Search Results (287)

The increasing prevalence of multidrug resistance (MDR) in Candida species poses a major obstacle to effective antifungal therapy. Since the efflux pumps Cdr1 and Mdr1 are key mediators of the MDR phenotype, particularly by conferring resistance to azoles, their inhibition has emerged as a promising strategy to restore antifungal susceptibility. Bioassay-guided fractionation of Solanum atriplicifolium, selected based on its ability to inhibit Mdr1 and Cdr1, led to the isolation of six previously undescribed acylhexoses, including four acylglucoses, named atriplicifolin A (1), atriplicifolin B (2), atriplicifolin C (3) and atriplicifolin D (4) and two acylinositols, named atriplicifolin E (5) and atriplicifolin F (6). Among these, compounds 3 and 4 successfully restored fluconazole sensitivity in resistant Saccharomyces cerevisiae strains overexpressing Mdr1 (AD/CaMDR1) and Cdr1 (AD/CaCDR1), with greater activity against the latter, with minimum effective concentrations (MECs) of 6.2 and 7.5 µM, respectively. Both compounds also significantly increased the intracellular accumulation of Nile red and rhodamine 6G in AD/CaMDR1 and AD/CaCDR1 strains, again showing a stronger effect in the Cdr1-overexpressing strain, where MEC values ranged from 3.1 to 15.5 µM. Molecular dynamics simulations supported these results by revealing that compounds 3 and 4 displayed higher binding affinity for Cdr1 than fluconazole, Nile red or rhodamine 6G. Furthermore, analysis of the persistence and energetic contribution of individual ligand–transporter interactions over time, particularly within specific regions of the transporter, provided valuable insights for the rational design of novel inhibitors. Overall, these findings identify compounds 3 and 4 as promising scaffolds for the development of Mdr1 and Cdr1 modulators aimed at overcoming fungal multidrug resistance. Full article

Background/Objectives: Microplastics (MPs) are emerging environmental contaminants with potential implications for human health. Experimental studies suggest that MPs accumulate in the liver and promote inflammatory and fibrotic changes, but evidence from human tissues remains limited. This study investigated the presence of suspected MP-like particles in post-mortem human liver tissue and their associations with clinical, biochemical, hematological and histopathological parameters. Methods: Post-mortem liver tissue samples were collected from 55 adults. Suspected MP-like particles were extracted using hydrogen peroxide digestion, filtration, Nile Red staining and image-based quantification. Histopathological evaluation assessed inflammation, fibrosis, necrosis and fatty liver degeneration. Polarized light microscopy was used as a supportive morphological assessment method. Statistical analyses included Mann–Whitney U tests, Fisher’s exact tests and Spearman correlation analysis. Results: Detectable hepatic suspected MP-like particles were identified in 9 of 55 individuals (16.4%). Individuals with detectable suspected MP-like particles had significantly lower alanine aminotransferase (ALT) levels and leukocyte counts. The hepatic suspected MP-like particle burden showed weak positive correlation with liver fibrosis and inflammation and weak inverse correlation with ALT levels and leukocyte count. Fisher’s exact test showed that liver fibrosis and liver inflammation were significantly associated with detectable hepatic suspected MP-like particles, with higher unadjusted odds observed in the corresponding 2 × 2 contingency tables. No statistically significant associations were found for liver necrosis or fatty liver degeneration. Conclusions: Detectable suspected MP-like particles were identified in post-mortem human liver tissues and were more closely associated with fibrotic and inflammatory histopathological changes than with routine biochemical abnormalities. Larger studies using standardized detection methods are needed to confirm these results. Full article

