Search Results (419)

Atlantic salmon (Salmo salar) is an important dietary source of health-promoting long-chain polyunsaturated fatty acids (PUFAs). As rearing conditions significantly influence fillet quality, this study evaluated the effects of warm and cool rearing temperature and photoperiod regimes on salmon growth, lipid profiles, and antioxidant capacity. Atlantic salmon (210 days old) were reared for 92 days under low temperature (14 °C, 12 h light) or high temperature (21 °C, 24 h light) conditions to simulate relevant seasonal conditions, winter and summer respectively. At day 302, conditions were reversed to create low-to-high (L→H) and high-to-low (H→L) treatments, continuing until day 362. Growth parameters, muscle lipid content, fatty acid profile, and antioxidant activity were measured at 302 and 362 days. Lipid content and fatty acid profile were also measured based on fillet location and fish sex. High rearing temperatures accelerated weight gain and increased total and neutral lipid contents, but elevated saturated fatty acids (SFA) and decreased PUFAs in structural polar lipids. High temperatures also significantly increased antioxidant activity, indicating elevated oxidative stress. Conversely, low temperatures suppressed growth but preserved essential PUFAs and maintained oxidative stability. Following the temperature shift, the H→L group had enriched polar lipids with PUFAs and maintained oxidative stability. On the other hand, L→H group showed lower PUFAs accumulation in polar lipid and enhanced oxidative stress. Total lipid content was higher in the head region, followed by the middle and tail sections of the fillet. However, fatty acid composition remained largely uniform across all three sections of the fillet. There were no significant differences in total lipid content between fish sexes. In conclusion, production efficiency and nutritional quality can be optimized by initially rearing salmon at high temperatures to promote rapid growth, followed by low temperature finishing phase to increase essential PUFA content and maintain oxidative stability. Full article

Microbially induced desaturation and precipitation (MIDP) is a promising eco-friendly technique for liquefaction mitigation. However, existing studies have primarily focused on silica sands under element-scale cyclic loading, and the dynamic response of MIDP-treated marine sand under seismic excitation remains poorly understood. In this study, the denitrifying bacterium Pseudomonas stutzeri was used to generate nitrogen gas in situ within typical liquefiable marine sand from the Haikou Jiangdong New Area, producing treated specimens with degrees of saturation ranging from approximately 99% to 80%. Shaking table tests were performed under Wenchuan earthquake motions with peak ground accelerations of 0.10–0.20 g. The results show that reducing the degree of saturation by approximately 18.9% decreases surface settlement by 77.6%, while the peak pore water pressure and lateral displacement are reduced by 21% and 15%, respectively. The acceleration response of the treated specimens also exhibits a notable attenuation effect. These findings provide preliminary comparative experimental evidence for the application of MIDP in the eco-friendly liquefaction mitigation of coastal marine sand foundations. Full article

The increasing occurrence of antibiotic residues in poultry meat represents a serious food safety concern associated with antimicrobial resistance and potential risks to human health. This study investigated the effects of electron beam irradiation on antibiotic residues and nutritional quality parameters of poultry meat. All experiments and data collection were carried out in 2025. Fresh poultry samples were irradiated using an ILU-10 pulsed linear electron accelerator at doses of 2, 4, 6, 8, and 10 kGy. Antibiotic residues were determined by HPLC-DAD, amino acid composition was analyzed using HPLC, and fatty acid profiles were evaluated by gas chromatography. Electron beam irradiation produced significant dose-dependent changes in the chemical composition of poultry meat. Total amino acid content decreased progressively with increasing irradiation dose, with reductions of up to 60–73% at 10 kGy depending on tissue type. Branched-chain and essential amino acids showed similar trends. Fatty acid analysis revealed a shift toward higher proportions of saturated fatty acids and a decline in monounsaturated and polyunsaturated fatty acids. The PUFA/SFA ratio decreased from 0.48 in control samples to 0.25 at 10 kGy. Tetracycline residues were not detected in any samples, whereas chloramphenicol residues were present in control meat but were progressively reduced after irradiation and became undetectable at doses ≥ 8 kGy. These results demonstrate that electron beam irradiation can effectively reduce antibiotic residues in poultry meat; however, higher irradiation doses may significantly alter amino acid and lipid composition. Therefore, optimization of irradiation parameters is necessary to balance improvements in food safety with the preservation of nutritional quality for the production of safe and sustainable food products. Optimization of irradiation parameters is therefore necessary to balance food safety benefits with preservation of nutritional quality. Furthermore, this research contributes to the achievement of Sustainable Development Goal (SDG) 2, while the obtained results also support SDG 3 by promoting safer food systems and protecting public health. Full article

