Search Results (857)

The morphology and micromorphology of Aristotle’s lantern, the feeding apparatus of Scaphechinus mirabilis, were examined using light microscopy, scanning electron microscopy, and X-ray microscopy. S. mirabilis had food grooves on the ventral side, which extended to the mouth. Aristotle’s lantern was a star-shaped calcareous skeletal structure attached to the test by the apophysis and consisted of pyramids, joints, and teeth. The pyramid consisted of two demi-pyramids, an epiphysis, and a bump, whereas the joint located between the pyramids consisted of the interpyramidal ligament and rotula. The tooth was an elongated trapezoid with one pointed end (3.98 × 0.97 × 0.38 mm) and was divided into an embedded part and a projection part. The embedded part was connected to the dental ligament and dental promoter muscle, whereas the projection part was divided into a basal projection part covered by the peridental membrane and an apical projection part protruding beyond the tooth slide. The tooth exhibited a calcareous lamellar structure composed of 15–20 layers, and its distal end was worn. These findings indicate that the morphology of the tooth is specialized for internal crushing of sediment and food particles within the Aristotle’s lantern. Full article

Introduction: Catheter-associated urinary tract infections (CAUTIs) caused by multidrug-resistant (MDR) uropathogens pose a management challenge due to bacterial biofilm formation and crystalline encrustation, especially those associated with Proteus mirabilis, which result in persistent infections and catheter obstructions. Current catheter surface coatings against CAUTIs target either the initial stages or later phases of such pathologies separately. Aim: We report the design and characterization of a novel polyfunctional coating comprised of polydopamine (PDA), genipin-crosslinked chitosan (GCS), and ZnO nanoparticles capable of blocking bacterial attachment, biofilm formation, and mineral encrustation. Methods: PDA-coated silicon surfaces were functionalized with genipin-crosslinked GCS/ZnO nanocomposites and studied by means of TEM, XRD, FTIR, SEM, AFM, water contact angle measurements, and zinc ion release tests. Antibacterial, antibiofilm, anti-encrustation, and hemocompatibility activities were then assessed. Results: ZnO nanoparticles were spherical, with an average particle size of 34.6 ± 8.2 nm and a highly crystalline hexagonal wurtzite structure. Coatings containing ZnO nanoparticles retained hydrophilic surface properties and released Zn²⁺ ions steadily. The G5 coating (containing 0.2% ZnO) demonstrated an ability to decrease bacterial adherence by >4 log₁₀ CFU, lower biofilm biomass by 80–90% (p < 0.001), prevent mineral deposition by 67–70% caused by Proteus mirabilis, and keep catheter patency for 14 days. Hemolysis was within the ISO 10993-4 acceptance criteria. Conclusions: A rationally designed combination of PDA, genipin-crosslinked GCS, and ZnO nanoparticles provided a multifunctional coating with potent antibacterial, antibiofilm, anti-encrustation, and initial hemocompatibility activity, serving as a proof-of-concept platform for further cytotoxicity assessment, mechanical durability studies, and preclinical evaluations prior to clinical implementation. Full article

The effect of Ti content on the microstructure and mechanical properties of 1Cr10Co6MoVNbN steel was systematically investigated by comparing a low-Ti steel (LTS, 0.0066 wt.%) with a high-Ti steel (HTS, 0.02 wt.%). Increasing the Ti content was found to markedly alter the precipitate distribution and, consequently, the creep and high-temperature tensile behavior. In HTS, the higher Ti level promoted the preferential formation of (Ti,Nb)N inclusions during solidification; EDS analyses indicated that the matrix of HTS was substantially depleted of Nb, N, Mo, and V relative to LTS, consistent with this preferential nitride formation. In the tempered state, HTS exhibited larger NbC particles that were frequently attached to (Ti,Nb)N inclusions, whereas LTS contained finer, more uniformly dispersed NbC and abundant needle-like Cr₂N precipitates within martensitic laths. These microstructural differences correlated with a substantially higher 100 h creep strain in HTS compared with LTS at 550 °C and 325 MPa, and with a 550 °C tensile strength in HTS that fell below the aerospace standard requirement. Post-creep examination further revealed void formation around (Ti,Nb)N inclusions in HTS, suggesting that these inclusions act as stress concentrators that reduce the effective load-bearing area during creep. The results indicate that strict control of Ti content is essential in Nb–N-strengthened martensitic steels to avoid excessive (Ti,Nb)N formation and the associated degradation of high-temperature mechanical performance. Full article

