Search Results (3,527)

Improving the efficiency of photocatalysts for hydrogen production while minimizing the amount of noble metals used is a pressing issue in modern green energy. This study examines the effect of ultra-small Pt additives on increasing the efficiency of the CuO_x-dark TiO₂ photocatalyst used in the hydrogen evolution reaction (HER). Initially, Pt was photoreduced from the hydroxonitrate complex (Me₄N)₂[Pt₂(OH)₂(NO₃)₈] onto the surface of nanodispersed CuO_x powder obtained by pulsed laser ablation. Then, the obtained Pt-CuO_x particles were dispersed on the surface of highly defective dark TiO₂, so that the mass content of Pt in the samples varied in the range from 1.25 × 10⁻⁵ to 10⁻⁴. The prepared samples were examined using HRTEM, XRD, XPS, and UV-Vis DRS methods. It has been established that in the Pt-CuO_x particles, platinum is mainly present in the form of single atoms (SAs), both as Pt²⁺ (predominantly) and Pt⁴⁺ species, which should facilitate electron transfer and contribute to the manifestation of the strong metal–support interaction (SMSI) effect between SA Ptⁿ⁺ and CuO_x. In turn, in the Pt-CuO_x-dark TiO₂ samples, surface defects (O_v) and surface OH groups on dark TiO₂ particles act as “anchors”, promoting the spontaneous dispersion of CuO_x in the form of sub-nanometer clusters with the reduction of Cu²⁺ to Cu¹⁺ when localized near such O_v defects. During photocatalytic HER in aqueous glycerol solutions, irradiation was found to initiate a large number of catalytically active Pt⁰-CuO_x-O_v-dark TiO₂ centers, where the SMSI effect causes electron transfer from titania to SA Pt, thus promoting better separation of photogenerated charges. As a result, ultra-small additives of Pt led to up to a 1.34-fold increase in the amount of released hydrogen, while the maximum apparent quantum yield (AQY) reached 65%. Full article

Climate change and injudicious nitrogen addition alter the soil physico-chemical properties and microbial activity in oligotrophic forest soil, which disrupts the nitrogen cycle balance. Nevertheless, recommended fertilizer forms and levels are considered to be crucial for stable nitrogen application. We established a short-term field trial for the first time using a randomized complete block design under the yellow larch forest, with six treatments applied, including urea CO(NH₂)₂, ammonium chloride NH₄Cl, and sodium nitrate NaNO₃ at concentrations of 10 and 20 kg N hm⁻² yr⁻¹, each extended by three replicates. The gene abundances were measured using quantitative PCR (qPCR), in which the abundance levels of AOA (amoA) and nirS were higher under high CO(NH₂)₂ 2.87 × 10¹⁰ copies g⁻¹ dry soil and low NO₃⁻ 8.82 × 10⁹ copies g⁻¹ dry soil, compared to CK, representing 2.8-fold and 1.5-fold increases, respectively. We found niche partitioning as revealed despite AOA (amoA) increasing in number, AOB (amoA) contributing more to ammonia oxidation while nirS proved opportunistic under stress conditions. This was supported by distinct significant correlations among factors, in which soil urease enzymatic activity (S-UE) was associated with AOA (amoA) and nirK, while AOB (amoA) and nirS positively correlated with NH₄⁺ content and soil potential of hydrogen (pH), respectively. Among the applied treatments, high-level NO₃⁻ increased total nitrogen content and had a significant effect on soil N-acetyl-β-d-glucosaminidase (S-NAG) and soil acid protease (S-ACPT) activity. In summary, we observed an increase in Larix olgensis growth with high nitrogen retention. Full article

