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23 pages, 816 KB  
Article
Learning Landscapes to Promote Environmental and Social Skills in Higher Education: A Proposal Aligned with SDG 11 (Sustainable Cities and Communities)
by Rafael Marcos-Sánchez, Alexandra Miguez-Souto, Alicia Zaragoza-Benzal and Daniel Ferrández
Sustainability 2026, 18(6), 2999; https://doi.org/10.3390/su18062999 - 18 Mar 2026
Abstract
In the contexts of higher education and Education for Sustainable Development, universities face the challenge of preparing professionals capable of addressing complex urban issues related to Sustainable Development Goal 11 (SDG 11). Learning landscapes, grounded in the theory of Multiple Intelligences and Bloom’s [...] Read more.
In the contexts of higher education and Education for Sustainable Development, universities face the challenge of preparing professionals capable of addressing complex urban issues related to Sustainable Development Goal 11 (SDG 11). Learning landscapes, grounded in the theory of Multiple Intelligences and Bloom’s Taxonomy, have been proposed as a pedagogical framework to support the development of sustainability competencies and higher-order thinking; however, evidence regarding their applicability and viability in university teaching remains limited. This study examines an exploratory learning landscape–based training experience oriented toward SDG 11, focusing on university faculty perceptions. A design-based research approach with mixed-methods design was employed, emphasizing the co-construction, pilot implementation, and formative assessment of learning landscapes within a technical-scientific faculty development program. The results indicate generally positive faculty perceptions, particularly in terms of satisfaction, perceived learning, and professional development. Participants also reported pedagogical usefulness and perceived potential to enhance student motivation and engagement. However, stable curricular integration emerged as the main challenge, mainly due to design workload and the need for institutional support. Overall, the findings provide initial empirical evidence on the perceived value and limitations of learning landscapes in sustainability-oriented higher education and point to the need for further research and institutional conditions to support their implementation. Full article
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21 pages, 6456 KB  
Article
Design of Functionalized Biochars for Dual Wastewater Treatment and Fertilizer Production
by Fernanda Pantoja, Sándor Beszédes, Tamás Gyulavári, Erzsébet Illés, Gábor Kozma and Zsuzsanna László
Water 2026, 18(6), 717; https://doi.org/10.3390/w18060717 - 18 Mar 2026
Abstract
Wastewaters from the food industry and domestic sources contain large amounts of ammonium, a major contributor to eutrophication. Recovering this nutrient for fertilizer use offers both environmental and agricultural benefits. Poplar chop-derived biochars were prepared under different pyrolysis temperatures (300–500 °C) and chemical [...] Read more.
Wastewaters from the food industry and domestic sources contain large amounts of ammonium, a major contributor to eutrophication. Recovering this nutrient for fertilizer use offers both environmental and agricultural benefits. Poplar chop-derived biochars were prepared under different pyrolysis temperatures (300–500 °C) and chemical modifications (acidic and alkaline) to optimize ammonium (NH4+) adsorption and fertilizer reuse. The biochars were characterized by zeta potential, SEM–EDX, FTIR, and specific surface area measurements. Batch adsorption tests revealed that the alkaline-modified biochar produced at 300 °C achieved the highest capacity (4.63 mg NH4+/g biochar) and 62% removal efficiency. Adsorption kinetics followed a pseudo-second-order model (R2 = 0.97) but showed only marginal differences among models without independent mechanistic evidence. The Temkin isotherm described the equilibrium data the best (R2 > 0.99). Ammonium-enriched biochars enhanced seed germination by up to 54% compared to the control and increased plant biomass up to 12-fold in pot experiments. These results demonstrate that optimized biochars can effectively recover ammonium from wastewater; moreover, the observed plant growth improvement suggests potential slow-release behavior, promoting nutrient recycling and sustainable agriculture. Full article
(This article belongs to the Topic Waste-Based Materials for Environmental Remediation)
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45 pages, 2650 KB  
Systematic Review
A Systematic Review on Amnion as a Cell Delivery Scaffolding Material for Cartilage Regeneration in Pre-Clinical and Clinical Studies
by Shu-Yong Liow, Sik-Loo Tan, Alvin Jiunn-Hieng Lu, Kwong Weng Loh, Seow Hui Teo, Chan Young Lee, Le Wan, Azlina Amir Abbas and Kyung-Soon Park
Bioengineering 2026, 13(3), 357; https://doi.org/10.3390/bioengineering13030357 - 18 Mar 2026
Abstract
Cartilage is an important yet vulnerable tissue with limited self-healing capacity, where damage often progresses to joint degeneration, which eventually leads to severe osteoarthritis (OA). Current tissue engineering strategies focus on biocompatible scaffolds for cartilage regeneration, particularly amnion (or amniotic membrane), emerging as [...] Read more.
