bluuebunny/crossref_metadata_2025 huggingface dataset:
129 A task-Based Approach to Nanomaterials Exposure Assessment in the Construction Trades
Authors: West Gavin , Brooks Sara , Burrelli Leonard , Nealley Mark , Saldivar Andreas , Cooper Michael , Lippy Bruce
Published: May 2023

While the critical task of evaluating the hazards of nanomaterials continues, exposure assessments can provide additional information to safeguard workers. The frequent exposure of construction workers to inhalation hazards underscores a pressing need to characterize and quantify nanomaterials in aerosols generated during construction activities. Research was conducted in partnership with affected building trades unions and in collaboration with NIOSH toxicologists to obtain occupationally relevant exposure data. Initial studies took place in a test chamber, in which a skilled tradesperson sprayed or sanded paints and coatings containing ZnO, TiO2, or Ag nanoparticles. The current study, conducted outdoors, investigated exposure to graphene nanoplatelets during cutting, grinding, and tuckpointing of cementitious composites. Personal breathing zone samples were analyzed for elemental carbon (EC) respirable mass concentration and by transmission electron microscopy (TEM) with energy-dispersive x-ray spectroscopy. Wet methods and local exhaust ventilation effectively reduced exposure to graphene; respirable EC was non-detectable when using exposure controls versus up to 3 mg m-3 without. A high proportion of graphene particles observed by TEM were free and not bound to the cement matrix. Compared to the unincorporated graphene, the dimensions of graphene particles observed in air samples were smaller, suggesting a potential physical transformation prior to release from the matrix. Given the dustiness of construction environments, analysis of filter loading prior to collection of TEM samples proved methodologically valuable. These results provide actionable information about exposure risks and controls and support further investigation of the extent to which graphene may alter the toxicity of cement dust.
143 Urinary Metals Exposure and Oxidative Stress Biomarkers in Nanotechnology Workers: Results from the Nanoexplore Project
Authors: Bellisario Valeria , Squillacioti Giulia , Panizzolo Marco , Ghelli Federica , Mariella Giuseppe , Canu Irina Guseva , Bergamaschi Enrico , Bono Roberto
Published: May 2023

Exposure to metal oxides nanomaterials (NMs) might trigger adverse health effects. NMs can generate Oxidative Stress (OS), causing redox effects detectable in urine through suitable biomarkers. We evaluated the cross-sectional association of urinary OS biomarkers with urinary metal concentrations, using data collected in the multicenter international study NanoExplore. One hundred forty-one workers were recruited at three R&D and four industrial facilities employing NMs in different processes (paints/coating[PC];construction chemicals[CC]). Only 129 workers had complete data and, based on the personal work-shift exposure to NMs, they were classified as unexposed workers (n=41), workers with negligible/low exposure (n=37), and with moderate/high exposure (n=51). OS biomarkers (IsoP,MDA,TAP) and metals (27Al,47Ti,52Cr,118Sn) were quantified in urine samples collected before and after exposure monitoring campaign (2-4 work-shifts).  Between-group comparisons were performed with non-parametric tests according to the data distribution. Highly exposed workers had significantly higher pro-oxidant (IsoP and MDA,p<0.005) and antioxidant (TAP,p<0.05) biomarkers concentrations. 47Ti,118Sn and 29Si were significantly higher in CC workers (p<0.005). IsoP and TAP were positively associated with 29Si (both p<0.001), 47Ti (p=0.036,p=0.003), 52Cr (p=0.048,p=0.003) and 118Sn (p=0.047,p=0.022). The ongoing analyses will assess the potential mediation role of OS and metal biomarkers. Occupational exposure to NMs can represent an underestimated hazard for people handling NMs products, increasing OS and potentially beginning pathological processes. Although the health significance of such findings needs to be further elucidated, the assessment of metals in urine may represent a useful tool for estimating the body burden of NMs long-term exposure.
147 Human Lung Organoids Predict Response to Carbon-Based Nanomaterials and Model Pulmonary Fibrosis
Authors: Issa Rahaf , Lozano Neus , Kostarelos Kostas , Vranic Sandra
Published: May 2023

Advances in in-vitro culture systems have stimulated an interest in more reliable testing approaches that predict nanomaterial toxicity. Lung organoids are one example, and display functions consistent with their in-vivo counterparts. Organoids have been used in a variety of applications, but studies have yet to interrogate their suitability for nanomaterial testing. Here, we report the step-wise development of multilineage lung organoids, and validate their potential as tools for predicting pulmonary toxicity of carbon-based nanomaterials. After 50-days of differentiation, the lung organoids exhibited the six major proximal (goblet/basal/club/ciliated) and distal (AECI/II) epithelial cell types of the adult lung. Using microinjection, we developed an exposure model to exploit the airspace-like lumen of the organoids for cargo delivery. We compared the impact of small nanometric (50-950nm, sGO) and large micrometric (4-41µm, lGO) graphene oxide sheets, with multi-walled carbon nanotubes (1-20µm, MWCNT) on lung organoids after 1/7/28d exposure. Consistent with in-vivo data, sGO and lGO exhibited a transient interaction with the alveolar epithelium, and did not induce any histoarchitectural changes indicative of fibrosis. Organoids did however produce 2.5-fold more mucins in response to lGO than sGO exposure, suggesting that a thicker mucin barrier is required to prevent lGO-induced damage. In contrast, MWCNT caused detrimental effects on organoid architecture. Its persistent interaction with the alveolar epithelium led to a pro-fibrotic phenotype, where MWCNT caused AECII to undergo epithelial-mesenchymal transition. With further development, our model may reduce the need for rodent inhalation studies in the assessment of lung toxicity.
156 Nitrogen-Doped Multi-Walled Carbon Nanotubes show Attenuated Pathogenicity in a Mouse Model of Pleural Exposure
Authors: Zacarias-Cabeza Joaquin , Chernova Tatyana , Craxton Andrew , Sun Xiao-Ming , Galavotti Sara , Beier Sina , Self Emily L , Greaves Peter , Poland Craig A , Tsuruoka Shuji , Porter Dale W , Willis Anne E , MacFarlane Marion
Published: May 2023

