Search Results (28,808)

Objectives: Patient information regarding postoperative recovery after percutaneous nephrolithotomy (PCNL) and retrograde ureterorenoscopy (URS) remains limited. This study aimed to characterize recovery patterns following these procedures to improve patient counseling. Methods: In this prospective multicenter study, adult patients undergoing URS or PCNL for renal stones were included at an academic center, a teaching hospital, and a regional hospital. Patients completed questionnaires two weeks postoperatively, assessing demographics and recovery outcomes. If recovery was incomplete, follow-up assessments were performed at five and eight weeks postoperatively. Primary endpoints were time to full recovery, duration of pain, and fatigue. Results: Seventy-one patients completed the questionnaire (response rate 56%): 37 underwent PCNL, and 34 underwent URS. The median time to full recovery was 15 days overall: 15 days after PCNL and 13 days after URS. Median postoperative pain duration was 3 days (4 days after PCNL and 2 days after URS). Fatigue was the most frequently reported complaint at two weeks postoperatively, with a median duration of 9 days overall (12 days after PCNL and 7 days after URS). No clear differences in overall recovery duration were observed between URS and PCNL. However, variability in recovery outcomes was considerable. Conclusions: This exploratory study provides early prospective insight into patient-perceived recovery trajectories following URS and PCNL. No clear differences in overall recovery duration were demonstrated between procedures within the limitations of a small and heterogeneous sample. PCNL may be associated with a longer recovery in selected domains; however, larger studies are required to confirm these findings. The questionnaire requires further validation before clinical implementation. Full article

The dissemination of New Delhi metallo-β-lactamase (NDM)-producing Escherichia coli poses a serious threat to public health. Although increasing attention has been paid to the relationship between temperature and antimicrobial resistance (AMR) transmission, research in China’s Xinjiang region remains scarce. In this study, we conducted a cross-sectional survey of 1914 samples from intensive livestock farms across Xinjiang to characterize the detection rate and antimicrobial resistance profiles of bla_NDM-positive E. coli. Using selective culture, PCR, and 16S rRNA sequencing, we identified 140 bla_NDM-positive E. coli (7.3%), predominantly in northern Xinjiang. The highest detection rate of bla_NDM-positive E. coli was found in Tacheng Prefecture (24.0%), followed by Changji Hui Autonomous Prefecture (4.3%) and Bortala Mongol Autonomous Prefecture (0.6%). No bla_NDM-positive E. coli isolates were detected in Bayingolin Mongol Autonomous Prefecture, Kashgar Prefecture, or from pigeon samples. Binomial logistic regression analysis revealed a significant positive association between regional temperature and the detection rate of bla_NDM-positive E. coli. Genotypic analysis identified 35 distinct resistance gene profiles, with predominant resistance genes including bla_TEM (87.9%), ant(3″)-Ia (97.1%), qnrS (92.9%), tet(A) (95.0%), sul1 (70.0%), sul3 (85.0%), and floR (97.1%); mcr-1 and mcr-8 were not detected. Antibiotic susceptibility tests showed that all isolates were resistant to imipenem and exhibited universal resistance to ampicillin, ceftiofur, tetracycline, florfenicol, and enrofloxacin, whereas the majority remained susceptible to amikacin (99.3%), tigecycline (94.3%), and polymyxin (77.1%). These findings indicate that livestock farms, particularly laying-hen systems in northern Xinjiang, may serve as reservoirs of multidrug-resistant bla_NDM-positive E. coli, and that elevated regional temperature is an environmental factor associated with higher detection rates, underscoring a potential climate-associated risk for the spread of AMR. Full article