Cartilage is an important yet vulnerable tissue with limited self-healing capacity, where damage often progresses to joint degeneration, which eventually leads to severe osteoarthritis (OA). Current tissue engineering strategies focus on biocompatible scaffolds for cartilage regeneration, particularly amnion (or amniotic membrane), emerging as a promising biomaterial due to its wide availability, low immunogenicity, and naturally derived microenvironment that is advantageous for cartilage regeneration. This systematic review aims to evaluate the existing evidence on the efficacy of amnion as a tissue scaffolding material for cartilage regeneration in both preclinical and clinical studies. Using terms such as “cartilage damage”, “cartilage injuries”, “amnion” and “amniotic membrane”, 19 relevant studies were identified across three major databases (PubMed, Scopus and Web of Science) until 25 December 2025. All preclinical and clinical studies that utilized amnion for cartilage repair or as cartilage tissue engineering scaffolding materials were included. Evidence quality was assessed using the OHAT and MINORS risk of bias tool. This study is prospectively registered in the PROSPERO database under the ID 1178444. The findings consistently indicate that amniotic scaffolds, regardless of processing methods or cell seeding, yield favorable outcomes without adverse effects across different species. In vitro analysis revealed that treatment groups with amnion show better cell attachment, viability, and proliferation, and higher content of cartilage-related markers expressed by the seeded cells, either chondrocyte, bone marrow-derived mesenchymal stem cells (MSCs), adipose tissue-derived MSCs, placenta-derived MSCs, umbilical cord-derived MSCs, amniotic MSCs or amniotic epithelial cells. In in vivo and ex vivo studies, amnion-treated groups demonstrated improved quality of the treated cartilage, with better integration, as indicated by higher histological scores and the presence of type II collagen (COL-II). There was an inconsistency in the reporting of cartilage defect dimensions in the in vivo models across the different studies. Nevertheless, the outcome measurements were consistently reported with histological analysis, with or without International Cartilage Repair Society (ICRS) scoring and immunohistochemistry (IHC) analysis, across the studies. Clinically, most subjects show improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) Sports and Recreation score and KOOS Quality of Life score, as well as reduced Visual Analogue Scale (VAS) average and maximum pain scores. In conclusion, preclinical and clinical studies support amnion as an ideal scaffold material for cartilage tissue engineering and regeneration. Future research should focus on optimizing and standardizing amnion scaffold preparation at a production scale to facilitate the translation of these positive outcomes into clinical applications. This study is funded by the Ministry of Higher Education Malaysia via Prototype Research Grant Scheme (PRGS/1/2021/SKK01/UM/02/1) and UM International Collaboration Grant—2023 SATU Joint Research Scheme Program: ST007-2024. Full article
17 pages, 1301 KB  
Article
Preparation and Performance Evaluation of a Supramolecular Gel Plugging Agent for Severe Lost Circulation Gas Reservoirs
by Yingbiao Liu, Kecheng Liu, Tao Zeng, Xuyang Yao, Weiju Wang, Huijun Hao, Zhangkun Ren and Jingbin Yang
Gels 2026, 12(3), 256; https://doi.org/10.3390/gels12030256 - 18 Mar 2026
Abstract
The plugging of fractured gas reservoirs with severe lost circulation during oil and gas drilling and production has long been challenged by technical issues such as low plugging strength and short effective duration. This paper reports the preparation of a high-strength supramolecular gel [...] Read more.
