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13 pages, 5789 KB

Open AccessArticle

Porcine FRZB (sFRP3) Negatively Regulates Myogenesis via the Wnt Signaling Pathway

by Jingru Nie, Yu Fu, Xin Hao, Dawei Yan, Bo Zhang and Hao Zhang

Animals 2026, 16(2), 276; https://doi.org/10.3390/ani16020276 (registering DOI) - 16 Jan 2026

Secreted frizzled-related protein 3 (sFRP3/FRZB) is a soluble Wnt antagonist with established roles in skeletal development, however, its specific function in myogenesis remains underexplored. This study investigated the regulatory role of FRZB in muscle development, hypothesizing that it contributes to breed-specific [...] Read more.

Secreted frizzled-related protein 3 (sFRP3/FRZB) is a soluble Wnt antagonist with established roles in skeletal development, however, its specific function in myogenesis remains underexplored. This study investigated the regulatory role of FRZB in muscle development, hypothesizing that it contributes to breed-specific growth differences in pigs. We examined FRZB expression in fetal tissues of slow-growing (Tibetan and Wujin) and fast-growing (Large White) pigs, and assessed its function in C2C12 myoblasts via siRNA-mediated knockdown. FRZB was widely expressed across porcine fetal tissues, with significantly higher abundance in the longissimus dorsi of slow-growing breeds. In vitro, FRZB silencing significantly enhanced myoblast proliferation and migration. Furthermore, knockdown accelerated differentiation and promoted the formation of longer, thicker multinucleated myotubes, accompanied by the upregulation of myogenic (MyoD, MyoG, MyHC) and fusion (β1-integrin, Myomaker) markers. Transcriptional profiling revealed a shift toward hypertrophy (Fst and Nog upregulation) and away from atrophy (Atrogin1 downregulation). These findings identify FRZB as a negative regulator of myogenesis via the Wnt signaling pathway. The elevated expression in indigenous breeds suggests FRZB may impose a molecular constraint on muscle development, highlighting its potential as a candidate gene for regulating carcass traits. Full article

(This article belongs to the Section Pigs)

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12 pages, 1451 KB

Open AccessArticle

Growth Variation Among Thai Duckweed Species Under Axenic Conditions

by Siwaporn Jansantia, Yosapol Harnvanichvech, Athita Senayai, Nuttha Sanevas, Tokitaka Oyama and Ekaphan Kraichak

Biology 2026, 15(2), 159; https://doi.org/10.3390/biology15020159 (registering DOI) - 16 Jan 2026

Abstract

Duckweed has attracted considerable attention for its high protein content, rapid growth, and broad potential in biotechnological applications. Understanding key phenotypic traits is crucial for unlocking and maximizing this potential. While most studies on duckweed growth have been conducted under natural or non-sterile [...] Read more.

Duckweed has attracted considerable attention for its high protein content, rapid growth, and broad potential in biotechnological applications. Understanding key phenotypic traits is crucial for unlocking and maximizing this potential. While most studies on duckweed growth have been conducted under natural or non-sterile conditions, here we minimize environmental influences and focus on the genetic component of growth by assessing growth performance under axenic culture. In this study, we measured relative growth rate (RGR) in four duckweed species, Landoltia punctata (G. Mey.) Les & D. J. Crawford, Lemna aequinoctialis Welw., Spirodela polyrhiza (L.) Schleid., and Wolffia globosa (Roxb.) Hartog & Plas. collected from various natural locations across Thailand. A total of six to seven strains were tested for each species. The relative growth rates of studied species ranged from 0.012 day⁻¹ in S. polyrhiza to 0.162 day⁻¹ in W. globosa. Significant intraspecific variation was observed in L. punctata, S. polyrhiza, and W. globosa, with the coefficients of variation between 9.6 to 109.9 percent. Each strain showed distinct growth characteristics: Most displayed a steady growth pattern, whereas W. globosa showed exponential growth at Day 35 after the start of experiment. The results provide the first systematic comparisons of baseline growth rate data for duckweed species in Thailand. These findings advance the understanding of strain-specific growth traits in duckweed and establish a standardized protocol for evaluating growth traits under axenic conditions, providing a basis for future research and applications. Full article

(This article belongs to the Section Ecology)

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17 pages, 2257 KB

Open AccessArticle

The Effect of Fuel Bed Edges on Fire Dynamics

by Luis Reis, Jorge Raposo, Hugo Raposo and André Rodrigues

Forests 2026, 17(1), 124; https://doi.org/10.3390/f17010124 (registering DOI) - 16 Jan 2026

Abstract

Wildfires are among the most frequent and destructive natural hazards in Europe, particularly in Portugal. They have severe impacts on forests, ecosystems, human health, and infrastructure, leading to substantial socio-economic losses due to firefighting efforts and post-fire recovery costs. Moreover, wildfires cause numerous [...] Read more.

Wildfires are among the most frequent and destructive natural hazards in Europe, particularly in Portugal. They have severe impacts on forests, ecosystems, human health, and infrastructure, leading to substantial socio-economic losses due to firefighting efforts and post-fire recovery costs. Moreover, wildfires cause numerous casualties each year, highlighting the need for a deeper understanding of fire behaviour to support effective firefighting strategies and ensure the safety of both responders and communities. This study examines the influence of wind flow velocity variation on fire behaviour, both in the presence and absence of an edge wall in the fuel bed, aiming to replicate the characteristics of real wildfire fronts at a laboratory scale. Experimental tests were conducted at the Combustion Laboratory of the University of Coimbra using a shrub mixture, composed of Ulex europaeus, Baccharis trimera, and Caralluma adscendens, representing one of the most common fine fuels in Portuguese forested landscapes. This research provides novel insights by experimentally analyzing the combined effect of wind velocity variation and fuel bed edge presence on fire behaviour, paving the way for future comparisons with numerical simulations and real wildfire fronts. As expected, increasing wind velocity and the presence of fuel bed edges resulted in higher values of rate of spread, fireline intensity, and fire intensity. Full article

(This article belongs to the Special Issue Forest Fire: Landscape Patterns, Risk Prediction and Fuels Management)

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48 pages, 31780 KB

Open AccessReview

High-Temperature Oxidation-Resistant Composite Coatings for Extreme Environments: Material Systems, Design Strategies, Preparation Technologies, Performance Characterizations, and Research Challenges

by Yan-Long Yang, Shu-Qi Wang, Yong-Chun Zou, Lei Wen, Lei Huang, Guo-Liang Chen, Jia-Qi Zhu, Zhi-Yun Ye, En-Yu Xie, Qing-Yuan Zhao, Ya-Ming Wang, Jia-Hu Ouyang and Yu Zhou

J. Compos. Sci. 2026, 10(1), 51; https://doi.org/10.3390/jcs10010051 (registering DOI) - 16 Jan 2026

Abstract

With the development of aerospace, energy and power, nuclear energy, and chemical industries, hot-end components of various key equipment are gradually facing more severe high-temperature challenges. The high-temperature oxidation failure of key thermal structural materials in hot-end components has become a critical bottleneck [...] Read more.

