Search Results (3,585)

Background: Dental caries remains one of the most prevalent oral diseases worldwide, largely driven by the virulence of Streptococcus mutans. Although plant phenolics from green tea and pomegranate are known for their antimicrobial properties, their molecular mechanisms of action against key S. mutans virulence targets remain insufficiently characterized. Aim: This study investigated the antibacterial and anti-virulence properties of Viroelixir, a phenolic-rich formulation derived from green tea (Camellia sinensis) and pomegranate (Punica granatum), against S. mutans, with particular emphasis on predictive molecular docking interactions with critical virulence-associated proteins. Methods: Viroelixir phytochemical composition was characterized by LC–MS using a C18 reverse-phase column and negative electrospray ionization mode. Antibacterial activity was evaluated using growth kinetics, agar plating, and crystal violet assays. Acidogenicity, hemolytic activity, and biofilm formation were assessed using pH modulation, hemolysis assays, SEM, and biofilm biomass quantification. Virulence gene expression was analyzed by RT-qPCR. In silico molecular docking was performed to explore potential interactions between major LC–MS-supported phenolic constituents and S. mutans virulence proteins, including glucosyltransferase B (GtfB), LuxS, and SpaP. Biocompatibility was evaluated in human gingival epithelial cells. Results: The LC-MS analysis revealed a complex mixture of phenolic compounds consistent with catechins and ellagitannins. Compound identification was considered tentative and based on mass spectral range and chromatographic behavior. Viroelixir significantly inhibited S. mutans growth, acid production, hemolytic activity, and biofilm formation in a concentration-dependent manner. Key virulence genes were markedly downregulated. Docking analyses suggested stable binding of selected phenolics—particularly punicalagin, catechin, and epigallocatechin—within the active sites of GtfB, LuxS, and SpaP. Importantly, Viroelixir showed no cytotoxic effects on gingival epithelial cells. Conclusions: Viroelixir exerts potent antibacterial and anti-virulence effects against S. mutans through a multi-target mechanism combining transcriptional suppression and predictive molecular inhibition of virulence proteins, supporting its potential as a safe, natural therapeutic for caries prevention. Full article

The precipitation of nanoscale HfO₂ plays a critical role in the high-temperature creep properties of Fe-Cr-Al electrical heating alloys. However, the atomic-scale initial nucleation and growth mechanisms remain unclear, hindering the precise design of precipitates based on Hf microalloying. In this study, classical molecular dynamics simulations implemented in LAMMPS were employed to investigate the formation and evolution of Hf-O clusters at 1773 K, 1873 K, and 2000 K. The Fe-Cr-Al-Hf-O system was described by hybrid potential functions, whose reliability was verified by lattice-parameter calculations in good agreement with literature values. The simulation results demonstrate that Hf atoms and O atoms attract each other, forming stable Hf-O clusters. At higher temperatures, the diffusion capabilities of Hf and O atoms are enhanced, the number of Hf-O bonds grows, and the size of the largest cluster expands, indicating that elevated temperatures promote cluster growth. The calculated diffusion activation energy of Hf and O atoms indicates that increasing temperature promotes O atom diffusion more significantly. Analysis of the cluster radius of pair gyration and average atomic energy reveals that Hf-O clusters formed at 1873 K exhibit more compact and stable structural characteristics. Radial distribution function analysis further revealed that the atomic arrangement of neighboring atoms in Hf-O clusters closely resembles the relaxed HfO₂ crystal structure at the same temperature, indicating that Hf-O clusters serve as critical nucleation cores promoting the precipitation of HfO₂ crystals. This study elucidates the dynamic formation mechanism and structural evolution of Hf-O clusters in Fe-Cr-Al alloys at the atomic scale, providing valuable guidance for the optimized design of precise control over HfO₂ nanoprecipitates. Full article