During coal beneficiation in a gas–solid fluidized bed, coarse feed particles act as moving intruders whose size and shape can reorganize the local gas–solid flow field. This study combines particle-surface differential-pressure measurements, synchronized visual observation, pressure-signal analysis, and Eulerian–Eulerian CFD to distinguish the disturbance caused by the feed particle from the background fluctuation of the dense medium. Unlike studies that characterize only the global bed pressure drop, the present work resolves the pressure response on the upper and lower surfaces of individual 13–50 mm feed particles and links it to bubble attachment, bypassing, and medium-particle recirculation. Within a fluidization-number range of 1.0–1.6, the disturbance intensified with feed-particle size: the 50 mm particle produced the largest upper–lower pressure difference and pressure-drop fluctuations exceeding 100 Pa. Particle shape also altered the local flow topology; the flat lower face of the block-shaped particle promoted a persistent gas cushion, localized pressure concentration, and medium recirculation; whereas, the spherical particle generated a comparatively symmetric disturbance. Synchronized images confirmed the transition from intermittent small bubbles near minimum fluidization to bubble coalescence and vigorous recirculation at higher gas velocities. At N = 1.2, the CFD results reproduced the experimental size and shape rankings, with case-by-case relative errors of 4.7–7.0% and a mean absolute relative error of 5.5%. Coherence analysis further showed that the influence of a large particle decayed with distance and produced a stepwise axial distribution of local flow states. These results provide a particle-scale basis for controlling feed-induced disturbances in gas–solid fluidized-bed separation. Full article

Maraviroc (MVC), a CCR5 antagonist, has been proposed as a potential antiviral agent against SARS-CoV-2; however, its mechanism of action across viral variants remains unclear. Here, we evaluated the antiviral activity of MVC against SARS-CoV-2 wild-type (WT) and Omicron BA.1 variants using single-round infectious particles (SRIPs), virus-like particles (VLPs), and cell-based assays, with a focus on its impact on viral entry and Mpro function. MVC potently inhibited infection of both WT and BA.1 SRIPs in Vero E6 cells, exhibiting EC₅₀ values of 0.0065 μM and 0.016 μM, respectively. Time-of-addition assays revealed that MVC primarily targets the early phase of infection, with the strongest inhibition observed at the viral entry stage, while moderate effects were detected during attachment and post-entry stages. Fluorescence-labeled VLP imaging demonstrated distinct entry pathways, with WT predominantly entering via plasma membrane fusion and BA.1 via endocytosis, independent of cell type. MVC altered WT-VLP trafficking by promoting internalization and lysosomal localization, whereas it had minimal impact on BA.1 internalization. In spike-mediated cell–cell fusion assays, MVC preferentially inhibited WT spike-driven syncytium formation but showed limited effects on BA.1 or BA.4 fusion, while more effectively reducing Omicron spike-mediated binding. At the post-entry stage, MVC inhibited SARS-CoV-2 main protease (Mpro) activity, with BA.1 Mpro (P132H) exhibiting greater sensitivity (IC₅₀ = 0.496 µM) than WT (1.869 µM). Collectively, these findings demonstrate that MVC exerts variant-dependent antiviral effects by targeting viral entry, modulating trafficking pathways, and inhibiting Mpro activity. This study highlights MVC as a multi-stage inhibitor with differential efficacy against SARS-CoV-2 variants, providing insights into its potential therapeutic application. Full article

Self-assembled artificial nanostructures, such as DNA origami, have attracted interest as templates for the placement of inorganic materials because their design enables the incorporation of binding sites for attaching nanocomponents with nanometer-scale precision. In this work, we introduce a lithographically defined window-array substrate as an addressable platform for dark-field spectroscopic studies of individual DNA-origami-templated metallic nanostructures. The pattern was designed using the Nanometer Pattern Generation System (NPGS) software and written by electron beam lithography (EBL) on a SiO_x/Si substrate. The role of the EBL pattern is to provide spatially separated measurement sites that facilitate the localization, selection, and optical interrogation of single-particle and dimer configurations. Metallic nanostructures created by the DNA origami technique, with programmable placement of spherical gold nanoparticles (Au NPs), are used here. The nanostructures are rectangular, measuring 70 nm × 90 nm, with an Au NP attached at one corner or at two opposite corners. These seed NPs are later enlarged by controlled coalescence via electroless silver deposition. Localized surface plasmon resonance (LSPR) studies by dark-field microscopy (DFM) are presented as a proof-of-concept application for evaluating the scattering response of individual silver-metalized nanoparticles and dimers. Full article

