Search Results (1,115)

Echinophora tenuifolia subsp. sibthorpiana is an aromatic and traditionally used plant whose phytochemical diversity and pharmacological potential remain incompletely characterized. This study aimed to integrate comprehensive chemical profiling with antioxidant, antimicrobial, and antiproliferative evaluations of an acidified methanolic extract prepared from its aerial parts. Phenolic constituents, volatile compounds, and fatty acids were characterized using LC–MS/MS, GC–MS, and GC–FID, respectively. Antioxidant capacity was assessed using DPPH and ABTS assays, antimicrobial effects were evaluated by disc diffusion and broth microdilution methods, and antiproliferative activity was investigated in six human cancer cell lines and non-cancerous BEAS-2B cells. Apoptosis induction and cell-cycle alterations were further examined by flow cytometry. The extract contained a high total phenolic content of 181.78 ± 5.03 mg GAE/g and exhibited substantial DPPH and ABTS radical scavenging activities of 333.65 ± 2.94 and 262.18 ± 6.80 mg TE/g, respectively. LC–MS/MS analysis identified rutin hydrate, quinic acid, chlorogenic acid, narcissin, and vicenin-2 as the predominant non-volatile constituents. The essential oil was dominated by methyl eugenol (51.10%) and Δ-3-carene (32.23%), whereas lauric acid (29.71%) was the major fatty acid. The extract also exhibited measurable antimicrobial activity and concentration-dependent cytotoxicity, with the greatest sensitivity observed in MCF-7 breast cancer cells (IC₅₀ = 32.96 ± 4.80 μg/mL), followed by A549 and MDA-MB-231 cells. However, the relatively close IC₅₀ values observed in cancer and non-cancerous BEAS-2B cells indicated limited cancer-cell selectivity under the tested conditions. Flow-cytometric analyses demonstrated marked apoptosis induction in MCF-7 cells, reaching 57.93 ± 1.80%, together with a cell-line-dependent accumulation in the G2/M phase. Collectively, these findings indicate that E. tenuifolia subsp. sibthorpiana is a chemically diverse source of plant-derived bioactive compounds with notable radical scavenging and measurable antimicrobial and cytotoxic effects. Further bioactivity-guided fractionation and mechanistic studies are required to identify the active constituents and clarify their pharmacological relevance and selectivity. Full article

Reinforced concrete structures in marine environments are subjected to severe deterioration, particularly in tidal zones. The development of intrinsically hydrophobic concrete through internal modification provides a promising strategy to mitigate this challenge. This study employed sodium methyl silicate (SMS) as a hydrophobic agent to prepare recycled fine aggregate concrete (RFAC), which was subsequently subjected to accelerated indoor chloride dry–wet cycling. The deterioration behavior of RFAC and the degradation mechanism of the SMS-induced hydrophobic film during dry–wet cycling were investigated through evaluations of mechanical performance, hydrophobicity, chloride resistance, microstructure, phase composition, pore structure, chemical bonding, and functional groups. The results show that SMS improves the hydrophobicity of RFAC but inhibits its hydration process. The optimal SMS dosage for RFAC under dry–wet cycling is 9‰, which achieves a balance between hydrophobicity enhancement and pore structure optimization. Compared with ordinary RFAC, the specimen exhibits 12.9‰ and 17.6% increases in compressive strength and RDEM, respectively, after 30 cycles, accompanied by reductions of 25.8%, 52.7%, and 80.0% in peak free chloride content, chloride erosion depth, and convection zone depth, respectively. RFAC with 9‰ SMS exhibits a denser matrix with lower porosity and fewer corrosion products. SMS enhances chloride resistance mainly by reducing water transport and chloride ion ingress through hydrophobic modification. Dry–wet cycling gradually deteriorates the SMS-induced hydrophobic film through the weakening of Si-C-related structures, while the Si-O-Si framework remains relatively stable. A quantitative correlation between the contact angle and free chloride ion content is established, and the modified Lucas–Washburn equation provides a reasonable description of chloride ion penetration depth. Full article

