Search Results (17,191)

Rapid and efficient elemental characterization of lignocellulosic biomass, such as grapevine cane residues, is essential for its effective utilization in energy and material applications; however, conventional analytical methods typically require extensive sample preparation and are therefore not suitable for rapid screening purposes. In this study, laser-induced breakdown spectroscopy (LIBS) based on TEA CO₂ laser ablation is applied as a direct and minimally destructive approach for the analysis of grapevine cane biomass. Emission spectra recorded in the 190–780 nm range enabled qualitative identification of the elements present in the biomass, supporting the applicability of LIBS for multi-element analysis of complex solid matrices. Quantitative determination of Mg, Ca, K, and Na was achieved using an external calibration approach with solid-spiked standards, yielding good linearity (R² = 0.976–0.990), with concentrations in good agreement with reference ICP–OES measurements. Plasma diagnostics indicated a temperature of approximately 10,500 K and an electron number density on the order of 10¹⁶ cm⁻³, supporting the assumption of local thermodynamic equilibrium (LTE) conditions. The results demonstrate that LIBS provides a rapid and practical tool for direct elemental screening of vine shoot biomass, with potential application in the assessment of agricultural residues for carbon-based material production and related valorization pathways. Full article

Background/Objectives: Chromosome research is essential for advancing our understanding of cytogenetics, gene regulation and numerous aspects of organismal health. Staining chromosomes with 4′,6-diamidino-2-phenylindole (DAPI) and applying Fluorescence Lifetime Imaging Microscopy (FLIM) enables the assessment of structural changes in pericentromeric and heterochromatin-rich region of chromosomes 1, with a shorter fluorescence lifetime (FLT) in the pericentromeric regions compared to the arms. Methods: We used FLIM to optimise sample preparation conditions for more robust imaging and furthermore to measure the impact of low-dose X-ray ionising radiation on chromosome structure when labelled with DAPI. Results: We applied this method to different DNA stains bound to chromosomes where only DAPI led to a clear FLT difference between the chromosome arms (p,q) with 2.98 ± 0.12 ns and 2.65 ± 0.07 ns at the pericentromeric region, while similar stains, such as Hoechst 33258 and NucBlue^TM did not highlight these regions as clearly following FLIM analysis. Our data showed that chromosomes of cells irradiated with 0.1 Gy and 1 Gy did not show a significant change in FLTs (2.94 ± 0.09 ns on the arms and 2.60 ± 0.06 ns on the pericentromeric region) of chromosome 1. Whilst irradiation with 0.5 Gy led to a noticeable and significant reduction in FLT with 2.42 ± 0.13 ns on the arms and 2.12 ± 0.06 ns on the pericentromeric region of HeLa chromosomes. The same pattern could also be seen on X-ray-irradiated T-cell chromosomes. Conclusions: These findings indicate that DAPI FLT may be a useful tool to measure chromosomal structural changes and further suggests that chromosomes undergo distinct structural changes at the pericentromeric region following low-dose irradiation. Full article

The determination of soluble elemental contaminants in tattoo inks is challenged by the lack of standardized extraction procedures, limiting the comparability of analytical results and the assessment of exposure-relevant fractions under the European REACH framework. In this study, artificial sweat extraction was applied as a mild and physiologically relevant approach to evaluate elements potentially released from tattoo inks under sweat-simulated skin-contact conditions. Seventy-eight commercial tattoo inks of different colors were extracted with artificial sweat at 37 °C for 1 h and analyzed by inductively coupled plasma mass spectrometry. Optimization of collision/reaction cell conditions, dilution strategy, and internal standard correction effectively reduced matrix-related interferences caused by the high salt and chloride content of artificial sweat, ensuring reliable quantification. Matrix-matched calibration was required due to significant signal suppression for several analytes. Method accuracy and precision, assessed using NIST 1643f and spiked samples, were generally satisfactory. Elemental release showed marked color-dependent trends, particularly for Cu, Zn, Ba, Al, Ga, Si, Sr, and Zr, reflecting differences in pigment composition and formulation. Soluble Ba, Cu, and Zn remained below EU regulatory limits. While total digestion remains essential for complete characterization, the proposed methodology provides a simple and transferable tool for exposure-oriented assessment of potentially bioaccessible elements in tattoo inks. Full article