Engineered carbon nanotubes (CNT) are currently used in many industrial products. Multi-walled carbon nanotubes (MWCNT) exhibit unique physicochemical properties and due to their low density and small size are easily aerosolized, making workplace exposure a potential risk to human health. MWCNT are similar to Asbestos in terms of their high aspect-ratio and thus may pose an asbestos-like inhalation hazard, including sporadic pleural Mesothelioma. Mitsui-7 MWCNT (MWCNT-7) have been classified by IARC as a Group 2B carcinogen. Importantly, physicochemically-altered MWCNT synthesized with nitrogen (MWCNT-ND) have been found to elicit attenuated toxicity; however, their pathogenicity in the pleura is unknown.  Using a mouse model of direct injection into the pleural cavity, we compared the molecular changes that occur at the mesothelium over 20-months following injection with an occupationally-relevant dose of MWCNT-7, MWCNT-ND, Asbestos or carbon black. When compared to Asbestos or MWCNT-7, mice injected with MWCNT-ND did not develop respiratory symptoms. In contrast, in cell lines established from pleural effusions from MWCNT-7 or Asbestos-exposed mice with pre-neoplastic lesions or tumours, Whole-Exome-Sequencing and RNASeq revealed common molecular changes in both lesions and tumours. This identified genes involved in driving progression of pleural inflammatory lesions to Mesothelioma, whereas pre-neoplastic lesion-derived cell lines allow dissection of the hazard mechanism of pathogenic fibres at the molecular level early in disease development and thus may help predict genotoxic potency in exposed human populations.

Our data demonstrate that physicochemical alteration of MWCNT (e.g. synthesis with nitrogen) attenuates pathogenicity and may offer an alternative for use in industrial applications.
37 Functional Requirements to Develop a new Risk Assessment Model for Exposure to Biological Agents
Authors: Colomo Carlota Alejandre , Marchand Geneviève , van der Haar Rudolf , Antiller Cristina Bercero , Viegas Carla , Houba Remko , Zilaout Hicham , Heussen Henri
Published: May 2023

Within Occupational Risk Prevention, the assessment of risks due to exposure to biological agents has received little attention compared to risks such as those arising from chemicals. This was the case until the impact of the COVID-19 pandemic highlighted the importance of health effects related to exposure to biological agents in the work environment. However, the tools for hazard inventory, risk assessment, and implementation of control measures for biological agents are scarce. There are many reasons that make it challenging for OHS professionals to assess the exposure to biological agents such as, little knowledge on the biological agents potentially present in the different economic activities, their effects on health, the lack of standardized methods for quantitative sampling or the lack of reference values available for most biological agents. Different qualitative risk assessment tools for biological agents have been developed over the last decades. Some examples are the Simplified Evaluation of the INSST (Spain), the Biogaval-Neo of the INVASSAT (Spain), the Bioaerosol Tool of the IRSST (Canada) or the RIE Method of the NKAL (The Netherlands). These tools differ from each other in terms of their scope and the parameters used to determine risk and were compared in order to better understand their limitations and applicability. After the comparison was carried out some additional specific parameters have been proposed as essential for the development of this new model. The proposed improvements could be implemented in the development of a new qualitative biological risk assessment model in the Stoffenmanager® tool.
55 Investigating the co-Exposure of Micro(nano)Plastics and Indoor/Outdoor Particulate Matter Using an Alveolar BarrierIn Vitro Model
Authors: Wright Olivia Whittle , Meldrum Kirsty , Doak Shareen H , Wright Stephanie , Clift Martin J D
Published: May 2023

The impact of micro-, nanoplastics (MNPs) and particulate matter (PM) upon human health are escalating concerns worldwide. MNPs released from surgical face masks, and PM from ambient air pollution, can both be inhaled and consequently have potentially significant negative impacts upon human health, particularly on our lung epithelial cell structure and function. Currently, the impact of the realistic co-exposure of these samples is unknown. Therefore, the purpose of this study was to determine the potential inhaled hazardous health effects of the co-exposure of MNPs and ambient (indoor and outdoor) air PM. Using an advanced in vitro testing model combined with a specific mechanistic toxicology approach, it is hypothesised that the co-exposure approach will elucidate important information regarding the differential toxicology of ambient (indoor and outdoor) air PM. The in vitro system will consist of alveolar epithelial type-II cells (-NCI-H441) combined with differentiated monocytes (dTHP-1), cultured at the relevant in vivo ratio and at the air-liquid interface. Cell cultures will be exposed for both 4 and 24hrs to MNP (commercially available polypropylene (PP) and blue face mask extracted PP), PM (NIST 2584 and NIST 1649a respectively) and then subsequent MNP+PM (both NIST 2584 and NIST 1649a respectively) via aerosol (VITROCELL Cloud12), using alternative dosimetry patterns. The biochemical endpoints of cytotoxicity, oxidative stress, (pro-)inflammatory response and genotoxicity, will then be assessed to provide the basis for future global analytical techniques to examine the currently unknown human hazard of inhaled MNPs (+/- PM).
57 Particles in Outdoor Air: are they all Equal?
Authors: Miller Mark , Clift Martin , Harrison Roy , Kelly Frank , Doutsi Artemis , Mitsakou Christina , Earl Naomi , Exley Karen , Gowers Alison
Published: May 2023