This experiment investigated the effects of dietary Artemisia ordosica Krasch. (AOK) supplementation on the n3-polyunsaturated fatty acid (n3-PUFA) profile of subcutaneous adipose tissue (SADT) in Arbas cashmere goats and explored the underlying transcriptional mechanisms. Forty healthy, weaned kids (120 ± 10 days of age; similar body weight) were randomly allocated to two groups (n = 20): a control group (CON, basal diet) and an AOK group (AOK, basal diet with 3% of the roughage replaced by AOK). The feeding trial spanned 104 days, consisting of a 14-day adaptation period and 90 days of data acquisition. Compared with the CON group, AOK significantly reduced the content of saturated fatty acids (SFAs) and n6-polyunsaturated fatty acids (n6-PUFAs)/n3-PUFAs (n6/n3). In contrast, the levels of n3-PUFAs in the SADT of cashmere goats increased markedly (p < 0.05). Compared with the CON group, AOK exhibited significantly higher activities of hormone-sensitive lipase (HSL) (p = 0.027), adenylyl cyclase 2 (ADCY2) (p = 0.010), adenylyl cyclase 5 (ADCY5) (p = 0.046), cluster of differentiation 36 (CD36) (p = 0.013), solute carrier family 27 member 4 (SLC27A4) (p = 0.021), and fatty acid binding protein 4 (FABP4) (p = 0.040), along with significantly lower activities of fatty acid synthase (FAS) (p = 0.002), lipoprotein lipase (LPL) (p = 0.048), and stearoyl-coa desaturase (SCD) (p = 0.026) in SADT. Compared with the CON group, the activities of superoxide dismutase (SOD) (p = 0.032), catalase (CAT) (p = 0.010), glutathione peroxidase (GSH-PX) (p = 0.029), and total antioxidant capacity (T-AOC) (p = 0.002) were significantly increased in the AOK group. Transcriptomic profiling revealed that AOK supplementation downregulated mRNA levels of ADCY2, ADCY5, LPL, FAS, SCD, stearoyl-CoA desaturase 1 (SCD1), stearoyl-CoA desaturase 2 (SCD2), glycogen synthase 1 (GYS1), acyl-CoA oxidase 1 (ACOX1), acetyl-CoA carboxylase (ACC), diacylglycerol acyltransferase 1 (DGAT1), fatty acid desaturase 1 (FADS1), solute carrier family 27 member 2 (SLC27A2), erythroblastic leukemia viral oncogene homolog 4 (ERBB4), and carnitine palmitoyltransferase 1B (CPT1B) (p < 0.05). It also markedly induced acyl-CoA synthetase long-chain family member 4 (ACSL4) (p < 0.01) in SADT. Genes significantly enriched in the adenosine-monophosphate-activated protein kinase (AMPK) signaling pathway included LPL, SCD1, CPT1B, and GYS1 (p = 0.010). Genes significantly enriched in the phosphatidylinositol 3-kinase-akt (PI3K-Akt) signaling pathway included GYS1 and ERBB4 (p = 0.015). CPT1B, ADCY2, and GYS1 were identified as the genes significantly enriched in the insulin resistance signaling pathway (p = 0.048). LPL was the only gene significantly enriched in the cholesterol metabolism pathway (p = 0.049). Genes showing a tendency toward significant enrichment in the peroxisome-proliferator-activated receptor (PPAR) signaling pathway included ACSL4, CPT1B, SCD1, and LPL (p = 0.051). These interconnected cascades improve insulin sensitivity, stimulate triglyceride (TG) hydrolysis, and modulate n3-PUFA levels. Supplementation with AOK enhances n3-PUFA content by accelerating TG breakdown while simultaneously restraining FA oxidation in SADT. Consequently, AOK supplementation can be effectively used to enhance the nutritional value of cashmere goat meat through improved n3-PUFA deposition in SADT. Full article

The Tuzla Submarine Landslide represents one of the most significant mass-wasting features associated with the active North Anatolian Fault Zone (NAFZ). The failure surface geometry and sediment stratigraphy indicate the presence of a mechanically weak, saturated layer that may become unstable under strong seismic loading. This study presents a comprehensive geotechnical evaluation of the Tuzla Submarine Landslide. Based on regional sediment properties, the landslide was characterized and modeled with an estimated volume of 0.015 km³ and an average slope angle of 14°. The submarine landslide potential was investigated through re-analysis of seismic, geotechnical, and bathymetric datasets. Finite Element Method (FEM) simulations were conducted to model the seismic slope failure. Based on these analyses, the seismic slope displacements, stress distributions, and equivalent plastic strains were identified. The estimated landslide displacements under varying seismic acceleration scenarios corresponding to three major earthquakes ranged between 2.38 m and 4.12 m, depending on the triggering ground motion and slope stability conditions. These findings highlight that reactivation of the Tuzla submarine landslide, potentially triggered by a future large earthquake along the NAFZ, could pose a moderate landslide hazard to the coastal settlements bordering the Marmara Sea. Full article

