Search Results (2,359)

Sulfathiazole (STH) pollution has been increasing, with a strong need for a sensitive and selective analysis method. In this paper, a three-component fluorescent sensing platform with Mn²⁺-doped ZnS quantum dots in a metal–organic framework coated with a surface molecularly imprinted polymer (Mn-ZnS-MOF-MIP) for selective sensing of sulfathiazole is proposed. This synergistic sensor platform combines Mn-ZnS-insensitive emission, MOF-assisted analyte enrichment, and imprinting-based molecular recognition. The sensing platform displays a characteristic turn-off fluorescence with a dominant static quenching mechanism. Under optimal conditions, a broad sensing range with a low detection limit of 13.75 nM can be obtained. Outstanding selectivity among similar sulfonamides, biomolecules, and metal ions were achieved with high reproducibility, stability, and reusability. This sensing platform was shown to analyze sulfathiazole accurately in aqueous samples and blood serum with high recoveries, within the range of 90.00–104.24%, compared to high-performance liquid chromatography methods. Full article

Retinal degeneration is characterized by progressive photoreceptor loss driven by oxidative stress and chronic inflammation, yet effective mutation-independent therapeutic strategies remain limited. Lycium barbarum polysaccharides (LBPs) possess antioxidant and anti-inflammatory activities; however, the structural features responsible for their retinal protective effects remain poorly defined. In this study, crude LBP was fractionated by DEAE-cellulose ion-exchange chromatography, and the most bioactive fraction, LBPF2, was identified using H₂O₂-injured 661W cone photoreceptor-like cells. LBPF2 was subsequently characterized by high-performance anion-exchange chromatography, SEC-MALLS-RI, GC–MS methylation analysis, and one- and two-dimensional NMR spectroscopy, and its protective effects were evaluated in H₂O₂-treated 661W cells and rd10 mice. LBPF2 was identified as a homogeneous glucose-rich polysaccharide with an average molecular weight of approximately 41 kDa and a backbone mainly composed of →4)-α-D-Glcp-(1→ and →4,6)-α-D-Glcp-(1→ residues. LBPF2 reduced oxidative stress, inflammation, and apoptosis in H₂O₂-treated 661W cells, preserved retinal morphology, improved electroretinographic responses and partial retention of rhodopsin immunoreactivity relative to untreated rd10 mice, and restored redox homeostasis in rd10 mice. Pharmacological inhibition of Nrf2 using ML385 attenuated these protective effects, supporting the involvement of Nrf2/HO-1 signaling. Collectively, these findings identify LBPF2 as a structurally characterized neuroprotective polysaccharide that mitigates retinal degeneration through coordinated regulation of oxidative stress and inflammation and highlight its therapeutic potential for retinal degenerative diseases. Full article

The flavor characteristics of three commercially important, cultivated mussel species (Mytilus coruscus, Mytilus galloprovincialis, and Perna viridis) were investigated through analyses of free amino acids, organic acids, 5′-nucleotides, fatty acids, and volatile organic compounds (VOCs). Distinct differences among species–sex groups were observed in both volatile and non-volatile flavor compounds. M. coruscus and M. galloprovincialis showed greater umami potential than P. viridis. Female M. galloprovincialis exhibited the highest equivalent umami concentration (EUC) (2.56 ± 0.21 g MSG/100 g), whereas male M. galloprovincialis and male M. coruscus contained the highest levels of sweet-tasting amino acids (605.42 ± 28.72 mg/100 g) and umami-tasting amino acids (209.29 ± 13.31 mg/100 g), respectively. Gas chromatography–ion mobility spectrometry (GC-IMS) analysis identified 67 volatile compounds, and 12 key discriminative volatiles were selected, including three aldehydes, four ketones, three alcohols, 2-ethylfuran, and acetic acid. Males generally showed higher omega-3 polyunsaturated fatty acids (ω-3 PUFAs)and omega-6 polyunsaturated fatty acids (ω-6 PUFAs) proportions than females, with the highest ω-3 PUFAs proportion in male M. coruscus (45.12 ± 0.22%) and the highest ω-6 PUFAs proportion in male P. viridis (8.13 ± 0.30%). Correlation analysis suggested that ω-6 PUFAs were more closely associated with aldehydes, whereas ω-3 PUFAs were more closely associated with alcohols and ketones. These associations provide preliminary evidence for understanding flavor differences among cultivated mussel groups. Full article