Statement from the Committee on the Medical Effects of Air Pollutants (COMEAP) on the differential toxicity of particulate matter according to source or constituents

Particulate matter in outdoor air comes from a wide range of different sources and contains many different chemical components. Understanding which of these sources and components are particularly harmful would help to focus policies and interventions to reduce impacts on health. COMEAP recently (July 2022) published an updated statement on this topic, drawing on recent reviews of the available evidence. It noted that particulate matter, and constituents of particulate matter, associated with combustion and road traffic have received the most research attention. However, there was insufficient coherence in the epidemiological evidence to conclude that these sources of particulate matter play a significantly greater role in the health effects of particulate air pollution than other sources or constituents. A comprehensive review of the evidence reveals that toxicity has been attributed to a wide variety of constituents and sources, possibly acting by a number of different mechanisms. However, the complexity of sources, sizes and chemical composition of particulate matter makes it extremely difficult to identify which characteristics of particles might make them less harmful or more toxic than others.  Future research assessing the influence of chemical composition of particulate matter should offer greater insights into toxicity. But, at present, PM2.5 (the mass concentration of fine particulate matter in air) remains the most suitable metric for evaluating health impacts and regulating particulate air pollution.
2 Humanising Nanotoxicology Testing: Moving Towards Animal-free Approaches for Hazard Assessment of Nanomaterials
Authors: Pokorski Pawel , Stone Vicki , Murphy Fiona
Published: May 2023

The vast array of nanomaterials (NMs) under development raises ethical concerns over the reliance and extent of animal usage in the hazard assessment of substances. Grouping which allows read-across of data from NMs predicted to pose similar hazard could provide justification for waiving of in vivo tests. The GRACIOUS Framework has defined Integrated Approaches to Testing and Assessment (IATAs) to guide the generation of data to support grouping. Each IATA is underpinned by a tiered testing strategy promoting the use of acellular and in vitro assays, (Tier 1-2), which are predictive of in vivo mechanisms of toxicity. Tier 3 in vivo studies are only required to confirm grouping or fill specific gaps. Adopting the IATA approach allows the effective triage of vast number of NMs prioritized for in vivo hazard assessment, thus reducing overall animal testing. However, many of the methods recommended at Tier 1-2 are reliant on the use of animal-derived materials and reagents. The information gathered at early Tiers therefore cannot be considered animal-free unless adaptions are made to standard in vitro protocols to replace all animal-derived reagents. The objective of this study was to review the GRACIOUS Inhalation IATA and identify where animal-free options could be selected when designing experimental hazard studies. The replacement of animal-derived reagents with human alternatives was trialed in multiple Tier 1 assays using a CuO NM as a case study material. This proof-of-concept study informs the suitability of animal-free methods for NM hazard assessment and demonstrates only minor adaptions may be required.
66 Sugarcane Ash and Sugarcane Ash-Derived Silica Nanoparticles Alter Mitochondrial Function and Metabolic Activity in Human Proximal Tubular Kidney Cells
Authors: Stem Arthur , Rogers Keegan , Roncal-Jimenez Carlos , Johnson Richard , Brown Jared
Published: May 2023

Multiple epidemics of chronic kidney disease of an unknown etiology (CKDu), primarily in young healthy agricultural workers, have emerged in agricultural communities around the world. We have hypothesized that the harvest and burning of sugarcane leading to inhalation of sugarcane ash may contribute to development of CKDu. Sugarcane stalks consist of ~80% amorphous silica and we have demonstrated that following burning of sugarcane, nano-sized silica particles (~200nm) are generated. To determine what effect such exposures have on kidney cells, a human proximal convoluted tubule (PCT) cell line (HK-2) was subjected to treatments ranging in concentration from 0.025µg/mL to 25µg/mL of sugarcane ash, desilicated sugarcane ash, sugarcane ash-derived silica nanoparticles (SAD SiNPs), or manufactured pristine 200nm silica nanoparticles. Following 6 to 48 hours of exposure, mitochondrial activity and viability were found to be significantly reduced when exposed to SAD particles at concentrations 2.5µg/mL or higher. Oxygen consumption rate (OCR) and pH were investigated with a Seahorse XF Analyzer, revealing significant changes to cellular metabolism across treatments as early as 6 hours following exposure. While most treatments slightly increased respiration, SAD SiNPs were found to inhibit mitochondrial function, reduce ATP generation, increase reliance on glycolysis, and reduce glycolytic reserve. Metabolomic analysis following 24 hours of exposure found several cellular energetics pathways (e.g., fatty acid metabolism, glycolysis, and TCA cycle) significantly altered across ash-based treatments. Such changes indicate that exposure to sugarcane ash and its derivatives can promote mitochondrial dysfunction and disrupt metabolic activity of human PCT cells.
68 On the Role of Chemical Identity over the size of Model Ultrafine Particles Driven (geno)-Toxicity
Authors: Pantzke Jana , Das Anusmita , Zimmermann Elias J , Offer Svenja , Jeong Seongho , Delaval Mathilde N , Schnelle-Kreis Jürgen , Sklorz Martin , Bucchianico Sebastiano Di , Zimmermann Ralf
Published: May 2023

