Search Results (1,284)

Nitrogen (N) fertilization critically regulates the storage and availability of soil carbon (C) and N pools. However, the internal mechanism through which stratified N application affects soil organic carbon (SOC) sequestration and soil quality index (SQI) remains unclear. To investigate the effects of stratified N application on C sequestration and SQI in both topsoil and subsoil, this study established six treatments (N_0:0, N_1:0, N_4:1, N_3:2, N_2:3, N_1:4) and analyzed soil biochemical indicators. The results showed that compared to N_1:0, stratified N fertilization did not significantly improve soil C and N content in the 0–20 cm layer. In contrast, the N_2:3 and N_1:4 treatments even led to a significant reduction in soil C and N pools in the topsoil. In the 20–40 cm, compared to N_1:0, stratified N fertilization increased SOC, TN, labile C fractions, N fractions (particulate organic N and microbial biomass N), enzyme activity and C pool management index (CPMI), increasing by 0.52–7.94%, 2.05–8.42%, 4.77–42.59%, 14.46–56.01%, 6.34–45.82%, and 31.26–51.93%, respectively. In 0–20 cm, compared to N_0:0, N application increased SQI by 24.84–45.77%, and N_2:3 and N_1:4 treatments were lower SQI than N_1:0. Furthermore, N_2:3, N_3:2, and N_1:4 treatments in 20–40 cm were higher than other treatments. N fertilizer application drives the synergistic changes in C and N fractions by regulating enzyme activity and stoichiometric ratio, thus affecting CPMI and SQI. Thus, the 3:2 stratified N fertilization (0–20 cm:20–40 cm) method achieves synergistic dual-layer enhancement-maintaining surface C and N pools while boosting subsoil C sequestration and quality-through enzyme-mediated precision regulation of C/N stoichiometry. The study provides a scientific foundation for integrated C emission reduction and cropland quality enhancement in the North China. Full article

Highly permeable and selective membranes are crucial for energy-efficient gas separation. Two-dimensional (2D) graphitic carbon nitride (g-C₃N₄) has attracted significant attention due to its unique structural characteristics, including ultra-thin thickness, inherent surface porosity, and abundant amine groups. However, the interfacial defects caused by poor compatibility between g-C₃N₄ and polymers deteriorate the separation performance of membrane materials. In this study, amino-functionalized g-C₃N₄ nanosheets (CN@PEI) was prepared by a post-synthesis method, then blended with the polymer Pebax to fabricate Pebax/CN@PEI mixed matrix membranes (MMMs). Compared to g-C₃N₄, MMMs with CN@PEI loading of 20 wt% as nanofiller exhibited a CO₂ permeance of 241 Barrer as well as the CO₂/CH₄ and CO₂/N₂ selectivity of 39.7 and 61.2, respectively, at the feed gas pressure of 2 bar, which approaches the 2008 Robeson upper bound and exceeded the 1991 Robeson upper bound. The Pebax/CN@PEI (20) membrane showed robust stability performance over 70 h continuous gas permeability testing, and no significant decline was observed. SEM characterization revealed a uniform dispersion of CN@PEI throughout the Pebax matrix, demonstrating excellent interfacial compatibility between the components. The increased free volume fraction, enhanced solubility, and higher diffusion coefficient demonstrated that the incorporation of CN@PEI nanosheets introduced more CO₂-philic amino groups and disrupted the chain packing of the Pebax matrix, thereby creating additional diffusion channels and facilitating CO₂ transport. Full article

By using the Ekeland variational principle and Nehari manifold, we study the following fractional p-Laplacian Kirchhoff equations: $M\left({\left[u\right]}_{s,p}^p+{\int }_{{\mathbb{R}}^N}V\left(x\right){\left|u\right|}^{p}dx\right)[{(-\Delta )}_p^{s}u+$${V\left(x\right)\left|u\right|}^{p-2}u]={\lambda \left|u\right|}^{q-2}u\ln \left|u\right|,x\in {\mathbb{R}}^N,\left(\mathrm{P}\right)$. In these equations, $\lambda \in \mathbb{R}\setminus \left\{0\right\},$$p\in (1,+\infty )$, $s\in (0,1),sp<N,$$p_s^{*}={\displaystyle \frac{Np}{N-sp}}$, $M\left(\tau \right)=a+b{\tau }^{\theta -1}$, $a,b\in {\mathbb{R}}^{+},$$1<\theta <{\displaystyle \frac{p_s^{*}}{p}}$, $V\left(x\right)\in C({\mathbb{R}}^N,\mathbb{R})$ is a potential function and ${(-\Delta )}_p^s$ is the fractional p-Laplacian operator. The existence of solutions is deeply influenced by the positive and negative signs of $\lambda$. More precisely, (i) Equation (P) has one ground state solution for $\lambda >0$ and $p\theta <q<p_s^{*}$, with a positive corresponding energy value; and (ii) Equation (P) has at least two nontrivial solutions for $\lambda <0$ and $p<q<p_s^{*}$, with positive and negative corresponding energy values, respectively. Full article