Inonotus obliquus (I. obliquus) is a medicinal fungus rich in polysaccharides, polyphenols, and triterpenoids. However, studies on purified polysaccharide from the black outer layer of the I. obliquus sterile conk remain limited. In this study, crude polysaccharides were extracted by hot-water extraction, optimized using response surface methodology, and further purified by DEAE-52 ion-exchange chromatography and Sephacryl S-400 HR gel filtration chromatography. The structural characteristics and in vitro biological activities of the purified polysaccharide (IOP) were investigated. Under the optimized conditions, the crude polysaccharide extract yield reached 24.64 ± 0.48%. IOP contained 88.97 ± 1.33% total sugars and 10.91 ± 0.37% uronic acids, with a weight-average molecular weight of 78.0 kDa. Monosaccharide analysis revealed that IOP consisted of glucose, galactose, galacturonic acid, and glucuronic acid, and FT-IR analysis revealed the characteristic functional groups of polysaccharides. IOP exhibited concentration-dependent antioxidant activities, inhibited the cell viability of A549, SW1990, 4T1, and B16F10 cells with low cytotoxicity toward L929 fibroblasts, and stimulated the production of NO, TNF-α, IL-6, and IL-1β in RAW264.7 macrophages. These findings provide preliminary evidence that the purified IOP fraction obtained from the black outer layer of the I. obliquus sterile conk exhibits in vitro antioxidant, inhibitory effects on tumor cell viability, and immunomodulatory activities under the tested experimental conditions. Full article

Rapid urbanization and inadequate sanitation infrastructure threaten water security in many sub-Saharan African cities. This study aimed to provide an integrated assessment of groundwater, surface water, and wastewater quality in Bangui by characterizing physicochemical parameters, trace metals, and microbiological indicators, and by identifying potential contamination sources and pathways among these water compartments. A total of 28 water samples were collected from groundwater, surface water, and wastewater sites. Physicochemical parameters, major ions, trace metals, and microbiological indicators were analyzed using standardized methods, including ion chromatography, ICP-OES, ICP-MS, and membrane filtration. Results revealed a clear contamination gradient. Wastewater showed the highest electrical conductivity, turbidity, chloride concentrations, and microbial loads, reaching 2.41 × 10⁶ CFU/100 mL for total coliforms and 1.93 × 10⁶ CFU/100 mL for fecal coliforms. Groundwater exhibited high nitrite levels and low dissolved oxygen, indicating vulnerability to sewage infiltration. Surface waters were characterized by high turbidity and widespread fecal contamination despite relatively good oxygenation. In contrast, trace metal concentrations generally remained below World Health Organization guideline values. Geochemical analyses identified distinct elemental signatures for each water type. Microbiological contamination emerged as the dominant water quality concern. High fecal coliform/fecal streptococci ratios (13.08-22.16) indicated predominantly human-derived pollution linked to untreated wastewater and inadequate sanitation systems. The association between elevated nitrite concentrations and fecal indicators suggests active contamination pathways connecting wastewater, surface water, and shallow aquifers. These findings highlight the urgent need for improved wastewater management, groundwater protection, and long-term monitoring to ensure sustainable urban water security in Bangui. Full article

Solar-assisted thermochemical cycles can convert intermittent solar energy into storable chemical fuels. Within the European SULPHURREAL project, elemental sulfur is investigated as a long-term energy-storage medium in a cycle based on H₂SO₄, S, and SO₂. This work investigates an indirect magnesium-mediated route for the disproportionation of SO₂. The proposed cycle consists of three steps: aqueous reaction of SO₂ with MgO to form sparingly soluble MgSO₃; thermal decomposition of MgSO₃ through competing pathways producing elemental sulfur, MgSO₄, MgO, and SO₂; and high-temperature decomposition of MgSO₄ to regenerate MgO and produce sulfur oxides and oxygen. All three steps were experimentally investigated using laboratory-scale reactors, thermogravimetric analysis, X-ray diffraction, ion chromatography, and calorimetric measurements. The sulfur yield was approximately 25% of the theoretical maximum, corresponding to 8.3% relative to the initial SO₂ amount. Complete MgSO₄ conversion was achieved after 90 min at 1100 °C, at which temperature the SO₂-forming pathway accounted for approximately 87% of the gaseous sulfur products. The experimental results were used to establish a preliminary mass and energy balance for the closed-loop process. The calculated gross heat requirement was 5349 kJ mol⁻¹ of sulfur, corresponding to an energy efficiency of 5.5% when heat recovery was not considered. These results demonstrate the technical feasibility of the proposed magnesium-mediated route and provide a quantitative basis for its further development, identifying sulfur selectivity, high-temperature sulfate decomposition, quantitative product recovery, and heat integration as the main priorities for process optimisation. Full article

