Search Results (3,739)

Widespread environmental contamination by per- and poly-fluoroalkyl substances (PFAS) has driven the phaseout of traditional long-chain compounds; however, the toxicity of their highly mobile, short-chain replacements to aquatic microorganisms remains less well characterized. This study compared the toxicity of perfluoroalkyl carboxylic acid (PFCA): long-chain perfluorooctanoic acid (PFOA, C8) and the short-chain perfluorobutanoic acid (PFBA, C4) in two structurally distinct microalgae, Prymnesium parvum and Chlorella sorokiniana. P. parvum was more sensitive to PFAS exposure than C. sorokiniana, with significant growth inhibition occurring at 25–50 mg/L and complete mortality at 100 mg/L, whereas C. sorokiniana exhibited significant effects at concentrations ≥200 mg/L. PFBA exhibited greater toxicity than PFOA in both species, with IC₅₀ values of 25.81 and 64.30 mg/L, respectively, in P. parvum and 101.4 and 277.1 mg/L, respectively, in C. sorokiniana. PFBA induced reactive oxygen species (ROS) generation, lipid peroxidation, and significantly increased in cell volume and chlorophyll content in P. parvum, whereas C. sorokiniana exhibited oxidative responses primarily at higher concentrations and no significant changes in cell dimensions or chlorophyll content. The responses indicate that oxidative stress is an important component of PFCA toxicity and sensitivity differs substantially between microalgal species. The contrasting responses may be associated with differences in cellular structure and physiology, although the underlying mechanisms require further investigation. Overall, PFCA toxicity was both compound- and species-dependent, and the greater toxicity of PFBA under the tested conditions demonstrates that short-chain replacement PFCAs should not be assumed to have lower biological toxicity than their long-chain counterparts. Full article

This study developed an integrated process combining ultrasound-assisted enzymatic extraction (UAEE) with purification for the efficient recovery of bioactive flavonoids from Rhododendron anthopogonoides Maxim. (RA). Extraction conditions were optimized via Plackett–Burman screening followed by response surface methodology (RSM). Optimal conditions (enzyme dosage 30 mg/g, liquid-to-solid ratio 30:1 mL/g, 70% ethanol, 70 °C, ultrasonic power 490 W, extraction time 40 min) produced a total flavonoid yield of 13.56%. RSM established a reliable quadratic model (R² = 0.9800), with artificial neural network cross-validation further validating the robustness of the optimized parameters. Notably, UAEE substantially outperformed conventional ultrasound-assisted extraction. Purification using AB-8 resin raised flavonoid purity to 25.4 ± 0.48%. SEM and FT-IR analyses revealed effective cell wall disruption while maintaining flavonoid structural integrity. UPLC-Q-Orbitrap-HRMS identified 19 flavonoid compounds in the purified fraction. In vitro assays demonstrated that the purified flavonoids exhibited strong antioxidant activity, with IC₅₀ values of 28 µg/mL (DPPH), 38 µg/mL (ABTS⁺), and 43 µg/mL (•OH), corresponding to scavenging rates of 98.4%, 98.1%, and 94.2% at 200 µg/mL, respectively. Furthermore, the purified flavonoids dose-dependently inhibited the release of NO, TNF-α, and IL-6 in LPS-induced macrophages at non-cytotoxic concentrations. Full article

