Search Results (3,415)

Ultrasonically assisted catalysis—also called sonocatalysis—is one of the advanced oxidation processes used for wastewater treatment. It has been shown that using nanoparticles of piezoelectric materials as nanocatalysts in sonocatalysis greatly enhances the catalytic reaction rates, a phenomenon that has been dubbed piezocatalysis. Since both sonocatalysis and piezocatalysis are excited by ultrasonic waves and occur simultaneously, it is challenging to discriminate between these two processes and to quantify the contribution of the material’s piezoelectric properties to the overall catalytic activity. It has been previously reported that the piezoelectric properties of the catalyst nanoparticles can improve their catalytic activities by up to one order of magnitude. In this study, we compare the catalytic activity of nanoparticles of both ferroelectric and paraelectric BaTiO₃, hence piezoelectric and non-piezoelectric BaTiO₃ nanoparticles. BaTiO₃ nanoparticles of two different sizes were synthesized using a microwave-assisted hydrothermal method. After a full characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and temperature-dependent Raman spectroscopy, the catalytic activities of the BaTiO₃ nanoparticles were determined by monitoring the time dependence of the optical absorption of a solution containing the model pollutant methyl orange, to which the dispersed piezoelectric BaTiO₃ particles were added as catalysts. The 50 nm nanoparticles were found to have a tetragonal crystal structure and symmetry and to be piezoelectric, while the 10 nm nanoparticles had a cubic crystal structure and symmetry and exhibited no piezoelectricity. This study reveals that non-piezoelectric BaTiO₃ nanoparticles exhibit a moderate catalytic activity for the degradation of methyl orange, similar to that of non-piezoelectric TiO₂ nanoparticles. Furthermore, it also shows that, at room temperature, 90% of the overall catalytic activity of piezoelectric BaTiO₃ nanoparticles is due to piezocatalysis, while the remaining 10% is related to sonocatalysis. Using liquid chromatography coupled to mass spectrometry (LC-MS), possible chemical decomposition pathways of the methyl orange dye have also been suggested. Full article

Honey is a natural food product highly valued for its nutritional and biological properties. Its quality and safety are increasingly affected by environmental contamination and apicultural practices. Among the most relevant contaminants, pesticide residues, veterinary antibiotics, and heavy metals represent major concerns due to their potential impact on human health. This review provides a comprehensive overview of the occurrence, sources, and distribution of these contaminants in honey, with particular emphasis on their relationship with agricultural activities, environmental pollution, and beekeeping treatments. Advanced analytical techniques, including liquid chromatography–tandem mass spectrometry (LC-MS/MS), gas chromatography–mass spectrometry (GC-MS), and inductively coupled plasma–mass spectrometry (ICP-MS), are highlighted for their ability to enable sensitive multi-residue and trace-level detection. The application of chemometric tools for data analysis and sample classification is also addressed, supporting the identification of contamination patterns and origin-related differences. In addition, recent developments in rapid screening methods and environmentally sustainable analytical approaches are discussed. Overall, this review emphasizes the importance of continuous monitoring and the integration of advanced analytical strategies to ensure honey safety, support regulatory compliance, and protect consumers. Full article

Plant pathogenic fungi pose a major threat to global crop production and food security, necessitating the development of sustainable control agents. This study investigated the antifungal potential of Pseudophaeolus soloniensis, a wood-decaying fungus. A wild strain was isolated from Hebei, China, and identified via morphology and ITS sequencing. A bioactive crude extract (P1) was obtained through optimized solid-state fermentation on A3M medium. Its antimicrobial spectrum was evaluated against major phytopathogenic fungi (e.g., Fusarium graminearum, Aspergillus flavus) and model bacteria (Staphylococcus aureus, Escherichia coli) using mycelial growth inhibition, Minimum Inhibitory Concentration (MIC), and agar diffusion assays. P1 exhibited strong, selective activity, showing significantly greater inhibition against S. aureus than E. coli and pronounced effects against F. graminearum (43.79% inhibition at 20 µg/mL) and A. flavus (73.5% at 0.2 mg/mL). A hormetic-like response was observed for F. oxysporum. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis revealed a diverse secondary metabolome, including flavonoids, alkaloids, quinones, and saponins. These results establish P. soloniensis as a promising source of bioactive metabolites for developing eco-friendly fungicides. Full article

