bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure of pressure-gradient-driven current singularity in ideal magnetohydrodynamic equilibrium
Authors: Huang Yi-Min , Zhou Yao , Loizu Joaquim , Hudson Stuart , Bhattacharjee Amitava 
Published: January 2023

Abstract
Singular currents typically appear on rational surfaces in non-axisymmetric ideal magnetohydrodynamic (MHD) equilibria with a continuum of nested flux surfaces and a continuous rotational transition. These currents have two components: a surface current (Dirac δ-function in flux surface labeling) that prevents the formation of magnetic islands, and an algebraically divergent Pfirsch–Schlüter current density when a pressure gradient is present across the rational surface. On flux surfaces adjacent to the rational surface, the traditional treatment gives the Pfirsch–Schlüter current density scaling as

J
∼
1

/

Δ
ι

, where

Δ
ι

is the difference of the rotational transform relative to the rational surface. If the distance s between flux surfaces is proportional to

Δ
ι

, the scaling relation

J
∼
1

/

Δ
ι
∼
1

/

s

will lead to a paradox that the Pfirsch–Schlüter current is not integrable. In this work, we investigate this issue by considering the pressure-gradient-driven singular current in the Hahm–Kulsrud–Taylor problem, which is a prototype for singular currents arising from resonant magnetic perturbations. We show that not only the Pfirsch–Schlüter current density but also the diamagnetic current density are divergent as

∼

1

/

Δ
ι

. However, due to the formation of a Dirac δ-function current sheet at the rational surface, the neighboring flux surfaces are strongly packed with

s
∼
(
Δ
ι

)

2

. Consequently, the singular current density

J
∼
1

/

s

, making the total current finite, thus resolving the paradox. Furthermore, the strong packing of flux surfaces causes a steepening of the pressure gradient near the rational surface, with

∇
p
∼

d

p

/

d

s
∼
1

/

s

. In general non-axisymmetric MHD equilibrium, contrary to Grad’s conjecture that the pressure profile is flat around densely distributed rational surfaces, our result suggests a pressure profile that densely steepens around them.
Binding energy produced within the framework of the accretion of millisecond pulsars
Authors: Taani Ali 
Published: January 2023

Abstract
The role and implication of binding energy through the accretion-induced collapse (AIC) of accreting white dwarfs (WDs) for the production of millisecond pulsars (MSPs) are investigated. The binding energy model is examined due to the dynamic process in closed binary systems, and the possible mass of the companion sufficient to induce their orbital parameters is investigated. The deterministic nature of this interaction has a strong sensitivity to the equation of state of the binary systems (where the compactness of a neutron star is proportional to the amount of binding energy) associated with their initial conditions. This behavior mimics the commonly assumed mass and amount of accreted matter under the instantaneous mass loss (

). As a result, this indicates an increase in the MSP's gravitational mass due to angular momentum losses. The outcome of such a system is then a circular binary MSP in which the companion is a low-mass WD, thus distinguishing the binary formation scenarios. In addition, the results of this work could provide constraints on the expected mass and binding energy of a neutron star based on the accretion rate.
Additive manufacturing and performance of bioceramic scaffolds with different hollow strut geometries
Authors: Pang Shumin , Wu Dongwei , Gurlo Aleksander , Kurreck Jens , Hanaor Dorian A H 
Published: January 2023