The jump height of overhead transmission lines after ice shedding is closely related to electrical clearance, and structural safety. For different conductor parameters, span lengths, horizontal stress, and icing conditions, transient finite-element analysis can provide detailed dynamic responses, but repeated simulations are not convenient for fast engineering assessment. In addition, a deterministic prediction model only gives a single jump-height value, and the reliability of this value is difficult to judge when the input condition is close to the boundary of the sampled range. In this study, a Dimensionless-Group-Guided Bayesian Neural Network (DG-BNN) is developed to predict the ice-shedding jump height and estimate the associated uncertainty. The original physical variables are first transformed into seven dimensionless Pi-groups according to Buckingham Pi dimensional analysis. These variables describe the main effects of geometry, mass distribution, stress state, and ice shedding in a compact form. The network is trained through a two-stage procedure. A heteroscedastic regression model is first obtained with a trend-regularization term based on a fixed second-order polynomial, and then the deterministic layers are converted into Bayesian layers for probabilistic inference. Monte Carlo sampling is used to calculate the predictive mean, epistemic uncertainty, and aleatoric uncertainty. Temperature scaling is further introduced to adjust the prediction intervals on the validation set. The comparison with several regression models shows that DG-BNN can maintain accurate jump-height prediction while giving calibrated uncertainty information. On the FEM-generated test set, DG-BNN achieved an R² of 0.986, an RMSE of 0.958 m, and an MAE of 0.649 m. After temperature calibration, the coverage probability of the 90% prediction interval reached 89.96%. The model can therefore serve as a fast surrogate tool for ice-shedding response assessment, especially when the reliability of the predicted result needs to be considered. Full article

Background/Objectives: Metal-based coordination compounds are attracting attention in medicinal inorganic chemistry because changes in the metal centre can influence their physicochemical properties and biological responses. This study aimed to evaluate two isostructural ammonium-M(II) hydrogenophosphite hydrates, (NH₄)₂[Mg(H₂O)₆]₃(HPO₃)₄ (complex 1) and (NH₄)₂[Co(H₂O)₆]₃(HPO₃)₄ (complex 2), as bioactive systems with potential anticancer and anti-inflammatory properties. Methods: The complexes were synthesized and characterized by X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), density functional theory (DFT) calculations, and Hirshfeld surface analysis. Their cytotoxic activity was evaluated against B16-F10, HT29, HepG2, and HL-60 tumour cell lines. For complex 2, apoptosis, cell-cycle distribution, and mitochondrial membrane potential were analysed by flow cytometry. Nitric oxide production was measured in LPS-stimulated RAW 264.7 macrophages. Results: Complex 2 showed the highest cytotoxic activity, particularly against HL-60 leukaemia cells (IC₅₀ = 36.98 μg/mL), whereas complex 1 displayed weaker activity. Complex 2 increased apoptotic cell populations, altered cell-cycle distribution, and induced mitochondrial membrane depolarization in HL-60 cells. Both complexes reduced nitric oxide production, with complex 2 showing the strongest effect (IC₅₀ NO = 22.46 μg/mL), exceeding that of diclofenac under the experimental conditions, while complex 1 showed comparable activity to the reference drug. DFT descriptors indicated higher electronic reactivity for complex 2. Conclusions: Replacement of Mg(II) by Co(II) enhances the biological activity of this hydrogenophosphite framework. Complex 2 combines cytotoxic activity against HL-60 cells with apoptosis-associated mitochondrial dysfunction and NO-inhibitory activity in activated macrophages, supporting hydrogenophosphite-based metal complexes as bioactive coordination compounds with potential as multifunctional agents. Full article

The utilisation of microwave radiances is crucial for enhancing the precision of weather forecasts. Despite existing uncertainties over land and ice-covered surfaces, recent advances have enhanced their use. This study examines the impact of assuming either Lambertian or specular surface reflection on the simulation of brightness temperatures for surface-sensitive, clear-sky AMSU-A microwave radiances across land and snow-covered areas. It represents the preliminary work before running a full assimilation and forecast impact study. Using the high-resolution HARMONIE-AROME regional modelling system, experiments were conducted to retrieve and analyse the retrieved emissivity in different conditions/seasons. The emissivity was also used as input to the radiative transfer model to simulate brightness temperatures of surface-sensitive sounding channels. The results show that the Lambertian assumption produces higher variability in dynamic surface emissivity, while the specular approach yields smaller and more consistent deviations. During winter, specular reflection shows higher first-guess departures (e.g., observations minus simulations) for surface-sensitive sounding observations, whereas in summer it performs better over land surfaces. Over snow-covered regions, the use of the Lambertian reflection to simulate the brightness temperature gives smaller mean errors for AMSU-A channels 4 (52.8 GHz) and 5 (53.59 GHz). These findings encourage further investigation into implementing a parameter that accounts for the Lambertian component of surface reflection when simulating brightness temperature in high-resolution limited-area models. Additionally, these findings provide practical guidance for configuring complex Nordic surface regional models and for future Arctic Weather Satellite microwave radiance assimilation. Full article

