Highly Flexible, High-Performance, and Stretchable Piezoelectric Sensor Based on a Hierarchical Droplet-Shaped Ceramics with Enhanced Damage Tolerance

Stretchable self-powered sensors are of significant interest in next-generation wearable electronics. However, current strategies for creating stretchable piezoelectric sensors based on piezoelectric polymers or 0-3 piezoelectric composites face several challenges such as low piezoelectric activity, low sensitivity, and poor durability. In this paper, a biomimetic soft-rigid hybrid strategy is used to construct a new form of highly flexible, high-performance, and stretchable piezoelectric sensor. Inspired by the hinged bivalve Cristaria plicata, hierarchical droplet-shaped ceramics are manufactured and used as rigid components, where computational models indicate that the unique arched curved surface and rounded corners of this bionic structure can alleviate stress concentrations. To ensure electrical connectivity of the piezoelectric phase during stretching, a patterned liquid metal acts as a soft circuit and a silicone polymer with optimized wettability and stretchability serves as a soft component that forms a strong mechanical interlock with the hierarchical ceramics. The novel sensor design exhibits excellent sensitivity and durability, where the open circuit voltage remains stable after 5000 stretching cycles at 60% strain and 5000 twisting cycles at 180°. To demonstrate its potential in heathcare applications, this new stretchable sensor is successfully used for wireless gesture recognition and assessing the progression of knee osteoarthritis.

Comparative Analysis of Multiple Consensus Genomes of the Same Strain of Marek's Disease Virus Reveals Intrastrain Variation

Current strategies to understand the molecular basis of Marek's disease virus (MDV) virulence primarily consist of cataloguing divergent nucleotides between strains with different phenotypes. However, each MDV strain is typically represented by a single consensus genome despite the confirmed existence of mixed viral populations. To assess the reliability of single-consensus interstrain genomic comparisons, we obtained two additional consensus genomes of vaccine strain CVI988 (Rispens) and two additional consensus genomes of the very virulent strain Md5 by sequencing viral stocks and cultured field isolates. In conjunction with the published genomes of CVI988 and Md5, this allowed us to perform 3-way comparisons between consensus genomes of the same strain. We found that consensus genomes of CVI988 can vary in as many as 236 positions involving 13 open reading frames (ORFs). In contrast, we found that Md5 genomes varied only in 11 positions involving a single ORF. Phylogenomic analyses showed all three Md5 consensus genomes clustered closely together, while also showing that CVI988 GenBank.BAC diverged from CVI988 Pirbright.lab and CVI988 USDA.PA.field . Comparison of CVI988 consensus genomes revealed 19 SNPs in the unique regions of CVI988 GenBank.BAC that were not present in either CVI988 Pirbright.lab or CVI988 USDA.PA.field . Finally, we evaluated the genomic heterogeneity of CVI988 and Md5 populations by identifying positions with >2% read support for alternative alleles in two ultra-deeply sequenced samples. We were able to confirm that both populations of CVI988 and Md5 were mixed, exhibiting a total of 29 and 27 high-confidence minor variant positions, respectively. We did not find any evidence of minor variants in the positions corresponding to the 19 SNPs in the unique regions of CVI988 GenBank.BAC . Taken together, our findings confirm that consensus genomes of the same strain of MDV can vary and suggest that multiple consensus genomes per strain are needed in order to maximize the accuracy of interstrain genomic comparisons.

Soft Self-Healing Robot Driven by New Micro Two-Way Shape Memory Alloy Spring

Soft robotic bodies are susceptible to mechanical fatigue, punctures, electrical breakdown, and aging, which can result in the degradation of performance or unexpected failure. To overcome these challenges, a soft self-healing robot is created using a thermoplastic methyl thioglycolate-modified styrene-butadiene-styrene (MG-SBS) elastomer tube fabricated by melt-extrusion, to allow the robot to self-heal autonomously at room temperature. After repeated damage and being separated into several parts, the robot is able to heal its stiffness and elongation to break to enable almost complete recovery of robot performance after being allowed to heal at room temperature for 24 h. The self-healing capability of the robot is examined across the material scale to robot scale by detailed investigations of the healing process, healing efficiency, mechanical characterization of the robot, and assessment of dynamic performance before and after healing. The self-healing robot is driven by a new micro two-way shape-memory alloy (TWSMA) spring actuator which achieved a crawling speed of 21.6 cm/min, equivalent to 1.57 body length per minute. An analytical model of the robot is created to understand the robot dynamics and to act as an efficient tool for self-healing robot design and optimization. This work therefore provides a new methodology to create efficient, robust, and damage-tolerant soft robots.

Blood-Brain Barrier Dysfunction and Exposure to Head Impacts in University Football Players

OBJECTIVE

To investigate the link between dysfunction of the blood-brain barrier (BBB) and exposure to head impacts in concussed football athletes.

DESIGN

This was a prospective, observational pilot study.

SETTING

Canadian university football.

PARTICIPANTS

The study population consisted of 60 university football players, aged 18 to 25. Athletes who sustained a clinically diagnosed concussion over the course of a single football season were invited to undergo an assessment of BBB leakage.

INDEPENDENT VARIABLES

Head impacts detected using impact-sensing helmets were the measured variables.

MAIN OUTCOME MEASURES

Clinical diagnosis of concussion and BBB leakage assessed using dynamic contrast-enhanced MRI (DCE-MRI) within 1 week of concussion were the outcome measures.

RESULTS

Eight athletes were diagnosed with a concussion throughout the season. These athletes sustained a significantly higher number of head impacts than nonconcussed athletes. Athletes playing in the defensive back position were significantly more likely to sustain a concussion than remain concussion free. Five of the concussed athletes underwent an assessment of BBB leakage. Logistic regression analysis indicated that region-specific BBB leakage in these 5 athletes was best predicted by impacts sustained in all games and practices leading up to the concussion-as opposed to the last preconcussion impact or the impacts sustained during the game when concussion occurred.

CONCLUSIONS

These preliminary findings raise the potential for the hypothesis that repeated exposure to head impacts may contribute to the development of BBB pathology. Further research is needed to validate this hypothesis and to test whether BBB pathology plays a role in the sequela of repeated head trauma.

