Search Results (9,255)

In this work, a flexible and sustainable radar-absorbing material (RAM) based on porous carbon derived from raw Kraft black liquor was developed. The porous carbon filler was synthesized through a simple, eco-friendly one-pot polymerization route, thereby avoiding lignin extraction, purification, and chemical activation steps. Macroporosity was introduced by using poly(methyl methacrylate) microspheres as a hard template, yielding a lightweight carbon material with a foam-like morphology, low density, and high porosity. The carbon filler was incorporated into a silicone rubber matrix at different loadings (5–25 wt.%) to produce flexible composites. The structural, morphological, and textural properties of porous carbon were investigated by SEM, EDX, Raman spectroscopy, nitrogen adsorption, and mercury porosimetry. The electromagnetic properties of composites were measured in the X-band (8.2–12.4 GHz) using a vector network analyzer. The mechanical behavior was evaluated through Young’s modulus. The results show that increasing filler content enhances dielectric losses and attenuation capability. Among all composites, the sample containing 20 wt.% of porous carbon exhibited the best electromagnetic performance, achieving a reflection loss of −42.3 dB at 10.97 GHz with a thickness of 2.43 mm, corresponding to an absorption efficiency of 99.99%. This performance is attributed to a favorable combination of impedance matching and quarter-wavelength cancellation effects. The developed sustainable, lightweight, and flexible composites demonstrate potential as low-cost RAM for aerospace and electromagnetic interference mitigation applications. Full article

The enhancement of startup and performance in a Tetradesmus obliquus-polyurethane sponge biofilm system was investigated via the regulation of the phytohormone Indole-3-acetic acid (IAA). IAA supplementation at 1 and 5 mg/L increased biofilm biomass and chlorophyll a content, with the maximum biofilm biomass reaching 48.2 mg/g, and improved nutrient removal performance under shock-loading conditions, particularly for total nitrogen (TN) and total phosphorus (TP). IAA treatment was associated with EPS remodeling, including an increase in the protein/polysaccharide ratio to 0.68 and a 16% enrichment in tryptophan-like protein components. These EPS-related changes coincided with a decrease in the absolute zeta potential to −2.49 mV, which may be relevant to enhanced initial biofilm development. The corresponding EPS-related changes were characterized by three-dimensional excitation–emission matrix (3D-EEM) and Fourier transform infrared (FTIR) analyses using representative concentrations. Furthermore, the IAA-treated biofilm showed improved resilience under low, medium, and high loading conditions, with the most favorable TN removal reaching 87% at 1 mg/L IAA. These results suggest that IAA supplementation at 1 and 5 mg/L can promote microalgal biofilm start-up and improve nutrient-removal resilience under the tested conditions, with 5 mg/L showing the strongest response in biofilm growth and structural characterization. Full article

The integration of appropriate tillage practices with straw returning can effectively mitigate soil degradation in Northeast China. However, limited research has explored the impacts of different tillage practices combined with varying straw incorporation depths on the structure and diversity of soil microbial communities. In 2016, a field experiment was initiated using a two-factor split-plot design, featuring six treatments: two tillage depths of 10 cm (D10) and 30 cm (D30) combined with three straw management practices—straw mixing incorporation (SM), straw deep burial (SB), and straw removal (SR). Soil samples collected in 2019 were analyzed for multiple soil properties and microbial indices. Results indicated that both straw returning and tillage depth significantly influenced soil organic carbon (SOC), soil total nitrogen (STN), total phosphorus (TP), and total potassium (TK), with the D30 treatment combined with straw returning optimizing soil nutrient contents most effectively. Under straw returning, D10 significantly increased urease activity in the 0–10 cm soil layer, whereas D30 enhanced this enzyme activity in the 10–30 cm soil layer, while β-glucosidase activity was less responsive to tillage depth. For the D10 treatment with straw returning, acid phosphatase activity was markedly higher than that in the straw removal treatment, whereas N-acetyl-β-D-glucosaminidase activity exhibited the opposite trend. Straw-returning methods had no significant effects on the bacterial and fungal Chao1 indices, while the Shannon index was positively correlated with key soil properties. Redundancy analysis (RDA) of microbial community composition at the phylum level and soil environmental factors revealed that soil nutrients in the 0–10 cm soil layer were positively correlated with Actinobacteriota, Ascomycota, and Basidiomycota, whereas the explanatory power of soil nutrients for microbial community variation decreased in the 10–30 cm soil layer. Our results highlight that tillage depth and straw returning can regulate soil microbial community composition and enhance soil nutrient cycling, thereby providing a theoretical basis for optimizing the combined application mode of tillage and straw-returning practices in Northeast China. Full article