Atmospheric icing is one of the most critical meteorological hazards for unmanned aerial vehicles (UAV), whose operation under adverse conditions—high latitudes, elevated altitudes, long-endurance missions without pilot intervention—particularly exposes them to ice accumulation on aerodynamic surfaces and propellers. Unlike manned aviation, where this phenomenon has been extensively studied and regulated, a significant knowledge gap exists in the UAV domain that limits the development of effective protection systems adapted to energy constraints. This article provides an integrative review—conducted with a systematic search strategy following PRISMA reporting guidelines—of atmospheric ice formation mechanisms, their specific effects on UAV propellers, and the two most promising mitigation approaches: electrothermal modelling for the optimisation of electric heating systems and the development of functional surface materials including superhydrophobic coatings (SHC); composites with conductive nanofillers (graphene, carbon nanotubes); and piezoelectric actuators. The analysis demonstrates that hybrid systems combining passive and active strategies managed by intelligent control represent the most viable solution for extending UAV operational envelopes under known icing conditions, with a projected reduction in anti-icing system energy consumption of at least 40% relative to conventional continuous heating. This estimate is based on the most conservative published evidence: pulsed electrothermal de-icing achieves 40–60% savings versus continuous anti-icingSHC-assisted hybrid heating reduces IPS power by more than 80% on static aerofoils; and rotary-wing pulsed systems reduce mean consumption by 60–75% relative to continuous operation. Key research gaps are identified, and a prioritised future research agenda is proposed to support the development of certifiable anti-icing systems for rotary-wing UAV platforms. Full article

To comply with stringent emission regulations, the deployment of hybridized powertrains is continuously expanding. However, architectures such as plug-in and parallel hybrids intrinsically reduce the overall runtime of the internal combustion engine (ICE). Because the battery state-of-charge (SOC) dictates intermittent engine activation, this operational strategy inevitably induces frequent cold-start events. This study investigates the thermal dynamics of commercial catalyst geometries (300–1200 cpsi, 2–8 mil) via 1D numerical simulations under real-world driving conditions. Without active heating, high-thermal-mass substrates unexpectedly outperform ultra-thin-wall variants by buffering against convective quenching during prolonged idling. However, integrating start–stop functionality halts cold exhaust flow, elevating mean temperatures and marginalizing geometric disparities. Evaluating electrically heated catalysts (EHCs) reveals that discrete preheating is highly inefficient due to rapid heat dissipation. Conversely, continuous closed-loop heating coupled with start–stop functionality sustains operational temperatures for over 90% of the cycle. Under continuous heating, substrate geometry ceases to dictate thermal performance; instead, it governs electrical efficiency. Low-thermal-mass monoliths minimize cumulative energy demand to 213 kJ (versus 277 kJ for high-mass variants), incurring a negligible CO₂ penalty. Consequently, future hybrid architectures must integrate lightweight EHCs to ensure sustainable emission control. Full article

Diamond-coated tools are suitable for CFRP machining because of their high hardness, sharp cutting edge, and good wear resistance. However, the anisotropic and heterogeneous nature of CFRP makes drilling-induced defects, such as burrs, tearing, fiber pull-out, and delamination, difficult to avoid, especially at the hole exit. In this study, an ice-supported drilling method was proposed for CFRP hole machining using diamond-coated drills. An ice layer was formed beneath the CFRP laminate to provide simultaneous low-temperature cooling and mechanical support during drilling. Comparative drilling experiments were conducted at spindle speeds of 400, 1200, and 2000 r/min. The results showed that the ice-supported drilling method markedly improved the hole surface quality and inner-wall integrity of CFRP laminates. Compared with conventional dry drilling, the drilling temperature was reduced by 22.03%, 10.70%, and 11.45% at 400, 1200, and 2000 r/min, respectively, while the hole-exit delamination factor decreased by 41.68%, 27.45%, and 57.04%, respectively. Moreover, after the same number of drilled holes, the diamond-coated drill used under ice-supported conditions exhibited less severe surface wear and cutting-edge blunting than that used under conventional dry conditions. The observed improvements were interpreted as being associated with the combined thermal-regulation and temporary mechanical-backing effects of the ice-supported condition. Full article