The plugging of fractured gas reservoirs with severe lost circulation during oil and gas drilling and production has long been challenged by technical issues such as low plugging strength and short effective duration. This paper reports the preparation of a high-strength supramolecular gel plugging agent via micellar copolymerization based on the synergistic effects of hydrophobic association and hydrogen bonding. Systematic optimization determined the optimal synthesis formula: acrylamide (AM) 12%, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) 2%, stearyl methacrylate (SMA) 0.4%, sodium dodecyl sulfate (SDS) 1.5%, and potassium persulfate 0.3%, with a reaction temperature of 60 °C. Performance evaluations revealed that the gel possesses a controllable gelation time (120 min) and excellent viscoelastic recovery properties. At a compressive strain of 87%, the compressive stress reached 1.43 MPa while maintaining structural integrity. Swelling behavior analysis indicated that the gel follows a non-Fickian diffusion mechanism, with its swelling process governed by the synergistic interplay of water molecule diffusion and polymer network relaxation. Core plugging experiments demonstrated that the gel achieved plugging efficiencies exceeding 95% for cores with permeabilities ranging from 0.18 to 0.90 μm2, with a maximum breakthrough pressure gradient of up to 11.48 MPa/m. These results highlight the gel’s efficient and broad-spectrum plugging capability for fractured lost circulation zones. This preliminary study provides experimental foundations for the material design and performance optimization of supramolecular gel-based long-lasting plugging agents for severe lost circulation gas reservoirs, and further field-scale validation is required for engineering application. Full article
(This article belongs to the Topic Polymer Gels for Oil Drilling and Enhanced Recovery)
20 pages, 2702 KB  
Article
Mathematical Modeling of Microbial Hydrocarbon Degradation Using Analytical and Runge–Kutta Methods
by Cristian Mugurel Iorga, Gabriel Murariu and Lucian Georgescu
Processes 2026, 14(6), 973; https://doi.org/10.3390/pr14060973 - 18 Mar 2026
Abstract
Petroleum hydrocarbons remain major environmental contaminants, and understanding the mechanisms governing their biodegradation is essential for designing effective remediation plans. The strategy in this article is slightly different from other cases in the literature. Such literature models require, for their elaboration, a significant [...] Read more.
Petroleum hydrocarbons remain major environmental contaminants, and understanding the mechanisms governing their biodegradation is essential for designing effective remediation plans. The strategy in this article is slightly different from other cases in the literature. Such literature models require, for their elaboration, a significant number of experiments; the number of experimental determinations is at least proportional to the square of the number of constants introduced in the mathematical expressions. For this reason, the strategy followed in this article is different—starting from a set of experiments carried out and presented in a coherent and published manner, a simple methodology for building specific and minimal models, which will allow solving specific problems, was effectively developed. This study develops a nonlinear mathematical structure, expressed as a system of coupled differential equations, that simultaneously describes the degradation of petroleum hydrocarbons and the dynamics of hydrocarbon-degrading bacteria and fungi in soil–sludge mixtures. The model was calibrated using experimental data obtained from biopiles prepared with different volumetric ratios of contaminated soil and sewage sludge. Approximate analytical solutions were derived and the distributed constants were evaluated. For a consistent discussion, the analytical solutions were assessed against numerical desk simulations performed with a classical fourth-order Runge–Kutta method, which accurately reproduced the nonlinear behavior of the specific system. This numerical approach was chosen in order to overcome the proper difficulties encountered in this strategy implementation. The results show that the soil–sludge ratio strongly influences biodegradation efficiency, while kinetic parameters determine whether microbial communities evolve toward a stationary regime or accelerated contaminant removal. The combined analytical–numerical framework provides a robust predictive tool for optimizing mixture composition and improving the design of bioremediation treatments for petroleum-contaminated soils. Full article
(This article belongs to the Special Issue Innovations in Solid Waste Treatment and Resource Utilization)
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36 pages, 657 KB  
Review
Family Support in Healthy Dietary Behaviours Among Community-Dwelling Older Adults: A Scoping Review
by Pui Ying Mak, Stefanos Tyrovolas and Justina Yat Wa Liu
Nutrients 2026, 18(6), 963; https://doi.org/10.3390/nu18060963 - 18 Mar 2026
Abstract
Background: Healthy dietary behaviours are essential for maintaining health, functional independence, and quality of life in later life. Family members are a key source of social support for community-dwelling older adults, yet the ways in which family support shapes older adults’ dietary [...] Read more.