The present study introduces a novel two-step multi-analytical approach for studying lustre ceramics, aiming to minimize damage to valuable artifacts. The method combines a completely non-destructive preliminary micro-X-ray fluorescence (micro-XRF) analysis, providing semi-quantitative information and elemental mapping, with micro-destructive transmission electron microscopy (TEM) for detailed nanoparticle (NP) morphology studies on selected areas. Diffuse reflectance spectroscopy (DRS) is also employed as a non-destructive method to quantify lustre colour. This approach was applied to 20 samples of 9th- to 12th-century AD lustre ceramics from the Deraheib site in Northern Sudan. The research aimed to verify the lustre technique, characterize lustre properties (nanoparticle size, colour), and identify the ceramic production center based on glaze composition. The results from micro-XRF and TEM confirmed the presence of silver (Ag) and copper (Cu) in the lustre, with Ag NPs having a median size of 8 nm. Semi-quantitative micro-XRF analysis of the glaze indicated a composition rich in lead and tin oxides (PbO and SnO₂, 5%–15%) and magnesium oxide (MgO, 3%). This composition strongly correlates with published data for lustre ceramic production in Basra, Iraq, suggesting it as the likely origin, and ruling out Fustat, Egypt. Full article

Few-shot remote sensing scene classification aims to accurately recognize unseen scene categories using only a scarce number of labeled samples, which has emerged as a research hotspot in the field of remote sensing image interpretation. However, remote sensing images intrinsically suffer from large intra-class variations, high inter-class similarities, and complex background interferences. Traditional few-shot learning methods typically perform feature metric learning in Euclidean space, making it difficult to capture the non-Euclidean geometric distribution characteristics of remote sensing features, and they often neglect the spatial structural information embedded in feature maps. To address these issues, this paper proposes a novel few-shot remote sensing scene classification method, termed ZSFS-RGBN, which integrates a Zigzag Scanning Feature Sequence with a Riemannian Geometric Barycenter Network. Specifically, ResNet12 is first employed as the backbone to extract deep convolutional feature maps from both the support and query sets. Second, a Zigzag scanning strategy is introduced to reorganize the two-dimensional feature maps into one-dimensional feature sequences, thereby effectively preserving the spatial locality and structural continuity of the features. Third, an autoregressive moving average (ARMA) model is constructed to characterize the spatial dependencies of the feature sequences, and its state parameters are mapped onto a symmetric positive definite (SPD) matrix manifold, enabling the deep semantic representations of remote sensing scenes in a non-Euclidean geometric space. Finally, a Riemannian geometric barycenter network is designed to learn the Riemannian barycenter of each category on the SPD manifold, where a joint loss function is introduced to simultaneously optimize intra-class compactness and inter-class separability. Comprehensive experiments are conducted on three public remote sensing scene datasets: NWPU-RESISC45, UC Merced Land-Use, and WHU-RS19. Experimental results demonstrate that the proposed method consistently outperforms several representative state-of-the-art approaches under both 5-way 1-shot and 5-way 5-shot settings. Furthermore, ablation studies verify the effectiveness of each component within the proposed framework. Full article

