Search Results (128)

Background: Endolichenic fungi represent an emerging source of bioactive secondary metabolites; however, the genomic basis of their chemical diversity remains largely poorly characterized. Specifically, the metabolic capabilities of Cladosporium limoniforme have not been explored at the genomic level. Objectives: This study aimed to characterize the biosynthetic potential of C. limoniforme by presenting its first whole-genome sequence and conducting a comparative analysis of its biosynthetic gene clusters (BGCs), with a specific focus on the evolutionary conservation of the DHN-melanin pathway. Methods: Genome mining was performed using antiSMASH and fungiSMASH tools. Comparative genomics involved heatmap-based distribution analysis across the Cladosporium genus, synteny profiling using Clinker to assess gene order conservation, and Maximum Likelihood phylogenetic analysis of the polyketide synthase (T1PKS) domain. Results: We identified 26 putative BGCs, revealing a largely untapped metabolic repertoire. Comparative analysis demonstrated a high degree of conservation for the metachelin C (siderophore) and 1,3,6,8-tetrahydroxynaphthalene (T4HN) clusters across the genus. Notably, synteny and phylogenetic analyses showed that while C. limoniforme retains a conserved, ancestral T1PKS core essential for stress survival, it exhibits a significant reduction in accessory genes compared to plant-pathogenic congeners. Conclusions: These findings support a “metabolic streamlining” hypothesis driven by the endolichenic lifestyle, where the fungus retains essential protective machinery while shedding costly accessory genes unnecessary in the buffered lichen niche. This study establishes C. limoniforme as a valuable genomic resource for future biotechnological research. Full article

Allomelanin is a natural class of melanin found mainly in fungi and derived from nitrogen-free precursors such as 1,8-dihydroxynaphthalene (1,8-DHN). Despite its biological relevance, allomelanin remains significantly less explored than other synthetic melanin analogs, particularly compared to polydopamine, a synthetic analog of eumelanin. In this review, we provide a comprehensive overview of current knowledge on allomelanin, summarizing the main methods used to characterize its molecular structure, morphology, and chemical functionalities. We also present its emerging applications, ranging from human health to materials science, highlighting how its optical characteristics, ability to modulate redox processes, and antioxidant properties support its growing technological interest. Finally, we describe the natural presence and biological role of allomelanin, highlighting how knowledge of its biosynthetic processes and functions in nature can guide more effective strategies for the design and optimization of new allomelanin materials. Full article

District heating networks (DHNs) are a key technology in the transition toward sustainable heat supply, increasingly integrating renewable sources and thermal energy storage. High-temperature aquifer thermal energy storage (HT-ATES) can enhance DHN efficiency by shifting heat production over time, potentially reducing both costs and greenhouse gas emissions. However, most life cycle assessments (LCAs) remain static, rely on average data, and neglect temporal dispatch dynamics and marginal substitution among heat sources for environmental evaluation. This study introduces a dynamic life cycle inventory framework that explicitly links HT-ATES-operation scheduling in DHNs with marginal life cycle data. The framework expands system boundaries to capture time-varying changes in heat composition, combines a district heating merit-order representation (distinguishing must-run and flexible capacities) with linear programming to determine least-cost dispatch, and translates marginally displaced technologies into environmental and economic consequences. Foreground inputs are derived from an existing third-generation DHN (heat demand, generation assets, efficiencies) and publicly available energy carrier cost data and are linked to consequential background inventory datasets (ecoinvent). The framework is demonstrated for one year of operation for an HT-ATES concept with 50 GWh of injected heat. Hourly resolved results identify the marginally displaced technologies and indicate annual reductions of 5.86 kt CO₂e alongside cost savings of EUR 1.09 M. A comparison of alternative operation schedules shows strong sensitivity of both economic and environmental performance to operational strategy. Overall, the proposed framework provides a replicable and adaptable basis for consequential assessment of HT-ATES operation in DHNs and supports strategic decision-making on seasonal thermal storage deployment in low-carbon heat systems. Full article