The phyllosphere, the aerial part of plants, serves as a crucial habitat for diverse microorganisms. Phyllosphere bacteria can activate protective mechanisms that help plants resist disease. This study focuses on isolating and characterizing phyllosphere bacteria from cucurbits to evaluate their potential in controlling Colletotrichum orbiculare, a pathogen causing anthracnose in cucumbers. Among the 76 bacterial isolates collected, 11 exhibited strong antagonistic effects against C. orbiculare in vitro. Morphological and 16S rRNA analyses identified these isolates as different Bacillus species, including B. vallismortis, B. velezensis, B. amyloliquefaciens, and B. subtilis. These bacteria demonstrated essential plant-growth-promoting and biocontrol traits, such as motility, biofilm formation, phosphate solubilization, nitrogen fixation, and the production of indole acetic acid. Most of the bacterial strains also produced biocontrol compounds such as ammonia, acetoin, siderophores, hydrogen cyanide, chitinase, protease, lipase, and cellulase. The application of these bacteria significantly enhanced cucumber growth in both non-manured and organically manured soils, showing improvements in root and shoot length, chlorophyll content, and biomass accumulation. Additionally, bacterial treatments effectively reduced anthracnose severity, with isolates GL-10 and L-1 showing the highest disease suppression in both soil types. Colonization studies showed that phyllobacteria preferentially colonized healthy leaves over roots and diseased tissues, and they were more effective in manure-amended soils. These results suggest that Bacillus phyllobacteria have strong potential as sustainable bio-stimulants and biocontrol agents, offering an effective approach for enhancing cucumber growth and disease control under both fertilized and unfertilized soil conditions. Full article

This study investigated the hydrogen embrittlement behavior of Fe-28Mn-10Al-1C-(0,3) Cu austenitic low-density steels after hydrogen charging. Electrochemical hydrogen charging and thermal desorption spectroscopy (TDS) were employed to characterize hydrogen desorption behavior and identify hydrogen trap types in cold-rolled (LZ) and annealed (TH) conditions. Uniaxial tensile tests were conducted to obtain mechanical properties and the hydrogen embrittlement index (HEI), enabling quantitative evaluation of hydrogen embrittlement susceptibility. Fracture surface morphology was analyzed to elucidate the underlying embrittlement mechanisms. Results indicate that annealing treatment and Cu addition have negligible effects on the activation energy of reversible hydrogen traps, suggesting similar trap types. The reversible hydrogen content decreased by 0.1 wt.ppm and 0.2 wt.ppm in LZ-3Cu and TH-3Cu, respectively, compared to their Cu-free counterparts, indicating that Cu addition mitigates the accumulation of reversible hydrogen. Annealed specimens exhibited lower HEI values, with the HEI of TH-0Cu decreasing from 21.3% to 13.5% and that of TH-3Cu reaching only 9.6%. Fracture mode transitioned from mixed brittle-ductile to fully ductile with Cu alloying, accompanied by a shift from the coupled the Hydrogen-Enhanced Decohesion (HEDE) and the Hydrogen-Enhanced Localized Plasticity (HELP) mechanism to the HELP-dominated mechanism. Collectively, these findings demonstrate that Cu alloying significantly enhances the resistance of austenitic low-density steels to hydrogen embrittlement. Full article

Electric arc furnace slag is a major by-product of steelmaking, yet its industrial utilization remains limited due to its complex chemical and mineralogical composition. This study presents a hydrogen-based approach to recover metallic components from EAF slag for potential reuse in steelmaking. Laboratory experiments were conducted by melting 50 g of industrial slag samples at 1600 °C and injecting hydrogen gas through a ceramic tube into the liquid slag. After cooling, both the slag and the metallic phases were analyzed for their chemical and phase compositions. Additionally, the reduction process was modeled using a combination of approaches, including the thermochemical software FactSage 8.1, models for density, surface tension, and viscosity, as well as a diffusion model. The injection of hydrogen resulted in the reduction of up to 40% of the iron oxide content in the liquid slag. In addition, the fraction of reacted hydrogen gas was calculated. Full article

