Search Results (740)

Epoxy resins are valuable in aerospace, electronics, and high-performance industries; however, their inherently low thermal conductivity (TC) limits applications requiring effective heat dissipation. Recent reports suggest that certain liquid crystalline or partially crystalline epoxy formulations can achieve higher TC, even exceeding 1 W/(m·K). To investigate this, 17 epoxy formulations were prepared, including the commonly used diglycidyl ether of bisphenol A (DGEBA) and two custom-synthesized diepoxides: TME4, which contains rigid aromatic ester linkages with a C4 aliphatic spacer, and LCE-DP, featuring rigid imine bonds. Thermal conductivity was measured using four techniques: laser flash analysis (LFA), modified transient plane source (MTPS), time-domain thermoreflectance (TDTR), and displacement thermo-optic phase spectroscopy (D-TOPS). Additionally, small-angle and wide-angle X-ray scattering (SAXS/WAXS) were performed to detect crystalline or liquid crystalline domains. All formulations exhibited TC values ranging from 0.13 to 0.32 W/(m·K). The TME4–DDS systems, previously reported to be near 1 W/(m·K), consistently measured between 0.26 and 0.30 W/(m·K). Thus, under our synthesis and curing conditions, the elevated TC reported in prior studies was not reproduced, and no strong evidence of crystallinity was observed; indications of local ordering did not translate into higher conductivity. Variations in TC among methods often matched or exceeded the gains attributed to mesophase formation. More broadly, evidence for crystallinity in epoxy thermosets appears weak, consistent with the notion that crosslinking suppresses long-range ordering. Full article

Melt-spun PA6/TiO₂ fibers with TiO₂ modified by silane coupling agents KH550 and KH570 at 0, 1.6, and 4 wt% provide a practical testbed to address three fiber-centric gaps: transferable interphase quantification, interphase-resolved indications of compatibility, and a reproducible kinetics–structure–property link. This work proposes, for the first time at fiber scale, a four-phase partition into crystal (c), crystal-adjacent rigid amorphous fraction (RAF-c), interfacial rigid amorphous fraction (RAF-i), and mobile amorphous fraction (MAF), and extracts an interfacial triad consisting of the specific interfacial area (S_v), polymer-only RAF-i fraction expressed per composite volume (Γ_i), and interphase thickness (t_i) from SAXS invariants to establish a quantitative interphase-structure–property framework. A documented SAXS/DSC/WAXS workflow partitions the polymer into the above four components on a polymer-only basis. Upon filling, Γ_i increases while RAF-c decreases, leaving the total RAF approximately conserved. Under identical cooling, DSC shows the crystallization peak temperature is higher by 1.6–4.3 °C and has longer half-times, indicating enhanced heterogeneous nucleation together with growth are increasingly limited by interphase confinement. At 4 wt% loading, KH570-modified fibers versus KH550-modified fibers exhibit higher α-phase orientation (Hermans factor f(α): 0.697 vs. 0.414) but an ~89.4% lower α/γ ratio. At the macroscale, compared to pure (neat) PA6, 4 wt% KH550- and KH570-modified fibers show tenacity enhancements of ~9.5% and ~33.3%, with elongation decreased by ~31–68%. These trends reflect orientation-driven stiffening accompanied by a reduction in the mobile amorphous fraction and stronger interphase constraints on chain mobility. Knitted fabrics achieve a UV protection factor (UPF) of at least 50, whereas pure PA6 fabrics show only ~5.0, corresponding to ≥16-fold improvement. Taken together, the SAXS-derived descriptors (S_v, Γ_i, t_i) provide transferable interphase quantification and, together with WAXS and DSC, yield a reproducible link from interfacial geometry to kinetics, structure, and properties, revealing two limiting regimes—orientation-dominated and phase-fraction-dominated. Full article

In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized via a green chemistry approach using aqueous extract of Camellia sinensis var. assamica (Assam green tea) as a bioreductant and stabilizing agent. Phytochemical analysis of the extract revealed high levels of phenolics (338.57 ± 3.90 mg GAE/mL) and flavonoids (123.92 ± 1.34 µg QE/mL), along with strong antioxidant and reducing activity, supporting its efficacy in nanoparticle formation. ZnO NPs were synthesized at various extract concentrations, with 25% yielding optimal characteristics based on UV–Vis spectrophotometry (λ_Max ≈ 390–410 nm). Structural characterization using XRD confirmed the hexagonal wurtzite phase, and SAXS indicated particle sizes of 58–60 nm. FE-SEM analysis showed semi-spherical agglomerated particles ranging from 74 to 76 nm, while EDX verified the elemental purity of Zn and O. FT-IR spectroscopy confirmed the presence of Zn–O stretching and phytochemical residues on the nanoparticle surface. Stability studies over four weeks revealed red shifts in absorbance and reduced peak intensity at ambient and elevated temperatures, suggesting nanoparticle agglomeration. Antimicrobial assays demonstrated strong antifungal activity of the ZnO NP solution against Candida albicans and, upon concentration, significant antibacterial activity against Streptococcus mutans. The synthesized ZnO NPs exhibit promising potential as eco-friendly antimicrobial agents, particularly for applications in oral healthcare. Full article