The heating and cooling sector accounts for nearly half of Europe’s energy consumption and remains heavily dependent on fossil fuels, emphasizing the urgent need for decarbonization. Simultaneously, the global shift toward renewable energy is accelerating, alongside growing interest in decentralized energy systems where prosumers play a significant role. In this context, district heating and cooling networks, serving nearly 100 million people, are strategically important. In next-generation systems, thermal prosumers can feed-in locally produced or industrial waste heat into the network via bidirectional substations, allowing energy flows in both directions and enhancing system efficiency. The complexity of these networks, with numerous users and interacting heat flows, requires advanced predictive models to manage large volumes of data and multiple variables. This work presents the development of a predictive model based on artificial neural networks (ANNs) for forecasting excess thermal renewable energy from a bidirectional substation. The numerical model of a substation prototype designed by ENEA provided the physical data for the ANN training. Thirteen years of simulation results, combined with extensive meteorological data from ECMWF, were used to train and to test a multi-step ANN capable of forecasting the six-hour thermal power feed-in horizon using data from the preceding 24 h, improving operational planning and control strategies. The ANN model demonstrates high predictive capability and robustness in replicating thermal power dynamics. Accuracy remains high for horizons up to six hours, with MAE ranging from 279 W to 1196 W, RMSE from 662 W to 3096 W, and R² from 0.992 to 0.823. Overall, the ANN satisfactorily reproduces the behavior of the bidirectional substation even over extended forecasting horizons. Full article

While water content is a critical factor affecting the outcome of cryopreservation, the mechanism by which it influences seed viability after cryopreservation remains unclear. In this study, Paeonia lactiflora seeds with different water content as experimental materials, analyzed the seed viability, oxidative stress indicators, and transcriptomics before and after cryopreservation, to explore the mechanism of the seed viability changes. The results demonstrated that after cryopreservation, seeds with high water content displayed reduced viability, along with abnormal accumulation of reactive oxygen species (ROS) content, which subsequently triggered ROS-mediated oxidative damage. In contrast, seeds with low water exhibited enhanced following cryopreservation, their ROS levels remained relatively stable, while notable alterations were detected in multiple antioxidant system parameters. At the transcriptional level, 1224 differentially expressed genes (DEGs) up-regulated and 1839 DEGs were down-regulated in seeds with high water content after cryopreservation, but 2090 DEGs up-regulated and 1783 DEGs down-regulated in the seeds with low water content. Among them, 687 DEGs were common to both the high- and low-water content seed groups. Gene Ontology (GO) functional analysis indicated that these DEGs are primarily involved physiological metabolic processes including osmotic response, glucosidase activity, protein kinase binding, and response to hydrogen peroxide. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis confirmed that the Mitogen-Activated Protein Kinase (MAKP) plant signaling pathway and the starch and sucrose metabolism pathway are the key pathways governing the response of seeds with varying water contents to cryopreservation. Finally, through weighted gene co-expression network pinpointed DHN1 and LEA34 as the core genes regulating changes in seed viability after cryopreservation. These findings offer a broader perspective for in-depth exploration of the molecular regulatory mechanisms underlying the differences in seed viability changes after cryopreservation and are crucial for comprehensively clarifying the precise pathways via which these key genes regulate seed viability changes after cryopreservation. Full article

Strawberries are important cash crops. Traditional manual picking is costly and inefficient, while automated harvesting robots are hindered by field challenges like stem-leaf occlusion, fruit overlap, and appearance/maturity variations from lighting and viewing angles. To address the need for accurate cross-maturity fruit identification and keypoint detection, this study constructed a strawberry image dataset covering multiple varieties, ripening stages, and complex ridge-cultivation field conditions: MSRBerry. Based on the YOLO11-pose framework, we proposed DHN-YOLO with three key improvements: replacing the original C2PSA with the CDC module to enhance subtle feature capture and irregular shape adaptability; substituting C3K2 with C3H to strengthen multi-scale feature extraction and robustness to lighting-induced maturity/color variations; and upgrading the neck into a New-Neck via CA and dual-path fusion to reduce feature loss and improve critical region perception. These modifications enhanced feature quality while cutting parameters and accelerating inference. Experimental results showed DHN-YOLO achieved 87.3% precision, 88% recall, and 78.6% mAP@50:95 for strawberry detection (0.9%, 1.6%, 5% higher than YOLO11-pose), and 83%, 87.5%, 83.6% for keypoint detection (1.9%, 2.1%, 4.6% improvements). It also reached 71.6 FPS with 15 ms single-image inference. The overall performance of DHN-YOLO also surpasses other mainstream models such as YOLO13, YOLO10, DETR and so on. This demonstrates DHN-YOLO meets practical needs for robust strawberry and picking point detection in complex agricultural environments. Full article