CO₂ foam fracturing has emerged as a promising stimulation technology for enhancing permeability and improving production performance in deep coalbed methane (CBM) reservoirs while providing additional potential for carbon utilization. However, the multiscale relationship between local mechanical degradation and macroscopic mechanical deterioration and fracture instability induced by CO₂ foam treatment remains insufficiently understood. In this study, four candidate coal samples originating from the Carboniferous–Permian No. 8+9 coal seam system were first comparatively characterized. Based on petrographic characteristics, mineralogical composition, and specimen integrity, representative bright coal and semi-dull coal samples from the Lüliang mining area were selected for subsequent multiscale mechanical investigations. Based on petrographic characteristics, mineralogical composition, and specimen integrity, representative bright coal and semi-dull coal samples from the Lüliang mining area were selected for petrographic analysis, X-ray diffraction (XRD), nanoindentation, conventional triaxial compression, and cracked chevron-notched Brazilian disc (CCNBD) fracture toughness tests. Coal specimens were immersed in CO₂ foam under reservoir-relevant conditions (50 °C, 20 MPa, foam quality of 65%) for different durations (0–6 days), and the coupled evolution of micromechanical properties, macroscopic mechanical behavior, and fracture resistance was evaluated. The results indicate that both coal types exhibit pronounced heterogeneity in maceral composition and mineral distribution. Bright coal is characterized by high vitrinite content and low mineral abundance, whereas semi-dull coal contains higher proportions of inertinite and minerals. Nanoindentation results reveal that mineral-rich regions possess significantly higher Young’s modulus and hardness than organic-matter-rich regions, highlighting pronounced micromechanical heterogeneity within the coal matrix. With increasing immersion time, the micromechanical properties of both coals exhibit a two-stage evolution characterized by rapid initial deterioration followed by a gradual stabilization trend. After 6 days of immersion, the average Young’s modulus and hardness of bright coal decreased by 40% and 30%, respectively, whereas those of semi-dull coal decreased by 30% and 17%. Simultaneously, macroscopic mechanical properties and fracture resistance continuously declined, with fracture toughness reductions of 74% and 55% for bright coal and semi-dull coal, respectively. Compared with semi-dull coal, bright coal exhibited higher damage sensitivity, evolving from dominant single-fracture failure to granular fragmentation, whereas semi-dull coal maintained a multi-crack composite shear failure mode. Combined micromechanical and macroscopic observations suggest that the observed mechanical deterioration may be associated with coupled effects of fluid–coal interaction, matrix softening, and progressive damage evolution. Although pore and crack evolution were not directly observed, the results suggest that coal structure plays an important role in governing damage transfer across scales and thereby influences fracture behavior and mechanical weakening. These findings provide insight into the multiscale mechanical response of coal under CO₂ foam treatment and may support the optimization of stimulation strategies for deep CBM reservoirs. Full article

Background/Objectives: Knee injuries and overuse-related disorders are common among athletes participating in jumping sports such as handball and basketball. Musculoskeletal ultrasonography is increasingly used for the assessment of knee pathology; however, evidence regarding the prevalence and clinical relevance of ultrasonographic abnormalities in young athletes remains limited. The aim of this study was to investigate the prevalence of ultrasonographic knee abnormalities in young male handball and basketball athletes and to examine their association with pain intensity. Methods: A cross-sectional observational study was conducted between June 2025 and June 2026 and included 69 competitive male athletes (35 handball players and 34 basketball players). All participants underwent bilateral knee ultrasonographic examination using a standardized assessment protocol and completed a questionnaire regarding demographic and training characteristics. Knee pain intensity was evaluated using the Visual Analogue Scale (VAS). Comparisons between sports were performed using χ² and t-tests, while associations between participant-level ultrasonographic findings and pain were evaluated using independent-samples t-tests (or Mann–Whitney U tests, as appropriate), with Cohen’s d effect sizes and exploratory multivariable linear regression. Sensitivity analyses stratified by sport were additionally performed. Results: Patellar tendinopathy was the most prevalent ultrasonographic abnormality (21.0%), followed by medial meniscal abnormality (15.9%) and infrapatellar bursitis (13.0%). Athletes with patellar tendinopathy, medial meniscal abnormality, or infrapatellar bursitis had significantly higher VAS pain scores than athletes without the corresponding ultrasonographic abnormality. Patellar tendinopathy demonstrated the strongest association with participant-reported pain (VAS: 4.1 ± 1.3; Cohen’s d = 1.24; p < 0.001). Handball athletes exhibited a significantly higher prevalence of patellar tendinopathy than basketball athletes (34.3% vs. 11.8%; OR = 3.90, 95% CI: 1.09–13.95; p = 0.027). In multivariable regression analysis adjusted for age, BMI, sport type, previous knee injury, and weekly training volume, patellar tendinopathy (β = 1.34, p < 0.001), medial meniscal abnormality (β = 0.70, p = 0.017), and infrapatellar bursitis (β = 0.54, p = 0.046) remained independently associated with higher pain scores. The regression model explained 39% of the variance in VAS pain scores (R² = 0.39). Conclusions: Ultrasonographic knee abnormalities are common among young male handball and basketball athletes and are significantly associated with pain intensity. Because ultrasonography has limited ability to characterize intra-articular pathology, particularly the menisci, the ultrasonographic abnormalities identified in this study should not be interpreted as definitive diagnoses, and MRI remains the reference imaging modality when comprehensive evaluation of intra-articular pathology is clinically indicated. Patellar tendinopathy was the most prevalent ultrasonographic abnormality and was most strongly associated with pain intensity. These findings support the use of musculoskeletal ultrasonography as a complementary imaging modality alongside clinical assessment in the evaluation of symptomatic athletes. However, prospective longitudinal studies are required to determine whether these ultrasonographic abnormalities have prognostic value for future pain, functional limitation, or time-loss injury. Full article