Background: Two-stage septic hip revision arthroplasty has higher mortality rates than aseptic hip revision arthroplasty, and patients over 75 years have higher fracture rates than younger patients after cementless total hip arthroplasty. Therefore, the aim of this study was to examine whether two-stage septic hip revision arthroplasty in older patients leads to higher complication and mortality rates, as well as whether changing to cementless hip prostheses in older patients could lead to higher fracture and subsidence rates of the stem prosthesis than in younger patients. Material and Methods: In total, 286 two-stage-revision procedures for periprosthetic infections of the hip in 186 patients younger and 118 patients older than 75 years were followed for a minimum of 24 (50.24 ± 20.77) months. A total of 71.3% of procedures were performed via a transfemoral approach using cementless cups and revision stems (93.7%). Complications and mortality were analyzed retrospectively. Results: There was a one-year mortality rate of 1.0% with no difference in the groups, and a general mortality rate of 2.8% with a significantly higher rate in older adults than in the younger group (5.9% vs. 0.6%; p = 0.01). The rate of fractures of the bony flap in transfemoral approaches (9.1%), fissure rate of the isthmus (2.8%), rate of subsidence of cementless stems (1.0%), and rate of reinfections (4.89%) did not differ between the two groups. The general complication rate (not associated with cementless two-stage septic revision) (22.0%) was significantly higher in the older patient group (33.9% vs. 13.7%; p < 0.001). Conclusions: Septic two-stage revision hip arthroplasty, mostly using a transfemoral approach and cementless reimplantation, does not result in a higher one-year mortality rate, reinfection rate, and rate of fissures and fractures of the bony flap, but demonstrates a generally higher mortality and complication rate in older adults. This should be taken into consideration when determining the indication and when offering advice to older adults. Full article

Recent studies on semi-dilute Calf-Thymus DNA (CT-DNA) solutions have revealed the presence of birefringence and small-scale textures influenced by shear and ionic strength. In this study, we investigate these phenomena on the same solutions to elucidate the underlying shear-induced supramolecular organization and relaxation dynamics using rheo-birefringence, rheology, and rheo-SAXS (small-angle X-ray scattering). Static SAXS confirmed concentration-dependent inter-chain correlations in the 15–25 nm range, while rheology revealed a slipping yield-stress behavior. Oscillatory strain sweep and steady state rheo-birefringence experiments correlated the appearance of textures with the onset of flow and a stress plateau observed over a shear rate range from approximately 1 to 1000 s⁻¹. Transient rheo-birefringence and rheo-SAXS revealed two distinct relaxation mechanisms on well-separated time scales: a fast process lasting a few seconds, inversely proportional to the shear rate, consistent with the orientational relaxation of DNA segments on a ~20 nm scale; and a slower relaxation over tens of seconds, independent of the shear rate, associated with the disappearance of textures, and attributed to a diffusive process. These findings provide significant insights into the mechanisms governing DNA organization and dynamics in semi-dilute solutions under flow and highlight the need for temporally resolved start-up rheo-SAXS and rheo-birefringence measurements, as well as theoretical models describing these processes across various spatial and temporal scales. Full article

