Global Challenges最新文献

Thermoset polymers with permanently cross-linked networks have outstanding mechanical properties but cannot be reprocessed or recycled. Vitrimerization is a simple and practical method to convert permanent crosslinked thermosets into vitrimers with covalent adaptable networks, which can be recycled. Vitrimerization is a mechanochemical strategy to convert thermosets into vitrimers by using a ball milling system. In this study, we propose solid-state shear extrusion (SSSE) as a continuous, room-temperature route to replace ball milling (BM) for epoxy vitrimerization. The vitrimerized thermosets obtained using the SSSE process exhibit comparable activation energy and mechanical properties with the vitrimers obtained using the BM method. In addition, the SSSE vitrimers can be reprocessed multiple times, maintaining above 80 percent in mechanical properties. This first feasibility study of employing SSSE for vitrimerization may establish it as a scalable, energy-efficient alternative to batch BM for industrial, closed-loop recycling of thermosets with the least environmental impact.

Addressing energy and water management in rural Mozambique is essential for sustainable agricultural development. This study focuses on Nampula Province, where limited access to these resources deepens socioeconomic and environmental challenges. The research promotes sustainability by identifying, planning, and implementing innovative and socially validated solutions to enhance the water-energy nexus for agricultural growth. In this study, an integrated approach combining geographic information system (GIS) tools and participatory methods is developed to assess and address local needs. The initial phase involved analyzing the rural context through field surveys, stakeholder interviews, community workshops, and site visits to collect and validate data, using tailored questionnaires and digital platforms. In the second phase, collected data are processed using GIS, building a geodatabase with layers such as land use, crop distribution, water demand, energy needs, and locations of processing facilities. QGIS software is used to map resource potential, deficits, and spatial disparities. These analyses provide key insights to guide sustainable interventions, helping identify critical areas and opportunities for optimizing resource use. This integrated and participatory approach can efficiently ensure the development of solutions that are contextually appropriate, technically robust, and socially validated, thereby laying the groundwork for effective and sustainable resource management strategies in Nampula.

Irrigation is a critical component of smallholder agriculture, particularly in regions prone to climatic variability and water scarcity, such as Mozambique. This study investigated the challenges faced by smallholder farmers in accessing water for irrigation, explored the adaptation strategies they have adopted, and evaluated the effectiveness of these approaches in enhancing agricultural productivity and resilience. Using quantitative methods, the study highlights significant disparities in water access across the districts of Chókwè, Mandlakazi, and Guijá. Key findings include an ageing farmer population, limited access to efficient irrigation technologies, inadequate irrigation infrastructure, and the increasing impact of climate change, particularly in the form of droughts. Farmers primarily rely on gravity flow irrigation systems, but the lack of sufficient water storage and drainage infrastructure impedes effective water use. The study also identified crucial adaptation strategies, including the rehabilitation of irrigation systems, the adoption of solar-powered irrigation technologies, and the promotion of climate-resilient agriculture practices. The study emphasized the need for policy interventions focused on investing in irrigation infrastructures and providing capacity-building programs to enhance water management and climate adaptation. These findings are vital for informing policies aimed at improving water access and resilience in smallholder farming systems in Gaza province and similar regions.

Hybrid Perovskite Solar Cells (HPSCs) using lead halide perovskites offer high performance and low-cost fabrication via solution processes. However, their environmental and thermal instability, along with poor polycrystalline quality—such as trap states and grain boundaries—limit device efficiency. In this study, we propose four novel compositions of carbon nanoparticles (CNPs) as additives for methylammonium PbI₃ (MAPI)-based HPSCs to enhance the optoelectronic performance. The CNPs are synthesized through a green, cost-effective method using citric acid and L-tryptophan for nitrogen doping. Their optical, structural, and morphological properties are thoroughly characterized prior to integration. To assess the impact of CNPs on perovskite crystallization and facet orientation, synchrotron-based 2D Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS) is employed. Devices are fabricated using an inverted architecture, suitable for flexible substrates and energy-efficient processing. Electrical and electrochemical impedance spectroscopy analyses reveal improved fill factors across all CNP compositions. The optimized system achieves a power conversion efficiency (PCE) of 10%, compared to 8.2% for the reference device without CNPs, confirming the potential of green CNPs to enhance HPSC performance without compromising structural integrity.

This research focuses on designing a novel, five-layered N95 mask fabric that integrates the natural antimicrobial properties of Boswellia serrata, thereby unlocking a new dimension in respiratory protection. Specifically, the second and third layers of the mask fabric were coated with a chloroform extract of Boswellia serrata to impart layer-specific functionality. The functionalized mask fabrics underwent rigorous analysis, including Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and wettability measurements, confirming the successful incorporation of the extract. The contact killing assay demonstrated a highly effective dual-action defense system. The extract-coated second layer exhibited a rapid, but transient, antimicrobial effect, showing excellent inhibition within one hour (92% against S. aureus, 86% against E. aerogenes), though this effect diminished significantly by eight hours. In contrast, the third layer provided a prolonged and sustained antimicrobial effect, maintaining high inhibition even after eight hours (100% against C. albicans and K. pneumoniae, and 90% against E. aerogenes). Maximum killing efficiency was observed at four hours for both layers. This innovative application of layer-specific engineering offers enhanced and prolonged protection against airborne pathogens, marking a significant leap in mask technology.

