Search Results (1,924)

Background/Objectives: Provisional restorations are essential in prosthodontic treatment, and reliable intraoral repair is clinically important during extended interim use. This in vitro study evaluated the effects of organic solvent pretreatment on surface characteristics and shear bond strength (SBS) of CAD/CAM provisional restorative materials fabricated by milling, stereolithography (SLA), and digital light processing (DLP). Methods: Three materials were assigned to five surface treatment conditions: no solvent (control), isopropyl alcohol (IPA), tetrahydrofuran (THF), acetonitrile (ACN), and pyridine (PYR). After pretreatment, separate specimens were used for surface analysis and SBS testing. Surface roughness was measured by atomic force microscopy using arithmetic mean height (S_a) and root mean square height (S_q), and surface morphology was examined by scanning electron microscopy (SEM). For SBS testing, specimens were repaired using a universal adhesive and a flowable resin composite, followed by failure mode analysis. Data were analyzed using two-way ANOVA and Tukey’s post hoc test (α = 0.05). Results: Material type, solvent treatment, and their interaction significantly affected SBS, S_a, and S_q. The DLP material showed the highest SBS overall, with no significant differences among treatments. In the SLA material, ACN resulted in the lowest SBS, whereas PYR showed the highest mean value. In the milled material, THF, ACN, and PYR produced significantly higher SBS than the control and IPA groups. Conclusions: Within the limitations of this study, the effect of organic solvent pretreatment on repair performance was substrate-dependent. Full article

Cocoa husk tea has gained attention as a value-added beverage from cocoa processing by-products, due to its potential content of bioactive compounds associated with health benefits. However, rapid and reliable analytical methods for the simultaneous determination of methylxanthines and flavanols in this matrix remain limited. This study aimed to develop and validate a rapid HPLC–PDA method for the simultaneous determination of methylxanthines and selected flavanols in cocoa husk tea. Separation was performed using a Zorbax 300SB-C18 with a gradient system of acetic acid, water and acetonitrile, and detection at 280 nm. The method enabled separation of theobromine, caffeine, catechin, epicatechin, procyanidin B1, and procyanidin B2 within 15 min. Validation followed ICH Q2(R2) guidelines, demonstrating satisfactory linearity, sensitivity, accuracy, and precision. The method was applied to ten commercial cocoa husk tea products from Thailand. Theobromine was the predominant methylxanthine (10.483–16.027 mg g⁻¹), whereas caffeine was lower (0.923–1.909 mg g⁻¹), while flavanol contents varied among samples. These findings demonstrate that the developed method provides a rapid and reliable approach for the analysis and quality assessment of cocoa husk tea products and may support the further utilization of cocoa by-products in the functional beverage industry. Full article

Ulcerative colitis is a chronic inflammatory bowel disease that requires new treatment approaches beyond traditional anti-inflammatory drugs. In this study, we analyzed publicly available single-cell RNA sequencing data from a DSS-induced colitis mouse model and identified pyroptosis as a key biological process linked to epithelial damage. Based on this, we screened marine-derived brominated indoles for potential pyroptosis inhibitors and identified 6-bromoindole-3-acetonitrile as a promising candidate. Our results show that this compound significantly alleviates DSS-induced colitis in mice, with notable body weight recovery and a drop in Disease Activity Index (DAI) scores from about 8.5 to below 4 (p < 0.05). At the molecular level, it lowers the mRNA levels of Nlrp3, Caspase-1, and other pyroptosis-related genes, indicating suppression of the pyroptotic pathway. Moreover, treatment helps restore the intestinal barrier by supporting goblet cell regeneration and strengthening tight junctions. Molecular docking suggests that 6-bromoindole-3-acetonitrile binds stably to the active site of myeloperoxidase (MPO), with a binding energy of −18.1 kcal/mol, offering a possible structural basis for its anti-inflammatory effects. Together, these findings point to a marine-derived compound that reduces both inflammation and pyroptosis, representing a promising strategy for treating ulcerative colitis. Notably, these results come from preclinical studies and need further validation in clinical settings. Full article

