Search Results (70)

Lettuce is a globally cultivated and consumed leafy crop. Here we developed an efficient tobacco rattle virus (TRV)-based guide RNA (gRNA) delivery system for CRISPR/Cas editing in the commercial lettuce cultivar ‘Noga’. Plants stably expressing Cas9 were inoculated with TRV vectors carrying gRNAs targeting five nutrient-associated genes. The system achieved an average editing efficiency of 48.7%, with up to 78.9% of regenerated plantlets showing independent mutations. This approach eliminates the need for antibiotic selection, simplifying tissue culture processes. The system supports diverse applications, including Cas12a editing and large-fragment deletions using dual gRNA sets. Targeting the fructan 1-exohydrolase 2 (1-FEH2) gene produced knockout lines with significant increases in prebiotic dietary fibre fructan content, up to 5.2-fold, and an average rise in the degree of polymerisation by 2.15 units compared with controls. Combining 1-FEH1 and 1-FEH2 knockouts did not further increase fructan levels, revealing 1-FEH2 as the predominant isozyme in lettuce. RT-qPCR analysis showed reduced expression of the upstream biosynthetic enzyme sucrose:sucrose 1-fructosyl transferase (1-SST), suggesting potential feedback inhibition in fructan metabolism. This TRV-based gene editing approach, utilised here to increase fructan content, could be applied to improve other valuable traits in lettuce, and may inspire similar systems to enhance nutritional content of crops. Full article

Viper bite envenoming often results in prominent skeletal muscle damage. According to our previous studies, the prolonged presence of Crotalus atrox venom toxins induced extensive muscle damage, which mimicked the outcome of chronic muscle damage often seen in human muscular dystrophies. In the case of chronic muscle damage, two critical processes occur: muscle regeneration is impaired, and fibrosis develops. Myostatin/activin signalling is a key regulator of both of these processes. Myostatin and its closely related molecules, in particular activin, inhibit the proliferation and differentiation of myocytes while promoting proliferation of fibroblasts and expression of extracellular matrix proteins. Thus, attenuating myostatin/activin signalling offers an attractive means of promoting muscle development while decreasing fibrosis. Hence, we have used the soluble activin receptor type IIb, which acts as a ligand trap for both myostatin and activin, to dampen signalling and assessed whether this intervention could alter the pathological trajectory of C. atrox venom-induced muscle damage in mice. We report that the soluble activin receptor type IIb treatment increased the size of regenerating fibres while reducing the level of fibrotic tissues in venom-damaged muscle. Full article

The regeneration of endothelial cells (ECs) lining arteries, veins, and large lymphatic vessels plays an important role in vascular pathology. To understand the mechanisms of atherogenesis, it is important to determine what happens during endothelial regeneration. A comparison of these processes in the above-mentioned vessels reveals both similarities and some significant differences. Regeneration is carried out by moving intact ECs from the edges of the viable endothelial layer towards the centre of the EC damage zone. A sharp decrease in contact inhibition leads to the spreading of the edges of the ECs situated on the damage border. This stimulates the second row of ECs to enter the S-phase, then the G2 phase of cell cycle, and finally mitosis. In all three types of vessels studied, mitotically dividing ECs were found using correlation light and electron microscopy. These ECs have a body protruding into the lumen of the vessel, covered with micro-villi and other outgrowths. The level of EC rounding and protruding is highest in the arteries and least pronounced in the lymphatic vessels. The intercellular contacts of mitotically dividing cells become wider. The EC division leads to an increase in the density of ECs. ECs moving over the damaged area and partially outside the damaged area acquire a fusiform shape. In the process of regeneration of arterial endothelium, the damaged ECs are removed. Then health ECs move to a surface devoid of endothelium, and detach spreading out, flattened platelets from the luminal surface of the vessel. In the veins, ECs grow on the surface of platelets and microthrombi. In lymphatic vessels, ECs detach from the basement membrane slower than in the veins and arteries. There, the migrating ECs grow under fibrin fibres. After some time (usually after 30 days), the EC mosaic returns to normal in all three types of vessels. Full article