Outdoor Internet of Things (IoT) sensor nodes require battery systems for which their behaviour and implementation limits are characterized under low-temperature and variableload conditions. This study documents a LiFePO₄ battery-pack prototype integrating a BQ29729DSET protection IC and a configured MAX17055ETB+T fuel gauge and descriptively compares its discharge runtime with that of a reference pack with a similar nominal capacity, comprising three parallel Samsung ICR18650-26H cells. Tests were conducted at −30 °C, 8 °C, and 25 °C under nominal load settings of 50, 100, and 200 mA. At 8 °C and 25 °C, the two configurations showed similar runtimes and nominal-current-based calculated capacities. At −30 °C, the LiFePO₄ assembly ran for 89.1 versus 66.0 h at 50 mA and 44.7 versus 37.2 h at 100 mA. An analysis based on the typical MCP1700 dropout characteristic bounds the portions of these LiFePO₄ runtimes recorded below the assumed regulation threshold at approximately 1.1 h and 0.9 h, respectively; even subtracting those complete intervals leaves positive differences of 33.3% and 17.7% relative to the reference runtimes. Complete current logs were unavailable; therefore, capacity and energy are reported only as nominal-current estimates. In the ICR18650-26H reference pack at −30 °C, the calculated capacity increased anomalously from 3302 to 4087 mAh as the nominal setting increased from 50 to 200 mA. The ICR cutoff remained above the estimated regulator-dropout thresholds, so dropout does not explain the anomaly; temperature, conditioning, and run-order effects cannot be excluded. Protection trip points and fuel-gauge accuracy were not experimentally verified. Our contribution is therefore reproducible design documentation combined with preliminary low-temperature runtime evidence rather than validation of a fully monitored and protected battery pack. Full article

To explore the significant systematic deviations of FENSAP-ICE numerical simulations under supercooled large droplet (SLD) conditions, a ridge regression correction method that integrates numerical priors and domain-knowledge-aided features for ice shape geometric parameters is presented in this manuscript. The FENSAP-ICE predictions of eight geometric ice shape parameters are incorporated as numerical priors into the machine learning model, transforming the learning objective from “predicting from scratch” to “correcting systematic bias.” Six engineering auxiliary features are constructed based on SLD icing physics to provide physically meaningful adjustable dimensions for small-sample modeling. A two-stage model combining Logistic Regression classification and Ridge Regression is designed for zero-ice cases on the lower-surface icing limit. Evaluated via Leave-One-Out Cross-Validation on 29 sets of NACA0012 airfoil SLD icing wind tunnel experimental data, the improved system reduces the sMAPE of total ice area from 79.47% to 34.65%, lower-surface ice horn angle from 105.19% to 28.08%, upper-surface icing limit from 61.75% to 35.48%, and average ice thickness from 42.12% to 20.89%, all compared with FENSAP-ICE predictions. Ablation experiments further reveal that the introduction of the numerical prior alone reduces prediction error by approximately 10 percentage points, serving as the primary performance driver. The proposed method features low computational cost and strong physical consistency, providing a practical bias-correction framework for SLD ice shape prediction under small-sample conditions. Furthermore, to address the potential optimistic bias arising from small-sample cross-validation, nested cross-validation together with multiple linear baseline models are additionally employed to verify the robustness and relative competitiveness of the proposed correction method. Full article