Abstract
Additively manufactured hollow-strut bioceramic scaffolds present a promising strategy towards enhanced performance in patient-tailored bone tissue engineering. The channels in such scaffolds offer pathways for nutrient and cell transport and facilitate effective osseointegration and vascularization. In this study, we report an approach for the slurry based additive manufacturing of modified diopside bioceramics that enables the production of hollow-strut scaffolds with diverse cross-sectional forms, distinguished by different configurations of channel and strut geometries. The prepared scaffolds exhibit levels of porosity and mechanical strength that are well suited for osteoporotic bone repair. Mechanical characterization in orthogonal orientations revealed that a square outer cross-section for hollow struts in woodpile scaffolds gives rise to levels of compressive strength that are higher than those of conventional solid cylindrical strut scaffolds despite a significantly lower density. Finite element analysis confirms that this improved strength arises from lower stress concentration in such geometries. It was shown that hollow struts in bioceramic scaffolds dramatically increase cell attachment and proliferation, potentially promoting new bone tissue formation within the scaffold channel. This work provides an easily controlled method for the extrusion-based 3D printing of hollow strut scaffolds. We show here how the production of hollow struts with controllable geometry can serve to enhance both the functional and mechanical performance of porous structures, with particular relevance for bone tissue engineering scaffolds.
Effect of laser texturing bulges on tribological properties of 316L stainless steel
Authors: Li Wen-Xuan , Liu Yan , Duan Hai-Tao , Wang Yi-Han , Zhan Sheng-Peng , Zhang Wu-Lin , Yang Tian , Li Guo-Zheng , Dan Jia 
Published: January 2023

Abstract
The laser surface texture process will inevitably produce the edge of material surface texture bulges. Currently, laser processing bulges are generally polished directly, but this method ignores its impact on the friction pairs. In this paper, the tribological properties of polished and unpolished textured surfaces were investigated under dry friction, oil lubrication, and seawater lubrication conditions using three shapes of texture (grooves, square pits, and round pits) prepared on the surface of 316L stainless steel. The results show that the polished surface of 316L stainless steel texture increases wears, and the friction mechanism is mainly adhesive wear, while the unpolished surface of the texture has less wear, and the friction mechanism is mainly abrasive wear. The method and principle of using machining bulges to improve the wear resistance of friction pairs are discussed to address the differences in the tribological performance of entire friction pairs due to the influence of machining bulges of different shapes of texture.
An overview on plasma-assisted thermochemical treatments of martensitic stainless steels
*
Authors: Scheuer Cristiano José , Cardoso Rodrigo Perito , Brunatto Silvio Francisco 
Published: January 2023

Abstract
Demand for higher wear and corrosion resistance components has attracted increasing interest in surface engineering. This line of research develops alternative processes for improving the surface properties of engineering materials. The traditional route seeks the development of new alloys. However, the cost and time associated with these developments become prohibitive in many cases. Currently, the application of plasma-assisted thermochemical treatments has been a technically and economically viable alternative to extend the lifespan of components exposed to severe environments. In this sense, the tooling industry is one of the oldest and most traditional users of plasma-assisted processes, since forming, injection and/or cutting tools are usually subjected to wear and corrosion degradation. Among the various materials used to make tools, we highlight the martensitic stainless steels, which are used in the manufacture of molds and inserts for injection of chlorinated and fluorinated thermoplastic and thermoset polymers. In these applications, martensitic stainless steels are exposed to severe deterioration conditions due to abrasive wear and corrosion by chloride and fluoride ions. Considering the variety of available plasma-assisted thermochemical treatments whose application allows improving metallic materials corrosion and wear resistance, it is a complex task to select the better process and its execution parameters to ensure the maximum performance in operation. In this work, it is proposed a systematic method to aid the process selection task, focused on thermochemical treatments of martensitic stainless steels, which integrates the processing conditions and the resulting microstructure, properties and performance. For this purpose, working envelop for selecting processes and processing parameters were elaborated, that allow qualify and quantify the correlations among each specific plasma-assisted thermochemical treatment (like nitriding, carburizing, nitrocarburizing, etc.) execution conditions, with the resulting properties and performance for treated martensitic stainless steels. In parallel, the genesis of plasma-assisted thermochemical treatments is also described, a bibliometric analysis is carried out on the publications on the subject, and also, a summary description of the surface characteristics of the treated materials is realized.
A combination of experimental and numerical method for optimizing the sensitivity of ultra-thin piezoelectric sensor with interdigitated electrodes
Authors: Laurila Mika-Matti , Montero Karem Lozano , Mäntysalo Matti 
Published: January 2023