Rare earth element (REE) detection sensitivity with minimal sample damage is exciting. Laser-induced breakdown spectroscopy (LIBS) with a typical methodology is a useful diagnostic tool, but often shows poor REE sensitivity. This study presents the qualitative, quantitative, and classification analysis of REE-bearing ore samples that contain multiple elements from the lanthanoid (Ln) group (e.g., La, Ce, Nd, Sm, and Gd) using the LIBS technique, and the results are compared with those obtained using a magnetic-field-assisted LIBS (MFA-LIBS) system. The LIBS spectrum was recorded using a Nd:YAG Laser with a 532 nm emission wavelength, a 5 ns pulse duration, and a 10 Hz repetition rate. Optical regions exhibiting the strongest emission lines of REEs were identified, followed by MFA-LIBS to improve the qualitative signatures of the elements of interest. MFA-LIBS also assists in confirming signal enhancement for Sm and Gd, which were unidentified with a conventional LIBS setup. Quantitative analysis was performed using a calibration-free and magnetic-field-assisted LIBS (CF-MF-LIBS) method. La, Ce, and Nd concentrations were estimated to be from 1 to 3 wt.%, whereas Sm and Gd were detected within 0.5 wt.%. The results obtained using CF-MF-LIBS were compared with those obtained using the X-ray fluorescence spectroscopy (XRF) technique, showing good agreement between the LIBS/XRF techniques. Further, the limit of detection (LOD) of the REEs using in-house prepared samples was estimated, and the results were compared with those previously reported in the literature. Furthermore, classification analysis of REE ores based on compositional variations was achieved using principal component analysis (PCA). The first two principal components (PCs) with maximum spectral variance, such as PC1~74.5% and PC2~14.5%, were considered for the clustering, and ellipses with 95% confidence using major (x) and minor (y) axes were created to explore outliers. Therefore, the CF-MF-LIBS method in combination with PCA demonstrates a rapid, robust, and effective methodology for the detection, quantification, and classification investigation of REE-bearing ores. Full article

This paper presents the results of the preparation and electrical characterization of Ru–Si–O thin-film nanocomposites deposited by magnetron sputtering (pDC) with varying oxygen content ranging from 0% to 50%. Measurements were conducted over a wide frequency range of 50 Hz–5 MHz and temperatures of 20–373 K. Conductivity analysis revealed that DC conduction occurs at low frequencies (≤10³ Hz), while an increase in conductivity associated with electron tunneling mechanisms is observed at higher frequencies. The determined charge transport activation energies range from 3 × 10⁻⁴ eV for the oxygen-free sample to 6 × 10⁻² eV for the high-oxygen samples, indicating a significant effect of composition on the conduction mechanisms. In samples containing 30% and 50% oxygen, two characteristic frequency ranges for the activation of transport processes were observed (e.g., ~10²–10³ Hz and 10⁴–10⁶ Hz), suggesting the coexistence of multiple tunneling mechanisms. Phase angle analysis revealed a transition from values near –90° at 151 K to values near 0° at 333 K, characteristic of parallel RC systems. The minimum dielectric loss tangent occurs in the range of 10³–10⁵ Hz, corresponding to Maxwell–Wagner relaxation. The dispersion coefficient α reaches maximums in two frequency ranges, decreasing with increasing oxygen content. EDS analysis showed a decrease in Ru content from ~24.9 at.% (0% O₂) to ~0.7 at.% (50% O₂) and an increase in oxygen content to ~78 at.% at 10% O₂. The results confirm the transition from metallic conduction to tunneling and hopping mechanisms with increasing oxidation state of the structure. Full article

Emerging contaminants (ECs) and microplastics (MPs) are increasingly detected in surface waters, wastewaters, and drinking water, often as complex mixtures, transformation products, and particle-associated burdens that challenge routine monitoring. This critical review examines current analytical strategies for the detection and characterization of both molecular and particulate emerging contaminants in aquatic systems, with particular emphasis on their relevance to environmental and human health risk assessment. For molecular ECs, targeted LC–MS/MS and GC–MS and GC–MS/MS approaches are evaluated alongside high-resolution mass spectrometry (HRMS)-based suspect and non-target screening, retrospective data mining, and transformation-product elucidation. For MPs, particle-resolved vibrational spectroscopy including µ-FTIR and µ-Raman is critically assessed in comparison with complementary thermal analysis methods, such as pyrolysis–GC–MS and thermal extraction–desorption GC–MS (TED–GC–MS). Particular attention is given to the influence of sampling design, matrix-adapted sample preparation, analytical confidence, and method-dependent size and polymer coverage on data quality and interstudy comparability. The review further highlights the risks of ECs in relation to exposure pathways, mixture effects, and the potential carrier role of MPs for ECs, additives, and microorganisms. Finally, key priorities are identified for next-generation monitoring frameworks, including harmonized workflows, transparent confidence reporting, and stronger integration of analytical evidence with fate, exposure, and risk assessment. Full article

