Search Results (158)

Biomass is a key renewable resource for advancing sustainable and circular energy systems. In contrast to prior reviews that predominantly emphasized well-established biomass types and conventional conversion technologies, this work offers a comparative synthesis that underscores underutilized feedstocks and emerging valorization pathways, providing a strategic perspective for sustainable process development. This review critically examines the current state of high-value-added bioproducts derived from biomass, focusing on their relevance to climate mitigation and resource efficiency. It explores sustainable process design strategies that enhance the environmental and economic performance of biomass conversion. Particular attention is given to recent advances in process intensification, including novel reactor configurations and heat integration techniques. The integration of sustainability assessment tools and multi-objective optimization approaches is analyzed to support data-driven decision-making. Multi-product biorefineries are discussed as central platforms for valorizing diverse feedstocks, supported by emerging models for supply chain integration. Present limitations such as feedstock heterogeneity, infrastructure constraints, and energy coupling challenges are reviewed, along with new opportunities in digitalization, modularization, and policy support. The novelty of this work lies in its cross-sectional synthesis of technologies, methodologies, and system-level strategies, offering a unified framework to unlock the full potential of biomass as a strategic vector for sustainable process development. Full article

Type 2 diabetes mellitus (T2DM) remains a global health challenge, prompting the development of novel α-glucosidase inhibitors (AGIs) to regulate postprandial hyperglycemia. This study reports the design, synthesis, and evaluation of indole-based Schiff base derivatives (4a–j) bearing a fixed methoxy group at the C₅ position. This substitution was strategically introduced to enhance lipophilicity, electronic delocalization, and π-stacking within the enzyme active site. Among the series, compound 4g (3-bromophenyl) exhibited the highest inhibitory activity (IC₅₀ = 10.89 µM), outperforming the clinical reference acarbose (IC₅₀ = 48.95 µM). The mechanism was supported by in silico analyses, such as the Density Functional Theory (DFT), molecular electrostatic potential (MEP) mapping, and molecular dynamics simulations, and CNN-based docking revealed that 4g engages in stable hydrogen bonding and π–π interactions with key residues (Asp327, Asp542, and Phe649), suggesting a potent and selective mode of inhibition. In silico ADMET predictions indicated favorable pharmacokinetic properties. Together, these results establish C₅–methoxy substitution as a viable strategy to enhance α-glucosidase inhibition in indole-based scaffolds. Full article

During the processes of excavation, restoration, and conservation of archaeological sites, it is common practice to perform physical and chemical characterization of the site materials. This is carried out to determine the best methods and materials for conserving and preserving the site. For this reason, techniques such as infrared spectroscopy and elemental analysis by X-ray fluorescence (XRF) are primarily used for chemical characterization, while mechanical tests such as the uniaxial compression test and hardness tests are used for physical and mechanical characterization. However, a common limitation is obtaining samples for destructive physical tests, such as compression tests, due to their invaluable cultural value. To address this problem, this work proposes the mechanical characterization of the material through nanoindentation. This technique requires a smaller sample size and can be performed in a timely manner by observing the resistance of each mineralogical phase present in the material. Thus, a preliminary predictive model of mechanical resistance is proposed based on the composition observed in the samples from the archaeological site of Cerro de los Remedios, located in the municipality of Comonfort, Guanajuato, Mexico. The samples were characterized using infrared spectroscopy, XRF, XRD, and SEM-EDS. The results indicate that the stone (caliche) is formed from 95.6–93% micrite calcite; 2.51–0.42% aluminosilicate; 3.14–1.89% high-calcium aluminosilicate; and 3.43–2.39 quartz or amorphous SiO₂. The proposed correlation models were adjusted to a linear function, a second-order polynomial, and a logarithmic function. In the M2–linear model, the non-linear effects generated by variables such as texture, porosity, phase adhesion, cement type, and cracks or discontinuities were not considered. In this model the best prediction of the experimental data was obtained within a variation of ±15%. Full article

