Artiles
Open Access
Article
24 November 2025Bridging the Urban-Rural Divide: How Urban Agriculture Enhances Food Security in High-Urbanized Regions in Guangdong, China
The COVID-19 pandemic starkly exposed vulnerabilities in global food supply chains, highlighting the critical need for resilient, localized alternatives to ensure urban food security. Urban agriculture (UA), which we define as all agricultural output occurring in cities with an urbanization rate exceeding 85%, emerges as a pivotal strategy to mitigate such risks by shortening supply chains, particularly for perishable goods like vegetables and fruits. This study investigates the underexplored role of UA in Guangdong Province, China—a region characterized by rapid urbanization, high population density, and economic dynamism- to assess its contribution to food self-sufficiency. Leveraging a novel classification framework, we categorize Guangdong’s 21 prefecture-level cities into two groups based on an 85% urbanization threshold (2017–2022), distinguishing high-degree urbanized cities (e.g., Shenzhen, Guangzhou) from others. Using panel data, we analyze spatial-temporal patterns in grain, vegetable, and fruit self-sufficiency through geospatial and statistical methods. Key findings reveal pronounced disparities: high-degree urbanized cities exhibit critically low grain self-sufficiency, relying heavily on external supplies, while non-urbanized regions achieve exceptional surpluses. Conversely, vegetables and fruits demonstrate a center-periphery gradient, with peri-urban zones bridging the gap between urban cores and rural surplus hubs. Despite incremental gains in UA productivity, urban yields lag behind non-urban areas for grains and vegetables, though fruit production shows convergence, underscoring UA’s niche potential. These results highlight the indispensability of non-urban regions in sustaining provincial food security while emphasizing UA’s role in fresher, faster urban supply chains. We propose actionable policies, including: (1) integrating farmland protection redlines with UA incentives (e.g., vertical farming subsidies, peri-urban logistics optimization); (2) scaling technology-driven UA (controlled-environment agriculture, digital platforms); and (3) reducing post-harvest losses through urban-centric infrastructure. Our findings advance the discourse on crisis-resilient food systems, offering a replicable framework for high-density regions globally.
Open Access
Article
21 November 2025Effect of Support Preparation Method on the Performance of Ni/SrTiO3 Catalysts for Dry Reforming of Methane
Dry reforming of methane (DRM) offers an efficient route to simultaneously convert CH4 and CO2 into synthesis gas (H2/CO), a key intermediate to produce fuels and valuable chemicals. Ni-based catalysts are regarded as the most promising candidates due to their high activity and low cost; however, their stability remains a major obstacle under the DRM conditions. Perovskite-type oxides such as SrTiO3 possess high thermal stability, tunable composition, and strong metal-support interactions, making them ideal to enhance the dispersion and durability of Ni species. In this study, Ni/SrTiO3 catalysts were synthesized via co-precipitation (CP), hydrothermal (HT), and sol-gel (SG) methods, and were comprehensively characterized before and after the reaction. The characterizations revealed that all samples preserved the perovskite framework after reduction and reaction. Among them, Ni/HT-STO and Ni/SG-STO exhibited larger surface areas (18.8 and 13.9 m2·g−1) and higher initial CH4 conversions (66.3% and 68.9%) than Ni/CP-STO (44.8%). However, Ni/HT-STO underwent rapid deactivation, with CH4 conversion decreasing to 21.2% after 60 h due to severe carbon accumulation (12.4 wt%) and notable Ni particle growth. In contrast, the sol-gel derived Ni/SG-STO maintained a higher activity (25.6% after 60 h) with moderate carbon deposition (9.2 wt%) and showed the smallest Ni particle growth of only 2.64 nm (from 14.91 to 17.55 nm), compared with 4.29 nm for Ni/CP-STO (25.83 to 30.12 nm) and 6.08 nm for Ni/HT-STO (27.12 to 33.20 nm). Temperature-programmed surface reaction (TPSR) analysis further revealed that Ni/SG-STO exhibited a more balanced CH4 activation and CO2 dissociation, enabling efficient carbon-oxygen coupling and inhibiting graphitic carbon formation. Overall, these results demonstrate that the sol-gel method effectively enhances the anti-sintering and anti-coking performance of Ni/SrTiO3 catalysts.