The membranes of halophilic archaea are a source of novel biomaterials, mainly of isoprenoid nature, with therapeutic properties practically unraveled. Here, we explored the antitumoral activity of neutral archaeolipids (NAs, such as bacterioruberin, astaxanthin, and dihydrosqualene) present in the total archaeolipids (TAs) (a fraction from the first step of lipid extraction by the modified Blight and Dyer technique) extracted from halophilic archaea Halorubrum tebenquichense, and formulated as TA-nanoarchaeosomes (TA: polar archaeolipids (PAs): Tween 80, 5:5:4 w:w:w, TA-nanoARC). The structure of 300.3 ± 84.2 nm TA-nanoARC of 0.59 ± 0.12 polydispersity index and −20 ± 3.7 mV ζ potential as determined by SAXS modelling, revealed that NA reduced the hydrophobic core and enlarged its hydrophilic section in comparison to TA-lacking bilayers (nanoARC), while preserving the width (~50 Å) and unilamellarity. Stable to storage and nebulization, TA-nanoARC was cytotoxic on A549 cells after 48 h, with an IC50 expressed as [bacterioruberin] of 0.15 μg/mL (~0.20 µM), comparable to or lower than the IC50 of docetaxel or cisplatin. Such cytotoxicity was exerted at a concentration harmless to macrophages (mTHP-1 cells). Besides, the conditioned medium from TA-nanoARC nebulized on A549 cells reduced the expression of the CD204/SRA-1, an M2 phenotype marker, and induced pro-inflammatory activity, comparable to or to a greater extent than that induced by lipopolysaccharide, including IL-6 and TNF-α, in mTHP-1 as a model of tumor-associated macrophages. The endocytosis of TA-nanoARC by A549 cells induced Lysotracker red fluorescence to fade and blur. This suggested the internalization of the highly viscous and ordered TA-nanoARC rich in NAs and subsequent lysosomal dysfunction (and not its antioxidant activity), as responsible for the selective damage on A549 cells. These are the first results showing that nebulized TA-nanoARC, lethal to A549 cells and modulating mTHP-1 cell phenotype, may act as antitumorals in the absence of cytotoxic drugs. Full article

Understanding the molecular structure and water transport behavior in anion-exchange membranes (AEMs) is essential for advancing efficient and cost-effective alkaline fuel cells. In this study, large-scale all-atom molecular dynamics simulations of QPAF-4, a promising AEM material, were performed at multiple water uptakes (λ = 2, 3, 6, and 13). The simulated systems comprised approximately 1.4 to 2.1 million atoms and spanned approximately 26 nm, thus enabling direct comparison with both wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) experiments. The simulations successfully reproduced experimentally observed structure factors, accurately capturing microphase-separated morphologies at the mesoscale ($~$8 nm). Decomposition of the SAXS profile into atom pairs suggests that increasing water uptake may facilitate the aggregation of fluorinated alkyl chains. Furthermore, the calculated pair distribution functions showed excellent agreement with WAXS data, suggesting that the atomistic details were accurately reproduced. The water dynamics exhibited strong dependence on hydration level: At low water uptake, mean squared displacement showed persistent subdiffusive behavior even at long timescales ($~$200 ns), whereas almost normal diffusion was observed when water uptake was high. These results suggest that water mobility may be significantly influenced by nanoconfinement and strong interactions exerted by polymer chains and counterions under dry conditions. These findings provide a basis for the rational design and optimization of high-performance membrane materials. Full article

Geopolymers represent an innovative and environmentally sustainable alternative to traditional construction materials, offering significant potential for reducing anthropogenic CO₂ emissions. Among these, phosphoric acid-activated metakaolin-based systems have attracted increasing attention for their chemical and thermal resilience. In this study, we present a comprehensive structural and mechanical evaluation of metakaolin-based geopolymers synthesized across a wide range of Al/P molar ratios (0.8–4.0). Six formulations were systematically prepared and analyzed using X-ray powder diffraction (XRPD), small-angle X-ray scattering (SAXS), Fourier-transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (ssNMR), and complementary mechanical testing. The novelty of this work lies in the integrated mapping of composition–structure–property relationships across the broad Al/P spectrum under controlled synthesis, combined with the rare application of SAXS to reveal composition-dependent nanoscale domains (~18–50 nm). We identify a stoichiometric window at Al/P ≈ 1.5, where complete acid consumption leads to a structurally homogeneous AlVI–O–P network, yielding the highest compressive strength. In contrast, acid-rich systems exhibit divergent flexural and compressive behaviors, with enhanced flexural strength linked to hydrated silica domains arising from metakaolin dealumination, quantitatively tracked by ²⁹Si MAS NMR. XRPD further reveals the formation of uncommon Si–P crystalline phases (SiP₂O₇, Si₅P₆O₂₅) under low-temperature curing in acid-rich compositions. Together, these findings provide new insights into the nanoscale structuring, phase evolution, and stoichiometric control of silica–alumino–phosphate geopolymers, highlighting strategies for optimizing their performance in demanding thermal and chemical environments. Full article