To address the issues of high cutting temperatures and severe tool wear during titanium alloy machining, this study proposes a hybrid surface modification strategy combining micro-textures and multicomponent titanium nitride (TiN)-based coatings on cemented carbide tools. Using YG8 cemented carbide as the substrate, micro-dimple textures were fabricated by fiber laser, and three coatings with different architectures (TiAlSiN, TiSiN/TiAlN, and TiSiN/TiAlSiN/TiAlN) were deposited via multi-arc ion plating technology. Based on a two-factor (texture diameter and texture spacing) and three-level orthogonal experiment, the evolution behaviors of surface morphology, phase composition, and mechanical properties of the textured multicomponent TiN-based coatings were systematically characterized and comparatively analyzed. The results reveal that: compared to the monolithic-structured TiAlSiN coating, the TiSiN/TiAlSiN/TiAlN and TiSiN/TiAlN composite coatings with multilayered composite structures can effectively relieve the residual stress inside the film–substrate system, and significantly suppress the phenomena of coating cracking and localized spallation caused by irregular protrusions of the recast layer at the micro-texture edges. X-ray diffraction (XRD) and crystallite size analyses indicate that the amorphous Si₃N₄ phase promoted by the Si element in the composite coatings effectively impedes the growth of TiN columnar crystals, achieving significant grain refinement. Mechanical property tests confirm that the existence of multicomponent composite interfaces effectively hinders dislocation movement. Among them, the textured TiSiN/TiAlSiN/TiAlN composite coating exhibits the optimal comprehensive performance; its microhardness, nanohardness, and H/E ratio (characterizing the resistance to plastic deformation) are increased by 17.94%, 8%, and approximately 45%, respectively, compared to those of the textured TiAlSiN coating. This study deeply elucidates the synergistic strengthening and toughening mechanisms between micro-texture parameters and the internal structures of the coatings, providing important theoretical guidance and experimental data support for the surface design of long-lifespan tools oriented towards the high-efficiency machining of titanium alloys. Full article

Bi-doped rare-earth iron garnet (Bi:RIG) single crystals are the core of optical isolators, and demand for them is surging due to the development of artificial intelligence (AI) technology. In this work, bismuth-doped terbium iron garnet (Bi:TbIG) single crystals with a composition of Bi_0.86Tb_2.14Fe₅O₁₂ and a size of 37 mm were successfully grown by the top-seeded solution growth (TSSG) method using a lead-containing flux system. These crystals exhibited a regular rhombic dodecahedron morphology enclosed by the {110} plane, and a growth rate of 0.018 mm/h perpendicular to the {110} planes. Systematic characterizations revealed that the crystals exhibited good compositional homogeneity, with no obvious Fe, Tb and Bi segregation from center to edge. Rocking curve tests presented a full width at half maximum of 172 arcsec. X-ray photoelectron spectroscopy (XPS) results demonstrated that Fe exists exclusively in the +3 valence state without detectable Fe²⁺, whereas Tb is present in the +4 valence state. In addition, O was lattice O²⁻, without obvious defects. Magneto-optical tests indicated that the uncoated TSSG-grown Bi:TbIG crystals had 71% transmittance in the 1200~1600 nm waveband, and a Faraday rotation coefficient of 0.132°/μm at 1310 nm. The 11 × 11 mm samples exhibited an extinction ratio stably above 40 dB. The 349 μm thick samples meet the application requirements of miniaturized optical isolators. This study verifies the feasibility of TSSG for growing Bi:TbIG single crystals, offering a new technical route for Bi:TbIG growth with potential value for practical application. Full article

ALD is a precise thin-film deposition technique based on self-limiting surface reactions. A crucial stage in each ALD cycle is the purge step, which removes excess precursor molecules and reaction by-products from the reactor chamber, preventing uncontrolled gas-phase reactions that could degrade film quality. Despite its fundamental importance, the impact of purge dynamics on film growth and structure remains insufficiently explored. ZnO and ZrO₂ films were deposited in reactors with different effective chamber volumes (47 and 470 cm³), enabling a systematic study of gas residence time effects. Our results demonstrate that the purge mode—dynamic versus static vacuum—strongly affects the growth behavior, crystallinity, and surface morphology of ALD oxides. Dynamic purging leads to smoother, more uniform, and better-crystallized films, whereas static exposure results in lower structural and morphological quality, particularly for ZrO₂. Importantly, these results demonstrate that purge-mode engineering provides a powerful and cost-effective route for tailoring oxide film structure without altering the precursor chemistry or deposition temperature. To validate the practical integration of these optimized films, functional phosphor and LED structures were fabricated, confirming that the controlled microstructure is well-suited for optoelectronic applications. This approach also offers new possibilities for controlling film properties in sensors and catalysts. Full article

