Search Results (87)

Imine-linked covalent organic frameworks (COFs) have attracted considerable interest in recent years because they can form strong and reversible covalent bonds, enabling the development of highly ordered crystalline structures. This reversibility is crucial in correcting structural defects during the crystallization process, which requires sufficient time to proceed. This review critically examines the advancements in synthetic strategies for these valuable materials, focusing on catalytic versus conventional approaches. Traditional methods for synthesizing imine-linked COFs often involve harsh reaction conditions and prolonged reaction times, which can limit the scalability and environmental sustainability of these frameworks. In contrast, catalytic approaches offer more efficient pathways, enabling shorter reaction times, milder reaction conditions, and higher yields. This article elucidates the key differences between these methodologies and examines the impact of reduced reaction times and milder conditions on the crystallinity and porosity of COFs. By comparing the catalytic and conventional synthesis routes, this review aims to provide a comprehensive understanding of the advantages and limitations of each approach, offering insights into the optimal strategies for the development of high-performance COFs. Full article

High permeance combined with high salt/dye separation efficiency is a prerequisite for achieving zero-liquid-discharge treatment of saline textile wastewater by membrane technology. Thin-film nanocomposite (TFN) membranes incorporating porous nanoparticles offer a promising route to overcome the permeability–selectivity trade-off of conventional polymer membranes. In this study, a vacuum-assisted method was used to co-blend ZIF-67 and SiO₂ nanoparticles, while branched polyethyleneimine (PEI) served as a cross-linking bridge, resulting in a high-performance TFN membrane for salt/dye separation. Acting as a molecular connector, PEI coordinated with ZIF-67 through metal–amine complexation and simultaneously formed hydrogen bonds with surface hydroxyl groups on SiO₂, thereby linking ZIF-67 and SiO₂. The resulting membrane exhibited good hydrophilicity and excellent dye separation performance (water flux = 359.8 L m⁻² h⁻¹ bar⁻¹; Congo Red rejection = 99.2%) as well as outstanding selectivity in dye/salt mixtures (Congo Red/MgCl₂ selectivity of 1094). The optimal ZIF@SiO₂-PEI membrane maintained stable dye rejection over a wide range of trans-membrane pressures, initial concentrations, and pH values. These results reveal the huge potential of applying the ZIF@SiO₂-PEI TFN membranes for resource recovery in sustainable textile wastewater systems. Full article

Polyurethane (PU) is widely employed in the biomedical field. As application scenarios become increasingly complex, it is essential to modify PU to meet diverse requirements. Additionally, the degradation of PU is closely linked to the sustainability of its function, with degradation products having a direct impact on adjacent tissues. In this study, a novel PU containing double bonds in its main chain was developed. We investigated the influence of various ratios of soft segment composition on the degradation performance of PU, maintaining a fixed ratio of soft to hard segments and utilizing specific synthesis methods. The structure and molecular weight of the PU were analyzed using FTIR, NMR, and GPC techniques. The results of physical and chemical performance tests indicated that an increase in polycaprolactone diol (PCL diol) content within the soft segment enhanced the mechanical properties, hydrophobicity, and degradation performance of the PU. A further assessment of the degradation toxicity of PU was carried out using zebrafish as a model organism. The findings indicated that the degradation solution of PU exhibited slight toxicity to zebrafish embryonic development over prolonged degradation periods. However, it also significantly enhanced the hatching of zebrafish embryos. In summary, the novel PU developed in this study demonstrates favorable biocompatibility, and the approach of introducing reaction sites or modifying the composition of its soft segments within the molecular structure offers a promising and effective strategy to address specific application requirements. Full article

The removal of pharmaceutical contaminants like the anticonvulsant carbamazepine (CBZ) from water sources is a growing environmental challenge. This study explores the development of molecularly imprinted polymers (MIPs) tailored for CBZ adsorption using a bulk polymerization approach. Initially, this study focused on selecting the optimal cross-linker, comparing a trifunctional (trimethylolpropane triacrylate, TRIM) and a bifunctional cross-linker (ethylene glycol dimethacrylate, EGDMA) in combination with two common monomers (2-vinylpyridine and methacrylic acid). TRIM-based MIPs demonstrated superior adsorption efficiency and stability due to their higher cross-linking density. To improve sustainability, six bio-based monomers were investigated; of these, eugenol (EUG) and coumaric acid (COU) showed the best CBZ affinity due to π-π interactions and hydrogen bonding. Adsorption tests conducted in pharmaceutical-spiked real wastewater demonstrated that MIPs exhibit a high selectivity for CBZ over other pharmaceuticals like the anti-inflammatory drugs diclofenac (DCF) and ibuprofen (IBU), even at high concentrations. Reaction conditions were further optimized by adjusting the reaction time and the ratio between reagents to enhance selectivity and adsorption performance. These results highlight the potential of bio-based MIPs as efficient and selective materials for the removal of pharmaceutical pollutants from wastewater. Full article