Enhancing the Performance of Piezoelectric Wind Energy Harvester Using Curve-Shaped Attachments on the Bluff Body

This paper presents a piezoelectric wind energy harvester that operates by a galloping mechanism with different shaped attachments attached to a bluff body. A comparison is made between harvesters that consist of different shaped attachments on a bluff body; these include triangular, circular, square, Y-shaped, and curve-shaped attachments. Simulation of the pressure field and the velocity field variation around the different shaped bluff bodies is performed and it is found that a high pressure difference creates a high lift force on the bluff body with curve-shaped attachments. A theoretical model based on a galloping mechanism is presented, which is verified by experiments. It is observed that the proposed harvester with curve-shaped attachments provides the best performance, where the harvester with a curve-shaped attachments provides the highest voltage and power output compared to the other shaped harvesters examined in this study. This paper provides a new concept for improving the power performance of the piezoelectric wind energy harvesters with modifications made on the bluff body.

Resting state functional connectivity in SLE patients and association with cognitive impairment and blood-brain barrier permeability

OBJECTIVE

Extensive blood-brain barrier (BBB) leakage has been linked to cognitive impairment in SLE. This study aimed to examine the associations of brain functional connectivity (FC) with cognitive impairment and BBB dysfunction among patients with SLE.

METHODS

Cognitive function was assessed by neuropsychological testing (n = 77). Resting-state FC (rsFC) between brain regions, measured by functional MRI (n = 78), assessed coordinated neural activation in 131 regions across five canonical brain networks. BBB permeability was measured by dynamic contrast-enhanced MRI (n = 61). Differences in rsFC were compared between SLE patients with cognitive impairment (SLE-CI) and those with normal cognition (SLE-NC), between SLE patients with and without extensive BBB leakage, and with healthy controls.

RESULTS

A whole-brain rsFC comparison found significant differences in intra-network and inter-network FC in SLE-CI vs SLE-NC patients. The affected connections showed a reduced negative rsFC in SLE-CI compared with SLE-NC and healthy controls. Similarly, a reduced number of brain-wide connections was found in SLE-CI patients compared with SLE-NC (P = 0.030) and healthy controls (P = 0.006). Specific brain regions had a lower total number of brain-wide connections in association with extensive BBB leakage (P = 0.011). Causal mediation analysis revealed that 64% of the association between BBB leakage and cognitive impairment in SLE patients was mediated by alterations in FC.

CONCLUSION

SLE patients with cognitive impairment had abnormalities in brain rsFC which accounted for most of the association between extensive BBB leakage and cognitive impairment.

Wearable sensors and features for diagnosis of neurodegenerative diseases: A systematic review

Objective

Neurodegenerative diseases affect millions of families around the world, while various wearable sensors and corresponding data analysis can be of great support for clinical diagnosis and health assessment. This systematic review aims to provide a comprehensive overview of the existing research that uses wearable sensors and features for the diagnosis of neurodegenerative diseases.

Methods

A systematic review was conducted of studies published between 2015 and 2022 in major scientific databases such as Web of Science, Google Scholar, PubMed, and Scopes. The obtained studies were analyzed and organized into the process of diagnosis: wearable sensors, feature extraction, and feature selection.

Results

The search led to 171 eligible studies included in this overview. Wearable sensors such as force sensors, inertial sensors, electromyography, electroencephalography, acoustic sensors, optical fiber sensors, and global positioning systems were employed to monitor and diagnose neurodegenerative diseases. Various features including physical features, statistical features, nonlinear features, and features from the network can be extracted from these wearable sensors, and the alteration of features toward neurodegenerative diseases was illustrated. Moreover, different kinds of feature selection methods such as filter, wrapper, and embedded methods help to find the distinctive indicator of the diseases and benefit to a better diagnosis performance.

Conclusions

This systematic review enables a comprehensive understanding of wearable sensors and features for the diagnosis of neurodegenerative diseases.

Flexible PVDF-TrFE Nanocomposites with Ag-decorated BCZT Heterostructures for Piezoelectric Nanogenerator Applications

Flexible piezoelectric nanogenerators are playing an important role in delivering power to next-generation wearable electronic devices due to their high-power density and potential to create self-powered sensors for the Internet of Things. Among the range of available piezoelectric materials, poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)-based piezoelectric composites exhibit significant potential for flexible piezoelectric nanogenerator applications. However, the high electric fields that are required for poling cannot be readily applied to polymer composites containing piezoelectric fillers due to the high permittivity contrast between the filler and matrix, which reduces the dielectric strength. In this paper, novel Ag-decorated BCZT heterostructures were synthesized via a photoreduction method, which were introduced at a low level (3 wt %) into the matrix of PVDF-TrFE to fabricate piezoelectric composite films. The effect of Ag nanoparticle loading content on the dielectric, ferroelectric, and piezoelectric properties was investigated in detail, where a maximum piezoelectric energy-harvesting figure of merit of 5.68 × 10^-12 m²/N was obtained in a 0.04Ag-BCZT NWs/PVDF-TrFE composite film, where 0.04 represents the concentration of the AgNO₃ solution. Modeling showed that an optimum performance was achieved by tailoring the fraction and distribution of the conductive silver nanoparticles to achieve a careful balance between generating electric field concentrations to increase the level of polarization, while not degrading the dielectric strength. This work therefore provides a strategy for the design and manufacture of highly polarized piezoelectric composite films for piezoelectric nanogenerator applications.

Combining bio-telemetry and underwater imagery to elucidate the reproductive behaviour of a large, long-lived Australian freshwater teleost

Murray cod Maccullochella peelii (Mitchell) have a key ecological role in ensuring the health of Australia's largest inland waterway, but many aspects surrounding its reproductive strategies in the wild are unknown. From 2015 to 2019 within the Northern Murray-Darling Basin, Australia, we used a combination of bio-telemetry and underwater imagery to quantify the behaviour of Murray cod across their breeding cycle in a natural riverine environment. In most years, breeding behaviour including nest site selection was observed from early-August and spawning from late-August through to late-October, which is considerably earlier than previously reported. There was a positive correlation between the onset of breeding behaviour and week-of-year, and spawning was correlated with moon-phase. Whilst some nesting sites were amongst woody debris and in hollow logs, the majority were located in shallow water on hard substrate underneath undercuts along the riverbank edge. Nests were frequently established in isolated and disconnected pools with little or no measurable flow, suggesting that river hydraulics is not a key component driving spawning of Murray cod across at least some areas of its range. Larvae were observed actively swimming and controlling their position within and near nests and used a scatter tactic when dispersing. We also established that disturbing nesting Murray cod had a negative impact on egg and larval survival. We suggest a review of current regulations to safeguard the long-term conservation of the species across all sections of its range.