Melanins are multifunctional biopolymers with unique properties, ranging from UV and radiation protection to antioxidant activity and metal chelation, making them highly attractive for biomedical applications. Despite extensive research, the mechanisms underlying melanin formation remain only partially understood, and access to these biopolymers therefore relies on suitable molecular precursors. While most studies have focused on catecholamine-derived eumelanins such as 3,4-dihydroxyphenylalanine (L-DOPA) and dihydroxyindole (DHI), nitrogen-free precursors such as 1,8-dihydroxynaphthalene (1,8-DHN) are emerging as promising routes to allomelanins. To date, however, these two precursor classes have largely been investigated separately, limiting a broader understanding of structure–function relationships. This review aims to compare electrochemical and redox-based pathways to catecholamine- and DHN-derived materials, emphasizing both their common principles and distinctive features. By bridging these parallel research streams, we propose a methodological framework for guiding future research on melanin-inspired materials and bioelectrochemical technologies. Full article

This work explores the integration of Proton Exchange Membrane (PEM) electrolysis waste heat with district heating networks (DHN), aiming to enhance the overall energy efficiency and economic viability of hydrogen production systems. PEM electrolysers generate substantial amounts of low-temperature waste heat during operation, which is often dissipated and left unutilised. By recovering such thermal energy and selling it to district heating systems, a synergistic energy pathway that supports both green hydrogen production and sustainable urban heating can be achieved. The study investigates how the electrolyser’s operating temperature, ranging between 50 and 80 °C, influences both hydrogen production and thermal energy availability, exploring trade-offs between electrical efficiency and heat recovery potential. Furthermore, the study evaluates the compatibility of the recovered heat with common heat emission systems such as radiators, fan coils, and radiant floors. Results indicate that valorising waste heat can enhance the overall system performance by reducing the electrolyser’s specific energy consumption and its levelized cost of hydrogen (LCOH) while supplying carbon-free thermal energy for the end users. This integrated approach contributes to the broader goal of sector coupling, offering a pathway toward more resilient, flexible, and resource-efficient energy systems. Full article

Due to the complexity of district heating systems, improved novel methods of district heating network (DHN) simulation are still being introduced in the literature. The subject of validation strategies for DHN simulation models emerges as one that has not been thoroughly analyzed before. Based on the considered subset of models reported in the literature, a general classification of the validation strategies of DHN models is proposed in this study. The proposed classification is based on two criteria: data and topology used in the validation case studies. This study provides insights into validation strategies for DHN models, their practical implementation and evaluation criteria, and the approaches used in the validation of these models. The standardization of DHN model validation approaches and the possibility to replicate the validation results seem to be limited. It seems that the dissemination of dedicated benchmarks or commonly accepted methodologies featuring evaluation criteria suitable for models’ intended applications could have a positive impact on the thoroughness of future DHN model validation and the replicability of validation results. To assist in future research, preliminary validation guidelines are proposed that may serve as a starting point in designing validation case studies for DHN models. Full article

Saussurea involucrata, a rare and endangered medicinal plant of the Asteraceae family, is primarily distributed in high-altitude rocky slopes and meadows at elevations of 2400–4100 m. In nature, this herb endures various abiotic stresses, including intense cold and ultraviolet radiation. In our study, transcriptomic profiles revealed that most of the differentially expressed genes (DEGs) enriched in stress response pathways, such as “response to water”, “response to abscisic acid”, “cold acclimation”, and “response to water deprivation”, were significantly upregulated after low-temperature treatment. In contrast, the majority of genes with lower expression were related to “photosynthesis”, “protein–chromophore linkage”, and “chloroplast thylakoid membrane”. Among them, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) database analysis revealed that approximately 20 DEGs were identified and annotated as dehydrin genes (DHNs). Quantitative PCR (qPCR) validation also confirmed that these DHNs were upregulated under cold stress. Moreover, SiDHN3, a new dehydrin gene, was cloned by Rapid Amplification of cDNA Ends (RACE). SiDHN3’s heterologous expression in E. coli showed enhanced salt, osmotic, freeze–thaw, and cold stress tolerance. A functional analysis of SiDHN3’s truncated derivatives revealed that the K-segment was critical for its protective function under freeze–thaw and cold stresses. Collectively, our study demonstrated the potential role of various DHNs as a functional protein, enhancing tolerance to cold stress in the high-altitude adaptation of plants. Full article

