Search Results (7,026)

Physical integration between endosymbiotic algae and host mitochondria is a recurring feature across photosynthetic symbioses, yet the structural nature of this association has remained unresolved. In the ciliate Paramecium bursaria, each endosymbiotic Chlorella cell is enclosed by a perialgal vacuole (PV) membrane consistently surrounded by host mitochondria, suggesting a conserved architecture for metabolic interaction. Although transmission electron microscopy has shown close membrane apposition, it has remained unclear whether this reflects incidental proximity or a reinforced adhesion. Here, we provide direct evidence that the PV membrane and host mitochondrial membrane form a stable physical association. Using discontinuous Percoll centrifugation, we isolated intact units in which Chlorella and mitochondria co-sedimented, indicating that their association withstands mechanical disruption. By fluorescently labeling the PV and mitochondrial membranes with BODIPY FL C₅-ceramide (BC₅C), together with a mitochondria-specific monoclonal antibody and DAPI, we visualized the PV membrane under light microscopy and demonstrated that the mitochondrial–PV membrane complex persists after homogenization and centrifugation. As expected from the membrane-insertion behavior of BC₅C, this fluorescent labeling revealed that the PV–mitochondrial membrane association is structurally reinforced rather than incidental, providing a mechanistic framework for understanding how Chlorella cells are stably positioned beneath the host cortex. Full article

This study focused on elucidating the effects of chitosan (Ch), hyaluronic acid (HA), and titanium dioxide nanoparticles (nano-TiO₂) on the physicochemical characteristics of a model bacterial membrane (layer) composed of the phospholipid DPPG (1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt). The membrane was prepared on mica using the Langmuir–Blodgett (LB) technique from an aqueous subphase containing Ch, HA and/or TiO₂. Its surface properties were subsequently characterized by optical profilometry and surface free energy estimation. The nanoscale topography of the DPPG layer provided a biomimetic platform that reflects the organization of bacterial membranes, enabling a precise evaluation of how external agents, such as Ch, HA, and nano-TiO₂, modify the surface’s structural and energetic properties. The results showed that the LB films exhibit mildly heterogeneous topography, which can be attributed to lipid domains with distinct molecular packing densities. Depending on the type of biopolymer employed with TiO₂, distinct topographic architectures of the DPPG monolayers were obtained. Furthermore, the presence of nano-TiO₂ was clearly manifested as a topographic irregularity, while the analysis of hydrophilic–hydrophobic properties revealed a structurally perturbed lipid film. The results provide detailed insight into how these specific molecules (Ch, HA, nano-TiO₂) interact at the molecular level with model bacterial membranes, offering a comprehensive picture of cell–microenvironment interactions. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells when the spike receptor-binding domain (RBD) engages angiotensin-converting enzyme 2 (ACE2). Cannabinoid scaffolds have recently been reported to bind S1/RBD, block spike-mediated membrane fusion, and modulate host inflammatory pathways, making them attractive candidates for entry inhibition. Here, we applied an integrated computational pipeline to prioritize cannabis-derived compounds as interfacial blockers of the RBD–ACE2 complex across variants. Eleven phytocannabinoids were docked into the wild-type (WT) RBD–ACE2 interface, identifying three cavities, with ligands preferentially occupying pocket 1. Complexes were subjected to triplicate 200 ns all-atom molecular dynamics (MD) simulations for WT, Delta, and Omicron BA.1 RBD–ACE2. Binding energetics were quantified using molecular mechanics/generalized Born surface area (MM/GBSA) and solvated interaction energy (SIE), and per-residue contributions were analyzed together with solvent-accessible surface area (SASA) and residue interaction networks. Among all compounds, cannabidiol (CBD) and cannabinol (CBN) were the only ligands that remained stably bound in pocket 1 for all variants. CBN showed the most favorable ligand–complex binding in WT, whereas CBD preserved favorable binding in Omicron BA.1 despite reduced interface burial, indicating that van der Waals/electrostatic complementarity and solvation, rather than surface coverage alone, govern affinity. Both ligands weakened modeled RBD–ACE2 binding by perturbing hot-spot residues centered on Y505 or N501Y in RBD and E37, A387, and R393 in ACE2. Overall, our results highlight CBD and CBN as tractable, variant-spanning interface disruptors and illustrate how MD-based free-energy calculations can support computational drug discovery against evolving viral protein–protein interfaces. Full article