Especially through the release from anthropogenic sources, there is growing concern about human exposure to ultrafine particulate matter (UFP). Inhalation of UFP is associated with respiratory diseases such as asthma, pulmonary fibrosis and lung cancer, but their mechanisms of action are still vastly unknown. In this study we aimed to address the question whether the physical characteristics of UFP contribute most to their toxicity or whether the particles primarily act as carriers of toxic chemicals. For this scope, two distinct UFP aerosols with low or high content of semi-volatile organic compounds (SVOC) but comparable sizes were produced by a combustion aerosol standard soot generator and investigated regarding their acute (geno)-toxic potential in a cell model consisting of alveolar epithelial cells, macrophages, and fibroblasts at the air-liquid interface. Low SVOC UFP induced an increased cytotoxicity accompanied by a reduced cell number of epithelial cells and a decreased metabolic activity of fibroblasts. Furthermore, an increased intracellular release of reactive oxygen species (ROS) was observed after low SVOC UFP treatment, which resulted in a depletion of intracellular glutathione. The increased ROS release could be causative for the observed secondary genotoxicity in fibroblasts exclusively detected after exposure to low organic content UFP. High SVOC UFP did not impact cell viability, but an increased DNA damage could be detected in epithelial cells. All in all, UFP with low organic content seem to induce a stronger acute cytotoxic and oxidative stress response in epithelial cells, which might cause secondary effects in fibroblasts.
70 Inhalation Exposure of Copper Particles - Quantitative Differentiation Between Copper Oxides and Metallic Copper
Authors: Bluemlein Katharina , Schirmer Thorben , Licht Oliver , Schuchardt Sven
Published: May 2023

Inhalation exposure to copper and its inorganic compounds can occur in various industrial sectors such as ore mining, production of electrical equipment etc. Toxic effects of copper and its oxides have been shown to be attributed to i. particle size and ii. dissolution/release of copper ions. The latter being dependend on the chemical composition of the copper particle and its size. Hence, in the context of occupational inhalation exposure to those compounds emphasis should not only be directed towards particle size but also to the copper species. We have developed an ICP-MS based method that allows quantitative distinction between copper oxides (CuxO) and metallic copper (mCu) upon sampling on mixed-cellulose ester (MCE) membrane filters. This approach is based on the different dissolution properties of CuxO and mCu in dilute acid. Systematic assessment of the approach in regard to filter load and extraction time have been conducted and successfully applied to field samples.
84 Bugs and our Airways: Successful Development and Evaluation of a School Outreach Project
Authors: Marczylo Emma , Macchiarulo Sameirah , Bowsher Rachel , Goode Emma-Jane
Published: May 2023

Increased awareness of air pollution and its potential health impacts has led to many national and international ‘clean air’ initiatives. However, what do we really mean by ‘clean air’? While the recent pandemic has highlighted the consequences of infectious disease, many remain less aware of the impact biological airborne particles (so-called bioaerosols) can have on non-communicable diseases such as allergy and asthma. This project aimed to improve children’s understanding of bioaerosols and their positive and negative associations with airway and lung health.  We trialled three sessions over a three-week period in primary school children aged 10-11 years to discuss bioaerosols and health within an engaging and educational framework, with the added benefit of promoting STEM and inspiring them to think about the range of careers within environmental science and public health. Sessions included a mixture of presentations and interactive activities. At the end of each session, we conducted evaluation sessions with both students and teachers. Children engaged well with the subject material, enthusiastically contributed to discussions and activities, and provided useful feedback for further improvements. They particularly enjoyed the hands-on activities and demonstrations, and the teacher commented that the sessions complemented the curriculum by linking new concepts to existing knowledge. This project encouraged two-way engagement between multidisciplinary researchers, teachers and children to develop engaging, fun and educational activities. This will provide a legacy of resources and expertise to expand across the wider schools’ networks, building excellent public engagement capacity and capability.
91 Development of Methods for Exposure- and Risk Assessment of Graphene
Authors: Storsjö Tobias , Sun Jinhua , Tinnerberg Håkan , Farbrot Anne
Published: May 2023

The purpose of this work is to evaluate the Organic carbon/elemental carbon technique as a method to quantify and identify the exposure of graphene and its derivatives, the aim being to propose a standardized occupational exposure measurements method for graphene. Graphene is a 2D-material consisting primarily of elemental carbon, and has many useful properties such as flexibility, elasticity, and conductivity among others. Graphene could therefore become a material used in many occupational fields in the future, and as of today, no optimal measuring technique for occupational exposure exists. The readily available techniques are either nonspecific or nonquantitative. An OC/EC-instrument can quantitively determine the amount of and distinguish between two different types of carbon, organic and elemental carbon. OC/EC could therefore be a possible measuring method used to quantitively determine occupational exposure to graphene. Preliminary test of the method has shown that it is possible to determine the amount of graphene on a quartz filter using the technique. Early results have also shown that it is possible to pinpoint which type of graphene that has been analysed between, graphene oxide, reduced graphene oxide and graphene. The technique needs optimization, but early results indicates that the technique could be a fast and efficient monitoring technique.
107 Assessment of in Vitro Toxicity of Inhalable Incidental Nanoparticles Originating in the Ceramic Industry
Authors: Martín Verónica Moreno , López Maria , Fraga Sonia , Sanfélix Vicenta , Viana Mar
Published: May 2023