Open Access
Review
20 November 2025Vibrational Spectroscopy in Forensic Science: A New Frontier for Biopharmaceutical Drug Authentication
The global proliferation of counterfeit biologic medicines poses a growing threat to public health and pharmaceutical integrity. Traditional laboratory-based methods for verifying drug authenticity are often time-consuming, costly, and impractical for real-time or field-based applications. This paper explores the emerging potential of infrared (IR) and Raman spectroscopy for forensic detection and authentication of biologics. While these technologies are currently underutilised in forensic science, advancements in instrumentation and data analysis are rapidly enhancing their sensitivity, portability, and usability. Focusing on protein- and peptide-based therapeutics, the paper reviews the principles and applications of IR and Raman spectroscopy, highlighting their ability to detect structural and compositional differences between authentic and counterfeit biologic drugs. The discussion emphasises the importance of interdisciplinary collaboration between forensic and biopharmaceutical sciences. As counterfeiters become more sophisticated, the integration of non-destructive spectroscopic tools into forensic workflows offers a promising path toward the rapid and reliable screening of biologic drugs in both field and laboratory settings.
Open Access
Article
19 November 2025Effects of Platform Motions on Dynamic Responses in a Floating Offshore Wind Turbine Blade
Floating offshore wind turbines (FOWTs) offer great potential for harnessing deep-sea wind energy. This study examines the effects of six-degree-of-freedom (6-DOF) platform motions on the dynamic structural responses of a FOWT blade by comparing its performance with a fixed-bottom system. Integrated aero-hydro-servo-elastic simulations for a 5-MW spar-type FOWT were conducted under various design load cases. Results indicate that the floating tower’s first-order natural frequency was about 29% higher than that of the fixed-bottom tower. Platform motions markedly influenced blade flapwise and torsional responses, with the effect intensifying under larger waves. For instance, as the significant wave height increased from 1.70 m to 9.90 m, the differences in peak response between the floating and fixed-bottom systems grew from 0.104 m to 0.363 m for blade-tip flapwise deflection, from 528.1 kN·m to 1817.4 kN·m for the root flapwise bending moment, and from 5.02 kN·m to 18.73 kN·m for the root torsional moment. In contrast, blade edgewise responses showed negligible changes, with peak deflection differences below 0.05 m. Blade loads were more sensitive to wave conditions, while platform motion magnitudes were more affected by wind. These findings offer insights into the load characteristics and structural design of FOWT blades.
Open Access
Editorial
19 November 2025Patient Safety Matters with Use of Propofol in Critically Ill Patients
Despite its tendency to produce hypotension, propofol is used widely to induce general anesthesia and to facilitate endotracheal intubation in critically ill patients. Both dose reduction and routine co-administration of vasopressors have been used to offset this unfavorable hemodynamic effect in this subset of individuals. There are potential problems associated with each of these corrective measures, however, and criticism of other intravenous hypnotics used for this purpose—particularly etomidate—may be unwarranted. Choice of the appropriate pharmacology to induce anesthesia to assist with intubation should likely be based on individual clinical assessment, together with an understanding of the drug profile and realistic adverse effects.
Open Access
Article
19 November 2025Hydrogenative Depolymerization of Polyesters Catalyzed by a PN3-Ruthenium Complex Using Both H2 and EtOH as Hydrogen Sources
Selective hydrogenative depolymerization of polyesters to diols is regarded as a promising strategy for plastics upcycling. However, many catalysts documented in literature still involve harsh reaction conditions, such as high temperature and high H2 pressure. In this work, we present a PN3-ruthenium complex catalyzed polyesters upcycling into various highly value-added diols under mild reaction conditions using H2 as a hydrogen source. It is worth noting that PLA depolymerizes into 1,2-propanediol under 1 MPa hydrogen pressure at ambient temperature within 2 h; the conditions are much milder than those of previous reports. Aromatic polyester PET degradation needs harsher reaction conditions (80 °C, 4 MPa, 3 h). The different reaction conditions enable direct separation of the degradation products of PLA and PET mixture via sequential depolymerization, as well as mixing them with polyolefins (PE, PP, PS). More strikingly, this catalyst is also effective for the catalytic hydrogenation of polyesters in the presence of ethanol to afford various diols, avoiding the use of harsh reaction conditions and an expensive autoclave.