This study investigates the influence of exposure to climate change on the readability of narrative disclosures in annual reports. Analyzing a sample of 38,229 firm-year observations from 2002 to 2022, the study provides evidence supporting the information obfuscation hypothesis. Specifically, it finds that exposure to climate change is linked to less readable annual reports. This effect is both statistically and economically significant; a one standard deviation increase in climate change exposure leads to an 8.5% reduction in readability. Moreover, this effect is particularly evident among firms operating in environmentally sensitive industries, as well as those characterized by weak corporate culture. Additional tests indicate that the different aspects of climate change exposure (opportunity, physical, and regulatory) are individually associated with a decrease in readability of annual reports, with the physical dimension exerting the most significant impact. The findings underscore the necessity of implementing measures to mitigate climate change exposure and enhance sustainable business environments, such as transitioning to renewable energy sources (such as solar, wind, and hydro), minimizing dependence on fossil fuels, minimizing emissions from industries and transportation, sourcing low-carbon materials, adopting circular economy models, directing capital toward climate-friendly projects, and managing climate risks through catastrophe bonds and climate insurance. The significance of these actions is underscored by the impact of climate change on firms’ information environments, as documented in the current study. Full article

This study developed a novel water-soluble Cellulose Acetoacetate (CAA)-chitosan (CS) composite hydrogel drug delivery system. In this system, CAA and CS molecules are cross-linked via dynamic enamine bonds, forming a three-dimensional network structure suitable for drug encapsulation and controlled release. The primary objective was to address the challenges associated with the short half-life and significant fluctuations in therapeutic concentration of cytokine drugs, such as interleukin-2 (IL-2). A hydrogel system with a three-dimensional spatial network structure was successfully constructed via dynamic enamine bonds cross-linking between the acetoacetate groups in CAA molecules and the amino groups in CS. This system exhibits the following characteristics: (1) Dynamic covalent bonds impart adjustable mechanical properties to the hydrogel, enabling precise control over gelation time and mechanical performance; (2) A hierarchical pore structure (average pore size of 100–200 μm) provides a three-dimensional confined space for efficient drug encapsulation, achieving an IL-2 encapsulation efficiency of 83.3 ± 3.1%; (3) In vitro release studies demonstrated that the cumulative release of IL-2 within 72 h ranged from 18.4% to 34.7%, indicating sustained-release behavior. Cell viability assays confirmed that the hydrogel maintained the survival rate of L929 cells above 85% (as determined by the CCK-8 method), and live/dead staining revealed no apparent cytotoxicity. Overall, this three-dimensional network hydrogel based on dynamic covalent bonds represents a promising strategy for low-dose, long-lasting cytokine delivery. Full article

Somali refugee youth face intersecting stressors related to displacement, economic hardship, and systemic exclusion, yet their coping strategies remain understudied. This study examines the psychosocial distress, coping mechanisms, and help-seeking behaviors of Somali refugee youth in Nairobi’s urban displacement context using a mixed-methods approach. Quantitative analyses assess the prevalence of stressors, coping strategies, and perceived support, while qualitative responses provide insight into lived experiences. Findings reveal that 72% of participants reported distress linked to economic insecurity (15.9%), family separation (16.9%), or refugee-related adversities (13.2%). Religious coping (59.5%) and self-care practices (60.5%) were the most frequently used strategies, while 15.8% relied on avoidance-based methods. Help-seeking patterns showed that 76.7% of participants were willing to seek help in general, but only 40.7% did so for emotional issues, with mothers and same-sex friends being primary sources. Regression analysis (R² = 0.507, p < 0.001) showed that scope of community (β = 0.417, p = 0.001), trust in bonding social capital (β = 0.343, p = 0.012), and perceived community violence (β = 0.346, p = 0.003) were positively associated with perceived support. In contrast, help-seeking intention (β = −0.206, p = 0.049) was negatively associated with perceived support. Other variables—including religious coping, emotional coping, age, gender, and bridging trust—were not significant predictors. These findings underscore the need for community-driven mental health interventions that strengthen existing social structures while integrating culturally adapted service models. Leveraging social capital is essential for fostering sustainable, accessible, and community-based mental health support for displaced Somali youth. Full article