Cymbidium goeringii, an important orchid species, holds significant aesthetic and commercial potential in horticulture. However, stem rot caused by Fusarium oxysporum has emerged as a major biological constraint hindering industry development. In this study, we isolated five endophytic fungal strains from C. goeringii roots—namely, DG3 (Bjerkandera), DG4 (Cylindrocarpon), CLG3 (Talaromyces), CLG6 (Clonostachys), and Z3 (Trichoderma)—and assessed their inhibitory efficacy against stem rot and their potential to promote growth in C. goeringii. In vitro assays indicated that all five fungal strains had the ability to fix nitrogen and produce indole-3-acetic acid, as well as the capability to produce protease and exert broad-spectrum antimicrobial effects. The five endophytic fungal strains exhibited stem rot-resistant effects, among which strain Z3 showed the best inhibitory effect against stem rot, with a control efficacy reaching 68.89%. Treatment of C. goeringii seedlings with these endophytic fungal fermentation broths for 100 d significantly promoted growth compared to the control. The fresh weight increased by 10.53% to 88.16%, and root activity was enhanced by 50% to 162.5%. Additionally, the plant height and the longest leaf length increased by up to 23.68% and 47.50%, respectively, compared to the control. Additionally, the total chlorophyll content was up to 25.34% higher than that of the control group, and the soluble protein content was up to 39.54% higher. The MDA content was reduced by up to 40.23% compared to the control group. These endophytes also regulated the activity of defense-related enzymes in C. goeringii, including delaying the decline in the activities of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase. These results highlight the potential of these five endophytic fungi as effective agents for managing stem rot in C. goeringii. Full article

Land use practices are a key driver of soil nitrogen (N) dynamics, yet their influence on N accumulation within distinct soil organic matter (SOM) fractions remains insufficiently understood. This study aimed to elucidate the responses of N accrual in different SOM fractions to contrasting land uses. To achieve this purpose, soil samples were collected from seven representative land uses: forest, pasture, corn plantation, sugarcane plantation, cassava plantation, orchard, and abandoned land. Subsequently, soil samples were fractionated into free particulate SOM (fSOM), occluded light SOM (oSOM), weakly bound form SOM (wSOM), and strongly bound form SOM (sSOM) fractions, and N contents were quantified for each fraction. The results showed pronounced land use effects on both the magnitude and distribution of N among SOM fractions. The forest land use consistently promoted greater N accumulation in fSOM (0.15 g N kg⁻¹ soil), oSOM (0.14 g N kg⁻¹ soil), and wSOM fractions (0.29 g N kg⁻¹ soil), reflecting high organic inputs and low disturbance intensity. The pasture land use exhibited the highest N accumulation in the sSOM fraction (1.01 g N kg⁻¹ soil), indicating enhanced stabilization of N through strong organo-mineral associations. Intensively managed croplands and abandoned land generally displayed lower N storage across SOM fractions. Overall, these findings highlight the critical role of land use in regulating N partitioning and stabilization within SOM fractions and underscore the importance of low-disturbance, perennial vegetation systems for improving long-term soil N retention. Full article

This work focuses on the study of tribo-mechanical and microstructural properties of TiCN/ZrCN multilayer coatings with a modulation period of 12 nm, obtained by a conventional cathodic arc technique. The coatings were deposited at a temperature of 320 °C using nitrogen and methane reactive gases (N₂/CH₄) mixture in three different proportions. Surface morphology, composition, hardness, adhesion, friction and wear behavior were studied using atomic force microscopy, scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, and scratch and wear tests. The analysis of the coating composition revealed a strict dependence of the carbon content on the CH₄ flow rate. It was found that the coatings with a carbon content of 14.6 at.% and 15.9 at.% consist of crystalline TiZr (C,N) with the presence of amorphous carbon. All the studied TiCN/ZrCN coatings showed improved tribo-mechanical properties compared to TiN/ZrN multilayers obtained under the same deposition conditions. The highest hardness of 40 GPa was obtained for the coating deposited at a N₂/CH₄ flow rate of 370/100 sccm. The lowest wear rate of 3.16 × 10⁻⁶ mm³/N·m under dry sliding conditions was observed in the multilayer coatings deposited at the N₂/CH₄ flow rates of 330/140 sccm. Full article

