Dissemination of antibiotic-resistant bacteria associated with microplastics collected from Monastir and Mahdia coasts (Tunisia).

The exponential use of plastics and their recalcitrant nature leads to their significant accumulation in the environment. The occurrence of plastic wastes is considered as a serious environmental problem. Additionally, plastic wastes can break down into smaller pieces called microplastics (MPs), leading to further interactions with the environment and living organisms.

Potential of Marine Sponge Metabolites against Prions: Bromotyrosine Derivatives, a Family of Interest.

The screening of 166 extracts from tropical marine organisms (invertebrates, macroalgae) and 3 cyclolipopeptides from microorganisms against yeast prions highlighted the potential of Verongiida sponges to prevent the propagation of prions. We isolated the known compounds purealidin Q (), aplysamine-2 (), pseudoceratinine A (), aerophobin-2 (), aplysamine-1 (), and pseudoceratinine B () for the first time from the Wallisian sponge . We then tested compounds - and sixteen other bromotyrosine and bromophenol derivatives previously isolated from Verongiida sponges against yeast prions, demonstrating the potential of -, , , aplyzanzine C (), purealidin A (), psammaplysenes D () and F (), anomoian F (), and N,N-dimethyldibromotyramine ().

Comparison of kink-band structures and specificities of cell wall polysaccharides in modern and ancient flax fibres.

Flax (Linum usitatissimum L.) is a plant of industrial importance, its fibres being presently used for high-value textile applications, composite reinforcements as well as natural actuators. Human interest in this fibre-rich plant dates back several millennia, including to Ancient Egypt where flax was used extensively in various quotidian items.

Nanocellulose-Based Hybrid Scaffolds for Skin and Bone Tissue Engineering: A 10-Year Overview.

Cellulose, the most abundant polymer on Earth, has been widely utilized in its nanoform due to its excellent properties, finding applications across various scientific fields. As the demand for nanocellulose continues to rise and its ease of use becomes apparent, there has been a significant increase in research publications centered on this biomaterial. Nanocellulose, in its different forms, has shown tremendous promise as a tissue engineered scaffold for regeneration and repair.

A Late Pleistocene hominin footprint site on the North African coast of Morocco.

Footprints represent a relevant vestige providing direct information on the biology, locomotion, and behaviour of the individuals who left them. However, the spatiotemporal distribution of hominin footprints is heterogeneous, particularly in North Africa, where no footprint sites were known before the Holocene. This region is important in the evolution of hominins.

Graph Regression Model for Spatial and Temporal Environmental Data-Case of Carbon Dioxide Emissions in the United States.

We develop a new model for spatio-temporal data. More specifically, a graph penalty function is incorporated in the cost function in order to estimate the unknown parameters of a spatio-temporal mixed-effect model based on a generalized linear model. This model allows for more flexible and general regression relationships than classical linear ones through the use of generalized linear models (GLMs) and also captures the inherent structural dependencies or relationships of the data through this regularization based on the graph Laplacian.

In-situ monitoring of changes in ultrastructure and mechanical properties of flax cell walls during controlled heat treatment.

Plant fibres are increasingly used as reinforcements, especially in thermoplastic composites. Understanding the impact of temperature on the properties of these fibres is an important issue for the manufacturing of high-performance materials with minimal defects. In this work, the structural evolution and mechanical behaviour of flax fibre cell walls were dynamically monitored by temperature-controlled X-ray diffraction and nanoindentation from 25 to 230 °C; detailed biochemical analysis was also conducted on fibre samples after each heating step.

Influence of substrate/inoculum ratio, inoculum source and ammonia inhibition on anaerobic digestion of poultry waste.

Poultry wastes are rich in organic matter, allowing their use as substrates for biogas production by anaerobic digestion (AD). The major difficulty in the anaerobic digestion of this protein-rich waste is ammonia inhibition. Different results of biochemical methane potential (BMP) were obtained after the mesophilic anaerobic digestion of different avian waste in batch mode.

Surfactant Assisted In Situ Synthesis of Nanofibrillated Cellulose/Polymethylsilsesquioxane Aerogel for Tuning Its Thermal Performance.

