Search Results (913)

Diabetic retinopathy (DR) is a specific microvascular problem of diabetes, which is mainly caused by hyperglycemia and may lead to rapid vision loss. Dietary polyphenols have been reported to decrease the risk of DR. Apocynum venetum L. leaves are rich in polyphenolic compounds and are popular worldwide for their health benefits as a national tea drink. Building on previous findings of antioxidant activity and aldose reductase inhibition of A. venetum, this study investigated the chemical composition of polyphenol-rich extract of A. venetum leaves (AVL) and its protective mechanism on ARPE-19 cells in hyperglycemia. Ninety-three compounds were identified from AVL by LC-MS/MS, including sixty-eight flavonoids, twenty-one organic acids, and four coumarins. AVL regulated the polyol pathway by decreasing the expression of aldose reductase and the content of sorbitol, enhancing the Na⁺K⁺-ATPase activity, and weakening intracellular oxidative stress effectively; it also could regulate the expression of autophagy-related proteins via the AMPK/mTOR/ULK1 signaling pathway to maintain intracellular homeostasis. AVL could restore the polyol pathway, inhibit oxidative stress, and maintain intracellular autophagy to protect cellular morphology and improve DR. The study reveals the phytochemical composition and protective mechanisms of AVL against DR, which could be developed as a functional food and/or candidate pharmaceutical, aiming for retina protection in diabetic retinopathy. Full article

To reduce the manufacturing cost of polymer electrolyte membrane fuel cells (PEMFCs), tests targeting the decrease of reaction temperature and the amount of reducing agent in the polyol method for the synthesis of Pt/C catalysts were conducted. The reaction temperature in the polyol method was changed from 50 to 160 °C. Through XRD and TGA, it was determined that the reduction of platinum ions by the oxidation of ethylene glycol started at 70 °C. Below a 60 °C reaction temperature, Pt (1 1 1) peaks in XRD were barely visible, indicating that no deposition occurred. TEM revealed that Pt particles were well-dispersed above a 100 °C reaction temperature. For manufacturing platinum catalysts using the polyol method, it was found that 100 °C is the optimal synthesis temperature. Additionally, it was found that similar performance can be achieved by adding water to decrease the amount of ethylene glycol during synthesis. Finally, considering various analyses, it is evident that the dispersion, size, and crystallinity of platinum particles had the most significant impact on performance. Full article

Considering that maize (Zea mays L.) is a staple food for a large segment of the population worldwide, many attempts have been made to improve the nutritional value of its grain and at the same time to achieve sustainable cropping systems. The present study aimed to characterize the composition and nutritional value of maize grain as influenced by cropping system, genetic background (variety), and growing year using untargeted NMR metabolomics. The composition of both water- (sugars and polyols, organic acids, and amino acids) and liposoluble metabolites (free and esterified fatty acids, sterols, and lipids) extracted from the maize grain was determined. Multivariate statistical analyses (PCA and ANOVA) pointed to the growing year and the variety as the most important random and fixed factors, respectively, influencing the metabolite profile. The samples were separated along PC1 and PC3 according to the growing year and the variety, respectively. A higher content of citric acid and diunsaturated fatty acids and a lower content of tyrosine, trigonelline, and monounsaturated fatty acids was observed in the organic with respect to the conventional variety. The effect of the cropping system was overwhelmed by the random effect of the growing year. The results provide novel knowledge on the influence of agronomic practices on maize micronutrient contents. Full article

Waste rubber tires are an area of global concern in relation to reducing the consumption of petrochemical products and environmental pollution. Herein, eco-friendly high-performance thermoplastic polyurethane (PU) elastomers were successfully in-situ synthesized through the incorporation of ground tire rubber (GTR). The excellent wet-skid resistance of PU/GTR elastomer was achieved by using mixed polycaprolactone polyols with Mn = 1000 g/mol (PCL-1K) and PCL-2K as soft segments. More importantly, an efficient solution to balance the contradiction between dynamic heat build-up and wet-skid resistance in PU/GTR elastomers was that low heat build-up was realized through the limited friction between PU molecular chains, which was achieved with the help of the network structure formed from GTR particles uniformly distributed in the PU matrix. Impressively, the tanδ at 60 °C and the DIN abrasion volume (Δrel) of the optimal PU/GTR elastomer with 59.5% of PCL-1K and 5.0% of GTR were 0.03 and 38.5 mm³, respectively, which are significantly lower than the 0.12 and 158.32 mm³ for pure PU elastomer, indicating that the PU/GTR elastomer possesses extremely low rolling resistance and excellent wear resistance. Meanwhile, the tanδ at 0 °C of the above-mentioned PU/GTR elastomer was 0.92, which is higher than the 0.80 of pure PU elastomer, evidencing the high wet-skid resistance. To some extent, the as-prepared PU/GTR elastomer has effectively solved the “magic triangle” problem in the tire industry. Moreover, this novel research will be expected to make contributions in the upcycling of waste tires. Full article