Camellia hakodae Ninh flowers are an endemic Vietnamese species with limited phytochemical and biological characterization. This study aimed to characterize the phytochemical profile and evaluate antioxidant and anti-inflammatory activities of the total flower extract. Ultrasonic-assisted extraction (UAE) and maceration with methanol and ethanol at different concentrations were carried out to evaluate the efficiency of extracting total phenolic content (TPC) and total flavonoid content (TFC), quantified by colorimetric assays, along with the antioxidant and anti-inflammatory activities of the resulting extracts. The highest TPC (94.9 ± 4.5 mg GAE/g) and TFC (3.1 ± 0.2 mg QE/g) were obtained using UAE with 70% methanol, while maceration with 70% ethanol showed comparable TPC values. The optimized extract exhibited strong antioxidant activity with an IC₅₀ of 29.06 µg/mL, close to that of ascorbic acid (28.16 µg/mL) and significant anti-inflammatory activity in the proteinase inhibition assay (IC₅₀ = 2.72 mg/mL) compared to acetylsalicylic acid (IC₅₀ = 3.16 mg/mL). GC-MS and LC-QTOF-MS/MS analyses revealed diverse metabolites, including phenolic acids, flavonoids, fatty acids, terpenoids, and nitrogen-containing compounds, with representative constituents, such as quinic acid, catechins, flavonol glycosides, and loliolide, providing strong chemical evidence for the observed bioactivities. This integrated study demonstrates that C. hakodae flower is a rich source of multifunctional bioactive compounds and highlights its strong potential for applications in nutraceuticals, functional foods, and cosmeceuticals. Full article

Salt stress is a critical abiotic constraint affecting wheat yield and quality. In this study, we employed pot experiments under controlled salinity (2.8‰ NaCl) and multi-omics approaches to elucidate the regulatory mechanisms underlying grain quality formation in a strong-gluten wheat variety, Jinan 17. Key findings revealed that salt stress caused a significant 41.27% reduction in 1000-kernel weight, while protein content increased by 13.82%. However, bread volume and bread score were reduced by 16.85% and 13.08%, respectively. Multi-omics integration uncovered that salt stress repressed the expression of starch synthesis-related genes (e.g., TraesCS2A03G0349200), diverting carbon skeletons toward amino acid metabolism pathways. This metabolic reprogramming disrupted the glutenin/gliadin ratio (down 14.35%), with high molecular weight glutenin subunits (HMW-GS) synthesis being suppressed, while low molecular weight glutenin subunits (LMW-GS) and gliadin accumulated by 19.28% and 24.76%, respectively, forming a “high extensibility but low elasticity” gluten network. Furthermore, transcriptomic analysis identified significant upregulation of arginine metabolism genes (e.g., TraesCS6A03G0029900), which enhanced osmolyte biosynthesis and exacerbated carbon–nitrogen partitioning imbalances. This study provides novel insights into the molecular mechanisms of flour quality deterioration under saline conditions and identifies critical regulatory nodes for simultaneous improvement of starch synthesis and gluten network architecture in salt-affected wheat breeding programs. Full article

Cultivation of perennial mixtures has emerged as an efficient way to produce a large amount of forage, supporting a sustainable livestock industry. The stability and sustainability of forage production is largely controlled by soil health. However, variation in soil health in perennial mixtures still needs further investigation under diverse conditions. Clarifying the relationships between soil physicochemical properties and microbial community is of great importance in better understanding soil health in perennial cultivated grasslands. The effects of mixing combination of alfalfa with timothy or smooth bromegrass on soil health were evaluated through comparing soil nutrients, enzyme activities, microbial community, and forage yield in alfalfa–grass mixtures and corresponding monocultures after seven years of establishment. Mixtures significantly increased forage dry matter yield by 61.39% and 1188.29% in the alfalfa–timothy mixture compared with alfalfa and timothy monocultures, respectively, and by 54.36% and 736.38% in the alfalfa–smooth bromegrass mixture compared with alfalfa and smooth bromegrass monocultures, respectively. Mixtures enhanced soil organic carbon, total nitrogen, nitrate nitrogen and ammonium nitrogen contents, and urease activity, but reduced microbial alpha diversity. Beneficial taxa, such as Bacillus, Paenibacillus, and Mortierella, were enriched. Soil nitrate nitrogen was identified as a key driver influencing bacterial functional composition, while soil organic carbon, ammonium nitrogen, water, alkaline phosphatase, and sucrase exhibited significant effects on fungal functional composition. This study demonstrated that alfalfa–grass mixtures enhance system productivity by improving soil physicochemical properties and reconstructing soil microbial community. It provides a theoretical basis from the viewpoint of soil health for establishing and managing sustainable cultivated grasslands. Full article