The incorporation of natural plant extracts into dairy products has attracted increasing interest due to their potential to enhance nutritional value and product stability. This study evaluated the effects of distilled rose (Rosa damascena Mill.) flower ethanolic extract on the physicochemical, texture, microbiological, and sensory properties of kashkaval cheese. Cheese samples were immersed in solutions containing rose extract at concentrations of 1.25% (S2) and 2.5% (S3) and compared with a control (S1) during ripening. Sensory evaluation showed that S2 achieved the most favorable balance of aroma, flavor, and overall acceptability, whereas S3 exhibited reduced acceptance due to an excessively strong floral aroma. The enrichment did not significantly affect fat (26–29%), water (33–36%), or salt (~2%) content. However, rose extract accelerated proteolysis, with S2 showing the highest maturity index (NPN/TN 13.76% at month 6) compared with the control (11.19%). Enriched samples showed improved amino and organic acid profiles, while the control contained higher levels of saturated fatty acids and cholesterol. All samples met microbiological safety criteria. Rose extract also influenced color and texture properties. These results demonstrate that rose extract can serve as a functional ingredient to improve the quality and technological properties of kashkaval cheese, with optimal effects at 1.25%. Full article

Water saturation is a key factor influencing the mechanical behavior and stability of tunnel rock masses in water-bearing strata. However, current research based on physical model tests has yet to systematically reveal its intrinsic relationship with rock failure modes. To address this gap, this study systematically investigated the effects of water saturation levels (0%, 33%, 58%, and 100%) on the failure mechanisms of four typical tunnel cross-section models: wall-arch, horseshoe, circular, and square. The results indicate the following: (1) Water saturation exerts a significant deteriorating effect on the mechanical properties of tunnel models. As saturation increases, peak stresses generally decrease across all models, but the extent of deterioration varies markedly by tunnel shape: at low saturation (≤58%), peak stress follows the order Wall-Arch > Horseshoe > Circular > Square; at high saturation (>58%), this relationship reverses to Circular > Square > Wall-Arch > Horseshoe. (2) The failure mechanism is significantly controlled by saturation, exhibiting distinct transition characteristics: At low saturation, capillary effects dominate, with matrix suction enhancing material strength, resulting in brittle failure with crack concentration. At high saturation, pore water pressure effects prevail, reducing effective stress and leading to plastic failure dominated by distributed shear slip. Notably, square tunnels consistently exhibit pronounced flexural failure characteristics across all saturation levels. (3) Energy evolution analysis indicates the following: as saturation increases, the total energy U of specimens decreases, the dissipation rate of dissipated energy U_d accelerates, the energy inflection point advances, and failure precursors manifest earlier. The energy dissipation factor n of high-saturation specimens decreases more significantly with increasing strain, confirming that moisture accelerates energy dissipation and promotes premature material instability. (4) Significant differences exist in the response characteristics to moisture effects among tunnel types: Square tunnels consistently exhibit pronounced flexural failure; Circular tunnels demonstrate optimal stress distribution properties under high water content conditions; Wall-arch and horseshoe-shaped tunnels are most sensitive to saturation changes, with their failure modes transitioning from tensile-dominated to shear failure as water content increases. This study reveals the coupled mechanism between water saturation and tunnel cross-sectional shape in influencing rock mass stability. Full article

Enzyme-assisted carbon capture is attracting massive interest, and absorbents composed of aqueous carbonate supplemented with carbonic anhydrase have proven particularly promising. Here, we study basic capture mechanisms using a novel approach grounded in comparative enzymology. We determined initial, steady-state capture rates in potassium carbonate under a range of conditions and observed a characteristic saturation behavior at high concentrations of either enzyme or CO₂. These results could be rationalized by a modified Michaelis–Menten framework applied to a “reaction zone” near the liquid surface. Capture rates corresponded directly to enzyme reaction rates in the reaction zone as determined by K_M and k_cat, and this explained the observed saturation behavior. The kinetic data suggested a depth of the reaction zone of about 20 µm. This meant that equilibrium between CO₂ and HCO₃⁻ was obtained within this shallow film and that enzymes deeper in the liquid had little or no influence on capture rates. This approach also allowed us to rationalize the effect of pH on enzyme-assisted capture rates. Overall, steady-state kinetics can be used in comparative and mechanistic analyses of enzyme-accelerated carbon capture. The approach is theoretically simple, requires limited experimental input, and offers key molecular insights. Full article