Nanofibrillated cellulose (NFC) and polymethylsilsesquioxane (PMSQ) based aerogel are prepared by the sol-gel method. The objective of this work is to study the impact of surfactant and base catalyst on the thermal and mechanical performance of the corresponding aerogel. The rheological premonitory assists in predicting the bulk properties of the aerogel.

Conventional Meso-Scale and Time-Efficient Sub-Track-Scale Thermomechanical Model for Directed Energy Deposition.

Thermally-induced distortion and residual stresses in parts fabricated by the additive manufacturing (AM) process can lead to part rejection and failure. Still, the understanding of thermo-mechanical behavior induced due to the process physics in AM process is a complex task that depends upon process and material parameters. In this work, a 3D thermo-elasto-plastic model is proposed to predict the thermo-mechanical behavior (thermal and distortion field) in the laser-directed energy deposition (LDED) process using the finite element method (FEM).

Impact of cell wall non-cellulosic and cellulosic polymers on the mechanical properties of flax fibre bundles.

Fibre bundles are groups of elementary fibres glued together thanks to the middle lamella, and are the main fraction in plant fibre composites. In this study, relationship between the mechanical properties of flax fibre bundles, chemical composition and cellulose structure were investigated. To do so, a sequential biopolymer extraction was implemented.

Evolution of the ultrastructure and polysaccharide composition of flax fibres over time: When history meets science.

Flax fibres have been used by humans for approximately 10,000 years. With time, the geographic area of production and cultivation has changed, as have the applications of flax fibres; from clothing to sails and paintings from antiquity, to automotive, fashion, and design applications in the contemporary era. The degradation process of flax fibres is the same for both ancient and modern objects made from this polysaccharidic material.

Alterins, a new family of marine antibacterial cyclolipopeptides.

Five strains of Pseudoalteromonas, isolated from oyster haemolymph, have exhibited antibacterial activity against several Gram-negative bacteria. Bioactive compounds have been identified in their cell-free supernatant and characterised as alterins, which are cyclolipopeptides comprising a heptapeptidic ring connected to a fatty acid chain. Using ultra-performance liquid chromatography-high-resolution mass spectrometry, this paper describes 37 structural analogues differing from each other by one or more amino acid residue, the length of the fatty acid chain, its hydroxylation and the presence of unsaturation.

sp. nov., a new bacterial species harboured by the flat oyster .

Three bacterial strains, named h-66, h-124 and h-125, were isolated from the haemolymph of different specimens of the flat oyster collected in Concarneau bay (Finistère, France). These strains were characterized by a polyphasic approach, including (i) whole genome analyses with 16S rRNA gene sequence alignment and pangenome analysis, determination of the G+C content, average nucleotide identity (ANI), and DNA-DNA hybridization (DDH), and (ii) fatty acid methyl ester and other phenotypic analyses. Strains h-66, h-124 and h-125 were closely related to both type strains RA15 and PAMC 28425 with less than 93.

Mechanical and Hygroscopic Properties of Molded Pulp Products Using Different Wood-Based Cellulose Fibers.

With an increasing interest for molded pulp product (MPP) in the industry, it is important to fully understand how the manufacturing process is different from papermaking. One specific way to differentiate the processes is to compare their resulting products. As the paper industry uses several wood fibers with various pulping processes, it is interesting to compare some of these fibers, to further progress our understanding of the MPP process.

Lessons on textile history and fibre durability from a 4,000-year-old Egyptian flax yarn.

Flax has a long and fascinating history. This plant was domesticated around 8,000 BCE in the Fertile Crescent area, first for its seeds and then for its fibres. Although its uses existed long before domestication, residues of flax yarn dated 30,000 years ago have been found in the Caucasus area.

Investigations by AFM of Ageing Mechanisms in PLA-Flax Fibre Composites during Garden Composting.

PLA-flax non-woven composites are promising materials, coupling high performance and possible degradation at their end of life. To explore their ageing mechanisms during garden composting, microstructural investigations were carried out through scanning electron microscopy (SEM) and atomic force microscopy (AFM). We observe that flax fibres preferentially degrade 'inwards' from the edge to the core of the composite.