Chemical contamination of milk represents a relevant food safety concern, particularly in countries where systematic monitoring programs are still limited. In Algeria, information on human exposure to aflatoxin M₁ (AFM₁) and per- and polyfluoroalkyl substance (PFAS) contamination remains fragmented or lacking. This study assessed the occurrence of AFM₁ and 17 PFAS in cow and goat milk and explored farm-level management practices potentially influencing contamination. Bulk-tank milk samples were collected from 26 dairy cattle and 11 dairy goat farms. Farm characteristics, including feeding strategies, water sources, grazing practices, and herd size, were recorded using structured questionnaires to characterize farm-level practices and explore their potential association with contamination patterns. AFM₁ was detected in all samples. In cow milk, 96.1% exceeded the EU limit (0.05 µg/kg), with concentrations ranging from 0.048 to 0.410 µg/kg (mean: 0.102 µg/kg), although none exceeded the Codex Alimentarius limit (0.50 µg/kg). Goat milk showed a lower prevalence of samples above the EU limit (36.4%), but higher concentrations were observed (range 0.030–0.578 µg/kg; mean 0.193 µg/kg), with two samples (18.2%) exceeding the Codex limit. PFAS contamination was generally low: 73.0% of cow and 64.0% of goat samples were below detection limits, with only PFBS (cow milk) and PFDA (goat milk) quantified above LOQ. Because of the limited number of farms and the single sampling period, no robust associations could be established between farm-level variables and contaminant concentrations. This preliminary study provides an exploratory overview of AFM₁ and PFAS occurrence in bovine and goat bulk milk from the sampled Algerian farms. These findings reveal widespread AFM₁ contamination within the investigated farms, consistent with possible feed-borne AFB₁ exposure, whereas PFAS occurrence appeared sporadic and generally low. Full article

Background/Objectives: Tripterygium glycosides (TG) are used to treat inflammatory and autoimmune diseases, but their clinical application is limited by toxicity and the lack of process-responsive quality markers. This study examined whether roasting and dealkalization remodel the TG metabolite profile and alter the post-dose serum profile of circulating prototype constituents. Methods: Self-prepared TG, roasted TG (RTG), roasted–dealkalized TG (RDTG), and five marketed products were profiled by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Seven representative compounds were quantified by validated high-performance liquid chromatography (HPLC). Rat serum after oral administration was analyzed to compare circulating prototype constituents. Results: We characterized 243 constituents in material samples and 63 circulating prototype constituents in serum. Roasting primarily reshapes the profiles of diterpenoids and triterpenoids. Celastrol was not detected in the RTG and RDTG material samples, nor in the corresponding single-time-point serum profiles under the current analytical conditions. In contrast, wilforlide A exhibited an increase in material samples. Dealkalization preferentially reduced alkaloid-related constituents, including wilforine in material samples and tripterygiumine T in serum. Conclusions: Integrated material profiling, targeted quantification, and serum prototype analysis identified candidate process-responsive markers for processed TG preparations. Because the serum study was based on relative signal intensities rather than full pharmacokinetics, these markers require further pharmacokinetic and toxicological validation. Full article

