Global Challenges最新文献

Carbon nitride quantum dots (CNQDs) are emerging as versatile photocatalytic materials with promising applications in biomedicine and environmental remediation. In this study, we synthesized pristine and sulfur-doped CNQDs via a hydrothermal method, and characterized them using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis absorption spectroscopy. For the first time, the quantum yields of superoxide and singlet oxygen generation were measured for CNQDs. Sulfur doping was found to significantly enhance superoxide generation while concurrently suppressing singlet oxygen production, offering a powerful mechanism for tailoring reactive oxygen species (ROS) output. In addition, all CNQD samples produced hydrogen peroxide and hydroxyl radicals. The ability of these nanomaterials to produce multiple ROS types underscores their potential as hypoxia-resistant photosensitizers (PSs) for photodynamic therapy (PDT) and as efficient photocatalysts for pollutant degradation.

This study explores a dual-use CO₂-breathing plasma thruster capable of operating in very low Martian orbits (80–160 km), delivering electric propulsion and in situ oxygen generation. Experimental results demonstrate a thrust of over 1 N at input powers ranging from 0.1 to 1 kW across varying discharge frequencies. Optical emission spectroscopy reveals strong emission at 777.1 nm corresponding to atomic oxygen, along with spectral features of CO and CO₂, confirming the effective dissociation of CO₂ within the plasma. These findings support the viability of propulsion systems as multifunctional platforms for future Mars missions, enabling both aerial/ground mobility and human habitats without stored propellant gas.

Research in global health is often framed as centering health equity. However, research and programmatic partnerships are often relationships between institutions and researchers in high-income countries (HICs), and researchers and actors in low- and middle-income countries (LMICs), including many countries in Sub-Saharan Africa (SSA). Such relationships are rife with power dynamics that require thoughtful attention and solutions. Feminist research methods, including perspectives from intersectional and African feminist thinkers, as well as participatory approaches, may offer a means of engaging with power inequities and disrupting often taken-for-granted assumptions in the SSA context. Such epistemological perspectives and methods not only disrupt “traditional” research relationships and challenge unexamined assumptions about knowledge but are also driven by the lived experiences of health disparities in specific, formerly colonized contexts and can therefore lead to context-specific or localized solutions to complex health inequities. This paper explores how these specific feminist research perspectives and methods can challenge power dynamics that are often embedded in global health research and interventions in SSA.

Copper-based oxides, including Cu₂O, CuO, CuBi₂O₄, CuFeO₂ and CuFe₂O₄ have emerged as promising photocathode materials for solar-driven photoelectrochemical (PEC) reduction reactions such as hydrogen evolution (HER), carbon dioxide reduction (CO₂RR), and nitrogen reduction (NRR). Their appeal lies in the combination of their earth-abundance, low toxicity, and suitable optoelectronic properties. However, the practical deployment of these materials is hindered by their intrinsic instability under operating conditions, primarily due to photocorrosion, interfacial charge recombination, and limited carrier transport. This review provides a comprehensive overview of recent strategies developed to improve the stability of the most studied Cu-based photocathodes in relevant reported works. Specifically, seven key approaches are discussed: (i) optimization of electrical contact with the substrate, (ii) use of hole-selective layers, (iii) electron-extraction overlayers, (iv) protective coatings, (v) surface passivation strategies, (vi) integration of co-catalysts, and (vii) synergistic strategies. Particular emphasis is placed on how each strategy addresses specific degradation mechanisms, and how synergistic combinations can enable durable and efficient PEC operation. Finally, the present review outlines current challenges related to scalability, fabrication compatibility, and real-world durability, and highlights emerging directions in materials design and device integration. Unlike previous reviews that predominantly compare device efficiencies, this work places stability at its core, providing a strategy-oriented perspective on how Cu-based photocathodes can be made durable under operational conditions. By systematically connecting structure, interface, and function, this work aims to guide the development of robust Cu-based photocathodes for sustainable solar fuel production.

The frequent detection of microplastics (MPs) in bottled drinking water underscores the need for effective point-of-use (POU) purification strategies to limit human exposure, particularly given their ability to transport co-contaminants. While metal-organic frameworks (MOFs) have been extensively investigated for MP removal, their application in practical POU drinking water purification remains largely underexplored, especially regarding scalability and delivery of potable water after filtration. In this work, NH₂-MIL-101(Fe) MOF is integrated onto a commercial polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane to develop a Fe-MOF@UF composite for enhanced removal of polyethylene terephthalate (PET)-MP from drinking water. The optimally synthesized Fe-MOF@UF membrane achieved a PET-MP rejection efficacy of ∼94%. Additionally, its practical applicability is validated using commercially available PET-bottled drinking water, confirming the effective removal of MPs while delivering potable water compliant with international drinking water quality standards. Collectively, these outcomes emphasize the first practical viability of MOF-membrane hybrids for POU drinking water treatment. Despite limitations, this research lays a strong groundwork for future efforts toward performance optimization and highlights a viable pathway for scalable, cost-effective, and sustainable MOF-incorporated household MP filtration units.

