Hydrochars were synthesized from cellulose and nanocellulose, and their structural, chemical, textural, and morphological evolutions were systematically investigated. Unlike most recent studies focused on a single cellulose-based precursor, isolated HTC parameter, catalytic/additive-assisted route, or specific application, this work provides a comparative multi-variable evaluation of α-cellulose- and nanocellulose-derived hydrochars. For α-cellulose-derived hydrochars (HC), the effects of temperature, residence time, precursor loading, and agitation speed were examined, whereas for nanocellulose-derived hydrochars (HN), the influence of temperature and initial pH was evaluated. The resulting materials were characterized by elemental analysis, FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, N2 adsorption–desorption measurements, while multivariate statistical tools were used to correlate processing conditions with compositional, structural, and fuel-related properties. HC showed progressive carbonization with increasing HTC severity, as indicated by decreasing the H/C and O/C atomic ratios, higher carbon content, and improved higher heating value (HHV). FTIR spectra indicated the formation of oxygenated functional groups and aromatic domains, while XRD patterns showed broad amorphous halos typical of non-graphitizing carbon. SEM images revealed irregular carbonaceous matrices containing micrometer-sized spherical particles. For HN, the influence of temperature (200–260 °C) and initial pH (3.3 and 12) was examined. The CHN elemental analysis showed that the acidic initial reaction medium favored dehydration, deoxygenation, and carbon enrichment, whereas the initially alkaline condition delayed carbonization. Overall, this systematic comparison demonstrates how precursor type and HTC processing variables modulate hydrochar yield, composition, structure, morphology, and fuel-related properties, providing a clearer basis for the rational design of cellulose- and nanocellulose-derived hydrochars.
We establish new sharp regularity results for convex supersolutions of fully nonlinear elliptic equations with Hamiltonian terms, extending the classical Hopf-Oleĭnik boundary point lemma to a broader class of operators. Specifically, we analyze fully nonlinear equations of the formPλ,Λ,γ,μ,m(D2u,Du,x)=f(x),where Pλ,Λ,γ,μ,m represents a class of extremal Pucci-type operators with gradient dependence and unbounded coefficients. By refining barrier techniques introduced in [1] and employing viscosity solution methods, we derive sharp interior regularity estimates for semiconvex supersolutions of Pλ,Λ,γ,μ,m. Our results not only generalize classical boundary type estimates for fully nonlinear PDEs but also provide a unified framework to handle gradient-dependent structures with different growth regimes. In particular, we establish a non-homogeneous Hopf-Oleĭnik lemma that remains valid in the presence of unbounded nonlinearities, significantly strengthening previous results in this direction. These findings contribute to the broader understanding of nonlinear PDEs, with implications in geometric analysis and optimal control.
Agricultural systems face unprecedented threats from climate change-induced environmental stresses (e.g., drought, salinity, and heatwaves). These environmental stresses limit crop productivity, degrade soil health, and threaten global food security, highlighting the urgent need for innovative and sustainable solutions. Harnessing soil and plant-associated microbiomes offers transformative potential to enhance plant resilience and sustainability. However, translating lab-based plant-microbiome research into scalable agricultural applications remains a significant challenge. This review explores the dynamic interplay between plants and their associated microbiomes under abiotic stresses, focusing on the mechanisms by which plants recruit and modulate microbial communities in the rhizosphere, phyllosphere, and endosphere. We conceptualize how environmental abiotic stresses alter plant–microbe interactions and highlight microbiome-mediated strategies for stress mitigation. Finally, we evaluated practical interventions (e.g., synthetic microbial communities (SynComs), host-mediated microbiome engineering (HMS), and metabolites) for their potential to enhance agricultural resilience. Bridging lab-based discoveries with the success of field applications will require overcoming key scientific and translational challenges related to improving plant–microbe communication, microbial community stability, product performance, ecological risks, and interdisciplinary collaboration. We advocate for systems-based approaches that integrate plant and microbiome engineering, metabolic and genetic innovations, agronomic practices, and policy frameworks to accelerate the adoption of new and sustainable tools. We identified key research gaps, including long-term ecological impacts and optimization of microbiome-host compatibility. By integrating cutting-edge science with scalable, real-world solutions, plant-microbiome interactions can significantly contribute towards climate-smart agriculture, supporting ecosystem resilience in an era of global change.
Lectins are carbohydrate-binding proteins involved in diverse biological processes and with increasing relevance in biotechnological applications. In this study we report the structural characterization of a lectin from the marine red alga Amansia multifida (AML). Mass spectrometry analysis revealed two major isoforms with molecular masses of 28,388 Da and 28,661 Da. The primary structure of a lectin with a molecular weight of 28,661 Da was determined by combination of N-terminal Edman degradation, tandem mass spectrometry, and RACE-PCR, revealing four tandemly repeated domains and high sequence identity with members of the OAAH (Oscillatoria agardhii agglutinin homologous) lectin family. Notably, A. multifida belongs to the order Ceramiales, suggesting a broader taxonomic distribution for this lectin family, previously restricted to species from the order Gigartinales. Secondary and tertiary structure analyses suggested a predominantly β-sheet conformation and a β-barrel fold, characteristic of OAAH lectins. Molecular docking showed conserved recognition of mannosylated glycans, supported by the presence of the QWGGREGPI motif in all carbohydrate recognition domains. Although AML did not exhibit direct antibacterial or antibiofilm activity, it was able to agglutinate Escherichia coli and Staphylococcus aureus strains, indicating potential interactions with mannoside-rich surface glycans. These findings enhance our understanding of marine lectin diversity and highlight AML as a new lectin of OAAH family.
Cowpea severe mosaic virus (CPSMV) represents a major constraint for cowpea (Vigna unguiculata (L.) Walp.) cultivation. However, the metabolic basis underlying CPSMV resistance remains poorly understood. Given the importance of metabolism for plant defence against pathogens, we hypothesized that cowpea resistance to CPSMV is associated to the activation of defence-related pathways from both primary and secondary metabolisms. We investigated the metabolic dynamics associated with CPSMV infection in the resistant cowpea genotype Macaibo using a time-resolved, network-based metabolomics approach. Conventional RT-PCR suggests that the intensity of the CPSMV coat protein band increased in the first eight Hours After CPSMV Inoculation (HAI) but appeared reduced in the following 72 HAI. Metabolomic analyses revealed that CPSMV infection had little impact on secondary metabolism, whereas several primary metabolites were significantly altered over time. Transient increases in fumarate, pyruvate, and several amino acids, including alanine, asparagine, glutamine, glutamate, isoleucine, leucine, proline, serine, threonine, and valine, were observed at 48 HAI compared with mock-treated leaves. Network analysis indicated that overall metabolic network density and heterogeneity remained relatively stable during infection. However, a highly connected metabolic module composed of the branched-chain amino acids (BCAAs) isoleucine, leucine, and valine emerged in infected leaves. Our results indicate that CPSMV infection reshapes primary metabolic dynamics without extensive alterations in secondary metabolism during early infection in cowpea leaves. Despite these metabolic adjustments, the overall metabolic network structure remained stable, suggesting that a robust metabolic reprograming, including the activation of BCAA-associated pathways, may help buffer viral perturbation in cowpea leaves.