This study investigates the influence of Lewis acids on a novel stratified (Co²⁺,Pd²⁺)₂SiO₄-Pd⁰ olivine catalyst for the Heck–Mizoroki coupling of iodobenzene and methyl acrylate. Comprehensive characterization (ICP-OES, Raman, P-XRD, XPS) confirms the successful synthesis of a material with surface-incorporated Pd²⁺ and bulk Pd⁰ nanoparticles within a Co₂SiO₄ matrix. The promoter-free system with triethylamine base achieved the highest initial rate of 3.92 × 10⁻⁷ mol.s⁻¹ with an average rate of 1.18 × 10⁻⁷ mol.s⁻¹, despite a 30 min induction period. However, ZnCl₂, the weakest acid, showed the most substrate activation and lowered the induction period to 10 min, while AlCl₃ also reduced the induction period to 20 min. FeCl₃ showed the poorest performance, attributed to redox-mediated site poisoning rather than hydrolysis. Selectivity over the catalyst was maintained at >99 mol% towards methyl cinnamate irrespective of the Lewis acid or base used. However, recycling of the catalyst led to a gradual decrease in selectivity toward methyl cinnamate from >99 mol% to ~94.6 mol% over three cycles, while conversion remained consistently high at >99 mol% across all cycles, indicating that the catalyst’s primary activity was largely preserved despite surface evolution toward side-product formation. Lewis acids were found to function primarily as surface modifiers and/or productive substrate activators, with stronger Lewis acids also targeting the olivine framework, as seen from the preferential leaching of Co relative to Pd. Full article

Rice is a globally important staple crop and a major dietary source of inorganic arsenic (As). Compared with upland crops, flooded rice cultivation profoundly alters soil redox conditions, making paddy soils one of the most active agricultural interfaces for As mobilization, transformation, and food-chain transfer. While previous research has primarily focused on total As and inorganic As [As(III)/As(V)], methylated and thiolated As species also carry critical agronomic and health implications. Dimethylarsinic acid (DMA) can accumulate in grain and induce straighthead disease, whereas dimethylmonothioarsenate (DMMTA) shows substantially higher toxicity and uptake potential; DMMTA root uptake can be approximately 10 times higher than DMA, and its straighthead-inducing potency can exceed DMA by more than fivefold. This review synthesizes the sources, biogeochemical transformations, plant uptake, grain accumulation, safety assessment, and management implications of As along the paddy soil–rice–grain continuum. Particular emphasis is placed on how water regimes, redox potential, Fe/Mn/Al oxides, sulfur cycling, dissolved organic matter (DOM), microbial functional genes, and crop genotypes regulate diverse As species. Quantitative evidence indicates that alternate wetting and drying (AWD) can reduce grain total As and inorganic As by medians of 32% and 22%, respectively, but may increase grain cadmium (Cd) by a median of 58%; meanwhile, DMA and DMMTA can account for approximately 10–90% and 1–21% of total grain As, respectively, emphasizing that grain-As risk cannot be evaluated using inorganic As alone. Future research should establish speciation-based monitoring systems for inorganic, methylated, and thiolated As; develop process models linking water regime, Fe/S cycling, microbial transformations, and plant transport; and translate these mechanisms into field decision tools that balance As–Cd risk reduction, crop yield, and rice safety under changing environmental conditions. Full article