Heavy precipitation in Northeast China is frequently modulated by the Northeast China Cold Vortex (NCCV), although the microphysical processes within squall lines under such conditions remain insufficiently understood. This study presents a comprehensive analysis of an NCCV-influenced squall line in Liaoning Province, utilizing coordinated S-band polarimetric radar and surface disdrometer observations. The raindrop size distribution (DSD) characteristics and three-dimensional microphysical structure are systematically examined for both convective and stratiform regimes. A comparative analysis of DSD and warm-rain microphysical mechanisms is also conducted with a Mei-yu event. Results show that convective rain in the NCCV squall line exhibits a continental-type DSD, characterized by fewer but larger raindrops compared to other heavy rainfalls in China. In contrast, the Mei-yu frontal convection under NCCV influence exhibits a transitional DSD pattern between the maritime and continental types, with raindrops smaller and denser than those in the NCCV squall line. Vertical structure of the mature squall line shows prominent differential reflectivity (Z_DR) and specific differential phase (K_DP) columns above the melting level within the convective region, indicating vigorous riming growth of graupel and hail driven by strong updrafts. Meanwhile, the stratiform region is characterized by ice crystals and aggregates, formed primarily through deposition and aggregation processes. The subsequent melting of ice-phase particles followed by collision–coalescence and evaporation-driven size sorting shapes the large but sparse raindrops in the NCCV squall line. Comparison with Mei-yu convection demonstrates that surface DSD is shaped by environmental conditions and vertical microphysics. The drier, more unstable environment in the NCCV squall line favors deep convection with active ice-phase processes, while the relatively moist and stable environment of the Mei-yu convection supports shallower convection dominated by warm-rain processes. Future multi-case studies with integrated observations are needed to quantify how environmental and aerosol conditions modulate these heavy precipitation processes. Full article

Soil salinization is a significant global challenge that severely impacts agricultural productivity, particularly through its negative effects on crop growth and yield. Peanuts (Arachis hypogaea L.) are an important oil crop. One of the major goals in peanut breeding programs is to develop varieties with both high oil content and salt tolerance. Previously, we obtained a peanut line (HO) with high oil content through mutagenesis, which showed higher salt tolerance than its parental line (HY20). In this study, we employed multiple approaches including anatomical, physiological, and transcriptomic analyses to elucidate salt tolerance mechanisms of the HO peanut line. Under salt stress, the HO line exhibited better-developed vascular structures, with increased root vessel diameter and higher crystal idioblast density in leaves compared to HY20. HO also showed enhanced antioxidant enzyme activities, with POD and SOD activities higher than HY20. Photosynthetic efficiency was substantially improved in HO, with Fv/Fm decreasing under severe salt stress. Additionally, HO maintained a lower Na⁺/K⁺ ratio and higher linolenic acid content under salt stress. Transcriptomic analysis revealed up-regulated lignin biosynthesis genes in HO. This study established potential connections between salt stress tolerance and oil biosynthesis in peanuts, providing insights that could be leveraged for the development of high-yield and salt-resistant varieties. Full article

Membrane distillation (MD) is an attractive technology for desalination driven by renewable energy and low-grade heat sources. However, specific practical guidelines for intermittent operations, typical of such alternative energy sources, are still limited—particularly with respect to established shutdown measures to mitigate adverse effects on the overall system performance. The present study compares continuous and intermittent air-gap MD desalination at a lab-scale by evaluating performance parameters and scaling development. Apart from a slightly lower distillate productivity and a similar distillate quality under intermittent conditions, no direct difference in MD performance between continuous and intermittent experiments was detected. Nevertheless, online monitoring by image analysis with optical coherence tomography revealed more advanced scaling development during intermittent operation, with larger scaling volumes and cover ratios, particularly after implementing a membrane rinsing and preservation protocol with demineralized water. Membrane autopsies revealed that intermittency led to alterations in the development of the crystal morphology of predominantly CaCO₃ scaling. These changes were attributed to enhanced nucleation and modified growth kinetics triggered by recurring shutdown and start-up phases. Overall, the findings showed that intermittency had an adverse effect in terms of scaling behavior, highlighting the need for operating protocols tailored to each specific MD application. Full article

Large-sized, room-temperature ultrafast scintillator single crystals are highly demanded for fast timing applications such as time of flight–positron emission tomography, high-speed medical imaging, and pulse heavy-ray detection. Sub-nanosecond scintillation was discovered in 16 mm sized CsPbCl₃Br_x single crystals in our previous research. In this work, the crystal size of CsPbCl₃Br_0.03 was enlarged to 2 inches (50.8 mm). Meanwhile, by precisely optimizing the vertical Bridgman growth process, we further increased the concentration of Br dopant to realize even faster scintillation decay. In this study, we conducted a series of tests on the grown crystals, including temperature-dependent photoluminescence tests, alpha particle excitation tests, X-ray imaging tests, etc. Via the strategy of the incorporation of Br₂, Br dopant introduces highly efficient fast recombination centers in perovskite CsPbCl₃Br_0.03 crystals, resulting in an unprecedently fast scintillation decay time of 303 ps under ²⁴¹Am α-particle excitation, which is significantly shorter than that of the pure CsPbCl₃ and all other perovskites by at least two orders of magnitude. Benefiting from the excellent optical transparency and high crystalline quality of the CsPbCl₃Br_0.03 crystal, an X-ray spatial resolution of up to 20 lp/mm is achieved. These results further demonstrate the great potential of large-sized CsPbCl₃Br_x single crystals for fast timing applications. Full article