Background: Metabolic syndrome (MetS) is a heterogeneous cardiometabolic group of conditions in which early disturbances of glucose homeostasis are not always adequately captured by routine clinical tests. Methods: In this pilot study, liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based blood serum peptidomics was applied to identify circulating peptide signatures associated with MetS and progressive glycemic impairment. Serum samples from healthy donors and patients with MetS, including subgroups with normoglycemia, prediabetes, and diabetes mellitus, were subjected to peptide enrichment by ultrafiltration and solid-phase extraction prior to LC-MS/MS analysis. Results: Overall, 6754 unique peptides derived from 1820 precursor proteins were identified, and 32 peptides were significantly overrepresented in patients with MetS relative to healthy donors. Eight precursor proteins and five identified peptides showed significant positive correlations with glycemic stage, likely indicating progressive remodeling of the circulating serum peptidome during disease progression. A separate analysis of patients with prediabetes revealed additional candidate markers associated with early metabolic alterations. Moreover, multivariate logistic regression identified a four-peptide panel with good discriminatory performance for differentiating healthy donors from patients with MetS, yielding a leave-one-out cross-validated area under the curve of 0.91. Conclusions: Collectively, these findings indicate that serum peptidome profiling can reveal biologically and clinically relevant possible candidate biomarkers associated with MetS and early dysglycemia. Full article

The resource utilization of eutrophic cyanobacterial biomass provides a sustainable route for developing biochar-based catalytic materials for dye wastewater treatment. Herein, eutrophic cyanobacteria from Dianchi Lake, Kunming, were used as raw materials to prepare functional catalytic materials via pyrolysis-modification. A trimetallic photocatalyst, CuFeZnXBC₄₀₀ (XBC = cyanobacterial biochar), was fabricated for methylene blue (MB) degradation without hydrogen peroxide or other external oxidants. The samples were characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), liquid chromatography–mass spectrometry (LC–MS), and three-dimensional fluorescence spectroscopy. At an initial MB concentration of 100 mg/L and pH 11, under UV irradiation, CuFeZnXBC₄₀₀ achieved nearly 99% MB removal within 60 min and retained over 90% activity after eight cycles. Transient photocurrent measurements and quenching experiments indicated that photogenerated holes (h⁺) were the dominant oxidative species, while superoxide radicals (·O₂⁻) contributed to the reaction and hydroxyl radicals (·OH) played a limited role. LC–MS analysis supported the chemical transformation of MB, and three possible degradation pathways were proposed. The development of CuFeZnXBC400 provides a new biochar-based material and a potential strategy for cyanobacterial biomass utilization and organic dye wastewater treatment. Full article

Background: This study aimed to compare a chemiluminescence immunoassay (CLIA; Siemens Atellica IM 1600) with an automated liquid chromatography–tandem mass spectrometry (LC–MS/MS) analyser (Thermo Scientific Cascadion SM) for serum 25-hydroxyvitamin D [25(OH)D] measurement in unselected outpatients, and its impact on clinical classification. Methods: 25(OH)D was measured on 1064 paired serum samples (828 women, 236 men; age 3–111 years); both platforms participated in the Vitamin D Standardisation Program (VDSP). Agreement was assessed by the Wilcoxon signed-rank test, Passing–Bablok regression, Bland–Altman analysis on log-transformed values, Breusch–Pagan testing for heteroscedasticity, consistency-based intraclass correlation coefficient (ICC), Lin’s concordance correlation coefficient, and Cohen’s kappa with McNemar’s test on six- and two-category clinical classifications. Results: Methods differed significantly ($p<2.2\times {10}^{-16}$). Passing–Bablok regression showed proportional bias (slope 1.33; 95% confidence interval [CI], 1.28–1.38; LC–MS/MS higher). Consistency ICC was 0.928 (95% CI, 0.919–0.936). Log-Bland–Altman bias was 35.5% (limits of agreement, $-18.3$% to $+124.5$%; heteroscedasticity, $p=5.18\times {10}^{-11}$). Cohen’s kappa was 0.32 unweighted and 0.72 weighted on six clinical categories, and 0.56 on a two-class scheme (McNemar $p<2.2\times {10}^{-16}$). In discordant pairs, CLIA classified deficiency 118-fold more often than LC–MS/MS. Conclusions: In our study, despite preserved rank ordering, a non-linear concentration-dependent bias and different limits of agreement caused systematic differences in the classification of vitamin D deficiency. Adoption of automated LC–MS/MS can substantially reclassify outpatients toward sufficiency, with implications for supplementation and laboratory harmonisation. Full article

