Recyclable and Biobased Vitrimers for Carbon Fibre-Reinforced Composites-A Review

Economic and environmental concerns over the accumulation of end-of-life carbon fibre composite waste have led to increased attention to sustainable materials with low environmental impact. Over decades of research, vitrimers, a modern class of covalent adaptable networks, have bridged the gap between thermoplastics and thermosets. With the distinguishing feature of dynamic covalent bonds, vitrimers can be rearranged and reprocessed within their existing network structures in response to external stimuli such as heat or light. This poses a unique solution to repairing damaged composites, extending their service life, and reducing post-consumer waste. However, the synthesis of vitrimers often requires petrochemical consumption, which increases their carbon footprint. Using bio-based materials could be a promising solution to reduce the reliance on petrochemicals and their related pollution. This review compiles the contemporary requirements for bio-based vitrimers regarding their properties, scalability, and recycling features. This article also presents a comprehensive overview of the pathways to produce sustainable bio-based vitrimers and an overview of promising studies showing the potential uses of bio-derived vitrimers on carbon fibre composite productions.

Review of Approaches to Minimise the Cost of Simulation-Based Optimisation for Liquid Composite Moulding Processes

The utilisation of numerical process simulation has greatly facilitated the challenging task of liquid composite moulding (LCM) process optimisation, providing ease of solution evaluation at a significantly reduced cost compared to complete reliance on physical prototyping. However, due to the process complexity, such process simulation is still considerably expensive at present. In this paper, cost-saving approaches to minimising the computational cost of simulation-based optimisation for LCM processes are compiled and discussed. Their specific applicability, efficacy, and suitability for various optimisation/moulding scenarios are extensively explored in detail. The comprehensive analysation and assimilation of their operation alongside applicability for the problem domain of interest are accomplished in this paper to further complement and contribute to future simulation-based optimisation capabilities for composite moulding processes. The importance of balancing the cost-accuracy trade-off is also repeatedly emphasised, allowing for substantial cost reductions while ensuring a desirable level of optimization reliability.

Application of KNN and ANN Metamodeling for RTM Filling Process Prediction

Process simulation is frequently adopted to facilitate the optimization of the resin transfer molding process. However, it is computationally costly to simulate the multi-physical, multi-scale process, making it infeasible for applications involving huge datasets. In this study, the application of K-nearest neighbors and artificial neural network metamodels is proposed to build predictive surrogate models capable of relating the mold-filling process input-output correlations to assist mold designing. The input features considered are the resin injection location and resin viscosity. The corresponding output features investigated are the number of vents required and the resultant maximum injection pressure. Upon training, both investigated metamodels demonstrated desirable prediction accuracies, with a low prediction error range of 5.0% to 15.7% for KNN metamodels and 6.7% to 17.5% for ANN metamodels. The good prediction results convincingly indicate that metamodeling is a promising option for composite molding applications, with encouraging prospects for data-intensive applications such as process digital twinning.

Magnetically Cured Macroradical Epoxy as Antimicrobial Coating

The radical-bearing epoxy monomer could be the ideal embodiment of multifunctionality in epoxy-based materials. This study demonstrates the potential of macroradical epoxies as surface coating materials. A diepoxide monomer derivatized with a stable nitroxide radical is polymerized with a diamine hardener under the influence of a magnetic field. The magnetically oriented and stable radicals in the polymer backbone render the coatings antimicrobial. The unconventional use of magnets during polymerization proved crucial in correlating the structure-property relationships with antimicrobial performance inferred from oscillatory rheological technique, polarized macro-attenuated total reflectance - infrared (macro-ATR-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The magnetic thermal curing influenced the surface morphology, resulting in a synergy of the coating's radical nature with microbiostatic performance assessed using the Kirby-Bauer test and liquid chromatography - mass spectroscopy (LC-MS). Further, the magnetic curing of blends with a traditional epoxy monomer demonstrates that radical alignment is more critical than radical density in imparting biocidal behavior. This study shows how the systematic use of magnets during polymerization could pave for probing more significant insights into the mechanism of antimicrobial action in radical-bearing polymers.