The low-temperature impact properties of high-heat-input steels, particularly low-carbon Nb–Ti steel, are significantly influenced by the coarse-grained heat-affected zone (CGHAZ) in welded joints. The microstructure predominantly consists of granular bainitic ferrite (GBF), ferrite side plate (FSP), degenerate pearlite (DP), coarse plate-like ferrite (PF), and limited acicular ferrite (AF). This study investigates the effect of lanthanum (La) addition to Nb–Ti steel, leading to the formation of composite inclusions with a LaAlO₃·TiN core surrounded by MnS/MnC precipitates. Unlike conventional Al₂O₃·MnS inclusions in Nb–Ti steel, these La-modified inclusions promote enhanced AF nucleation. This not only refines prior austenite grains but also reduces detrimental microstructural constituents such as GBF and FSP. As a result, the impact energy at −40 °C significantly improves from 23 J (Nb–Ti steel) to 137 J (Nb–Ti–La steel). Moreover, the inclusions exhibit an increase in size but a decrease in number density. The Nb–Ti–La variant demonstrates a higher AF volume fraction and increased AF density within the CGHAZ. The refined grain structure, along with an increased proportion of high-angle grain boundaries, effectively impedes secondary crack propagation. These microstructural modifications contribute to a substantial improvement in the low-temperature impact toughness of welded joints. Full article

Rheumatoid arthritis (RA) is the most common inflammatory polyarthritis. In addition, 60–80% of patients express anti-citrullinated protein antibodies (ACPAs), which serve as a diagnostic marker for RA. The effector functions of these autoantibodies can be heavily affected by the N-glycosylation of their Fc region. Here we present a comparison of the Fc N-glycosylation of ACPA IgG to that of non-ACPA IgG from the same patients, and of healthy controls, in an IgG isoform-specific manner. We isolated ACPA and normal serum IgG, digested by trypsin, and separated the resulting peptide mixture by a reversed-phase nanoLC coupled to a Bruker Maxis II Q-TOF, and determined the relative abundance of glycoforms. The paired analysis of galactosylation and sialylation of the IgG subclasses of ACPA and non-ACPA IgG has shown a significant, moderate negative correlation with the inflammatory markers, the level of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), as well as with rheuma-factor (RF), but not with the disease activity score (DAS) or cyclic citrullinated peptide specific antibodies (anti-CCP). However, we detected a significant negative correlation between glycosylation and DAS in the non-ACPA IgG fractions. Furthermore, the isoform-specific analysis revealed additional insight into the changes of the glycosylation features of IgG in RA: changes in the frequencies of the bisecting GlcNAc unit between sample groups could be explained by only the IgG1 isoform; while invariance in fucosylation is the result of the superposition of two isoforms with opposite changes. These results highlight the importance of analyzing immunoglobulin glycosylation in an isoform-specific manner. Full article

The epoxy monomer N,1-bis(4-(2-oxiranemethoxy)phenyl)methylamine (HBAP-EP) was synthesized through the Schiff base reaction and epichlorohydrin method, and the HBAP-EP monomer was cured using p-aminobenzene sulfonamide (SAA). Differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarizing optical microscopy (POM) demonstrated that the epoxy monomer exhibits reversible liquid crystal properties, and the liquid crystal fraction of the monomer can reach 14.4% after curing at 120 °C. The fracture toughness of the resin cured at 120 °C can reach 0.93 KJ·m⁻², and its thermal conductivity is 0.3229 W·(m·K)⁻¹, both of which are higher than those of ordinary epoxy resin. Full article