This study investigates the seismic response of reinforced soil retaining walls through reduced-scale 1 g shaking table experiments, with particular emphasis on deformation behavior and pore water pressure generation in saturated sandy soils. Physical models were constructed using Firuzkuh silty sand and extensible fabric reinforcement, considering two soil conditions: an undisturbed loose state and a compacted state with a relative density of 35%. Horizontal dynamic loading with peak acceleration ranging from 1 g to 3 g was applied, while acceleration, displacement, and pore water pressure responses were continuously monitored. The results demonstrate a pronounced depth-dependent pore water pressure response, with deeper soil layers exhibiting higher magnitudes and longer persistence of excess pore pressures. In the undisturbed loose sand, the excess pore water pressure ratio approached unity at depth, indicating near-liquefaction conditions. In contrast, moderate densification significantly reduced pore pressure buildup and promoted partial dissipation during shaking. Reinforcement and compaction were found to effectively limit lateral displacement and settlement, leading to improved seismic performance. The findings highlight the critical roles of soil fabric, density, and reinforcement in controlling deformation and liquefaction susceptibility of reinforced soil retaining walls under seismic loading. Full article

Thermal stress is an important factor affecting the long-term performance of solid insulation in GIS/GIL, and the physicochemical properties of insulating materials play a crucial role in governing surface charge dynamics. This study investigates the influence of accelerated thermal aging on the surface charge behavior of Al₂O₃-doped epoxy resin insulators. Different aging severities were applied to simulate long-term service conditions, and charge accumulation and dissipation characteristics were correlated with physicochemical evolution revealed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicate that increasing aging severity reduces the charge accumulation rate while increasing the saturated surface charge density. Voltage polarity significantly influences surface charge behavior: a relatively uniform distribution is observed under positive polarity, whereas localized charge clusters are more likely to form under negative polarity. Thermal aging also accelerates the development of surface defects and increases polar functional groups, resulting in degraded insulating performance. These findings clarify the relationship between thermal aging, physicochemical evolution, and surface charge dynamics in epoxy-based insulation systems. Full article

Nutritionally crucial unsaturated fatty acids, especially rich in high omega-3 bonds, are very prone to oxidation. This phenomenon makes oxidation stability a substantial challenge in every formulation, especially those which contain or at some stage of preparation contain water. Bigels and emulgels, which represent promising structured lipid systems for replacing saturated and trans fats in food formulations, pose significant oxidative stability challenges. This review examines oxidation mechanisms in such biphasic systems. Oxidation in bigels and emulgels proceeds through both free-radical-mediated autoxidation and metal-ion-catalysed pathways, with the oil–water interface serving as the primary reaction zone where pro-oxidants concentrate, and lipid substrates become accessible. Structural configuration critically determines oxidative stability, following the sequence W/O bigel > bicontinuous bigel > O/W bigel. The high viscosity of gel matrices provides substantial protection by restricting radical mobility and oxygen diffusion. Mass transfer occurs via diffusion, collision–exchange–separation, and micelle-assisted mechanisms, with association colloids forming localized interfaces that accelerate oxidation. Thermal processing presents particular challenges, as temperatures above 50 °C disrupt most gel structures and accelerate oxidative degradation. Effective protective strategies include interfacial engineering with emulsifiers to reduce oil–water interfacial tension, incorporation of natural antioxidants (e.g., phenolic compounds and tocopherols), and synergistic antioxidant combinations. This review provides a mechanistic framework for formulating oxidatively stable bigels and emulgels suitable for food applications. Full article