The lyocell process offers an environmentally friendly strategy to produce regenerated cellulose fibre from biomass. However, it is critical to recover and reuse the N-methyl-morpholine-N-oxide (NMMO) solvent to maximize the environmental benefits and lower the cost. This article reviews NMMO recovery and characterization techniques at the lab and industrial scales, and methods to limit the NMMO degradation during the process. The article also presents the results of a pilot study investigating the recovery of NMMO from lyocell manmade cellulosic fibre (L-MMCF) manufacturing wastewater. The work described includes the development of a calibration curve for the determination of NMMO content in aqueous solutions using Fourier Transform Infrared Spectroscopy (FTIR). Successful NMMO recovery from the wastewater was achieved using a rotary evaporator: the final NMMO concentration was 50, i.e., ready for use in the lyocell process, and no NMMO degradation was observed. The knowledge in this paper will support advances in L-MMCF manufacturing and the reduction in textile environmental footprint. Full article

Achieving high-performance 3D printing composite filaments requires addressing challenges related to fibre wetting and uniform fibre/polymer distribution. This study evaluates the effectiveness of solution (solvent-based) and emulsion (water-based) impregnation techniques to enhance fibre wetting in bleached flax yarns by polylactide (PLA). For the first time, continuous viscose yarn composites were also produced using both impregnation techniques. All the composites were carefully characterised throughout each stage of production. Initially, single yarns were impregnated and consolidated to optimise formulations and processing parameters. Solution impregnation resulted in the highest tensile strength (356 MPa) for PLA/bleached flax filaments, while emulsion impregnation yielded the highest tensile strength for PLA/viscose filaments (255 MPa) due to better fibre wetting and fibre distribution. Impregnated single yarns were then combined, with additional polymer added to produce filaments compatible with standard material extrusion 3D printers. Despite a reduction in the mechanical performance of the 3D-printed composites due to additional polymer impregnation, relatively high tensile and bending strengths were achieved, and the Charpy impact strength (>127 kJ/m²) for the viscose-based composite exceeded the reported values for bio-derived fibre reinforced composites. The robust mechanical performance of these filaments offers new opportunities for the large-scale additive manufacturing of structural components from bio-derived and renewable resources. Full article

Optical probes can be employed in dense and dilute fluidized beds. Their application is useful to determine particle volume fraction, bubble velocity, bubble size, and solid segregation in dense-phase fluidized-bed reactors, as well as particle-cluster velocity, size, and shape, in downer/riser units. The CREC-UWO team has developed a unique and miniaturized CREC Optiprobes System (CREC-GS-OPS) equipped with a GRIN (graded refraction index) lens. The GRIN lens creates a small volume of high light irradiation by focusing a laser a few millimetres away from the front of the probe tip. This design minimizes sensor intrusiveness and, as a result, provides trustworthy measurements of hydrodynamic parameters. Through the application of the CREC-GS-OPS, advances have been achieved, leading to (a) the development of a “Y-back” unit with graphite ferrules that protects the optiprobes from fibre-optic stresses and prevents the loss of sensor calibration and (b) the establishment of statistically-based data analysis. It is envisioned that through the introduction of a few design changes, the CREC Optiprobes will be made suitable for high-temperature applications. This will allow the measurement of catalyst flow recirculation (among other measurements), in industrial-scale fluidized-bed catalytic cracking units involving fluidized riser crackers and catalyst regenerators. Full article