This study compared floating raft and media bed aquaponic systems, assessing fish growth, plant growth, and system performance between common system designs. The study consisted of two trials utilizing six replicated aquaponic systems. In each trial, three of the systems were floating rafts (1514 L/system) and three were media beds (1136 L/system). In Trial 1, basil (Ocimum basilicum, ‘Genovese’) and green salanova lettuce (Lactuca sativa, ‘Salanova Green’) plants were stocked, and, in Trial 2, green and red salanova lettuce (Lactuca sativa, ‘Salanova Red’) plants were stocked. Nile tilapia (Oreochromis niloticus) were used in both trials. In Trial 1, no differences (p > 0.05) in fish or basil growth between floating raft (0.28 ± 0.10% daily growth; 55.0 ± 21.2 g/plant fresh weight (FW); 1106 ± 72 g total biomass/system) and media bed systems (0.29 ± 0.20%; 42.1 ± 7.8 g/plant FW; 879 ± 160 g total biomass/system) were found. However, in Trial 1, floating raft systems produced a significant (p < 0.01) increase in green salanova lettuce (123 ± 21.9 g/plant FW; 3327 ± 256 g total biomass/system) as compared to plants grown in media beds (94.4 ± 35.3 g/plant FW; 2,356 ± 260 g total biomass/system). In Trial 2, no differences (p > 0.05) in fish growth between floating raft (0.50 ± 0.13% daily growth) and media bed systems (0.50 ± 0.01% daily growth) were found; however, floating raft systems produced a significant (p < 0.01) increase in both green and red salanova lettuce individual weight (176.0 ± 34.0 g/plant FW; 169.3 ± 43.6 g/plant FW) as compared to media bed systems (79.2 ± 25.3 g/plant FW; 96.4 ± 22.6 g/plant FW). Green lettuce had a significant (p < 0.01) increase in average total biomass within floating raft systems (3662 ± 350 g total biomass/system) as compared to media beds (1576 ± 474 g total biomass/system). This study highlights the need for further investigation into system design and effects on plant and fish growth to allow producers to make informed decisions when planning an operation. Full article

Particles exhibiting fluorescence after Nile Red staining have been increasingly investigated in human biological samples in the context of microplastic exposure, but their clinical relevance remains unclear. In this study, Nile Red-positive microparticles were quantified in whole blood from chronic users of different nicotine-delivery systems and non-user controls. The study included 73 nicotine users, including conventional cigarette smokers, e-cigarette users, and heated tobacco product users, as well as an age- and sex-matched control group. Only participants without diagnosed chronic somatic disease were enrolled. Microparticles were quantified by flow cytometry after Nile Red staining. Associations with age, nicotine dependence assessed with the FTND and FTQ, motivation to quit smoking assessed with the Schneider Motivation Test, and selected hematological and biochemical parameters were also analyzed. In the overall analysis, the mean number of microparticles was higher in nicotine users than in controls, but the difference was not statistically significant (p = 0.38). In subgroup analyses, higher particle counts were observed in conventional cigarette smokers and heated tobacco product users compared with controls. No significant difference was found for e-cigarette users. Higher particle counts were also observed in older participants and in participants with greater nicotine dependence. Participants with higher particle counts more often showed stronger nicotine dependence and lower motivation to quit smoking. These results suggest that circulating Nile Red-positive microparticle counts may differ according to the type of nicotine product used and selected behavioral characteristics. However, the subgroup findings should be interpreted with caution due to the exploratory design and limited statistical power. Full article