With the increasing drilling depth of mines, the cross-complexity of fissures in the rock body, and the frequent occurrence of sudden water surges, polymer slurry, with its advantages of good permeability and strong water plugging, is increasingly used in mine grouting projects. Additional research is needed in order to further improve the grouting performance of polymer slurry, ensure the safety of mining operations, and reduce the grouting cost. In this paper, a polymer composite grouting material was prepared with diphenyl methyl diisocyanate, polyether polyol, and fly ash, as the main raw materials, with coupling agent and catalyst as auxiliary reagents. The performance of the composite grouting material in terms of mechanical properties, thermal stability, hydrophobicity, and bonding was explored. This study’s findings indicated that incorporating fly ash led to notable enhancements in the thermal stability and water resistance of the polymer slurry. Furthermore, the introduction of fly ash notably raised the starting degradation temperature of the polymer, boosted the water contact angle of the composite material, and reduced the density and reaction temperature of the composite material. In addition, the catalyst and coupling agent as auxiliary reagents affected the polymers in terms of mechanical properties; in this paper, dibutyltin dilaurate was used as the catalyst, and organosilanes were used as the coupling agent. The catalyst successfully sped up the polymer’s gel time, however, an excessive quantity of catalyst compromised the polymer’s mechanical characteristics. The addition of organosilanes has a positive effect on the dynamic mechanical properties of the composites, fracture toughness, compression, bending, and bond strength. The research can offer a theoretical direction for creating polymer mixtures in mine grouting projects. Full article

Cryogenics is the science and technology of very low temperatures, typically below 120 K. The most common applications are liquified natural gas carriers, ground-based tanks, and propellant tanks for space launchers. A crucial aspect of cryogenic technology is effective insulation to minimise boil-off from storage tanks and prevent frost build-up. Rigid closed-cell foams are prominent in various applications, including cryogenic insulation, due to their balance between thermal and mechanical properties. Polyurethane (PU) foam is widely used for internal insulation in cryogenic tanks, providing durability under thermal shocks and operational loads. External insulation, used in liquified natural gas carriers and ground-based tanks, generally demands less compressive strength and can utilise lower-density foams. The evolution of cryogenic insulation materials has seen the incorporation of environmentally friendly blowing agents and bio-based polyols to enhance sustainability. Fourth-generation physical blowing agents, such as HFO-1233zd(E) and HFO-1336mzz(Z), offer low global warming potential and improved thermal conductivity. Additionally, bio-based polyols from renewable resources like different natural oils and recycled polyethylene terephthalate (PET) are being integrated into rigid PU foams, showing promising properties for cryogenic applications. Research continues to optimise these materials for better mechanical performance and environmental impact. 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

The accumulation of salt in arable lands is a source of significant abiotic stress, contributing to a 10% decline in the world’s total arable lands and threatening food productivity and the sustainability of agriculture. About 76 million hectares of productive land are estimated to have been affected by human-induced salinization such as extreme salt deposits in soil, which are mainly caused by the actions of humans. For instance, continued irrigation and the frequent use of chemical fertilizers need to be understood. To ensure food availability, it is essential to improve upon traditional farming methods using current technologies to facilitate the reclamation of saline-affected arable lands to achieve high and sustainable food production. This review details current innovative strategies such as the modification of metabolic pathways, manipulation of antioxidant pathways, genetic engineering, RNA interference technology, engineered nanoparticles, arbuscular mycorrhizal fungi (AMF), organic amendments, and trace elements for improving saline marginal lands. These strategies were identified to have contributed to the improvement of plants salinity tolerance in diverse ways. For instance, the accumulation of plant metabolites such as amino acids, sugars, polyols, organic acids, saponins, anthocyanins, polyphenols, and tannins detoxify plants and play crucial roles in mitigating the detrimental effects of oxidative damage posed by salinity stress. Multiple plant miRNAs encoding the up- and down-regulation of single- and multi-ion transporters have been engineered in plant species to enhance salt tolerance. Nanomaterials and plant root system colonized by arbuscular mycorrhizal increase water uptake, photosynthetic efficiency, and biomass allocation in plants exposed to saline stress by excluding 65 percent of the Na⁺ uptake and enhancing K⁺ uptake by 84.21 percent. Organic amendments and trace elements reduced salinity concentrations by 22 percent and improved growth by up to 84 percent in maize subjected to salinity stress. This study also discusses how researchers can use these strategies to improve plants growth, development, and survival in saline soil conditions to enhance the productivity and sustainability of agriculture. The strategies discussed in this study have also proven to be promising approaches for developing salinity stress tolerance strategies for plants to increase agricultural productivity and sustainability. Full article