Role of autoantibodies and blood-brain barrier leakage in cognitive impairment in systemic lupus erythematosus

Objective

Cognitive impairment is common in patients with SLE but the cause is unknown. The current cross-sectional study examined the association between select SLE-related autoantibodies, other serological biomarkers and extensive blood–brain barrier (BBB) leakage in patients with SLE with and without cognitive impairment. In addition, we determined whether the relationship between SLE autoantibodies, other biomarkers and cognitive impairment differed depending on the presence or absence of concurrent extensive BBB leakage.

Methods

Consecutive patients with SLE, recruited from a single academic medical centre, underwent formal neuropsychological testing for assessment of cognitive function. On the same day, BBB permeability was determined using dynamic contrast-enhanced MRI scanning. SLE autoantibodies and other serological biomarkers were measured. Regression modelling was used to determine the association between cognitive impairment, extensive BBB leakage and autoantibodies/biomarkers.

Results

There were 102 patients with SLE; 90% were female and 88% were Caucasian, with a mean±SD age of 48.9±13.8 years. The mean±SD SLE disease duration was 14.8±11.0 years. Impairment in one or more cognitive tests was present in 47 of 101 (47%) patients and included deficits in information processing speed (9%), attention span (21%), new learning (8%), delayed recall (15%) and executive abilities (21%). Extensive BBB leakage was present in 20 of 79 (25%) patients and was associated with cognitive impairment (15 of 20 (75%) vs 24 of 59 (41%); p=0.01) and shorter disease duration (median (IQR): 7 (8–24 years) vs 15 (2–16 years); p=0.02). No serological parameters were associated with extensive BBB leakage and there was no statistically significant association between cognitive impairment and circulating autoantibodies even after adjusting for BBB leakage.

Conclusions

Extensive BBB leakage alone was associated with cognitive impairment. These findings suggest that BBB leakage is an important contributor to cognitive impairment, regardless of circulating SLE-related autoantibodies.

A retrospective audit of the timescales involved in the diagnosis and management of suspected Achilles tendon ruptures at a single National Health Service trust: A quality service improvement and redesign project

Introduction

The Achilles tendon is the most frequently ruptured tendon. Prompt diagnosis of this injury ensures optimal management decisions are instituted early ensuring the best outcome and patient experience, at minimal cost to the United Kingdom National Health Service. Despite this, regional and national variations to diagnosis and management exist, with anecdotal evidence of inefficiencies in the local patient pathway. To explore this further, a retrospective departmental audit of timescales from presentation to ultrasound diagnosis and definitive treatment decision was undertaken.

Methods

All suspected Achilles tendon ruptures in 2018 were identified through electronic and written patient records, and information on timescales involved in the diagnosis and management of each compiled. Descriptive statistics were used to map each step of the pathway and timescales involved, with performance assessed against local departmental standards and the Swansea Morriston Achilles Rupture Treatment (SMART) protocol.

Results

In total, 119 patients were identified, of which 113 received an ultrasound examination. Local departmental standards were met in the majority of cases, with 78% (n = 88) diagnosed by ultrasound within one week of the request and 83% (n = 91) given a treatment decision within two weeks of presentation. However, this was suboptimal when compared with timeframes utilised for developing the SMART protocol, with only 7% (n = 8) scanned within 48 hours of presentation.

Conclusions

Key areas of the patient pathway were identified for quality service improvement and redesign, with multidisciplinary discussion resulting in the development of a revised patient pathway which expedites diagnosis and treatment for these injuries.

Symptoms reported by Canadians posted in Havana are linked with reduced white matter fibre density

Diplomats representing the USA have reported with unusual neurologic symptoms and MRI changes after being posted in Havana, Cuba between late 2016 and 2018. Here, we examined white matter microstructure and network connectivity of individuals stationed in Havana, using diffusion-weighted MRI, fixel-based analysis and structural connectomics as implemented in MRtrix3. MRI data acquisition and clinical assessments were done in a total of 24 diplomats and their family members and 40 healthy controls. The diplomat data were grouped into an exposed cohort (n = 16) and an unexposed cohort (n = 10), and among these, two individuals were assessed before and after potential exposure. Fixel-based analysis revealed a reduction in fibre density in two specific regions: the fornix and the splenium, in exposed individuals, relative to unexposed individuals and healthy controls. Post hoc analyses showed the effect remained present (P < 0.05) in both regions when comparing exposed and unexposed diplomats; and reduced fibre density was correlated with longer time period stationed in Cuba after age correction. Reduction of fibre density was also found to be linked with clinical symptoms of persistent migraine, tinnitus, sound sensitivity and fatigue. Network statistical comparisons revealed decreased structural connectivity in two distinct networks, comprising subcortical and cortical systems in exposed individuals, relative to unexposed and normative data. While the cause for the differences between the groups remains unknown, our results reveal region-specific white matter injury, that is, significantly correlated with clinical symptoms.

Concussion susceptibility is mediated by spreading depolarization-induced neurovascular dysfunction

The mechanisms underlying the complications of mild traumatic brain injury, including post-concussion syndrome, post-impact catastrophic death, and delayed neurodegeneration remain poorly understood. This limited pathophysiological understanding has hindered the development of diagnostic and prognostic biomarkers and has prevented the advancement of treatments for the sequelae of mild traumatic brain injury.

We aimed to characterize the early electrophysiological and neurovascular alterations following repetitive mild traumatic brain injury and sought to identify new targets for the diagnosis and treatment of individuals at risk of severe post-impact complications. We combined behavioural, electrophysiological, molecular, and neuroimaging techniques in a rodent model of repetitive mild traumatic brain injury. In humans, we used dynamic contrast-enhanced MRI to quantify blood–brain barrier dysfunction after exposure to sport-related concussive mild traumatic brain injury.