Assessing exposure to nanomaterials in industrial workplaces is a widespread challenge. Nanoparticle release was evaluated, under real-world operating conditions, in one thermal spraying and one tile firing facility. Nanoparticles were characterised in terms of mass and number concentrations (µg/m3; /cm3), particle size distribution, chemical composition and morphology, and in vitro toxicity. The present work targets especially the toxicological characterisation of the aerosols sampled. Particles <2 microns in size were sampled in cell-culture medium using an SKC Biosampler connected to a pump operating at 12 lpm. Samples were conserved frozen at -20ºC until analysis. Submerged-cell cultures using the commercially-available A549 cell line were used for the in-vitro assays, where cell viability and generation of reactive-oxygen species (ROS) were assessed. Preliminary results evidenced a relatively large variability across samples in terms of cell viability, with reductions ranging between <5% and up to 60% after 2-hour exposures. Results suggested that the initial INP concentration in the samples may play a relevant role in the results, as in highly concentrated samples nanoparticles may interfere with the cellular uptake of the Alamar Blue dye used and, subsequently, on fluorescence results. ROS generation was detected increasingly over time during the test period (1-4 hours). Readings obtained after 3-4 hour became mostly stable. Finally, these results provide the baseline for the subsequent assessment of the expected reduction in INP concentrations and toxicity resulting from the implementation of risk mitigation measures, which will focus on a custom-designed air filtration system developed in the framework of this project.
136 Lung Clearance Kinetics and Biotransformation of Iron Oxide Nanoparticles: the Role of Particle Dissolution
Authors: Jeong Jiyoung , Cho Wan-Seob
Published: May 2023

It has been recognized that toxicological data such as kinetics and mechanism of action play a key role to understand toxicity of nanoparticle comprehensively, It has become more and more important to study kinetics and mechanism of action. Although there have been many reports regarding the toxicokinetics or toxic mechanism based on physicochemical properties, further research is still required to elucidate the toxic effect of nanoparticles. Here, we investigated the impact of particle dissolution on clearance kinetics and biotransformation using two types of nanoparticles (Fe2O3NPs, TiO2NPs; a reference material for poorly soluble nanoparticle) in rats upon intratracheal instillation. Quantitative analysis of lung burden by ICP-OES and time-course observation of particle morphological transformation by TEM were performed at 0 h, 1, 7, 14, 30, and 90days post-treatment to evaluate the lung clearance kinetics and biotransformation. As a result, Fe2O3NPs showed relatively rapid clearance from the lung with two phases, while TiO2NPs showed prolonged retention in the lung with one phase. Under TEM observation of Fe2O3NPs and TiO2NPs recovered from the lung tissues, no significant morphological changes were observed for TiO2NPs at any time points during the study. However, morphological changes of Fe2O3NPs occur, in particular at later time points (7, 14, 30 and 90 d), which is assumed particle dissolution affect morphological transformation. These findings would provide additional information on lung clearance kinetics and biotransformation of Fe2O3NPs and TiO2NPs for better understanding the relationship between particle dissolution and particle clearance.
137 Analysis of Debris Generated During the Process of Cutting and Grinding of Carbon Fibers-Reinforced Plastics
Authors: Kumoi Jun , Ikegami Akihiko , Fujitani Yuji , Ichihara Gaku , Yano Takeo , Ichihara Sahoko
Published: May 2023

Carbon fiber reinforced plastics (CFRP) is a leading functional material with superior strength and low mass density compared to metal. Recently, due to its excellent property, it has spread to a wide range of fields from sporting goods, such as golf clubs and fishing rods, to aerospace products. However, there is concern that debris (microparticles) is easily released in the processing process of CFRP. The present study investigated the ambient level, size, and shape of particles generated from CFRP during various machining processes in an occupational setting. The size and shape of particles were observed using scanning electron microscopy (SEM) and their chemical compositions were also analyzed using energy dispersive spectroscopy (EDS). The majority of debris from CFRP was cylindrical with a diameter comparable to the diameter of the original carbon fiber, suggesting transversally split carbon fiber. However, some of the debris was fibrous, length >5 μm, width 3, suggesting longitudinally split carbon fiber. These fibrous fragments were morphologically compatible with the WHO definition of respirable fibers. The particles in the working environment were also monitored with a real-time monitoring device, NanoScan SMPS Model 3910. Measurement by real-time monitoring device showed that not only microparticles but also smaller particles were released in the processing process of CFRP. These particles are probably breakdown elements of the epoxy thermoset polymer (resin) in CFRP. The potential hazard of debris from CFRP in the processing process in an occupational setting and risk assessment is needed for the safe handling of CFRP.
145 Cumulative Occupational Exposure to Nanoparticles, Inflammatory Biomarkers and Respiratory Health in the Nanoexplore Cohort
Authors: Squillacioti Giulia , Garzaro Giacomo , Charreau Thomas , Wild Pascal , Bellisario Valeria , Panizzolo Marco , Antonello Giulia , Bono Roberto , Bergamaschi Enrico , Guseva-Canu Irina
Published: May 2023