Microplastics (MP) are emerging pollutants found in the Veracruz Reef System National Park (PNSAV). They are widely distributed in the aquatic environment and are ingested by organisms either accidentally or because they are mistaken for food. In this article, the author analyses the physicochemical characteristics of reef sediments using visual identification, Nile Red (NR), scanning electron microscopy (SEM), and Energy Dispersive Spectroscopy (EDS) of microplastics found in sediments adjacent to reefs; this allowed us to determine their distribution within the PNSAV. A total of 687 microplastics per kilogram of dry sediment were quantified, including fibres (98.5%), films (1.4%), and fragments (0.01%). The predominant colour was transparent (60.2%), followed by blue (16%) and red (12%). Based on their MP distribution, the sites were classified into two groups: north and south. The sampling stations with the highest concentrations of MP are located in the group of reefs south of the PNSAV, with the Anegadilla Reef being the most affected station. SEM/EDS analyses revealed elemental spectra dominated by carbon and oxygen, which is consistent with the expected elemental composition of polymeric materials. Peaks of chlorine were detected in some MP particles, suggesting the possible presence of chlorinated polymers, such as polyvinyl chloride (PVC). In addition, elements such as titanium, silicon, and nickel were identified, which could be associated with inorganic particles adhering to the surface or with additives commonly incorporated during the manufacture of plastics such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and polyethylene terephthalate (PET). The presence of elements such as titanium and nickel were detected; these are found in additives used in the manufacturing of polymers. Full article

Rapid detection and localization of liquid fuel spills is critical for first responders assessing fire and health hazards, yet current methods require ground-based sampling or specialized instrumentation, limiting their practicality for wide-area emergency response. We present a drone-based passive colorimetric sensor system using test strips impregnated with Nile red, similar to colored confetti. Nile red is a solvatochromic dye that undergoes distinct visible color transitions upon exposure to different liquids. The dye is embedded within a polymer matrix that minimizes leaching while providing high optical contrast between dry, water-exposed, and fuel-exposed states. The sensor strips exhibit solvent-specific colorimetric responses within one minute of exposure, readily detectable by standard RGB cameras mounted on unmanned aerial vehicles (UAVs) at altitudes up to 50 m. Automated classification was validated at 20 m altitude, enabling remote surveillance of contaminated surfaces without specialized equipment. Color-corrected image analysis using Calibrite ColorChecker calibration ensures reliable interpretation under variable field illumination (625–77,000 lux). Systematic laboratory evaluation of twelve fossil and bio-derived fuels revealed characteristic hue shifts that clearly discriminate ethanol-containing gasoline blends from diesel-range fuels. Rather than identifying specific molecules, the method functionally categorizes contamination into gasoline/ethanol blends versus diesel-type fuels, reflecting bulk polarity rather than molecular composition. Field validation confirmed localization and classification of fuel-exposed sensors, achieving F1 scores of 0.94 for gasoline and 0.98 for diesel detection with no false positives in the tested scenarios. This cost-effective and scalable approach provides actionable information on both contamination location and fuel type, crucial for rapid hazard assessment in emergency response scenarios. Full article

Congenital toxoplasmosis, caused by the obligatory intracellular apicomplexan protozoan Toxoplasma gondii, can lead to severe complications during pregnancy, including fetal malformations and spontaneous abortion. In the present study, the anti-T. gondii effects of the natural flavonoid quercetin were evaluated using in vitro, ex vivo, and in silico models. Cell viability and intracellular proliferation of the parasite were determined via colorimetric assays. The lipid droplet assay was analyzed using Nile Red staining, the antioxidant and oxidative stress parameters were determined by biochemical assays, and the cytokine levels were quantified by immunoassays. Our results demonstrated that non-cytotoxic concentrations of quercetin (CC₅₀ > 100 μM) significantly inhibited parasite proliferation (IC₅₀ = 14.10 ± 2.83 μM; SI > 7.09) in an irreversible manner. Quercetin impairs parasite adhesion, invasion, and reinfection capacity. In parallel, quercetin reduced lipid droplet accumulation, restored antioxidant balance by modulating redox biomarkers, and regulated cytokine production, notably increasing IL-4, IL-6, and IL-8 levels. Corroborating the in vitro findings, quercetin significantly reduced T. gondii proliferation in human placental villous explants while preserving tissue architecture and viability. In silico analyses revealed that quercetin binds to the active site of T. gondii hypoxanthine-guanine phosphoribosyltransferase (TgHGPRT) and exhibits favorable pharmacokinetic and drug-likeness properties. Full article

