow Coma Scale <10. This retrospective cohort study analysed data from patientcare records for patients aged 12 years and above that had received RSI, from 1 January 2008 to 31 December 2019. This study quantifies the systolic blood pressure changes using regression with fractional polynomial terms. The analysis is further stratified by high versus Low Shock Index (LSI). The shock index is calculated by dividing pulse rate by systolic blood pressure.ResultsDuring the study period RSI was used in 8613 patients. The median number of blood pressure measurements was 5 (IQR 3–8). Systolic blood pressure rose significantly by 3.4 mm Hg (p<0.001) and then returned to baseline in the first 5 min after intubation for LSI cases. No initial rise in blood pressure is apparent in High Shock Index (HSI) cases. Across the whole cohort, systolic blood pressure decreased by 7.1 mm Hg (95% CI 7.9 to 6.3 mm Hg; p<0.001) from the first to the last blood pressure measured.ConclusionsOur study shows that in RSI patients a small transient elevation in systolic blood pressure in the immediate postintubation period is found in LSI, but this elevation is not apparent in HSI. Blood pressure decreased over the prehospital phase in RSI patients with LSI, but increased for HSI cases.
#3112 Acquired aphantasia in 88 cases: a preliminary report
Authors: Knowles Laurence , Jones Kealan , Zeman Adam 
Published: July 2021

AimsFor most of us, visual imagery is a fundamental feature of day-to-day subjective experience. It is thought to play multiple cognitive roles.1 However, there is widespread variation in the subjective intensity of visual imagery, ranging from extreme vividness to complete absence. The term aphantasia was coined recently to describe the latter, which is usually lifelong. While rarer, cases of acquired aphantasia can provide mechanistic insight. Isolated cases have long been reported,2 with some attempts at theoretical synthesis.3 4 We give a preliminary description of 88 such cases identified from among ~14,000 people contacting us in the wake of publicity surrounding Aphantasia.MethodsCases were selected from individuals contacting us spontaneously reporting reduced or absent intensity of visual imagery. Contacts were asked to complete two measures of visual imagery, the Vividness of Visual Imagery Questionnaire (VVIQ) and Imagery Questionnaire (IQ).5ResultsCases were divided into those in with a strong probability of a neurological cause (n=39), a psychological cause (n=20) and those about which we cannot yet be confident (n=29). Functional aphantasia appears likely to account for some of the cases in the third category. The commonest precipitating events were head injury (n=19), affective disorder (n=17) and stroke (n=13). Other causes included surgery (postoperative) (n=7), drugs (n=6), infectious or inflammatory disease (n=3), neurodegenerative disease (n=3), and seizure disorders (n=2). For subjects completing the VVIQ (n=29), the mean score was 20.1/80 (range 16-32,) indicating marked reduction of imagery vividness. Localizable lesions were predominantly right sided (n=6) and occurred in posterior cortical areas, particularly occipital and parietal, as well as two cases associated with damage to temporal cortex. Some cases reported other impairments, including impaired memory (n=12), prosopagnosia (n=5) and navigational difficulties (n=2). Of cases who reported on their dreams (n=28), around half had lost visual dreaming, a third had preserved visual dreaming and the remainder had visual dreaming of reduced intensity.ConclusionsTo our knowledge, this is the largest reported case series of acquired loss of visual imagery. Both neurological and psychological disorders can be responsible for acquired aphantasia. Our series includes cases of probable functional aphantasia. Further detailed analysis of these cases is required.References Pearson. Nat. Rev. Neurosci. 2019;20:624634. Zago, et al. Cognit. Neuropsychiatry 2011;16:481504. Farah. Cognition 1984;18:245272. Bartolomeo. Cortex 2002;38:357378. Zeman, et al. Cortex 2020;130:426440.
#3029 HIV-associated neurocognitive disorder: an investigation using structural neuroimaging in a c-ART treated tanzanian cohort
Authors: McDonald Lucy , Koipapi Sengua , Howlett William , Dekker Marieke , Urasa Sarah , Kalaria Rajesh , Walker Richard , Firbank Michael , Paddick Stella-Maria 
Published: July 2021