Exposure to nanomaterials (NMs) may harm biological systems by altering the redox status and triggering inflammatory processes, which in turn may affect respiratory health. In the NanoExplore cohort of 141 workers, we observed a positive dose-response relationship between the short-term exposure to NMs and biomarkers of inflammation, measured in Exhaled Breath Condensate (EBC), but no relationship with lung function parameters (LFP). This study focuses on the association between cumulative exposure to NMs over the last 10 years and changes in LFP and the potential mediating role of airways inflammation. Individual cumulative exposure was estimated by multiplying the nanoparticle concentration, measured at workers’ workstations by DiSCmini, by the duration of worker’s employment at the corresponding workstation up to last 10 years. In EBC, we measured High-Sensitivity CRP (Hs-CRP), IL-1β, TNF-α, and IL-10 as biomarkers of inflammation. LFP were assessed according to ATS/ERS standards. Their association with cumulative exposure was examined using logistic regression models adjusted for tobacco consumption (in pack-years), among 136 workers with complete data (19-62 yrs., 70% males). We found that per unit increase in 10-year exposure, the risk of observing FEV1 values below the normal limit increases by 0.3% (95%CI: 1.000-1.005, p=0.049) and by 0.8% (95%CI: 1.000-1.015, p=0.039) with the exposure expressed as number of particles and lung deposited surface area, respectively. The ongoing mediation analysis will investigate the potential mediating role of inflammation in the association between cumulative exposure to NMs and lung function
152 Top-down Preparation and Characterization of Crystalline Nanosilica for Toxicological Investigations
Authors: Bellomo Chiara , Pavan Cristina , Fiore Gianluca , Escolano-Casado Guillermo , Mino Lorenzo , Turci Francesco
Published: May 2023

Crystalline silica (CS) is a well-known human carcinogen and freshly fractured CS is strongly held to be more toxic than aged dust. Mechanical fracturing indeed generates on CS surface a specific family of Nearly-Free Silanols (NFS), a moiety that was proved to destabilize cell membranes and initiate inflammation in vivo. During milling, silica nanoparticles are also generated, however their contribution to the overall toxicity of quartz is still largely unexplored. Nanoquartz can be synthetized via bottom-up methods, but the surface chemistry of those crystals strongly differs from nanoparticles resulting from fracturing. We report here a top-down milling procedure to obtain a nanometric quartz that shares with fractured quartz the key surface properties relevant to toxicity. Fracturing procedure was optimized by coupling dry and wet milling steps, using water as a dispersing agent, and varying milling times and rotational speeds. We obtained a set of samples that would be classified as nanomaterials under EU CLP regulation (>50% of particles in number are < 100 nm) and exhibited a strong tendency to form submicrometric agglomerates. Deagglomeration with surfactants or simulated body fluids was negligible. Partial lattice amorphization and bimodal crystallite domain size were observed, as confirmed by the presence of two distinct domains of scattering with nanometric (< 50 nm) and submicrometric (0.8-1 µm) crystallite size. A moderate membranolytic activity, which nicely correlated with the amount of surface NFS, signalled that our nanoquartz may induce inflammation in vivo. Overall, a membranolytic nanoquartz for investigating the toxic activity of nanometric silica was obtained.
A rapidly evolving cricket produces percussive vibrations: how, who, when, and why
Authors: Wikle Aaron W , Broder E Dale , Gallagher James H , Tinghitella Robin M
Published: May 2023

Sexual signals are often transmitted through multiple modalities (e.g., visual and chemical) and under selection from both intended and unintended receivers. Each component of a multimodal signal may be more or less conspicuous to receivers, and signals may evolve to take advantage of available private channels. We recently documented percussive substrate-borne vibrations in the Pacific field cricket (Teleogryllus oceanicus), a species that uses airborne acoustic and chemical signals to attract and secure mates. The airborne signals of Hawaiian T. oceanicus are currently undergoing rapid evolution; at least five novel male morphs have arisen in the past 20 years. Nothing is yet known about the newly discovered percussive substrate-borne vibrations, so we ask “how” they are produced, “who” produces them (e.g., population, morph), “when” they produce them (e.g., whether they are plastic), and “why” (e.g., do they play a role in mating). We show that the vibrations are produced exclusively by males during courtship via foreleg drumming. One novel morph, purring, produces quieter airborne songs and is more likely to drum than the ancestral morph. However, drumming behavior is also contextually plastic for some males; when we removed the ability of males to produce airborne song, ancestral males became more likely to drum, whereas two novel morphs were equally likely to drum regardless of their ability to produce song. Opposite our prediction, females were less likely to mate with males who drummed. We discuss why that might be and describe what we can learn about complex signal evolution from this newly discovered behavior.
High-quality, customizable heuristics for RNA 3D structure alignment
Authors: Zurkowski Michal , Antczak Maciej , Szachniuk Marta
Published: May 2023

Motivation

Tertiary structure alignment is one of the main challenges in the computer-aided comparative study of molecular structures. Its aim is to optimally overlay the 3D shapes of two or more molecules in space to find the correspondence between their nucleotides. Alignment is the starting point for most algorithms that assess structural similarity or find common substructures. Thus, it has applications in solving a variety of bioinformatics problems, e.g. in the search for structural patterns, structure clustering, identifying structural redundancy, and evaluating the prediction accuracy of 3D models. To date, several tools have been developed to align 3D structures of RNA. However, most of them are not applicable to arbitrarily large structures and do not allow users to parameterize the optimization algorithm.

Results

We present two customizable heuristics for flexible alignment of 3D RNA structures, geometric search (GEOS), and genetic algorithm (GENS). They work in sequence-dependent/independent mode and find the suboptimal alignment of expected quality (below a predefined RMSD threshold). We compare their performance with those of state-of-the-art methods for aligning RNA structures. We show the results of quantitative and qualitative tests run for all of these algorithms on benchmark sets of RNA structures.