Xylan, the principal component of hemicellulose, requires the concerted action of endo- and exo-acting xylanolytic enzymes for its complete depolymerization into fermentable sugars. This study reports the biochemical and thermodynamic characterization of a glycoside hydrolase family 10 endo-β-1,4-xylanase from the thermophilic bacterium Geobacillus stearothermophilus CECT43 (GsXynA), cloned and heterologously expressed in Escherichia coli BL21(DE3) and purified to homogeneity by immobilized metal-ion affinity chromatography. The 338-residue enzyme behaved as a monomer and showed maximal activity on xylan substrates at pH 6.5 and 75 °C, retaining over 90% residual activity between pH 5 and 9 and remaining stable up to 70 °C, after 60 min of incubation. Kinetic and thermodynamic analyses of thermal inactivation monitored by enzymatic activity measurements revealed an enthalpy-driven denaturation process, while circular dichroism indicated that this irreversible unfolding is kinetically, not thermodynamically, controlled. GsXynA hydrolyzed beechwood xylan mainly to xylobiose and xylotetraose, consistent with mixed endo and exo activity, and was uncompetitively inhibited by 4-hydroxybenzoic acid. Combined action with the β-xylosidase GsXynB2 markedly increased D-xylose release, reaching a 53.23% hydrolysis yield and a degree of synergy of 3.79 after 24 h. These results demonstrate that GsXynA is a thermostable, versatile xylanase with promising potential for lignocellulosic biomass bioconversion. Full article

To investigate the differences in pulp metabolites among four varieties of Pouteria caimito fruit (JZL1, JZL3, JZL5, and JZL6), ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was employed for the separation and identification of metabolites. A total of 1285 metabolites were identified, including 648 in positive ion mode and 637 in negative ion mode. At the class level, carboxylic acids and derivatives (14.32%) and organooxygen compounds (11.83%) accounted for the highest proportions; at the subclass level, amino acids, peptides, and analogues (12.53%) as well as carbohydrates and carbohydrate conjugates (9.49%) were the main categories. PLS-DA analysis revealed significant differences in metabolite profiles among the four varieties, with numerous up-regulated and down-regulated metabolites in each comparison group, and some metabolites showed fold changes > 10 or <0.1. KEGG pathway enrichment analysis further indicated that differential metabolites were primarily enriched in pathways such as ABC transporters, citrate cycle (TCA cycle), starch and sucrose metabolism, and linoleic acid metabolism. This study provides an important metabolomic basis for variety identification, nutritional quality evaluation, and functional component development of Pouteria caimito fruit. Full article

Roasting time strongly influences almond oil yield, flavor and oxidative stability. This study investigated almond oils obtained by pressing almond kernels roasted at 130 °C for 0, 5, 10 and 20 min, corresponding to cold-aroma, light-aroma, strong-aroma and sauce-aroma groups, respectively, by combining physicochemical analysis, fatty acid quantification, gas chromatography–ion mobility spectrometry (GC-IMS), machine learning and lipidomics. Increasing roasting time enhanced oil yield from 45.81% to 50.34%, with no further significant increase after 10 min. Stronger roasting moderately reduced the free radical level. In contrast, acid value, peroxide value and thiobarbituric acid reactive substances (TBARS) increased from 0.28 to 0.38 mg KOH/g oil, 1.20 to 1.46 meq O₂/kg oil and 0.38 to 0.46 mg malondialdehyde/kg oil, respectively, indicating limited oxidative deterioration. Fatty acid analysis showed that oleic acid remained relatively stable at 644.37–647.03 mg/g oil, whereas linoleic acid decreased significantly from 150.42 to 140.19 mg/g oil. GC-IMS detected 59 volatile signals and clearly separated the four processing groups, indicating substantial roasting-induced changes in volatile fingerprints. A positive–unlabeled (PU) learning model used 27 literature-supported aroma-active compounds as the positive class and 32 compounds without confirmed aroma-activity evidence as the unlabeled class. The model showed good cross-validated discrimination, with a mean area under the receiver operating characteristic curve (ROC-AUC) of 0.866 and a mean area under the precision–recall curve (PR-AUC) of 0.756, and prioritized eight unlabeled compounds, mainly alcohols and methional, as candidate aroma-active compounds requiring further sensory validation. Lipidomic analysis showed that accelerated oxidation caused broad lipid remodeling, with 327 differential lipids between cold-aroma oxidized and unoxidized oils, mainly involving glycerophospholipids, glycerol lipids, sphingolipids and fatty acyls. Overall, increasing roasting time improved oil recovery and promoted aroma differentiation while causing only limited initial oxidative deterioration, providing a theoretical basis for optimizing roasting conditions in industrial processing. Full article