Addressing climate change requires a deeper understanding of all greenhouse gases, yet nitrous oxide (N₂O)—despite its significant global warming potential—remains underrepresented in sustainability analysis and policy discourse. The paper examines N₂O emissions from an environmental, social, and governance (ESG) standpoint with a combination of econometric and machine learning specifications to uncover global trends and policy implications. Results show the overwhelming effect of ESG factors on emissions, with intricate interdependencies between economic growth, resource productivity, and environmental policy. Econometric specifications identify forest degradation, energy intensity, and income inequality as the most significant determinants of N₂O emissions, which are in need of policy attention. Machine learning enhances predictive power insofar as emission drivers and country-specific trends are identifiable. Through the integration of panel data techniques and state-of-the-art clustering algorithms, this paper generates a highly differentiated picture of emission trends, separating country groups by ESG performance. The findings of this study are that while developed nations have better energy efficiency and environmental governance, they remain significant contributors to N₂O emissions due to intensive industry and agriculture. Meanwhile, developing economies with energy intensity have structural impediments to emission mitigation. The paper also identifies the contribution of regulatory quality in emission abatement in that the quality of governance is found to be linked with better environmental performance. ESG-based finance instruments, such as green bonds and impact investing, also promote sustainable economic transition. The findings have the further implications of additional arguments for mainstreaming sustainability in economic planning, developing ESG frameworks to underpin climate targets. Full article

This research work focuses on the chemical recycling of a Carbon Fiber-Reinforced Composite (CFRC) manufactured through a vacuum-assisted resin infusion (VARI) process, characterized by a high Young’s modulus of approximately 7640 MPa. The recycling reaction was performed using a mixture of eco-sustainable solvents, composed of acetic acid and hydrogen peroxide, and was conducted at three different temperatures (70, 80, and 90 °C). The reaction yield values, evaluated with an innovative approach that involved the use of thermogravimetric analysis (TGA), confirmed the importance to recycle at a temperature corresponding to the glass transition temperature (Tg = 90.3 °C) of the resin. Spectroscopic investigations highlighted that the chemical bond cleavage occurred through the selective breaking of the C-N bonds of the cross-linked matrix structure, allowing the recovery of both the reinforcing phase of the epoxy matrix and the initial oligomers/monomers of the epoxy matrix. The morphological and electrical investigations carried out on the recovered fibers further confirmed the efficiency of the recycling process conducted at the highest explored temperature, allowing the recovery of cleaner fibers with an electrical conductivity value (8.04 × 10² S/m) closer to that of virgin fibers (2.20 × 10³ S/m). The proposed strategy is a true challenge in terms of saving energy, solving waste disposal problems, preserving the earth, and preventing the depletion of planet resources. Full article

Superoxide dismutase 1 (SOD1) is a crucial enzyme that protects cells from oxidative damage by converting superoxide radicals into H₂O₂ and O₂. This detoxification process, essential for cellular homeostasis, relies on a precisely orchestrated catalytic mechanism involving the copper cation, while the zinc cation contributes to the structural integrity of the enzyme. This study presents the 2.3 Å crystal structure of human SOD1 (PDB ID: 9IYK), revealing an assembly of six homodimers and twelve distinct active sites. The water molecules form a complex hydrogen-bonding network that drives proton transfer and sustains active site dynamics. Our structure also uncovers subtle conformational changes that highlight the intrinsic flexibility of SOD1, which is essential for its function. Additionally, we observe how these dynamic structural features may be linked to pathological mutations associated with amyotrophic lateral sclerosis (ALS). By advancing our understanding of hSOD1’s mechanistic intricacies and the influence of water coordination, this study offers valuable insights for developing therapeutic strategies targeting ALS. Our structure’s unique conformations and active site interactions illuminate new facets of hSOD1 function, underscoring the critical role of structural dynamics in enzyme catalysis. Moreover, we conducted a molecular docking analysis using SOD1 for potential radical scavengers and Abelson non-receptor tyrosine kinase (c-Abl, Abl1) inhibitors targeting misfolded SOD1 aggregation along with oxidative stress and apoptosis, respectively. The results showed that CHEMBL1075867, a free radical scavenger derivative, showed the most promising docking results and interactions at the binding site of hSOD1, highlighting its promising role for further studies against SOD1-mediated ALS. Full article

Soil structural stability is fundamentally linked to soil functionality and sustainable productivity. Rheological properties describe the deformation and flow behavior of soil under external stress, playing a crucial role in understanding soil structure stability. Despite their importance, the studies about rheological properties of black soils in Northeast China remain limited. This study aims to assess the rheological properties of two kinds of black soil with different degrees of degradation in Northeast China. The rheological parameters of these soils under various water contents and shearing were quantified by conducting Amplitude Sweep Tests (ASTs) and Rotational Sweep Tests (RSTs). Both AST and RST results showed that as soil water content and shear rate increased, shear strength, viscosity, and hysteresis area all decreased in Keshan and Binxian black soils. The increase in soil water content reduces the friction between soil particles, leading to a decrease in soil structure stability. Additionally, the viscosity and hysteresis area of the two soils decreased with the increase in water content, making it more flowable and exhibiting shear-thinning behavior. Keshan black soil exhibited stronger recovery and shear strength compared to Binxian black soil; this is mainly due to the higher organic matter content in Keshan soil, which could increase structural stability by bonding the soil particles at the micro-level. These findings enhance our understanding about the structure stability of the black soils based on the rheological parameters via rheometer. Full article

