Search Results (372)

This study investigates the influence of conventional textile pretreatment and periodate oxidation parameters on the structural modifications and functional properties of woven cotton fabrics. Unlike most studies focused on cellulose pulps or isolated textile fibers, the present work examines how the initial structural state of the textile substrate, determined by its pretreatment history, governs the oxidation pathways. Cotton fabrics were subjected to alkaline scouring (SC), hydrogen peroxide bleaching (BC), and combined scouring–bleaching (SBC), followed by sodium periodate oxidation under controlled conditions. Carbonyl species were quantified analytically and identified by ATR-FTIR spectroscopy, while structural changes were evaluated by X-ray diffraction (XRD). Mechanical properties were assessed using the normalized parameters (Fa/Fa₀ and E/E₀), hydrophilicity by water absorption capacity (WAC), and optical stability by the yellowness index (YI). The results demonstrated that the pretreatments influence the oxidant accessibility and the balance between carbonyl speciation. XRD analysis shows a moderate decrease in crystallinity, indicating partial preservation of the crystalline domains, whereas mechanical properties decrease significantly (35–65%), concomitant with a 25–45% reduction in WAC. These results suggest that the impairment in mechanical and hydrophilic properties is primarily governed by localized C2–C3 bond scission, secondary oxidative reactions, and supramolecular rearrangements, rather than by bulk crystalline loss. The oxidized SC series exhibits higher YI values associated with an increased free aldehyde content, while the BC and SBC fabrics show improved optical stability. Overall, these results demonstrate that pretreatment history governs periodate oxidation pathways and establishes clear structure–property relationship relevant for the controlled functionalization of woven cotton fabrics. Full article

Aluminum–silicon (Al-Si) alloys are widely used in aerospace, automotive manufacturing, power electronics, marine engineering and other fields due to their excellent physical properties. However, their corrosion resistance is insufficient in harsh service environments. In this study, a variety of characterization methods were adopted, including scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical measurements (electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization), immersion corrosion tests, and scanning vibrating electrode technique (SVET). The results show that the appropriate heat treatment regime can significantly enhance the corrosion resistance of the alloy, while improper aging parameters will aggravate the corrosion tendency. The optimal heat treatment regime is solution treatment at 500 °C for 4 h followed by aging at 200 °C for 48 h. Under this condition, the corrosion current density (i_corr) is as low as 79.30 μA/cm², and the low-frequency impedance modulus and phase angle in EIS tests are optimal. The as-extruded alloy exhibits severe localized corrosion, while the heat-treated alloy transforms into mild and uniform corrosion. The underlying mechanism is that heat treatment induces the formation of uniformly distributed nanoscale Mg₂Si and Al₃(Sc,Zr) precipitates, which synergistically improve the corrosion resistance of the alloy by weakening micro-galvanic coupling and facilitating the formation of a stable passive film. Full article

Objective: In this work, we look at Hansen solubility parameters (HSPs) to predict drug miscibility with polymers, in order to create a saturated amorphous drug phase. Methods: We used the Yamamoto molecular break (Y-MB) group contribution method (GCM) and solvent experiments to establish HSPs for PLA and 12 model drugs. Drug-loaded samples were made using solvent casting (SC) and vacuum compression moulding (VCM) in incremental drug concentrations until a saturated amorphous drug load was achieved. The amorphous drug phase was confirmed by X-ray diffraction after 24 h. These amorphous samples were further analysed by HPLC to confirm drug concentration. These drug concentrations were expressed as volume concentration in PLA, and they correlate with linearised HSP distance between drug and polymer. Results: This gives a statistically significant linear correlation between drug concentration and HSPs with R² values ranging from 0.85 to 0.93 for SC and VCM methods. Conclusions: This work entails a possible concept for novel application of HSPs to predict miscible drug–polymer pairs and to estimate amorphous saturation concentration. Full article