BackgroundThere is a newly emergent ageing population of people living with HIV (PLWH) in Africa. However, there is little research into HIV-associated neurocognitive disorder (HAND) in this population. Existing research suggests HAND is prevalent however the aetiology remains unclear. This study aims to determine whether HAND is truly prevalent and explore potential causes in PLWH on c-ART using objective structural measures.AimsExplore whether substantial atrophy and/or white matter hyperintensities (WMH) is present on the clinical magnetic resonance imaging (MRI) reports and quantitative analysis of people with optimally managed HIV in Northern Tanzania.Explore the aetiology of HAND by assessing whether cerebral atrophy and/or WMH is associated with demographic risk factors, HIV–related factors and/or comorbidities.Investigate whether structural damage is related to objectively measured cognitive impairment, and whether this is a subcortical or cortical impairment.Explore which neurocognitive test is the best predictor of structural damage and therefore most valid diagnostic test for HAND.MethodsA systematic sample of PLWH aged ≥ 50 were recruited from a HIV clinic in Kilimanjaro, Tanzania. Demographic data and comorbidities were self-reported. HIV-disease management data were obtained. Viral load and CD4 count were measured. A neurocognitive battery and informant history of functional impairment identified HAND. Cerebral atrophy (brain and ventricle volume) and WMH were measured using quantitative analysis of 1.5T MRI.Preliminary resultsThis cohort (n=91) had well-managed HIV (75.9% suppressed viral load, median CD4 507 cells/ul). The significant independent predictor (IP) of decreased brain volume was older age at HIV diagnosis (p=.001), and of increased ventricle volume was increased age (p<.0001), male gender (p<.0001) and increased frailty (p<.0001). The significant IPs of increased WMH volume were increased age (p<.0001) and smoking (p=.021). Only memory impairment independently predicted all structural measures.ConclusionsThis is the first MRI study of older c-ART treated PLWH in Africa. Despite c-ART and good disease management, HAND was objectively prevalent and unrelated to measures of HIV. Cerebral atrophy and WMH were associated with factors of neurodegeneration. Cerebral atrophy was associated with male gender and age at diagnosis (legacy effect).
#3090 Different measures of behavioural involvement in amyotrophic lateral sclerosis yield varying rates of behavioural change
Authors: Didcote Lyndsay , Vitoratou Silia , Al-Chalabi Ammar , Goldstein Laura H 
Published: July 2021

Objectives/AimsAmyotrophic Lateral Sclerosis (ALS), also known as Motor Neuron Disease (MND), is a progressive and life-limiting neurodegenerative disease which can involve behavioural change. There are five commonly reported disease-specific screening tools of behavioural change but it is not clear how they differ in applicability. This study therefore set out to investigate the extent to which these measures similarly identify impairment by examining i) intercorrelations between scores on the measures completed about the same people with ALS, and ii) the percentage of people with ALS characterised as impaired on each measure.MethodsThe behavioural component of the ALS-Cognitive Behavioural Screen (ALS-CBS-b), behavioural component of the Edinburgh Cognitive and Behavioural ALS Screen (ECAS-b), ALS-Frontotemporal Dementia Questionnaire (ALS-FTD-Q), Beaumont Behavioural Inventory (BBI), and MND Behavioural Instrument (MiND-B) were all completed by 35 carers of people with ALS. Total scores for each measure underwent Spearman correlation analysis. Classifications of impairment (for behavioural impairment or ALS-FTD) were determined using published cut-offs and agreement between measures was determined by calculating Cohens kappa coefficients.ResultsThe behavioural measures were significantly intercorrelated (p<0.05 in all cases) but with differing strengths of association. The association between the ALS-CBS-b and ALS-FTD-Q was weak to moderate (r=0.41) while other associations between the ALS-FTD-Q, MiND-B, BBI, and ALS-CBS-b were moderate to strong (0.53-0.75). While the ECAS-b was moderately associated with the BBI (r=0.53), the ECAS-b was only weakly to moderately associated with the ALS-CBS-b, MiND-B and ALS-FTD-Q (0.36-0.48). The association between ALS-CBS-b and ALS-FTD-Q scores (r=0.41) was similarly in the weak to moderate range. The ECAS-b and ALS-CBS-b had the weakest intercorrelation (r=0.36). Percentages of the sample classified with behavioural involvement by the measures ranged between 20.0% (ALS-FTD-Q) and 74.3% (MiND-B). Percentages of the sample classified with ALS-FTD by the measures ranged between 2.9% (ECAS-b) and 20% (ALS-CBS-b). Agreement of classification between measures (Cohens kappa) was mostly fair to moderate (0.21-0.57) although generally better for classifications of ALS-FTD than for milder behavioural involvement. Between the ECAS-b and BBI there was complete agreement on the classification of ALS-FTD (k = 1.0).ConclusionsExisting measures of behavioural change in people with ALS may yield very differing conclusions and cannot be assumed to be interchangeable. Variability in the detection of impairment between measures may result from differing item content, behaviours sampled or cut-off scores for impairment. This inconsistency between measures may lead to inappropriate healthcare provision and discrepancies in research conclusions.FundingMND Association
#3106 Limb weakness in the emergency department: a focus on unexplained aetiology presentations
Authors: Wang Qiying , Udom Arina , Wang Yanxin , Kusnierz-Was Paulina , Castro Megan , Butler Matthew , Posporelis Sotirios 
Published: July 2021