A modified Pitot-tube jet (PTJ) separation pump combines centrifugal phase separation with pressure buildup and enables compact oil–water treatment, where a water-rich stream can be discharged at elevated pressure. This work advances an existing laboratory PTJ configuration toward a turbomachinery-oriented rotor concept for systematic design studies and subsequent field-oriented prototypes. Starting from a centrifuge-like reference configuration without blades that prioritizes separation stability, an impeller with trimmed blades is introduced to increase pressure head while limiting blade interaction with the oil–water interface by operating primarily in the outer, water-rich annulus. Comparative experiments with and without the impeller show a pronounced increase in pressure head, up to about a factor of three at the maximum speed investigated. The results also indicate a purity penalty caused by blade-induced mixing and secondary flows. This exposes the central design trade-off of the PTJ machine. Higher specific work input increases pressure head but can reduce discharge quality. Hydraulic optimization, therefore, needs to be coupled to ppm-level purity constraints. Density-based monitoring lacks resolution in the relevant trace range, and chemical-based analyses are too slow for systematic investigations. An imaging-based fluorescence method using Nile Red as a selective tracer is, therefore, implemented as a rapid analysis tool. High-resolution imaging with automated region of interest evaluation provides a robust calibration from 5–500 ppm for safe, non-fluorescent model oils such as sunflower oil. This enables efficient operating-window mapping and comparative screening of rotor concepts under reproducible conditions. Full article

With the global increase in microplastic pollution, even environments considered pristine have shown signs of being affected by these contaminants. In this context, it becomes essential to conduct studies that identify and quantify the presence of microplastics in remote regions such as Antarctica. This continent is particularly relevant due to its low anthropogenic influence and its essential role in regulating planetary ecosystems and biodiversity. In this study, 49 Antarctic samples were analyzed using pretreatment techniques with NaCl and ZnCl₂ saline solutions, followed by fluorescence microscopy using Nile Red dye to estimate the microplastic abundance index. Both solutions showed good performance in the separation and identification of particles. Approximately 37% of the samples showed contamination by potential microplastics (PMPs), with a higher concentration of particles retained on paper filters and fibers observed in the supernatants. The results indicate that the presence of MPs in Antarctica is irregular and not ubiquitous, differing from other studies that suggest a wider distribution. It is speculated that the observed contamination results from oceanic transport from other regions of the planet and from sources associated with human activities on the Antarctic continent (e.g., tourism and research). Full article

Microplastics (MPs) are emerging contaminants in freshwater ecosystems, yet their ingestion by zooplankton remains poorly documented in large European lakes. This study provides the first evidence of MPs in zooplankton from Lake Como (Northern Italy), a major subalpine lake of ecological and socioeconomic relevance. Using high-resolution digital microscopy (detection limit: 2 µm), we quantified MPs across four sampling years (2016, 2017, 2018, 2025), capturing small size fractions typically overlooked by conventional methods. MPs were consistently detected, with mean concentrations of 0.06 ± 0.08 MPs ind.⁻¹ and 1.14 ± 1.22 MPs mg⁻¹ d.w., values comparable to those reported for freshwater zooplankton worldwide. No significant differences were observed between the lake’s two main branches, supporting a lake-wide interpretation of exposure. Clear seasonal patterns emerged, with higher MPs loads in autumn and winter. These findings highlight the potential for MPs to enter pelagic food webs and contribute to a lake-wide baseline for future harmonized monitoring and polymer-specific assessments. The main limitation of this study is the exclusive quantitative approach, which does not provide qualitative information on polymer composition. Overall, these results underscore the need to integrate zooplankton-based monitoring into freshwater microplastic risk assessment frameworks. Full article