Concentrated natural rubber skim latex is a sustainable, value-added product derived from natural rubber latex processing, offering high rubber content, fine particle size, and shorter polymer chains compared to pure latex, making it suitable for diverse industrial applications. This study employed an environmentally friendly ultrafiltration method using composite membranes composed of polyvinylidene fluoride (PVDF), titanium dioxide (TiO₂), and polyvinylpyrrolidone (PVP) to concentrate skim latex without hazardous chemicals. The process generated two fractions: concentrated skim latex and skim serum. Membrane performance and fouling behavior were evaluated using FESEM-EDX and FTIR. Post-filtration analysis revealed significant latex particle deposition on the membrane surface, with elemental mapping confirming the presence of organic and inorganic residues. FTIR spectra indicated interaction between latex components and membrane functional groups, though the membrane’s structural integrity remained intact. Sodium dodecyl sulfate (SDS) was assessed as a cleaning agent and demonstrated the effective partial restoration of membrane performance, as confirmed by flux recovery (PVDF-PVP-TiO₂ membrane recovered to a slightly higher flux of 7.35 L/m²h). These results highlight the membrane’s durability, fouling characteristics, and cleaning potential, supporting its reusability in latex processing. This study contributes to the development of sustainable separation technologies in the rubber industry, promoting circular economy and zero-discharge practices. Full article

Fuel cell technologies are increasingly investigated as alternatives to conventional auxiliary diesel generators in order to enhance shipboard energy efficiency and reduce greenhouse gas emissions. This study presents a unified and uncertainty-driven system-level assessment of solid oxide fuel cell (SOFC) and proton exchange membrane fuel cell (PEMFC) systems operating as auxiliary power sources on a 200 m bulk carrier. Both technologies are evaluated under identical vessel characteristics, operating profiles, auxiliary load levels (360–600 kW), and cost assumptions, and are benchmarked directly against a conventional three–diesel-generator configuration. A modular numerical framework is developed to model propulsion–auxiliary interactions for ship speeds between 10 and 14 knots. SOFC systems are assessed using grey, bio-derived, and green natural gas pathways, while PEMFC systems are examined under grey, blue, and green hydrogen supply routes. Performance indicators include annual fuel consumption, carbon dioxide (CO₂) emission reduction, net present value (NPV), internal rate of return (IRR), payback period (PBP), and marginal abatement cost (MAC). Economic uncertainty is explicitly embedded in the framework through Monte Carlo simulation, where fuel prices (±20%) and capital costs are sampled across defined ranges, generating probabilistic distributions rather than single deterministic estimates. This uncertainty-centred approach enables assessment of robustness, downside risk, and probability of profitability. Results show that replacing a single operating 600 kW diesel generator with fuel cell systems reduces auxiliary fuel energy demand by 25–35% for SOFC and approximately 15–25% for PEMFC relative to the diesel benchmark. Annual CO₂ reductions range from 1.1 to 1.3 kt for SOFC systems and 1.8–2.8 kt for PEMFC configurations. Under grey fuel pathways, median NPVs reach approximately 2–4.5 M$ for SOFC and 9–17 M$ for PEMFC as load increases, with IRRs exceeding 15% and 30%, respectively. Transitional pathways exhibit narrower margins, while renewable pathways remain more sensitive to fuel price variability. The findings demonstrate that fuel pathway cost dominates lifecycle outcomes under uncertainty and that hydrogen-based PEMFC systems exhibit the strongest economic resilience within the examined market ranges. The framework provides structured, uncertainty-aware decision support and establishes a foundation for integration into model-based systems engineering (MBSE) environments for early stage ship energy system design. Full article