Microalgal lipid production requires cultivation strategies that reduce freshwater demand while maintaining biomass productivity and improving the quality of fatty acid methyl ester (FAME) profiles for downstream applications. In this context, salinity is a relevant but still insufficiently characterized factor, particularly for Auxenochlorella protothecoides, whose response to salt stress in terms of growth dynamics, lipid productivity, and FAME composition remains poorly understood. This study investigated the effect of NaCl concentrations ranging from 0 to 50 g L⁻¹ on the growth, lipid accumulation, FAME profile, and predicted biodiesel-related properties of A. protothecoides. Growth kinetics were described using logistic and Gaussian models. The highest carrying capacity was observed at 10 g L⁻¹ NaCl, whereas the modeled optimum for specific growth rate occurred under moderate salinity, close to 20 g L⁻¹ NaCl. Lipid analyses showed that C16–C18 fatty acids (FAs) dominated across treatments, accounting for more than 90% of total FAMEs, and that increasing salinity shifted the profile from a more saturated C16:0-rich composition toward higher proportions of unsaturated C18 FAs, particularly oleic and linoleic acids. Biodiesel property estimations indicated that mild salinity (5 g L⁻¹) improved some fuel-relevant parameters relative to the other salinity treatments, including cetane number, iodine value, cold-flow-related properties, and oxidative stability. Nevertheless, the predicted viscosity values were below the EN 14214 specification range for all treatments, and oxidative stability at 5 g L⁻¹ only marginally met the European minimum requirement, indicating partial rather than full compliance with biodiesel standards. These findings indicate that salinity can be used as a practical tool to tune biomass production and lipid quality in A. protothecoides, supporting its potential use in microalgal biorefineries and oleochemical applications. Furthermore, the ability of the strain to tolerate saline conditions may support the future use of brackish water, seawater, or saline waste streams, potentially reducing freshwater demand; however, this environmental benefit was not quantified in the present study and should be validated through dedicated water-footprint or life-cycle assessment. Direct biodiesel application also remains limited by incomplete compliance with fuel standards, and further optimization through cultivation in real saline or wastewater-based media, process scale-up, blending, or downstream upgrading will be required to improve industrial feasibility. Full article

Background: DNA methylation is a key epigenetic mechanism whose dynamics are closely linked to ageing. Modern epigenetic clocks predict biological age based on the average methylation level. The concept of “epigenetic rejuvenation” posits that at early stages of development, the biological age of the embryo may decrease, reaching a minimum (“ground zero”) at the gastrulation stage. However, standard averaging methods may not account for important rearrangements in the internal structure of methylation. Objective: To apply the apparatus of information theory and topological data science to the analysis of scNMT-seq data and to test whether DNA methylation entropy decreases from stage E4.5 to E6.5, which would correspond to an approach towards the biological zero state. Methods: Publicly available scNMT-seq data (GSE121690) were analyzed. Five entropy measures were calculated for each cell (Shannon, Renyi, Tsallis, LZ-complexity, local gradient entropy (entropy of variations in the smoothed histogram of the methylation distribution), and persistent entropy (PE)—a topological complexity measure). For the five-dimensional entropy feature space, a Rips complex was constructed, and persistence diagrams H_0 and H_1 were computed. Results: All five entropy measures decreased significantly, with LZ complexity showing the largest relative reduction (−28.4%) and the strongest independent signal (partial r = −0.181). Among all the complexity measures studied, LZ complexity exhibited the largest relative reduction, underscoring its heightened sensitivity to the progressive ordering of the epigenetic landscape. Notably, the ternary encoding of LZ complexity showed strong correlation with Shannon entropy (r = 0.71), indicating that algorithmic complexity, when accounting for partial methylation states, aligns closely with statistical entropy while retaining sensitivity to spatial order. The consistency of results across binary and ternary encodings confirms the robustness of LZ complexity as a structural biomarker. Persistent entropy confirmed the general dynamics (decrease from 15.91 to 14.89, p = 0.01). Topological analysis of the multidimensional space revealed a qualitative reorganization: at stage E6.5, stable cyclic structures (H₁) emerge, while at E4.5 the space is dominated by a single large-scale cycle. Null model validation confirmed that the observed H₁-cycles are genuine topological features rather than random fluctuations. Comprehensive topological characterization showed that normalized persistent entropy increases from 0.846 to 0.882 (p < 0.001), while maximum persistence decreases from 0.446 to 0.218 (p < 0.001), reflecting a transition from a homogeneous state to structured diversification—multiple, evenly distributed cycles corresponding to distinct cell lineages. Consistent with this, regional disorder (RE/RD) at the single-cell level decreases from E4.5 to E6.5 (RE: −25.5%, RD: −27.4%, p < 10⁻¹³), while global entropy also decreases, together painting a picture of epigenetic rejuvenation as ordered consolidation at the whole-genome scale. An SVM model trained on 15 entropy and structural features achieved stage classification with an accuracy of 93.4% and AUC of 0.981, confirming the diagnostic potential of the approach. Conclusions: The decrease in DNA methylation entropy from E4.5 to E6.5 corresponds to an approach to “ground zero”—the point of minimum biological age in embryogenesis—and supports the hypothesis of a link between decreasing entropy and epigenetic rejuvenation. The addition of topological analysis reveals the hidden organization of epigenetic diversity, showing that ordering does not lead to homogenization but is accompanied by the formation of distinguishable cell lineages. Full article

