Search Results (9,144)

Agricultural by-products are increasingly recognized as sustainable resources for mushroom cultivation and biomass valorization. This study evaluated pineapple stubble and coffee pulp as functional substrate supplements for Cordyceps militaris cultivation. Fruiting bodies were successfully produced on brown rice substrates supplemented with 5–15% pineapple stubble or coffee pulp, either alone or in combination. Substrate composition markedly influenced fungal morphology, biological efficiency (BE), and cordycepin production. Moderate supplementation improved cultivation performance, whereas excessive supplementation reduced BE. Cordycepin accumulation was generally higher in the substrate than in the fruiting bodies. The highest cordycepin content was observed in the substrate supplemented with 15% coffee pulp, reaching 3.93%, approximately twofold higher than that of the brown rice control. Correlation analysis revealed that carbon content and the carbon-to-nitrogen (C/N) ratio were positively associated with BE, while nitrogen content was positively correlated with cordycepin accumulation in the substrate. In addition, coffee pulp extract exhibited notable adenosine deaminase inhibitory activity, suggesting that substrate-derived bioactive compounds may contribute to enhanced cordycepin accumulation during cultivation. After cultivation, the spent mushroom substrate showed reduced C/N ratios and increased nitrogen content, indicating active fungal metabolism-mediated substrate transformation. These findings demonstrate that coffee and pineapple by-products can serve as sustainable supplements to improve cordycepin production in C. militaris. Furthermore, the resulting spent substrate, enriched in nitrogen and bioactive compounds, may represent a valuable secondary resource for agricultural and industrial applications. Full article

In recent years, a sharp increase in coal-based power generation has been observed in a number of countries. Coal-fired thermal power plants remain the main source of harmful emissions in the energy sector of many countries, including Kazakhstan. This creates a strong need for the development of effective methods to reduce pollutant emissions at thermal power plants. The aim of the present study is to perform a numerical investigation of the effectiveness of staged combustion technology with secondary air injection (Over-Fire Air, OFA) applied to three boilers—PK-39, BKZ-160, and BKZ-75—which differ in design, capacity, and furnace configuration. CFD modeling was carried out using the FLOREAN package, adapted to the conditions of the Kazakh energy sector, which relies on high-ash coal (more than 40%) for coal-based power generation. Model validation was performed against experimental data obtained from operating thermal power plants. It was found that air injection through OFA injectors intensifies turbulent mixing, reduces peak temperatures in the main combustion zone, and ensures a more uniform distribution of heat release along the furnace height, thereby suppressing thermal NOx formation. It is shown that the spatial structure of NO concentration fields at the furnace outlet strongly depends on the design features of each boiler. The results demonstrate the high efficiency of staged combustion technology in reducing nitrogen oxide emissions and improving the environmental performance of pulverized-coal boiler units. The obtained results can be used in the design of new and the modernization of existing thermal power plants utilizing coal-based power generation. Full article

Effective thoracic surgery requires timely, predictable operative lung collapse. During one-lung ventilation (OLV), lung collapse is not merely a mechanical consequence of nonventilated lumen opening but a phase-dependent physiological process. Rapid phase I collapse is driven by elastic recoil and passive gas venting, whereas slower phase II collapse depends on residual alveolar gas absorption. Communication between the operative-side airway and the atmosphere before pleural opening may permit tidal gas movement, ambient air entrainment, and nitrogen re-entry during the closed-chest period, delaying subsequent absorption collapse. This narrative review reorganizes lung collapse strategies, including denitrogenation, operative-side airway occlusion, preemptive OLV, disconnection, bronchial suction, and the open-clamp airway technique, according to timing and physiological target. Before pleural opening, alveolar nitrogen should be reduced and ambient air entrainment prevented. Around the pleural opening, airway patency and brief suspension of positive-pressure ventilation may preserve elastic recoil venting. During OLV maintenance, re-clamping or limiting atmospheric communication may support residual gas absorption. This phase-based framework interprets recent clinical findings as interventions acting before, during, and after pleural opening. This may help clinicians select strategies according to the lung isolation device, oxygenation reserve, and surgical environment, although standardized endpoints and component-level validation remain necessary. Full article