With the development of aerospace, energy and power, nuclear energy, and chemical industries, hot-end components of various key equipment are gradually facing more severe high-temperature challenges. The high-temperature oxidation failure of key thermal structural materials in hot-end components has become a critical bottleneck restricting their service life. Consequently, there is an urgent need for oxidation protection of these components. Oxidation-resistant composite coatings are widely recognized as one of the most effective approaches to mitigating high-temperature oxidation. This review initially outlines the characteristics and anti-oxidation mechanisms of various coating materials, followed by an in-depth examination of the impact of structural modifications such as multi-layer/gradient design, diffusion barriers, and self-healing structures on the anti-oxidation efficacy of coatings. Furthermore, it discusses the fundamental principles and key features of advanced coating fabrication techniques, as well as summarizes the methods for characterizing the performance of anti-oxidation composite coatings under real operating conditions. Lastly, the review analyzes the current limitations and challenges facing anti-oxidation coatings in practical applications and provides insights into future development prospects. Full article

(This article belongs to the Section Composites Applications)

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15 pages, 2747 KB

Open AccessReview

Methodological Approaches to Assess the Resilience of Farming Systems to Climate Change: Examples from Latin America

by Clara I. Nicholls, Ángel Salazar-Rojas, Luis Vázquez, Rene Montalba, Mónica Machado, Inés Gazzano, Alejandro Henao and Miguel A. Altieri

Land 2026, 15(1), 172; https://doi.org/10.3390/land15010172 (registering DOI) - 16 Jan 2026

Abstract

The erratic nature, increasing prevalence, and intensity of extreme meteorological phenomena are forcing researchers and farmers to urgently develop adaptation practices to enhance the resilience of agroecosystems to climate change. It is strategically crucial to identify farming systems that have successfully endured recent [...] Read more.

The erratic nature, increasing prevalence, and intensity of extreme meteorological phenomena are forcing researchers and farmers to urgently develop adaptation practices to enhance the resilience of agroecosystems to climate change. It is strategically crucial to identify farming systems that have successfully endured recent climatic disturbances and understand the agroecological attributes that enabled them to resist and/or recover from droughts and hurricanes. This paper describes a number of methodologies utilized by Latin American researchers to assess agroecosystem resilience by estimating the vulnerability and the response capacity of selected farming systems to cope with climatic threats. The methodologies utilize a set of socio-ecological indicators that can be easily evaluated in the field, allowing farmers to determine whether their farms can withstand a drought or a major storm and, based on this information, select agroecological practices able to enhance the resiliency of their farms in preparation for future events. The principles and practices of resilience identified on successful, climate-resistant farms can be shared with thousands of producers, facilitating the broader adoption and scaling up of agroecological adaptation strategies. Full article

(This article belongs to the Special Issue Sustainable Development of the Territory and Use of Natural and Cultural Resources to Improve the Quality of Life of Residents, 2nd Edition)

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19 pages, 3366 KB

Open AccessArticle

Observed Change in Precipitation and Extreme Precipitation Months in the High Mountain Regions of Bulgaria

by Nina Nikolova, Kalina Radeva, Simeon Matev and Martin Gera

Atmosphere 2026, 17(1), 93; https://doi.org/10.3390/atmos17010093 (registering DOI) - 16 Jan 2026

Abstract

Precipitation in high mountain areas is of critical importance as these regions are major sources of freshwater, supporting river basins, ecosystems, and downstream communities. Changes in precipitation regimes in these regions can have cascading impacts on water availability, agriculture, hydropower, and biodiversity. The [...] Read more.

Precipitation in high mountain areas is of critical importance as these regions are major sources of freshwater, supporting river basins, ecosystems, and downstream communities. Changes in precipitation regimes in these regions can have cascading impacts on water availability, agriculture, hydropower, and biodiversity. The present study aims to give new information about precipitation variability in high mountain regions of Bulgaria (Musala, Botev Peak, and Cherni Vrah) and to assess the role of large-scale atmospheric circulation patterns for the occurrence of extreme precipitation months. The study period is 1937–2024, and the classification of extreme precipitation months is based on the 10th and 90th percentiles of precipitation distribution. The temporal distribution of extreme precipitation months was analyzed by comparison of two periods (1937–1980 and 1981–2024). The impact of atmospheric circulation was evaluated by correlation between the number of extreme precipitation months and indices for the North Atlantic Oscillation (NAO) and Western Mediterranean Oscillation (WeMO). Results show a statistically significant decrease in winter and spring precipitation at Musala and Cherni Vrah, and a persistent drying tendency at Cherni Vrah across all seasons. The frequency of extremely wet months in winter and autumn has sharply declined since 1981, whereas extremely dry months have become more common, particularly during the cold season. Precipitation erosivity also exhibits station-specific responses, with Musala and Cherni Vrah showing reduced monthly concentration, while Botev Peak retains pronounced warm-season erosive rainfall. Circulation analysis indicates that positive NAOI phases favor dry extremes, while positive WeMOI phases enhance wet extremes. These findings reveal a shift toward drier and more seasonally uneven conditions in Bulgaria’s alpine zone, increasing hydrological risks related to drought, water scarcity, and soil erosion. The identified shifts in precipitation seasonality and intensity offer essential guidance for forecasting hydrological risks and mitigating soil erosion in vulnerable mountain ecosystems. The study underscores the need for adaptive water-resource strategies and enhanced monitoring in high-mountain areas. Full article

(This article belongs to the Special Issue Air Temperature and Precipitation and Relationship to Atmospheric Circulation (2nd Edition))

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21 pages, 5725 KB

Open AccessArticle

The Synergistic Effects of rhArg with Bcl-2 Inhibitors or Metformin Co-Treatment in Multiple Cancer Cell Models

by Lai-Pan Sze, Vicky Mei-Ki Ho, Wing-Ki Fung, Kin-Ho Law, Yifan Tu, Yik-Hing So, Sai-Fung Chung, Wing-Leung Wong, Zhen Liu, Alisa Sau-Wun Shum, Leo Man-Yuen Lee and Yun-Chung Leung

Cells 2026, 15(2), 164; https://doi.org/10.3390/cells15020164 (registering DOI) - 16 Jan 2026

Abstract

Background: Recombinant human arginase (rhArg) has been proven to exhibit an anticancer effect via arginine starvation. To further improve the efficacy of rhArg, we examined the feasibility of a combination strategy with Bcl-2 inhibitors (ABT263 and ABT199) or an antidiabetic drug (metformin) and [...] Read more.