Mango (Mangifera indica L.) is a very popular tropical drupe that can be consumed fresh or dried. It is rich in essential nutrients such as vitamins, dietary fibre, and minerals, as well as biologically active substances, with a positive effect on health. However, it can also contain potentially toxic elements, which justifies the need of properly investigating this food product. Commercially available samples of dried mango, as well as the mesocarp and peel of fresh mango, were analysed. Prior to the multi-element analysis by inductively coupled plasma mass spectrometry (ICP-MS), the microwave-assisted sample digestion method using various reagents and reagent mixtures was optimised, showing that a mixture of nitric acid and hydrogen peroxide gave the best recoveries. The results obtained were processed by chemometric methods. The content of elements in the peel was higher than in the mesocarp. The macroelements Ca, K, Mg, and Na were found in the largest proportion, and the micronutrients present in significant quantities were Cu, Zn, and Mn (>3 mg/kg), while toxic elements, which according to the guidelines of The European Food Safety Authority) would represent a danger to human health, were not found in mass fractions above the permissible values. Full article

The aim of the work was to develop a highly effective catalyst for the conversion of furfural into furfuryl alcohol through catalytic transfer hydrogenation, which is an important process for converting biomass-derived compounds into valuable chemicals. A highly mesoporous silica was modified with various zirconium and aluminium precursors to obtain Lewis acid centres. The materials were characterised by nitrogen adsorption, FTIR spectroscopy, pyridine adsorption, thermogravimetry, SEM and XRD. The catalytic properties of the materials versus acid site concentration, alcohol type, zirconium content and reaction time were investigated in a batch reactor. The zirconium propoxide-modified materials appeared to be the most active and selective catalysts in the reaction studied. They showed complete furfural conversion with ca. 99% selectivity of furfuryl alcohol, which was attributed to the predominantly Lewis acidic character of these catalysts. High productivity, 15.2 mol_FA/mol_Zr·h, was obtained for the most active catalyst. Good catalytic stability was confirmed in repeated cycles. The oxide form of zirconium and aluminium species resulted in the mixed Lewis and Brönsted acidity, which encouraged further transformation of furfuryl alcohol into butyl furfuryl ether, angelica lactone and butyl levulinate. The elaborated catalyst offers a promising approach for converting renewable resources into industrially relevant chemicals. Full article

Background: Aggregatibacter actinomycetemcomitans JP2 genotype is a virulent pathogen linked to severe periodontitis and systemic diseases. Honey and royal jelly (RJ) have demonstrated bioactive properties against this microorganism. This study aims to assess the bioactive properties of honeys and RJ against this key periodontal pathogen and to preliminarily identify key compounds with antibacterial potential. Methods: The antibacterial activity of honeys and commercial products (manuka, L-Mesitran^® as a medical-grade honey-based formulation (MGHF), and Honix^® RJ) against A. actinomycetemcomitans JP2 was evaluated using the agar well diffusion method and microdilution assays. Extensive physicochemical characterization (e.g., hydrogen peroxide level, total phenolic content, and total flavonoid content) was conducted to correlate the bioactive compounds with the antimicrobial activity. Results: All tested samples exhibited varying antibacterial potency, with inhibition zones ranging from 21 to 37 mm. The MICs ranged from 40.7 to 104.3 mg/mL. MGHF, RJ, and multifloral honeys showed the lowest MICs. The pH of six out of eight samples could not induce enamel decalcification while the pH of three samples may not influence cementum demineralization. Vitamin C, zinc, magnesium, and potassium were present in measurable quantities, and were not associated with significant antibacterial activity. MGHF showed the highest hydrogen peroxide activity and TFC values. TFC and H₂O₂ content were statistically correlated with lower MIC values. Conclusions: Honey and RJ showed antibacterial activity against A. actinomycetemcomitans JP2, partly attributed to their content of hydrogen peroxide and flavonoids. Clinical trials are needed to confirm the potential role of honey, RJ, and their bioactive compounds in managing periodontitis. Full article