Rechargeable magnesium batteries are promising candidates for next-generation energy storage systems due to their intrinsic safety, natural abundance, and high volumetric capacity. However, their practical application remains limited by sluggish Mg²⁺ transport, electrolyte instability, and low cathode utilization. In this work, a halogen-free electrolyte (HFE) based on Mg(NO₃)₂ in an acetonitrile/tetraethylene glycol dimethyl ether (ACN/G4) solvent system is modified using the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) to form HFE_IL, with the aim of enhancing ionic transport and interfacial stability. In parallel, a sustainable sulfur cathode integrated with microalgae-derived hard carbon (S_C) is developed to improve electronic conductivity and suppress polysulfide shuttling. Structural and spectroscopic analyses confirm that the incorporation of the ionic liquid preserves the electrolyte framework while tuning the solvation environment. Electrochemical characterization (EIS, CV, LSV, GCD, and Mg stripping/plating measurements) reveals that HFE_IL exhibits reduced bulk and interfacial resistances, a significantly lower activation energy (0.0173 eV compared to 0.14 eV), and an increased Mg²⁺ transference number (~0.8). Furthermore, enhanced Mg²⁺ diffusion (~10⁻¹³ cm² s⁻¹) and improved charge-transfer kinetics are achieved compared to the pristine electrolyte. Symmetric Mg‖Mg cells demonstrate stable stripping/plating behavior with reduced polarization over 100 h. In full Mg‖electrolyte‖S_C cells, the HFE_IL system delivers a higher discharge capacity (~575 mAh g⁻¹) compared to the pristine electrolyte (~437 mAh g⁻¹), indicating improved reversibility and Mg²⁺ utilization. This study demonstrates that ionic-liquid modification of halogen-free electrolytes, combined with sustainable carbon–sulfur cathodes, provides an effective strategy to enhance Mg²⁺ transport, interfacial stability, and overall electrochemical performance in magnesium batteries. Full article

The combination of gemcitabine (GEM) and olaparib (OLA) shows promise for treating pancreatic cancer, particularly in patients with mutations in the BRCA genes. This work presents the validation of a straightforward, fast, and sensitive chromatographic method for the simultaneous analysis of GEM and OLA, supporting the development of advanced pharmaceutical formulations that combine the two drugs. The efficient chromatographic separation of GEM and OLA was achieved using a C18 column (250 × 4.6 mm, 5 μm) with a mobile phase composed of acetonitrile and water (50:50, v/v), which eluted isocratically at a flow rate of 0.8 mL/min. Determinations were performed using a PDA detector at 243 nm for both drugs. The retention times for GEM and OLA were approximately 3.3 and 4.3 min, respectively. The method was linear (R² > 0.999), with a regression curve in the concentration range of 0.5 to 10.0 μg/mL, demonstrating sensitivity, precision, and accuracy. The recovery rates of the drugs from the pancreatic tissue were higher than 97.0%. The components of a coated liposomal formulation and the pancreatic tissue did not interfere with the analysis, and both drugs demonstrated a low degradation rate under stressful conditions. In conclusion, the validated method was suitable for quantifying GEM and OLA simultaneously, even in a biological matrix, making it feasible to support the development of advanced pharmaceutical formulations that incorporate both drugs, such as liposomes. Full article

Electrochemical exfoliation is an efficient approach for producing MoS₂ nanosheets, yet the correlation between exfoliation conditions, structural evolution, and nonlinear optical (NLO) properties remains insufficiently understood. In this work, MoS₂ nanosheets were prepared using two representative electrolyte systems, acetonitrile/TPABr and aqueous Na₂SO₄, under controlled voltages. The results reveal distinct exfoliation mechanisms, where ion intercalation dominates in the nonaqueous system, while bubble-assisted processes prevail in the aqueous system. Structural and chemical analyses (Raman, XRD, EDS, and XPS) demonstrate that the nonaqueous system yields MoS₂ with higher crystallinity and lower oxidation degree, whereas the aqueous system shows increased oxidation with the coexistence of Mo⁵⁺ and Mo⁶⁺ species. Correspondingly, enhanced nonlinear absorption and optical limiting performance are observed. A clear mechanism–structure–property relationship is established, highlighting the critical role of electrolyte environment and applied voltage in tailoring NLO responses. This work provides insights into the controlled preparation of MoS₂ nanosheets for photonic and optoelectronic applications. Full article