Pyridine is a recalcitrant organic compound present in industrial wastewater that causes severe effects on the environment and the health of living beings, as it is considered a toxic, mutagenic, teratogenic, and carcinogenic agent. Therefore, this research explored the efficacy of a zinc oxide catalyst, doped with platinum nanoparticles and supported alumina through the precipitation method, for the photocatalytic degradation of pyridine using a fluidized bed reactor. A Box–Behnken experimental design was used to analyze the effect of the pH (4–10), the pyridine concentration (20–300 ppm), and the amount of catalyst (20–100 g). The X-ray diffraction (XRD) characterization results confirmed the hexagonal structure of the zinc oxide and the successful incorporation of platinum. Scanning electron microscopy (SEM) revealed a nano-bar morphology upon catalyst doping, favoring the photocatalytic activity. Pyridine removal of 57.7% was achieved under the following conditions: a pH of 4, 160 ppm of pyridine, and 100 g of catalyst. The process followed a pseudo-first-order model, obtaining the reaction constant k₁ = 1.943 × 10⁻³ min⁻¹ and the adsorption constant k₂ = 1.527 × 10⁻³ L/mg. The results showed high efficiency and stability of the catalyst in the fluidized bed reactor for pyridine degradation, especially under acidic conditions, representing a promising technological alternative for treating industrial wastewater contaminated with N-heterocycles such as pyridine. Full article

A brick kiln was experimentally studied to measure the transient temperature of hot gases and the compressive strength of the bricks, using pine wood as fuel, in order to evaluate the thermal performance of the actual system. In addition, a transient combustion model based on computational fluid dynamics (CFD) was used to simulate the combustion of natural gas in the brick kiln as a hypothetical case, with the aim of investigating the potential benefits of fuel switching. The theoretical stoichiometric combustion of both pine wood and natural gas was employed to compare the mole fractions and the adiabatic flame temperature. Also, the transient hot gas temperature obtained from the experimental wood-fired kiln were compared with those from the simulated natural gas-fired kiln. Furthermore, numerical simulations were carried out to obtain the transient hot gas temperature and NOx emissions under stoichiometric, fuel-rich, and excess air conditions. The results of CO₂ mole fractions from stoichiometric combustion demonstrate that natural gas may represent a cleaner alternative for use in brick kilns, due to a 44.08% reduction in emissions. Contour plots of transient hot gases temperature, velocity, and CO₂ emission inside the kiln are presented. Moreover, the time-dependent emissions of CO₂, H₂O, and CO at the kiln outlet are shown. It can be concluded that the presence of CO mole fractions at the kiln outlet suggests that the transient combustion process could be further improved. The low firing efficiency of bricks and the thermal efficiency obtained are attributed to uneven temperatures distributions inside the kiln. Moreover, hot gas temperature and NOx emissions were found to be higher under stoichiometric conditions than under fuel-rich or excess of air conditions. Therefore, this work could be useful for improving the thermal–hydraulic and emissions performance of brick kilns, as well as for future kiln design improvements. Full article

Type 2 diabetes mellitus (T2DM) demands safer and more effective therapies to control postprandial hyperglycemia. Here, we report the synthesis and in vitro evaluation of ten salicylic acid-derived Schiff base derivatives (4a–4j) as α-glucosidase inhibitors. Compounds 4e, 4g, 4i, and 4j exhibited potent enzyme inhibition, with IC₅₀ values ranging from 14.86 to 18.05 µM—substantially better than acarbose (IC₅₀ = 45.78 µM). Molecular docking and 500 ns molecular dynamics simulations revealed stable enzyme–ligand complexes driven by π–π stacking, halogen bonding, and hydrophobic interactions. Density Functional Theory (DFT) calculations and molecular electrostatic potential (MEP) maps highlighted key electronic factors, while ADMET analysis confirmed favorable drug-like properties and reduced nephrotoxicity. Structure–activity relationship (SAR) analysis emphasized the importance of halogenation and aromaticity in enhancing bioactivity. Full article