Polyurethanes (PU) have drawn great attention due to their excellent mechanical properties and self-healing and recyclable abilities. Lignin is a natural and renewable raw material in nature, composed of a large number of hydroxyl groups, and has a great potential to replace petroleum polyols in PU synthesis. This review summarizes the recent advances in modification methods such as the liquefaction, alkylation, and demethylation of lignin, and a systematic analysis of how to improve the reactivity and monomer substitution of lignin during polyurethane synthesis for the green manufacturing of high-performance polyurethanes was conducted. Polyurethane can be used in the form of films, foams, and elastomers instead of conventional materials as a dielectric or substrate material to improve the reliability and durability of flexible sensors; this review summarizes the green synthesis of polyurethanes and their applications in flexible electronics, which are expected to provide inspiration for the wearable electronics sector. Full article

Deep eutectic solvents (DES) represent a promising class of green solvents, offering particular utility in the extraction and development of new formulations of natural compounds such as ferulic acid (FA). The experimental phase of the study undertook a systematic investigation of the solubility of FA in DES, comprising choline chloride or betaine as hydrogen bond acceptors and six different polyols as hydrogen bond donors. The results demonstrated that solvents based on choline chloride were more effective than those based on betaine. The optimal ratio of hydrogen bond acceptors to donors was found to be 1:2 molar. The addition of water to the DES resulted in a notable enhancement in the solubility of FA. Among the polyols tested, triethylene glycol was the most effective. Hence, DES composed of choline chloride and triethylene glycol (TEG) (1:2) with added water in a 0.3 molar ration is suggested as an efficient alternative to traditional organic solvents like DMSO. In the second part of this report, the affinities of FA in saturated solutions were computed for solute-solute and all solute-solvent pairs. It was found that self-association of FA leads to a cyclic structure of the C28 type, common among carboxylic acids, which is the strongest type of FA affinity. On the other hand, among all hetero-molecular bi-complexes, the most stable is the FA-TEG pair, which is an interesting congruency with the high solubility of FA in TEG containing liquids. Finally, this work combined COSMO-RS modeling with machine learning for the development of a model predicting ferulic acid solubility in a wide range of solvents, including not only DES but also classical neat and binary mixtures. A machine learning protocol developed a highly accurate model for predicting FA solubility, significantly outperforming the COSMO-RS approach. Based on the obtained results, it is recommended to use the support vector regressor (SVR) for screening new dissolution media as it is not only accurate but also has sound generalization to new systems. Full article

Polyurethane foams are materials characterized by low density and thermal conductivity and can therefore be used as thermal insulation materials. They are synthesized from toxic and environmentally unfriendly petrochemicals called isocyanates and polyols, which react with each other to form a urethane group via the displacement of the movable hydrogen atom of the −OH group of the alcohol to the nitrogen atom of the isocyanate group. The following work describes the synthesis of polyurethane foams, focusing on using environmentally friendly materials, such as polyols derived from plant sources or modifiers, to strengthen the foam interface derived from plant precipitation containing cellulose derived from paper waste. The polyurethane foam industry is looking for new sources of materials to replace the currently used petrochemical products. The solutions described are proving to be an innovative and promising area capable of changing the face of current PU foam synthesis. Full article

One of the intensively developed tools for cancer therapy is drug-releasing matrices. Polyamidoamine dendrimers (PAMAM) are commonly used as nanoparticles to increase the solubility, stability and retention of drugs in the human body. Most often, drugs are encapsulated in PAMAM cavities or covalently attached to their surface. However, there are no data on the use of PAMAM dendrimers as a component of porous matrices based on polyurethane foams for the controlled release of drugs and biologically active substances. Therefore, in this work, porous materials based on polyurethane foam with incorporated third-generation poly(amidoamine) dendrimers (PAMAM G3) were synthesized and characterized. Density, water uptake and morphology of foams were examined with SEM and XPS. The PAMAM was liquefied with polyether polyol (G441) and reacted with polymeric 4,4′-diphenylmethane diisocyanate (pMDI) in the presence of silicone, water and a catalyst to obtain foam (PF1). In selected compositions, the castor oil was added (PF2). Analogs without PAMAM G3 were also synthesized (F1 and F2, respectively). An SEM analysis of foams showed that they are composed of thin ribs/walls forming an interconnected network containing hollow bubbles/pores and showing some irregularities in the structure. Foam from a G3:G441:CO (PF2) composition is characterized by a more regular structure than the foam from the composition without castor oil. The encapsulation efficiency of drugs determined by the XPS method shows that it varies depending on the matrix and the drug and ranges from several to a dozen mass percent. In vitro biological studies with direct contact and extract assays indicated that the F2 matrix was highly biocompatible. Significant toxicity of dendrimeric matrices PF1 and PF2 containing 50% of PAMAM G3 was higher against human squamous carcinoma cells than human immortalized keratinocytes. The ability of the matrices to immobilize drugs was demonstrated in the example of perspective (Nimesulide, 8-Methoxypsolarene) or approved anticancer drugs (Doxorubicin—DOX, 5-Aminolevulinic acid). Release into the culture medium and penetration of DOX into the tested SCC-15 and HaCaT cells were also proved. The results show that further modification of the obtained matrices may lead to their use as drug delivery systems, e.g., for anticancer therapy. Full article