Crude fidaxomicin contains difficult-to-separate impurities, and conventional dual-step purification usually requires intermediate concentration and transfer, which increases process complexity and may aggravate product loss or degradation. To address this challenge, this study exploits the complementary selectivity of methanol/water (80/20, v/v) and acetonitrile/water (70/30, v/v) binary mobile phases and proposes two purification processes based on step-gradient twin-column recycling chromatography, namely spatial integration and system integration. In the spatial integration strategy, dual-stage separations that are conventionally performed in separate chromatographic systems are sequentially integrated into a single twin-column recycling system in combination with on-line heart-cutting, thereby eliminating intermediate off-line processing steps. In contrast, the system integration strategy merges the two binary mobile phases in defined proportions to construct a single ternary mobile phase composed of methanol/acetonitrile/water (37.5/37.5/25, v/v/v), enabling one-step complete separation. The results demonstrate that the spatial integration strategy, employing binary mobile-phase switching, produces fidaxomicin with a purity of 99.9%, recoveries ranging from 75.27% to 78.77%, and productivities ranging from 307.22 to 328.82 g·L⁻¹·day⁻¹, regardless of the switching sequence. The system integration strategy, based on one-step elution with the ternary mobile phase, achieves the same product purity of 99.9% without mobile-phase switching, with a recovery of 70.41% and a productivity of 246.33 g·L⁻¹·day⁻¹. These results confirm the applicability and flexibility of both integrated strategies for fidaxomicin purification, while indicating that the spatial integration strategy provides better overall preparative performance and the system integration strategy offers a simpler one-step operation. Full article

Accurate profiling of amino acids and selenoamino acids is crucial for evaluating the nutritional quality of selenium-enriched crops. To provide a reliable and accessible tool for routine food monitoring, this study employed pre-column derivatization high performance liquid chromatography (HPLC) method for the simultaneous determination and compositional analysis of 17 standard amino acids, selenocystine (SeCys₂), and selenomethionine (SeMet) in various organs of selenium-enriched radish. Chromatographic separation was performed using a C18 column and a mobile phase of sodium acetate buffer (pH 5.25) and acetonitrile under gradient elution, with diode array detection (DAD) at 360 nm. Method validation demonstrated excellent linearity (R²) ≥ 0.995 for all 19 amino acids within their tested ranges. The limits of detection (LODs) and limits of quantitation (LOQs) were 0.06 to 0.21 mg/L and 0.19 to 0.68 mg/L, respectively. The spike recoveries ranged from 88.2% to 101.7%, while the intra-day and inter-day relative standard deviations (RSDs) were ≤3.09% and ≤4.25%, respectively. The levels of total, essential, selenoamino and taste-active amino acids in the leaves exceeded those in the taproot, with the highest total content of 2398.41 mg/kg found in leaves at the primary growth stage of the taproot. The total content of selenoamino acids ranged from 2.65 to 6.78 mg/kg. This method enables the simultaneous quantification of various amino acids, including selenoamino acids, in different organs of selenium-enriched radish throughout its entire growth period, providing a theoretical basis for the development of selenium-fortified products. Full article