The rapid expansion of space exploration has increased the demand for lightweight structural materials capable of maintaining performance under extreme thermal conditions. Carbon fibre-reinforced polymers (CFRPs) offer high specific strength and low density; however, their application in cryogenic environments remains challenging due to the brittleness of epoxy matrices, which are susceptible to cracking at low temperatures and under thermal cycling. In this work, two strategies were investigated to improve the damage tolerance of epoxy nanocomposites: (i) the use of a biscitraconimide-based (BCI) resin and (ii) the incorporation of methyl methacrylate–butadiene–styrene (MBS) core–shell particles. Low additive contents were evaluated to identify formulations compatible with prepreg manufacturing. The incorporation of 2 wt.% of MBS core–shell particles significantly improved the impact resistance of the nanocomposites and was selected for CFRP laminate production. When applied to CFRPs, the modified matrix maintained the overall tensile behaviour while increasing the interlaminar fracture toughness by 102% and 122% at room (RT) and cryogenic temperatures (CT), respectively. These findings demonstrate that matrix modification using low-content toughening is an effective strategy to enhance the cryogenic performance of CFRPs, contributing to the development of lighter and more resilient composite structures for next-generation space systems. Full article

Singlet oxygen is produced by light-dependent excitation of molecular oxygen using photosensitizers. Using blue light and riboflavin (RF) or riboflavin phosphate (RFP) as photosensitizers, we studied the reaction of singlet oxygen with tertiary amines in aqueous solution because many are used as biochemical buffers and as electron donors in photoreduction reactions. The reactions of singlet oxygen with multiple tertiary amines, including ethylenediamine tetraacetic acid (EDTA), bicine, and triethanolamine (TEOA), produced micromolar hydrogen peroxide (H₂O₂) as the stable end product. For bicine and TEOA, but not EDTA, H₂O₂ yield increased as pH increased due to their higher amine pKa values. A white LED used in conjunction with riboflavin and tertiary amines also produced H₂O₂, a contaminant likely to form during tissue culture manipulations. Direct photoreduction of 2,6-dichlorophenolindophenol and 2,3-dimethoxy-5-methyl-p-benzoquinone was achieved using blue light, RF or RFP, and tertiary amines as electron donors. With RF, EDTA was the optimal electron donor for both substrates, whereas with RFP, bicine and TEOA were superior to EDTA. Photochemical redox cycling of both quinones produced H₂O₂ via singlet oxygen-dependent re-oxidation of reduced quinols. Several amine buffers, including HEPES and PIPES, reacted with singlet oxygen to produce H₂O₂ but did not function as electron donors in quinone photoreduction assays. Full article