Echinophora tenuifolia subsp. sibthorpiana is an aromatic and traditionally used plant whose phytochemical diversity and pharmacological potential remain incompletely characterized. This study aimed to integrate comprehensive chemical profiling with antioxidant, antimicrobial, and antiproliferative evaluations of an acidified methanolic extract prepared from its aerial parts. Phenolic constituents, volatile compounds, and fatty acids were characterized using LC–MS/MS, GC–MS, and GC–FID, respectively. Antioxidant capacity was assessed using DPPH and ABTS assays, antimicrobial effects were evaluated by disc diffusion and broth microdilution methods, and antiproliferative activity was investigated in six human cancer cell lines and non-cancerous BEAS-2B cells. Apoptosis induction and cell-cycle alterations were further examined by flow cytometry. The extract contained a high total phenolic content of 181.78 ± 5.03 mg GAE/g and exhibited substantial DPPH and ABTS radical scavenging activities of 333.65 ± 2.94 and 262.18 ± 6.80 mg TE/g, respectively. LC–MS/MS analysis identified rutin hydrate, quinic acid, chlorogenic acid, narcissin, and vicenin-2 as the predominant non-volatile constituents. The essential oil was dominated by methyl eugenol (51.10%) and Δ-3-carene (32.23%), whereas lauric acid (29.71%) was the major fatty acid. The extract also exhibited measurable antimicrobial activity and concentration-dependent cytotoxicity, with the greatest sensitivity observed in MCF-7 breast cancer cells (IC₅₀ = 32.96 ± 4.80 μg/mL), followed by A549 and MDA-MB-231 cells. However, the relatively close IC₅₀ values observed in cancer and non-cancerous BEAS-2B cells indicated limited cancer-cell selectivity under the tested conditions. Flow-cytometric analyses demonstrated marked apoptosis induction in MCF-7 cells, reaching 57.93 ± 1.80%, together with a cell-line-dependent accumulation in the G2/M phase. Collectively, these findings indicate that E. tenuifolia subsp. sibthorpiana is a chemically diverse source of plant-derived bioactive compounds with notable radical scavenging and measurable antimicrobial and cytotoxic effects. Further bioactivity-guided fractionation and mechanistic studies are required to identify the active constituents and clarify their pharmacological relevance and selectivity. Full article

The Scaly-sided Merganser (Mergus squamatus) is an endangered duck endemic to East Asia. It usually gathers in single-species flocks through winter. Existing field records focus almost entirely on southern winter flocks. No prior work has described lone individuals spending winter in northern China. We conducted standardized three-year winter surveys (2019–2022) across five isolated ice-free river patches along the Taizi River, Liaoning Province, northern China, to document habitat use and flocking behavior of one solitary male. Despite the availability of five discrete overwintering sites, the focal bird only occupied two patches characterized by dense riparian concealment and low human disturbance, avoiding open, highly disturbed sites. Resource Selection Function (RSF) modeling indicated habitat attributes (concealment and human disturbance) strongly predicted site use (AICc weight = 0.79), whereas the abundance of heterospecific flocking partners (Common Mergansers Mergus merganser) exerted negligible influence (AICc weight < 0.01). This solitary male associated only with Common Mergansers, the species with the closest phylogenetic relatedness (mitochondrial genetic distance = 0.04365), and never aggregated with other sympatric waterbirds. Model comparison confirmed phylogenetic relatedness outperformed dietary similarity as a predictor of heterospecific flocking (AICc weight = 0.76). Our three-year observations of this single individual demonstrate that, when conspecifics are absent and suitable winter habitat is limited, this male prioritized high-quality, low-disturbance ice-free patches over social aggregation opportunities, and selectively formed mixed flocks with its closest phylogenetic congener. This multi-year case study provides rare empirical baseline data for understanding winter behavioral trade-offs of endangered cavity-nesting waterfowl under severe frozen river conditions, though all conclusions herein apply only to this focal male and cannot be generalized to the entire species. Full article