BackgroundFunctional neurological disorder (FND) is a common and potentially disabling neuropsychiatric condition. While its presentation can be extremely diverse, from aphonia to seizure activity, one of the most common symptoms is weakness of one or more limbs. Despite functional weakness being one of the most common presentations seen in neurological practice, little is known about its prevalence in an Emergency Department (ED) setting. Hereby, we aim to describe the demographic and clinical characteristics of patients attending the ED with limb weakness of an unknown and potentially functional aetiology.MethodsWe carried out a retrospective electronic records review of all ED attendances with limb weakness as the presenting complaint, at Kings College Hospital. Patients admitted to the hospital were followed up until the point of discharge. The following clinical and demographic data were analyzed: age, gender, mode of arrival, psychiatric history and clinical diagnosis on discharge. Results: During the 15-month study period, 1340 patients presented with leg weakness at the ED, nearly half of these (47.54%) arrived by ambulance. 4.55% had unexplained weakness with no definite diagnosis on discharge. A significant proportion (62.31%) were admitted for further investigations; 6.35% of these were diagnosed with FND, while a further 25 patients (2.99%) were discharged with suspected FND. Patients with an FND diagnosis had a median age of 45 years; 62.96% were females, and they were significantly younger than male patients with FND (P=0.003). Less than half (44%) of the FND patients had one or more psychiatric diagnoses.DiscussionA diagnosis of functional leg weakness was given to 3.95% (53/1340) of patients presenting with leg weakness in the ED. It is striking that none of these patients were given a diagnosis of FND in the ED, but only after admission to a ward. 6.4% (86/1340) were discharged from the hospital with an unclear diagnosis, 14% of which a functional overlay was suspected. Main limitations of the study: it is retrospective and single-centre.ConclusionThis study highlights difficulties and obstacles in recognising and diagnosing functional presentations of limb weakness in the ED. There is a clear need for optimisation of the classification and coding system of the Emergency Department. Increased awareness and education around FND has the potential to raise diagnostic confidence and significantly improve patient experience and care.
#3123 Assessing international alcohol and internet use patterns during COVID-19 isolation using an online survey: highlighting distinct stressors conferring risk to compulsive behaviours
Authors: Sallie Samantha N , Ritou Valentin JE , Bowden-Jones Henrietta , Voon Valerie 
Published: July 2021

Objectives and AimsThe Coronavirus (COVID-19) pandemic has required drastic safety measures to contain virus spread, including an extended self-isolation period. Those with greater perceived or actual life stress are vulnerable to develop or reinstate problematic behaviours characterised by addiction and compulsive mechanisms. Thus, we assessed how the COVID-19 pandemic and isolation measures affected alcohol consumption and internet use in the general population.MethodsWe developed an online international survey, entitled Habit Tracker (HabiT), completed by 1,346 adults (≥18 years), which measured changes in amount and severity of alcohol consumption (Alcohol Use Disorders Identification Test; AUDIT),online gaming (Internet Gaming Disorder Scale-Short Form; IGDS9-SF), and pornography viewing (Cyber Pornography Addiction Test; CYPAT) before (post-hoc recall)and during the COVID-19 pandemic and consequent lockdown. These measures were related to ten COVID-19-specific stress factors. Lastly, we assessed psychiatric factors widely recognized to be associated with problematic alcohol and internet use such as anxiety, depression (Hospital Anxiety and Depression Scale; HADS), and impulsivity (Short Impulsive-Behavior Scale; SUPPS-P).ResultsOf the sample, we observed an overall increase in online gaming and a decrease alcohol consumption and pornography viewing. Those who increased their amount and severity of alcohol use (36%) during lockdown reported stress associated with the pandemic itself, such as being an essential worker directly caring for those with or having a loved one become severely ill from COVID-19. Further, those residing in the United Kingdom- as opposed the United States or Canada- increased their weekly amount of alcohol consumption. Alternatively, those who increased online gaming (64%) and pornography viewing (43%)reported low frequency or poor quality social interactions resultant of lockdown measures. All three groups displayed higher levels of depression, anxiety, and urgency impulsivity.ConclusionsOur findings underscore the theoretical mechanism of negative emotionality underlying forms of compulsive behaviour driven by stress, depression, and anxiety; while highlighting distinct avenues by which these behaviours can manifest. Limitations include subjects being within varying phases of lockdown during the time of testing and a large degree of study dropout (n=1,515). We emphasise the relevance of identifying those in need of greater support services to mitigate negative health outcomes associated with problematic alcohol consumption and internet usage in the context of COVID-19 isolation.
7 Covid-19 and neuropsychiatry
Authors: Michael Benedict D 
Published: July 2021