This study aimed to measure mRNA and miRNA expression profile in corneal impression cytology (IC) samples from patients with congenital aniridia (CA) and healthy controls, and to elucidate the key genes and signaling pathways involved in aniridia-associated keratopathy (AAK). Corneal IC samples were collected from 14 patients with CA and 14 healthy controls. RNA sequencing was performed to identify differentially expressed genes (DEGs) and miRNAs. Correlations with age and AAK grade were analyzed, selected miRNAs were validated by RT-qPCR, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to characterize biological functions and pathways. A total of 695 DEGs and 19 differentially expressed miRNAs were identified. KRT24 expression was negatively associated with age, whereas LY6D expression positively correlated with AAK grade. Several miRNAs were linked to disease severity, including positive correlations for miR-224-5p, miR-224-3p, and miR-452-5p, and negative correlations for miR-204-3p, miR-181b-5p, and miR-181a-5p. RT-qPCR confirmed significant downregulation of miR-204-5p and miR-138-5p in aniridia samples. Functional enrichment analyses showed that DEGs were mainly involved in cell adhesion, extracellular matrix remodeling, inflammatory and immune responses, and neural-related processes. Target genes of dysregulated miRNAs were enriched in transcriptional regulation, cell proliferation, apoptosis, and migration, with significant involvement of PI3K-Akt, AGE-RAGE, and EGFR signaling pathways. Corneal epithelial cells from patients with CA exhibit coordinated mRNA and miRNA dysregulation associated with extracellular matrix disruption, inflammation, and altered signaling pathways. These findings improve understanding of AAK pathogenesis and identify potential biomarkers and therapeutic targets. Full article

In hybrid wire arc additive manufacturing with interlayer friction stir processing (UAMFSP), refined microstructures are produced in aluminum alloy builds; however, the thermal parameters governing layer-resolved defect evolution remain poorly understood. In this study, a correlative mechanistic framework is presented in which post-peak cooling rate is identified as a plausible controlling factor for porosity evolution in UAMFSP Al 4043 three-layer walls. A multi-scale characterization is performed by employing infrared thermography, quantitative optical grain morphology analysis (N  =  10,346 grains, Layers 1–3), scanning electron microscopy from 250× to 35,000×, and image-based porosity quantification from calibrated SEM fields. This primary quantitative comparison is established between L1 and L3 only; Layer 2 is excluded from the 250× quantitative analysis owing to its thermally distinct cooling regime and is treated separately. A counterintuitive layer-dependent porosity gradient is reported, wherein the upper layer (L3) exhibited 80% higher porosity (2.90 ± 1.18%) and 107% higher pore density (4283  ±  900 pores/mm²) than the bottom layer (L1), despite recording a 26% lower peak FSP surface temperature (195.1 vs. 263.2 °C) (n = three fields per layer; Cohen’s d ≈ 1.7). Based on these results, the post-peak cooling rate, rather than peak temperature, is identified as a plausible controlling factor for void consolidation quality, as evidenced by the observation that L3 cools at −12.3 °C/s versus −16.2 °C/s for L1, which is consistent with prolonged high-temperature dwell and reduced plastic-flow-assisted pore closure in the upper layer. The anomalously rapid cooling of L2 (−46.9 °C/s), attributed to a bilateral thermal gradient between the substrate and the air-cooled free surface, places it in a thermally distinct regime; accordingly, L2 is utilized exclusively for high-magnification SEM characterization in this study. High-magnification SEM imaging (12,000×–35,000×) revealed a frequent spatial co-location of sub-micron pores with fragmented Al–Si eutectic particles, which is consistent with preferential void persistence near particle–matrix interfaces. Grain morphology also exhibits non-monotonic evolution with build height, with mean circularity following the order L3 (0.645) > L1 (0.621) > L2 (0.569), and the equiaxed grain fraction ranging from 25.5% (L2) to 36.1% (L3) (ANOVA: F = 56.2, p = 5.15 × 10⁻²⁵), while the mean equivalent grain diameter remained below 3.4 μm across all layers. Overall, the outcomes of this study establish post-peak cooling rate, rather than peak temperature, as a plausible controlling factor for void consolidation quality in UAMFSP builds, with the caveat that complete causal isolation requires controlled single-variable experiments. These outcomes are presented as a first mechanistic framework for this class of hybrid process and are intended to motivate targeted controlled experiments, subsurface thermal characterization, and expanded porosity sampling in future investigations of multi-layer additive–deformation manufacturing of Al-based alloys. Full article