Fungal melanin plays a vital role in the survival, reproduction, infection, and environmental adaptation of plant pathogenic fungi. To develop innovative strategies for managing plant fungal diseases, comprehensive investigations into melanin are imperative. Such research is fundamental to elucidating the mechanistic basis of fungal pathogenesis and holds promise for the design of targeted interventions against melanin-mediated virulence determinants. This review systematically elaborates on the classification of fungal melanin in plant pathogens, provides a detailed analysis of the biosynthetic processes of 3,4-dihydroxyphenylalanine (DOPA) and 1,8-dihydroxynaphthalene melanin (DHN melanins), and reveals the catalytic functions and regulatory mechanisms of key enzymes within these pathways. Melanin modulates fungal virulence by influencing appressorial integrity and turgor pressure formation, thereby participating in the host infection process and the formation of overwintering sclerotia. Melanin provides stress resistance by protecting against extreme environmental factors, including UV radiation and high temperatures. It also has the capacity to absorb heavy metals, which increases pathogen survival under adverse conditions. Furthermore, the review also explores the mechanisms of action of melanin inhibitors that target plant pathogenic fungi, providing a theoretical foundation for developing efficient and environmentally friendly antifungal medications. The complex biosynthesis pathways and diverse biological functions of fungal melanin highlight its significant theoretical and practical importance for elucidating pathogenic mechanisms and formulating scientific control strategies. Full article

Paracoccidioides brasiliensis is a thermally dimorphic fungal pathogen and the main etiological agent of paracoccidioidomycosis (PCM), a neglected systemic mycosis endemic in Latin America. The virulence of P. brasiliensis is closely associated with its capacity to survive under hostile host conditions, including acidic environments. In this study, we demonstrate that acidic pH induces melanization in P. brasiliensis, modulates its cell wall composition, and alters the interaction with macrophages. Cultivation at acidic pH resulted in reduced fungal growth without compromising viability and triggered increased production of melanin-like pigments, as confirmed by enhanced laccase activity and upregulation of genes in the DHN-melanin biosynthetic pathway. Additionally, growth under acidic pH induced significant remodeling of the fungal cell wall, leading to increased chitin on the cell wall surface and reduced mannan content, while β-glucan levels remained unchanged. These modifications correlated with decreased viability to Congo Red, suggesting altered cell wall stability. Importantly, P. brasiliensis grown under acidic conditions exhibited reduced phagocytosis by RAW 264.7 macrophages, along with changes in nitric oxide and cytokine production, indicating potential mechanisms of immune evasion. Collectively, our findings suggest that environmental acidification promotes fungal adaptations that enhance survival and modulate host–pathogen interactions, contributing to P. brasiliensis virulence. Understanding how acidic pH regulates these processes provides new insights into the pathobiology of PCM and may contribute to understanding the mechanisms of fungal immune evasion. Full article