Rats could clearly be classified based on their susceptibility to neurological complications, including life-threatening outcomes, following repetitive injury. Susceptible animals showed greater neurological complications and had higher levels of blood–brain barrier dysfunction, transforming growth factor β (TGFβ) signalling, and neuroinflammation compared to resilient animals. Cortical spreading depolarizations were the most common electrophysiological events immediately following mild traumatic brain injury and were associated with longer recovery from impact. Triggering cortical spreading depolarizations in mild traumatic brain injured rats (but not in controls) induced blood–brain barrier dysfunction. Treatment with a selective TGFβ receptor inhibitor prevented blood–brain barrier opening and reduced injury complications. Consistent with the rodent model, blood–brain barrier dysfunction was found in a subset of human athletes following concussive mild traumatic brain injury.

We provide evidence that cortical spreading depolarization, blood–brain barrier dysfunction, and pro-inflammatory TGFβ signalling are associated with severe, potentially life-threatening outcomes following repetitive mild traumatic brain injury. Diagnostic-coupled targeting of TGFβ signalling may be a novel strategy in treating mild traumatic brain injury.

Evaluation of Golden-Angle-Sampled Dynamic Contrast-Enhanced MRI Reconstruction Using Objective Image Quality Measures: A Simulated Phantom Study

We aim to extend the use of image quality metrics (IQMs) from static magnetic resonance imaging (MRI) applications to dynamic MRI studies. We assessed the use of 2 IQMs, the root mean square error and structural similarity index, in evaluating the reconstruction of quantitative dynamic contrast-enhanced (DCE) MRI data acquired using golden-angle sampling and compressed sensing (CS). To address the difficulty of obtaining ground-truth knowledge of parameters describing dynamics in real patient data, we developed a Matlab simulation framework to assess quantitative CS-DCE-MRI. We began by validating the response of each IQM to the CS-MRI reconstruction process using static data and the performance of our simulation framework with simple dynamic data. We then extended the simulations to the more realistic extended Tofts model. When assessing the Tofts model, we tested 4 different methods of selecting a reference image for the IQMs. Results from the retrospective static CS-MRI reconstructions showed that each IQM is responsive to the CS-MRI reconstruction process. Simulations of a simple contrast evolution model validated the performance of our framework. Despite the complexity of the Tofts model, both IQM scores correlated well with the recovery accuracy of a central model parameter for all reference cases studied. This finding may form the basis of algorithms for automated selection of image reconstruction aspects, such as temporal resolution, in golden-angle-sampled CS-DCE-MRI. These further suggest that objective measures of image quality may find use in general dynamic MRI applications.

Construction of Bio-Piezoelectric Platforms: From Structures and Synthesis to Applications

Piezoelectric materials, with their unique ability for mechanical-electrical energy conversion, have been widely applied in important fields such as sensing, energy harvesting, wastewater treatment, and catalysis. In recent years, advances in material synthesis and engineering have provided new opportunities for the development of bio-piezoelectric materials with excellent biocompatibility and piezoelectric performance. Bio-piezoelectric materials have attracted interdisciplinary research interest due to recent insights on the impact of piezoelectricity on biological systems and their versatile biomedical applications. This review therefore introduces the development of bio-piezoelectric platforms from a broad perspective and highlights their design and engineering strategies. State-of-the-art biomedical applications in both biosensing and disease treatment will be systematically outlined. The relationships between the properties, structure, and biomedical performance of the bio-piezoelectric materials are examined to provide a deep understanding of the working mechanisms in a physiological environment. Finally, the development trends and challenges are discussed, with the aim to provide new insights for the design and construction of future bio-piezoelectric materials.

Dynamic Polymer Networks: A New Avenue towards Sustainable and Advanced Soft Machines

While the fascinating field of soft machines has grown rapidly over the last two decades, the materials they are constructed from have remained largely unchanged during this time. Parallel activities have led to significant advances in the field of dynamic polymer networks, leading to the design of three-dimensionally cross-linked polymeric materials that are able to adapt and transform through stimuli-induced bond exchange. Recent work has begun to merge these two fields of research by incorporating the stimuli-responsive properties of dynamic polymer networks into soft machine components. These include dielectric elastomers, stretchable electrodes, nanogenerators, and energy storage devices. In this Minireview, we outline recent progress made in this emerging research area and discuss future directions for the field.

AB0803 EXPERIENCES OF SCREENING AND DIAGNOSIS FROM THE PERSPECTIVE OF PATIENTS WITH PSORIASIS AND PSORIATIC ARTHRITIS (PSA)

Background:

Psoriatic arthritis (PsA) is an inflammatory arthritis characterised by pain, swelling and stiffness in the joints and affects approximately 0.3 to 1.02% of the UK population [1]. PsA may result in limited physical function and reduced quality of life [2] and is associated with work disability and unemployment [3]. Patients who have the inflammatory skin condition, psoriasis, are at greater risk of developing PsA than those without.

Objectives:

There is no definitive test for PsA. It is usually diagnosed by rheumatologists in secondary care, after referral from primary care. Evidence suggests a delay in diagnosis results in worse outcomes for patients. This study is nested within a randomised controlled trial (RCT) of a new clinical care pathway. The RCT is testing whether screening primary care patients with psoriasis for symptoms of PsA leads to earlier diagnosis and improved outcomes, compared to usual care. This qualitative study explored the acceptability and impact of screening.

Methods:

Telephone interviews were conducted with patients with psoriasis from two secondary UK care centres taking part in the RCT. The semi-structured interviews explored patients’ thoughts and feelings around screening, the impact of the screening outcome and any changes they made as a result. The semi-structured format allowed flexibility to ask questions that probed more deeply and develop new lines of enquiry based on patients’ responses. Patients who did and did not receive a diagnosis of PsA were interviewed.

Results:

Twenty-four patients participated in the study (15 women / 9 men) ranging in age from 35 to 73 years old. The length of time patients had psoriasis ranged from 6 to 60 years. Eleven patients were diagnosed with PsA. A Framework Analysis Approach was used to analyse the data. This allowed for an exploration of the predefined areas (the screening process) as well as remaining open to capturing other related experiences and views of patients. Four main themes represent the data (Table 1).