Oxidative stress is a major contributor to skin aging and related disorders. This study comparatively evaluated the bioefficacy of Schinus terebinthifolius Raddi leaf extracts prepared using three extraction techniques: conventional extraction (CE), accelerated solvent extraction (ASE), and pulsed electric field (PEF) extraction, with 50% (v/v) ethanol and water as green solvents. Among all tested conditions, the CE-derived extract (C-4), obtained with 50% (v/v) ethanol for 120 min, exhibited the highest extraction yield (29.7%). It also showed the highest total phenolic (668.56 ± 11.52 mg gallic acid equivalent (GAE)/g dry material (DM)) and flavonoid content (2629.92 ± 112.61 mg quercetin equivalent (QE)/100 g DM), and potent antioxidant activity against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical (12,645.50 ± 60.31 µmol Trolox equivalent (TE)/g DM) and oxygen radical absorbance capacity assay (ORAC: 7180.27 ± 101.79 µM TE/100 g DM). Liquid Chromatography coupled with Mass Spectrometry (LC-MS) analysis revealed a diverse phytochemical profile rich in polyphenols, including gallic acid, p-coumaric acid, rutin, rosmarinic acid, caffeic acid, and epicatechin. Cellular assays in hydrogen peroxide (H₂O₂)-induced HaCaT keratinocytes demonstrated that C-4 extract significantly enhanced cell viability and upregulated endogenous antioxidant genes (superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GPX)), with effects comparable to established antioxidants such as epigallocatechin gallate (EGCG) and ascorbic acid. These findings highlight the influence of extraction parameters on phytochemical yield and biological activity, supporting the potential application of CE-derived S. terebinthifolius extracts as effective, sustainable ingredients for cosmeceutical formulations targeting oxidative stress-mediated skin aging. Full article

Selenium is an important trace element with certain antioxidant effects. Nano-selenium, as a novel selenium source, has the advantages of strong biological activity, high absorption efficiency, and low toxicity. The aim of the present study was to compare the protective effects of sodium selenite and nano-selenium on intestinal oxidative stress induced by hydrogen peroxide (H₂O₂) in mice. A total of 60 female mice were randomly divided into 6 groups with 10 replicates per group and 1 mouse per replicate (n = 10). The first three groups were as follows: the Control group (C), fed with basal diet; the sodium selenite group (SS), basal diet + 0.3 mg·kg⁻¹ sodium selenite; and the nano-selenium group (NS), basal diet + 0.3 mg·kg⁻¹ nano-selenium. The latter three groups (CH, SSH, NSH) were fed the same diet as the former three groups, but the last 10 days of the experiment were fed with drinking water containing 0.3% H₂O₂ to induce oxidative stress. The results showed that under normal conditions, the supplementation with sodium selenite or nano-selenium decreased the spleen index of mice; sodium selenate up-regulates GPX3 expression in the ileum, and increases T-SOD in the colon of mice; and nano-selenium up-regulated GPX1 expression but decreased T-AOC in the jejunum. After drinking water treated with H₂O₂, H₂O₂ increased the expression of intestinal inflammatory factors and selenium proteins, such as IL-1β and SOD in jejunum, IL-1β, NF-κB, IL-10, TXNRD1, TXNRD2, GPX1, GPX3, GPX4, and CAT in ileum, and IL-1β and SOD in colon. At the antioxidant level, H₂O₂ decreased T-AOC in the jejunum. In the H₂O₂ treatment, sodium selenite and nano-selenium increased the ratio of VH to CD (VH/CD) in jejunum; sodium selenite up-regulated the expression of TXNRD1 in jejunum, down-regulated the expression of GPX3 in ileum, at the antioxidant level, decreased the T-SOD and T-AOC in colon, and increased the content of MDA in ileum; and nano-selenium down-regulated the expression of TXNRD1 in colon. At the same time, the expression of IL-1β, NF-κB, IL-10, TXNRD1, TXNRD2, GPX1, GPX4, and CAT can be restored to normal levels by selenium supplementation. According to the results, drinking H₂O₂ induced intestinal oxidative stress in mice to a certain extent, and selenium supplementation mitigated the destructive effect of H₂O₂ on the intestinal morphology of mice jejunum and restored the level of related inflammatory factors, and had a positive effect on antioxidants. Full article