Nano- and microplastics (NMPs) are now widely detected across agroecosystems and can act as physiological stressors in plants. Exposure occurs through contaminated soil, irrigation water, or airborne deposition, bringing particles into direct contact with roots and above-ground tissues. Reported entry routes include apoplastic transport, cracks formed at lateral root emergence, leaf stomata, and endocytosis once particles have crossed the cell wall. Once internalized, particles may translocate through the xylem and, in some cases, the phloem, accumulating in roots, stems, and leaves depending on particle size, surface charge, and plant structural characteristics. NMPs have been associated with oxidative stress, disrupted photosynthesis, and altered metabolic pathways. Detecting NMPs within heterogeneous, hydrated plant tissues remains challenging, as particles often show low contrast against biological structures and can be mistaken for cellular components. This review examines how microscopy techniques reveal NMPs size, surface attachment, tissue distribution, and cellular-level interactions, while noting that these approaches primarily provide morphological or localization information rather than confirming polymer identity. Complementary spectroscopic and mass-based analytical methods are discussed for their role in chemical confirmation and quantification. This review supports informed selection among imaging, spectroscopic, and quantitative techniques for studying plant–plastic interactions, while highlighting current analytical challenges facing the field. Full article

To address the problem of the short service life of relay injection molds caused by erosion of high-temperature glass fibers, AlCrN coatings were deposited on the surface of ELMAX mold steel using multi-arc ion plating technology. The surface morphology, cross-sectional morphology, and elemental composition of the coatings were analyzed using scanning electron microscopy (SEM) and the attached energy-dispersive X-ray spectroscopy (EDS). The phase structure was characterized by X-ray diffraction (XRD). The surface hardness, film–substrate adhesion strength, and friction and wear performance were tested using a nanoindenter, a scratch tester, and a friction and wear tester, respectively. The effects of duty cycle, arc current, and negative bias voltage on the coating microstructure, hardness, adhesion strength, and friction and wear performance were systematically investigated. Increasing the duty cycle increases surface particles and pits but improves coating density; increasing the arc current increases coating thickness but coarsens particles; increasing the negative bias voltage refines particles but increases pits. Through a three-factor, three-level orthogonal experiment and a multi-index equal-weight weighting method, with hardness, adhesion strength, and friction coefficient as comprehensive evaluation objectives, the optimal process parameters were determined as a duty cycle of 70%, an arc current of 60 A, and a negative bias voltage of 110 V. The optimized coating achieved a hardness of 36.04 GPa (399% higher than that of the uncoated substrate), an adhesion strength of 143.87 N, and a friction coefficient of 0.422. In production cycle tests, the coated mold exhibited an average service life of 128,070 cycles, which is 277% higher than that of the uncoated mold (33,985 cycles). The surface of the coated mold showed only slight scratches, while the uncoated mold exhibited severe glass-fiber plowing grooves. This study provides a process optimization and verification solution for extending the service life of injection molds. Full article

Solar stills are considered an effective solution to produce fresh drinking water from saline water. Solar stills utilize solar energy, which is available in abundant quantity for long periods across Middle Eastern countries like Oman. In this study, two single-slope passive solar stills are fabricated with two configurations: a Conventional Solar Still (CSS) and a Modified Solar Still (MSS). The CSS is the basic model, whereas the MSS is a model obtained by incorporating copper tubes that are filled with phase change material (PCM) combined with nano copper oxide particles, which are attached inside the basin. The objective of this study is to compare the performance of the two systems from energy, exergy, and economical aspects. The solar stills were fabricated according to the geometrical conditions of the city Nizwa, Oman, and the standards for the fabrication of each solar still component. The highlights of this research are comparing the performance of the CSS and MSS under the prevailing atmospheric conditions of the city Nizwa, Oman, and investigating the effects of the nano materials and phase change materials used in the MSS on its performance. The results of the study reveal certain important facts; for example, higher thermal conductivity of the copper tubes increases the heat transfer and evaporation of saline water inside the basin. The freshwater production in the MSS was higher than in the CSS, with an average difference of about 79.75%. This difference in freshwater production is due to the accumulated heat storage and release of heat from the PCM material combined with nanoparticles during reduced solar radiation. The nanoparticles contributed to an increase in the heat transfer rate of the PCM. The presence of copper tubes filled with nano-PCM in the MSS influences and increases both energy and exergy efficiencies to around 30 to 35% and 1 to 1.5% compared to those in the CSS. The increased efficiencies in the MSS are due to its improved evaporation and condensation rates, which enhance the energy utilization in the process of converting saline water to freshwater. Full article