Table 1.Main themeSub-themes1. Living with psoriasis and psoriatic arthritis:1. Understanding of psoriasis – causes, symptoms, treatments‘It’s [psoriasis] socially debilitating…makes you look a real mess’2. Effects of psoriasis on self, personal and working life‘It’s almost as if the world’s on your shoulders’3. Awareness of PsA2. Experience of screening:1. Thoughts and feelings prior to screening‘I was able to talk and be listened to’2. Valuing ‘high quality’ care‘It’s a lightbulb moment…explained why things were a bit stiff and achy’3. Impact of screening outcome3. Gaining control:1. Increased awareness and knowledge of psoriasis and PsA‘element of surprise that this arthritis should be connected to it [psoriasis]’2. Improved self-management‘You’ve got to learn to listen to your body’3. Early diagnosis of PsA4. Future screening programs:1. Changes to questionnaires‘there weren’t really any questions about were you in pain’2. Use of case studies, sign-posting‘support groups…peer support is crucial with long-term conditions’3. Removing barriers to screening

Conclusion:

This study indicates screening was viewed as a positive and reassuring experience. Patients valued the fact that screening appointments were not rushed and felt they were being listened to. Patients valued learning about psoriasis and PsA and referred to making changes beneficial to their health. Screening enabled patients to get the help they needed if diagnosed, provided relief if not diagnosed, and sometimes led to the diagnosis of a different condition.

References:

[1]Gladman DD, Antoni C, Mease P, Clegg DO, Nash P. Psoriatic arthritis: epidemiology, clinical features, course, and outcome. Ann Rheum Dis 2005;64(Suppl 2):ii14–7

[2]Tillett W, de-Vries C, McHugh NJ. Work disability in psoriatic arthritis: a systematic review. Rheumatology 2012;51:275–83.

[3]Alinaghi F, Calov M, Kristensen LE et al. Prevalence of psoriatic arthritis in patients with psoriasis: a systematic review and meta-analysis of observational and clinical studies. J Am Acad Dermatol 2019;80:251–65.e19

Acknowledgements:

On behalf of the PROMPT study team.

Disclosure of Interests:

None declared

Dual response of osteoblast activity and antibacterial properties of polarized strontium substituted hydroxyapatite-Barium strontium titanate composites with controlled strontium substitution

To mimic the electrical properties of natural bone, controlled strontium substitution of both hydroxyapatite and ferroelectric barium titanate were achieved by mixing in the ratio 30:70 by weight. The composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy to investigate the phase composition and microstructure of the composites. Unpolarized and polarized strontium hydroxyapatite (SrHA)-barium strontium titanate (BST) composites with controlled degree of Sr substitution were examined, including 5SrHA-5BST (5% Sr substitution in both components) and 10SrHA-10BST composites. The 10SrHA-10BST composite showed a higher osteoblast activity, as observed from the cell viability studies performed using CCK-8 assay. The polarized composites showed promise against Staphylococcus aureus bacteria by minimizing the adhesion and growth of bacteria, as compared with their unpolarized counterparts. The polarized 10SrHA-10BST was found to be superior than all other composites. As a result, the approach of polarization of SrHA-BST composites has been found to be an effective bone substitute material in controlled enhancement of osteoblast growth with simultaneous reduction of bacterial infection.

Simultaneous quantification of SPIO and gadolinium contrast agents using MR fingerprinting

PURPOSE

Develop a magnetic resonance fingerprinting (MRF) methodology with R₂^∗ quantification, intended for use with simultaneous contrast agent concentration mapping, particularly gadolinium (Gd) and iron labelled CD8+ T cells.

METHODS

Variable-density spiral SSFP MRF was used, modified to allow variable TE, and with an exp.(-TE·R₂^∗) dictionary modulation. In vitro phantoms containing SPIO labelled cells and/or gadolinium were used to validate parameter maps, probe undersampling capacity, and verify dual quantification capabilities. A C57BL/6 mouse was imaged using MRF to demonstrate acceptable in vivo resolution and signal at 8× undersampling necessary for a 25-min scan.

RESULTS

Strong agreement was found between conventional and MRF-derived values for R₁, R₂, and R₂^∗. Expanded MRF allowed quantification of iron-loaded CD8+ T cells. Results were robust to 8× undersampling and enabled recreation of relaxation profiles for both a Gd agent and iron labelled cells simultaneously. In vivo data demonstrated sufficient SNR in undersampled data for parameter mapping to visualise key features.

CONCLUSION

MRF can be expanded to include R₁, R₂, and R₂^∗ mapping required for simultaneous quantification of gadolinium and SPIO in vitro, allowing for potential implementation of a variety of future in vivo studies using dual MR contrast agents, including molecular imaging of labelled cells.

Polarisation tuneable piezo-catalytic activity of Nb-doped PZT with low Curie temperature for efficient CO2 reduction and H2 generation

The reduction of CO₂ into useful hydrocarbon chemicals has attracted significant attention in light of the depletion in fossil resources and the global demand for sustainable sources of energy. In this paper, we demonstrate piezo-catalytic electrochemical reduction of CO₂ by exploiting low Curie temperature, T _c ∼ 38 °C, Nb-doped lead zirconate titanate (PZTN) piezoelectric particulates. The large change in spontaneous polarisation of PZTN due to the acoustic pressures from to the application of ultrasound in the vicinity of the T _c creates free charges for CO₂ reduction. The effect of applied acoustic power, particulate agglomeration and the impact of T _c on piezo-catalytic performance are explored. By optimization of the piezo-catalytic effect a promising piezo-catalytic CO₂ reduction rate of 789 μmol g^-1 h^-1 is achieved, which is much larger than the those obtained from pyro-catalytic effects. This efficient and polarisation tunable piezo-catalytic route has potential to promote the development of CO₂ reduction via the utilization of vibrational energy for environmental improvement.

Triboelectric and Piezoelectric Nanogenerators for Future Soft Robots and Machines

The triboelectric nanogenerator (TENG) and piezoelectric nanogenerator (PENG) are two recently developed technologies for effective harvesting of ambient mechanical energy for the creation of self-powered systems. The advantages of TENGs and PENGs which include large open-circuit output voltage, low cost, ease of fabrication, and high conversion efficiency enable their application as new flexible sensors, wearable devices, soft robotics, and machines. This perspective provides an overview of the current state of the art in triboelectric and piezoelectric devices that are used as self-powered sensors and energy harvesters for soft robots and machines; hybrid approaches that combine the advantages of both mechanisms are also discussed. To improve system performance and efficiency, the potential of providing self-powered soft systems with a degree of multifunctionality is investigated. This includes optical sensing, transparency, self-healing, water resistance, photo-luminescence, or an ability to operate in hostile environments such as low temperature, high humidity, or high strain/stretch. Finally, areas for future research directions are identified.