Cervical cancer (CC) affects women worldwide, and more than 95% of cases are caused by persistent infection with high-risk human papillomavirus (HR-HPV), such as type 16, which promotes the progression of precancerous lesions to cancer. This study aimed to identify differentially expressed proteins (DEPs) in biopsies from patients with HPV16+ low-grade squamous intraepithelial lesions (LSILs) and from patients with HPV16+ squamous cell carcinoma (SCC) compared with those from HPV-negative normal cervical tissue (NCT HPV−) controls. The samples were analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) using a data-independent acquisition (DIA) approach. Data processing and differential protein expression analysis were performed with the DIA-NN software (Data-Independent Acquisition Neural Networks), followed by bioinformatics analyses, including Venn diagrams, pathway enrichment, functional interactome, The Cancer Genome Atlas (TCGA)-SCC data integration, and Western blot detection. In total, 1607 DEPs associated with cell adhesion and extracellular matrix proteins were identified in LSILs, whereas 1516 DEPs associated with catalytic and transport activities were identified in SCC; the proteins overexpressed in LSILs (332) were enriched in processes such as metabolism, immune response activation, and stress and cell death responses. In contrast, proteins overexpressed in SCC (205) were associated with the cell cycle, DNA damage, drug metabolism, proteasome degradation, methylation, and immune response. Interaction analyses highlighted proteins related to early proteins 1,5,6 and 7 (E1, E5, E6, and E7). In terms of the two DEPs, S100 calcium binding protein A10 (S100A10/p11) and thymidine phosphorylase (TYMP) were detected in patients with LSIL, HSIL, and SCC at the protein level, consistent with their higher transcript levels in public datasets. Given the small, exploratory cohort, these findings are hypothesis-generating, and validation in a larger, balanced, independent cohort is required. In conclusion, this study identified DEPs associated with the progression of premalignant lesions to SCC that may represent candidate biomarkers and therapeutic targets warranting further investigation. Full article

This study evaluates the rapid tooling feasibility and structural significance of utilizing digital light processing (DLP)-printed alumina as a near-net-shape ceramic mold-insert preform route for replication of curved polymer optics. While conventional production tooling for precision optics demands immediate optical-grade tolerances, the fundamental mechanisms governing polymer replication close to additively manufactured ceramic interfaces remain insufficiently understood. To isolate these multi-factor processing signatures, alumina specimens incorporating concave and convex parabolic surfaces were synthesized via lithography-based ceramic manufacturing. Our design acts as a geometric control lens, ensuring that thermal shrinkage trends, slicing kinematics, and interfacial replication behaviors are clearly exposed and quantified under uniform boundary conditions. Following debinding and sintering, exploratory hot-pressing cycles were executed to evaluate gross profile transfer and surface inheritance on poly(methyl methacrylate) (PMMA) replicas. Quantitative laser scanning confocal microscopy confirmed successful gross curvature generation and revealed geometry-dependent post-sintering shrinkage trends. The convex inserts exhibited an average peak-to-valley (PV) error of 123.48 ± 3.30 µm and an RMS error of 29.76 ± 1.23 µm, whereas the concave alumina inserts showed an average PV error of 137.98 ± 5.80 µm and an RMS error of 34.68 ± 1.20 µm. The PMMA replicas also showed substantial form deviation, with an average PV error of 163.72 ± 15.64 µm and RMS error of 27.37 ± 2.03 µm. Our work presents a route for producing near-net-shape ceramic mold-insert preforms that transforms complex processing variations into a predictable, mathematically addressable roadmap. A geometry-specific CAD pre-compensation can then be performed while the remaining precision gap can be selectively closed via targeted post-polishing depending on the desired optical application tier. Full article