Background/Objectives: Mesoporous silica nanoparticles (MSNs) are widely investigated as nanocarriers for drug delivery, gene transfer, and bioimaging. However, the mechanisms underlying their size-dependent cytotoxicity at the metabolic level remain incompletely understood. This study aimed to determine whether different-sized MSNs induce distinct patterns of subcellular injury and metabolic reprogramming in lung epithelial cells. Methods: A549 cells were exposed to 80 nm and 600 nm MSNs at 50 and 200 μg/mL for 24 h. Ultrastructural changes were examined by transmission electron microscopy (TEM). Intracellular reactive oxygen species (ROS) and Ca²⁺ were measured by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) and Fluo-4 AM fluorescence, respectively. Inflammatory gene expression (IL1B, IL6, TNFA, HIF1A) was quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Untargeted metabolomics were performed using combined gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) platforms, followed by principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and MetaboAnalyst-based pathway enrichment. Results: TEM revealed distinct size-dependent subcellular distributions: 80 nm MSNs were predominantly associated with mitochondrial abnormalities, including cristae disruption, swelling, and mitophagy-like features, whereas 600 nm MSNs accumulated in endocytic vesicles with membrane disruption. Metabolomic profiling showed that 80 nm MSNs were associated with TCA cycle blockade—characterized by the accumulation of early intermediates (citrate, oxaloacetate) and the depletion of distal intermediates (fumarate, malate)—with compensatory glycolytic activation (increased glyceraldehyde-3-phosphate and pyruvate) and reduced deoxynucleotide pools (dCDP, dUMP). By contrast, 600 nm MSNs triggered broad nucleotide triphosphate accumulation (ATP, CTP, dGTP, dCTP), amino acid depletion, and robust inflammatory activation, including a ~136-fold increase in IL1B expression and HIF1A transcriptional upregulation. PCA and PLS-DA confirmed distinct size-dependent metabolic phenotypes. Conclusions: MSN size strongly influences subcellular targeting—80 nm particles were predominantly associated with mitochondrial injury while 600 nm particles disrupted endocytic vesicles—driving qualitatively distinct patterns of metabolic reprogramming and inflammatory signaling. These findings establish a correlative mechanistic framework linking particle size to organelle-specific injury and provide candidate metabolic markers for nanotoxicological evaluation. Full article