Blood-brain barrier leakage in systemic lupus erythematosus is associated with gray matter loss and cognitive impairment

OBJECTIVES

To examine the association between blood-brain barrier (BBB) integrity, brain volume and cognitive dysfunction in adult patients with systemic lupus erythematosus (SLE).

METHODS

A total of 65 ambulatory patients with SLE and 9 healthy controls underwent dynamic contrast-enhanced MRI scanning, for quantitative assessment of BBB permeability. Volumetric data were extracted using the VolBrain pipeline. Global cognitive function was evaluated using a screening battery consisting of tasks falling into five broad cognitive domains, and was compared between patients with normal versus extensive BBB leakage.

RESULTS

Patients with SLE had significantly higher levels of BBB leakage compared with controls (p=0.04). Extensive BBB leakage (affecting over >9% of brain volume) was identified only in patients with SLE (16/65; 24.6%), who also had smaller right and left cerebral grey matter volumes compared with controls (p=0.04). Extensive BBB leakage was associated with lower global cognitive scores (p=0.02), and with the presence of impairment on one or more cognitive tasks (p=0.01).

CONCLUSION

Our findings provide evidence for a link between extensive BBB leakage and changes in both brain structure and cognitive function in patients with SLE. Future studies should investigate the mechanisms underlying BBB-mediated cognitive impairment, validate the diagnostic utility of BBB imaging, and determine the potential of targeting the BBB as a therapeutic strategy in patients with SLE.

Congenital mesoblastic nephroma: a single-centre series

BACKGROUND

Congenital mesoblastic nephroma is a rare disease. Treatment is surgical in the first instance. Chemotherapy has traditionally been thought not to have a role. Recent literature suggests a 50% mortality rate for recurrent/metastatic disease.

MATERIALS AND METHODS

This study is a retrospective case review of prospectively collected data. Demographics, histopathology, treatment, outcomes and follow up were reviewed.

RESULTS

Nine patients, 6 male and 3 female, were included. The median age at presentation was one month (range 0-7 months); follow-up was for a median of 21.5 months (range 16-79 months). Two patients had mixed and classical subtypes and the other five had the cellular subtype. Surgery was completed by an open procedure in eight patients and laparoscopically in one. There were three recurrences; two were local and one was pulmonary. Recurrences were treated with a combination of chemotherapy, radiotherapy and surgery. One patient with recurrent disease died from acute-on-chronic respiratory failure secondary to lung irradiation but was disease free. The other eight are disease free, alive and well with no sequelae at latest follow-up.

CONCLUSIONS

Surgery remains the mainstay of management with chemo- and radiotherapy reserved for unresectable tumours or adjuvant management of recurrent disease. Specimen-positive margins are not an indication for instituting chemotherapy. The tyrosine kinase pathway seems to be a potential target for future chemotherapeutic agents although it is too early to assess how that will impact on the management of congenital mesoblastic nephroma.

Blood-brain barrier imaging as a potential biomarker for bipolar disorder progression

Bipolar disorder affects approximately 2% of the population and is typically characterized by recurrent episodes of mania and depression. While some patients achieve remission using mood-stabilizing treatments, a significant proportion of patients show progressive changes in symptomatology over time. Bipolar progression is diverse in nature and may include a treatment-resistant increase in the frequency and severity of episodes, worse psychiatric and functional outcomes, and a greater risk of suicide. The mechanisms underlying bipolar disorder progression remain poorly understood and there are currently no biomarkers for identifying patients at risk. The objective of this study was to explore the potential of blood-brain barrier (BBB) imaging as such a biomarker, by acquiring the first imaging data of BBB leakage in bipolar patients, and evaluating the potential association between BBB dysfunction and bipolar symptoms. To this end, a cohort of 36 bipolar patients was recruited through the Mood Disorders Clinic (Nova Scotia Health Authority, Canada). All patients, along with 14 control subjects (matched for sex, age and metabolic status), underwent contrast-enhanced dynamic MRI scanning for quantitative assessment of BBB leakage as well as clinical and psychiatric evaluations. Outlier analysis has identified a group of 10 subjects with significantly higher percentages of brain volume with BBB leakage (labeled the "extensive BBB leakage" group). This group consisted exclusively of bipolar patients, while the "normal BBB leakage" group included the entire control cohort and the remaining 26 bipolar subjects. Among the bipolar cohort, patients with extensive BBB leakage were found to have more severe depression and anxiety, and a more chronic course of illness. Furthermore, all bipolar patients within this group were also found to have co-morbid insulin resistance, suggesting that insulin resistance may increase the risk of BBB dysfunction in bipolar patients. Our findings demonstrate a clear link between BBB leakage and greater psychiatric morbidity in bipolar patients and highlight the potential of BBB imaging as a mechanism-based biomarker for bipolar disorder progression.

The progression rate of peripheral arterial disease in patients with intermittent claudication: a systematic review

Background

Intermittent claudication (IC) is the most common symptom of peripheral arterial disease and is generally treated conservatively due to limited prognostic evidence to support early revascularisation in the individual patient. This approach may lead to the possible loss of opportunity of early revascularisation in patients who are more likely to deteriorate to critical limb ischaemia. The aim of this review is to evaluate the available literature related to the progression rate of symptomatic peripheral arterial disease.

Methods

We conducted a systematic review of the literature in PubMed and MEDLINE, Cochrane library, Elsevier, Web of Science, CINAHL and Opengrey using relevant search terms to identify the progression rate of peripheral arterial disease in patients with claudication. Outcomes of interest were progression rate in terms of haemodynamic measurement and time to development of adverse outcomes. Two independent reviewers determined study eligibility and extracted descriptive, methodologic, and outcome data. Quality of evidence was evaluated using the Cochrane recommendations for assessing risk of bias and was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

Seven prospective cohort studies and one retrospective cohort study were identified and included in this review with the number of participants in each study ranging from 38 to 1244. Progression rate reports varied from a yearly decrease of 0.01 in ankle-brachial pressure index (ABPI) to a yearly decrease ABPI of 0.014 in 21% of participants. Quality of evidence ranged from low to moderate mostly due to limited allocation concealment at recruitment and survival selection bias.