Efficient photocatalytic degradation of azo dyes requires coordinated control of nanostructure, surface chemical environment, and interfacial charge transport. In this work, rare-earth-modified copper-oxalate-derived CuO nanostructures (RE = Ce, Sm, Er, Tm, and Yb) were prepared through hydrothermal synthesis of a copper oxalate precursor, followed by calcination and ultrasonic-assisted RE modification. Structural, spectroscopic, optical, and electrochemical analyses show RE-associated apparent lattice perturbation, modified surface oxygen environments, stronger visible-region optical responses, higher apparent majority-carrier-density descriptors, and lower fitted interfacial charge-transfer resistance relative to pristine CuO. Among the samples, Ce-CuO exhibited the best performance, with a band gap of 1.48 eV, an apparent majority-carrier density of (1.94 ± 0.04) × 10²¹ cm⁻³, and a charge-transfer resistance of 216 Ω·cm². It achieved 91.59% methyl orange (MO) decolorization within 9 min under simulated solar irradiation, corresponding to a 23.7-fold higher apparent rate constant than pristine CuO, and retained 75.8% decolorization efficiency after eight cycles. Scavenger experiments suggested that h⁺ was the principal oxidative species under the investigated conditions, while ·OH and ·O₂⁻ also contributed to MO transformation. Overall, the results show that rare-earth modification is associated with changes in the structural, surface-chemical, optical, and interfacial electrochemical characteristics of copper-oxalate-derived CuO photocatalysts. Full article

Per- and polyfluoroalkyl substances (PFAS) such as perfluorooctanoic acid (PFOA) persist in aquatic environments due to their extremely strong C–F bonds and high environmental stability/poor biodegradability, creating an urgent demand for high-performance and scalable adsorption treatment technologies. This study reports the synthesis, characterization, and fixed-bed column adsorption performance of a dual-polymer-modified activated carbon adsorbent engineered for enhanced PFAS capture. Activated carbon (AC) was sequentially functionalized with polyethyleneimine (PEI) and poly(chlorotrifluoroethylene–co-vinylidene fluoride) (Kel–F) to form the fluorine-rich, amine-grafted composites AC–PEI–KelF and AC–PEI–KelF–PEI. Surface-area studies of the modified AC adsorbents showed a reduction in surface area of about a factor of two, possibly due to pore blockage by the polymers. Continuous-flow column breakthrough studies demonstrated dramatic improvements in perfluorooctanoic acid (PFOA) removal efficiency, with 50% maximum breakthrough time increasing from 80 min for AC to 540 min for AC–PEI–KelF and 1500 min for the AC–PEI–KelF–PEI formulation. Thomas model adsorption capacities for AC, AC–PEI–KelF and AC–PEI–KelF–PEI were, respectively, 65, 490, and 1130 mg/g. The adsorption mechanism, using selective mobile phases, was shown to be due to a combination of electrostatic and hydrophobic/fluorophilic interactions. Kinetic analysis showed that adsorption exhibited pseudo-second-order behavior, with multi-stage intraparticle diffusion. The optimized composite also exhibited strong regeneration stability, retaining 79% performance after six adsorption–desorption cycles, and displayed high selectivity for PFOA, even in the presence of structurally related competitors such as octanoic acid. The adsorption of perfluoropentanoic acid and undecafluoro-2-methyl-3-oxahexanoic acid (GenX) was also significant, and some interaction with trifluoroacetic acid was noted. Full article

Industrial wastewater containing synthetic dyes is difficult to treat because many dyes are chemically stable, highly colored, and resistant to natural degradation. In this study, a Ag₂CO₃/montmorillonite (Ag₂CO₃/MMT) composite photocatalyst was synthesized by an in situ precipitation method using acid-activated MMT as a low-cost clay support. The prepared material was characterized by XRD, FTIR, SEM, BET, and UV–Vis diffuse reflectance spectroscopy to evaluate its structural, morphological, textural, and optical properties. XRD and FTIR confirmed the formation of crystalline Ag₂CO₃ on the MMT support, while SEM analysis showed dispersed Ag₂CO₃ surface particles/deposits on the clay sheets. BET analysis indicated that the composite retained mesoporosity after Ag₂CO₃ deposition, which is beneficial for dye adsorption and diffusion. The photocatalytic performance was evaluated using methylene blue (MB) and methyl orange (MO) under visible-light irradiation. The Ag₂CO₃/MMT composite showed efficient dye decolorization, with faster degradation of cationic MB than anionic MO, mainly due to stronger electrostatic interaction between MB and the negatively charged catalyst surface. Kinetic analysis followed a pseudo-first-order model, with apparent rate constants of 0.036 min⁻¹ for MB and 0.021 min⁻¹ for MO. Operational parameters, including solution pH, irradiation time, and catalyst dosage, strongly influenced photocatalytic efficiency. Reactive species trapping experiments indicated that superoxide radicals (•O₂⁻) and photogenerated holes (h⁺) were the dominant oxidative species. The catalyst retained more than 91% activity after four cycles, indicating good recyclability under the tested conditions. These results suggest that Ag₂CO₃/MMT is a promising visible-light-responsive photocatalyst for dye-contaminated wastewater treatment. Full article