Background/Objectives: Chloroquine (CQ) and hydroxychloroquine (HCQ) have been the subject of debate in the treatment of COVID-19 due to the lack of conclusive evidence regarding their efficacy and safety. Our study aims to investigate the molecular interaction between the enantiomers of CQ and HCQ with angiotensin-converting enzyme 2 (ACE2), focusing on the binding mechanism, affinity, and selectivity. Methods: We used in silico methods, including molecular docking, molecular dynamics, and binding free energy calculations using the MM-PBSA method, to evaluate the interaction between the enantiomers of CQ and HCQ with ACE2. Results: We identified three main interaction sites on ACE2 (α, β, and γ) with distinct characteristics based on the pocket size, hydrophilic/hydrophobic characteristics, and affinity energy. We observed that protonation states and ionic strength significantly influence the binding affinity and specificity. In particular, the selectivity of the β-site, characterized by its smaller size and hydrophilic residues, is preferential for species with the (R) configuration, whereas the α and γ binding sites, with a larger size and amphiphilic residues, have greater affinity for the (S) enantiomer of CQ and HCQ. Furthermore, ionic strength can affect ligand binding by modulating electrostatic interactions, molecular conformation, solvation, and the stability of the complex. Conclusions: Our findings reveal that protonation states and the ionic strength substantially impact the binding affinity and specificity, regulated by spatial and polar–electrostatic complementarity, as well as hydrophobic contributions. These results suggest that understanding the interaction between CQ and HCQ enantiomers with ACE2 could be useful for the design of novel therapies against COVID-19. Full article

Brettanomyces bruxellensis has been described as the main spoilage microorganism in wines due to its ability to produce volatile phenols, which negatively impact the final product’s organoleptic properties. This yeast can grow and survive in environments that are too nutritionally poor and stressful for other microorganisms, and one of the stressful conditions it can endure is the high alcohol content in wine. In this study, cell wall morphology and the expression of some genes related to its composition were characterized under increasing ethanol concentrations to establish a possible ethanol resistance mechanism. B. bruxellensis LAMAP2480 showed greater resistance to β-1,3-glucanase activity when grown in media supplemented with 5% or 10% ethanol compared with the control assay (without ethanol). Transmission electron microscopy showed no significant differences in cell wall thickness during the different adaptation stages. However, the amount of wall polysaccharides and chitin briefly increased at 1% ethanol but returned to baseline at 5% and 10%. The amount of wall-associated protein increased progressively with each increment in ethanol concentration. In addition, overexpression of the ROM2 and KNR4/SMI1 genes was observed at 10% ethanol. These results suggest that the integrity of the cell wall might play an important role in the adaptation of B. bruxellensis to an ethanol-containing medium. Full article

An analysis of entropy generation and a performance comparison are carried out for a solid oxide fuel cell with an embedded porous pipe in the air supply channel of a mono-block-layer-build geometry (MOLB-PPA SOFC) and a planar geometry with trapezoidal baffles inside the fuel and air channels (P-TBFA SOFC). The results for power density at different current densities are discussed. Also, a comparison of the field of species concentration, temperature, and current density on the electrode–electrolyte interface is analyzed at a defined power density. Finally, a comparison of maps of the local entropy generation rate and the global entropy generation due to heat transfer, fluid flow, mass transfer, activation loss, and ohmic loss are studied. The results show that the MOLB-PPA SOFC reaches a 7.5% higher power density than the P-TBFA SOFC. Furthermore, the P-TBFA SOFC has a more homogeneous temperature distribution than the MOLB-type SOFC. The entropy generation analysis indicates that the MOLB-PPA SOFC exhibits lower global entropy generation due to heat transfer compared to the P-TBFA SOFC. The entropy generation due to ohmic losses is predominant for both geometries. Finally, the total irreversibilities are 24.75% higher in the P-TBFA SOFC than in the MOLB-PPA SOFC. Full article