Timely and accurate mapping of tree species is essential for forest resource inventory, biodiversity conservation, and sustainable ecosystem management, particularly in dryland environments where structural heterogeneity, spectral similarity, and data scarcity complicate classification. This study develops a machine learning-based framework implemented in Google Earth Engine to map dominant tree species in the Elnour Natural Forest Reserve (ENFR), Blue Nile, Sudan, using multi-temporal and multi-sensor remote sensing data. Multi-temporal Landsat 5 TM, Landsat 8 OLI, and Sentinel-2 MSI imagery were integrated with vegetation index (NDVI), topographic variables derived from a digital elevation model (DEM), and field observations. The performance of Random Forest (RF), Support Vector Machine (SVM), Classification and Regression Trees (CART), and an unweighted ensemble approach was evaluated across four reference years (2008, 2013, 2018, and 2021). Results show that RF and SVM consistently achieved high classification performance, with overall accuracy (OA) ranging from 85.0% to 92.0% and Kappa coefficients (κ) from 0.81 to 0.89, while maintaining stable and ecologically realistic species-area estimates. CART showed greater sensitivity to class imbalance and overestimated minor species (OA = 72.0–80.0%, κ = 0.65–0.74), whereas the ensemble approach amplified misclassification of rare classes (OA = 78.0–84.0%, κ = 0.70–0.78). The integration of Sentinel-2 data improved species discrimination due to enhanced spatial and spectral resolution, particularly in the red-edge region; however, algorithm selection remained the dominant factor controlling performance. Feature importance analysis identified near-infrared (NIR), shortwave infrared (SWIR), and NDVI variables as the most influential predictors. Multi-temporal analysis revealed declining class separability, reflected by decreasing MCC values, and a shift in species composition, including a decline in Acacia seyal (Delile) and an increase in Sterculia setigera Delile. These patterns indicate increasing ecological complexity driven primarily by anthropogenic pressures, with climatic variability acting as an additional stressor. Full article

Bone formation requires a substantial energy supply to sustain extracellular matrix production and mineralization, yet the temporal contribution of lipid metabolism during osteoblast maturation remains incompletely characterized. This study investigated the molecular and transcriptional remodeling of lipid metabolism. Intracellular lipid distribution was analyzed by confocal microscopy using Nile Red staining. Transcriptional modulation of lipid synthesis, storage, lipolysis, genes associated with mitochondrial fatty acid oxidation, and osteogenic markers were assessed by quantitative real-time PCR, and the biochemical composition was evaluated by Raman spectroscopy. Early stages of spheroid development showed higher expression of genes involved in lipid synthesis and storage (FASN, DGAT2, and PLIN2) together with intracellular lipid accumulation, whereas later stages displayed increased expression of lipolytic and β-oxidation markers (PNPLA2/ATGL, CPT1A, and HADHA), accompanied by the redistribution of lipid droplets. The Raman analysis revealed a time-dependent variation of lipid-associated CH₂/CH₃ bands and modulation of protein-related Amide I–III signals, consistent with biochemical remodeling during maturation. Overall, the data indicate a coordinated transcriptional shift from lipid accumulation-associated pathways toward lipid mobilization during osteogenic progression in a 3D culture. This model provides a controlled experimental platform for investigating metabolic regulation during bone formation and for studying metabolic alterations associated with skeletal disorders. Full article