The red resin of Dracaena cochinchinensis (Lour.) S.C. Chen, known as Chinese dragon’s blood, is formed through metabolic reprogramming following trunk injury, during which the original steroidal saponins are depleted and transformed. To investigate the steroidal degradation intermediates in this process, a systematic phytochemical study was conducted on the resin from Yunnan Province, leading to the isolation of 14 steroidal constituents (2 new and 12 known). The two new compounds, dracaenogenins C (1) and D (2), were identified as rare 12(13→14)-abeo-spirostanol aglycones, with 2 representing an unusual C-14α-hydroxylated derivative. Their structures, including absolute configurations, were unambiguously determined by comprehensive spectroscopic analysis (1D and 2D NMR, HRESIMS) and single-crystal X-ray diffraction. Biogenetic analysis suggests that these unusual aglycones arise from the acid-catalyzed Wagner–Meerwein rearrangement of diosgenin-type saponins via C-18 angular methyl migration (C-10→C-13) and C-ring contraction, serving as rare catabolic intermediates trapped during the metabolic shift from saponin accumulation to polyphenol biosynthesis. Furthermore, cytotoxicity evaluation against HepG2 cells revealed that while the parent glycosylated saponins (e.g., dioscin and gracillin) exhibited significant toxicity, the rearranged aglycones (1, 2, and 3) and other degradation products were devoid of cytotoxicity, supporting a detoxification mechanism during resin formation. Full article

The Wailukum area in North Maluku Province, Indonesia, is an ultramafic rock complex with a high degree of serpentinization. The mineral composition of ultramafic and mafic rocks strongly influences the distribution and enrichment of scandium (Sc) during lateritization. In this study, we aim to analyze three types of geological materials in a lateritic profile that contains Sc, specifically bedrock, saprolite, and limonite, in terms of element distribution, mineral composition, and rock identification. We used the analytical methods of petrography, X-ray diffraction (XRD), X-Ray Fluorescence (XRF), and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES). The results show that Sc in bedrock is mainly associated with clinopyroxene minerals such as augite and diopside. In saprolite, Sc content decreases due to higher mobility but remains partly associated with clinopyroxene, and in limonite zone, Sc reaches maximum enrichment. Among rock types, gabbro contains the highest absolute Sc concentration (23.25 ppm in bedrock and up to 58.5 ppm in limonite), while wehrlite records the greatest enrichment ratio, with a 9.18-fold increase from bedrock to limonite. By contrast, gabbro shows the lowest enrichment ratio (2.52-fold) despite its high initial Sc content. These patterns indicate that Sc enrichment is controlled by clinopyroxene as the primary host in bedrock, affecting its relative stability during weathering. Full article

This paper presents the compositional characterisation of obsidian artefacts from the archaeological site of Maddalena di Muccia (Marche, Central Italy). The assemblage, spanning the Early Neolithic to the Copper Age, was chemically and petrographically investigated using two non-destructive X-ray analytical instruments: a wavelength-dispersive X-ray spectrometer and a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. Geochemical data allow secure attribution of the artefacts to their geological sources, confirming the predominant use of Palmarola obsidian during the Early Neolithic and documenting the continued circulation of obsidian also from other sources (Lipari and Monte Arci) into the Copper Age. Significantly, the Muccia assemblage provides the first evidence in the Adriatic area for the contemporaneous presence of multiple Monte Arci obsidian sub-sources (S.A. and S.C.). This compositional pattern suggests sustained long-term exchange networks involving obsidian, and highlights the role of central Adriatic sites within broader prehistoric interaction systems of the central Mediterranean. Full article