Background: Healthy dietary behaviours are essential for maintaining health, functional independence, and quality of life in later life. Family members are a key source of social support for community-dwelling older adults, yet the ways in which family support shapes older adults’ dietary behaviours, particularly among those who retain autonomy, remain insufficiently synthesized. Therefore, this review aims to map how family support influences dietary behaviours among community-dwelling older adults by examining the forms, roles, and contextual influences of family support within a Social Support Theory framework. Methods: Following Joanna Briggs Institute guidance and PRISMA-ScR reporting standards, we conducted a scoping review of empirical studies published in English or Chinese. Searches were conducted across PubMed, CINAHL, PsycINFO, Web of Science, and Scopus from inception to 2025. Quantitative and qualitative evidence was synthesised using a convergent–segregated mixed-methods approach. Qualitative findings were deductively mapped to instrumental, informational, emotional, and esteem support domains. Results: Nineteen studies were included. Quantitative evidence indicated that family support, particularly shared meal preparation, joint dietary adherence, and autonomy-supportive encouragement, was generally associated with better diet quality, dietary adherence, and nutritional outcomes. Qualitative findings showed that the influence of family support depended on relationship dynamics and contextual factors, including communication patterns, autonomy negotiation, shared responsibility, and cultural expectations. Conclusions: Family support plays a multifaceted and context-dependent role in shaping dietary behaviours among community-dwelling older adults. These findings can inform the development of family-inclusive strategies and interventions that promote healthy dietary behaviours while respecting older adults’ autonomy and relational contexts. Full article
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28 pages, 4809 KB  
Article
Exploring the Multifaceted Phytochemical Profile of Nigella sativa and the Therapeutic Potential of Thymoquinone
by Mohamed A. Fareid, Gamal M. El-Sherbiny, Nancy M. Elafandy, Nagat E. Eltoum, Mohamed S. Othman, Mohamed Shawky, Ahmad S. El-Hawary, Fatma A. Hamada and Amira Salah El-Din Youssef
Pharmaceuticals 2026, 19(3), 503; https://doi.org/10.3390/ph19030503 - 18 Mar 2026
Abstract
Background: Nigella sativa (black cumin) seeds are renowned for their ethnomedicinal significance and are rich in bioactive phytochemicals, which contribute to food preservation and the prevention of various diseases through their antimicrobial and antioxidant properties. Accordingly, this study aimed to characterize the [...] Read more.
Background: Nigella sativa (black cumin) seeds are renowned for their ethnomedicinal significance and are rich in bioactive phytochemicals, which contribute to food preservation and the prevention of various diseases through their antimicrobial and antioxidant properties. Accordingly, this study aimed to characterize the phytochemical composition of N. sativa seed extracts, isolate thymoquinone, and assess their antibacterial, antibiofilm, antioxidant, anti-inflammatory and antidiabetic activities. Methods: Nigella sativa seed extracts were prepared using solvents of increasing polarity and analyzed for phytochemical content. Metabolite profiling was performed using UHPLC/QTOF-MS. Thymoquinone, the major constituent, was isolated via thin-layer chromatography (TLC), further purified using semi-preparative reverse-phase high-performance liquid chromatography (RP-HPLC), and evaluated in vitro for antibacterial, antibiofilm, antioxidant, anti-inflammatory, and antidiabetic activities. Results: Extraction yields ranged from 5.5% to 8.4% (w/w), with methanol yielding the highest phenol (6.34 ± 0.31 mg GAE/mL) and flavonoid (5.12 ± 0.26 mg QE/mL) contents. UHPLC/QTOF-MS revealed a chemically diverse profile dominated by thymoquinone (58% relative abundance), alongside p-cymene, carvacrol, longifolene, and nigellidine. Thymoquinone (Rf = 0.56) was initially isolated