Gamma-tocotrienol (GT3) is one of the constituents of vitamin E that demonstrated significant radioprotective efficacy in murine and nonhuman primate (NHP) models. Considering the antioxidant activity of GT3 and its role in terminating lipid peroxidation, we hypothesize that mechanism of radioprotective effect of GT3 may involve the inhibition of irradiation-induced ferroptosis—a form of regulated cell death characterized by excessive, iron-dependent, peroxidation of lipids in cellular membranes. To test this hypothesis, the metabolomic and proteomic data from serum samples of GT3- or vehicle-treated NHPs exposed to 12 Gy (partial- or total-body) radiation was analyzed with focus on lipid peroxidation markers and proteins involved in iron metabolism. Four secondary lipid peroxidation products were identified including 4-oxo-2-nonenal (4-ONE), 4-hydroperoxy-2-nonenal (4-HPNE), 3,4-epoxynonanal (3,4-ENA), and trans-4,5-epoxy-(2E)-decenal (4,5-EDE). In vehicle-treated animals, their concentrations increased significantly as soon as 4 h after irradiation and then gradually declined. GT3 treatment mitigated this radiation-induced increase. In addition to lipid peroxidation products, similar patterns of change were observed for several polyunsaturated, monounsaturated, and saturated fatty acids as well as amino acids such as lysine and its derivatives. Taken together, these metabolomic changes suggest that irradiation induces cellular membrane damage through enhanced lipid peroxidation, while GT3 exerts a protective effect against this process. In addition, GT3 increased serum levels of haptoglobin and hemopexin—two plasma scavenger proteins that play complementary protective roles in iron and heme homeostasis. Although the present study does not conclusively demonstrate that GT3 mediates radioprotection via inhibition of ferroptosis, the data suggest that GT3 limits membrane damage and reduces susceptibility to ferroptosis by enhancing iron and heme scavenging. Further investigation into the interaction between GT3 and key components of ferroptosis following exposure to ionizing radiation is therefore warranted. Full article

Peptaibols, predominantly secreted by Trichoderma species, are a class of linear peptides composed of five to twenty amino acid residues, synthesized non-ribosomally and enriched with α-amino isobutyric acid. These unique peptides appear to be highly effective in mediating the interactions between Trichoderma and plant pathogenic fungi. In this study, Ultra-Performance Liquid Chromatography–Quadrupole Time-Of-Flight Mass Spectrometry/Mass Spectrometry (UPLC-QTOF-MS/MS) technology was used to detect peptaibols profiles of Trichoderma strains during their interactions with the pathogen Fusarium graminearum. MS investigations of crude extracts derived from in vitro confrontations of Trichoderma atroviride T23 and its genetically modified counterparts, dual-culture assays of Mlae1, Mvel1, OElae1, and OEvel1 with F. graminearum were performed to shed light on the regulatory role of the velvet complex composed of LAE1&VEL1 in the synthesis of peptaibols during the microbial interaction. These results revealed intriguing variations in the total peptaibols produced during the interactions, as well as some differences in the specific peptaibol profiles between the confrontation and control tests. The overexpression strains, OElae1 and OEvel1, distinguished themselves by their proficiency in inducing long-residue peptaibols synthesis, attaining an impressive biocontrol index of up to 76%. The crude extracts containing peptaibols of OElae1 and OEvel1 demonstrated a capability to enhance cell membrane permeability and decrease DON toxin production in F. graminearum, and the crude extracts of OElae1 strains exhibited more effectiveness in reducing DON toxin production. In conclusion, the interaction with F. graminearum significantly impacted the peptaibol production in the examined Trichoderma strain, emphasizing the intricate interplay and reciprocal influence of genetic factors and environmental stimuli. Full article