As the most abundant bioenergy raw material in nature, cellulose can be converted into sugar by hydrolysis, which can be further degraded to produce downstream chemicals, such as polyols. Hydrolysis technology is one of the key steps in the development and utilization of cellulosic biomass resources. In this study, the ionic liquid (IL)-catalyzed hydrolysis of sugarcane cellulose into reducing sugar was studied. Firstly, the hydrolysis of sugarcane cellulose in different ionic liquids (including benzothiazolomethane sulfonate, [HBth][CH₃SO₃] and 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate, [C₃SO₃Hmim]HSO₄) in heterogeneous and homogeneous systems to produce reducing sugar was studied. In a homogeneous system, the catalytic effect of an ionic liquid on sugarcane cellulose was explored. The pretreatment, IL dosage (0.1~1.0 g), reaction temperature (100~180 °C), addition of water (0~500 μL), and time (1~6 h) were all discovered as key conditions for hydrolysis. The acidity of an acidic ionic liquid is a key factor affecting the hydrolysis of sugarcane cellulose; meanwhile, effective pretreatment and water are also important. As a comparison, the catalytic effect of [C₃SO₃Hmim]HSO₄ in heterogeneous systems (the maximum yield of 5.98% for total reducing sugars, TRS) was not as good as that of [HBth][CH₃SO₃] in homogeneous systems (33.97%). A higher temperature does not necessarily lead to an increased TRS yield, but it will make the maximum TRS appear earlier. At last, 732 cationic ion exchange resin was used to investigate the separation of reducing sugar and ionic liquid, and the recovery of ionic liquid was investigated by an adsorption–desorption experiment. The ionic liquid can be well separated from TRS in the [HBth][CH₃SO₃] and reused at least five times. Full article

Autism rates have been reported to be increasing rapidly in industrialized societies. The pathology most often combines neurological symptoms associated with language and social impairments with gastrointestinal symptoms. This study aimed to measure differences in oral metatranscriptome and mitochondrial health between ASD children and neurotypical USA and Colombia (“Blue Zone”) children. In addition, this study aimed to determine whether using prebiotics and probiotics would change the oral microbiome and mitochondrial health of ASD children. Buccal swabs and saliva samples were obtained from 30 autistic individuals (USA) at three intervals: prior to intervention, post-prebiotic, and post-probiotic. In addition, a subject component who were neurotypical, which included individuals from the USA (30) and Colombia (30), had buccal swabbing and salivary sampling performed for metatranscriptomic and mitochondrial comparison. Significant differences were observed in the temporal data, demonstrating shifts that interventions with probiotics and polyols may have precipitated. Particular bacterial strains were significantly more prevalent in the autism group, including a strain that reduced neurotransmitter levels via enzymatic degradation. This supports the hypothesis that the microbiome may influence the occurrence and degree of autism. Verbal skills increased in six of the 30 ASD subjects following xylitol and three more after probiotic supplementation, according to both parental reports and the subjects’ healthcare providers. Full article

Until recently, recycling thermoset polyurethanes (PUs) was limited to degrading methods. The development of covalent adaptable networks (CANs), to which PUs can be assigned, has opened novel possibilities for actual recycling. Most efforts in this area have been directed toward inventing new materials that can benefit from CAN theory; presently, little or nothing has been applied to industrially producible materials. In this study, both an industrially available polyol (Sovermol780^®) and isocyanate (Tolonate X FLO 100^®) with percentages of bioderived components were employed, resulting in a potentially scalable and industrially producible material. The resultant network could be reworked up to three times, maintaining the crosslinked structure without significantly changing the thermal properties. Improvements in mechanical parameters were observed when comparing the pristine material to the material exposed to three rework processes, with gains of roughly 50% in elongation at break and 20% in tensile strength despite a 25% decrease in Young’s modulus and crosslink density. Thus, it was demonstrated that theory may be profitably applied even to materials that are not designed including additional bonds but instead rely just on the dynamic urethane bond that is naturally present in the network. Full article