Scandium (Sc), when added together with magnesium (Mg), forms a highly effective synergistic pair in aluminum (Al) alloys, enhancing their performance in various applications. While the thermomechanical processing and heat treatment of such Al-Mg-Sc alloys have been well investigated, the behavior and features of their as-cast state remain less understood. In particular, the evolution of cellular/dendritic microstructures and the formation of phases at submicrometric and nanometric scales, especially those developing during solid-state cooling, require further elucidation. The present study employs a combination of conventional and advanced characterization techniques in the Al-5 wt.%Mg-0.4 wt.% Sc alloy, including CALPHAD, optical microscopy, scanning electron microscopy (SEM), transmission and scanning transmission electron microscopy (TEM/STEM) with energy-dispersive spectroscopy (EDS), x-ray diffractometry (XRD), tensile testing, and fractographic analysis. Al-rich dendrites surrounded by Al₃Sc, AlFe, and β-Al₃Mg₂ phases and the formation of primary submicrometric clusters containing AlFe and Al₃Sc have been identified, revealing important microstructural features that depend strongly on the solidification conditions. Moreover, nanometric Al₃Sc precipitates mainly in the form of rod-like structures with sizes in the order of 50–200 nm have been observed within the α-Al matrix during solid-state cooling stage. At higher solidification rates, such as 15.3 °C/s, these precipitates remain predominantly in solid solution, indicating strong solidification rate dependence in the precipitation behavior. Comparisons between alloys containing 0.1 Sc and 0.4 Sc have demonstrated that the morphology, size, and distribution of Sc-rich phases significantly affect the stress–strain tensile response and underlying strengthening mechanisms. Distinct Portevin–Le Chatelier (PLC) effects have been observed, corresponding to very different serration activities in the stress–strain curves comparing both Al-5%Mg-0.4%Sc and Al-5%Mg-0.1%Sc alloy samples. Among the compositions and conditions studied, the Al–5Mg–0.4Sc alloy samples solidified under the fast-cooling condition (11.2 °C/s) exhibited the most improved mechanical performance, attaining a strength of 306 MPa and an elongation of 22.6%, underscoring the pivotal role of Sc content and solidification rate in achieving optimized mechanical properties. Full article

Radiomics promises quantitative biomarkers extracted from routine hip imaging to support diagnosis, prognosis, and surgical planning, but current evidence is fragmented across pathologies, modalities, and computational pipelines. We conducted a scoping review following PRISMA-ScR and the Population–Concept–Context framework, including peer-reviewed original studies on adults (≥18 years) that applied radiomics or deep-radiomics to hip imaging (X-ray, CT, MRI, DEXA) with clinically relevant outcomes. PubMed (MEDLINE), Embase and Scopus (Elsevier) were searched from 1 January 2021 to 30 August 2025 and complemented by snowballing; screening and data charting were performed in duplicate. Given heterogeneity, findings were synthesized narratively by a priori clusters. In fragility/osteoporosis, opportunistic CT and radiograph-based models frequently achieved AUCs around 0.90–0.96, while DXA-radiomics added information beyond bone mineral density/FRAX and trabecular MRI provided complementary microarchitectural signals. For osteonecrosis of the femoral head, multisequence MRI enabled early diagnosis with AUCs > 0.94; radiomics differentiated transient bone marrow edema with AUCs~0.92–0.94 and predicted collapse using radiographs or MRI with AUCs~0.85–0.90, including automated pipelines with external validation around 0.85. In femoroacetabular impingement, 3D Dixon-MRI studies reported very high performance (~0.97–1.00) with preliminary multicenter generalizability and added value from periarticular soft-tissue features. In total hip arthroplasty, radiomics anticipated press-fit cup stability from preoperative radiographs (AUC~0.82) and predicted 6-month functional recovery using clinico-radiomic CT models (AUC~0.95). Across clusters, methodological robustness was variable (sample sizes, harmonization, leakage control, external/temporal validation, calibration, clinical utility). Radiomics for adult hip disorders shows tangible translational promise in opportunistic screening, complex differential diagnosis, and perioperative decision support, but broader clinical adoption will require multicenter datasets, IBSI-aligned standardization, transparent reporting of calibration and decision-curve analyses, and prospective validation. Full article