from the methanolic extract with a yield of 270 mg/g and further purified from preparative TLC fractions using semi-preparative RP-HPLC, affording 82 mg of >95% pure compound with a 68.3% recovery, suitable for subsequent biological assays. It inhibited Gram-positive and Gram-negative bacteria, with MICs of 62.5 µg/mL against Staphylococcus aureus, Bacillus subtilis, and Listeria monocytogenes; 125–250 µg/mL against Escherichia coli and Salmonella typhimurium; and 500 µg/mL against Pseudomonas aeruginosa. Thymoquinone reduced biofilm formation (>80% at 25–50 µg/mL; MBIC50 ≈ 5.4–11.6 µg/mL), exhibited antioxidant activity (DPPH IC50 = 52.3 ± 2. 1 µg/mL; ABTS IC50 = 41.6 ± 1.9 µg/mL), stabilized erythrocyte membranes (IC50 ≈ 14.8 µg/mL), and inhibited carbohydrate-hydrolyzing enzymes, with stronger inhibition of α-glucosidase (~92%) than α-amylase (~84%) at 128 µg/mL. Conclusions: Thymoquinone is a major bioactive constituent of N. sativa seeds, exhibiting consistent multi-target in vitro activity. These findings highlight its functional relevance and in vivo investigations to establish therapeutic potential. Full article
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19 pages, 3110 KB  
Article
Efficient Removal of Oxytetracycline by Fe/N Co-Doped Biochar Derived from Fava Bean Straw: Performance and Mechanisms
by Xinyu Dong, Yu Zhang, Xinyi Zhang, Yaping Xu, Haitao Zhao, Nan Jiang, Lijun Meng and Shengyang Zheng
Separations 2026, 13(3), 96; https://doi.org/10.3390/separations13030096 - 18 Mar 2026
Abstract
To efficiently remove oxytetracycline (OTC) pollution from water bodies, this study utilized fava bean straw as a precursor to synthesize iron-nitrogen (Fe/N) co-doped biochar via pyrolysis. By regulating the synthesis ratio of iron and nitrogen, the material’s adsorption performance was optimized. The adsorption [...] Read more.
To efficiently remove oxytetracycline (OTC) pollution from water bodies, this study utilized fava bean straw as a precursor to synthesize iron-nitrogen (Fe/N) co-doped biochar via pyrolysis. By regulating the synthesis ratio of iron and nitrogen, the material’s adsorption performance was optimized. The adsorption characteristics and mechanisms of OTC were systematically investigated. The findings reveal that when the proportion of iron to nitrogen is set at 1:3, the adsorption efficacy reaches its peak. Moreover, this material demonstrates outstanding reusability characteristics. The outcomes of kinetic fitting suggest that the adsorption procedure adheres to the pseudo-second-order kinetic model (R2 = 0.967), primarily characterized by chemisorption. The isothermal adsorption data better fit the Langmuir model (R2 = 0.9984), with a theoretically attainable upper-limit adsorption capacity reaching 666.13 mg/g. This signifies the occurrence of monolayer adsorption, while the adsorption procedure constitutes an endothermic reaction. Based on characterization and mechanistic analysis, it can be concluded that the adsorption mechanism of Fe1N3KBC on OTC mainly involves π-π stacking interactions and chelation reactions. The Fe/N co-doped biochar prepared in this present research features readily available raw materials and a simple preparation process, combining high adsorption efficiency with excellent stability. It provides a novel technical paradigm for developing environmentally friendly adsorbents to address antibiotic pollution in water bodies. Full article
(This article belongs to the Special Issue Adsorption/Degradation for Environmental Pollutants)
13 pages, 721 KB  
Article
Effects of Boric Acid and Chlorhexidine as Cavity Disinfectants on Microleakage and Microshear Bond Strength in Primary Teeth
by Erdem Palaz, Ayşegül Ölmez and Zeliha Hatipoğlu Palaz
Children 2026, 13(3), 417; https://doi.org/10.3390/children13030417 - 18 Mar 2026
Abstract
Background: Cavity disinfection is commonly performed in pediatric restorative dentistry to reduce residual bacterial contamination. Although boric acid has been proposed as a potential antimicrobial agent, its effect on marginal integrity and adhesive performance in primary teeth remains unclear. This study evaluated the [...] Read more.