Background: Recombinant human arginase (rhArg) has been proven to exhibit an anticancer effect via arginine starvation. To further improve the efficacy of rhArg, we examined the feasibility of a combination strategy with Bcl-2 inhibitors (ABT263 and ABT199) or an antidiabetic drug (metformin) and investigated the mechanistic basis for these strategies. Methods: The combination effects were evaluated in a panel of human cancer cell lines modeling pancreatic ductal carcinoma (PDAC), triple-negative breast cancer (TNBC), colorectal cancer (CRC) and glioblastoma (GBM). Western blot analysis was used to evaluate the expression of apoptotic and cell cycle markers. MTT assay was used to evaluate the combination efficacy. Flow cytometric assays were used to investigate the apoptotic and cell cycle effects. Results: The combination of rhArg with sublethal doses of ABT263 significantly induced dose-dependent apoptosis, with elevated expression of apoptotic markers and a CI of 0.47 in U251. The combination inhibited CDK2 and cyclin A expression, indicating that the observed synergy also resulted from cell cycle arrest. We also found that rhArg + metformin was synergistic in a time-dependent manner. Compared to other amino acid depletion agents, rhArg + ABT263 was the most favorable combination pair. Conclusions: The combination of rhArg and ABT263 enhanced apoptosis and cell cycle arrest, demonstrating a potential broad-spectrum antitumor strategy. Full article

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12 pages, 518 KB

Open AccessArticle

Animal-Assisted Psychoeducational Intervention in Paediatric Oncohaematology: Evidence from a Single-Centre Observational Study

by Chiara Battaglini, Valentina Isaja, Gaia Riscossa, Mario Giordano, Paola Quarello, Giulia Zucchetti and Franca Fagioli

Children 2026, 13(1), 136; https://doi.org/10.3390/children13010136 (registering DOI) - 16 Jan 2026

Abstract

Background: Hospitalisation for paediatric oncohaematological diseases entails significant physical and psychological stress, often compromising children’s emotional regulation and daily functioning. In this context, complementary interventions can provide additional support to the clinical work conducted with children and adolescents undergoing treatment, fostering emotional [...] Read more.

Background: Hospitalisation for paediatric oncohaematological diseases entails significant physical and psychological stress, often compromising children’s emotional regulation and daily functioning. In this context, complementary interventions can provide additional support to the clinical work conducted with children and adolescents undergoing treatment, fostering emotional awareness and well-being. This study evaluates the feasibility and perceived benefits of an animal-assisted psychoeducational intervention to enhance emotional coping during hospitalisation. Methods: A single-centre observational study was conducted at Regina Margherita Children’s Hospital in Italy in collaboration with the ZOOM Foundation (Turin, Italy), between September 2023 and May 2025. Sixty patients aged 6–15 years participated in an intervention combining observation of an in-ward aquarium, virtual animal encounters, and completion of a psychoeducational booklet promoting emotional reflection through symbolic identification with animal behaviours. Results: The intervention showed high feasibility and acceptability: 90% of participants (54/60) reported positive emotions and enjoyment, 80% (48/60) found the booklet engaging, and all participants (100%) perceived care and attention from facilitators. The activities fostered engagement, curiosity, and well-being, though their impact on deeper emotional processing appeared limited. Conclusions: Animal-assisted psychoeducational interventions are feasible and well-received in paediatric oncohaematology, offering complementary support to clinical care by promoting emotional resilience and enriching the hospital experience. Full article

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39 pages, 8699 KB

Open AccessArticle

Numerical Reservoir Simulation of CO₂ Storage in Saline Aquifers: Assessment of Trapping Mechanisms, Geochemistry, O₂ Impurities and Brine Salinity

by Mazen Hamed and Ezeddin Shirif

Processes 2026, 14(2), 316; https://doi.org/10.3390/pr14020316 (registering DOI) - 16 Jan 2026

Abstract

It is a challenge in experimental studies today to accurately predict the trapping mechanisms in saline aquifers that influence the long-term CO₂ storage capacities. The inability in current experimental studies to quantify the effects of combined processes of solubility, hysteresis, and mineralization [...] Read more.

It is a challenge in experimental studies today to accurately predict the trapping mechanisms in saline aquifers that influence the long-term CO₂ storage capacities. The inability in current experimental studies to quantify the effects of combined processes of solubility, hysteresis, and mineralization as a means of affecting saline aquifer properties that influence CO₂ trapping mechanisms makes this topic interesting. A systematic framework in CMG-GEM compositional simulation studies is proposed in this article to assess the effects of gradually modelled trapping mechanisms on CO₂ storage performance. Simulation studies are conducted under identical constraints, trapping mechanisms, as well as operational factors in a sequential process that activates (i) solubility, (ii) solubility + hysteresis, and (iii) solubility + hysteresis + mineralization. The findings demonstrate distinct differences in trapping process behaviors as well as simulation stability under various modes: hysteresis effects largely improve immobile reserves as well as decrease plume migration, and, on the other hand, mineralization adds long-term dynamics of capacity increase as well as porosity-permeability alterations, especially in carbonate reservoirs. Through long-term post-injection simulations (up to 1000 years), the findings demonstrate that various trapping processes trigger over distinct time periods—years for immobile reserves, decades for dissolution, and centuries in the case of mineralization. This contribution is able to point out the computational efficiency as well as defective model behavior of concern to various physics levels, providing a practical guide to modelers in making a well-informed decision on what constitutes a minimum set of physics in long-term trustworthy CO₂ storage. Full article

(This article belongs to the Special Issue Innovations in Carbon Capture and Storage/Utilization (CCS-CCU): Sustainable Engineering and Biotechnological Perspectives)

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27 pages, 1112 KB

Open AccessArticle

SleepMFormer: An Efficient Attention Framework with Contrastive Learning for Single-Channel EEG Sleep Staging

by Mingjie Li, Jie Xia, Jiadong Pan, Sha Zhao, Xiaoying Zhang, Hao Jin and Shurong Dong

Brain Sci. 2026, 16(1), 95; https://doi.org/10.3390/brainsci16010095 (registering DOI) - 16 Jan 2026

Abstract

Background/Objectives: Sleep stage classification is crucial for assessing sleep quality and diagnosing related disorders. Electroencephalography (EEG) is currently recognized as a primary method for sleep stage classification. High-performance automatic sleep staging methods based on EEG leverage the powerful contextual modeling capabilities of Transformer [...] Read more.