Abstract
We report the development of a finite element model (FE-model) for ultra-thin piezoelectric poly(vinylidene-trifluoroethylene) sensor with interdigitated electrodes (IDE) which includes the effect of a non-homogenous poling field determined via the combination of experimental and numerical methods. The non-homogenous poling magnitude is estimated by comparing the remanent polarization (P
r) of IDE based device to the P
r of the same material in metal–insulator–metal electrode configuration. The non-homogenous poling orientation is estimated by comparing the experimentally determined normal mode sensitivity (S
n) values to FE-modelled sensitivity values with different poling orientation distributions. The poling orientation distribution is modelled using two approaches: (a) 33-direction parallel and perpendicular to the electrode plane and (b) 33-direction defined by an average angle. The first approach yields the best correspondence with the experimental results (R
2 = 94.70% and σ = 0.10 pC N−1) and it is used to optimize the device geometry and poling condition for maximum S
n.
1242 CO-MORBIDITY, FRAILTY AND EJECTION FRACTION IN OLDER HEART FAILURE INPATIENTS
Authors: Shah G , Nehikhare I , Obiechina N , Michael A , Gill A , Carey P , Khan R , Slavica M , Khan T , Rahman S , Mushtaq W , Brar H , Senthilselvan S , Mukherjee M , Nandi A 
Published: January 2023

Abstract

Introduction
Co-morbidities and frailty are common in older heart failure patients. The aim of this study is to explore the relationship between co-morbidity, frailty and ejection fraction (EF) in older heart failure inpatients

Methods
A cross-sectional, observational, retrospective analysis of consecutive patients aged 60 years and over who were admitted with heart failure in a UK hospital. Patients with incomplete data were excluded. The Carlson’s comorbidity index (CCI) was used to compute comorbidity and the Rockwood Clinical Frailty Scale (CFS) was used to measure frailty. The EF was calculated as the midpoint of the ranges measured by echocardiography. IBM SPSS 28 software was used for statistical analysis. Descriptive statistics were used to measure baseline characteristics and Pearson’s correlation coefficient and linear regression were used to calculate correlation.

Results and discussion
101 patients were analysed; 48 males and 53 females. Mean age was 81.2 years(SD 9.98). Mean CCI was 6.97(SD 1.63) and mean CFS was 5.09(SD 1.14). There was statistically significant positive correlation between CCI and CFS (r= 0.232; p= .01). There was statistically significant inverse correlation between CCI and EF (r= -.277; p=. 005). When taking into account the level of frailty the correlation between CCI and EF was much stronger in non-frail than in frail patients (r= -.612; p=. 035 and r= -.216; p= .047 respectively). There was no correlation between CFS and EF (r= .095; p=.26). This was not surprising as HFpEF is the most common type of HF in the elderly. HFpEF patients are more likely to have more comorbidities and to be more frail compared to HFrEF patients.

Conclusion
There was a positive correlation between multi-morbidity and frailty in older inpatients admitted with heart failure. There was statistically significant inverse correlation between CCI and ejection fraction but there was no correlation between frailty and ejection.
1299 CO-CREATING A VIDEO FOR TRAINING HEALTHCARE PROFESSIONALS IN DEMENTIA
Authors: Madkor O , Gamal A , Gamal M , Refaat A , ElSayed R , Ali K 
Published: January 2023

Abstract

Introduction
There are 400 thousand people living with dementia (PLWD) in Egypt. Most of the care for PLWD is delivered by family members. Healthcare Professionals (HCP) supporting these families need adequate training. Involving HCP in designing and producing training material ensures sustainability of these educational resources as their content will be socially and culturally relevant.