Evaluation of the Failure Mechanism in Polyamide Nanofibre Veil Toughened Hybrid Carbon/Glass Fibre Composites

The interface of hybrid carbon/E-glass fibres composite is interlayered with Xantu.layr^® polyamide 6,6 nanofibre veil to localise cracking to promote a gradual failure. The pseudo-ductile response of these novel stacking sequences examined under quasi-static three-point bending show a change to the failure mechanism. The change in failure mechanism due to the interfacial toughening is examined via SEM micrographs. The incorporation of veil toughening led to a change in the dominant failure mechanism, resulting in fibre yielding by localised kinking and reduced instances of buckling failure. In alternated carbon and glass fibre samples with glass fibre undertaking compression, a pseudo-ductile response with veil interlayering was observed. The localisation of the fibre failure, due to the inclusion of the veil, resulted in kink band formations which were found to be predictable in previous micro buckling models. The localisation of failure by the veil interlayer resulted in a pseudo-ductile response increasing the strain before failure by 24% compared with control samples.

High Performance Carbon Fiber Structural Batteries Using Cellulose Nanocrystal Reinforced Polymer Electrolyte

In recent years, structural batteries have received great attention for future automotive application in which a load-bearing car panel is used as an energy storage. However, based on the current advances, achieving both high ionic conductivity and mechanical performance has remained a challenge. To address this challenge, this study introduces a cellulose nanocrystal (CNC) reinforced structural battery electrolyte (CSBE) consisting of CNC, triethylene glycol dimethyl ether (TriG) electrolyte containing a quasi-solid additive, e.g., cyclohexanedimethanol (CHDM), in a vinyl ester polymer. This green and renewable CSBE electrolyte system was in situ polymerized via reaction induced phase transition to form a high performance multidimensional channel electrolyte to be used in structural carbon fiber-based battery fabrication. The effect of various concentrations of CNC on the electrolyte ionic conductivity and mechanical properties was obtained in their relation to intermolecular interactions, interpreted by FTIR, Raman, Li NMR results. Compared to the neat SBE system, the optimized CSBE nanocomposite containing 2 wt % CNC shows a remarkable ionic conductivity of 1.1 × 10^-3 S cm^-1 at 30 °C, which reveals ∼300% improvement, alongside higher thermal stability. Based on the FTIR, Raman, Li NMR results, the content of CNC in the CSBE structure plays a crucial role not only in the formation of cellulose network skeleton but also in physical interaction with polymer matrix, providing an efficient Li⁺ pathway through the electrolyte matrix. The carbon fiber composite was fabricated by 2 wt % CNC reinforced SBE electrolyte to evaluate as a battery half-cell. The results demonstrated that by addition of 2 wt % CNC into SBE system, 7.6% and 33.9% improvements were achieved in specific capacity at 0.33 C and tensile strength, respectively, implying outstanding potential of ion conduction and mechanical load transfer between the carbon fibers and the electrolyte.

Lung organoids and other preclinical models of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fatal disease affecting over 100 000 people in Europe with an increasing incidence. Available treatments offer only slowing of disease progression and are poorly tolerated by patients leading to cessation of therapy. Lung transplant remains the only cure. Therefore, alternative treatments are urgently required. The pathology of IPF is complex and poorly understood and thus creates a major obstacle to the discovery of novel treatments. Additionally, preclinical assessment of new treatments currently relies upon animal models where disparities with human lung biology often hamper drug development. At a cellular level, IPF is characterized by persistent and abnormal deposition of extracellular matrix by fibroblasts and alveolar epithelial cell injury which is seen as a key event in initiation of disease progression. In-depth investigation of the role of alveolar epithelial cells in health and disease has been impeded due to difficulties in primary cell isolation and culture ex vivo. Novel strategies employing patient-derived induced pluripotent stem cells engineered to produce type 2 alveolar epithelial cells (iAEC2) cultured as three-dimensional organoids have the potential to overcome these hurdles and inform new effective precision treatments for IPF leading to improved survival and quality of life for patients worldwide.

The accuracy of computed tomography for clavicle non-union evaluation

BACKGROUND

The primary aim of this study is to determine the accuracy of CT scanning when evaluating non-union of the clavicle.

METHODS

A retrospective review was performed of all CT scans undertaken for suspected nonunion of midshaft clavicle fractures over a 10-year period. The influence of scan timing, callus and patient characteristics was evaluated.