Availability and implementation

Source codes for both heuristics are hosted at https://github.com/RNApolis/rnahugs.
O004 Impact of normothermic regional perfusion on recipient outcomes after simultaneous pancreas and kidney transplantation – a UK analysis from the NHSBT Pancreas Advisory Group
Authors: Owen R , Counter C , Tingle S , Simmonds L , Callaghan C , Casey J , Currie I , Drage M , Elker D , Manas D , Muthusamy A , Oniscu G , Pettigrew G , Sinha S , Sutherland A , Van Dellen D , Watson C , Wilson C , White S
Published: May 2023

Introduction

A quarter of UK SPK transplants are from Deceased Cardiac Donors(DCD), with an increasing number recovered following in-situ normothermic regional perfusion(NRP). The aim of this study was to review the UK experience of SPK transplantation following NRP in DCD.

Methods

Data were collected on all first DCD SPKTs(n=360) performed during 2013–2021 from the UK Transplant Registry. Non-NRP DCD SPK were compared to NRP DCD SPKs. Kaplan Meier plots and cox regression analyses were performed.

Results

Some 198 pancreas were offered from NRP donors with 83 being retrieved. The majority of SPK grafts were from nonNRP donors n=324(90.0%) with n=36(10.0%) from NRP donors. The median cold ischaemic time (CIT) from NRP donors (9.7 hours) was significantly less than nonNRP donors (10.2 hours) (p=0.013). For all other parameters, donors were well matched. Recipients who received a graft from an NRP donor were also well matched with the recipients who received a graft from a nonNRP donor. Univariate analysis showed no statistically significant difference in one-year pancreas graft (NRP 97.2%, non-NRP 89.2%, p=0.145), kidney graft (NRP 100%, nonNRP 95.9%, p=0.221) or patient survival (NRP 100%, nonNRP 98.3%, p=0.442) despite an increasing trend in favour of NRP SPK.

Conclusions

This is the largest reported analysis of NRP for SPK transplants to date. NRP has previously been shown to be beneficial for liver transplants. Despite some concerns that NRP may preferentially benefit the liver at the expense of other organs our study has shown no adverse effects. Larger studies are needed to evaluate whether NRP improves graft utilisation rates for SPK.
O005 Perturbations in gut microbial metabolites promotes a pro-inflammatory state increasing risk of acute rejection post renal transplantation
Authors: Chang F , Vaitkute A , Attrill M , Chong S , Mahdi H , Blair P , Salama A , Mauri C , Eaton S , Bajaj-Elliott M , Pesenacker A , Motallebzadeh R
Published: May 2023

Introduction

Emerging evidence suggests that the gastrointestinal microbiota-immune axis impacts on extra-intestinal health. We aim to identify the influence of microbial metabolites on recipient's immunity; testing the hypothesis that reduced availability of bacterial-derived metabolites associated with immunoregulation e.g., short chain fatty acids (SCFAs) and tryptophan-derivatives promote a pro-inflammatory state increasing risk of acute rejection (AR).

Methods

Ninety recipients and 21 live-donors were recruited with urine, stool and blood samples collected at baseline and up to 12-months after surgery. Flow cytometry was used to assess for circulating subpopulations of CD19+ B-cells and CD4+ T cells (cTFH - CD3+CD4+CD45RA-CXCR5+ and cTFR -CD3+CD4+CXCR5+FoxP3+). Faecal SCFAs and indole derivatives were identified by mass spectroscopy and high-performance liquid chromatography.

Results

Patients with AR had an almost 10-fold reduction of FoxP3+ cTFR cells after transplantation compared to baseline (p=0.03). There were lower frequencies of cTFR cells at 3-months when compared to matched recipients without AR (0.009%±0.014% vs 0.10%±0.12%; p=0.01). In AR, there was a trend for higher frequencies of plasmablasts, resting memory B-cells and TFH cells at baseline, with fewer transitional B-cells at 3-months. Despite tryptophan availability increasing after transplantation, patients with AR displayed reduced levels of SCFAs at 1-month.

Conclusion

Complex changes in microbial metabolites exist after transplantation that may influence the balance of cTFH vs cTFR cells. Despite increase in dietary tryptophan, recipients with AR may harbour gut microbes that are unable to metabolise tryptophan into immune-regulatory metabolites, which predisposes a pro-inflammatory immune state.
O007 Glycaemic variability is a predictor of graft failure following infra-inguinal bypass for peripheral arterial disease (PAD). A retrospective cohort study
Authors: Farndon D , Bennett P , Nunney I , Dhatariya K
Published: May 2023

Introduction

Many factors influence graft patency following infra-inguinal bypass (IIB). Glycaemic variability (GV) is associated with increased risk of multiple adverse outcomes. However, the impact of GV on outcomes following IIB is unknown.

Methods

A 3-year single centre retrospective case notes analysis of all people undergoing IIB between 2017–2019. Rutherford stage, graft conduit, bypass level, procedure details, baseline demographics, co-morbidities, mean HbA1c and GV (HbA1c SD) were assessed. Time to re-intervention, ipsilateral amputation or death were recorded to determine primary (PP).