Methods
The first part of the project involved the lead author (OM) meeting with two geriatricians to identify common challenging situations in dementia. A short video for training HCP in dementia using these situations was produced, based on OM lived experience, and then shared with two old-age psychiatrists for comments. Feedback on the video was subsequently obtained via semi-structured interviews with 16 HCP (2 doctors, 1 nurse, 1 dietitian, 1 communication therapist, 2 social workers, and 9 clinical psychologists) either in person (3), over the phone (1), or virtually (12) approached in two institutions for ageing in Cairo and Alexandria in 2021. The video was finally checked by an adult psychiatrist for consistency with non-violent communication approaches. All interviews were analysed using a thematic framework. Comments and feedback were used to co-produce a final version of the video.

Results
From the initial co-design phase, six frequently-encountered situations were identified: anger, low mood, wandering, repetitive behaviour, refusing support with activities of daily living, and sleep disturbance. Five key qualities for appropriate response in these situations were agreed on: kindness, sensitivity, compassion, avoiding confrontation, and shared-decision making in activities of daily living. The subsequent co-production phase with 19 HCP resulted in an 18-minute: 43-seconds simulation video of six challenging interactions between PLWD and their carers. The video is now freely available on YouTube, https://m.youtube.com/watch?v=ylINBXZwH8M&feature=youtu.be

Conclusions
Involving healthcare professionals in dementia in co-creating a video for training their peers led to a freely available online educational resource.
1311 FRAILTY IN RANDOMISED CONTROLLED TRIALS FOR DEMENTIA OR MILD COGNITIVE IMPAIRMENT
Authors: Wightman H , Quinn T , Mair F S , Lewsey J , McAllister D A , Hanlon P 
Published: January 2023

Abstract

Background
Frailty and dementia have a bidirectional relationship. However, frailty is rarely reported in clinical trials for dementia and mild cognitive impairment (MCI) which limits assessment of trial applicability. This study aims to use a frailty index (FI) to measure frailty using individual participant data (IPD) from clinical trials for MCI and dementia and to quality the prevalence of frailty and its association with serious adverse events (SAEs) and trial attrition.

Methods
We analysed IPD from three dementia (n=1) and MCI (n=2) trials. An FI comprising physical deficits was created for each trial using baseline IPD. Poisson and logistic regression were used to examine associations with SAEs and attrition, respectively. Estimates were pooled in random effects meta-analysis. Analyses were repeated using an FI incorporating cognitive as well as physical deficits, and results compared.

Results
The mean physical FI was 0.13 and 0.14 in the MCI trials and 0.25 in the dementia trial. Frailty prevalence (FI&gt;0.24) was 5.1%, 5.4% in MCI trials and 55.6% in dementia. After including cognitive deficits, prevalence was similar in MCI (4.6% and 4.9%) but higher in dementia (80.7%). 99th percentile of FI (0.29 in MCI, 0.44 in dementia) was lower than in most general population studies. Frailty was associated with SAEs (physical FI IRR = 1.63 [1.43, 1.87]; physical/cognitive FI IRR = 1.67 [1.45, 1.93]). Frailty was not associated with trial attrition (physical FI OR = 1.18 [0.92, 1.53]; physical/cognitive FI OR = 1.17 [0.92, 1.49]).

Conclusion
Measuring frailty from IPD in dementia and MCI trials is feasible. Severe frailty may be under-represented. Frailty is associated with clinically significant outcomes. Including only physical deficits may underestimate frailty in dementia. Frailty can and should be measured in trials for dementia and MCI, and efforts should be made to facilitate inclusion of people living with frailty.
1310 FRAILTY, LONELINESS AND SOCIAL ISOLATION IN THE UK BIOBANK COHORT
Authors: Politis M , Crawford L , Jani B , Nicholl B , Lewsey J , McAllister D A , Mair F S , Hanlon P 
Published: January 2023

Abstract

Background
Three challenges for ageing populations are frailty (a state of reduced physiological reserve), social isolation (objective lack of social connections), and loneliness (subjective experience of feeling alone). These are associated with adverse outcomes. This study aims to examine how frailty in combination with loneliness or social isolation is associated with all-cause mortality and hospitalisation rate using data from UK Biobank, a large population-based research cohort.