Background/Objectives: Sleep stage classification is crucial for assessing sleep quality and diagnosing related disorders. Electroencephalography (EEG) is currently recognized as a primary method for sleep stage classification. High-performance automatic sleep staging methods based on EEG leverage the powerful contextual modeling capabilities of Transformer Encoder architectures. However, the global self-attention mechanism in Transformers incurs significant computational overhead, substantially hindering the training and inference efficiency of automatic sleep staging algorithms. Methods: To address these issues, we introduce an end-to-end framework for automatic sleep stage classification using single-channel EEG: SleepMFormer. At the algorithmic level, SleepMFormer adopts a task-driven simplification of the Transformer encoder to improve attention efficiency while preserving sequence modeling capability. At the training level, supervised contrastive learning is incorporated as an auxiliary strategy to enhance representation robustness. From an engineering perspective, these design choices enable efficient training and inference under resource-constrained settings. Results: When integrated with the SleePyCo backbone, the proposed framework achieves competitive performance on three widely used public datasets: Sleep-EDF, PhysioNet, and SHHS. Notably, SleepMFormer reduces training and inference time by up to 33% compared to conventional self-attention-based models. To further validate the generalizability of MaxFormer, we conduct additional experiments using DeepSleepNet and TinySleepNet as alternative feature extractors. Experimental results demonstrate that MaxFormer consistently maintains performance across different model architectures. Conclusions: Overall, SleepMFormer introduces an efficient and practical framework for automatic sleep staging, demonstrating strong potential for related clinical applications. Full article

(This article belongs to the Section Sleep and Circadian Neuroscience)

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Graphical abstract

27 pages, 11028 KB

Open AccessArticle

Integration of Satellite-Derived Meteorological Inputs into SWAT, XGBoost, WGAN, and Hybrid Modelling Frameworks for Climate Change-Driven Streamflow Simulation in a Data-Scarce Region

by Sefa Nur Yeşilyurt and Gülay Onuşluel Gül

Water 2026, 18(2), 239; https://doi.org/10.3390/w18020239 (registering DOI) - 16 Jan 2026

Abstract

The pressure of climate change on water resources has made the development of reliable hydrological models increasingly important, especially for data-scarce regions. However, due to the limited availability of ground-based observations, it considerably affects the accuracy of models developed using these inputs. This [...] Read more.

The pressure of climate change on water resources has made the development of reliable hydrological models increasingly important, especially for data-scarce regions. However, due to the limited availability of ground-based observations, it considerably affects the accuracy of models developed using these inputs. This also limits the ability to investigate future hydrological behavior. Satellite-based data sources have emerged as an alternative to address this challenge and have received significant attention. However, the transferability of these datasets across different model classes has not been widely explored. This paper evaluates the transferability of satellite-derived inputs to eleven types of models, including process-based (SWAT), data-driven methods (XGBoost and WGAN), and hybrid model structures that utilize SWAT outputs with AI models. SHAP has been applied to overcome the black-box limitations of AI models and gain insights into fundamental hydrometeorological processes. In addition, uncertainty analysis was performed for all models, enabling a more comprehensive evaluation of performance. The results indicate that hybrid models using SWAT combined with WGAN can achieve better predictive accuracy than the SWAT model based on ground observation. While the baseline SWAT model achieved satisfactory performance during the validation period (NSE ≈ 0.86, KGE ≈ 0.80), the hybrid SWAT + WGAN framework improved simulation skill, reaching NSE ≈ 0.90 and KGE ≈ 0.89 during validation. Models forced with satellite-derived meteorological inputs additionally performed as well as those forced using station-based observations, validating the feasibility of using satellite products as alternative data sources. The future hydrological status of the basin was assessed based on the best-performing hybrid model and CMIP6 climate projections, showing a clear drought signal in the flows and long-term reductions in average flows reaching up to 58%. Overall, the findings indicate that the proposed framework provides a consistent approach for data-scarce basins. Future applications may benefit from integrating spatio-temporal learning frameworks and ensemble-based uncertainty quantification to enhance robustness under changing climate conditions. Full article

(This article belongs to the Special Issue Application of Hydrological Modelling to Water Resources Management)

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19 pages, 6587 KB

Open AccessArticle

3D-Printed Cylindrical Dielectric Antenna Optimized Using Honey Bee Mating Optimization

by Burak Dokmetas

Electronics 2026, 15(2), 393; https://doi.org/10.3390/electronics15020393 (registering DOI) - 16 Jan 2026

Abstract

This study presents the design, optimization, and experimental validation of a dual-band dielectric monopole antenna. The proposed antenna structure consists of three concentric cylindrical dielectric layers, each with independently tunable permittivities and radii. This configuration allows the effective control of electromagnetic performance over [...] Read more.

This study presents the design, optimization, and experimental validation of a dual-band dielectric monopole antenna. The proposed antenna structure consists of three concentric cylindrical dielectric layers, each with independently tunable permittivities and radii. This configuration allows the effective control of electromagnetic performance over distinct frequency bands. To determine the optimal geometric and material parameters, the bio-inspired Honey Bee Mating Optimization (HBMO) algorithm is employed. The optimization process simultaneously maximizes antenna gain and minimizes reflection coefficient in the X and Ku bands. A cost function incorporating both gain and impedance matching criteria is formulated to achieve well-balanced solutions. The final antenna prototype was fabricated using a fused deposition modeling (FDM)-based 3D printer, where the dielectric properties of each layer are adjusted through variable infill rates. Simulated and measured results confirm stable dual-band operation with reflection coefficients below −10 dB, while the maximum in-band realized gains reach approximately 6.6 dBi in the X-band and 7.1 dBi in the Ku-band. These findings demonstrate the effectiveness of the proposed optimization approach and validate the feasibility of using 3D-printed dielectric-loaded structures as an efficient solution for high-frequency and space-constrained communication systems. Full article

(This article belongs to the Special Issue Antenna Design and Its Applications, 2nd Edition)

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19 pages, 6581 KB

Open AccessArticle

Data-Driven Design of HPDC Aluminum Alloys Using Machine Learning and Inverse Design

by Seunghyeok Choi, Sungjin Kim, Junho Lee, Jeonghoo Choi, MiYoung Lee, JaeHwang Kim, Jae-Gil Jung and Seok-Jae Lee

Metals 2026, 16(1), 99; https://doi.org/10.3390/met16010099 (registering DOI) - 16 Jan 2026

Abstract

This work proposes a data-driven design framework for high-pressure die-cast (HPDC) aluminum alloys that integrates robust data refinement, machine learning (ML) modeling, explainability, and inverse design. A total of 1237 tensile-test records from T5-aged HPDC alloys were aggregated into a curated dataset of [...] Read more.

