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Journal articleWagner M, Biegler V, Wurm S, et al., 2025,
Pulp fibre foams: Morphology and mechanical performance
, Composites Part A: Applied Science and Manufacturing, Vol: 188, ISSN: 1359-835XCellulose (pulp) fibre foams serve as bio-based alternative to fossil-based cellular lightweight materials. The mechanical properties of cellulose fibre foams are inferior compared with traditional polymer foams and available information is often limited to compression properties. We present a comprehensive analysis of cellulose fibre foams with densities ranging from 60 to 130 kg/m3, examining their compression, tensile, flexural, and shear properties. Key findings include a high mean zenithal fibre angle which decreases with increasing density, as well as a high strain rate amplification (SRA) in compressive strength, which also decreases with increasing density. With respect to formulation, the addition of carboxymethyl cellulose (CMC) enhanced fibre dispersion, bubble homogeneity of the wet foam, and dimensional stability of the end-product. These results provide a foundation for numerical models and advance the understanding of cellulose pulp fibre foams, highlighting their potential for certain applications.
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Journal articleOrzan E, Barrio A, Biegler V, et al., 2025,
Foaming and cross-linking of cellulose fibers using phytic acid
, Carbohydrate Polymers, Vol: 347, ISSN: 0144-8617Bio-based compounds have become the focus in the development of next-generation materials. The polyphosphated structure and availability of phytic acid has sparked an interest to understand its properties and apply it to making fire-retardant fabrics. However, its degradative effect on natural fibers sets limitations to its potential uses. In this study, we unveiled a new dimension to explore with phytic acid: cellulose fiber foams. Phytic acid enabled synergistic foaming with carboxymethyl cellulose albeit causing issues in long-term wet foam stability. Adding cellulose fibers to this mixture and drying at 160 °C produced solid foams with increased compressive strength and stiffness; comparable to foams cross-linked with the commonly used citric acid. The reduced contact area in low-density fiber networks allowed the cross-linking between phytic acid and the fiber network to mitigate structural weakening due to fiber degradation. Imaging also revealed the formation of a film encompassing fiber bonds; attributed to the strong interaction between phytic acid and carboxymethyl cellulose. Furthermore, phytic acid imparted self-extinguishing fire-retardant properties to the cellulose fiber foams measured using thermogravimetric analysis and cone calorimetry. This work showcases a simple new application for phytic acid without the use of catalysts or solvents. It serves to encourage further development of green practices to continuously challenge the industrial landscape.
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Journal articleBiegler V, Verdross P, Woodward RT, et al., 2024,
Cellulose fibre foam templated porous epoxy composites: Wetting matters
, Composites Part A: Applied Science and Manufacturing, Vol: 187, ISSN: 1359-835XCellulose foams were used to produce porous epoxy-composites. The influence of fibre wetting by the resins on foam morphology and resulting compression properties was investigated. Impregnated foam morphology determined the composite structures and their mechanical properties. Fibre preforms of various densities (40–80 kg·m−3) were prepared by frothing surfactant stabilised fibre suspensions. The preforms, exhibiting compressive strengths of 0.02 MPa, were impregnated with three different resins (a lignin-based resin BLER/MA, and two commercial formulations, A/A and A/XB). Depending on the formation of closed- or open-cell structures in the cured foam composites, compressive strengths of up to 2 MPa (BLER/MA), 33 MPa (A/A), or 23 MPa (A/XB), and compressive moduli of up to 47 MPa (BLER/MA), 468 MPa (A/A), or 379 MPa (A/XB) were obtained. The surface area, fibre coverage homogeneity, and composite morphology were investigated in relation to wetting. A tool kit for fibre foam templated porous composite design is provided.
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Journal articleDomingo-Sabugo C, Willis-Owen SA, Mandal A, et al., 2024,
Genomic analysis defines distinct pancreatic and neuronal subtypes of lung carcinoid.
, J Pathol, Vol: 264, Pages: 332-343Lung carcinoids (L-CDs) are rare, poorly characterised neuroendocrine tumours (NETs). L-CDs are more common in women and are not the consequence of cigarette smoking. They are classified histologically as typical carcinoids (TCs) or atypical carcinoids (ACs). ACs confer a worse survival. Histological classification is imperfect, and there is increasing interest in molecular markers. We therefore investigated global transcriptomic and epigenomic profiles of 15 L-CDs resected with curative intent at Royal Brompton Hospital. We identified underlying mutations and structural abnormalities through whole-exome sequencing (WES) and single nucleotide polymorphism (SNP) genotyping. Transcriptomic clustering algorithms identified two distinct L-CD subtypes. These showed similarities either to pancreatic or neuroendocrine tumours at other sites and so were named respectively L-CD-PanC and L-CD-NeU. L-CD-PanC tumours featured upregulation of pancreatic and metabolic pathway genes matched by promoter hypomethylation of genes for beta cells and insulin secretion (p < 1 × 10-6). These tumours were centrally located and showed mutational signatures of activation-induced deaminase/apolipoprotein B editing complex activity, together with genome-wide DNA methylation loss enriched in repetitive elements (p = 2.2 × 10-16). By contrast, the L-CD-NeU group exhibited upregulation of neuronal markers (adjusted p < 0.01) and was characterised by focal spindle cell morphology (p = 0.04), peripheral location (p = 0.01), high mutational load (p = 2.17 × 10-4), recurrent copy number alterations, and enrichment for ACs. Mutations affected chromatin remodelling and SWI/SNF complex pathways. L-CD-NeU tumours carried a mutational signature attributable to aflatoxin and aristolochic acid (p = 0.05), suggesting a possible environmenta
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Journal articleSelvaraj M, Toghani A, Pai H, et al., 2024,
Activation of plant immunity through conversion of a helper NLR homodimer into a resistosome
, PLoS Biology, ISSN: 1544-9173Nucleotide-binding domain and leucine-rich repeat (NLR) proteins can engage in complex interactions to detect pathogens and execute a robust immune response via downstream helper NLRs. However, the biochemical mechanisms of helper NLR activation by upstream sensor NLRs remain poorly understood. Here, we show that the coiled-coil helper NLR NRC2 from Nicotiana benthamiana accumulates in vivo as a homodimer that converts into a higher-order oligomer upon activation by its upstream virus disease resistance protein Rx. The cryo-EM structure of NbNRC2 in its resting state revealed intermolecular interactions that mediate homodimer formation and contribute to immune receptor autoinhibition. These dimerization interfaces have diverged between paralogous NRC proteins to insulate critical network nodes and enable redundant immune pathways, possibly to minimise undesired cross-activation and evade pathogen suppression of immunity. Our results expand the molecular mechanisms of NLR activation pointing to transition from homodimers to higher-order oligomeric resistosomes.