Hepatocellular carcinoma (HCC) remains the most prevalent primary liver cancer, characterized by alarmingly high mortality rates and low five-year survival outcomes. A significant challenge in HCC management lies in its advanced-stage treatment, with most cases identified at advanced, unresectable stages, resulting in poor prognoses and limited treatment options. Over the last decade, considerable advancements have been made in systemic treatment strategies, notably with the introduction of multi-kinase inhibitors such as sorafenib and lenvatinib, which have redefined the therapeutic landscape for advanced HCC. The emergence of immunotherapy has further revolutionized first-line treatment, bringing new hope with agents like the PD-1 inhibitor nivolumab and the CTLA-4 inhibitor tremelimumab. Moreover, combination regimens such as atezolizumab plus bevacizumab have demonstrated remarkable clinical efficacy, leading to substantial improvements in overall survival and progression-free survival. Despite the availability of multiple treatment options, clinical trial outcomes remain suboptimal. Key challenges persist in the selection and sequencing of therapies, the development of more diversified combination strategies, and the implementation of downstaging approaches for advanced HCC. This paper aims to provide a comprehensive review of the current progress in systemic therapies for HCC, drawing on extensive research findings and clinical trial data to assess their clinical applications and explore potential challenges. By offering a critical analysis of these therapeutic strategies, this paper seeks to furnish valuable insights and references for ongoing research and future clinical practice, ultimately contributing to improved outcomes in HCC management.

Accurate prediction of optical performance in solar cells with multiscale-textured interfaces is essential for optimizing light management in next-generation photovoltaics. For the first time, a systematic validation of two complementary modeling approaches is carried out on experimentally fabricated thin-film silicon (TF Si) solar cells: rigorous coupled-wave analysis (RCWA), offering a full electromagnetic solution but constrained by boundary conditions, and a ray optics model, operating in the refractive regime. The study involves two device architectures: an a-Si:H single-junction cell on commercial Asahi VU-type glass with random nanotextures, and an nc-Si:H single-junction cell on novel micro-periodic honeycomb-textured glass developed in-house. Simulated and measured external quantum efficiency (EQE) and total front reflection losses (1-R) are benchmarked using the root mean squared error (RMSE). The ray model shows deviations of only 2%–6%, comparable to RCWA, while reducing computation time from 1 week to less than 30 min. Applied to an a-Si:H/nc-Si:H tandem device on honeycomb-textured glass, ray optics reproduced the optical response with spectral deviations below 6% and photocurrent mismatch under 0.2 mA/cm². These findings uniquely establish ray optics, when combined with accurate optical constants and realistic interface morphologies, as a reliable and computationally efficient predictive tool broadly transferable to thin-film technologies, including perovskites.

The cover image is based on the article CytroCell@Nafion: Enhanced Proton Exchange Membranes by Mario Pagliaro etal., https://doi.org/10.1002/gch2.202500338.

The cover image is based on the article Blue Light Defocus Induces A Positive Effect on Refractive Status and Ocular Health: A Randomized Crossover Trial by Zi-Bing Jin etal., https://doi.org/10.1002/gch2.202500222.

Drought is a prolonged lack of rainfall that causes water shortages for agricultural land by reducing soil moisture and limiting crop yields. This study assesses the impacts of drought in Erbil, Iraq, using 28 years of data from the southern, central, and northern regions. A soil-water-balance framework integrates precipitation with reference evapotranspiration (ETo), crop evapotranspiration (ETc), and actual evapotranspiration measures to address seasonal water deficits. According to the Standardized Precipitation Index (SPI), the area experienced basin-wide droughts in 1998-2000, 2007-2009, a renewed event in 2020-2021, and significant negative anomalies in 2024-2025. Analyzing drought frequency shows that "near-normal" conditions are most common (around 57%-79%), with occasional moderate to extreme events. The study reveals that winter wheat undergoes severe stress, with ETc reaching 200-250 mm month during dry years and ETa dropping to 15-30 mm/month, resulting in June deficits of nearly 277 mm. It also notes high variation in annual precipitation, with coefficients of variation (CV) ranging from 26.1% to 51.7%. ARIMA (1,0,1) models suggest weak persistence and zone-specific accuracy, with MAPE values of 37.8% in the south, 33.9% in the central region, and 28.8% in the north. The results underscore the importance of climate-resilient water and agricultural planning.