Mitochondrial dysfunction plays a central role in the pathogenesis of bronchopulmonary dysplasia (BPD). Solute carrier family 25 member 28 (SLC25A28) is an iron transporter located in the inner mitochondrial membrane. In this study, we aimed to explore the role and underlying molecular mechanisms of SLC25A28 in BPD. Hyperoxia (85% O₂) was used to establish a neonatal murine model of BPD, and mouse lung epithelial cells (MLE-12 cells) were used in vitro. SLC25A28 expression and activity were downregulated under hyperoxic conditions, both in vivo and in vitro. SLC25A28 overexpression restored hyperoxia-induced mitochondrial oxidative phosphorylation (OXPHOS) dysfunction, and further enhanced the proportion of Ki67-positive cells by 37% (p < 0.05) and increased migration by 33% (p < 0.01) in MLE-12 cells. In contrast, SLC25A28 knockdown exacerbated these impairments in MLE-12 cells, with reduced the proportion of Ki67 positive cells by 71% (p < 0.01) and a 35% reduction in the migration rate. SLC25A28 was also knocked down in vivo, which further aggravated alveolar simplification in BPD mice. Furthermore, the mitochondrial-targeted peptide SS-31 could potentially interact with SLC25A28 and preserve its protein abundance. SS-31 administration mitigated hyperoxia-induced alveolar simplification, with the radical alveolar count (RAC) increasing by 28% (p < 0.05) and the mean linear intercept (MLI) decreasing by 20% (p < 0.001). In summary, this study revealed that SLC25A28 ameliorated hyperoxic lung injury by improving mitochondrial OXPHOS in alveolar epithelial cells, suggesting that it may serve as a potential therapeutic target for BPD. Full article

As the demand for sustainable and bio-based alternatives to petroleum-derived membranes grows, polysaccharides have emerged as promising candidates. In this study, we fabricated free-standing membranes from konjac glucomannan (KGM), a neutral polysaccharide, using a simple base-induced insolubilization process. Fourier transform infrared spectroscopy revealed that the deacetylation of KGM chains promotes extensive intermolecular hydrogen bonding, creating a robust and stable three-dimensional network without the need for chemical cross-linkers. The resulting KGM free-standing membranes exhibited excellent mechanical properties, characterized by high tensile strength in the dry state and remarkable flexibility when hydrated. Furthermore, the membranes demonstrated superior chemical resistance to organic solvents such as acetone and n-hexane. Transport studies showed that the membranes possess a highly dense structure with no detectable pressure-driven pure-water permeation up to 0.25 MPa. Solute permeation experiments using eight model molecules (molecular weight = 144–14,600 Da) indicated that transport behavior is consistent with diffusion through a hydrated polymer network. The effective diffusion coefficient D_eff showed a strong correlation with molecular weight M, following the relationship D_eff ∝ M^−1.7. Furthermore, the permeation behavior remained stable across a wide pH range (2–12), and, within the investigated range of monovalent solutes, D_eff was insensitive to solute charge, indicating that mass transport is dominated by size-based diffusion rather than electrostatic interactions. These findings suggest that KGM free-standing membranes enable reliable molecular fractionation based on size-dependent diffusion within a stable, neutral matrix, offering significant potential for sustainable separation technologies and biomedical applications. Full article