Background/Objectives: Opiates comprise naturally occurring opium alkaloids and their semisynthetic derivatives. Routine urine drug screening relies on enzyme immunoassays (EIAs) to rapidly detect opiate exposure; however, EIAs provide limited insight into opiate-associated metabolic patterns. Methods: We retrospectively analyzed liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-qToF-MS) datasets from comprehensive urine drug screening of 363 patients at the University of Pittsburgh Medical Center Clinical Toxicology Laboratory. Multiple statistical analyses were applied to identify the features associated with opiate (OPIA)-EIA-positive, oxycodone (OXY)-EIA-positive, and 6-monoacetylmorphine (6MAM)-EIA-positive specimens (42, 34, and seven specimens, respectively) designated as EIA-associated discovery feature sets. The feature sets selected by ≥2 statistical analyses were defined as EIA-associated consensus feature set and further evaluated using MS-FINDER for feature annotation. Results: Among 14,883 features, 138, 121, and 104 features were assigned to the OPIA-, OXY-, and 6MAM-EIA discovery feature sets, respectively. Consensus feature sets included oxycodone/opiate metabolites, acetaminophen metabolites, and norfentanyl for OPIA-EIA; oxycodone metabolites, α-phenylalanylaspartic acid, and 4-pyridoxic acid for OXY-EIA; and norfentanyl, 6-monoacetylmorphine, and 3-hydroxycotinine artifact for 6MAM-EIA. Conclusions: These metabolomic patterns indicate a dominant exposure gradient model, in which OXY-EIA-positive specimens primarily reflect prescribed oxycodone exposure, 6-MAM-EIA-positive specimens reflect illicit heroin/fentanyl exposure with polysubstance/recreational use signature, and OPIA-EIA-positive specimens occupy an intermediate, mixed profile shaped by immunoassay cross-reactivity and real-world co-exposures. Associations involving α-phenylalanylaspartic acid and 4-pyridoxic acid are hypothesis-generating and require further validation. These findings illustrate the value of archived clinical toxicology datasets for metabolomic discovery and as a foundation for sentinel laboratory-based surveillance of evolving drug and chemical exposures. Full article

Argemone ochroleuca and Argemone mexicana are widespread weed species known for being rich in various secondary metabolites. However, a comprehensive understanding of their chemical diversity remains limited. Insufficient information exists on metabolite variation between plant parts and the influence of solvent polarity on metabolite recovery. Therefore, this study aimed to characterize the metabolomic profiles of the shoots and root extracts of both species using solvents of varying polarity to evaluate plant part-specific metabolite distribution and solvent effects on metabolome coverage. Untargeted ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS)-based metabolomics and molecular networking were employed for metabolite analysis. Principal component analysis (PCA) did not reveal clear clustering of A. ochroleuca and A. mexicana, suggesting similarities in their metabolomic profiles. A total of 15 and 13 metabolite classes, yielding 59 and 54 metabolites, were identified in A. ochroleuca and A. mexicana, respectively, including flavonoids, terpenoids, phenolic compounds, fatty acids, and monoterpenoids. Argemone ochroleuca exhibited higher metabolite abundance, particularly in methanol and acetone extracts, and with shoots showing higher abundance than roots, with flavonoids being the dominant class. The findings show that LC-MS metabolomics, molecular networking, and careful solvent selection are effective for identifying key metabolites with potential applications in crop protection. Full article

Background: Koalas are a vulnerable marsupial species with unique reproductive traits. Efforts to develop assisted breeding technologies have been hindered by a limited understanding of maternal recognition of pregnancy and physiological changes induced by the foeto-placental unit. Differences in the reproductive physiology of pregnant and non-pregnant koalas were examined to investigate the possibility of maternal recognition and identify potential pregnancy and/or embryonic loss biomarkers. Methods: Koalas were separated into three groups: pregnant (n = 4 cycles from three females), mated but non-parturient (n = 4 cycles from three females), and gonadotropin-releasing hormone (GnRH) agonist-treated females (n = 7). Plasma was collected on day of mating/GnRH injection (D0) and on multiple subsequent days. Progesterone concentrations were measured by enzyme immunoassay, and plasma proteomes were analysed using filter-aided sample preparation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), employing sequential window acquisition of all theoretical fragment ion spectra. Results: Ovulation induction mechanisms influenced peri-ovulatory progesterone secretion (pregnant 40.7 ± 3.3 ng/mL vs. GnRH-treated 15.7 ± 1.8 ng/mL), with no significant differences in progesterone that occurred later in the luteal phase. LC-MS/MS identified 158 proteins, representing the first koala plasma proteome. Leucine-rich alpha-2-glycoprotein (LRG1) was significantly elevated at D2 in pregnant females compared to GnRH-treated females, and pregnant D9 and D19. In pregnant females, fibronectin (FN1) was significantly more abundant at D19 compared to D9 but not significantly different between treatments. Conclusions: These preliminary findings provide foundational data for further investigation into maternal recognition and pregnancy/embryonic loss in koalas. Full article