Background: Cavity disinfection is commonly performed in pediatric restorative dentistry to reduce residual bacterial contamination. Although boric acid has been proposed as a potential antimicrobial agent, its effect on marginal integrity and adhesive performance in primary teeth remains unclear. This study evaluated the effects of 3% and 5% boric acid, compared with 2% chlorhexidine (CHX), on microleakage and microshear bond strength of composite restorations in primary teeth bonded with a two-step self-etch adhesive system. Methods: Seventy-two extracted primary second molars were allocated to four groups (n = 18) for microleakage assessment: control, 2% CHX, 3% boric acid, and 5% boric acid. Standardized Class V cavities were prepared, disinfectants were applied for 60 s, and restorations were completed using Clearfil SE Bond and resin composite. Microleakage at occlusal and gingival margins was evaluated using dye penetration. For microshear bond strength testing, 60 primary molars (n = 15 per group) were treated similarly, and shear force was applied to bonded composite microcylinders. Data were analyzed at the p < 0.05 significance level. Results: Both boric acid groups showed significantly higher occlusal and gingival microleakage than the control and CHX groups (p < 0.05). Gingival microleakage was greater than occlusal microleakage in the boric acid groups (p < 0.05). Microshear bond strength was significantly reduced in the boric acid groups compared with the control (p < 0.05), whereas CHX had no significant effect. Failure modes did not differ significantly. Conclusions: While 2% CHX did not adversely affect adhesive performance, 3% and 5% boric acid increased microleakage and reduced bond strength. Caution is advised when using boric acid with self-etch adhesive systems in primary teeth. Full article
(This article belongs to the Section Pediatric Dentistry & Oral Medicine)
25 pages, 5731 KB  
Article
Optimization of UHPC Mix Design Using Polyacrylonitrile Fibers and Coarse Aggregates for Cost Reduction
by Qinshi Hu, Changli Su, Jiupeng Zhang and Xiaokang Zhao
Buildings 2026, 16(6), 1200; https://doi.org/10.3390/buildings16061200 - 18 Mar 2026
Abstract
To reduce the production cost of ultra-high performance concrete (UHPC), this study incorporated polyacrylonitrile (PAN) fibers and coarse aggregates (CA) to develop a novel UHPC with both excellent performance and reduced cost. A two-stage mortar-concrete design approach was employed to optimize the UHPC [...] Read more.
To reduce the production cost of ultra-high performance concrete (UHPC), this study incorporated polyacrylonitrile (PAN) fibers and coarse aggregates (CA) to develop a novel UHPC with both excellent performance and reduced cost. A two-stage mortar-concrete design approach was employed to optimize the UHPC mix proportion. First, the mortar matrix was preliminarily optimized based on particle packing theory, and its strength development mechanism was analyzed. Subsequently, response surface methodology was applied to systematically investigate the effects of PAN fiber content, CA content, and superplasticizer (SP) dosage on the slump flow, compressive strength, flexural strength, indirect tensile strength, freeze–thaw resistance, and dynamic mechanical properties of UHPC. The entropy weight method was then adopted to determine the optimal mix proportion, followed by cost estimation. The results indicate that the optimal mortar matrix composition consists of 61.4% cement, 15% silica fume, and 23.6% fly ash, achieving a flow spread of 246 mm, a compressive strength of 117.2 MPa, and a flexural strength of 24.9 MPa. When the PAN fiber content, CA content, and SP dosage were 0.5%, 20%, and 3.8%, respectively, the prepared PAN-CA UHPC(PCUHPC) exhibited the best overall performance. Compared with conventional UHPC, the material cost was reduced by 81.7%, and the compressive strength-normalized cost decreased by 75.4%. The UHPC developed in this study, characterized by outstanding performance and significant cost advantages, provides a feasible solution and theoretical support for broader engineering applications. Full article
(This article belongs to the Special Issue Advanced Structural Performance of Concrete Structures)
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18 pages, 4154 KB  
Article
Effect of CuO on the Structural, Antimicrobial, and Redox Activity of TiO2/TeO2/CuO Sol–Gel Powders
by Kalina Ivanova, Elitsa Pavlova, Iva Kirova, Iliana A. Ivanova and Albena Bachvarova-Nedelcheva
Gels 2026, 12(3), 253; https://doi.org/10.3390/gels12030253 - 18 Mar 2026
Abstract
This study investigates the synthesis, characterization, antimicrobial performance, and redox activity of sol–gel–derived TiO2/TeO2/CuO powders. The as-prepared gel with the nominal composition 80TiO2/10TeO2/10CuO was subjected to thermal treatment at 400 °C and 600 °C for [...] Read more.