The Esquel pallasite provides a valuable record of metal–silicate interaction in differentiated planetesimals, yet many aspects of its formation and thermal evolution remain uncertain. Here, we present a comprehensive multi-technique characterization of a single Esquel specimen, integrating SC-XRD, Raman spectroscopy, SEM–EDS, XPS, magnetic force microscopy, and X-ray computed tomography. Olivine grains are shown to be structurally pristine, with the first full crystallographic refinement for Esquel confirming a single-domain silicate lattice. XPS demonstrates a stoichiometric silicate surface containing only lattice O²⁻, Si⁴⁺, Mg²⁺, and Fe²⁺, indicating that olivine remained chemically unaltered. The Fe–Ni metal preserves diffusion-controlled taenite–kamacite exsolution, compositionally distinct plessite, accessory schreibersite and troilite as resolved by SEM. Quantitative Ni zoning, evaluated through interface-to-center gradients and a width–center-Ni correlation method, yields a self-consistent cooling rate of ~10–20 °C/Myr. MFM reveals microscale magnetic structures that correlate directly with Fe–Ni chemical zoning, providing magnetic confirmation of slow cooling. CT analysis further identifies interconnected metal networks, inclusions, and micro-porosity reflecting melt migration and late-stage modification. These results establish Esquel as an exceptionally well-preserved pallasite and demonstrate the value of integrated, multi-scale analytical workflows for reconstructing early Solar System processes. Full article

We report the first examples of bent-shaped LC dimers based on a seven-membered bridged stilbene. We synthesized nonylene- and ether-linked cyano-terminated dimers (sC9-tCN and sOC7O-tCN, respectively) and a homologous series of nonylene-linked alkyl-terminated dimers (sC9-tCn) with alkyl carbon atoms n = 1–6. Polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction measurement were employed to investigate the phase-transition behavior and LC phase structures. sC9-tCN and sOC7O-tCN only exhibited a nematic (N) phase, whereas sC9-tCn (n = 1–5) formed both the N_TB and N phases. sC9-tC5 additionally formed an unidentified X phase from the N_TB phase and sC9-tC6 exhibited a smectic A phase from the N phase. The weak dispersion force and intermolecular affinity provided by the terminal alkyl chains are likely to be preferable to the large dipole–dipole interactions by the cyano termini for the N_TB phase formation of the present dimers. The isotropic points of sC9-tCn showed an odd–even oscillation with n, whereas the N–N_TB phase transition temperatures were comparable. Remarkably, the N_TB stripe textures of sC9-tCn appeared perpendicular to the rubbing direction, and the N–N_TB phase transitions exhibited their second-order nature. This study revealed the unique N_TB phase properties of the 7-membered bridged stilbene-based LC dimers. Full article

9,10-Disila-9,10-dihydroanthracenes have attracted significant attention due to their unique electronic structures, characterized by an extended π-system facilitated by σ-π conjugation. Here, we report the synthesis of 9,10-bis(p-methoxyphenyl)-9,10-disila-9,10-dihydroanthracene, which serves as a crucial precursor for the preparation of the corresponding difluoro derivative. This conversion is achieved through a selective deanisyl-fluorination at the silicon centers using HBF₄. A key finding is the successful isolation of the cis-isomer of 9,10-difluoro-9,10-disila-9,10-dihydroanthracenes as a crystalline compound. This allowed for definitive structural characterization by single-crystal X-ray diffraction (SC-XRD) analysis, providing precise geometric insights into this electronically fascinating framework. Full article

Tetranuclear rhodium carbonyl clusters are vital catalytic precursors; yet derivatives featuring bidentate phosphines are less common, due to the propensity for cluster fragmentation during synthesis. This study reports the successful isolation of five new heteroleptic species by reacting Rh₄(CO)₁₂ with various bidentate diphosphines under homogeneous conditions and at room temperature, namely the mono-substituted Rh₄(CO)₁₀(dppe) (1) and Rh₄(CO)₁₀(dppb) (3), the rare bis-substituted derivative Rh₄(CO)₈(dppe)₂ (2), and the two unique dimeric assemblies {Rh₄(CO)₁₀(dpp-hexane)}₂ (4) and {Rh₄(CO)₁₀(trans-dppe)}₂ (5). The tetrahedral Rh₄ core of the cluster precursor was preserved in all cases. The new compounds were characterized via infrared (IR) spectroscopy and single-crystal X-ray diffraction (SC-XRD). Furthermore, variable-temperature (VT) ³¹P{¹H} NMR spectroscopy elucidated the dynamic behavior of the phosphorus atoms. This work reports a robust methodology for accessing stable, low-nuclearity rhodium phosphine clusters with tunable properties. Full article