Street-level concentrations of nitrogen dioxide (NO₂) and fine particulate matter (PM_2.5) pose serious public health risks in European cities, yet accurate multi-year prediction at traffic-dominated sites remains challenging. This study applies XGBoost (XGB) and Random Forest (RF) to predict hourly NO₂ and daily PM_2.5 at two street monitoring sites in Copenhagen, Denmark, trained on 17 years of observational data and evaluated on two independent years. Three-dimensional variational assimilation (3D-Var) and the Extended Kalman Filter (EKF) are then applied as post-processing corrections to the ML predictions using co-located observations. XGB achieved RMSE values of 9.5 and 7.4 µg/m³ for HCAB and JGTV NO₂, respectively, in the 2018 test year. Both DA methods improved substantially on the ML baseline, with 3D-Var reducing NO₂ RMSE by up to 57% and spike event RMSE by up to 51%. EKF achieved near-complete elimination of systematic bias across all configurations. The framework is computationally lightweight and can be applied to any deterministic model prediction at a monitoring station, including outputs from physics- and chemistry-based dispersion models. Overall, the findings show a practical way to improve street-level air quality prediction, with direct relevance for operational forecasting and public health protection. Full article

Background and Objectives: This study aims to evaluate easily accessible clinical and laboratory parameters in older adults presenting with nontraumatic abdominal pain and to explore factors associated with significant findings on abdominal computed tomography (CT). The goal is to help prevent diagnostic delays and reduce emergency department (ED) length of stay by minimizing unnecessary testing. Materials and Methods: This retrospective cohort study evaluated patients aged 65 years and older presenting to a high-volume tertiary ED with acute nontraumatic abdominal pain who underwent abdominal CT between January 2020 and January 2022. To maintain data integrity in a crowded ED environment, only patients with complete medical documentation were enrolled. Based on objective radiological outcomes from official reports, patients were categorized into two groups: those with Acute Pathological CT Findings (acute intra-abdominal pathology explaining the presentation) and those with Non-Acute/Negative CT Findings (normal scans, chronic, incidental, or extra-abdominal findings). Multivariable logistic regression was performed to identify independent predictors of acute pathological findings. Results: A total of 503 patients were included, of whom 178 (35.3%) had Acute Pathological CT Findings. Univariable analyses showed that elevated Alanine Aminotransferase (ALT), total bilirubin, and Gamma-Glutamyl Transferase (GGT) were significantly associated with acute pathological findings, whereas higher levels of Blood Urea Nitrogen (BUN), creatinine, and troponin were more prevalent in the Non-Acute/Negative CT Findings group. Conclusions: Despite the identified associations, a reliable predictive model could not be established; therefore, CT is considered to remain a fundamental tool for accurate diagnosis in older adults. Full article

The valorization of vegetable-oil biomass into bio-based functional fluids offers a sustainable route for replacing petroleum-derived insulating liquids in power equipment. In this study, soybean and canola oils were used as renewable lipid feedstocks and converted into biomass-derived ester fluids through acid-catalyzed transesterification with methanol, ethanol, 1-propanol, and 1-butanol. The obtained ester-rich products were subjected to a combined physicochemical, dielectric, and thermal screening workflow, including kinematic viscosity at 40 °C (ν₄₀), acid value, breakdown voltage (BDV), differential scanning calorimetry (DSC; 2–8 °C min⁻¹ under N₂), and oxygen bomb calorimetry. Transesterification effectively upgraded the vegetable oils into low-viscosity ester-rich product fluids for most alcohol routes, with soybean methyl ester (SME) reaching 4.41 ± 0.02 mm² s⁻¹ and selected canola-derived esters showing viscosities of 5.81–6.81 mm² s⁻¹. However, the functional performance of the biomass-derived fluids was strongly governed by the alcohol route. SME exhibited the most favorable balance between dielectric and physicochemical properties, delivering the highest BDV of 64.90 ± 9.74 kV, exceeding the IEC 60156 threshold of 30 kV, while maintaining a low acid value of 0.0103 ± 0.0006 mg KOH g⁻¹. In contrast, propyl- and butyl-derived esters showed substantially lower BDV values of ≤14.98 kV, whereas ethanol-derived products retained near-neat-oil viscosities and were unsuitable for BDV testing under the applied conditions. Although propyl- and butyl-derived ester-rich products reduced kinematic viscosity, their markedly lower BDV values were likely associated with route-dependent product heterogeneity, lower alcohol–oil miscibility, possible residual polar impurities, and moisture sensitivity; therefore, they were regarded as non-optimized screening outcomes rather than IEC-compliant transformer-fluid candidates. DSC analysis provided comparative thermal-response descriptors under nitrogen, with methylation producing more coherent endothermic features. The combustion heats of the ester-rich products were concentrated at approximately 39–41 MJ kg⁻¹, lower than that of the mineral-oil reference in this dataset, suggesting combustion heat was used only as a preliminary energy-density descriptor and was not interpreted as direct evidence of improved fire safety. From an engineering-safety perspective, the lower combustion heat of the bio-esters may reduce the potential fire-load contribution during fault-related fire scenarios, although full fire-safety qualification requires additional flash-point, fire-point, and aging evaluations. Overall, this work demonstrates that alcohol route selection is a critical factor in converting vegetable oil biomass into high-value bio-based insulating fluids. Among the tested formulations, soybean methyl ester is the most promising baseline candidate for further development as a biodegradable, sustainable transformer fluid. Full article