This study investigates the synthesis, characterization, antimicrobial performance, and redox activity of sol–gel–derived TiO2/TeO2/CuO powders. The as-prepared gel with the nominal composition 80TiO2/10TeO2/10CuO was subjected to thermal treatment at 400 °C and 600 °C for 2 h, resulting in the formation of composite materials at both temperatures. By UV-Vis spectroscopy, it has been found that CuO is responsible for the red shifting of the absorption edge. The SEM-EDS analysis verified the elemental composition of the synthesized powders. The antimicrobial activity of the heat-treated powders was proved against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, representative Gram-negative and Gram-positive bacteria frequently associated with hospital-acquired infections and antibiotic resistance. At physiological pH, the 600 °C-treated sample exhibited strong prooxidant properties, supporting antimicrobial activity. At alkaline conditions, the nanomaterials were effective against superoxide radicals. The variation in oxidation with changes in pH is indicative of the potential for controlled application. Antimicrobial activity was assessed through minimum inhibitory concentration (MIC) assays and spot and luminescent tests, providing both quantitative and qualitative evaluations. Full article
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35 pages, 2351 KB  
Article
A Bilevel Optimization Model Based on Agency Theory in Relief Supply Chain Considering Authorization
by Xiaoli Wu and Xiulan Wang
Symmetry 2026, 18(3), 524; https://doi.org/10.3390/sym18030524 - 18 Mar 2026
Abstract
As a proactive response, reserving a certain amount of relief materials in advance is crucial for responding to potential disasters. Different from public tendering and bidding, this study proposes the purchasing mode of authorization, under which a nonprofit organization (NPO), as a buyer, [...] Read more.
As a proactive response, reserving a certain amount of relief materials in advance is crucial for responding to potential disasters. Different from public tendering and bidding, this study proposes the purchasing mode of authorization, under which a nonprofit organization (NPO), as a buyer, wholly authorizes the procurement of relief materials to a professional agent. The relief material procurement system under the purchasing mode of authorization is regarded as a bilevel relief supply chain consisting of one buyer, one agent, and two suppliers with private information about the quality levels of relief materials. For the disclosure of private information, the quality-related procurement strategy is designed in the form of a menu based on the suppliers’ private information. A bilevel optimization model is developed based on agency theory to derive the optimal strategic decisions, and the impacts of the main influencing factors on the optimal procurement strategy and the buyer’s minimum expected cost are discussed via numerical analysis. Then, the study is extended by exploring supplier’s alternative cost functions and supply availability, as well as proposing future research directions. This paper presents an optimal quality-related procurement strategy, which provides rules for quickly responding to the changes in influencing factors during the material procurement process, as well as the minimum expected cost for the buyer to purchase relief materials, which serves as a threshold for screening a reliable retail enterprise as the agent. Finally, three managerial implications with practical significance, drawn from our findings, are presented to facilitate cooperation between NPO and large retail enterprises in order to achieve effective procurement of relief materials at the pre-disaster preparation stage. Full article
(This article belongs to the Section Mathematics)
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17 pages, 1261 KB  
Systematic Review
Investigating Tourists’ Emergency Healthcare Access Barriers: A Systematic Literature Review
by Panagiota Peleka, Dimitra-Maria Aggelopoulou and Olga Siskou
Healthcare 2026, 14(6), 761; https://doi.org/10.3390/healthcare14060761 - 18 Mar 2026
Abstract
Background: Tourists often travel within their own country or abroad for business, leisure or to receive planned healthcare. However, they are often not prepared for unexpected medical emergencies that occur far from home. Seeking emergency healthcare during travel may pose various barriers and [...] Read more.