This work proposes a data-driven design framework for high-pressure die-cast (HPDC) aluminum alloys that integrates robust data refinement, machine learning (ML) modeling, explainability, and inverse design. A total of 1237 tensile-test records from T5-aged HPDC alloys were aggregated into a curated dataset of 382 unique composition–heat-treatment combinations. Four regression models—Ridge regression, Random Forest (RF), XGBoost (XGB), and a multilayer perceptron (MLP)—were trained to predict yield strength (YS), ultimate tensile strength (UTS), and elongation (EL). Tree-based ensemble models (XGB and RF) achieved the highest accuracy and stability, capturing nonlinear interactions inherent to industrial HPDC data. In particular, the XGB model exhibited the best predictive performance, achieving test R² values of 0.819 for UTS and 0.936 for EL, with corresponding RMSE values of 15.23 MPa and 1.112%, respectively. Feature-importance and SHapley Additive exPlanations (SHAP) analyses identified Mn, Si, Mg, Zn, and T5 aging temperature as the most influential variables, consistent with metallurgical considerations such as microstructural stabilization and precipitation strengthening. Finally, RF-based inverse design suggested new composition–process candidates satisfying UTS > 300 MPa and EL > 8%, a region scarcely represented in the experimental dataset. These results illustrate how interpretable ML can expand the feasible design space of HPDC aluminum alloys and support composition–process optimization in industrial applications. Full article

(This article belongs to the Special Issue Solidification and Casting of Light Alloys)

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16 pages, 1710 KB

Open AccessArticle

Tracking Systemic and Ocular Vitamin A

by Diego Montenegro, Jin Zhao, Hyejin Kim, Sihua Cheng and Janet R. Sparrow

Cells 2026, 15(2), 163; https://doi.org/10.3390/cells15020163 (registering DOI) - 16 Jan 2026

Abstract

Vitamin A in the form of 11-cis-retinaldehyde is the chromophore essential to vision. Thus, deficiencies in vitamin A necessitate the implementation of vitamin A supplementation. Moreover, some vitamin A is lost from the visual cycle due to random reactions that generate [...] Read more.

Vitamin A in the form of 11-cis-retinaldehyde is the chromophore essential to vision. Thus, deficiencies in vitamin A necessitate the implementation of vitamin A supplementation. Moreover, some vitamin A is lost from the visual cycle due to random reactions that generate diretinaldehyde (bisretinoid) molecules; the latter are photoreactive and contribute to retinal disease. Here, we measured the systemic and ocular uptake of vitamin A along with bisretinoid as a function of vitamin A availability when supplied in the diet or by weekly i.p. injection in light- and dark-reared mice. Retinyl palmitate delivered as an i.p. bolus served to elevate plasma ROL but an associated increase in ocular 11-cisRAL was not observed in light- or dark-reared mice. In dark-reared mice, 11-cisRAL was more abundant when retinyl palmitate was provided in chow versus weekly i.p. injection; moreover, by the latter route, retinyl acetate was more effective. Conversely in dark-reared mice given retinyl palmitate by weekly i.p. injection versus chow, ocular atRAL was elevated. Liver atRE was elevated by increased retinyl palmitate in chow; the latter also favored elevated 11-cisRAL in dark-reared mice. In cyclic light-reared mice, ocular stores of atRE were increased by i.p. retinyl palmitate. With dark-rearing, there was no difference in bisretinoid (A2E) with retinyl palmitate in chow, nor by weekly i.p. injection; notably, bisretinoid levels were lower in cyclic light-reared mice due to photooxidative loss. In summary, light modulates the ocular retinoid, plasma atROL does not predict ocular levels of retinoid or bisretinoid and atRAL is elevated with sustained darkness. Full article

(This article belongs to the Special Issue Retinal Pigmented Epithelium (RPE) and the Choroid: Players and Partners for Vision)

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22 pages, 1188 KB

Open AccessArticle

Enhancing Maritime Safety Through Needs Analysis: Identifying Critical English Communication Skills for Pre-Service Maritime Students in a Chinese University

by Xingrong Guo, Mengyuan Zhen and Yiming Guo

Behav. Sci. 2026, 16(1), 130; https://doi.org/10.3390/bs16010130 (registering DOI) - 16 Jan 2026

Abstract

Effective communication in English is a critical behavioral competency for seafarers in a multilingual maritime environment, directly impacting operational safety. However, a gap exists between current Maritime English (ME) training in China and the actual communication demands of global seafaring. This study aims [...] Read more.

Effective communication in English is a critical behavioral competency for seafarers in a multilingual maritime environment, directly impacting operational safety. However, a gap exists between current Maritime English (ME) training in China and the actual communication demands of global seafaring. This study aims to identify the specific ME skills including linguistic, behavioral, and sociolinguistic dimensions that are most important for on-board performance and safety management from the perspective of pre-service maritime students at Shanghai Maritime University. A mixed-methods approach was used, combining structured questionnaires (n = 313) with in-depth follow-up interviews (n = 10). The results identified 24 highly needed ME skills, particularly focused on areas governing safety-critical behaviors, such as wireless communication, security protocols, and emergency procedures. In addition, based on learner profiling, the study depicts two different learner characteristics: exam-focused and work-focused students, each with different views on the importance of skills. Work-focused students place greater emphasis on the practicality of their skills. The interview data confirms and enriches these quantitative research results. The research findings emphasize that ME courses must be more closely aligned with real-world communicative scenarios and behaviors, prioritize scenario based teaching and practical operations, and tailor differentiated teaching based on learner psychology and behavioral preference. This study offers references for maritime education institutions with similar learner profiles to optimize ME curricula, prioritize secure communication skills, and strengthen industry-education collaboration, thereby enhancing pre-service maritime students’ safety behavior and professional competitiveness in China. Full article

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18 pages, 707 KB

Open AccessReview

Exploring Gender Differences in Adolescent Psychiatric Disorders: A Decade of Research

by Lidia Ricci, Pasquale Ricci, Angiola Avallone, Monica Calderaro, Giorgia Cafiero, Leonardo Iovino and Rosaria Ferrara

Healthcare 2026, 14(2), 225; https://doi.org/10.3390/healthcare14020225 (registering DOI) - 16 Jan 2026

Abstract

Background: Adolescence is a developmental phase characterised by profound biological, emotional and social changes and these changes make adolescents particularly vulnerable to the emergence of psychiatric disorders. In this context, gender differences in mental health disorders are of increasing clinical interest. Method: [...] Read more.