Nitrogen fertilization plays a central role in the intensification and sustainability of tropical pasture systems by influencing forage production, animal performance, and greenhouse gas (GHG) emissions. Although the individual components of these systems have been extensively studied, studies that simultaneously integrate soil nitrogen processes, forage responses, animal performance, and environmental outcomes within a unified framework remain scarce in the literature. This structured narrative review aimed to synthesize current knowledge on the role of nitrogen in tropical pastures, addressing soil–plant–animal–environment interactions with a focus on nitrogen use efficiency, productivity, and GHG emissions. Studies were selected from Google Scholar using keywords related to nitrogen fertilization, tropical forages, GHG emissions, and animal performance, prioritizing research conducted with C4 forage species. The reviewed evidence demonstrates that nitrogen fertilization consistently increases forage accumulation, tillering, crude protein concentration, stocking rate, and animal productivity per unit area; however, nitrogen recovery efficiency decreases at high application rates. The timing of nitrogen application, dose splitting, and the choice of nitrogen source are key management strategies to reduce N losses through volatilization, leaching, and gaseous emissions, improving nitrogen use efficiency in tropical pasture systems. Future studies should focus on providing integrated answers that simultaneously consider soil, plant, animal, and environmental components, in order to support more efficient and sustainable nitrogen management in tropical livestock systems. Full article

Anti-nutritional factors (ANFs) in terrestrial plant feeds constrain efficient herbivore production, an issue intensified by rising feed costs and growing demand for animal products. Unlike previous reviews that focus on single ANFs or feed types, this review provides an integrated, cross-species framework linking ANF chemistry, rumen microbial interactions, and mitigation strategies. It examines major ANF classes—tannins, phytates, saponins, oxalates, protease inhibitors, lectins, glucosinolates, and gossypol—and their distribution and biochemical modes of action. Mechanistic pathways are grouped into digestive effects (reduced palatability and enzyme inhibition), microbial effects (altered rumen microbiota and fermentation), metabolic effects (impaired absorption), and mineral interactions (nutrient complexation and chelation). Species-specific responses are evaluated, emphasizing the partial detoxification capacity of the rumen microbiome and the dose-dependent nature of ANF effects. Mitigation strategies—physical, chemical, microbial, enzymatic, probiotic, and genetic—are critically assessed for efficacy, scalability, and sustainability. Emerging metabolomic and metagenomic evidence shows that certain ANFs confer functional benefits at controlled doses; for example, tannins improve nitrogen retention, saponins reduce methane, and phytic acid scavenges free radicals. This synthesis supports strategic management rather than complete elimination, informing safe and sustainable use of terrestrial feeds under evolving food-security and environmental challenges. Full article

Reduced-oxide titanium (Ti) protective coatings were fabricated on 316L stainless-steel substrates to improve the corrosion resistance of low-cost metallic components for proton exchange membrane water electrolysis (PEMWE). A low-temperature atmospheric plasma spraying process assisted by a self-designed extended protective nozzle was employed to suppress the oxidation of Ti particles during deposition. The nozzle provided auxiliary argon shielding and reduced the thermal exposure of in-flight particles, thereby limiting their interaction with ambient air. The deposited coatings exhibited a continuous lamellar structure with average thicknesses of approximately 78–98 μm. Phase and elemental analyses indicated that α-Ti(O) was the dominant phase, with limited oxide formation in the coating. ONH analysis further showed that the oxygen and nitrogen contents of the coatings were 0.95–1.69 wt.% and 0.049–0.087 wt.%, respectively. During the 6 h potentiostatic test, all Ti-coated samples showed lower and more stable current densities than bare stainless steel, with the 500 A 55 V coating maintaining the lowest final current density of approximately 0.4–0.5 mA/cm². These results demonstrate that low-temperature atmospheric plasma spraying is a feasible and cost-effective approach for preparing reduced-oxide Ti coatings for PEMWE components. Full article