Mineral scale deposition remains a major flow-assurance constraint in oil and gas operations, especially in water-flooding and produced-water reinjection, where mixing between incompatible brines promotes super-saturation and precipitation of poorly soluble salts. This work introduces a novel extension of traditional methods used for modeling chemical inhibition and the predictive evaluation of oilfield scale-inhibitor molecules. A systematically optimized Two-Dimensional Quantitative Structure–Activity Relationship Model based on the k-Nearest Neighbors algorithm 2D-QSAR-KNN model was developed to quantitatively link molecular constitution of phosphonate inhibitors, brine chemistry, and operating factors with inhibition efficiency IE %. The optimized model achieved strong accuracy and generalization R²_train = 0.9182, R²_test = 0.9306, and R²_global = 0.9208 with low prediction errors RMSE_train = 4.7888%, RMSE_test = 4.5485%, and RMSE_global = 4.7421%. Median absolute errors remained minimal for the train set = 0.80%, and test set = 1.63%, and model stability was confirmed by high correlation with experimental IE % r = 0.94 and R²_train/R²_test ≈ 0.99, showing no sign of overfitting. Additionally, an inverse-2D-QSAR framework was applied to identify the optimal molecular descriptor profile expected to maximize inhibitory performance within normalized bounds, providing rational rules for next-generation inhibitor design. The findings highlight the practical value of QSAR-inspired AI modeling to accelerate molecule screening and dosage exploration prior to laboratory validation, supporting more cost-effective, interpretable, and environmentally aware sulfate-scale inhibition strategies under high-salinity reservoir conditions. Full article

Compact carbonate stones are widely used in architectural heritage for their aesthetic value and cultural significance, yet their long-term durability in saline environments remains insufficiently understood, particularly when assessed using standard salt crystallization tests developed primarily for porous lithotypes. This study investigates salt-induced deterioration in Portoro limestone, a compact ornamental carbonate extensively employed in historic architecture, considering four commercial varieties representative of heritage applications. Salt crystallization tests were performed using saturated sodium sulphate (Na₂SO₄) and sodium chloride (NaCl) solutions following the relevant European standard procedure, with the protocol extended to 45 cycles to capture delayed deterioration processes. Both untreated specimens and samples subjected to controlled thermal pre-conditioning at 300 °C and 500 °C were tested to activate latent microstructural weaknesses. Material decay was assessed through mass variation, porosity changes, surface observations, Leeb rebound hardness and ultrasonic pulse velocity measurements. Results demonstrate that deterioration is primarily controlled by salt type and microstructural characteristics rather than by total porosity. Sodium sulphate induced severe internal damage and abrupt structural failure associated with mirabilite crystallization, often following a prolonged phase of apparent stability. In contrast, sodium chloride causes mainly superficial effects with negligible mechanical impact. Thermal pre-conditioning accelerated damage development, while non-destructive techniques revealed internal deterioration well before visible damage occurred. These findings indicate that standard crystallization tests may be inadequate for low-porosity stones and that extended-cycle approaches provide a more reliable framework for durability assessment in saline environments. Full article

This study systematically investigated the dynamic changes in fatty acid composition and oxidative stability of hickory nut oil during accelerated oxidation, and characterized the metabolic features associated with lipid oxidation using a metabolomics approach. Accelerated oxidation was conducted using the Schaal oven method. The results showed that the peroxide value (POV) and malondialdehyde (MDA) content reached maximum levels of 121.5 meq/kg and 1.94 μg/mL, while the conjugated diene value (CDV) and carbonyl value (COV) increased to 15.12 and 19.68 meq/kg, respectively. The fatty acid profile exhibited notable changes, with unsaturated fatty acids decreasing from 92.52% to 90.65% and saturated fatty acids increasing from 6.92% to 7.88%. A total of 2026 metabolites were identified, among which fatty acyls and benzenoids were predominant. The oxidation rate remained low during the initial phase (0–10 days) but increased markedly after approximately 25 days, leading to accelerated oxidation and a pronounced decline in oil quality. Pathway enrichment analysis further revealed that α-linolenic acid metabolism was the principal pathway associated with the oxidative process of hickory nut oil. Full article

This paper studies constrained model reference adaptive control (MRAC) for a planar unmanned ground vehicle (UGV) subject to actuator limits and safety requirements. First, we establish a double-integrator model by applying dynamic feedback linearization to a nonholonomic kinematic model with acceleration input, while simultaneously accounting for external disturbances. A constrained MRAC scheme is developed that enforces constraints at two levels: (i) actuator constraints are guaranteed by saturating the physical inputs after mapping the adaptive virtual control through the inverse kinematic transformation, and (ii) safety constraints are enforced via componentwise control barrier function (CBF) on the tracking error, which induces explicit bounds on the plant state. A projection-based adaptive law is introduced to keep parameter estimates bounded and to ensure well-posedness under saturation-induced mismatch. Moreover, we propose a sufficient feasibility condition that explicitly relates safety margins, disturbance bounds, and available actuator authority, thereby forming a guideline for feasible region design. Simulation studies demonstrate that the proposed method achieves constraint-satisfying tracking under bounded disturbances while respecting physical actuator constraints. Full article