Virus-like particles (VLPs) based on the capsid protein (CP) of the ssRNA bacteriophage Beihai32 represent a promising nanoscale platform for the presentation of heterologous peptides. Previous studies have shown that the C-terminus of the CP tolerates long insertions without compromising VLP assembly. Here, we demonstrate that the N-terminus is similarly permissive to extended insertions. Hybrid CPs with one to four copies of the influenza A virus M2e peptide fused to the N-terminus were expressed in Escherichia coli. Fusion proteins containing four copies of M2e self-assembled into spherical VLPs, displaying the inserted peptides on the surface. Subcutaneous immunization of mice with chimeric VLPs induced high titers of M2e-specific antibodies. Unlike C-terminal fusions, the N-terminal insertion prevented the induction of anti-carrier antibody response indicting masking of the carrier protein in the chimeric VLP. To evaluate the capacity of the N-terminus for larger inserts, green fluorescent protein (GFP, 238 a.a.) was attached to the N-terminus of CP. The hybrid protein was expressed in Escherichia coli and formed VLPs. GFP was displayed on the particle surface and retained fluorescent activity. Overall, the phage Beihai32 CP is a versatile platform for the presentation of peptide antigens, supporting its potential application in VLP-based vaccine design. Full article

Soft piezoelectric electronic skins are expected to work reliably under repeated joint bending, where both stretchability and stress transfer efficiency are important. In this work, a BaTiO₃/PDMS piezoelectric electronic skin, denoted as BPPE-skin, was prepared by a blade-coating method. Rather than only increasing the amount of piezoelectric filler, this study focuses on how the PDMS matrix composition affects the mechanical deformation and electrical response of the composite. The PDMS base-to-curing-agent ratio was adjusted from 5:1 to 30:1, and the BaTiO₃ loading was varied from 10 to 90 wt%. Tensile tests show that increasing the base-to-curing-agent ratio reduces the elastic modulus and improves stretchability, while excessive softening weakens effective stress transfer. As a result, the voltage output reaches its highest value at a 10:1 ratio. Increasing the BaTiO₃ content further enhances the output, mainly because more active piezoelectric particles participate in electromechanical conversion. The optimized film, containing 90 wt% BaTiO₃ with a 10:1 PDMS ratio, maintains good flexibility and can be attached conformally to different body joints. Tests on the knee, elbow, wrist, and fingers produce distinct voltage patterns during bending motions, indicating the potential of BPPE-skin for wearable, self-powered human motion monitoring. Full article

End-of-life photovoltaic modules represent a complex waste stream in which polyolefin elastomer (POE) encapsulants are increasingly important but insufficiently characterized after recovery. This study evaluates the structural, morphological and thermal state of POE-rich encapsulant residues obtained from laser-treated fragments of a crystalline-silicon photovoltaic module after approximately five years of field operation, focusing on material quality rather than process optimization. Reference POE and representative polymer-rich residues were examined by FTIR-ATR, TGA/DTG under nitrogen and SEM/EDS. FTIR-ATR showed characteristic polyolefin bands at approximately 2915–2847, 1463 and 718–719 cm⁻¹ in both reference POE and treated residues, indicating retention of the hydrocarbon backbone. Treated residues exhibited additional features in the 1800–1500 and 1100–1000 cm⁻¹ regions, attributed to oxygen-containing surface species and interfacial glass/silicon contributions. TGA/DTG revealed a similar main decomposition range for the POE-rich residues, with DTG peaks mainly between 471.5 and 474.3 °C, while residual mass varied from 1.94 to 23.03%, compared with 0.04% for reference POE. SEM/EDS confirmed heterogeneous surfaces and local silicon/oxygen-rich particles attached to or embedded in the polymer-rich residues. The results show that POE-rich waste fractions can preserve the main polyolefin structure, but their valorization requires control of inorganic contamination, especially for cut, cracked or mechanically damaged modules. Full article