Graphene-based composite materials have attracted much attention for a range of applications in various fields, including electronics, sensing, catalysis, energy storage and conversion. Single-step large-scale microwave plasma synthesis of graphene and nitrogen-doped graphene (N-graphene) composite materials has been demonstrated. The developed atmospheric pressure plasma method allows continuous synthesis of different graphene-based hybrids in a controllable and environmentally friendly manner. Control over the synthesis process, i.e., size, uniformity, surface distribution of the nanoparticles and graphene/N-graphene quality, was provided by adjusting plasma parameters and injection configuration. Protocols for the production of particular composites, i.e., graphene-MnO, N-graphene-MnO, N-graphene-MnS, and N-graphene-Fe_xO_y, have been established using methane and acetonitrile as precursors. A comprehensive physicochemical characterization of the produced composites was conducted using high-resolution transmission electron microscopy, scanning transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and near-edge X-ray-absorption fine-structure and X-ray photoelectron spectroscopies. Full article

Ceftobiprole is a fifth-generation beta-cephalosporin with high inter-individual pharmacokinetic variability in critically ill patients. However, data on its pharmacokinetics and central nervous system (CNS) penetration are limited. This study developed and validated a rapid LC-MS/MS method for quantifying ceftobiprole in human plasma and CSF. Sample preparation involved protein precipitation of 50 µL aliquots. Analysis used gradient elution on an ACQUITY UPLC^® HSS T3 column (2.1 × 100 mm, 1.8 µm) with 0.2% formic acid and acetonitrile and was detected by positive ion electrospray, achieving a 3.5 min run time. The method was linear from 0.100 to 25.0 mg/L in plasma and 0.0500 to 15.0 mg/L in CSF. Intra- and inter-run precision and accuracy were within ±15% at all quality control levels. All validation parameters, including selectivity, matrix effects, recovery, and stability under various conditions, met acceptance criteria. Potential interference from the prodrug ceftobiprole medocaril was evaluated and found to be negligible. The method was successfully applied to samples from three patients, revealing a CSF penetration range of 11.9% to 36.5%. This validated LC-MS/MS method enables simple and rapid quantification of ceftobiprole in plasma and cerebrospinal fluid, filling the gap in data on its CNS penetration and supporting routine drug concentration monitoring in critically ill patients. Full article

The spontaneous reduction of one Cu(II) center to Cu(I) in a series of three dinuclear copper complexes in acetonitrile is described. These complexes feature ligands that include nitrogen donors from a diazecine ring and imidazole, designated as promeim, thiopromeim, and thioenmeim; the latter two incorporate a thioether as a third donor component. The mechanism of metal reduction was elucidated through spectroscopic and spectrometric techniques (UV-vis, EPR, XANES, ESI-MS) and electrochemical tools, in combination with DFT electronic structure calculations. Based on these and on spectroelectrochemical results, a mechanism is proposed in which the one-electron reduction of one of the copper ions is achieved by a one-electron oxidation in the adjacent imidazole group, while the other copper ion remains as Cu(II). The persistent detection of superoxide and peroxide over long periods suggests a mechanism in which a catalytic cycle involving electron transfer occurs between copper, ligand, and dioxygen. Full article

Background/Objectives: Epirubicin, Olaparib, and Ribociclib are widely used anticancer agents whose serum concentrations exhibit significant inter-individual variability, supporting the need for reliable and robust analytical methods suitable for pharmacokinetic evaluation and therapeutic exposure assessment. Variations in metabolism, drug–drug interactions, organ function, and treatment regimens may substantially influence systemic exposure, highlighting the importance of accurate quantification in clinical practice. This study describes the development and validation of a solid-phase extraction–liquid chromatography–mass spectrometry (SPE–LC–MS) method for the simultaneous quantification of these drugs in human serum. Methods: Sample preparation was performed using Oasis PRiME HLB^® cartridges to ensure efficient clean-up, optimal recovery, and reduced matrix effects. Chromatographic separation was achieved using gradient elution with 0.1% formic acid and acetonitrile on a reversed-phase column, followed by single-quadrupole mass spectrometric (QDa) detection in the selected ion recording mode. The total run time was 13 min, enabling high-throughput analysis. Results: The method demonstrated good linearity (r > 0.997) over the tested concentration ranges, along with adequate selectivity, precision, accuracy, recovery, and stability, fulfilling the ICH M10 guideline validation criteria. No significant carry-over or interference from endogenous compounds was observed. Conclusions: Application to patient samples confirmed reliable performance in real clinical matrices and consistent quantification across different concentration levels. The proposed approach provides a potentially more accessible alternative in laboratories already equipped with LC-MS systems compared to LC-MS/MS platforms and can be applied in pharmacokinetic studies, representing a proof-of-concept for exposure assessment in oncology. Full article