Gold nanoparticles (AuNPs) have been extensively studied in cancer treatment research since they have special physicochemical characteristics such as facile surface functionalization with various chemical groups, low toxicity, favorable biocompatibility, and the ability to passively accumulate in tumors through the enhanced permeability and retention (EPR) effect. Prostate cancer cells exhibit an overexpression of the Prostate-Specific Membrane Antigen (PSMA), which therefore represents an ideal candidate for the development of nanoplatforms targeting PSMA overexpressed on these cells. Lutetium-177 (¹⁷⁷Lu) is a β-particle emitter with a half-life of 6.7 days. This radionuclide is very promising for the development of theranostic platforms as it emits β⁻ particles, which are suitable for therapy, and γ-photons, capable of SPECT imaging. The combination of ¹⁷⁷Lu with AuNPs functionalized with PSMA for targeted delivery offers a promising tool for both diagnosis and therapy of prostate cancer. In this study, we focused on the synthesis and in vitro evaluation of PSMA-targeted AuNPs radiolabeled with ¹⁷⁷Lu. The AuNPs were functionalized with the TADOTAGA chelator, which enables effective radiolabeling with the radiometal, as well as with a PSMA molecule, which comprises the PSMA targeting moiety (vehicle) of the nanoconstruct. Radiolabeling of the functionalized AuNPs with ¹⁷⁷Lu was fast and robust. Subsequent studies focused on the in vitro stability and cellular interaction with two prostate cancer cell lines with different PSMA expression levels, in both 2D and 3D cell cultures, to assess effective targeting. Results indicate that radiolabeled AuNPs exhibit selective interaction with PSMA-expressing cells and present a stronger in vitro cytotoxic effect when functionalized with the PSMA molecule, confirming their potential as theranostic agents and warranting further investigation in LNCaP tumor-bearing mice. Full article

During development, tissues or organs are organized into distinct cell populations that do not intermix. The precise spatiotemporal arrangement of these populations establishes tissue boundaries and ensures proper morphogenesis. Signaling between membrane-bound Eph receptors and their ephrin ligands underlies the formation of multiple developmental boundaries, including those between germ layers, rhombomeres, and eye fields. Moreover, accumulating evidence indicates that actomyosin contractility serves as an important mechanical driver of Eph/ephrin-cell segregation and boundary formation. However, the mechanism by which Eph/ephrin signaling regulates actomyosin contractility have received relatively limited attention in previous reviews, particularly in the context of boundary sharpening. In this review, we focus on the interplay between Eph/ephrin signaling and actomyosin contractility and discuss how this interaction contributes to cell segregation and boundary formation. Full article

Hybrid desalination systems that combine osmotic and thermal driving forces offer a promising route to improve water recovery and energy efficiency for high-salinity feedwaters where conventional processes face limitations. This study presents a comprehensive mathematical modeling framework and performance analysis of a hybrid forward osmosis–membrane distillation (FO-MD) system for seawater desalination. The novel contributions include: (1) a coupled heat, mass, and solute transport model that explicitly accounts for concentration polarization, temperature polarization, reverse salt flux, and their dynamic interactions through the draw solution loop; (2) a quantitative assessment of the synergistic regeneration effect, showing how MD maintains draw solution concentration and stabilizes FO performance over time; (3) systematic evaluation of parameter sensitivity to polarization effects; and (4) comparative energy analysis quantifying specific energy consumption relative to standalone processes. Model predictions were validated against published experimental data, showing good agreement for both FO and MD fluxes (R² > 0.94). The MD flux increased from approximately 2–3 LMH at 30 °C to 17 LMH at 50 °C, confirming vapor pressure enhancement. FO water flux increased significantly with draw solution concentration from 0.2 to 1.1 M due to higher osmotic pressure differences. Time-dependent simulations of the integrated FO-MD system showed that MD regeneration reduces draw solution dilution by 60% compared to standalone FO, maintaining FO flux approximately 43% higher after 6 h of operation. Sensitivity analysis revealed that FO predictions are moderately sensitive to mass transfer coefficients (6–9% flux change for 20% parameter variation), while MD shows lower sensitivity to heat transfer coefficients (3–5%). Energy analysis indicates that FO-MD hybridization reduces thermal energy consumption by 15–40% compared to standalone MD, with specific energy consumption of 382 kWh/m³ (40.2 kWh/m³ primary energy equivalent) when using low-grade heat. The obtained results demonstrate that FO-MD hybridization enhances water recovery and operational stability compared to standalone processes, supporting its potential for energy-efficient desalination of high-salinity brines and industrial wastewaters where low-grade heat is available. Full article