RESULTS

One hundred eighty-four CT scans were analysed. No patient was incorrectly diagnosed with union (n = 85). Ninety-nine scans were reported as non-union with inadequate bridging callus, 19 of which were united at operation or on repeat CT imaging and represented delayed unions. Atrophic callus was found in 57 patients and all of which had a confirmed non-union (positive predictive value 100%). A hypertrophic callus was found in 42 patients, all of the delayed unions were found in this group (positive predictive value for non-union 55%, p < 0.001). CT compared to radiographs showed greater inter-observer agreement for union (weighted kappa 0.75 vs. 0.50 respectively). Overall, CT is 100% sensitive and 81.7% specific for non-union diagnosis.

DISCUSSION

CT has excellent accuracy to determine clavicle union but approximately one in five suspected non-unions went onto unite. Hypertrophic callus finding resulted in a delayed union in approximately half of the cases in our study.

Evolving Strategies for Producing Multiscale Graphene-Enhanced Fiber-Reinforced Polymer Composites for Smart Structural Applications

Graphene has become an important research focus in many current fields of science including composite manufacturing. Developmental work in the field of graphene-enhanced composites has revealed several functional and structural characteristics that promise great benefits for their use in a broad range of applications. There has been much interest in the production of multiscale high-performance, lightweight, yet robust, multifunctional graphene-enhanced fiber-reinforced polymer (gFRP) composites. Although there are many reports that document performance enhancement in materials through the inclusion of graphene nanomaterials into a matrix, or its integration onto the reinforcing fiber component, only a few graphene-based products have actually made the transition to the marketplace. The primary focus of this work concerns the structural gFRPs and discussion on the corresponding manufacturing methodologies for the effective incorporation of graphene into these systems. Another important aspect of this work is to present recent results and highlight the excellent functional and structural properties of the resulting gFRP materials with a view to their future applications. Development of clear standards for the assessment of graphene material properties, improvement of existing materials and scalable manufacturing technologies, and specific regulations concerning human health and environmental safety are key factors to accelerate the successful commercialization of gFRPs.

560 The inclusion of pulmonary arterial pressure misclassifies diastolic function using the current EACVI guidelines in pre-capillary pulmonary hypertension

Background

Pulmonary hypertension (PH) can be pre-capillary or post-capillary (PVH) etiology based on left-sided filling pressures and pulmonary vascular resistance. The 2016 EACVI/ASE Recommendations for the Evaluation of Left Ventricular Diastolic Function (LVDF) provides flow-diagrams to categorize patients. Parameters used include left atrial volume, Doppler-derived transmitral and mitral annular velocities, and systolic PA pressure (sPAP). There are no dedicated criteria to assess the diastolic function in pulmonary arterial hypertension (PAH). Additionally, diseases such as scleroderma can result in both PAH and PVH, thus including sPAP may alter LVDF diagnostic reliability in this population.

Purpose

Because elevated PAP is fundamental to PAH, we hypothesized that the EACVI/ASE diastolic function algorithm has a lower predictive value in correctly classifying diastolic function in scleroderma.

Methodology

We performed a single-center retrospective analysis of scleroderma patients who underwent complete echocardiography and comprehensive right and left heart catheterization for PH evaluation. PH categorization was defined using the 6th World Symposium hemodynamic definitions (PAH as mPAP ≥20 mmHg, PCWP ≤15 mmHg, PVR ≥ 3 WU). Diastolic function categorization used 2016 EACVI/ASE recommendations. Index catheterization and echocardiogram closest to cardiac catheterization were analyzed.

Results

260 patients underwent evaluation and 63 were diagnosed with PH. PAH was diagnosed in 35 (age 64 ±10, mPAP 55± 18 mmHg, LVEF 60 ± 6%) and PVH in 28 (age 65 ± 10, mPAP 34 ± 14 mmHg, LVEF 63 ± 6%). Of the PAH patients, 20 had normal LVEDP (≤ 12 mmHg) and 15 increased LVEDP. In the PAH normal LVEDP patients, the EACVI algorithm classified diastolic function as normal in 25%, grade 2 in 5%, Grade 3 in 5%, and "indeterminate" in 65%. In the PAH group with increased LVEDP (&gt; 12 mmHg), 27% were incorrectly identified as normal, 7% as grade 2 dysfunction, and 66% as indeterminate. The diastolic function algorithm has a sensitivity of 27% and specificity of 75% to diagnose a LVEDP ≤ 12 mmHg, with an AUC of 0.508 (p = 0.91). With exclusion of sPAP from the algorithm, indeterminate cases in both PAH groups were reclassified as normal, resulting in improved sensitivity (93%) but poorer specificity (10%), and a similar AUC (0.517, p = 0.72). In PVH patients, the algorithm performed better with a sensitivity of 63% and specificity of 83% to predict LVEDP &gt; 12 mmHg with AUC 0.773, p = 0.017.