Drought stress is a major abiotic constraint that severely restricts the growth of Medicago falcata L. by inducing the accumulation of reactive oxygen species (ROS) in plants. WRKY transcription factors (TFs) play a key role in regulating plant responses to drought stress. In this study, we investigated the role of the MfWRKY40 gene in drought tolerance. Under mannitol and ABA stress treatments, MfWRKY40-overexpressing lines (OEs) showed significantly longer primary roots, increased lateral roots, and higher fresh weight compared to wild-type (Col) lines, indicating significantly enhanced growth and drought tolerance. Similarly, under soil drought conditions, transgenic Arabidopsis thaliana exhibited enhanced drought tolerance. NBT staining demonstrated decreased ROS accumulation in transgenic lines after stress treatment. Correspondingly, the MfWRKY40-overexpressing lines displayed significantly lower levels of hydrogen peroxide (H₂O₂), superoxide anion (O₂⁻), and malondialdehyde (MDA) compared to Col, along with elevated activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), as well as increased proline (Pro) content. Furthermore, MfWRKY40 upregulated the expression of antioxidant enzyme genes (AtPOD3, AtSOD4, and AtCAT1) and modulated the expression of other drought-related genes. In summary, our results demonstrate that MfWRKY40 enhances drought tolerance in A. thaliana by improving ROS scavenging capacity. This study provides a theoretical foundation for further exploration of MfWRKY40’s functional mechanisms in drought stress adaptation. Full article

Cadmium (Cd) is a major co-occurring, highly toxic heavy metal in uranium (U) tailings that poses synergistic risks to ecological and human health. This study aimed to investigate the effects of Cd on U accumulation and phytotoxicity in plants using radish (Raphanus sativus L.) as a model organism under hydroponic conditions. Treatments included U alone (25 μM and 50 μM), low-concentration Cd alone (10 μM), and U + Cd co-treatments (U25 + Cd and U50 + Cd). Results revealed that exposure exerted minimal phytotoxicity, whereas U treatment induced severe root toxicity, characterized by cell death and an 11.9–63.8% reduction in root biomass compared to the control. Notably, U + Cd co-treatment exacerbated root cell death and biomass loss relative to U alone. Physiologically, elevated U concentrations significantly increased superoxide anion radical (O₂⁻) production rate, hydrogen peroxide (H₂O₂) content, and malondialdehyde (MDA)—a marker of oxidative damage—inducing cellular oxidative stress. Under U + Cd co-treatment, O₂⁻ production, H₂O₂ content, and MDA levels in radish roots were all significantly higher than under U alone. Concurrently, activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], and peroxidase [POD]) were lower in U + Cd-treated roots than in U-treated roots, further exacerbating oxidative damage. Regarding heavy metal accumulation, the content of U in radish under U + Cd treatment was significantly higher than that in the U treatment group. However, no significant differences were observed in the expression of uranium (U)-related transport genes (MCA1, MCA3, and ANN1) between the single U treatment and the U-Cd co-treatment. Notably, the inhibitory effect of NRAMP3—a gene associated with Cd transport—was weakened under the coexistence of U, indicating that U exacerbates toxicity by promoting Cd transport. This study shows that Cd appears to enhance the accumulation of U in radish roots and exacerbate the phytotoxicity of U. Full article