Thermoresponsive Pluronic hydrogels offer a promising platform for localised antibiotic delivery. However, how drug loading affects the structural integrity and gelation of these systems remains underexplored. This study evaluates the impact of vancomycin on the physicochemical and self-assembly behaviour of Pluronic F127, F108, and F68 hydrogels. Rheological analysis revealed that vancomycin altered the critical micellisation and gelation temperatures (CMT and CGT, respectively), accelerating gelation in weak gel systems but disrupting network formation in stronger gels. Small-angle X-ray scattering (SAXS) showed that vancomycin suppressed micellar ordering, particularly along FCC (111) planes in F127, without inducing a phase transition. Scanning electron microscopy (SEM) imaging confirmed reduced pore integrity in vancomycin-loaded F127 and F108 gels, while 35% F68 gels failed to form stable structures at the tested concentrations despite enhanced drug solubility. F127 (18%) and F108 (22–23%) maintained gelation at 37 °C with reasonable mechanical strength and partial cubic ordering, making them suitable candidates for drug-eluting gels. These findings inform the design of thermoresponsive hydrogels for localised, implant-associated antibiotic delivery. Full article

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that severely impacts motor function, necessitating early detection for effective management. However, current diagnostic methods are expensive and resource-intensive, limiting their accessibility. This study proposes a non-invasive, gait-based screening approach for PD using time-series analysis of video-derived motion data. Gait patterns indicative of PD are analyzed using videos containing walking sequences of PD subjects. The video data are processed via computer vision and human pose estimation techniques to extract key body points. Classification is performed using K-Nearest Neighbors (KNN) and Long Short-Term Memory (LSTM) networks in conjunction with time-series techniques, including Dynamic Time Warping (DTW), Bag of Patterns (BoP), and Symbolic Aggregate Approximation (SAX). KNN classifies based on similarity measures derived from these methods, while LSTM captures complex temporal dependencies. Additionally, Shapelet-based Classification is independently explored for its ability to serve as a self-contained classifier by extracting discriminative motion patterns. On a self-collected dataset (43 instances: 8 PD and 35 healthy), DTW-based classification achieved 88.89% accuracy for both KNN and LSTM. On an external dataset (294 instances: 150 healthy and 144 PD with varying severity), KNN and LSTM achieved 71.19% and 57.63% accuracy, respectively. The proposed approach enhances PD detection through a cost-effective, non-invasive methodology, supporting early diagnosis and disease monitoring. By integrating machine learning with clinical insights, this study demonstrates the potential of AI-driven solutions in advancing PD screening and management. Full article

This paper aims to study the potential of whey, a by-product in the dairy industry, to be used as a sustainable and health-promoting ingredient in baking. In this regard, whey powder (WhF) was produced and incorporated into three composite flours consisting of wheat flour and whey powder in proportions of 5% (WhWF5), 10% (WhWF10), and 15% (WhWF15). These composite flours were then used to produce bread. The nutritional properties (proximate composition, macro and microelement content) and bioactive compounds (total polyphenols and antioxidant activity) were assessed for both the composite flours and the resulting breads. In addition, the rheological behavior of the dough was evaluated using the Mixolab system, while the microstructural characteristics and physical properties of the composite flours were analyzed using Small/Wide Angle X-ray Scattering (SAXS/WAXS) and Fourier Transform Infrared Spectroscopy (FTIR). Sensory evaluation of the breads was also performed. The results demonstrated a positive effect of the whey powder addition on the nutritional profile of both composite flours and bakery products, particularly through increased protein levels (25.24–37.77% in fortified flours vs. 11.26% in control; 16.64–18.89% in fortified breads vs. 14.12% in control) and enhanced mineral content (11.27–80.45% higher compared to white wheat bread), alongside a reduction in carbohydrate content. Bread fortified with 15% whey powder showed higher monolement with increases of 27.80% for K, 7.01% for Mg, and 28.67% for Ca compared to control bread without whey. The analysis of the Mixolab charts confirmed the progressive influence of whey powder on dough rheology. While water absorption remains high, other functional parameters, such as gluten quality, kneading capacity, and starch viscosity, were negatively affected. Nonetheless, the nutritional advantages and reduced retrogradation tendency may offset these drawbacks in the context of developing functional bakery products. Formulations containing 5–10% whey powder appear to offer an optimal balance between technological performance, nutritional quality, and sensory acceptance. Full article

Tumor heterogeneity encompasses genetic, epigenetic, and phenotypic diversity, impacting treatment response and resistance. Spatial heterogeneity occurs both inter- and intra-lesionally, while temporal heterogeneity results from clonal evolution. High-throughput technologies like next-generation sequencing (NGS) enhance tumor characterization, but conventional biopsies still do not adequately capture genetic heterogeneity. Liquid biopsy (LBx), analyzing circulating tumor DNA (ctDNA), provides a minimally invasive alternative, offering real-time tumor evolution insights and identifying resistance mutations overlooked by tissue biopsies. This study evaluates the capability of LBx to capture tumor heterogeneity by comparing genetic profiles from multiple metastatic lesions and LBx samples. Eight patients from the Augsburger Longitudinal Plasma Study with various types of cancer provided 56 postmortem tissue samples, which were compared against pre-mortem LBx-derived circulating-free DNA sequenced by NGS. Tissue analyses revealed significant mutational diversity (4–12 mutations per patient, VAFs: 1.5–71.4%), with distinct intra- and inter-lesional heterogeneity. LBx identified 51 variants (4–17 per patient, VAFs: 0.2–31.1%), which overlapped with mutations from the tissue samples by 33–92%. Notably, 22 tissue variants were absent in LBx, whereas 18 LBx-exclusive variants were detected (VAFs: 0.2–2.8%). LBx effectively captures tumor heterogeneity, but should be used in conjunction with tissue biopsies for comprehensive genetic profiling. Full article