Pleurotus pulmonarius (Fr.) Quél. is a commercially important edible mushroom recognized for its nutritional and nutraceutical value. However, the influence of alternative agricultural waste substrates on its biochemical composition remains insufficiently characterized. This study investigated the effect of four cultivation substrates, coconut waste (PpC), paddy husk (PpP100), paddy husk supplemented with sawdust (PpP20) and rubberwood sawdust as control (PpS), on the macro- and microelement profile, secondary metabolite composition, and antioxidant activity of P. pulmonarius fruiting bodies. Analytical methods included ICP-MS and FAAS for elemental analysis; GC-MS for fatty acid, carbohydrate and phenolic profiling; Kjeldahl method for total protein; FTIR spectroscopy for structural characterization; and four complementary antioxidant assays (DPPH, ABTS, CUPRAC, FRAP). Coconut waste substrate promoted the highest protein accumulation and elevated concentrations of iron, zinc, and specific phenolic acids (vanillic, protocatechuic). Paddy husk-based substrates favored carbohydrate accumulation, particularly trehalose, while sawdust supported the greatest lipid content, dominated by linoleic acid. Potassium was the predominant macroelement across all variants. Antioxidant activity was highest in PpP100 and PpC across all four assays. FTIR confirmed a mushroom-specific polysaccharide, protein, and lipid profile in all samples. The results demonstrate that agricultural waste represents sustainable, value-added alternatives to conventional sawdust, capable of maintaining or enhancing the nutritional and nutraceutical quality of oyster mushrooms to enhance agricultural production. Full article

This study investigates the spatial variability of benthic foraminiferal assemblages across the shoreface–inner shelf transition of the Porto Pino coastal system (SW Sardinia, western Mediterranean). Porto Pino is a microtidal, wave-dominated embayment characterized by an environmental gradient extending from siliciclastic shoreface sands to mixed bioclastic sediments associated with the Posidonia oceanica meadow. A total of 33 sediment samples were analyzed for grain size, benthic foraminiferal assemblages, morphotypes and diversity indices. Cluster analysis and Principal Component Analysis (PCA) were used to investigate the spatial variability of the assemblages. Three main benthic foraminiferal assemblages were identified, each corresponding to a distinct benthic habitat: shallow unvegetated shoreface sands, a transitional zone near the upper limit of the P. oceanica meadow, and deeper mixed bioclastic sediments associated with its lower boundary. The distribution of the foraminiferal assemblage reflects the combined influence of hydrodynamic energy, substrate composition, water depth, and proximity to the meadow. Diversity indices indicate generally low-stress environmental conditions, whereas morphotype composition reflects changes in habitat structure and substrate characteristics along the shoreface–inner shelf gradient. These results demonstrate that benthic foraminifera effectively track environmental and sedimentological gradients in Mediterranean embayed systems and highlight their value for environmental reconstructions and biomonitoring applications. Full article