Cataracts are the world’s leading cause of blindness, and diabetes is the second leading risk factor for cataracts after old age. Despite this, no preventative treatment exists for cataracts. The altered metabolism of excess glucose during hyperglycaemia is known to be the underlying cause of diabetic cataractogenesis, resulting in localised disruptions to fibre cell morphology and cell swelling in the outer cortex of the lens. In rat models of diabetic cataracts, this damage has been shown to result from osmotic stress and oxidative stress due to the accumulation of intracellular sorbitol, the depletion of NADPH which is used to regenerate glutathione, and the generation of fructose metabolites via the polyol pathway. However, differences in lens physiology and the metabolism of glucose in the lenses of different species have prevented the translation of successful treatments in animal models into effective treatments in humans. Here, we review the stresses that arise from hyperglycaemic glucose metabolism and link these to the regionally distinct metabolic and physiological adaptations in the lens that are vulnerable to these stressors, highlighting the evidence that chronic oxidative stress together with osmotic stress underlies the aetiology of human diabetic cortical cataracts. With this information, we also highlight fundamental gaps in the knowledge that could help to inform new avenues of research if effective anti-diabetic cataract therapies are to be developed in the future. Full article

In recent years, wind energy has begun to receive a significant amount of attention as clean energy is utilised and demanded in large quantities, resulting in a sharp increase in the use of wind turbines. The demand for wind turbines has gradually risen due to the clean and recyclable nature of wind energy. The current blade life of wind turbines in China is about 20 years, which means that the disposal of obsolete used blades can become a difficult problem in the future. Therefore, this study is of great significance to explore the regeneration performance of the blades after recycling and disposal. In this paper, wind turbine blades were mechanically recycled into recycled macrofibres, which were added to concrete as a reinforcing material to make wind impeller fibre concrete (WIC), and the three proportion ratios of 1%, 1.5%, and 2% were explored to compare the performance. The performance of WIC was also evaluated and its performance was compared to that of glass fibre concrete (GC). In addition, the material physical properties of second-generation recycled aggregate concrete (RAC) based on WIC were explored. The strength and peak strain variations and their causal mechanisms were analysed both macroscopically and microscopically by means of the classical mechanical tests (compression and bending tests), SEM, and XRD. The results show that the compressive strength of WIC was negatively correlated with the fibre content and increased by 6.04–18.12% compared to that of ordinary concrete (OG), with a maximum of 19.25 MPa; the flexural strength was positively correlated with the fibre content, with an increase of 5.37–18.5%. The microstructural analysis confirmed the macroscopic results and the intrinsic model better validated the experimental results. Full article

The textile sector is responsible for a number of environmental impacts, e.g., climate change, and is not pursuing sustainable production and consumption patterns. Due to the increasing quantities of textiles, their share is rising, and a trend reversal from a linear to a circular and sustainable textile chain is needed. This article presents the background, methodological approach and results of a participatory textile development model. In the commercial B2B sector, three textile prototypes were developed together with users and trialled over several months in three application areas. Textile development took into account the requirements of fibre regeneration in the product design and focused on innovative more sustainable chemical recycling solutions. The three sustainably aligned textiles were subjected to spectroscopic and textile–technological tests. The sustainability tool screening life cycle assessments analysed their environmental profile and compared it with reference textiles that are used as the standard. Overall, it is clear that the three textiles can match conventional reference textiles in terms of quality and have considerable environmental benefits compared to the reference textiles. The user survey did identify concerns about a high artificial fibre content, although a general rejection of recycled fibres was not observed. The results show that a sustainable transformation is possible but must start with the fibre composition; recycling, on the other hand, is of minor importance. Full article