The charged-lepton masses are free Yukawa-sector parameters in the Standard Model, whereas their measured pole-mass ratios display a highly structured hierarchy and satisfy the Koide relation to notable accuracy. This paper develops a conditional mathematical-physics proposal in which these dimensionless regularities arise from a charge-neutral parent carrier-defect architecture before effective Higgs–Yukawa read-out. The assumptions of the construction are stated explicitly as structural postulates and are separated from their derived consequences. The central rule assigns equal primitive weight to admissible internal sectors that are indistinguishable at the level where they first become exposed; protected sectors are removed before counting, and later refinements are conditional on previously selected sectors. Under this rule, the Koide relation follows as an equal-power theorem between the democratic parent component and the orthogonal branch-splitting component of the charged-lepton root-amplitude state. A minimal endpoint construction then yields a rapidly stabilizing charged tower for the electron–muon ratio. Because deeper charged terms are too small to remove the remaining residual, the framework assigns that residual to the continuation-dual neutral branch. The resulting neutral overlap gives a leading solar-angle target of 33.21 degrees and closes the electron–muon ratio at the present experimental precision; the Koide relation then fixes the corresponding tau ratios. The construction does not replace the Standard Model but is proposed as a selection rule for the boundary values of effective charged-lepton Yukawa parameters, with pole masses used because the claimed invariant is attached to completed asymptotic particle read-out. Running parameters, the absolute mass scale, and the full Pontecorvo–Maki–Nakagawa–Sakata (PMNS) matrix remain outside the present derivation. The proposal has explicit failure conditions: improved measurements can exclude the predicted tau ratios or solar-angle target, and the claimed conditional uniqueness fails if a different counting scheme satisfies the same postulates while producing different endpoint weights. Full article

Construction and demolition waste valorization as recycled aggregates remains largely underdeveloped in North African urban contexts. This study presents the first normatively referenced characterization of recycled aggregates from ten sites in Fez, Morocco, combined with experimental C25/30 concrete formulation using the Dreux-Gorisse method. Physical, mechanical, and chemical analyses reveal high water absorption (9.98 ± 0.94%), low particle density (2197 kg/m³), sub-standard sand equivalent (39.4%), and elevated methylene blue (3.06 g/kg), all governed by attached cementitious mortar content. Principal component analysis identifies three groups: Cluster A (E2, E6, E8), directly valorizable for structural use; Cluster B (E3, E4, E7, E10), requiring fine-fraction removal (<80 µm) prior to concrete incorporation; and an intermediate group (E1, E5, E9), suitable for non-structural applications. Concrete mixes from a composite blend of all ten samples were experimentally validated on cylindrical specimens. At 25% substitution, the 28-day compressive strength reaches 22–28 MPa, achieving marginal C25/30 compliance when superplasticizer and pre-wetting correction (9.98 L/100 kg recycled aggregate) are applied; substitution at 50% and above does not meet structural requirements (18–24 MPa). Durability assessments confirm increasing carbonation depth (7–11 mm at 25%) and moderate-to-high chloride permeability, underscoring the need for source-selective sampling and pre-treatment in urban construction and demolition waste valorization programs, particularly in North African and Maghreb contexts where construction materials and building practices are broadly similar and demolition waste is typically processed without prior sorting. Full article

The selective separation of sphalerite from Fe-bearing sulphides remains a persistent challenge in the flotation of complex sulphide ores and can lead to Zn misreporting to Fe-bearing concentrates. This study aimed to identify the origins of Zn misreporting to a pyrite concentrate and to evaluate whether regrinding-assisted flotation could mitigate Zn misreporting. XRF, XRD, zinc phase analysis, flotation experiments, and process mineralogical characterisation were used to determine Zn deportment and evaluate the effect of regrinding on mitigating Zn misreporting to the pyrite concentrate. The results showed that the Zn was mainly associated with sphalerite rather than water-soluble Zn species. Reagent adjustment and additional cleaning stages reduced Zn misreporting moderately, but were insufficient to fully separate Zn-bearing phases from the pyrite concentrate. Process mineralogical characterisation further revealed that Zn was predominantly hosted in sphalerite, which commonly occurred as attached, locked, or disseminated particles associated with pyrite. Under the same Na₂SiO₃ dosage, regrinding-assisted flotation reduced the Zn grade in the final pyrite concentrate from 0.29% to 0.14%, indicating reduced Zn misreporting. These findings indicate that close sphalerite–pyrite association and incomplete sphalerite liberation were the principal mineralogical factors governing Zn misreporting, while regrinding-assisted flotation provides a practical approach for reducing Zn misreporting to pyrite concentrates. This study provides a process mineralogy-guided approach for diagnosing Zn misreporting and improving impurity control in pyrite-rich concentrate production. Full article