Although commercial vaccines against porcine circovirus type 2 (PCV2) have been widely implemented globally, PCV2 remains endemic in swine populations, accompanied by ongoing genotype replacement. Meanwhile, the emergence of novel porcine circoviruses (PCVs), including PCV3 and PCV4, has further complicated the prevention and control of porcine circovirus-associated diseases (PCVAD). This study systematically characterized the epidemiological patterns and genetic diversity of PCVs circulating in Eastern China. A total of 739 clinical samples collected between 2010 and 2016 were screened for PCV2. Additionally, 653 samples obtained during 2023–2024 were analyzed using a triplex real-time quantitative PCR (qPCR) assay for the simultaneous detection of PCV2, PCV3, and PCV4. Full-genome amplification and sequencing were subsequently performed on all PCR-positive samples. Epidemiological analysis revealed an overall PCV2 positivity rate of 37.62% during 2010–2016. In the 2023–2024 cohort, the positivity rates for PCV2 and PCV3 were 35.99% and 16.39%, respectively, with a co-infection rate of 10.26%. Notably, no PCV4-positive samples were detected. Phylogenetic analysis demonstrated that PCV2d is the predominant genotype in Eastern China. Furthermore, PCV2g strains were identified in clinical samples for the first time in mainland China, while PCV3b were determined to be the dominant circulating subtype of PCV3. Multiple critical amino acid substitutions were identified within the neutralizing epitopes of the PCV2 Cap protein, and a recombination event involving a PCV2d vaccine strain and a PCV2c reference strain was detected. In contrast, the PCV3 genome exhibited a high degree of genetic conservation. Collectively, these findings expand the molecular epidemiological landscape of PCVs in Eastern China and elucidate the evolutionary dynamics of circulating PCV strains, providing important insights for the development of next-generation vaccines and region-specific PCVAD control strategies. Full article

The introduction of a quantitative definition of fish freshness enables the determination of the remaining storage time of raw fish materials. To measure this value, a virtual array of electrochemical chemotransistor-based chemical sensors was developed. The electrolyte used to electrically connect the four measurement electrodes and the reference electrode was optimized. To achieve the high stability, high electrochemical activity of chemosensitive material, and reversible potential of the silver/silver chloride reference electrode, a chloride-containing ionic liquid and polymeric acid mixture was used as the electrolyte. Polyaniline in different redox states was applied as the chemosensitive material with electrically controlled affinity. First, the sensor was evaluated for trimethylammonium detection, and then it was applied to fish samples. Unlike the response observed for trimethylammonium, the sensor’s response to fish samples exhibited complex, non-exponential kinetics and a non-monotonic dependence on the storage duration of fish samples. To characterize these responses, a set of descriptors was introduced. The storage time was estimated by minimizing the Euclidean distance between the descriptors values obtained from fish samples and those determined during calibration. Based on the quantitative definition of freshness, this approach categorizes the current stage of fish products and predicts the remaining storage duration quantitatively. Full article

The present study reports the application of a gold microelectrode array to determine copper(II) ions by anodic stripping voltammetry (ASV). The microelectrode characterization of the presented working electrode was investigated. Moreover, the way of its preparation ensures its reusability and eco-friendly character, thanks to the use of environmentally benign electrode material. The procedure does not require modification of the surface of the working electrode. Main experimental parameters were optimized, including pH and a concentration of the supporting electrolyte, activation and deposition conditions, and square wave parameters. The calibration graph was linear in the range of Cu(II) concentrations from 2 × 10⁻⁹ to 2 × 10⁻⁷ mol L⁻¹ (with a deposition time of 30 s) and from 5 × 10⁻¹⁰ to 5 × 10⁻⁸ mol L⁻¹ (with a deposition time of 90 s; RSD was 4.7% (n = 3) for a 1 × 10⁻⁸ mol L⁻¹ of Cu(II)). The limit of detection was equal to 1.93 × 10⁻¹⁰ mol L⁻¹ (t_acc = 90 s). The correctness of the developed procedure was successfully checked by analysis of certified reference material and a tap water sample, confirming the possibility of its practical application. Satisfactory recovery values were also obtained during the analysis of an environmental water sample. Full article