Legume crops, such as the common bean (Phaseolus vulgaris L.), are significant in many Sub-Saharan African (SSA) countries, including Eswatini, due to their numerous health benefits, including high protein, fiber, vitamins, and mineral content. Common beans are a staple food in many parts of the world and play a crucial role in nitrogen fixation, thereby improving soil fertility. A field experiment was conducted at Malkerns research station, Eswatini, using 27 common bean genotypes to assess their ability for N-fixation and water relations using the ¹⁵N and ¹³C natural abundance techniques. The data revealed significant differences among the common bean genotypes. Genotypes Cim-Rm-36 and Mwctz20a-Rm19 recorded an increase in plant growth by (6% and 5.74%), N content (5.69% and 5.97%) and greater C content (6.1% and 5.67%) while genotype Mwctz20a-Rm19 also showed an increase in N-fixation (155.73 kg.ha⁻¹). Genotype Mwctz20a-Rm-4 had the highest grain yield (1747.39 kg.ha⁻¹), while genotype Cim-Rm-14-Als61 had the highest N concentration (3.50%), indicating efficient N uptake. The genotypes with the lowest δ¹³C values (−27.38‰ to −28.06‰) suggested similar water use efficiency among the genotypes. The findings of this study revealed that common beans can make a significant contribution to N fertility under drought conditions. Genotypes Cim-Rm-36, Mwctz20a-Rm19, and Mwctz20a-Rm-4 showed desirable characteristics and can be good candidates for possible inclusion in breeding programs. These results have implications for improving common bean production in drought-prone areas and promoting sustainable agriculture practices. Full article

Jujube (Ziziphus jujuba Mill.) cultivation in arid regions of China faces severe soil constraints, including high alkalinity, low organic matter content, and poor water retention. Although soil amendments have demonstrated potential for improving soil quality, their combined effects on soil–plant–microbe interactions in desert agroecosystems remain poorly understood. This study conducted a three-year field experiment in a desert jujube orchard in southern Xinjiang, China, to evaluate six nitrogen fertilizer management strategies: urea alone (CK) or combined with biochar (NB), bentonite (NP), graphene (NS), biochar plus bentonite (NBP), or microbial inoculants (NW). Soil physicochemical properties, enzyme activities, bacterial community structure, and jujube yield were analyzed. Structural equation modeling (SEM) was employed to elucidate the pathways linking soil amendments to crop productivity. Results showed that NBP was the most effective in improving soil physical structure, significantly reducing bulk density and enhancing water retention capacity compared to the control. The NBP treatment also enhanced soil organic matter (30% increase), available phosphorus (119% increase), and urease activity (44% increase), resulting in the highest jujube yield (7.14 kg per tree). Bacterial community analysis revealed that NBP significantly increased Shannon diversity and enriched Actinobacteriota and Proteobacteria. SEM analysis indicated that urease activity served as a significant mechanistic pathway linking soil organic matter improvements to enhanced crop productivity. These findings demonstrate that combined application of biochar and bentonite with nitrogen fertilizer represents an effective strategy for improving soil quality, enhancing microbial functionality, and increasing crop yield in desert jujube orchards, providing a practical and synergistic amendment combination for sustainable soil management and productivity enhancement in arid agroecosystems. Full article

Temperature and nitrogen fertilizer are key environmental factors that significantly affect rice growth and grain quality. There remains a lack of systematic research on the effects of temperature and nitrogen fertilizer on carbon–nitrogen metabolism during grain-filling, and consequently on the taste quality of rice varieties with different taste characteristics. To bridge this gap, pot experiments were conducted under different temperature and nitrogen fertilizer conditions to investigate the changes in carbon and nitrogen metabolism and the quality of different high-quality and stable-taste rice varieties during the grain filling stage. Our research results indicate that high-temperature conditions inhibit both carbon and nitrogen metabolism; however, the variations differ among rice varieties with differing taste stability. Under both normal and high nitrogen levels, compared to Akita Komachi (AK), a variety with poor taste stability, Jikedao 606 (J 606), a variety with strong taste stability, maintained a certain photosynthetic capacity under high-temperature conditions, with smaller decreases in net photosynthetic rate and soil–plant analysis development values, declining by 4.30–5.59% and 4.30–5.59% respectively. The decline in the activities of nitrate reductase, glutamine synthetase, and glutamate synthase in nitrogen metabolism was relatively small; in comparison, the decrease in the activities of ADP-glucose pyrophosphorylase, granule-bound starch synthase, starch branching enzyme, and starch debranching enzyme in carbon metabolism was comparatively minor. The content of amylose and amylopectin in the grains was maintained, improving the milled rice rate and head rice rate, thereby ensuring strong stability of excellent sensory quality. Under both high-temperature and high-nitrogen conditions, the yields of the two rice varieties were maintained. In summary, variations exist in carbon and nitrogen metabolism among different rice varieties with stable excellent taste under varying temperature and nitrogen fertilizer conditions. These metabolic differences affect starch synthesis in the endosperm, ultimately influencing the stability of rice sensory quality. This study provides a theoretical basis for nitrogen fertilizer application under high-temperature conditions and the cultivation of rice varieties with excellent taste stability. Full article