The YbBO₃–ScBO₃ system was studied across the selected compositional range by means of solid-state synthesis, powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and photoluminescence spectroscopy. XRD of annealed samples at 1300–1400 °C revealed that the system reaches equilibrium and consists of two phases, YbBO₃ and ScBO₃, separated by a two-phase region. The lattice parameters show a limited solubility between Yb³⁺ and Sc³⁺ ions. DSC measurements display a broad endothermic feature at approximately 1480 °C, corresponding to the eutectic point. Near-infrared emission excited at 975–980 nm originates from Yb³⁺ ions and shows the highest intensity for pure YbBO₃ and for the Sc-rich composition, while intermediate samples exhibit weaker luminescence. Full article

Pyrimethamine (PYR), a drug approved for the treatment of infections caused by protozoan parasites, is a multifunctional API based on 2,4-diaminopyrimidine scaffold. The present study aims toward the development of novel solid forms of PYR, by combining it with three isomeric aminobenzoic acids—2-aminobenzoic acid (2NH₂-BA), 3-aminobenzoic acid (3NH₂-BA), and 4-aminobenzoic acid (4NH₂-BA). Solution crystallization led to the formation of three new solvated salts of PYR (PYR/2NH₂-BA/EtOH/H₂O, PYR/3NH₂-BA/EtOH, and PYR/4NH₂-BA/EtOH/H₂O). The detailed physicochemical properties of the formed compounds were characterized by single-crystal X-ray diffraction (SC-XRD), FTIR, PXRD, thermogravimetry (TG), and differential scanning calorimetry (DSC). Additionally, the pre-crystallization solutions of PYR with 2NH₂-BA, 3NH₂-BA, and 4NH₂-BA were studied by electrospray ionization mass spectrometry technique (ESI-MS), which enabled the observation of peaks corresponding to noncovalently bonded molecules, providing insight into their specific aggregation in a solution/gas phase environment. We identified different non-covalent aggregates, including self-aggregates of aminobenzoic acids and PYR/aminobenzoic acid associates of different stoichiometries. Full article

Objectives: This study evaluated and compared the sealing ability and elemental composition of a resin-based endodontic sealer (AH Plus) used with three root canal obturation techniques: single cone (SC), lateral compaction (LC), and warm vertical condensation (WVC). The investigation focused on microstructural characteristics, interfacial integrity, and elemental distribution within filled root canals. Material and Methods: Sixty extracted single-root teeth were instrumented using the ProTaper Gold system and randomly assigned to three groups (n = 20) according to the obturation technique. The AH Plus Jet sealer was applied in all cases. Following obturation, samples were subjected to radiographic investigation and analyzed using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) to assess the sealing performance and chemical composition. Results: Radiographic and microscopic assessments indicated that the SC method showed strong gutta-percha adhesion to dentin with a thin cement layer, whereas WVC provided excellent adaptation and penetration of gutta-percha. The LC technique demonstrated good adhesion but displayed occasional structural irregularities. SC has the thicker adhesion layer with uneven distribution regarding coronal, median, and apical, regions ranging from 45 to 80 μm, while WVC ensures a thin and uniform sealing layer of about 35 μm in all regions. SEM and EDX analyses detailed the interfacial microstructure and confirmed the presence of carbon (C), oxygen (O), calcium (Ca), zinc (Zn), barium (Ba), and sulfur (S) across all groups. Conclusions: All three obturation techniques (SC, WVC, LC) achieved effective sealing when combined with the AH Plus sealer. The main difference between the methods consists of the sealer layer thickness and its even distribution regarding gutta-percha cones. Full article