With respect to other fields, bone tissue engineering has significantly expanded in recent years, leading not only to relevant advances in biomedical applications but also to innovative perspectives. Polycaprolactone (PCL), produced in the beginning of the 1930s, is a biocompatible and biodegradable polymer. Due to its mechanical and physicochemical features, as well as being easily shapeable, PCL-based constructs can be produced with different shapes and degradation kinetics. Moreover, due to various development processes, PCL can be made as 3D scaffolds or fibres for bone tissue regeneration applications. This outstanding biopolymer is versatile because it can be modified by adding agents with antimicrobial properties, not only antibiotics/antifungals, but also metal ions or natural compounds. In addition, to ameliorate its osteoproliferative features, it can be blended with calcium phosphates. This review is an overview of the current state of our recent investigation into PCL modifications designed to impair microbial adhesive capability and, in parallel, to allow eukaryotic cell viability and integration, in comparison with previous reviews and excellent research papers. Our recent results demonstrated that the developed 3D constructs had a high interconnected porosity, and the addition of biphasic calcium phosphate improved human cell attachment and proliferation. The incorporation of alternative antimicrobials—for instance, silver and essential oils—at tuneable concentrations counteracted microbial growth and biofilm formation, without affecting eukaryotic cells’ viability. Notably, this challenging research area needs the multidisciplinary work of material scientists, biologists, and orthopaedic surgeons to determine the most suitable modifications on biomaterials to design favourable 3D scaffolds based on PCL for the targeted healing of damaged bone tissue. Full article

The potential for using discarded viscose textiles to produce high-quality viscose fibres is limited by the low molecular weight of the cellulose and its continued reduction in the recycling process. Herein, we present a straightforward approach of reprocessing discarded viscose textiles while achieving high-quality recycled viscose fibres. Discarded viscose textile was defibrated and centrifuged, and the resulting fibres were reprocessed under industrially relevant conditions. The produced viscose dope was fluid and resulted in viscose fibres with properties comparable to fibres made from commercial wood cellulose pulp (titer ~2 dtex; dry elongation ~16%, dry tenacity ~15 cN/tex). To explore the potential for a more environmentally friendly production process, the steeping step was performed twice (double-steeping), thereby producing a more homogeneous viscose dope. Through double-steeping, the consumption of carbon disulfide (CS₂) could be reduced by 30.5%. The double-steeping method shows to be a suitable approach to reprocess discarded viscose textiles while reducing the environmental impact of the viscose process associated with the use of CS₂. Our work demonstrates that discarded viscose textile has the potential to be part of a circular textile value chain. Full article

Implantable hydrogels should ideally possess mechanical properties matched to the surrounding tissues to enable adequate mechanical function while regeneration occurs. This can be challenging, especially when degradable systems with a high water content and hydrolysable chemical bonds are required in anatomical sites under constant mechanical stimulation, e.g., a foot ulcer cavity. In these circumstances, the design of hydrogel composites is a promising strategy for providing controlled structural features and macroscopic properties over time. To explore this strategy, the synthesis of a new photocurable elastomeric polymer, poly(glycerol-co-sebacic acid-co-lactic acid-co-polyethylene glycol) acrylate (PGSLPA), is investigated, along with its processing into UV-cured hydrogels, electrospun nonwovens and fibre-reinforced variants, without the need for a high temperature curing step or the use of hazardous solvents. The mechanical properties of bioresorbable PGSLPA hydrogels were studied with and without electrospun nonwoven reinforcement and with varied layered configurations, aiming to determine the effects of the microstructure on the bulk compressive strength and elasticity. The nonwoven reinforced PGSLPA hydrogels exhibited a 60% increase in compressive strength and an 80% increase in elastic moduli compared to the fibre-free PGSLPA samples. The mechanical properties of the fibre-reinforced hydrogels could also be modulated by altering the layering arrangement of the nonwoven and hydrogel phase. The nanofibre-reinforced PGSLPA hydrogels also exhibited good elastic recovery, as evidenced by the hysteresis in compression fatigue stress–strain evaluations showing a return to the original dimensions. Full article