Antimicrobial peptides (AMPs) are promising alternatives to antibiotics for combating multidrug-resistant bacteria, yet their practical application is hindered by the low content of natural AMPs and the high cost of chemical synthesis. In this study, we developed a high-efficiency heterologous expression system for the proline-rich cationic antimicrobial peptide Api137 in Saccharomyces cerevisiae CENPK2 by engineering the Ty retrotransposon system composed of multi-locus integration. Recombinant plasmids carrying Api137 encoding elements were constructed and integrated into the CENPK2 genome, generating the engineered strain CENPK2 + Ty1-2/2/3/4. The target fusion peptide (5.2 kDa) was successfully expressed and identified by Tris-tricine-SDS-PAGE and liquid chromatography–tandem mass spectrometry (LC-MS/MS). The quantification of Api137 from fermentation broth was applied by high-performance liquid chromatography (HPLC) which showed that the yield of tandem peptide in the fermentation supernatant reached 20.5 mg/L and the intracellular retention rate was 33.0%. Comparative analysis of MIC and MBC values revealed that the biologically synthesized Api137 exhibited slightly superior antibacterial activity relative to the chemically synthesized Api137. In vitro functional assays demonstrated that the fermentation supernatant of the engineered strain exhibited broad-spectrum antibacterial activity against five pathogenic bacteria, with a maximum antibacterial rate of 92.9% against Aeromonas veronii. Hemolysis assays and cytotoxicity tests confirmed that the fermentation supernatant exhibited neither hemolytic activity nor cytotoxicity. Moreover, the expression of Api137 did not impose a metabolic burden on the host. This study establishes a Ty transposon-mediated strategy for the high-level expression of Api137 in S. cerevisiae, which significantly demonstrates the antibacterial activity of Api137 while ensuring excellent biosafety. Full article

Thanatin is a small cationic antimicrobial peptide with broad-spectrum antibacterial activity, considered a promising candidate to combat the global antibiotic resistance crisis. Microbial biosynthesis represents an attractive strategy for sustainable production of antimicrobial peptides. In this study, we constructed a heterologous expression system for thanatin in Saccharomyces cerevisiae CENPK2 using both PiggyBac (PB) and Ty2 retrotransposon systems, demonstrating the utility of yeast as a host for peptide production and transposon-based genetic engineering. By designing transposon-based expression plasmids incorporating the CL1 selection tag, we achieved efficient expression of thanatin. The expression of thanatin-derived peptides was confirmed by Tris-tricine-SDS-PAGE and liquid chromatography-mass spectrometry (LC-MS). In vitro antibacterial assays demonstrated that the fermentation supernatant of engineered yeast significantly inhibited the growth of Escherichia coli O157: H7, Salmonella typhimurium, Aeromonas veronii (JL-2), and Acinetobacter baumannii. Notably, strains harboring both PB and Ty2 systems exhibited stronger antibacterial activity than those with a single system. Scanning electron microscopy further revealed that thanatin caused damage to bacterial cell membranes and led to cell lysis. Hemolysis tests proved that the physiological saline-replaced fermentation supernatant possessed low hemolytic activity. This study successfully established a transposon-based platform for the heterologous expression of thanatin. Full article