Grassland foliar functional traits are closely linked to ecosystem functioning, biodiversity, and plant responses to environmental change. Hyperspectral remote sensing provides an efficient and non-destructive approach for mapping foliar traits, yet direct comparisons between UAV-based and airborne imaging spectroscopy remain limited. In this study, we evaluated the performance of UAV-based Nano and airborne Hyspex hyperspectral imagery for predicting ten foliar functional traits across experimental grassland plots at the Cedar Creek Ecosystem Science Reserve, USA. We further assessed the contributions of visible-to-near-infrared (VNIR) and shortwave infrared (SWIR) spectral regions, as well as the effects of spectral preprocessing approaches for minimizing confounding effects from canopy structure, illumination/viewing geometry, and soil background. Random Forest regression models were developed using plot-level average spectra derived from Nano and Hyspex imagery. Both UAV- and airborne-based imaging spectroscopy achieved moderate to high prediction accuracies for most foliar traits. High accuracies were obtained for non-structural carbohydrates (NSC), carotenoids, β-carotene, hemicellulose, and cellulose (R² = 0.66–0.82; NRMSE = 6–10%), while moderate accuracies were achieved for nitrogen, chlorophyll, and xanthophylls (R² = 0.51–0.74; NRMSE = 8–12%). In contrast, carbon and lignin consistently exhibited lower predictive performance (R² = 0.32–0.59; NRMSE = 9–15%). Despite covering only the VNIR spectral range, the UAV-based Nano imagery achieved accuracies comparable to those obtained using the airborne full-spectrum Hyspex imagery, indicating that high spatial resolution can partially compensate for limited spectral coverage by reducing soil background effects. The VNIR spectral region alone provided trait estimation accuracies comparable to those obtained using the full visible-to-shortwave infrared (VSWIR) spectrum, whereas SWIR wavelengths contributed only marginal improvements for a subset of structural traits. Among preprocessing approaches, vector normalization generally improved prediction performance by reducing the confounding effects of canopy structure and illumination/viewing geometry, whereas NIR_v-adjusted spectra provided limited benefits. Our findings demonstrate that UAV-based VNIR imaging spectroscopy can provide accurate and cost-effective estimation of grassland foliar functional traits. The results also highlight important trade-offs between spectral and spatial resolution in hyperspectral remote sensing and provide practical guidance for selecting imaging spectroscopy platforms and preprocessing approaches for grassland ecosystem monitoring. Full article

Understanding responses of soil organic carbon (SOC) fractions to variable hydrological conditions is essential to clarify carbon stabilization in subtropical lake wetlands. This study examined vertical and spatial variations of particulate organic carbon (POC), mineral-associated organic carbon (MAOC) and nutrient stoichiometry across four sites in Dongting Lake (0–200 cm depth, five layers). SOC and total nitrogen (TN) showed significant decreasing trends with depth from the surface to 60 cm (p < 0.05), with the highest values in the 0–40 cm layer and significantly lower values below 60 cm. In contrast, total phosphorus (TP) was vertically stable but differed greatly among sites. C/N, C/P and N/P ratios showed distinct regional disparities (p < 0.05). The proportions of POC/SOC and MAOC/SOC exhibited highly significant regional differences (p < 0.05) but no significant vertical variation or interaction effects (p > 0.05). The POC/MAOC ratio exceeded 1 only at Tuanzhou (1.62–2.20), indicating a vulnerable POC-dominated pool; other sites were MAOC-dominated (ratio < 1). Site-specific nutrient regulation further differentiated carbon pool characteristics: nutrients dominated carbon fraction variation at Tuanzhou and Huanghua, co-functioned with soil texture at Junshan, and reduced carbon stability under nutrient enrichment at West Dongting Lake. The texture control effect intensified with soil depth, and deep soil exhibited the strongest mineral protection capacity. We conclude that relative proportions of POC and MAOC in total SOC are region-specific, while their absolute concentrations decrease with depth. We recommend that wetland restoration prioritizes maintaining natural hydrological regimes and soil texture integrity, with future validation across multiple floodplain wetlands. Full article