The low efficiency of in vivo transfection of a few fibres revealed a novel tissue network that temporally amplified growth stimulation in the entire regenerating rat soleus muscle. This acupuncture-like effect was demonstrated when the fibres began to grow after complete fibre degradation, synchronous inflammation, myoblast and myotube formation. Neonatal sarcoplasmic/endoplasmic reticulum ATPase (SERCA1b) was first detected in this system. The neonatal, fast and slow SERCA isoforms displayed consequent changes with innervation and differentiation, recapitulating events in muscle development. In vivo transfection of myotubes with plasmids expressing dominant negative Ras or a calcineurin inhibitor peptide (Cain/cabin) proved that expression of the slow myosin heavy chain and the slow muscle type SERCA2a are differentially regulated. In vivo transfection of a few nuclei of myotubes with dnRas or SERCA1b shRNA stimulated fibre size growth in the whole regenerating muscle but only until the full size had been reached. Growth stimulation by Ras and SERCA1b antisense was abolished by co-transfection of Cain or with perimuscular injection of IL4 antibody. This revealed a novel signalling network resembling scale-free networks which, starting from transfected fibre myonuclei as “hubs”, can amplify growth stimulation uniformly in the entire regenerating muscle. Full article

This study investigated the influence of carbon fibre addition on the thermal performances of gypsum compositions doped with 20 wt % of phase-change material (PCM) microspheres. The influences of the length (150 µm/3 mm) and additive amount (0.5/2/4 wt %) of the carbon fibres were investigated. Characterizations were performed throughout the various preparation steps to check that the materials aligned with the construction standards. The consistency of compositions with 3 mm carbon fibres did not seem to be suitable for construction implementation. On the contrary, thanks to an adequate amount of thinning additive, the compositions with 150 µm carbon fibres showed acceptable implementation properties. The materials were tested in a climatic chamber under temperature cycles that were either favourable (15 °C/40 °C) or unfavourable (20 °C/40 °C) for the regeneration process of the PCM. Tests with a plateau at 40 °C/15 °C were also performed to obtain a better understanding of the thermal behaviours. The tests were performed using walls with thicknesses of either 15 mm or 30 mm. The results show that, in all cases, the addition of carbon fibres was not beneficial to the thermal performance of the PCM. These observations were in opposition to those of other studies in the literature. We hypothesized that the performances of these composite materials would be different under convective or conductive fluxes. It was also shown that, in unfavourable conditions (20 °C/40 °C), the large thickness of 30 mm could not be fully regenerated, even in the compositions with carbon fibres. However, the PCM of boxes with 15 mm thick walls was deactivated faster (after ~400 min) than that of those with 30 mm thick walls (after ~700 min). Finally, the laboratory results were compared with the results of a previous large-scale study. It was estimated that, despite a surface-to-volume ratio that was 25 times higher, the energy storage efficiency was only increased by a factor of 2.6 between our laboratory study and the large-scale study. Hence, the PCM storage process seems to be mainly involved in maintaining the temperature of the gypsum walls rather than the temperature of the air. Full article

Hyaline articular cartilage has unique physiological, biological, and biomechanical properties with very limited self-healing ability, which makes the process of cartilage regeneration extremely difficult. Therefore, research is currently focused on finding new and potentially better treatment options. The main objective of this in vivo study was to evaluate a novel biocement CX consisting of tetracalcium phosphate–monetit biocement hardened with a phytic acid–phytase mixture for the regeneration of osteochondral defects in sheep. The results were compared with tetracalcium phosphate–monetit biocement with classic fast-setting cement systems and untreated defects. After 6 months, the animals were sacrificed, and the samples were evaluated using macroscopic and histologic methods as well as X-ray, CT, and MR-imaging techniques. In contrast to the formation of fibrous or fibrocartilaginous tissue on the untreated side, treatment with biocements resulted in the formation of tissue with a dominant hyaline cartilage structure, although fine fibres were present (p < 0.001). There were no signs of pathomorphological changes or inflammation. Continuous formation of subchondral bone and hyaline cartilage layers was present even though residual biocement was observed in the trabecular bone. We consider biocement CX to be highly biocompatible and suitable for the treatment of osteochondral defects. Full article