It is unclear how Micrococcus adapts to leaf environments and why it exhibits exceptionally high heavy-metal tolerance. Herein, we report that a Micrococcus strain isolated from camphor tree leaves forms previously undescribed sponge-like biofilms and a capsule with a distinctive honeycomb-like Voronoi structure. Capsule formation begins during cell division, wherein thin fibers appear between two dividing cells and gradually thicken to form a dense capsule. The capsule surface is densely perforated with cavities (95.0 ± 4.41 nm in diameter and 166.3 ± 5.91 nm in depth), resembling a Voronoi diagram. As the structure matures, filamentous connections between cells form sponge-like biofilms. Energy-dispersive X-ray spectroscopy analysis revealed that these architectures retain essential metal ions, while limiting the uptake of toxic copper ions. These structures represent a novel defense strategy, distinct from conventional mechanisms in which heavy metals are directly adsorbed into cells or capsules. This structural strategy supports copper resistance and ecological adaptation on camphor tree leaves, where microorganisms encounter nutrient limitations and fluctuating moisture. Building upon these insights, our findings expand current understanding of microbial survival strategies, shows the importance of structural biology in the phyllosphere, and indicates potential applications in bioremediation.

Plant diseases, agricultural intensification, and climatic catastrophes such as drought have all has a significant impact on agricultural production in recent years. For decades, synthetic agrochemicals have been the primary tool for disease management and yield enhancement. However, their use poses significant environmental and health risks. There are many studies on plant growth-promoting rhizobacteria (PGPR) and bacterial biocontrol agents (BCA) as eco-friendly alternatives to synthetic agrochemicals. This review synthesizes current knowledge on the direct and indirect mechanisms by which PGPR and BCA enhance tomato growth and suppress pathogens. Although some of these PGPR and BCA are known, their mechanisms are not completely understood. Emerging omics approaches, which include genomics, transcriptomics, proteomics, and metabolomics, are highlighted as powerful tools for elucidating plant-microbe interactions and guiding next-generation biocontrol strategies. By critically examining overlapping mechanisms and applications, this review clarifies the complementary roles of PGPR, BCA, and “omics” and identifies research gaps for more consistent and scalable use in agriculture.

This randomized crossover trial investigates the effects of blue light defocus display technology on refractive status, axial length (AL), retinal blood flow, and visual function in adults. Twenty-one participants completed all four interventions: 0D, 1D, 2D defocus, and 1D defocus with 30 % blue light filtering (1D+BLF) in a randomized order during standardized visual tasks. Pre- and post-task assessments include refraction, AL, choroidal thickness (ChT), retinal defocus, reading efficiency, and visual fatigue. Results demonstrate that 1D defocus reduces spherical equivalent refraction (SER) (−4.35 ± 2.66 D to −4.21 ± 2.66 D, P = 0.045) and increases ChT (P = 0.003), while 1D+BLF induces axial elongation (P = 0.026). Both 1D and 2D defocus are linked to increased ChT, whereas 0D and 1D+BLF groups exhibited hyperopic defocus trends. Reading speed and efficiency improve in the 1D group (p < 0.05), while visual fatigue and blink frequency increase significantly in the 0D group (p = 0.001). Linear regression identifies correlations between defocus and changes in choroidal volume, near convergence, and fusional reserves. These findings suggest blue light defocus technology may help mitigate hyperopic defocus, influence retinal perfusion, and alleviate visual fatigue, supporting its potential role in myopia prevention. Further validation in diverse populations and long-term studies is warranted.

Extreme temperature events, particularly heatwaves, are intensifying due to climate change and urbanization, posing major public health challenges in Central Asia (CA), where research is limited. Despite the rising frequency and severity of heat extremes, long-term assessments of their health impacts are scarce. This study addresses this gap by analyzing historical and future heatwave trends and associated health risks using multi-ensemble climate models across 700 locations from 1959 to 2100. Bias correction improved GCMs, reducing bias and RMSE by 24% and 14%, respectively. Under SSP2–4.5, projected heatwave magnitudes (HWM) shift from 26 to 31 °C, consistent with historical moderate to severe events. Under SSP5–8.5, HWM increases to 29–36 °C. Turkmenistan is expected to experience ultra-extreme heatwaves in the far future, a pattern not seen in other CA countries. Under SSP2–4.5, Kazakhstan and Uzbekistan show the highest rises in heatwave-related mortality rates, with slopes of 5.432 and 3.021 in the near future, declining to 1.377 and 1.102 in the far future. SSP5–8.5 shows similar but higher estimates, highlighting escalating public health risks. Findings emphasize the urgent need for region-specific climate policies and public health strategies to mitigate the growing burden of extreme heat in CA.

The widespread Presence of emerging contaminants (ECs) from pharmaceuticals, personal care products, and industrial, agricultural, and urban chemicals/wastes has escalated into a pressing global health concern. Key ECs include per- and polyfluoroalkyl substances (PFAS), microplastics, certain nanomaterials, endocrine disrupting compounds, and pesticides spanning diverse chemical classes, with harmful implications for humans, animals, and the environment. They have been detected in groundwater, surface water, soils, and wastewaters in different concentrations. Bioremediation has been well praised as a green, ecofriendly method among other methods for environmental remediation. Laccase (Lac), a versatile oxidative enzyme, is distinguished by its ability to act on non-phenolic substrates, thereby expanding its utility in EC breakdown. This review delves into the origins of ECs and investigates the pivotal role of Lac in their degradation. Lac is one of the most powerful natural oxidative enzymes and is presently receiving the attention of the science community as an effective and versatile green catalyst for eco-powered cleanup of various contaminants. This review analyses the complex mechanisms behind Lac-mediated degradation and underscores its promise in promoting sustainable water/land resource management. While its wide use still faces different challenges, innovative methodologies such as Lac immobilization are highlighted as effective approaches for enhancing EC removal and advancing environmental conservation. In essence, the review spotlights the ecological implications of Lac in bioremediation and the transformative approaches for its sustainable applications. Through cutting-edge techniques and strategic enzyme deployment, this review offers a forward-looking perspective on Lac in mitigating EC-induced environmental challenges.