Background: Tourists often travel within their own country or abroad for business, leisure or to receive planned healthcare. However, they are often not prepared for unexpected medical emergencies that occur far from home. Seeking emergency healthcare during travel may pose various barriers and challenges to tourists. Aims: This systematic review aimed to identify the challenges and barriers tourists face while seeking emergency healthcare during travel. Methods: A comprehensive search was performed in PubMed, Scopus, Web of Science and ScienceDirect from 1st January 1995 to 31 October 2025. The review included studies focusing on tourists who sought emergency healthcare abroad. Due to the methodological heterogeneity of the studies making meta-analysis impossible, a narrative synthesis of the results was conducted. The review protocol was registered with PROSPERO (ID CRD420251156975). Results: From 608 initial titles (603 from database searches and 5 additional from similar articles), 10 studies were selected—5 cross-sectional and 5 retrospective. Most (7/10) were conducted in Asian countries, while others were conducted in Europe (1), the U.S.A. (1) and multiple countries (1). The participant number ranged from 37 to 2333. All studies included both genders, apart from one that focused exclusively on pregnant women. The most common challenges identified were language and cultural barriers, limited access to healthcare services in terms of appropriateness and timeliness of care and financial and insurance coverage issues. Conclusions: The findings underscore that tourists face multiple barriers when seeking emergency healthcare abroad, resulting in negative tourist travel experiences. Once identified, specific strategies should be adopted to improve accessibility and the overall quality of care for tourists. Full article
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38 pages, 1261 KB  
Review
Review of SMC and FOSMC Strategies for Rotary Wing UAVs
by Burcu Yaşkıran, Muhammet Öztürk and Barış Gökçe
Fractal Fract. 2026, 10(3), 200; https://doi.org/10.3390/fractalfract10030200 - 18 Mar 2026
Abstract
Unmanned Aerial Vehicles (UAVs) are widely used in fields such as autonomous missions, reconnaissance, surveillance, and various industrial applications. These vehicles can perform desired tasks without human intervention in challenging environmental conditions. However, UAV control can be difficult due to environmental factors, wind [...] Read more.
Unmanned Aerial Vehicles (UAVs) are widely used in fields such as autonomous missions, reconnaissance, surveillance, and various industrial applications. These vehicles can perform desired tasks without human intervention in challenging environmental conditions. However, UAV control can be difficult due to environmental factors, wind disturbances, and uncertainties in system parameters. Therefore, developing reliable control strategies for UAVs is a significant challenge for researchers and engineers. This study presents a comprehensive review of rotary-wing UAVs, focusing on quadcopter and helicopter systems. Approximately 77 studies were selected from the Web of Science (WOS) database and analyzed, with an emphasis on Sliding Mode Control (SMC) and Fractional-Order SMC (FOSMC) applications in these systems. The review addresses key topics such as degrees of freedom, proposed control methods, adjustment techniques, comparative methods, fractional-order definitions, simulation tools, and explanations. The literature analysis highlights current research trends by showing the performance advantages and limitations of SMC and FOSMC methods. Furthermore, future research directions and existing knowledge gaps are discussed in detail. This review was prepared to provide the control engineering community with a comprehensive understanding of SMC and FOSMC applications in rotary wing systems and to contribute to the development of innovative and effective control strategies. Full article
(This article belongs to the Section Engineering)
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Article
A Context-Adapted Living Wall Model for South Africa: A Quantity Surveying Perspective
by Rolien Terblanche, Samuel Johan De Witt and Aiden Graham Pringle
Sustainability 2026, 18(6), 2978; https://doi.org/10.3390/su18062978 - 18 Mar 2026
Abstract
Living Wall Systems (LWS) are vertical vegetated building façade systems that offer environmental and social benefits; however, their adoption in South Africa, particularly within the Western Cape (WC), remains limited due to high capital and maintenance costs and the absence of regionally adapted [...] Read more.
Living Wall Systems (LWS) are vertical vegetated building façade systems that offer environmental and social benefits; however, their adoption in South Africa, particularly within the Western Cape (WC), remains limited due to high capital and maintenance costs and the absence of regionally adapted design and cost models. This study investigates the viability and design development of LWS in the WC from a Quantity Surveying (QS) perspective, with the aim of developing a context-specific system utilising indigenous plant species and assessing its economic feasibility over the building life cycle. This study employed a mixed method research approach comprising a literature review, semi-structured interviews with industry professionals, thematic analysis, cost modelling, and the preparation of a detailed Bill of Quantities (BOQ). Life cycle costing (LCC) techniques were applied to evaluate long-term cost implications. The study resulted in the development of a criteria-led, context-adapted LWS model, termed Viridis 5045, which satisfies environmental, technical, and contextual requirements for the WC. The BOQ and LCC analyses provide projected capital and operational cost benchmarks for the proposed system. This study demonstrates that the Viridis 5045 model is technically feasible and contextually appropriate for application within the WC, supporting its consideration in sustainable construction practice when evaluated beyond conventional life cycle financial indicators. Future research should focus on the monetisation of long-term benefits, greywater integration, and Whole Life Costing. Full article
(This article belongs to the Section Green Building)
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