Light spectral composition plays a central role in regulating plant growth, morphology, nutrient uptake, and pigment biosynthesis, particularly in controlled-environment agriculture. This study investigated the effects of targeted LED spectral modulation, focusing on green light deprivation and different red-to-blue (R:B) ratios at constant photon flux density, on morphological traits, mineral composition, and photosynthetic pigments in Salvia officinalis L. and Cannabis sativa L. grown under controlled conditions. Plants were cultivated under three LED treatments providing equal light intensity but differing in spectral composition. Morphological parameters, mineral nutrients, inorganic anions, and photosynthetic pigments were assessed at harvest. Total biomass production was not significantly affected by the light treatments in either species; however, clear species-specific responses were observed. In S. officinalis, higher R:B ratios promoted stem elongation without affecting leaf number or fresh weight, whereas in C. sativa, the higher R:B ratio significantly increased leaf number. Green light deprivation and red–blue enrichment generally enhanced mineral accumulation and nitrogen content, although the magnitude and direction of these effects varied between species. Photosynthetic pigment responses were more pronounced in hemp, with increased chlorophylls and carotenoids under green light deprivation, while salvia showed a selective increase in carotenoids under higher R:B ratios. Overall, these findings emphasize the importance of species-specific LED spectral optimization to improve physiological performance and nutritional quality in indoor cultivation of medicinal plants. Full article

Dandelion, a herb with medicinal and nutritional properties, was studied for the stability and neuroprotective effects of polyphenols from its flowers, roots, and leaves during in vitro simulated digestion. Using UPLC-QTOF-ESI-MS/MS, 84 phenolic metabolites were identified, with flavonoids being most abundant in flowers and phenolic acids in leaves and roots. In vitro neuroprotection assays revealed that leaf polyphenols exhibited the highest inhibition rates against acetylcholinesterase and lipoxygenase, while flower polyphenols showed the strongest scavenging activity against reactive nitrogen species. After simulated digestion, total phenol and flavonoid contents increased significantly. Notably, polyphenols from all dandelion parts demonstrated the strongest inhibition of acetylcholinesterase during the oral phase, while the small intestine phase showed the greatest inhibition of lipoxygenase and reactive nitrogen species. Moreover, leaf polyphenols maintained the highest inhibitory effect on acetylcholinesterase throughout all digestive stages, suggesting that dandelion leaves are a promising functional food for preventing neurodegenerative diseases. Full article

The use of wood chips in the heating sector leads to the generation of combustion waste with variable properties, which poses challenges for their rational management. To determine the variability of combustion waste, samples were collected over a 13-week period during the heating season, as weekly aggregate samples from a biomass bioheating plant burning wood chips. Three waste fractions were obtained for analysis: residue from the grate (B1), dust from the dust collector (B2), and boiler dust (B3). Dry matter (DM), reaction (pH_KCl), electrolytic conductivity (EC), content of total carbon (TC), total nitrogen (TN), macronutrients (P, K, Mg, Ca, Na), and heavy metals (Fe, Mn, Zn, Cu, Pb, Cd, Cr, Co, Ni) were determined in the collected samples. All waste fractions were characterized by an alkaline reaction. Regardless of the waste fraction, the macronutrient content was dominated by Ca, K, and Mg, with significantly lower levels of P and Na. Among heavy metals, Fe, Mn, and Zn had the highest recorded contents, and the lowest by far was Cd. With respect to sampling dates, the least diversified chemical composition was observed for B1 samples, more diversified for B2, and the most diversified for B3. In turn, regardless of the waste fraction, the most diversified results were observed for Cd and Pb, and the least for pH, DM, and TC. Concerning environmental management of combustion waste, fraction B1 deserves attention, as it was characterized by the richest chemical composition (TN, P, K, Mg, Ca, Na, Mn, Zn, Cu, Co, Ni). However, due to the highest content of undesirable heavy metals (Pb, Cd) and the highest salinity, it requires constant monitoring of the composition. Full article