Cyclotides are exceptionally stable plant peptides whose biological activity is widely attributed to interactions with lipid membranes, yet the molecular mechanisms underlying these interactions remain incompletely resolved. Here, we employ microsecond-scale (1 μs) all-atom molecular dynamics simulations to investigate the membrane association of the cyclotide kalata B1 with phospholipid bilayers of distinct headgroup composition, including POPC, POPE, and POPG. This extended timescale enables full bilayer equilibration and allows observation of slower peptide-induced membrane responses that are not accessible in shorter simulations. Across all systems, kalata B1 rapidly adsorbs to the membrane surface and remains predominantly surface-associated throughout the simulations, while the cyclic cystine knot motif remains structurally intact, confirming the exceptional robustness of the cyclotide fold during membrane engagement. Lipid-dependent differences arise primarily from variations in peptide orientation, conformational flexibility, and interfacial dynamics rather than deep bilayer insertion or pore formation. Zwitterionic POPC membranes favor compact, upright peptide configurations, whereas POPE and POPG bilayers promote enhanced lateral spreading and dynamic reorganization driven by hydrogen bonding and electrostatic interactions, respectively. Leaflet-resolved analyses of lipid contacts, membrane thickness, and area per lipid reveal localized, asymmetric perturbations confined to the peptide-exposed leaflet, with no evidence of sustained bilayer thinning or global destabilization. Together, these results support an interfacial, headgroup-dependent mechanism of cyclotide membrane activity and reconcile previous experimental observations. This work provides molecular-level insight into lipid selectivity and early-stage cyclotide–membrane interactions that may inform future design of cyclotide-based bioactive agents. Full article

The conserved protein SetDB1 has been identified in various vertebrate and invertebrate groups. It plays key roles in vital processes such as germline and nervous system development, immune response, tumorigenesis, cell cycle progression, and others. SetDB1 is initially characterized as an enzyme that methylates lysine 9 on histone H3, leading to gene silencing, which is traditionally considered its primary function. However, SetDB1 also targets about a dozen nuclear, cytoplasmic, and membrane proteins as substrates. Moreover, some functions of SetDB1 do not require methyltransferase activity. Due to its SUMO-interacting motif, Tudor domain, and methyl-binding domains, SetDB1 interacts with a wide range of complexes that regulate protein stability and activity, signal transduction pathways, and chromatin spatial organization. In this review, we aim to expand the classical view of SetDB1 as solely a histone methyltransferase and to highlight the broader diversity of its functions. Full article

Sulfamethoxazole (SMX) is one of the most frequently detected antibiotics in aquatic environments and is difficult to remove by conventional biological treatment because of its persistence, potential toxicity to microbial communities, and associated risk of antibiotic resistance selection. Aerobic granular sludge membrane bioreactors (AGMBRs), which combine the compact and stratified structure of aerobic granular sludge with membrane-based solid–liquid separation, have emerged as a promising platform for SMX-contaminated wastewater treatment because they provide high biomass retention, decoupled sludge retention time (SRT) and hydraulic retention time (HRT), and stable effluent quality. This review systematically summarizes recent advances in AGMBRs for SMX removal, with emphasis on how operating parameters (e.g., dissolved oxygen, hydraulic retention time, organic loading rate, C/N ratio, and sludge retention time) and membrane-related factors (e.g., membrane flux, aeration-induced shear, membrane type, and pore size) affect treatment performance and process stability. The main SMX attenuation pathways in AGMBRs are discussed from three perspectives: sorption and partitioning within granules and extracellular polymeric substances (EPSs), microbial biodegradation and co-metabolism, and membrane retention that prolongs effective contact time and shapes microbial ecology. Particular attention is given to the dual role of EPS and soluble microbial products (SMPs), which contribute to granule stability and SMX tolerance but also accelerate membrane fouling through cake-layer formation, pore blocking, and transmembrane pressure increase. Current challenges include incomplete understanding of transformation products, ARG- and MGE-related risks, long-term fouling–biodegradation interactions, and the lack of pilot-scale validation. Future research should therefore focus on mechanism clarification, integrated control of removal and fouling, energy-efficient operation, and scale-up of AGMBRs for practical antibiotic wastewater treatment. Full article