Results

Were reported as hazard ratios (HR) following multivariate adjustment.193 IIB outcomes were analysed: mean (±SD) age 68.9(9.2) years; 135(69.9%) male. 156 (80.8%) had pre-operative HbA1c for analysis and 88(45.6%) had DM; 87(45.1%) were current smokers; 107(55.4%) underwent emergency procedures. Those without diabetes were more likely to smoke (P=0.011), but those with DM were more likely to have IHD (0.007), had higher Rutherford stage (p=0.0006), underwent more distal bypasses (p=0.004) and more emergency procedures (p=0.04). GV>9.1% was associated with significantly lower PP than GV<9.1%, 198 [105–377] vs. 713 [313-1287] days (p=0.02). Univariate predictors of PP included Rutherford stage 4 vs 3 (p=0.01), level of bypass, (p=0.0003), DM (p=0.04) and GV>9.1% (p=0.02). On multivariate adjustment, GV >9.1% and level of bypass remained independent predictors of primary patency, HR 1.96 (95% CI:1.12-3.42, p=0.018) and HR 2.54 (95%CI:1.24-5.22, p=0.038) respectively.

Conclusion

We have demonstrated GV and level of bypass as independent predictors of graft failure on multivariate analysis. Therefore, optimising GV should be a therapeutic target to improve outcomes.
O009 Completion of supervised exercise therapy improves outcomes for patients with intermittent claudication: propensity score-matched analysis of 7-year outcomes
Authors: Ravindhran B , Lim A , Walshaw J , Kurian T , Sidapra M , Lathan R , Hitchman L , Mohamed A , Carradice D , Smith G , Chetter I , Pymer S
Published: May 2023

Introduction

The goal of this study was to compare the long-term outcomes of patients with intermittent claudication (IC) who completed supervised exercise therapy (SET) versus patients who either declined or prematurely discontinued SET.

Methods

A retrospective, observational, single-centre cohort study of patients with IC referred to SET. Outcomes included progression to chronic limb-threatening ischemia (CLTI), revascularization requirement, and cardiovascular death.1:1 propensity score matching (PSM) using nearest-neighbour (caliper=0.2) was performed. Multivariate analysis (MVA) and logistic-regression (LR) were used to identify significant effect modifiers to guide PSM. Time-to-event data were analysed using Kaplan-Meier survival analysis.

Results

241 patients were referred to SET between July 2015 and July 2016. Forty-nine patients completed SET and 192 patients did not. There was no significant difference in age, diabetes, smoking-cessation, and medication compliance between groups. After PSM, 49 patients who declined SET and 41 patients who completed SET were analysed. Progression to CLTI was significantly lower (10.2% vs 65.9%; p<0.001) in patients who completed SET. There was also a significant difference (p<0.001) in the median time to develop CLTI (1952 days [IQR 151;95% CI:1655 to 2249] vs 858 days [IQR 282; 95% CI:305 to 1411]). Revascularisation requirement: SET completion was associated with a significantly lower incidence of revascularisation (42.5% vs 57.5%; p=0.04) and a lower number of revascularization procedures SET(p<0.001). SET completion significantly delayed revascularization (1158 days [IQR 131;95% CI:931 to 1443] vs 326 days [IQR 38;95% CI:252 to 400]; p=0.03). There was no significant difference in the incidence (26% vs 35%; p=0.4) or time to cardiovascular death.

Conclusion

SET for claudication reduces requirement for future revascularisation by slowing disease progression.
O010 A novel microfluidic immunoassay for in-solution quantification of alloantibody affinity and concentration in transplantation and beyond
Authors: Priddey A , Karahan G , Schneider M , Meisl G , Scheidt T , Xu C , Peacock S , Buchli R , Mulder A , Heidt S , Class F , Knowles T , Kosmolipaptsis V
Published: May 2023

Introduction

Antibody characterisation is fundamental in transplantation and infectious diseases, but current immunoassays cannot determine two fundamental antibody properties, affinity (KD) and concentration ([Ab]). We aimed to overcome these limitations to allow in-depth profiling of antibodies directly in sera and provide insights into clinical translation.

Methods

Using a microfluidic diffusional sizing-based strategy, we developed microfluidic antibody affinity profiling (MAAP), a novel in-solution immunoassay that simultaneously determines KD and [Ab] directly in serum. MAAP was developed and validated using the HLA-alloantibody system and applied in HLA Ab-incompatible (HLAi) transplantation and in anti-SARS-CoV-2 immunity.

Results

MAAP enabled quantification (KD and [Ab]) of alloantibody-HLA interactions in both purified and alloantibody-spiked sera. We demonstrated that transplant single-HLA-bead (SAB) immunoassays were avidity and [Ab]-dependent, cellular immunoassays (flow-cytometry and complement-dependent-cytotoxicity) were KD and [Ab]-dependent, antibody-mediated cytotoxicity was proportional to antibody-HLA KD, and micromolar antibody-HLA interactions were functionally insignificant despite high SAB signal. In HLAi transplants, MAAP differentiated clinically significant donor-specific-alloantibodies (leading to rejection) from those tolerated despite similar SAB assay output and provided insights into memory re-activation and immune-monitoring post-transplantation. In SARS-CoV-2, MAAP showed wide variation in anti-RBD antibody KD in convalescent sera (n=34), good correlation with serum neutralisation capacity (p<0.001), and evidence of affinity maturation 3-months post-infection (despite [Ab] reduction). In vaccinated sera (n=17), anti-RBD antibody KD was significantly weaker against Omicron than wild-type (p<0.001), providing insights into variant immune-escape strategies.

Conclusion

This work outlines a path towards in-depth antibody profiling and demonstrates the importance of antibody abundance and affinity in clinically relevant humoral immunity.