One of the most significant recent developments in the debt financing sector pertains to new products and standards applicable to sustainability-related issues. Therefore, research on this has increased substantially. One of the most recent such developments is that of sustainability-linked bonds (SLBs). In 2023, global sustainable bond issuance experienced an increase of three percent, nearly reaching USD 1 trillion with significant shifts observed in categories, including green-, social-, sustainability-, and sustainability-linked bonds (GSSSBs). This paper presents one of the most extensive literature reviews on SLBs research, examining trends, research evolution, thematic landscape, and underexplored topics by employing bibliometric and content analysis approaches. It identifies future research avenues and trends, including supporting issuers in transitioning towards net-zero emissions or broader objectives, such as implementing sustainability targets to fight climate change, the premium associated with bond pricing, the potential for greenwashing, and the blockchain technology for issuance and target’s monitoring transparency. In addition, this paper discusses the new trend of thematic bonds, such as those addressing gender characteristics, as innovative strategies to promote societal equity. The systematic literature review also explores the significance of SLBs as public instruments, like sovereign bonds or private instruments, while identifying research areas, including linking SLBs with the evolution of management theory. Full article

Sustainable leisure, shared among grandparents and grandchildren, provides multiple benefits, as it enhances contexts and bonds that foster personal, familiar, social and emotional development. In addition to this, it directly contributes to the achievement of the sustainable development goals, established in Agenda 2030. The objective was to examine, from the grandparents’ perspective, and taking into account their educational level, the links that exist among co-learning processes and the practice of sustainable intergenerational leisure and its evolution throughout the pandemic era. This project sought to combine quantitative (N = 350) and qualitative (N = 18) methodologies, using an ad hoc questionnaire and a discussion group, in different moments, before and after the pandemic. The SPSS 23.0 statistical program was used for quantitative analysis and the NVivo Release 1.6 software for the qualitative study. The results show that intergenerational co-learning is a motive and a relevant stimulus that encourages both generations to share these experiences in natural spaces, which brings them together and facilitates lifelong learning. It has been proven that, before the lockdown, sustainable leisure practices showed significant differences depending on the level of education of the older generation. This had an impact on participation in activities associated with different types of leisure, with a tendency to increase the practice as the level of education rises. Nevertheless, after the pandemic, a greater reduction has been observed in the practice of shared leisure activities among those with a higher educational level. Full article

This paper introduces a new concept of a smart and sustainable tire based on a removable tread band: ECOTIRE. Current tires, though crucial for road information and vehicle control, such as braking, traction, and turning, remain disconnected from Advanced Driver Assistance Systems (ADAS). Additionally, their production, use, and recycling pose significant environmental challenges, requiring sustainable materials and lifecycle improvements. The ECOTIRE concept makes it possible to separate the part of the tire subject to wear and apply new materials with reduced environmental impact. At the same time, the service life of the casing is extended, facilitating the introduction of sensors that improve vehicle safety. This study explores the purely mechanical connection between the casing and tread, demonstrating the feasibility of this innovative tire structure while eliminating the need for rubber matrix-based materials for a proper bond between the two components. Experimental tests using a rubber sample to simulate the tire–road contact patch validate the effectiveness of the mechanical link under varying normal loads. Grip test results, measuring longitudinal and lateral forces, show promising performance. This advancement in tire technology marks a first step toward sustainability, tire performance, and smart integration, ultimately reducing environmental impact. Full article

This study investigated the effects of calcium oxide (CaO) derived from eggshells on the gelation properties of surimi prepared from giant snakehead (Channa micropeltes). Surimi gels were enriched with CaO at concentrations of 0, 2, 4, 6, 8, and 10 µmol/100 g, and their physicochemical, rheological, and structural characteristics were evaluated. The optimal CaO concentration (6 µmol/100 g) significantly enhanced gel strength by 48.2%, breaking force by 26%, and deformation by 18% compared to the control (p < 0.05). Expressible moisture content decreased from 16.88% to 7.12%, while total sulfhydryl groups were reduced to 5.17 µmol/100 g. Rheological analysis revealed increased storage modulus (G′) and loss modulus (G″), indicating enhanced gel elasticity and viscosity during thermal processing. Scanning electron microscopy (SEM) demonstrated the formation of a compact, uniform gel network with fine pores at the optimal CaO concentration. SDS-PAGE analysis confirmed that CaO promoted transglutaminase (TGase) activity and TGase catalyzes the formation of cross-links between myosin heavy chain (MHC) and disulfide bonds. These results demonstrate the potential of eggshell-derived CaO as a sustainable, cost-effective additive to enhance surimi gel quality. Full article