A new series of eight novel etodolac-based 1,3,4-oxadiazoles was synthesized, characterized, and tested in silico in multidimensional routes, starting with etodolac, a well-known nonsteroidal anti-inflammatory medication (NSAID). In silico studies were performed prior to synthesis using the molecular docking technique in CCDC GOLD suite software (2025.3) to assess the interactions with two key targets involved in cancer pathogenesis: the crystal structure of the epidermal growth factor receptor EGFR tyrosine kinase domain (PDB ID: 4HJO) and the matrix metalloproteinase (MMP-9) complex (PDB ID: 5CUH). ADME studies were performed to assess the physicochemical properties of the synthesized molecules. Importantly, biotransformation prediction also indicated that the derivatives possess high metabolic stability, with hydroxylation of the thio-ether group as the primary predicted biotransformation route. All compounds were characterized using melting point, FT-IR, ¹H-NMR, and ¹³C-NMR spectroscopy. In vitro and/or in vivo experiments are needed to confirm this preliminary anticancer study. Full article

CoFe₂O₄ nanoparticles were prepared using a hydrothermal method. All the studied samples were single-phase and were crystallized in a cubic Fd-3m structure. XRD and TEM analyses revealed that the particles had average sizes between 5 and 22 nm. It has been shown that, by using the PVP of different molecular masses, trends of growth and crystallization can be established, obtaining elongated 40 k, cubical 58 k, and rhomboidal 360 kg/mol nanoparticles. While using Ethylene glycol as solvent, the formation of separated “raspberry”-like nanostructures was revealed. The saturation magnetizations are somewhat smaller compared with crystalline CoFe₂O₄ saturation magnetization, but are high enough to have possible biomedical applications. FC and ZFC measurements show that the blocking temperature was around 100 K for the CF5 sample and around 20 K for the FC6 sample. The calculated anisotropy constants were between 7 and 10 kJ/m³, being close to previously reported values. The calculated blocking temperatures are in good agreement with experimental ones. The M_r/Ms ratio at room temperature was lower than 0.5, confirming the predominance of magnetostatic interactions. This paper serves as a good starting point for researchers seeking to synthesize a CoFe₂O₄ system with a desired size and growth tendency at the nanometer scale. Full article

This study proposes a data-driven framework with post hoc interpretability analysis for one-step-ahead crystal diameter prediction in the Czochralski (CZ) silicon single-crystal growth process. To address the strong multivariable coupling, nonlinear dynamics, variable-specific delays, and difficulty of online measurement in CZ growth, the maximal information coefficient (MIC) was first used to screen key auxiliary variables from industrial process data. The Grey Wolf Optimizer (GWO) was then employed for multi-variable delay estimation and feature alignment, and a hybrid temporal convolutional network (TCN)–long short-term memory (LSTM) model was constructed to combine local temporal feature extraction with long-term dependency learning. Four input configurations were designed according to whether lag alignment and diameter history were included, and the proposed TCN-LSTM was systematically compared with standalone TCN and LSTM models. The results show that both diameter history and delay alignment improve prediction performance. Under the current single-run evaluation protocol, the TCN-LSTM configurations yielded lower prediction errors than the corresponding TCN and LSTM models under the same input settings. Under the withlag-withY configuration, the TCN-LSTM model achieved MSE = 0.00259, RMSE = 0.05087, MAE = 0.03949, and R² = 0.96982. After GWO-based hyperparameter optimization, the best TCN-LSTM configuration further improved to MSE = 0.00239, RMSE = 0.04894, MAE = 0.03651, and R² = 0.97207. SHAP-based analysis was further used to provide a post hoc interpretation of the relative contributions of key process variables to diameter variation. Overall, the proposed framework provides a data-driven prediction approach and may support subsequent process analysis and optimization in industrial CZ growth. Full article