Background: As a major regulator, methyltransferase-like 3 (METTL3) catalyzes N6-methyladenosine (m⁶A) modification in mRNA. The m⁶A modifications mediated by METTL3 influence RNA splicing, nucleocytoplasmic distribution, stability, and other functions, thereby playing a vital and indispensable role in genetic regulatory network. Although several studies have shown its critical role in mRNA fate, the global pattern of mRNA methylation alteration driven by METTL3 remain unclear. Methods: Here, a HEK293T cell line with METTL3 depletion was constructed, and RNA sequencing (RNA-seq) and methylated RNA Immunoprecipitation Sequencing (MeRIP-seq) were implemented. Additionally, quantitative Reverse Transcription PCR (qRT-PCR) technology was used to confirm some of the differentially expressed genes. Result: The mRNA methylation alteration landscape was clarified and the regions altered by m⁶A modification due to METTL3 deletion that was annotated and characterized, with 5763 hypomethylated/269 hypermethylated genes after METTL3 silence. Several methylation-related innate anti-infection immune genes, including MYD88, RIG-1, CYLD and IRF9, were exposed through comprehensive analysis to MeRIP-seq and RNA-seq data, and these genes were principally enriched in pathogen infection and innate immune response pathways such as Shigellosis, Yersinia infection, and the HIV-1 viral life cycle. Conclusion: Our study discovered that the METTL3 association with differentially expressed genes, suggested that METTL3 and the genes it regulates might serve as targets for defense against infection. Full article

S-adenosyl-L-homocysteine hydrolase (SAHH) is an evolutionarily conserved enzyme present in eukaryotes, bacteria, and archaea. As the rate-limiting enzyme in the methionine cycle, it catalyzes the reversible hydrolysis of S-adenosyl-L-homocysteine (SAH) to adenosine and homocysteine, thereby modulating the S-adenosylmethionine/SAH ratio and cellular methylation potential. Dysregulation of SAHH activity is causally linked to cancer, cardiovascular disorders, and neurodegenerative conditions. This review systematically examines the biological distribution, catalytic mechanisms, structural architecture, and regulation of SAHH across diverse species. We highlight lineage-specific adaptations—including C-terminal truncation, a 40-residue substrate-binding-domain insertion, and a His-Phe molecular gate—that fine-tune substrate preference, cofactor affinity, and thermostability, with metal ions and NAD⁺ serving as key modulators of activity and conformational dynamics. These variations exemplify an evolutionary trade-off between catalytic efficiency and structural rigidity, particularly pronounced in archaeal and thermophilic orthologs. Collectively, these insights underpin the enzyme’s multifaceted translational value: SAHH serves as a therapeutic target for diverse diseases (e.g., cancer, viral infections, tuberculosis), a source of diagnostic/prognostic biomarkers (e.g., plasma homocysteine and SAH/SAM ratio), and a versatile biocatalyst for synthesizing pharmaceutical-grade adenosine and its derivatives. By integrating mechanistic, structural, and evolutionary perspectives, this review establishes a unified framework that explains these functional adaptations and their translational implications. This framework guides the rational development of SAHH-targeted inhibitors, diagnostic tools, and engineered biocatalysts, with broad applications in precision medicine and biotechnology. Full article