The brewing industry generates significant organic waste, much of which remains underutilized despite its potential for energy recovery. This study assesses the feasibility of anaerobic co-digestion (AcoD) using brewers’ spent grain (BSG) from the craft beer production process and cattle manure from feedlots. Thermogravimetric analysis confirmed similar volatile solids content in both substrates, validating BSG as a viable feedstock. AcoD trials were conducted in 20 L biodigesters under dry and ambient conditions over 40 days. Methane yields reached 25 mL CH₄ gVS⁻¹ at a 1:1 inoculum–substrate ratio fresh matter basis and 67.33 mL CH₄ gVS⁻¹ at 2.5:1, indicating that higher inoculum levels enhance methane production. Kinetic modeling using Modified Gompertz, Logistic, and other microbial growth-based models showed that the Logistic model best represented the methane production trends. The detection of hydrogen sulfide in the biogas emphasizes the need for effective filtration. Overall, this work highlights AcoD as a promising approach for organic waste valorization and renewable energy generation in the craft brewing sector, supporting circular economy practices and contributing to environmental and economic sustainability. Full article

Background/Objectives: Ecballium elaterium is a widely distributed species and is one of the earliest recorded in traditional medicine. With global temperatures rising, this study aimed to investigate the changes in E. elaterium plantlets subjected to thermal stress. The goal was to understand how thermal stress affects morphology, physiology, and bioactive metabolite production, both for ecological adaptation and potential therapeutic applications. Methods: Seedlings were cultivated under controlled conditions and subjected to either the control temperature (22 °C) or the heat stress temperature (35 °C) for one week. Morphological and anatomical traits were assessed, along with physiological parameters such as chlorophyll content, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), L-proline, soluble sugars, and total phenolic content. Methanolic leaf extracts from both groups were analyzed via LC-HRMS/MS and examined in vitro for cytotoxic activity against three human cancer cell lines: MCF-7 (breast), DU-145 (prostate), and SH-SY5Y (neuroblastoma). Results: Heat stress reduced dry mass and stomatal density but increased the diameter of the root transition zone, indicating anatomical adaptation. Leaves exhibited elevated oxidative stress markers and altered metabolite accumulation, while the roots showed a more integrated stress response. LC-HRMS/MS profiling revealed significant shifts in Cucurbitacin composition. Extracts from heat-stressed plants displayed stronger cytotoxicity, particularly toward DU-145 and SH-SY5Y cells, correlating with higher levels of glycosylated Cucurbitacins. Conclusions: E. elaterium demonstrates organ-specific thermotolerance mechanisms, with heat stress enhancing the production of bioactive metabolites. These stress-induced phytochemicals, especially Cucurbitacins, hold promise for future cancer research and therapeutic applications. Full article

Salt–alkaline soil poses a significant challenge to soybean productivity. While plant growth-promoting rhizobacteria (PGPR) offer a sustainable strategy for stress mitigation, their field-level application remains underexplored. Here, a field experiment was conducted in the Yellow River Delta of Shandong, China, a typical salt–alkaline region. In this study, we evaluated the effectiveness of Bacillus velezensis 41S2 in enhancing soybean performance under salt–alkaline soil through integrated field trials and transcriptomic analysis. Inoculation with strain 41S2 significantly improved plant biomass, yield components, and seed yield under salt–alkaline soil, and notably increased seed protein and isoflavone contents. Physiological analyses revealed that strain 41S2 markedly reduced hydrogen peroxide (H₂O₂) accumulation, indicating alleviation of oxidative stress. Moreover, strain 41S2 modulated the levels of soluble sugars and amino acids, contributing to osmotic regulation and carbon–nitrogen (C-N) metabolic balance. Transcriptome profiling further indicated that strain 41S2 upregulated genes involved in antioxidant response, C–N metabolism, and phenylpropanoid biosynthesis, highlighting its role in coordinating multilayered stress response pathways. Overall, these findings highlight the potential of B. velezensis 41S2 as a multifunctional bioinoculant for improving salt tolerance and presents a promising tool for sustainable crop production and ecological restoration in salt–alkaline soil. Full article