Background: Adolescence is a developmental phase characterised by profound biological, emotional and social changes and these changes make adolescents particularly vulnerable to the emergence of psychiatric disorders. In this context, gender differences in mental health disorders are of increasing clinical interest. Method: We conducted a scoping review of the literature regarding gender differences in psychiatric disorders during adolescence. Three databases, PubMed, Web of Science and EBSCO, were used to identify articles published in English from 2015 until 2025. Twenty-one studies fulfilled the inclusion criteria. Results: Ten studies deal with mood disorders, with a focus on gender differences in depression and anxiety during adolescence. Two articles analyse eating disorders, highlighting that girls show higher levels of food restriction and body dissatisfaction. Two studies focus on externalising and neurobehavioural disorders, showing a higher prevalence in boys than in girls. Four articles examine self-harm and suicidal behaviour, where girls report higher rates of suicidal ideation and self-harm. Finally, two studies address personality disorders in adolescence, noting a higher incidence of borderline traits and impulsive behaviour among girls. Conclusions: Research has revealed gender differences in the onset, frequency and factors associated with psychiatric disorders in adolescence. Understanding these differences is essential for developing prevention strategies, early diagnosis and specific interventions. Full article

(This article belongs to the Section Mental Health and Psychosocial Well-being)

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5 pages, 184 KB

Open AccessEditorial

Functional Nanomaterial-Based Gas Sensors and Humidity Sensors

by Zaihua Duan

Chemosensors 2026, 14(1), 25; https://doi.org/10.3390/chemosensors14010025 (registering DOI) - 16 Jan 2026

Abstract

Gas and humidity (water molecules) are important components of the environment and human respiration, which are closely related to human life and production [...] Full article

(This article belongs to the Special Issue Functional Nanomaterial-Based Gas Sensors and Humidity Sensors)

7 pages, 390 KB

Open AccessCommunication

Detection of Viable Nannizziopsis guarroi in Housing Environments Prior to Dermatological Lesion Development in Bearded Dragons (Pogona vitticeps)

by Jacob P. Dalen, Amanda D. Wong, Laura Adamovicz, Nicholas C. Liszka and Krista A. Keller

Animals 2026, 16(2), 275; https://doi.org/10.3390/ani16020275 (registering DOI) - 16 Jan 2026

Abstract

Nannizziopsis guarroi causes dermatomycosis in lizards and snakes. Little is known about the environment’s role in transmission of the fungus. The environments of bearded dragons experimentally inoculated with N. guarroi were cultured weekly to assess the presence of viable N. guarroi. Four [...] Read more.

Nannizziopsis guarroi causes dermatomycosis in lizards and snakes. Little is known about the environment’s role in transmission of the fungus. The environments of bearded dragons experimentally inoculated with N. guarroi were cultured weekly to assess the presence of viable N. guarroi. Four of six (4/6, 66.67%) enclosures demonstrated an environmental presence of N. guarroi prior to the observation of clinical lesions in the bearded dragon housed there. The environments were positive for N. guarroi growth 7–28 days prior to lesion development. The environment should be considered as a potential site of infection for naïve reptile hosts and environmental seeding may occur prior to the development of clinical nannizziomycosis in exposed lizards. Full article

(This article belongs to the Special Issue Advances in Reptile and Amphibian Infectious Diseases)

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12 pages, 313 KB

Open AccessArticle

In the Light of Healthcare Professionals: Beliefs About Chronic Low Back Pain

by Brigitta Péter, Adrian Georgescu, Ileana-Monica Popovici, Lucian Popescu, Timea Szabó-Csifó, Liliana-Elisabeta Radu and Pia-Simona Fagaras

Medicina 2026, 62(1), 183; https://doi.org/10.3390/medicina62010183 (registering DOI) - 16 Jan 2026

Abstract

Background and Objectives: Chronic low back pain (CLBP) is a prevalent condition that impairs quality of life, functionality, and work productivity. While most acute episodes of back pain resolve, 4–25% become chronic due to factors such as high pain intensity, psychological distress, and [...] Read more.

Background and Objectives: Chronic low back pain (CLBP) is a prevalent condition that impairs quality of life, functionality, and work productivity. While most acute episodes of back pain resolve, 4–25% become chronic due to factors such as high pain intensity, psychological distress, and maladaptive behaviors. Nonspecific CLBP is best understood through the biopsychosocial model, encompassing biological, psychological, and social influences, including kinesiophobia. Management relies on physical activity, pain education, and psychological interventions, with therapist knowledge and attitudes affecting outcomes. This study aimed to assess the prevalence of CLBP among healthcare workers, examine their knowledge of pain neurophysiology, evaluate kinesiophobia, and explore how personal experience with CLBP influences their beliefs, attitudes, and interactions with patients. Materials and Methods: A cross-sectional observational study was conducted from January to May 2025 among healthcare professionals. A total of 50 participants completed an online questionnaire, of which 42 were valid and included in the analysis. The questionnaire collected demographic and professional data, determined the presence of CLBP, and included three standardized instruments: the Revised Neurophysiology of Pain Questionnaire (rNPQ) to assess knowledge of pain mechanisms, the Health Care Providers’ Pain and Impairment Relationship Scale (HC-PAIRS) to evaluate beliefs about pain and disability, and the Tampa Scale of Kinesiophobia (TSK-11) to measure fear of movement. Data were analyzed using SPSS and Microsoft Excel. Results: Among the 42 participants, 11 demonstrated low, 28 moderate, and 3 high knowledge of pain neurophysiology (rNPQ), with a mean score of 5.66. On the HC-PAIRS, the majority (30 participants) scored above 60, indicating beliefs that pain leads to disability, while 12 scored below 60, reflecting a biopsychosocial perspective; gender did not significantly affect HC-PAIRS scores (p = 0.213). As for kinesiophobia (TSK-11), 24 participants had low, 17 moderate, and 1 clinically significant fear of movement. Correlation analysis revealed that younger participants had higher rNPQ scores (r = −0.358, p = 0.020) and lower TSK-11 scores (r = −0.389, p = 0.011). TSK-11 scores increased with age (r = 0.432, p = 0.004), while HC-PAIRS scores showed no significant correlations. Conclusions: Healthcare professionals, particularly physiotherapists, show gaps in knowledge of pain neurophysiology and a tendency toward biomedical beliefs regarding chronic low back pain. This cross-sectional study indicates that a greater understanding of pain mechanisms is associated with lower kinesiophobia, emphasizing the importance of education. Integrating the biopsychosocial model into undergraduate and continuing professional training, through interdisciplinary and practical modules, may improve knowledge, reduce maladaptive fear-avoidance behaviors, and enhance patient care. Future studies should include larger, more diverse samples and assess the long-term impact of educational interventions on clinical practice. Full article

(This article belongs to the Special Issue Physical Therapy: A New Perspective)

28 pages, 1252 KB

Open AccessReview

Reframing Dementia Prevention Strategies Aligned with the WHO Global Action Plan: A Structured Narrative Review Focusing on Mild Behavioral Impairment

by Efthalia Angelopoulou, Sokratis Papageorgiou and John Papatriantafyllou

Neurol. Int. 2026, 18(1), 18; https://doi.org/10.3390/neurolint18010018 (registering DOI) - 16 Jan 2026

Abstract

Background/Objectives: Dementia represents a growing public health challenge. The WHO Global Action Plan on the Public Health Response to Dementia emphasizes early detection, risk reduction, and innovation as key priorities. Mild Behavioral Impairment (MBI), defined as the emergence of persistent neuropsychiatric symptoms [...] Read more.