As the clinical features and potential complications of COVID-19 emerged last year it became clear that neurological, neuropsychiatric and psychiatric disorders were potentially significant. There were also reasons to expect this from past viral outbreaks, including other severe coronaviruses. The CoroNerve study, led by Ben Michael and colleagues, was rapidly set up to as a UK-wide surveillance system for clinicians to initially briefly notify cases and later provide full clinical details. A psychiatry reporting system, led by the RCPsych neuropsychiatry faculty, was added and the first 153 notifications were published last June. The full clinical details of the first 267 cases completed were published as a preprint in January.The has been a rapid growth in the number and quality of publications regarding the neuropsychiatry of COVID-19 and this has been collated on the JNNP Neurology & Neuropsychiatry of COVID-19 blog which we set up to respond to the need for rapid capture and synthesis of a fast moving field with weekly updates and publications from a growing international team, including a recently published preprint systematic review and meta-analysis of the neurology and neuropsychiatry of COVID-19. We will jointly review the CoroNerve data and its context in the emerging wider evidence base regarding the neuropsychiatry of COVID-19, highlighting exciting new research areas such as long COVID and projects such as the recently started COVID-CNS study funded by UKRI.We would like to thank those who have already submitted cases to CoroNerve and encourage others to do the same, including those associated with COVID-19 vaccination, and to flag up that notifying a case and providing data results in pubmed searchable collaborator status on resulting publications.
Peripheral blood leucocyte telomere length is associated with progression of interstitial lung disease in systemic sclerosis
Authors: Liu Shuo , Chung Melody P , Ley Brett , French Sarah , Elicker Brett M , Fiorentino David F , Chung Lorinda S , Boin Francesco , Wolters Paul J 
Published: July 2021

BackgroundPeripheral blood leucocyte telomere length (PBL-TL) is associated with outcomes in patients with idiopathic pulmonary fibrosis. Whether PBL-TL is associated with progression of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is unknown.MethodsA retrospective observational cohort study was performed using prospectively collected data from 213 patients with SSc followed at the University of California San Francisco (UCSF) Scleroderma Center. PBL-TL was measured by quantitative PCR of DNA isolated from peripheral blood. Associations between PBL-TL and pulmonary function test trends in patients with SSc-ILD were assessed by longitudinal analysis using Generalised Linear Mixed Models. Findings were validated in a cohort of 61 patients with SSc-ILD enrolled in the Stanford University Scleroderma Center database.ResultsPatients with UCSF SSc with ILD were found to have shorter PBL-TL compared with those without ILD (6554±671 base pairs (bp) vs 6782±698 bp, p=0.01). Shorter PBL-TL was associated with the presence of ILD (adjusted OR 2.1 per 1000 bp TL decrease, 95% CI [1.25 to 3.70], p=0.006). PBL-TL was shorter in patients with SSc-ILD lacking SSc-specific autoantibodies compared with seropositive subjects (6237±647 bp vs 6651±653 bp, p=0.004). Shorter PBL-TL was associated with increased risk for lung function deterioration with an average of 67 mL greater loss in per year for every 1000 bp decrease in PBL-TL in the combined SSc-ILD cohorts (longitudinal analysis, adjusted model: 95% CI −104 mL to −33 mL, p<0.001).ConclusionsThese findings suggest that telomere dysfunction may be associated with SSc-ILD progression and that PBL-TL measurement may be useful for stratifying risk for SSc-ILD progression.