Conclusions

Progression of PAD in IC patients is probably underestimated in the literature due to study design issues. Predicting which patients with claudication are likely to deteriorate to critical limb ischaemia is difficult since there is a lack of evidence related to lower limb prognosis. Further research is required to enable early identification of patients at high risk of progressing to critical ischaemia and appropriate early revascularisation to reduce lower limb morbidity.

Model-free prostate cancer segmentation from dynamic contrast-enhanced MRI with recurrent convolutional networks: A feasibility study

Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) is a method of temporal imaging that is commonly used to aid in prostate cancer (PCa) diagnosis and staging. Typically, machine learning models designed for the segmentation and detection of PCa will use an engineered scalar image called K^trans to summarize the information in the DCE time-series images. This work proposes a new model that amalgamates the U-net and the convGRU neural network architectures for the purpose of interpreting DCE time-series in a temporal and spatial basis for segmenting PCa in MR images. Ultimately, experiments show that the proposed model using the DCE time-series images can outperform a baseline U-net segmentation model using K^trans. However, when other types of scalar MR images are considered by the models, no significant advantage is observed for the proposed model.

Asymptotically Optimal Kinematic Design of Robots using Motion Planning

In highly constrained settings, e.g., a tentaclelike medical robot maneuvering through narrow cavities in the body for minimally invasive surgery, it may be difficult or impossible for a robot with a generic kinematic design to reach all desirable targets while avoiding obstacles. We introduce a design optimization method to compute kinematic design parameters that enable a single robot to reach as many desirable goal regions as possible while avoiding obstacles in an environment. Our method appropriately integrates sampling based motion planning in configuration space into stochastic optimization in design space so that, over time, our evaluation of a design's ability to reach goals increases in accuracy and our selected designs approach global optimality. We prove the asymptotic optimality of our method and demonstrate performance in simulation for (i) a serial manipulator and (ii) a concentric tube robot, a tentacle-like medical robot that can bend around anatomical obstacles to safely reach clinically- relevant goal regions.

Recent advances in metal sulfides: from controlled fabrication to electrocatalytic, photocatalytic and photoelectrochemical water splitting and beyond

This review describes an in-depth overview and knowledge on the variety of synthetic strategies for forming metal sulfides and their potential use to achieve effective hydrogen generation and beyond.

Highly Stretchable Capacitive Sensor with Printed Carbon Black Electrodes on Barium Titanate Elastomer Composite

Wearable electronics and soft robotics are emerging fields utilizing soft and stretchable sensors for a variety of wearable applications. In this paper, the fabrication of a highly stretchable capacitive sensor with a printed carbon black/Ecoflex interdigital capacitor is presented. The highly stretchable capacitive sensor was fabricated on a substrate made from barium titanate⁻EcoflexTM 00-30 composite, and could withstand stretching up to 100%. The designed highly stretchable capacitive sensor was robust, and showed good repeatability and consistency when stretched and relaxed for over 1000 cycles.

Flexible and active self-powered pressure, shear sensors based on freeze casting ceramic-polymer composites

Self-powered flexible electronics are of particular interest and important for next generation electronics due to their light weight, flexible and self-sustainable properties. Many self-powered sensors made from piezoelectric composite materials are either inflexible or possess low piezoelectricity. In this work, we demonstrate self-powered flexible and highly active pressure and shear sensors based on freeze casting ceramic-polymer structures. A lamellar lead zirconate titanate (PZT) structure is initially developed via freeze-casting and the piezoelectric composites are formed by impregnating a polydimethylsiloxane (PDMS) matrix into the aligned pore channels. The structured PZT-PDMS composites exhibited a high effective longitudinal piezoelectric coefficient (d ₃₃*) of 750 pC N^-1, which is higher than that of the monolithic ceramic due to the combination of bending and flexural effects. The use of freeze casting enables the manufacture of complex and arbitrary shaped 3D piezoelectric architectures, along with the unique advantages of low-cost and ease of fabrication. A 14 × 14 mm² PZT-PDMS pressure sensor was able to bend to a small radius of 8 mm and maintain a high d ₃₃. Furthermore, the manufactured self-powered sensors are demonstrated in a range of applications, such as acceleration, strain and touch sensors that use the d ₃₃, d ₃₁ and d ₁₅ coefficients to detect longitudinal, transverse and shear loads. This work expands on the potential applications of freeze casting and provides new opportunities for the manufacture of future electronic sensors.

Closed-Loop Global Motion Planning for Reactive, Collision-Free Execution of Learned Tasks

We present a robot motion planning approach for performing a learned task while reacting to the movement of obstacles and task-relevant objects. We employ a closed-loop, sampling-based motion planner operating multiple times a second that senses obstacles and task-relevant objects and generates collision-free motion plans based on a learned-task model. The task model is learned from expert demonstrations prior to task execution and is represented as a hidden Markov model. During task execution, our motion planner quickly searches in the Cartesian product of the task model and a probabilistic roadmap for a collision-free plan with features most similar to the demonstrations given the current locations of the task-relevant objects. We accelerate replanning using a fast bidirectional search and by biasing the sampling distribution using information from the learned-task model. We show the efficacy of our approach with the Baxter robot performing two tasks.

Graphene Ink Laminate Structures on Poly(vinylidene difluoride) (PVDF) for Pyroelectric Thermal Energy Harvesting and Waste Heat Recovery

Thermal energy can be effectively converted into electricity using pyroelectrics, which act as small scale power generator and energy harvesters providing nanowatts to milliwatts of electrical power. In this paper, a novel pyroelectric harvester based on free-standing poly(vinylidene difluoride) (PVDF) was manufactured that exploits the high thermal radiation absorbance of a screen printed graphene ink electrode structure to facilitate the conversion of the available thermal radiation energy into electrical energy. The use of interconnected graphene nanoplatelets (GNPs) as an electrode enable high thermal radiation absorbance and high electrical conductivity along with the ease of deposition using a screen print technique. For the asymmetric structure, the pyroelectric open-circuit voltage and closed-circuit current were measured, and the harvested electrical energy was stored in an external capacitor. For the graphene ink/PVDF/aluminum system the closed circuit pyroelectric current improves by 7.5 times, the open circuit voltage by 3.4 times, and the harvested energy by 25 times compared to a standard aluminum/PVDF/aluminum system electrode design, with a peak energy density of 1.13 μJ/cm³. For the pyroelectric device employed in this work, a complete manufacturing process and device characterization of these structures are reported along with the thermal conductivity of the graphene ink. The material combination presented here provides a new approach for delivering smart materials and structures, wireless technologies, and Internet of Things (IoT) devices.