Background/Objectives: Dementia represents a growing public health challenge. The WHO Global Action Plan on the Public Health Response to Dementia emphasizes early detection, risk reduction, and innovation as key priorities. Mild Behavioral Impairment (MBI), defined as the emergence of persistent neuropsychiatric symptoms in older individuals, represents a potential marker of early neurodegeneration and possible window for early intervention. This review explores the role of MBI in dementia prevention, mapping current evidence within the WHO Global Action Plan framework. Methods: A comprehensive search was performed in PubMed, Scopus, and the official WHO website, during 1 September 2025–10 November 2025, without time restrictions. Eligible sources included original clinical studies, reviews, and policy documents addressing MBI, dementia prevention, and public health. Data were thematically synthesized according to the seven objectives of WHO: (1) dementia as a public health priority, (2) dementia awareness and friendliness, (3) dementia risk reduction, (4) dementia diagnosis, treatment, care and support, (5) support for dementia carers, (6) information systems for dementia, and (7) dementia research and innovation. Results: Accumulating evidence indicates that MBI assessment can capture early behavioral manifestations of neurodegenerative and other forms of dementia, correlating with fluid, neuroimaging and genetic biomarkers. Integrating MBI screening through the easy-to-administer MBI Checklist (MBI-C) into clinical and community-based care, including telemedicine pathways and research, may enhance early identification and personalized interventions, enrich the pool for clinical trials, and facilitate research in biomarker and therapy. MBI-related research further supports its integration in remote digital monitoring and population-based prevention. Conclusions: Embedding MBI-informed screening and interventions into national dementia strategies aligns with WHO objectives for early, equitable and scalable prevention and brain health. Full article

(This article belongs to the Section Aging Neuroscience)

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15 pages, 1657 KB

Open AccessReview

Recent Advances in Research on Iron Metabolism, Ferritin, and Hepcidin

by Alessandro Polizzi

Int. J. Mol. Sci. 2026, 27(2), 906; https://doi.org/10.3390/ijms27020906 (registering DOI) - 16 Jan 2026

Abstract

This study aimed to provide a synthesis of current knowledge on iron homeostasis, focusing on major metabolic pathways and evolving research perspectives. A systematic review was conducted, analyzing the most relevant pathological conditions associated with iron metabolism, including iron overload and iron deficiency. [...] Read more.

This study aimed to provide a synthesis of current knowledge on iron homeostasis, focusing on major metabolic pathways and evolving research perspectives. A systematic review was conducted, analyzing the most relevant pathological conditions associated with iron metabolism, including iron overload and iron deficiency. Iron overload (IO) encompasses a wide range of disorders that lead to systemic iron accumulation and organ damage, while iron deficiency (ID) is characterized by insufficient iron availability for physiological needs. IO is dealt with a focused attention, exploring molecular mechanisms and emerging therapeutic strategies. In this context, hepcidin not only represents a valuable biomarker for iron overload but also serves as a potential target for novel therapies that are currently in the experimental phase. Conversely, for ID, both traditional biomarkers and recently proposed indicators help in diagnosing ID and correlating it with erythropoietic activity. Full article

(This article belongs to the Special Issue Recent Advances in Iron Metabolism, Ferritin and Hepcidin Research: 3rd Edition)

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10 pages, 1223 KB

Open AccessBrief Report

On the Chronology of the Petralona Hominid

by Ioannis Liritzis

Quaternary 2026, 9(1), 7; https://doi.org/10.3390/quat9010007 (registering DOI) - 16 Jan 2026

Abstract

The chronology of the Petralona hominid remains a key issue in European Middle Pleistocene paleoanthropology. The recent study by Falguères et al., which reports new U-series ages of approximately 300 ka for travertines associated with the Petralona cranium, provides an important opportunity to [...] Read more.

The chronology of the Petralona hominid remains a key issue in European Middle Pleistocene paleoanthropology. The recent study by Falguères et al., which reports new U-series ages of approximately 300 ka for travertines associated with the Petralona cranium, provides an important opportunity to reassess this long-standing debate. This commentary critically evaluates the strengths and limitations of that contribution, with particular attention to the treatment of analytical precision, geological uncertainties, and stratigraphic constraints inherent to speleothem dating. While the new data represent a valuable analytical advance and independently support a Middle Pleistocene age, the reported narrow error margins warrant cautious interpretation. When broader sources of uncertainty are considered, the results are best viewed as a confirmation rather than a fundamental revision of the established chronological framework. Overall, this commentary situates the findings of the new study within their broader methodological and historical context and underscores their significance for refining, but not redefining, the age and evolutionary placement of the Petralona hominid. Full article

(This article belongs to the Collection Feature Papers in Quaternary Research)

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20 pages, 2354 KB

Open AccessArticle

Combined Effects of Vegetable Oil-, Micronutrient-, and Activated Flavonoid-Based Biostimulants on Photosynthesis, Nematode Suppression, and Fruit Quality of Cucumber (Cucumis sativus L.)

by Georgia Ouzounidou, Niki-Sophia Antaraki, Antonios Anagnostou, George Daskas and Ioannis-Dimosthenis Adamakis

Plants 2026, 15(2), 274; https://doi.org/10.3390/plants15020274 (registering DOI) - 16 Jan 2026

Abstract

The agricultural industry faces increasing environmental degradation due to the intensive use of conventional chemical fertilizers, leading to water pollution and alterations in soil composition. In addition, root-knot and cyst nematodes are major constraints to cucumber production, causing severe root damage and yield [...] Read more.

The agricultural industry faces increasing environmental degradation due to the intensive use of conventional chemical fertilizers, leading to water pollution and alterations in soil composition. In addition, root-knot and cyst nematodes are major constraints to cucumber production, causing severe root damage and yield losses worldwide, underscoring the need for sustainable alternatives to conventional fertilization and pest management. Under greenhouse conditions, a four-month cultivation trial evaluated vegetable oil-, micronutrient-, and activated flavonoid-based biostimulants, applying Key Eco Oil^® (Miami, USA) via soil drench (every 15 days) combined with foliar sprays of CropBioLife^® (Victoria, Australia) and KeyPlex 120^® (Miami, USA) (every 7 days). Results showed reduced parasitic nematodes by 66% in soil and decreased gall formation by 41% in roots. Chlorophyll fluorescence and infrared gas analysis revealed higher oxygen-evolving complex efficiency (38%), increased PSII electron transport, improved the fluorescence decrease ratio, also known as the vitality index (Rfd), and higher CO₂ assimilation compared to conventional treatments. Processed cucumbers showed higher sugar and nearly double ascorbic acid content, with improved flesh consistency and color. Therefore, the application of these bioactive products significantly reduced nematode infestation while enhancing plant growth and physiological performance, underscoring their potential as sustainable tools for crop cultivation and protection. These results provide evidence that sustainable bioactive biostimulants improve plant resilience, productivity, and nutritional quality, offering also an environmentally sound approach to pest management. Full article

(This article belongs to the Special Issue Plants 2025—from Seeds to Food Security)

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21 pages, 2749 KB

Open AccessArticle

Optimization of Microchannel Heat Sink with Concave Compound Triangular Prism

by Taiguan Song, Jingang Yang, Zhili Su, Maimaitijiang Bairna and Jiatong Zhang

Buildings 2026, 16(2), 376; https://doi.org/10.3390/buildings16020376 (registering DOI) - 16 Jan 2026

Abstract

To address the thermal management challenges of high-heat-flux electronic devices, this study investigates heat transfer enhancement in microchannels with composite cavity-rib triangular prism structures through numerical simulations. Three cavity configurations (arc-shaped, rectangular, and trapezoidal) with depths ranging from 0.2 to 0.35 mm were [...] Read more.