Gypsum (CaSO₄·2H₂O) crystallization is highly sensitive to the supersaturation pathway, which governs the balance between nucleation and crystal growth and ultimately controls growth morphology. In this study, gypsum was synthesized via two contrasting routes—diffusion-controlled crystallization and rapid precipitation—using identical reactant systems to enable a direct comparison of distinct kinetic regimes. A polycarboxylate-based superplasticizer was incorporated to investigate pathway-dependent additive effects. Time-resolved observations reveal that rapid precipitation is characterized by high nucleation density under steep supersaturation, whereas diffusion-controlled crystallization proceeds under gradually increasing supersaturation with restricted nucleation and sustained anisotropic growth. Powder X-ray diffraction confirms the formation of phase-pure gypsum under all conditions. Scanning electron microscopy shows that the presence of the superplasticizer reduces crystal number density and modifies crystal habit in both pathways, although the extent and manifestation of these effects depend strongly on the governing kinetic regime. Under diffusion-controlled conditions, the increasing superplasticizer dosage promotes the transition from elongated to more tabular morphologies, while rapid precipitation results in dense, intergrown aggregates under high supersaturation. Overall, the results demonstrate that the effectiveness of the superplasticizer is not intrinsic but depends on the crystallization pathway. These findings provide new insight into how supersaturation profiles mediate the interplay between additive interactions and growth processes, enabling improved control over gypsum crystal morphology. Full article

Improving the interfacial compatibility between cellulose and poly(butylene adipate-co-terephthalate) (PBAT) is critical for enhancing the performance of PBAT-based composites. Here, microcrystalline cellulose (MCC) was homogeneously silanized at the molecular chain level using t-hexyldimethylchlorosilane (TDMS-Cl) as the modifier, yielding t-hexyldimethylsilylated cellulose (TDMS-Cell). TDMS-Cell/PBAT composite films were then prepared by solution blending and casting in tetrahydrofuran (THF). Structural characterizations confirmed the successful grafting of TDMS-Cl onto cellulose chains, resulting in TDMS-Cell with a degree of substitution of approximately 2. Microstructural observations combined with thermal analysis revealed that TDMS-Cell exerted a dual effect on the crystallization behavior of PBAT: it acted as a heterogeneous nucleating agent that increased the crystallization temperature, while the pronounced steric hindrance simultaneously suppressed crystal growth. Mechanical testing showed that simultaneous strengthening and toughening were achieved at an optimal TDMS-Cell loading of 3–5 wt%. Specifically, the tensile strength increased from ~16 MPa for neat PBAT to 21 MPa (31.25% improvement), and the elongation at break increased from ~700% to 964% (37.7% improvement). In addition, the incorporation of an appropriate amount of TDMS-Cell effectively enhanced the surface hydrophobicity of the composite films. At higher filler loading, however, solvent evaporation-induced phase separation led to self-aggregation of TDMS-Cell, which in turn deteriorated both the mechanical properties and surface hydrophobicity of the composites. Overall, this work systematically elucidates the structure–property relationships of silanized cellulose/PBAT composites in a homogeneous solution system, providing a rational basis for interfacial design and property optimization of PBAT/biomass-based composite materials. The prepared TDMS-Cell/PBAT composite films with balanced mechanical strength, tunable crystallization behavior, and improved surface hydrophobicity exhibit great potential for practical applications in high-performance flexible packaging materials, functional film substrates, lightweight composite structural components, and tunable hydrophobicity coating substrates. Full article

Metal-chalcogenide compounds with perovskite-type compositions have drawn increasing attention for their optical properties for solar energy conversion. Herein, a new α-type polymorph of the ternary sulfide SrHfS₃ is described, crystallizing in the NH₄CdCl₃ structure type. The yellow-colored plate-shaped crystals were synthesized at 1173 K using an elemental tin flux in an evacuated sealed tube. Its crystal structure was characterized at room temperature using single crystal X-ray diffraction to form in the orthorhombic Pnma space group, with the refined cell parameters of a = 8.5041(4) Å, b = 3.8004(2) Å, c = 13.8935(6) Å, and V = 449.02(4) ų. The structure comprises five independent crystallographic sites, having one Sr, one Hf, and three S sites. The structure can be described as containing one-dimensional chains of distorted HfS₆ octahedra extending down the b-axis to form ${\displaystyle \genfrac{}{}{0pt}{}{1}{\infty }}[$HfS₃]²⁻ strips of edge-sharing octahedra. The Sr atoms act as charge-balancing space fillers in the structure. High-purity bulk samples of α-SrHfS₃ could be prepared for measurement of its bandgap by optical diffuse-reflectance spectroscopy, showing a direct bandgap of 2.1(1) eV. Results of electronic structure calculations are consistent with this bandgap and type. The conduction and valence band edges stem from the respective empty Hf d-orbitals and the filled S p-orbital states. In summary, crystal growth of the α-type polymorph of SrHfS₃ has been demonstrated using a Sn flux approach, which can facilitate future broader synthetic explorations at lower temperatures. Full article