This study investigated the chemical, thermal, and mechanical properties of segmented polyurethanes (SPUs) synthesized using less common biodegradable polyester polyols, specifically poly(adipate) (PAD) and poly(sebacate) (PSC), to evaluate their potential as nerve guidance conduits (NGCs) in peripheral nerve regeneration. The synthesis of novel 4,4′ methylene-bis-cyclohexyl diisocyanate (HMDI) SPUs was conducted in a two-step process: prepolymer formation and chain extension with 1,4-butanediol (BO) or 1,4-butanediamine (BA). SPUs were synthesized with two molar ratios—polyol:HMDI:BA/BO at 1:2:1 and 1:3:2 for the PAD:HMDI:BA system—to optimize mechanical properties. 1HRMN analysis verified the expected chemical structure of SPUs, whereas Raman and IR spectroscopy confirmed successful polyurethane synthesis. X-ray diffractograms showed that PAD-based SPUs (SPUPAD) were amorphous while PSC-based SPUs (SPUPSC) exhibited semi-crystalline behavior. SPUPAD showed only one degradation stage by TGA, while DSC showed one thermal event. In contrast, SPUPSC exhibited two degradation stages and three thermal events that confirmed phase separation. The longitudinal tensile properties of an NGC fabricated from SPUA-PAD-2 (PAD:HMDI:BA (1:3:2)) after 30 days of immersion in water (25 °C) showed a lower modulus (4.46 ± 0.5 MPa) than native intact nerves (15.87 ± 2.21 MPa) but a similar modulus to extracted nerves (8.19 ± 7.27 MPa). This system exhibited a longitudinal tensile force of 11.1 ± 1.6 N, which is lower than that of peripheral nerves (19.85 ± 7.21 N) but higher than that of commercial collagen-based nerve guide conduits (6.89 ± 2.6 N). The observed properties suggest that PUA-PAD-2 has potential as a biomaterial for nerve regeneration applications. Full article

Obesity is a growing global health concern, contributing to diseases such as cancer, autoimmune disorders, and neurodegenerative conditions. Adipose tissue dysfunction, characterized by abnormal adipokine secretion and chronic inflammation, plays a key role in these conditions. Adipose-derived extracellular vesicles (ADEVs) have emerged as critical mediators in obesity-related diseases. However, the study of mature adipocyte-derived EVs (mAdipo-EVs) is limited due to the short lifespan of mature adipocytes in culture, low EV yields, and the low abundance of these EV subpopulations in the circulation. Additionally, most studies rely on rodent models, which have differences in adipose tissue biology compared to humans. To overcome these challenges, we developed a standardized approach for differentiating human preadipocytes (preAdipos) into mature differentiated adipocytes (difAdipos), which produce high-yield, human adipocyte EVs (Adipo-EVs). Using visceral adipose tissue from bariatric surgical patients, we isolated the stromal vascular fraction (SVF) and differentiated preAdipos into difAdipos. Brightfield microscopy revealed that difAdipos exhibited morphological characteristics comparable to mature adipocytes (mAdipos) directly isolated from visceral adipose tissue, confirming their structural similarity. Additionally, qPCR analysis demonstrated decreased preadipocyte markers and increased mature adipocyte markers, further validating successful differentiation. Functionally, difAdipos exhibited lipolytic activity comparable to mAdipos, supporting their functional resemblance to native adipocytes. We then isolated preAdipo-EVs and difAdipo-EVs using tangential flow filtration and characterized them using bulk and single EV analysis. DifAdipo-EVs displayed classical EV and adipocyte-specific markers, with significant differences in biomarker expression compared to preAdipo-EVs. These findings demonstrate that difAdipos serve as a reliable surrogate for mature adipocytes, offering a consistent and scalable source of adipocyte-derived EVs for studying obesity and its associated disorders. Full article