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Journal articlePark Y-K, Peng H, Hapeta P, et al., 2024,
Engineered cross-feeding creates inter- and intra-species synthetic yeast communities with enhanced bioproduction
, Nature Communications, Vol: 15, ISSN: 2041-1723Microorganisms can be engineered to sustainably produce a variety of products including fuels, pharmaceuticals, materials, and food. However, highly engineered strains often result in low production yield, due to undesired effects such as metabolic burden and the toxicity of intermediates. Drawing inspiration from natural ecosystems, the construction of a synthetic community with division of labor can offer advantages for bioproduction. This approach involves dividing specific tasks among community members, thereby enhancing the functionality of each member. In this study, we identify six pairs out of fifteen composed of six auxotrophs of Yarrowia lipolytica that spontaneously form robust syntrophic and synergistic communities. We characterize the stability and growth dynamics of these communities. Furthermore, we validate the existence of syntrophic interactions between two yeast species, Y. lipolytica and Saccharomyces cerevisiae, and find a strain combination, Δtrp2 and Δtrp4, forming a stable syntrophic community between two species. Subsequently, we introduce a 3-hydroxypropionic acid (3-HP) biosynthesis pathway into the syntrophic community by dividing the pathway among different strains. Our results demonstrate improved production of 3-HP in both intra- and interspecies communities compared to monocultures. Our results show the stable formation of synthetic syntrophic communities, and their potential in improving bioproduction processes.
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Journal articleQuintero Santofimio V, Amaral A, Feary J, 2024,
Occupational exposures in low- and middle-income countries: a scoping review
, PLOS Global Public Health, ISSN: 2767-3375Background: Exposure to high levels of harmful agents in the workplace can significantly impact workers’ health, contributing to morbidity and mortality. Levels of these exposures are often measured in high-income countries in research studies and, in some places, to monitor levels in line with health and safety regulations. However, less is known about workplace exposure levels in low- and middle-income countries (LMICs). Our aim was to describe the quantitative exposure measurements of different occupational agents across industries within LMICs. Methods: We conducted a scoping review of peer-reviewed publications available on Web of Science and PubMed from inception to 1 September 2023. Our search focused on quantitative occupational exposure measurements across industries in LMICs.Results: We identified a total of 8,676 publications. After screening, 58 studies from 25 countries were retained for final review. China, Iran, and Tanzania contributed the greatest number of studies. Manufacturing, mining, and agriculture were the most studied sectors, with factory workers and miners being the most common job titles. Exposure measurements included vapour, gases, dust, and fumes (VGDF), solvents, metals, pesticides and particulate matter. Occupational exposure levels for the same industry varied widely across geographical regions.Conclusion: This review provides a comprehensive overview of occupational exposures in LMICs and highlights the absence of data in certain geographical areas and industries. The study contributes valuable insights for directing future research, and the need to optimise the assessment of occupational exposures in LMICs with the aim ultimately of reducing disease.
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Journal articleLiu K, Grover M, Trusch F, et al., 2024,
Paired C-type lectin receptors mediate specific recognition of divergent oomycete pathogens in C. elegans
, Cell Reports, ISSN: 2211-1247 -
Journal articleWoubshete M, Chan LI, Diallinas G, et al., 2024,
The dimer of human SVCT1 is key for transport function.
, Biochim Biophys Acta Biomembr, Vol: 1866Humans and other primates lack the ability to synthesize the essential nutrient, Vitamin C, which is derived exclusively from the diet. Crucial for effective vitamin C uptake are the Na+ dependent Vitamin C transporters, SVCT1 and SVCT2, members of the nucleobase ascorbate transporter (NAT) family. SVCT1 and 2 actively transport the reduced form of Vitamin C, ascorbic acid, into key tissues. The recent structure of the mouse SVCT1 revealed the molecular basis of substrate binding and that, like the other structurally characterised members of the NAT family, it exists as a closely associated dimer. SVCT1 is likely to function via the elevator mechanism with the core domain of each protomer able to bind substrate and move through the membrane carrying the substrate across the membrane. Here we explored the function of a range of variants of the human SVCT1, revealing a range of residues involved in substrate selection and binding, and confirming the importance of the C-terminus in membrane localisation. Furthermore, using a dominant negative mutant we show that the dimer is essential for transport function, as previously seen in the fungal homologue, UapA. In addition, we show that a localisation deficient C-terminal truncation of SVCT1 blocks correct localisation of co-expressed, associated wildtype SVCT1. These results clearly show the importance of the dimer in both correct SVCT1 trafficking and transport activity.
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Journal articleBozkurt O, 2024,
A pathogen effector co-opts a host RabGAP protein to remodel pathogen interface and subvert defense-related secretion
, Science Advances, ISSN: 2375-2548
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