To address the thermal management challenges of high-heat-flux electronic devices, this study investigates heat transfer enhancement in microchannels with composite cavity-rib triangular prism structures through numerical simulations. Three cavity configurations (arc-shaped, rectangular, and trapezoidal) with depths ranging from 0.2 to 0.35 mm were analyzed. The results reveal that increasing the cavity depth elevated the friction resistance, with the trapezoidal cavities exhibiting the highest increase in friction resistance at Re > 550. The heat transfer performance exhibited a nonlinear improvement with depth: arc-shaped cavities (D = 0.35 mm) achieved maximum Nusselt numbers at low Reynolds numbers, whereas trapezoidal cavities excelled at high Reynolds numbers. The thermal-hydraulic performance evaluation criterion (PEC) identified the arc-shaped cavity (D = 0.35 mm) as optimal, achieving a maximum PEC value of 1.7495, which surpassed the rectangular and trapezoidal configurations by 4.3% and 0.7%, respectively. This study demonstrates that composite cavity-rib structures enhance secondary flow disturbances, providing critical insights for cross-scale parameter optimization in microchannel design. Full article

(This article belongs to the Special Issue Carbon-Neutral Pathways for Urban Building Design)

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16 pages, 3760 KB

Open AccessArticle

A DFT Study on Sc-Catalyzed Diastereoselective Cyclization of 2-Picoline with 1,5-Hexadiene: Mechanism and Origins of Regio- and Stereoselectivity

by Guangli Zhou, Shuangxin Zhai, Xia Leng, Yunzhi Li, Qiying Xia and Yi Luo

Inorganics 2026, 14(1), 28; https://doi.org/10.3390/inorganics14010028 (registering DOI) - 16 Jan 2026

Abstract

Density functional theory (DFT) calculations elucidate the mechanism of diastereoselective cyclization of 2-picoline with 1,5-hexadiene catalyzed by a cationic half-sandwich scandium complex. The catalytic cycle proceeds through four key stages: formation of active species, initial alkene insertion, cis-selective cyclization, and protonation. Central [...] Read more.

Density functional theory (DFT) calculations elucidate the mechanism of diastereoselective cyclization of 2-picoline with 1,5-hexadiene catalyzed by a cationic half-sandwich scandium complex. The catalytic cycle proceeds through four key stages: formation of active species, initial alkene insertion, cis-selective cyclization, and protonation. Central to the mechanism is the dual role of 2-picoline, which initially coordinates as a supporting ligand to facilitate C–H activation and regioselective 1,2-insertion but must dissociate to enable stereocontrol. The mono(2-picoline)-coordinated complex C3 is identified as the thermodynamically favored active species. C–H activation reactivity follows the trend: ortho-C(sp²)–H (2-picoline-free) > ortho-C(sp²)–H (2-picoline-coordinated) > benzylic C(sp³)–H (2-picoline-free) > benzylic C(sp³)–H (2-picoline-coordinated), a preference governed by a wider C_α–Sc–C_α′ angle and shorter Sc···X (X = C_α, C_α′, H) distances that enhance scandium–substrate interaction. Subsequent 1,5-hexadiene insertion proceeds with high 1,2-regioselectivity through a picoline-assisted pathway. The stereoselectivity-determining step reveals a mechanistic dichotomy: while picoline coordination is essential for initial activation, its dissociation is required for intramolecular cyclization. This ligand displacement avoids prohibitive steric repulsion in the transition state, directing the reaction exclusively toward the cis-cyclized product. The cycle concludes with a sterically accessible mono-coordinated protonation. This work establishes a “ligand-enabled then ligand-displaced” mechanism, highlighting dynamic substrate coordination as a critical design principle for achieving high selectivity in rare-earth-catalyzed C–H functionalization. Full article

(This article belongs to the Section Coordination Chemistry)

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14 pages, 1056 KB

Open AccessArticle

Kinetics of Lactic Acid, Acetic Acid and Ethanol Production During Submerged Cultivation of a Forest Litter-Based Biofertilizer

by Sophie Nafil, Lucie Miché, Loris Cagnacci, Martine Martinez and Pierre Christen

Fermentation 2026, 12(1), 52; https://doi.org/10.3390/fermentation12010052 (registering DOI) - 16 Jan 2026

Abstract

Fermented forest litter (FFL) is a biofertilizer obtained by anaerobic fermentation of forest litter combined with agricultural by-products. Its production involves an initial one-month solid-state fermentation of oak litter mixed with whey, molasses and wheat bran, followed by a one-week submerged fermentation-called the [...] Read more.

Fermented forest litter (FFL) is a biofertilizer obtained by anaerobic fermentation of forest litter combined with agricultural by-products. Its production involves an initial one-month solid-state fermentation of oak litter mixed with whey, molasses and wheat bran, followed by a one-week submerged fermentation-called the “activation” phase-during which the solid FFL is fermented with sugarcane molasses diluted in water. This study aimed to evaluate the effects storage duration (6, 18 and 30 months), and temperature (ambient and 29 °C) on the activation phase. For this purpose, pH, sugar consumption and metabolite production dynamics were monitored. Under all experimental conditions, the pH dropped to values close to 3.5, sucrose was rapidly hydrolyzed, and glucose was preferentially consumed over fructose. Fructose was metabolized only after glucose was depleted, suggesting the involvement of fructophilic microorganisms. The time-course evolution of lactic acid (LA) concentration was adequately fitted by the Gompertz model (R² > 0.970). The highest LA_max concentration (6.30 g/L) and production rate (2.16 g/L·d) were obtained with FFL stored for 6 months. Acetic acid (AA) and ethanol were also detected reaching maxima values of 1.19 g/L and 0.96 g/L, respectively. Their profiles varied depending on the experimental conditions. Notably, the AA/LA ratio increased with the age of the FFL. Overall, sugar consumption and metabolite production were significantly slower at ambient temperature, than at 29 °C. These results contribute to a better understanding of the metabolic dynamics during FFL activation and highlight key parameters that should be considered to optimize future biofertilizer production processes. Full article

(This article belongs to the Special Issue 10th Anniversary of Fermentation: Feature Papers in Section "Industrial Fermentation")

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