Bamboo leaves contain structurally diverse flavonoid glycosides; whereas, compound-level information for Bambusa textilis remains limited. In this study, a flavonoid-enriched 40% ethanol fraction prepared from B. textilis leaves by petroleum-ether partitioning and AB-8 resin adsorption was analyzed by ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-Q-TOF-MS/MS) in negative-ion mode. Retention times and MS/MS spectra were compared with seven in-house reference standards, while the remaining constituents were annotated from accurate-mass measurements, diagnostic product ions, fragmentation behavior, and data from the literature. According to Metabolomics Standards Initiative criteria, seven compounds were assigned at Level 1 and twenty-four were reported as Level 3 annotations because their exact positional structures were not confirmed by additional standards or NMR. Thirty-one flavonoid-related constituents were annotated in the analyzed fraction, encompassing six glycoside classes; most annotations, by count, were apigenin- or luteolin-derived. These annotations add compound-level information for the analyzed B. textilis fraction and allow qualitative comparison with other bamboo flavonoid profiles. Because the sample was selectively enriched, the results do not describe the complete leaf metabolome or compound concentrations. Additional standards or NMR analysis are needed to confirm the glycosylation positions of tentatively annotated compounds. Full article

Brassica crops, encompassing globally important vegetables and oilseeds, face severe threats from diverse biotic and abiotic stresses. Plant secondary metabolites constitute the chemical foundation of defence, and metabolomics has emerged as an effective systems biology tool for comprehensively dissecting stress-induced metabolic changes. Recent progress in applying metabolomics to elucidate defence mechanisms in Brassica crops is systematically synthesised here. Major stresses confronting Brassica crop production and the metabolic basis of plant defence are first outlined. Current analytical platforms, including liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry, ion mobility spectrometry, and mass spectrometry imaging, are critically evaluated alongside data processing workflows and multi-omics integration strategies. Key defence-related metabolite classes identified in Brassica crops, notably glucosinolates (GSLs) and their hydrolysis products, phenolic compounds, and lipid-derived signalling molecules, are surveyed with emphasis on their respective functions in biotic and abiotic stress responses. Metabolomics has been instrumental in revealing distinct metabolic reprogramming patterns triggered by diverse stresses, including pathogen infection, insect herbivory, drought, salinity, temperature extremes, and heavy metal stress. Metabolomics-informed crop improvement strategies, including marker-assisted breeding, genetic and metabolic engineering, and precision agronomic practices, are discussed together with current technical bottlenecks and future directions involving artificial intelligence, metabolic modelling, and spatial metabolomics. The compiled knowledge provides a comprehensive reference for leveraging metabolomics to enhance stress resilience and sustainable production of Brassica crops. Full article

Cariprazine (CAR) and lurasidone (LUR) are antipsychotic drugs used to treat schizophrenia. These drugs are relatively new in clinical practice, and there is a need to optimise and develop analytical methods for their determination in various biological matrices for biomedical analysis. To date, the detection of these drugs has been performed in serum and urine, but there are no methods for determining these drugs in saliva. In the first part of this study, various chromatographic systems were compared using high-performance liquid chromatography with diode array detection (HPLC-DAD) or coupled with quadrupole–linear ion trap tandem mass spectrometry (HPLC-QTRAP-MS/MS), taking into account the retention of tested compounds, system efficiency and peak symmetry. Next, a simple, rapid, and sensitive HPLC-QTRAP-MS/MS method has been developed for the determination of CAR and LUR in human serum, urine, and, for the first time, in saliva samples. Solid-phase extraction (SPE) was used for sample pre-treatment. Quantifications were carried out using a Polar RP column with a mobile phase consisting of acetonitrile and a formate buffer at pH 4.0 in gradient mode. The method was successfully applied for the determination of CAR and LUR in biological samples obtained from psychiatric patients. The findings suggest that saliva may be a non-invasive alternative for the quantification of free levels of investigated drugs, although further studies are required to clarify its relationship with plasma concentrations. 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

Huangshui (HS), fermented grains (FG), and pit mud (PM) are closely connected during the fermentation of Nongxiangxing baijiu (NXB); however, the contribution of HS to the differences in flavor profiles across PM, FG, and distilled baijiu has not been fully elucidated. Herein, instrumental techniques of electronic nose (E-nose), headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS) were used to compare the volatile profiles of HS, FG, PM, and two quality grades of NXB. E-nose analysis revealed that PM exhibited stronger signals related to sulfur-containing, organic, and terpene-associated compounds. Gas chromatography indicated that special-grade baijiu had a more favorable ethyl caproate/ethyl lactate ratio than superior-grade baijiu. Furthermore, HS-GC-IMS revealed different volatile profiles of the samples. Up to 183 volatile organic compounds (VOCs) were identified via HS-SPME-GC-MS, with esters and acids being the dominant classes. Multivariate analysis showed close relationships among HS, FG, and PM, and 35 VOCs were identified as important discriminatory compounds. These results suggest the differences and similarities in VOCs among the HS, FG, PM, and NXB samples, indicating that HS is chemically associated with both FG and PM. This study provides useful insights into HS utilization and quality regulation of NXB through the effective management of HS. 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