Phidianidine A and Synthetic Analogues as Naturally Inspired Marine Antifoulants.

Stationary and slow-moving marine organisms regularly employ a natural product chemical defense to prevent being colonized by marine micro- and macroorganisms. While these natural antifoulants can be structurally diverse, they often display highly conserved chemistries and physicochemical properties, suggesting a natural marine antifouling pharmacophore. In our current report, we investigate the marine natural product phidianidine A, which displays several chemical properties found in highly potent marine antifoulants.

Hygienization of mixed animal by-product using pulsed electric field in a continuous treatment system: Synergistic effect with ohmic heating on the inactivation of indicator bacteria.

Thermal hygienization of waste animal by-products (ABP) before anaerobic digestion is imposed by EU regulations in order to minimize its sanitary risk during digestate land application. This process is energy and time consuming. The present paper deals with the hygienization of ABP using pulsed electric field (PEF) in a continuous system.

Ultra-fast heat dissipating aerogels derived from polyaniline anchored cellulose nanofibers as sustainable microwave absorbers.

Electromagnetic (EM) pollution is ubiquitous and has soared to a great extent in the past few decades. The use of plant sourced cellulose nanofibers to fabricate sustainable and high performance electromagnetic shielding materials is foreseen as a green solution by the electronics industry to address this unseen pollutant. In this view, we report a facile and environmentally benign strategy to synthesize ultra-light and highly conductive aerogels derived from cellulose nanofibers (CNF) decorated with polyaniline (PANI) via a simple in-situ polymerization and subsequent freeze drying process devoid of any volatile organic solvents.

Crystalline defects in bulk metallic glasses: consequences on fracture toughness determination and ductility.

Dating back to the late 1980s, bulk metallic glasses (BMGs) are relatively new materials that exhibit exceptional mechanical properties (strength, hardness, fracture toughness, stored elastic energy …), compared to those of most crystalline metallic alloys. Their apparent brittleness under uniaxial loading, however, is still a major obstacle to their industrialization. Moreover, BMGs often contain crystalline defects developed, intentionally or not, during their complex and delicate elaboration.

Anaerobic digestion of waste Tunisian date ( L.): effect of biochemical composition of pulp and seeds from six varieties.

Large amounts of secondary date waste (pulp and seeds) are produced and discarded in Tunisia without proper valorisation methods. To study the possibility of valorising different varieties of Tunisian date waste (pulp and seeds) via anaerobic digestion, batch biochemical methane potential (BMP) tests were carried out under mesophilic temperature. The bio-methane production curves were fitted to the model of modified Gompertz in search of the kinetic parameters.

Nailing of Layers: A Promising Way to Reinforce Concrete 3D Printing Structures.

Today, the extrusion-based 3D printing of concrete is a potential breakthrough technology for the construction industry. It is expected that 3D printing will reduce the cost of construction of civil engineering structures (removal of formwork) and lead to a significant reduction in time and improve working environment conditions. Following the use of this additive manufacturing layer-wise process, it is required to change the way concrete structures are designed and reinforced, especially for the parts of the structure under tension loads.

Pseudomonas aeruginosa resistance of monosaccharide-functionalized glass surfaces.

Preventing microorganism colonization on a surface is a great challenge in the conception of medical, food and marine devices. Here, we describe the formation of carbohydrate functionalized glass surfaces with D-glucose, D-galactose and D-mannose and how they efficiently affected the bacterial attachment. The carbohydrate entities were covalently attached to the pre-functionalized surface by click chemistry thanks the copper catalysed alkyl-azide cycloaddition.

Density measurement of liquid 22MnB5 by aerodynamic levitation.

This study is part of the general context of thermophysical characterization of liquid metals with an aerodynamic levitation device and laser heating. The density measurements vs temperature of pure and alloyed metals are determined during cooling of the sample. The temperature and shape of the sample are measured, respectively, with a bichromatic pyrometer and filmed by a high-speed camera.