Climate change is increasingly affecting freshwater ecosystems across Northern Europe, yet the responses of inland waters differ according to regional climatic and environmental conditions. Latvia, located within the boreo-nemoral transition zone, provides an important case for understanding these responses. This review synthesises published evidence on climate-driven changes in Latvian inland surface waters by integrating information on climatic trends, hydrological processes, hydrochemical responses and freshwater biota. The available evidence indicates that increasing air temperature, changing precipitation patterns and more frequent hydrological extremes have altered river discharge, ice regimes, water temperature and lake processes. These hydrological changes generate cascading effects on nutrient transport, dissolved organic matter and water quality, ultimately influencing primary production, community composition, species redistribution and fish communities. The review identifies hydrology as the principal mechanism linking climatic forcing with hydrochemical and biological responses. Although the overall direction of change is consistent with observations across Northern Europe, local catchment characteristics and multiple stressors modify ecosystem responses in Latvia. The synthesis also identifies major knowledge gaps regarding ecosystem-scale processes, ecological thresholds and long-term integrated monitoring. Addressing these gaps will improve understanding of climate-driven changes in Latvian inland waters and strengthen the scientific basis for adaptive freshwater management in Latvia and comparable northern European regions. Full article

HMGB-1 is an alarmin representative of DAMP playing a central role in immunogenic cell death (ICD), a necessary condition in the dialog established between dying tumor cells and the immune system during some anticancer therapies. Therefore, early screening for ICD inducers represents a major priority in drug development today. In this work, we investigated the effect elicited by the clinical-grade CIGB-300 peptide, which impairs Protein Kinase CK2-mediated phosphorylation and other CK2 signaling connected kinases. Here, HMGB-1 extracellular release was investigated in an 18-cell line panel from blood malignancies, uterine-cervical cancer and NSCLC treated with CIGB-300 at equipotent doses (IC₅₀) over 24 h. Interestingly, CIGB-300 treatment upregulated the HMGB-1 protein levels at the culture supernatant in most of the cell lines (p = 0.01) and fold-change increases ≥ 2 were associated with intrinsic cell line sensitivity towards CIGB-300’s cytotoxic effect. However, the HMGB-1 release by CIGB-300 was context-specific with clear induction on blood and uterine-cervical cancer cells and a diffused response pattern in NSCLC. Importantly, CIGB-300 treatment of blood cancer patients enrolled in a Phase I study induced plasma HMGB-1 alarmin in 4 out of 7 subject who received the entire treatment plan. Altogether, our data reveal for the first time that CIGB-300 treatment is able to induce extracellular HMGB-1 release in vitro and in vivo which could be indicative of ICD induction in some kinds of tumors; furthermore, the induction of extracellular HMGB-1 alarmin as a putative CIGB-300 response biomarker merits further investigation. Full article

Spring conditions may influence reproduction in the Gyrfalcon, Falco rusticolus, but their effects are difficult to separate from prey variation. We compared 66 nesting territories in 2024 and 69 in 2025 across natural tree nests, artificial nests mounted in trees, rock nests, and raven-built bridge nests on the Yamal Peninsula, Russia. Occupancy did not differ between years (35/66 vs. 40/69; Fisher’s exact test, p = 0.606). The proportion of occupied territories with a confirmed nesting attempt was higher in 2025 but not statistically significant (18/35 vs. 30/40; p = 0.053). Hatching success was higher in 2025 (7/15 vs. 26/29; p = 0.003), as was apparent nesting success among attempts with known outcomes (3/11 vs. 19/24; p = 0.007). Exact paired comparisons of permanent quadrats detected no interannual difference in ptarmigan pellet occurrence. The reproductive contrast coincided with earlier warming and snowmelt in 2025. Direct observations of eggs laid in snow or ice accumulated within raven-built bridge nests illustrated a nest-scale pathway to early failure. Although this two-year comparison documents an association between spring conditions and breeding performance rather than demonstrating causality, the results show why spring conditions, prey, and functional nest-site availability should be evaluated together in Gyrfalcon monitoring and conservation. Full article