Highly sensitive methods for trace-level aflatoxin determination are indispensable for cereal food safety and public health protection. This study developed a ZrO₂-assisted QuEChERS-UHPLC-MS/MS method for the simultaneous determination of AFB₁, AFB₂, AFG₁, and AFG₂ in maize, wheat, rice, and soybean. Systematic optimization identified acetonitrile as the optimal extraction solvent and 10 mg ZrO₂ in combination with PSA, C₁₈, and GCB as the optimal cleanup formulation, providing recoveries of 107.33–111.60%. Chromatographic baseline separation was achieved within 8.0 min using a moderate gradient program. The method exhibited excellent linearity (R² > 0.999) with LODs of 0.15–0.25 µg/kg and LOQs of 0.50–0.75 µg/kg. Negligible matrix effects (0.85–1.02) validated the efficacy of ZrO₂-assisted cleanup in eliminating co-extractive interferences in maize. Satisfactory accuracy (recoveries of 86.66–111.04%) and precision (RSDs < 14%) were obtained across all matrices. The method demonstrated consistent performance across diverse cereal and soybean matrices, fulfilling international regulatory requirements for routine aflatoxin monitoring in agricultural commodities. Full article

Data compatibility remains a major challenge in metabolomics, as commonly used measures of biological material—such as sample weight or cell count—are often poorly reproducible. Here, we systematically evaluated practical normalization strategies for GC × GC-MS-based metabolomic profiling of two widely used model cell lines: human hepatoblastoma (HepG2) and mesenchymal stromal cells (MSCs). We compared orthogonal biomass estimates, including total protein and double-stranded DNA quantified either directly in aliquots of the cell suspension lysate aliquots or in the post-extraction cell precipitate, alongside normalization based on extracted ion current (XIC). We also assessed three widely used extraction mixtures—methanol/chloroform/water (7:2:1); methanol/water (8:2); acetonitrile/isopropanol/water (3:3:2)—for metabolome coverage and normalization robustness. Under realistic biological variability, signal-to-biomass dependencies were moderate. In contrast, under strictly controlled conditions, DNA- and protein-based normalization yielded near-linear relationships with metabolite abundances (R² > 0.90), demonstrating that biological variability is the dominant source of dispersion rather than technical factors. Methanol/chloroform/water system provided the broadest metabolome coverage and strongest correlation with injected biomass. Based on these findings, we recommend normalization to total precipitate protein or DNA using the methanol/chloroform/water extraction protocol, with XIC as a complementary quality control metric. Full article

A method has been developed to delaminate the organic components (paint, foam) from the steel skins of composite polyisocyanurate (PIR) steel insulation panels at ambient temperature and in 20 min using selected solvents combined with ultrasonication. Using this method, polyisocyanurate foam can be selectively delaminated from polymer-based paint (PVC plastisol) and, in turn, the polymer paint can be selectively delaminated from the galvanised steel. Both the foam and paint are removed as intact layers, leaving the galvanised steel intact for the next steps of recycling, enabling the subsequent individualised recycling of each sub-component or layer. Several solvents have been tested, and the data show that H-bonding solvents (e.g., H₂O, alcohols) are less effective at delaminating these polymers. Whilst high polarity, medium H-bonding acetonitrile and DMSO remove PVC paint and some PIR foam, the most effective solvent for both PIR foam and PVC paint removal is medium polarity, medium H-bonding acetone. Full article