Methods
502,456 UK Biobank participants were recruited 2006-2010. Baseline data assessed frailty (via two measures: Fried frailty phenotype, Rockwood frailty index), social isolation, and loneliness. Adjusted cox-proportional hazards models assessed association between frailty in combination with loneliness or social isolation and all-cause mortality. Negative binomial regression models assessed hospitalisation rate.

Findings
Frailty, social isolation, and loneliness are common in UK Biobank (frail as per frailty phenotype 3.38%, frail as per frailty index 4.68%, social isolation 9.04%, loneliness 4.75%). Social isolation/loneliness were more common in frailty/pre-frailty. Frailty is associated with increased mortality regardless of social isolation/loneliness. Hazard ratios for frailty (frailty phenotype) were 3.38 (3.11-3.67) with social isolation and 2.89 (2.75-3.05) without social isolation, 2.94 (2.64-3.27) with loneliness and 2.9 (2.76-3.04) without loneliness. Social isolation was associated with increased mortality at all levels of frailty; loneliness only in robust/pre-frail. Frailty was also associated with hospitalisation regardless of social isolation/loneliness. Incidence rate ratios for frailty (frailty phenotype) were 3.93 (3.66-4.23) with social isolation and 3.75 (3.6-3.9) without social isolation, 4.42 (4.04-4.83) with loneliness and 3.69 (3.55-3.83) without loneliness. At all levels frailty, social isolation/loneliness are associated with increased hospitalisation Results were similar using the frailty index definition.

Conclusion
Social isolation is relevant at all levels frailty. Risk of loneliness is more pronounced in those who are robust or pre-frail. Proactive identification of loneliness, regardless of physical health status may provide opportunities for intervention.
1174 THE ROLE OF HIP FRACTURE IN TRAJECTORIES OF DEPRESSIVE SYMPTOMS AMONG OLDER ADULTS: ANALYSIS FROM THE ENGLISH LONGITUDINAL STUDY
Authors: Milton-Cole R , Ayis S , O'Connell M D L , Smith T , Sheehan K 
Published: January 2023

Abstract

Introduction
Older adults experience ‘Late life depression’. Hip fractures may negatively influence trajectories of depressive symptoms in older adults. This study aimed to determine trajectories of depressive symptoms among older adults in England, overall and for those after hip fracture, and identify characteristics defining trajectory membership.

Methods
Analysis of adults aged 60 years or more (n=7,050), including a hip fracture subgroup (n = 384), from the English Longitudinal Study of Ageing. Latent class growth mixture modelling was completed. Depressive symptom prevalence was estimated at baseline. Chi-squared tests were completed to compare baseline characteristics across trajectories.

Results
Three trajectory groups were identified overall and for those with hip fracture: no-, mild-, and moderate-severe- symptoms. The moderate-severe group comprised 13.7% and 7% of participants for overall and hip fracture populations respectively. Overall, the proportion of participants with depressive symptoms were 0.4%, 12.4% and 65.4% for no-, mild-, and moderate-severe- symptom groups, respectively. For the hip fracture subgroup, these proportions were 0.7%, 28.8%, and 85.2%. Depressive symptoms were stable over time, with a weak trend towards increasing severity for the moderate-severe group. Individuals with moderate-severe trajectories were older, more likely to be female, live alone and had worse health outcomes (p &lt; 0.001).

Conclusions
Older adults, and those after hip fracture, follow one of three trajectories of depressive symptoms which are broadly stable over time. The prevalence of depressive symptoms was lower for those with hip fracture however, when present, the symptoms were more severe than the overall population. Results suggest a role of factors including age, gender, and marital status in depressive symptoms trajectories.