Functionalization of BaTiO3 nanoparticles with electron insulating and conducting organophosphazene-based hybrid materials

Structuring of core–shell dielectric nanoparticles.

Magnetic resonance fingerprinting based on realistic vasculature in mice

Magnetic resonance fingerprinting (MRF) was recently proposed as a novel strategy for MR data acquisition and analysis. A variant of MRF called vascular MRF (vMRF) followed, that extracted maps of three parameters of physiological importance: cerebral oxygen saturation (SatO₂), mean vessel radius and cerebral blood volume (CBV). However, this estimation was based on idealized 2-dimensional simulations of vascular networks using random cylinders and the empirical Bloch equations convolved with a diffusion kernel. Here we focus on studying the vascular MR fingerprint using real mouse angiograms and physiological values as the substrate for the MR simulations. The MR signal is calculated ab initio with a Monte Carlo approximation, by tracking the accumulated phase from a large number of protons diffusing within the angiogram. We first study the identifiability of parameters in simulations, showing that parameters are fully estimable at realistically high signal-to-noise ratios (SNR) when the same angiogram is used for dictionary generation and parameter estimation, but that large biases in the estimates persist when the angiograms are different. Despite these biases, simulations show that differences in parameters remain estimable. We then applied this methodology to data acquired using the GESFIDE sequence with SPIONs injected into 9 young wild type and 9 old atherosclerotic mice. Both the pre injection signal and the ratio of post-to-pre injection signals were modeled, using 5-dimensional dictionaries. The vMRF methodology extracted significant differences in SatO₂, mean vessel radius and CBV between the two groups, consistent across brain regions and dictionaries. Further validation work is essential before vMRF can gain wider application.

Characterisation and Modelling of Meshed Electrodes on Free Standing Polyvilylidene Difluoride (PVDF) Films for Enhanced Pyroelectric Energy Harvesting

Flexible pyroelectric energy generators provide unique features for harvesting temperature fluctuations which can be effectively enhanced using meshed electrodes that improve thermal conduction, convection and radiation into the pyroelectric. In this paper, thermal radiation energy is continuously harvested with pyroelectric free standing Polyvilylidene Difluoride (PVDF) films over a large number of heat heat cycles using a novel micro-sized symmetrical patterned meshed electrode. It is shown that, for the meshed electrode geometries considered in this work, the polarisation-field (P-E), current-field (I-E) characteristics and device capacitance are unaffected since the fringing fields were generally small; this is verified using numerical simulations and comparison with experimental measurements. The use of meshed electrodes has been shown to significantly improve both the open circuit voltage (16 V to 59 V) and closed-circuit current (9 nA to 32 nA). The pyroelectric alternating current (AC) is rectified for direct current (DC) storage and 30% reduction in capacitor charging time is achieved by using the optimum meshed electrodes. The use of meshed electrodes on ferroelectric materials provides an innovative route to improve their performance in applications such as wearable devices, novel flexible sensors and large scale pyroelectric energy harvesters.hese instructions give you guidelines for preparing papers for IEEE Transactions and Journals. Use this document as a template if you are using Microsoft Word 6.0 or later. Otherwise, use this document as an instruction set. The electronic file of your paper will be formatted further at IEEE. Paper titles should be written in uppercase and lowercase letters, not all uppercase. Avoid writing long formulas with subscripts in the title; short formulas that identify the elements are fine (e.g., "Nd-Fe-B"). Do not write "(Invited)" in the title. Full names of authors are preferred in the author field, but are not required. Put a space between authors' initials. Define all symbols used in the abstract. Do not cite references in the abstract. Do not delete the blank line immediately above the abstract; it sets the footnote at the bottom of this column.

IFPA meeting 2015 workshop report II: mechanistic role of the placenta in fetal programming; biomarkers of placental function and complications of pregnancy

Workshops are an integral component of the annual International Federation of Placenta Association (IFPA) meeting, allowing for networking and focused discussion related to specialized topics on the placenta. At the 2015 IFPA meeting (Brisbane, Australia) twelve themed workshops were held, three of which are summarized in this report. These workshops focused on various aspects of placental function, particularly in cases of placenta-mediated disease. Collectively, these inter-connected workshops highlighted the role of the placenta in fetal programming, the use of various biomarkers to monitor placental function across pregnancy, and the clinical impact of novel diagnostic and surveillance modalities in instances of late onset fetal growth restriction (FGR).

Systemic injection of CK2.3, a novel peptide acting downstream of bone morphogenetic protein receptor BMPRIa, leads to increased trabecular bone mass

Bone Morphogenetic Protein 2 (BMP2) regulates bone integrity by driving both osteogenesis and osteoclastogenesis. However, BMP2 as a therapeutic has significant drawbacks. We have designed a novel peptide CK2.3 that blocks the interaction of Casein Kinase 2 (CK2) with Bone Morphogenetic Protein Receptor type Ia (BMPRIa), thereby activating BMP signaling pathways in the absence of ligand. Here, we show that CK2.3 induced mineralization in primary osteoblast cultures isolated from calvaria and bone marrow stromal cells (BMSCs) of 8 week old mice. Further, systemic tail vein injections of CK2.3 in 8 week old mice resulted in increased bone mineral density (BMD) and mineral apposition rate (MAR). In situ immunohistochemistry of the femur found that CK2.3 injection induced phosphorylation of extracellular signal-related kinase (ERK), but not Smad in osteocytes and osteoblasts, suggesting that CK2.3 signaling occurred through Smad independent pathway. Finally mice injected with CK2.3 exhibited decreased osteoclast differentiation and osteoclast activity. These data indicate that the novel mimetic peptide CK2.3 activated BMPRIa downstream signaling to enhance bone formation without the increase in osteoclast activity that accompanies BMP 2 stimulation.