Open Access
Article
18 November 2025Turbulent Characteristics in an Egg-Shaped Orifice Fishway and a Comparison with a Rectangular Orifice
A fishway can assist fish species in overcoming barriers to migration, which depends on the eco-hydraulic characteristics of the fishway. Based on the tail fish benefiting when at the rear of a school than when at the front, and taking into account most anadromous fish species being characterized by egg-shaped morphology, the turbulent characteristics of an egg-shaped orifice fishway were experimentally studied in a fishway flume, a comparison with a rectangular orifice fishway with the same aspect ratio was made. The results showed that the maximum longitudinal velocity for the egg-shaped orifice decays faster than that for the rectangular one, the longitudinal velocity profile exhibits two peak values, while the corresponding velocity distribution for the rectangular orifice only reveals one peak, peak values of turbulence intensity on the different horizontal plane of egg-shaped orifice occur in the orifice edges, the larger turbulence intensities still exists in the central besides the edges for the rectangular orifice, Reynolds stress reaches peak value at the orifice edges, Auto-correlation coefficient of longitudinal velocity within orifice region is of small amplitude and short period relative to the outside the orifice region, microscale eddies within the orifice region were larger than those outside, mean scale of eddy is of larger variation and shorter period, and develops outside the orifice region, frequency-spectrum of velocity fluctuation exhibits dominant frequency in the low-frequency domain.
Open Access
Article
18 November 2025Effects of Changing the Specific Surface Area in the Ceramic Matrix of CAC-Containing Refractory Castables on the Rheology and Processing
Besides the coarse and medium grain size distribution, the matrix components play a central role in the performance of refractory castables. Practical experience shows that the particle size distribution (PSD) and the specific surface area (SSA) of the ceramic matrix significantly influence processing, setting, and sintering behaviour. However, there is a lack of systematic studies on how changes in PSD or SSA affect castable properties. This study aims to address this gap by varying ceramic matrices to create model refractory castables with different matrix surface areas. Three dispersing agents with different mechanisms (electrosteric and steric) were used at graded concentrations. Results show that the SSA of the ceramic matrix has a significant influence on the rheological behaviour of refractory castables. A low SSA leads to shear thickening behaviour, a (very) low relative yield stress, and a high slump‑flow. Castables with an intermediate SSA and a multimodal composition show Bingham behaviour with a moderate relative yield stress and low relative viscosity, whereas a high SSA leads to shear thinning behaviour with a (very) high relative yield stress, (very) high relative viscosity, and a low slump-flow. Measurements of the dynamic viscosity of matrix suspensions at very low shear rates correlate with the rheological behaviour of fully composed refractory castables. Regression analysis using the Herschel‑Bulkley model successfully captures the observed qualitative relationships.
Open Access
Review
17 November 2025Enzyme-Mediated Carbon Dioxide Fixation: Catalytic Mechanisms and Computational Insights
Carbon conversion technologies that transform carbon dioxide (CO2) into high-value chemicals are pivotal for achieving sustainability. Among these, enzyme-mediated CO2 fixation has recently gained increasing attention as a more sustainable and environmentally friendly alternative to traditional chemical methods, which typically require harsh conditions and impose significant environmental costs. Recent advances in computer-aided techniques have greatly facilitated the mechanistic understanding of CO2-fixing enzymes and accelerated the development of enzyme-catalyzed carboxylation strategies. This review highlights recent progress in enzyme-mediated CO2 fixation by categorizing key enzymes into four classes based on their cofactor or metal ion requirements: cofactor-independent enzymes, metal-dependent enzymes, nicotinamide adenine dinucleotide phosphate (NAD(P)H)-dependent enzymes, and prenylated flavin mononucleotide (prFMN)-dependent enzymes. We outline the basic principles and applications of molecular dynamics (MD) simulations and quantum mechanical (QM) calculations, which serve as essential tools for investigating enzyme conformational dynamics and reaction mechanisms. Through representative case studies, we demonstrate how computational analyses uncover catalytic features that enhance CO2 conversion efficiency. These insights underscore the critical role of computer-aided approaches in guiding the rational design and optimization of biocatalysts, thereby advancing the application of enzyme-based systems for CO2 fixation.
Open Access
Article
17 November 2025Effect of the Temperature within the Building Chamber on the Tensile Strength of TPU and ABS Materials
Fused deposition modeling (FDM), also known as fused filament fabrication (FFF), is the most widely used additive manufacturing technique because it offers several key advantages: material flexibility, low cost, high prototyping precision, and ease of use. The mechanical properties of 3D printed products depend on many factors, and one of the most important is the complete control over the temperature within the building chamber. However, research on the influence of chamber temperature is still minimal. This research probes the impact of chamber temperature on the mechanical properties of the printed material, precisely the thermoplastic polyurethane (TPU) and acrylonitrile butadiene styrene (ABS) materials, by using the FFF printing method. This research analyzes the tensile strength of TPU and ABS printing materials by testing printed samples at three different building chamber temperatures (30, 45, and 60 °C). From the analysis data, the study shows that the effect of building chamber temperature on tensile strength of printed parts, and also recommends that to have the best tensile strength for printed parts, the building chamber temperature of both TPU and ABS should be between 30 and 45 °C.