The aim of this work was to carry out a microsynthesis of a graft copolymer from different starch sources with polycaprolactone (PCL) and to evaluate its effects on enthalpy during synthesis via differential scanning calorimetry (DSC). The copolymer was characterized via FTIR and pasting profile techniques. FTIR studies revealed that starch–PCL graft copolymerization was carried out on all starch sources. The pasting profile revealed that the copolymer presented low viscosity values (heating and cooling stages), compared with those of native starches. This finding indicates that copolymerization took place on the surface of the starch granules. Cassava starch presented the highest enthalpy values at synthesis temperatures of 150 °C and 160 °C. Full article

Sporothrix schenckii is a pathogenic fungus of worldwide distribution and one of the etiological agents of sporotrichosis. The cell wall is the first point of contact with host cells; therefore, its composition has been widely studied. It has a cell wall composed of chitin, β-glucans, and glycoproteins modified with N-linked and O-linked glycans. Protein O-linked glycosylation is mediated by two gene families, PMT and MNT. Therefore, we evaluated the relevance of protein O-linked glycosylation during the interaction of S. schenckii with the host. Independent silencing of the MNT1 and PMT2 was accomplished by interference RNA. Morphological analyses revealed defects in cell morphology in both yeast and mycelial cells; however, these defects differed between MNT1 and PMT2 silencing. Subsequently, the cell wall was characterized, and the silencing of these genes markedly changed cell wall organization. When the silenced strains interacted with human peripheral blood mononuclear cells, a reduced ability to stimulate the proinflammatory cytokines IL-6 and TNFα was found. However, the PMT2-silenced mutants also stimulated higher levels of IL-10 and IL-1β. Interaction with macrophages and neutrophils was also altered, with increased phagocytosis and decreased extracellular trap formation in both sets of silenced strains. Survival assays in Galleria mellonella larvae showed that silencing of any of these genes reduced the ability of S. schenckii to kill the host. In addition, the mutant strains showed defects in the adhesion to extracellular matrix proteins. These data indicate that MNT1 and PMT2 are relevant for cell wall synthesis and interaction with the host. Full article

Minerals have played a fundamental part in prebiotic chemistry on Earth, catalyzing the synthesis of inorganic and even organic molecules, including macromolecules such as RNA or DNA. Minerals based on silica are some of the first inorganics to be found in very ancient mineral fossils. These minerals or even volcanic glasses rich in silica, such as obsidians (a naturally volcanic glass, which is in fact an igneous rock), play an important role as supporting materials for obtaining the silico-carbonates of alkaline earth metals (usually called biomorphs). This is because, in most radiolarians, diatoms, and foraminifera, their external shells are made up of silica (SiO₂). However, it has yet to be evaluated whether the silica contained in the minerals present in the prebiotic era of the Earth interacted with the chemical elements that were also present during that era. To evaluate whether obsidian participated in the formation of the first inorganic structures of pioneering organisms, this study aimed to synthesize calcium and barium biomorphs on igneous rock and to show that dissolved organic and inorganic molecules might have interacted with the molecules of obsidian, producing a plethora of shapes that mimicked the cherts of the Precambrian. Full article

The increase in multidrug-resistant organisms worldwide is a major public health threat driven by antibiotic overuse, horizontal gene transfer (HGT), environmental drivers, and deficient infection control in hospitals. In this article, we discuss these factors and summarize the new drugs and treatment strategies suggested to combat the increasing challenges of multidrug-resistant (MDR) bacteria. New treatments recently developed involve targeting key processes involved in bacterial growth, such as riboswitches and proteolysis, and combination therapies to improve efficacy and minimize adverse effects. It also tackles the challenges of the Gram-negative bacterial outer membrane, stressing that novel strategies are needed to evade permeability barriers, efflux pumps, and resistance mechanisms. Other approaches, including phage therapy, AMPs, and AI in drug discovery, are also discussed as potential alternatives. Finally, this review points out the urgency for continued research and development (R&D), industry–academic partnerships, and financial engines to ensure that MDR microbes do not exceed the value of antibacterial therapies. Full article