Background/Objectives: Ambient fine particulate matter (PM_2.5) poses significant health risks to older adult populations, yet the specific contributions of its chemical constituents, particularly non-phthalate and non-organophosphate ester compounds, remain poorly understood. This study aimed to elucidate the mechanistic links between PM_2.5-bound ester exposures and metabolic pathway alterations in elderly individuals. Methods: A total of 258 elderly residents aged 60 years or older from Fuzhou, China, were recruited. Personal PM_2.5 exposure was monitored over 72 h using UPAS V2 samplers, with chemical components analyzed via gas chromatography–mass spectrometry (GC–MS). Plasma metabolomic profiling was conducted using liquid chromatography–mass spectrometry (LC–MS), and metabolic pathway enrichment was performed using MetaboAnalyst 5.0. Linear regression models adjusted for covariates (age, sex, BMI, lifestyle factors) assessed associations between ester exposures and metabolite abundance. Results: The mean PM_2.5 concentration was 38.06 μg/m³, with ester compounds dominating the chemical composition. Twenty high-concentration non-target esters were prioritized for analysis. PM_2.5 ester exposure was associated with alterations in key metabolic pathways, including steroid biosynthesis, glycolysis/gluconeogenesis, glycerophospholipid metabolism, and purine/pyrimidine metabolism. When interpreted alongside prior epidemiological evidence, these alterations represent putative links to increased risks of insulin resistance, cardiovascular dysfunction, and metabolic syndrome—relationships that require confirmation in prospective cohort studies and controlled toxicological experiments. Conclusions: Putatively annotated PM_2.5-bound ester compounds, particularly non-regulated subclasses, are associated with systemic metabolic alterations in older adults, coincident with perturbations in steroid and lipid metabolism. While these findings are exploratory and hypothesis-generating, they highlight the need to incorporate specific ester profiles into PM_2.5 risk assessments and develop targeted interventions for vulnerable aging populations. Full article

Liquid- and solid-state fermentation are both used to produce Eurotium cristatum-fermented Fu tea, but their final soluble products have rarely been compared directly. We compared a liquid-state fermented tea infusion (LFt-D7) with an aqueous extract of solid-state fermented Fu tea (SFt-D7), using an unfermented sterilized tea extract (SHt-D0) as the reference group. LFt-D7 developed a darker reddish-brown appearance and had higher theaflavin and theabrownin contents, lower thearubigin content, and larger Commission Internationale de l’Éclairage L*a*b* (CIELAB) color differences than SHt-D0 and SFt-D7. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) profiling separated the three endpoint groups; 221, 180, and 203 Level 2 annotations met the variable importance in projection (VIP > 1) and nominal p < 0.05 screening criteria in LFt-D7 versus SHt-D0, SFt-D7 versus SHt-D0, and LFt-D7 versus SFt-D7, respectively. Targeted analyses showed substantially lower free amino acid levels in SFt-D7. LFt-D7 retained a larger soluble free-amino-acid pool, had the highest total quantified flavonoid content with a stronger flavanol contribution, and showed higher relative peak-intensity signals for selected alkaloid- and phenolic acid-related metabolites. Mantel analysis showed covariation between metabolite modules and pigment indices, CIELAB parameters, total free amino acid (FAA) content, and total quantified flavonoid content. Together, these results show that the two complete preparation routes produce different soluble chemical profiles. Full article

Messenger RNA–lipid nanoparticles (mRNA-LNPs) have emerged as a transformative platform for nucleic acid therapeutics, yet their complex four-component lipid architecture comprising ionizable lipids, PEG–lipids, helper phospholipids, and cholesterol presents substantial analytical challenges for quality control and regulatory compliance. This review presents, for the first time, a critical evaluation of liquid chromatography–mass spectrometry (LC-MS) strategies specifically tailored to quantify all four lipid classes and their degradation products within mRNA-LNP formulations. Unlike prior general lipidomics reviews, we provide a comparative assessment of orthogonal LC modalities including reversed-phase ultra-high-performance liquid chromatography, hydrophilic-interaction liquid chromatography, ion-pairing reversed-phase LC, and high-performance liquid chromatography charged aerosol detection with explicit performance metrics (sensitivity, linearity, and run time). We further integrate emerging analytical frontiers—single-particle analysis, degradation product profiling (e.g., oxysterols and reactive electrophiles), and regulatory frameworks (ICH Q2(R1), Analytical Quality by Design)—to offer a practical guide for method selection. This review’s uniqueness lies in its systematic, application-focused comparison of LC-MS workflows addressing lipid-specific vulnerabilities, matrix effects, and stability-indicating parameters, filling a critical gap between analytical chemistry and mRNA-LNP product development. Full article