Animal-based biomass is gaining increasing attention in composites technology as a sustainable alternative to conventional fillers, offering a green pathway in the generation of composites exhibiting improved performance via waste valorization. In the present study, carbonized sheep wool was incorporated into high-density polyethylene (HDPE) in various weight ratios up to 10% wt. to fabricate composite specimens. The resulting composites were evaluated through Dynamic Mechanical Analysis (DMA), while their morphology and chemical structure were investigated by Scanning Electron Microscopy (SEM) combined with Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. FTIR analysis revealed the presence of residual keratin-derived oxygen- and nitrogen-containing functional groups, indicating the retention of chemically active surface functionalities upon low-temperature carbonization. This evidence is further corroborated through qualitative (SEM-EDS) elemental mapping of the pristine surfaces of sheep wool fibers and the pyrolyzed biochar product. DMA experimental data demonstrated that sheep wool-derived biochar (SWB) can effectively reinforce HDPE, resulting in stiffness enhancement while reducing viscous dissipation, thereby highlighting its potential as a sustainable, eco-friendly filler and a viable pathway for circular valorization of animal biomass waste. Full article

This review evaluates the current state of knowledge on the use of wood fibres and related woody materials as partial substitutes for peat in substrates used for forest nursery production, with particular emphasis on container seedlings. The review was prepared as a structured narrative synthesis of the available literature, focusing on substrate composition, physical and chemical properties, tree seedling growth, root development, water regime, fertilisation, operational handling, economic aspects and remaining research needs. The available evidence shows that wood fibres are technically promising components of peat-reduced growing media, but their performance depends strongly on the raw-material origin, processing method, substrate proportion, tree species, and cultivation management. The most reliable results have been obtained with partial substitution systems, whereas peat-free solutions remain species-specific and require careful optimisation of irrigation, nitrogen supply, pH control, and substrate quality. Although wood-based materials may improve resource efficiency and, under favourable local conditions, reduce substrate costs, wider implementation is constrained by variable material quality, limited standardisation and insufficient operational-scale validation. The main remaining research need is to define species-specific application thresholds and management protocols and to link nursery performance with outplanting success and full production economics under commercial conditions. Full article

Microalgae represent a promising alternative as biofertilizers and biostimulants, providing essential nutrients and bioactive compounds that support plant growth. In this study, a screening of seven microalgal species—including Arthrospira platensis, Nannochloris sp., Chlorella sp., Chlorella vulgaris, Acutodesmus obliquus, Parachlorella kessleri, Coelastrella vacuolata—and one isolated mixed culture was conducted to evaluate their potential as biostimulants and biofertilizers under autotrophic cultivation conditions. Whole cultures and corresponding supernatants were directly applied, without any pretreatment, reducing potential processing costs. Their biostimulant activity was evaluated through multiple bioassays, including germination index and auxin- and cytokinin-like responses, while nitrogen, phosphorus, and potassium content was analyzed to assess biofertilizer potential. The results revealed that biostimulant effects were strongly influenced by species, concentration, and sample fraction. Chlorella species consistently showed high performance across assays, combining strong germination and rooting responses with high nitrogen content (8.2–8.8% w/w), while A. platensis and Nannochloris sp. showed inhibitory effects in many cases. Overall, under the cultivation and application conditions tested, C. vulgaris, mixed culture, and A. obliquus are identified as promising candidates for combined biostimulant and biofertilizer applications. This study is a primary step in identifying the most promising species as an alternative to synthetic fertilizers, enabling further optimization towards more sustainable agricultural practices. Full article

Maternal undernutrition in late gestation can compromise fetal development and postnatal productivity in beef cattle. This study evaluated whether maternal supplementation with hydroxytyrosol (HT)—a potent antioxidant from olive by-products—during late gestation could alleviate the effects of undernutrition on growth, concentrate conversion ratio, and metabolic and endocrine adaptation of male offspring during the fattening phase. Forty-six multiparous pregnant cows were assigned to four dietary treatments combining nutritional level (T100% vs. T60% of nutritional requirements) and HT supplementation (CONTROL vs. HT at 180 mg/kg of diet) exclusively during the last third of pregnancy. Maternal undernutrition reduced calf morphometric development at the beginning of fattening (4 months), although compensatory growth enabled recovery by slaughter (12 months). For live weight (LW), the feeding level and HT interaction showed a tendency (p = 0.084), but pairwise comparisons within the restricted groups suggested that calves from HT-supplemented dams were 31 kg heavier at slaughter than calves from non-supplemented dams (p = 0.023). HT supplementation was also associated with higher plasma urea concentrations at 12 months in restricted calves, suggesting potential adaptations in nitrogen metabolism without changes in glucose or IGF-1 profiles. In summary, these findings might support our hypothesis suggesting potential benefits in the development of male offspring from HT-supplemented cows during the last third of gestation. However, further studies will be needed to demonstrate definitive overall evidence of HT benefits. Full article