The integration of chirality into nanomaterials holds significant potential for improving molecular recognition and biomedical technologies. In this work, we fabricated novel chiral horned gold nanostructures (HNS) by controlling the concentration of chiral ligands L-/D-cysteine (Cys). The unique three-dimensional morphology with horns-rotational arrangement enables synergistic optimization of chiral optical responses and surface-enhanced Raman scattering (SERS) performance. The proposed chiral HNSs can be used to recognize amino acid enantiomers, in which homochiral amino acid has distinct affinities to the chiral HNSs of homogeneous handedness. The 4-mercaptobenzoic acid (4-MPBA)-modified D-HNS demonstrates significantly enhanced targeting affinity for D-amino acids in the Escherichia coli (E. coli) cell wall, enabling successful amplification of SERS signals and advancing bacterial detection methodologies. By demonstrating the rotation-selective interaction between chiral HNSs and circularly polarized light (CPL), D-HNS exhibits excellent photothermal conversion efficiency under right-handed circularly polarized light (RCP) irradiation. This enables the synergistic combination of targeted physical disruption and photothermal sterilization, which leads to efficient eradication of E. coli. The D-HNS hydrogel composite system further expands the practical application of photothermal sterilization. Altogether, chiral HNSs have achieved SERS detection of bacteria and efficient polarization photothermal sterilization, which helps further develop applications based on chiral nanomaterials. Full article

Understanding the relationship between geological and geomorphological processes is essential for reconstructing landscape evolution. This study examines how geology and geomorphology shape landscape development in central Brazil, focusing on the Natividade Group area. Sentinel-2 and SRTM data were integrated with geospatial analyses to produce two key maps: (i) a pedo-geomorphological map, classifying landforms and soil–landscape relationships, and (ii) a predictive geological–geomorphological map, based on a machine learning-based prediction of geomorphic units, which employed a Random Forest classifier trained with 15 environmental predictors from remote sensing datasets. The predictive model classified the landscape into six classes, revealing the ongoing interactions between geology, geomorphology, and surface processes. The pedo-geomorphological map identified nine pedoforms, grouped into three slope classes, each reflecting distinct lithology–relief–soil relationships. Resistant lithologies, such as quartzite-rich metasedimentary rocks, are associated with shallow, poorly developed soils, particularly in the Natividade Group. In contrast, phyllite, schist, and Paleoproterozoic basement rocks from the Almas and Aurumina Terranes support deeper, more weathered soils. These findings highlight soil formation as a critical indicator of landscape evolution in tropical climates. Although the model captured geological and geomorphological patterns, its moderate accuracy suggests that incorporating geophysical data could enhance the results. The landscape bears the imprint of several tectonic events, including the Rhyacian amalgamation (~2.2 Ga), Statherian taphrogenesis (~1.6 Ga), Neoproterozoic orogeny (~600 Ma), and the development of the Sanfranciscana Basin (~100 Ma). The results confirm that the interplay between geology and geomorphology significantly influences landscape evolution, though other factors, such as climate and vegetation, also play crucial roles in landscape development. Overall, the integration of remote sensing, geospatial analysis, and machine learning offers a robust framework for interpreting landscape evolution. These insights are valuable for applications in land-use planning, environmental management, and geohazard assessment in geologically complex regions. Full article

Importance of this study: Melanin synthesized through the oxidative polymerization of phenolic compounds exhibits a high molecular weight and has many physiological functions and activities. Main results: In this study, the key PKS1-1, PKS1-2, CMR1-1, and CMR1-2 genes for melanin biosynthesis and regulation from the highly genome-duplicated black yeast Hortaea werneckii Mo34, isolated from a deep-sea hydrothermal vent, were heterologously complemented in the ∆pks1 albino mutant K5 and the ∆cmr1 albino mutant CM7-2 of Aureobasidium melanogenum XJ5-1. Melanin formation in all the resulting transformants was restored, confirming that both the PKS1-1 and PKS1-2 genes from H. werneckii Mo34 were likely involved in the DHN melanin biosynthesis of A. melanogenum XJ5-1. Furthermore, the CMR1-1 and CMR1-2 genes from H. werneckii Mo34 could play significant roles in regulating melanin biosynthesis in A. melanogenum XJ5-1. Simultaneously, the expression of the PKS1 and THR1 genes involved in melanin biosynthesis was also enhanced in the transformants complemented with the CMR1-1 and CMR1-2 genes. The purified high-molecular-weight melanin from H. werneckii Mo34 exhibited excellent Fe²⁺-chelating, DPPH radical-scavenging, and superoxide radical-scavenging activities. Additionally, it actively inhibited the growth of Staphylococcus aureus and Pseudomonas putida. Conclusions: The black yeast H. werneckii Mo34 indeed had the DHN melanin biosynthesis pathway and the melanin produced by it had many potential applications. Full article