Conclusion

In scleroderma patients with PAH, the EACVI diastolic algorithm performs poorly and is confounded by including PAP as a parameter. The sensitivity of the algorithm is improved by the exclusion of sPAP although with reduced specificity. It remains inadequate to reliably diagnose normal LVEDP. While useful in other populations, algorithm modifications including exclusion of PAP, must be employed in suspected scleroderma PAH.

Geriatric oncology in Spain: survey results and analysis of the current situation

Introduction

Geriatric oncology (GO) is a discipline that focuses on the management of elderly patients with cancer. The Spanish Society of Medical Oncology (SEOM) created a Working group dedicated to geriatric oncology in February 2016.

Objectives

The main goal of this study was to describe the current situation in Spain regarding the management of elderly cancer patients through an online survey of medical oncologists.

Methods

A descriptive survey was sent to several hospitals by means of the SEOM website. A personal e-mail was also sent to SEOM members.

Results

Between March 2016 and April 2017, 154 answers were collected. Only 74 centers (48%) had a geriatrics department and a mere 21 (14%) medical oncology departments had a person dedicated to GO. The vast majority (n = 135; 88%) had the perception that the number of elderly patients with cancer seen in clinical practice had increased. Eighteen (12%) oncologists had specific protocols and geriatric scales were used at 55 (31%) centers. Almost all (92%) claimed to apply special management practices using specific tools. There was agreement that GO afforded certain potential advantages. Finally, 99% of the oncologists surveyed believed it and that training in GO had to be improved.

Conclusions

From the nationwide survey promoted by the Spanish Geriatric Oncology Working Group on behalf of SEOM, we conclude that there is currently no defined care structure for elderly cancer patients. There is an increasing perception of the need for training in GO. This survey reflects a reality in which specific needs are perceived.

Association of Anaesthetists of Great Britain and Ireland: Safe vascular access 2016

Safe vascular access is integral to anaesthetic and critical care practice, but procedures are a frequent source of patient adverse events. Ensuring safe and effective approaches to vascular catheter insertion should be a priority for all practitioners. New technology such as ultrasound and other imaging has increased the number of tools available. This guidance was created using review of current practice and literature, as well as expert opinion. The result is a consensus document which provides practical advice on the safe insertion and removal of vascular access devices.

Cytokine release assays for the prediction of therapeutic mAb safety in first-in man trials--Whole blood cytokine release assays are poorly predictive for TGN1412 cytokine storm

The therapeutic monoclonal antibody (mAb) TGN1412 (anti-CD28 superagonist) caused near-fatal cytokine release syndrome (CRS) in all six volunteers during a phase-I clinical trial. Several cytokine release assays (CRAs) with reported predictivity for TGN1412-induced CRS have since been developed for the preclinical safety testing of new therapeutic mAbs. The whole blood (WB) CRA is the most widely used, but its sensitivity for TGN1412-like cytokine release was recently criticized. In a comparative study, using group size required for 90% power with 5% significance as a measure of sensitivity, we found that WB and 10% (v/v) WB CRAs were the least sensitive for TGN1412 as these required the largest group sizes (n = 52 and 79, respectively). In contrast, the peripheral blood mononuclear cell (PBMC) solid phase (SP) CRA was the most sensitive for TGN1412 as it required the smallest group size (n = 4). Similarly, the PBMC SP CRA was more sensitive than the WB CRA for muromonab-CD3 (anti-CD3) which stimulates TGN1412-like cytokine release (n = 4 and 4519, respectively). Conversely, the WB CRA was far more sensitive than the PBMC SP CRA for alemtuzumab (anti-CD52) which stimulates FcγRI-mediated cytokine release (n = 8 and 180, respectively). Investigation of potential factors contributing to the different sensitivities revealed that removal of red blood cells (RBCs) from WB permitted PBMC-like TGN1412 responses in a SP CRA, which in turn could be inhibited by the addition of the RBC membrane protein glycophorin A (GYPA); this observation likely underlies, at least in part, the poor sensitivity of WB CRA for TGN1412. The use of PBMC SP CRA for the detection of TGN1412-like cytokine release is recommended in conjunction with adequately powered group sizes for dependable preclinical safety testing of new therapeutic mAbs.