Background: Local anesthesia is essential for most dental procedures, but its parenteral administration is often painful. Topical anesthetics are commonly used to minimize local anesthesia pain; however, commercial formulations fail to fully prevent the discomfort of local anesthetic injection. Methods: We developed and characterized a novel lidocaine and epinephrine co-loaded liquid crystalline precursor system (LCPS) for topical anesthesia. The formulation was structurally characterized using polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS). Rheological behavior was assessed through continuous and oscillatory rheological analyses. Texture profile analysis, in vitro mucoadhesive force evaluation, in vitro drug release and permeation studies, and an in vivo toxicity assay using the chicken chorioallantoic membrane (CAM) model were also conducted. Results: PLM and SAXS confirmed the transition of the LCPS from a microemulsion to a lamellar liquid crystalline structure upon contact with artificial saliva. This transition enhanced formulation consistency by over 100 times and tripled mucoadhesion strength. The LCPS also provided controlled drug release, reducing permeation flow by 93% compared to the commercial formulation. Importantly, the CAM assay indicated that the LCPS exhibited similar toxicity to the commercial product. Conclusions: The developed LCPS demonstrated promising physicochemical and biological properties for topical anesthesia, including enhanced mucoadhesion, controlled drug delivery, and acceptable biocompatibility. These findings support its potential for in vivo application and future clinical use to reduce pain during dental anesthesia procedures. Full article

The recent discovery of Orthonairovirus songlingense (SGLV) and Norwavirus beijiense (BJNV) in China has raised significant concern due to their potential to cause severe human disease. However, little is known about the structural features and function of their nucleoproteins, which play a key role in the viral life cycle. By combining small-angle X-ray scattering (SAXS) data and AlphaFold 3 simulations, we reconstructed the BJNV and SGLV nucleoprotein structures for the first time. The SGLV and BJNV nucleoproteins have structures that are broadly similar to those of Orthonairovirus haemorrhagiae (CCHFV) nucleoproteins despite low sequence similarity. Based on structural analysis, several residues located in the positively charged region of BJNV and SGLV nucleoproteins have been indicated to be important for viral RNA binding. A positively charged RNA-binding crevice runs along the interior of the SGLV and BJNV ribonucleoprotein complex (RNP), shielding the viral RNA. Despite the high structural similarity between SGLV and BJNV nucleoprotein monomers, their RNPs adopt distinct conformations. These findings provide important insights into the molecular mechanisms of viral genome packaging and replication in these emerging pathogens. Also, our work demonstrates that experimental SAXS data can validate and improve predicted AlphaFold 3 structures to reflect their solution structure and also provides the first low-resolution structures of the BJNV and SGLV nucleoproteins for the future development of POC tests, vaccines, and antiviral drugs. Full article

The effect of annealing on the microstructure and tensile properties of low-density polyethylene (LDPE) non-woven fabric produced by melt electrospinning was systematically investigated using DSC, SAXS, SEM, etc. The results showed that, above an annealing temperature of 80 $°\mathrm{C}$, both the main melting point and crystallinity of LDPE decreased compared to the original sample, as did the tensile strength of the non-woven fabric. Additionally, the lamellar distribution became broader at annealing temperatures above 80 $°\mathrm{C}$. The recrystallization mechanism of molten lamellae (disordered chains) in LDPE was elucidated by fitting the data using a Gaussian function. It was found that secondary crystallization, forming thicker lamellae, and spontaneous crystallization, forming thinner lamellae, occurred simultaneously at rates dependent on the annealing temperature. Secondary crystallization dominated at temperatures ≤80 $°\mathrm{C}$, whereas spontaneous crystallization prevailed at temperatures above 80 $°\mathrm{C}$. These findings explain the observed changes in the microstructure and tensile properties of the LDPE non-woven fabric. Furthermore, a physical model describing the microstructural evolution of the LDPE non-woven fabric during annealing was proposed based on the experimental evidence. Full article