The antifoaming performance of natural gas desulfurization solvents is critical for maintaining product gas quality and ensuring the safe operation of processing units. Hydrocarbon impurities can enter amine solutions through feed-gas entrainment, wellhead flowback carryover, and leakage of equipment lubricants. These contaminants may gradually accumulate in the solvent system and become a significant contributor to foaming. To address the industrial demand for rapid quantitative determination of hydrocarbon contaminants in desulfurization solvents, this study investigates in-service UDS-series solvents and representative samples collected from a natural gas purification plant in western Sichuan. NMR spectroscopy and GC-MS analyses reveal that the impurities are predominantly n-alkanes in the C₁₃-C₁₈ range, based on which a corresponding reference standard oil was prepared. COSMO-RS calculations combined with molecular interaction analysis identify n-hexane as the optimal extraction solvent. The ultraviolet spectrophotometric method commonly used to determine hydrocarbons in environmental water samples shows limited sensitivity to long-chain n-alkanes and requires strong acid pretreatment that disrupts the amine solvent matrix, rendering it unsuitable for UDS solvents. In contrast, the n-hexane extraction-GC-FID method showed good linearity, precision, and accuracy, meeting engineering analytical requirements for monitoring hydrocarbon contamination in MDEA-based UDS desulfurization solvents. Full article

Reagentless glucose biosensors with redox mediator—polymerized 1,10-phenanthroline-5,6-dione (pPD)—were developed and electrochemically investigated. Three types of biosensors based on graphite rod (GR) electrodes modified by (i) 13 nm of gold nanoparticles (AuNPs), (ii) electrochemically synthesized dendritic gold nanostructures (DAuNSs), and (iii) platinum nanostructures (PtNSs) were prepared. All electrodes were modified by glucose oxidase (GOx), and the pPD was polymerized for 2 h. Thus, GR/AuNPs/GOx/pPD, GR/DAuNSs/GOx/pPD, and GR/PtNSs/GOx/pPD electrodes were developed and electrochemically characterized. The electrode without noble metal nanostructures (GR/GOx/pPD) was used as the control. The biosensor based on the GR/DAuNSs/GOx/pPD electrode exhibited the best performance, with the sensitivity of 2.58 μA/(mM cm²), the linear range up to 93.7 mM, the limit of detection 0.182 mM, the reproducibility and repeatability of 4.99 and 4.80%, and the storage stability (50% of initial current responses (t_1/2)) for up to 19 days. The achieved high resistance to interfering materials enabled precise glucose detection in real samples, including human serum and beverages. The technological solutions presented in this paper are anticipated to provide opportunities and benefits of developing novel enzymatic reagentless glucose biosensors based on noble metal nanostructures for use in clinical assays and general diagnostics, including blood glucose monitoring in people with diabetes. Full article