Background: Despite significant improvements in blood safety, the risk of transfusion-transmitted infections persists, particularly from emerging and re-emerging viruses. For red blood cell (RBC) products, this risk is exacerbated by the fact that there is no routine testing for many of these pathogens, and effective, commercially available pathogen inactivation technologies specifically for RBCs are still lacking. This gap in the safety framework means that viruses capable of establishing an asymptomatic viremia—a characteristic of many arboviruses like Zika, dengue, and West Nile virus—present a tangible threat to the blood supply, highlighting the need for broad-spectrum countermeasures. Study Design and Methods: This study aims to investigate the antiviral activity of green tea extract (GTE) and its key catechins, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), against ZIKV in both cellular models and red blood cell (RBC) products. In vitro antiviral activity was assessed using A549 cells treated with GTE (150 μg/mL) or purified EGCG/ECG (20 μM). Mechanistic studies focused on viral attachment inhibition. Additionally, ZIKV-spiked RBC products were co-incubated with GTE (300 μg/mL) for 1 h to evaluate virucidal effects. Erythrocyte integrity was confirmed via hemolysis assays. Results: Co-treatment with GTE or catechins suppressed ZIKV replication by ≥3.64 logs (p < 0.001) in A549 cells. GTE and catechins primarily inhibited viral attachment. In RBCs, GTE reduced viral infectivity by 99.99% (4-log reduction) without compromising erythrocyte membrane integrity or cellular viability. Furthermore, RBCs with added GTE demonstrated a lower hemolysis rate during storage for up to 60 days. Conclusions: GTE exhibits potent virucidal activity against ZIKV in blood matrices, highlighting its potential as a pathogen reduction agent to enhance transfusion safety. Further development of GTE-based additive solutions or technologies is warranted. Full article

Trace metals are persistent stressors in coastal ecosystems, yet most marine algal toxicity assessments still rely on freshwater model species and growth-based endpoints that provide limited mechanistic resolution. Here, we quantified the sensitivity of two ecologically contrasting marine diatoms—the benthic Cylindrotheca closterium and the planktonic Thalassiosira weissflogii—to ten environmentally relevant metals using a dual-endpoint approach that integrates chlorophyll fluorescence (photosystem function) and Nile Red-based lipid-body fluorescence (metabolic reallocation). Fluorescence-based EC₁₀ values revealed distinct species- and metal-specific patterns, with C. closterium consistently responding at lower concentrations and Hg producing the strongest inhibition in both species (EC₁₀ ≈ 0.04–0.06 mg L⁻¹). Lipid-body accumulation detected earlier metabolic disturbance for several metals, particularly Hg, As, Cr(VI), and Cd, and frequently occurred at concentrations where fluorescence remained minimally affected. These sequential thresholds indicate that pigment impairment and metabolic reallocation represent mechanistically distinct stages of the cellular stress response that differ among metals and between diatom guilds. Comparison with published toxicity data shows that the dual-endpoint sensitivities observed here fall within, or slightly above, the upper range of reported microalgal responses, underscoring the pronounced susceptibility of benthic diatoms to redox-active and thiol-reactive metals. The strong agreement between fluorescence-based EC values and traditional growth-derived benchmarks for key metals further supports fluorescence as an operationally efficient endpoint suitable for integration into emerging ISO marine algal bioassays. Overall, this study demonstrates that pairing a rapid functional marker with a mechanistically informative metabolic biomarker enables metal-specific toxicity fingerprinting and provides an ecologically grounded basis for incorporating benthic diatoms into coastal metal risk assessment frameworks. Full article

Greater Ethiopia in the late medieval period, a somewhat delicate federation in the Horn constituted by the Christian highland kingdom and bordering Muslim princedoms, was integrated by interregional links of great significance, in a balance of roles within a wide trade network. Yet the interlacing web of connections saw as many disconnections. Sources from the Christian side as well as the Muslim side with its associated parties continue to provide light on various regional dynamics involved and allow analysis of how interactions were influenced by external actors such as Mamluk Egypt, the Ottoman Empire, and Christian Mediterranean states drawn by the belief that Abyssinia was ruled by Prester John. The purpose of this study is to expound the factors that shaped dealings between the two religio-political parties in order to help build a comprehensive perspective of the entangled milieu. The authors argue that a variety of conditions prevented domination by a single group and forged acceptance of a practical reality as a modus operandi. While several sources and references in Western languages on the wide regional interactions are known, this study aims to present a transcultural view on the topic through untapped Arabic studies examining related primary Arabic sources. Recent archeological work is also taken into account. Some emphases and clarifications are offered to promote an understanding of the region’s circumstances, the timing and aims of key episodes, and foreign interventions. Full article