Latent fingerprint development on rough non-porous substrates using fingerprint powders remains challenging because surface microstructures reduce particle-adhesion selectivity and weaken the contrast between ridges and the background. In this study, Cs${}_2$NaBi${}_{0.6}$Er${}_{0.4}$Cl${}_6$ double-perovskite nanoparticles were prepared by a solvothermal method and investigated as fingerprint-development particles for latent fingerprints on frosted plastic substrates. Structural characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) indicated that Er${}^{3+}$ was incorporated into the host matrix and that the product consisted of spherical nanoparticles with smooth surfaces, relatively uniform particle-size distribution, and good dispersibility. Comparative experiments involving 40 categories of latent fingerprint samples showed that the Cs${}_2$NaBi${}_{0.6}$Er${}_{0.4}$Cl${}_6$ nanoparticles outperformed conventional powders in developing fingerprints on frosted plastic substrates. Quantitative grayscale analysis using Image J 1.53K and Origin 2024 further showed that the development contrast, expressed as the D value, reached 51.21 for sebum-rich fingerprints and 35.87 for oil-contaminated model fingerprints, both of which were higher than those obtained with the other three powders. Because the fluorescence of Cs${}_2$NaBi${}_{0.6}$Er${}_{0.4}$Cl${}_6$ under UV excitation was weaker than that of the commercial red fluorescent powder, we attribute the improved development performance mainly to selective adhesion of the particles to fingerprint residues rather than to fluorescence intensity alone. In addition, the material maintained good performance for aged fingerprints within 10 days and for developed fingerprints stored for up to 8 days. These results suggest that selective residue-affinitive adhesion, possibly assisted by the hydrophilic or moisture-affinitive nature of the ionic double-perovskite particles, plays an important role in improving fingerprint development on rough non-porous substrates. This study provides a physical perspective for latent fingerprint development on rough non-porous substrates and broadens the forensic-science application of lead-free double-perovskite nanomaterials. Full article

Water pollution caused by antibiotics is a growing problem. Therefore, photodegradation by efficient catalysts is an environmentally friendly technology that can effectively degrade organic pollutants in water. In this work, a method was innovatively used to prepare a ternary heterostructure of plasmon-enhanced Ag-CuO/TiO₂. The composite was synthesized through a facile stepwise strategy involving the formation of CuO nanorods, TiO₂ coating, and subsequent deposition of Ag nanoparticles on their surface using AgNO₃, enabling intimate interfacial contact among the different components. The prepared samples were characterized by XRD, HRTEM, XPS, and UV-Vis. The chemical composition of the composite Ag-CuO/TiO₂ showed a Cu/Ti atomic ratio of 2.58, as well as a Ag/Cu ratio of 0.91. The UV-Vis spectrum reveals the largest absorption peak at 550 nm for the composite Ag-CuO/TiO₂. The prepared Ag-CuO/TiO₂ composites were applied to the visible-light degradation of tetracycline hydrochloride, with the photocatalytic degradation rate reaching 80.7% under the optimal conditions within 60 min, which is significantly better than CuO and CuO/TiO₂ without silver nanoparticles. Capture experiments indicated that h⁺ are involved during the course of the photodegradation and that h⁺ are the main active substances. Furthermore, the proposed mechanism for the photodegradation of the Ag-CuO/TiO₂ composites is given. It has potential applications in the treatment of organic pollutants in water. Full article

This study aimed to establish a rapid analytical method for the determination of 69 pesticide residues in Platycodonis Radix using GC-MS/MS and UHPLC-MS/MS, as well as carry out a dietary risk assessment on 42 batches of Platycodonis Radix samples collected from different geographical origins. Samples were prepared using the QuEChERS method, followed by high-speed centrifugation and membrane filtration, and the target pesticides were analyzed in selected reaction monitoring (SRM) mode via GC-MS/MS and in multiple reaction monitoring (MRM) mode via UHPLC-MS/MS. Among the 42 tested batches of Platycodonis Radix samples, 3 out of 27 pesticide compounds were detected via GC-MS/MS screening, while only 1 pesticide compound was positive from the 42 compounds determined via UHPLC-MS/MS, and the risk assessment results demonstrated that both chronic and acute dietary exposure risks of all detected pesticides were considerably lower than 1. Full article

Electrochemical sensing provides an alternative approach for the trace detection of bioactive substances in fruits. However, the complex matrix in fruit tissues, the coexistence of multiple active components, and the varied pH environments limit the sensing performance and accurate quantitative detection of conventional electrochemical sensors. Herein, a dual-mode electrochemical sensor based on a Co₃O₄@N-MWCNTs modified glassy carbon electrode was developed for the sequential detection of quercetin, rutin, and glucose in fruits under acidic and alkaline conditions. The as-prepared electrode exhibited improved charge transfer efficiency and favorable electrocatalytic activity toward the three target analytes. Under optimal conditions, the sensor displayed wide linear ranges of 0.5~70 μM for quercetin and 0.5~5 μM for rutin in acidic environment, with low detection limits of 0.124 μM and 0.045 μM, respectively. In alkaline environment, the detection limit for glucose was determined to be 8.86 μM. Moreover, four combined machine learning models with feature selection algorithms were established, among which the CARS-RFE+RFR model achieved the best prediction accuracy and robustness for multicomponent quantification. Furthermore, the proposed sensing system was applied to the rapid determination of quercetin, rutin, and glucose in real litchi samples, with recoveries ranging from 98.4% to 105.4%. This study provides a feasible electrochemical strategy for multicomponent detection in complex plant matrices, showing good applicability for rapid on-site analysis in agricultural and food-related applications. Full article

1-Methylnaphthalene and the products of hydrogenation exhibit a high hydrogen storage capacity (6.6 wt.%), which makes them extremely promising as liquid organic hydrogen carriers. In this work, effective monometallic catalysts, 15Ni/Al₂O₃, 15Ni/Al₂O₃-SiO₂, and 15Ni/Sib-ox, were synthesized and first investigated for hydrogenation of 1-methylnaphthalene to 1-methyldecalins. The prepared catalysts were characterized using a set of physicochemical analysis methods: SEM-EDX, TEM, XRD, N₂ adsorption–desorption, FTIR and UV-vis-DRS. The catalytic activity of the samples in the hydrogenation reaction of 1-methylnaphthalene (100 min, 4 MPa, 240 °C) was studied in comparison to the traditional catalyst of hydrogenation, Ni Raney. The 15%Ni/Sib-ox catalyst showed a 100% conversion and high selectivity of 85.2% with respect to the target product 1-methyldecalins, while in the presence of Ni Raney, a selectivity of 74.3% was achieved with complete conversion of the substrate. Full article

Background: Live-attenuated Listeria monocytogenes (Lm) vectors are a clinically validated cancer immunotherapy platform, but translation requires reproducible, clinically realistic workflows for dose preparation and infusion. For live bacterial products, in-use stability and device compatibility can drive dose variability through adsorption, settling, and device losses. Methods: We developed and GMP-manufactured an attenuated Lm vaccine expressing human GUCY2C (Lm-GUCY2C) and performed translational characterization, including construct verification and immunogenicity readouts, and defined the administration-focused in-use stability and device compatibility. Post-thaw stability was assessed in primary cryovials and during preparation and delivery from 250 mL saline infusion bags using standard clinical devices (syringes/needles, filter-free IV tubing) and OnGuard2 closed-system components. Samples were collected over 24 h at room temperature, and viable Lm-GUCY2C were quantified by CFU recovery. Results: Lm-GUCY2C remained stable in thawed cryovials for 24 h with no significant CFU loss. High-dose infusion bags (3 × 10⁹ CFU/bag) maintained CFU recovery through 6 h, whereas low-dose bags (3 × 10⁸ CFU/bag) exhibited significant losses beginning at 3 h, supporting a practical in-use window of up to 2 h for low-dose preparations. OnGuard2 intravenous (i.v.) connectors did not measurably affect CFU recovery, while OnGuard2 vial adapters reduced recovery. Conclusions: This work provides an end-to-end, translationally focused characterization of a GMP-manufactured Lm cancer vaccine, including clinically actionable in-use handling constraints and device compatibility. These data define preparation and administration guardrails (notably, time-to-infusion limits for low-dose bag preparations) that can improve dose accuracy and reproducibility in clinical testing. Full article

The Listán Negro cultivar, a red grape variety endemic to the Canary Islands, has been traditionally characterized by limited color stability, often leading to significant pigment loss during early storage. The present study investigates the efficacy of caffeic acid as a hydroxycinnamic cofactor for copigmentation when it is introduced during the post-fermentative stage in young, lightly colored red wines. Ninety young red wine samples were prepared using a factorial design. Caffeic acid was added at four concentrations, both independently and in combination with glucose, and was monitored over 158 days. Initial spectrophotometric analysis revealed a dose-dependent hyperchromic effect, with color intensity increasing by up to 12.8% for caffeic acid alone and 15.9% when combined with glucose. Accompanying bathochromic shifts (1–3 nm) were consistent with copigmentation interactions. Although the effect decreased over time at lower concentrations, doses ≥ 480 mg/L maintained improved color retention after storage. The addition of glucose alone did not improve color stability and showed a transient chromatic response. These results indicate that post-fermentative addition of caffeic acid provides a short-term enhancement of color intensity in low-anthocyanin red wines; however, this effect is strongly concentration-dependent and decreases over time, thereby identifying a threshold for persistent post-fermentative copigmentation. Full article