Anaerobic digestion (AD) is an environmentally sustainable approach for managing invasive plants species, mitigating pollution, and generating renewable energy. However, the complex structure of these biomasses limits their biodegradability and necessitates pretreatment to enhance methane production. This study explored the biotransformation of two invasive species, Reynoutria japonica and Phragmites australis, harvested across diverse phenological stages. Bioprocess intensification was achieved through a single-stage process using a hydrolytic–methanogenic consortium under thermophilic conditions (55 °C, 25 days). The impact of harvest timing distinct plant fractions (shoot vs. root) on biogas production was meticulously evaluated. Results revealed progressive biogas production. Notably, winter-harvested shoot fractions exhibited the highest methane-rich biogas, achieving 551.12 ± 33.07 mL/g VS for Reynoutria and 401.42 ± 24.09 mL/g VS for Phragmites. The resulting digestate demonstrates a rich composition of essential macronutrients (N-P-K) vital for plant growth, highlighting its potential as a valuable biofertilizer. Significantly, complete inhibition of seed germination was observed, confirming the process’s efficacy in preventing the further propagation of invasive species. This research underscores that thermophilic anaerobic digestion, coupled with hydrolytic treatment, is a significant advancement in the valorization of invasive biomasses, contributing to both renewable energy production and ecological recovery. Full article

Background/Objectives: With the aging of the population, the number of patients with osteoporosis is increasing worldwide. Osteoporosis results from an imbalance in bone remodeling by osteoblasts and osteoclasts. This study investigated the effects of sake lees and rice koji, traditional Japanese rice-fermented products, on bone metabolism. Methods: Both sake lees extract and rice koji extract increased alkaline phosphatase (ALP) activity, extracellular collagen accumulation, and mineralization of MC3T3-E1 cells. In addition, the intracellular protein levels of Hsp47 and Sec23IP, which are required for collagen maturation and secretion, respectively, were increased during the differentiation. On the other hand, both extracts significantly inhibited osteoclastic differentiation. Furthermore, the effects of freeze-dried sake lees or rice koji extract on osteoporotic bones were examined using twelve-week-old female C3H/HeJ ovariectomized (OVX) mice. Results: The groups of mice fed 20% or 40% freeze-dried sake lees showed significant suppression of the loss in bone volume fraction (BV/TV) and trabecular volume (Tb.V) compared with those fed a normal diet as well as the 40% freeze-dried sake lees-fed group reduced in the loss of trabecular thickness (Tb.Th). Similarly, the rice koji extract-treated mice showed significant inhibition of the loss in BV/TV, Tb.V, and even trabecular number (Tb.N.). Folic acid and S-adenosylmethionine (SAM), which have been reported to be present in sake lees, promoted extracellular collagen production by osteoblasts. Conclusions: In OVX mice, the intake of freeze-dried sake lees or rice koji extract was associated with the attenuation of trabecular bone loss, suggesting potential beneficial effects on bone metabolism. Full article

Freeze–thaw cycles (FTCs) influence soil nitrogen (N) dynamics and soil aggregate stability. However, the driving mechanism affecting aggregate stability from the combined perspective of N components and N distribution by ¹⁵N tracing technology in both bulk soils and soil aggregates remains worth exploring. This study took the farmland Mollisols in Hailun City, Heilongjiang Province, as the research object, and investigated the variations in soil N components and aggregate stability across five freeze–thaw frequencies (1, 3, 5, 9, and 17 cycles) under three freeze–thaw temperatures (−9 °C/5 °C, −18 °C/5 °C, and −26 °C/5 °C) using ¹⁵N tracing technology. The results demonstrated that freeze–thaw frequency and temperature both influenced aggregate stability. Specifically, with the increase in freeze–thaw frequency, soil aggregate stability was reduced through decreasing the proportion of macroaggregates (2–0.25 mm), increasing the proportion of silt + clay fractions (<0.053 mm), and reducing the total N (TN) content of silt + clay fractions under higher freezing temperature (−9 °C/5 °C). In contrast, for lower freezing temperature (−18 °C/5 °C and −26 °C/5 °C), the increased freeze–thaw frequency enhances soil aggregate stability by decreasing the proportion of silt + clay fractions, increasing the proportion of microaggregates (0.25–0.053 mm), and reducing the TN contents of microaggregates and silt + clay fractions. These findings are essential for developing strategies to mitigate the adverse effects of FTCs on soil quality and ecosystem functions in cold regions. Full article

Establishing artificial sand-fixing plantations is a key strategy for combating land desertification and enhancing soil carbon sequestration in arid regions. To evaluate the effects of Corethrodendron scoparium (Fisch. & C. A. Mey.) Fisch. & Basiner. plantations on soil carbon storage along the southern edge of the Tengger Desert, a systematic investigation of the 0–100 cm soil profile was conducted, using mobile sand dunes as the control (CK). The study analyzed dynamic changes in soil carbon fractions and their driving factors during the succession of C. scoparium plantations. After 40 years of vegetation restoration, total soil carbon, soil inorganic carbon (SIC), and soil organic carbon (SOC) contents increased by 0.87-, 0.77-, and 1.27-fold, respectively, while the Carbon Pool Management Index improved by 1.40-fold. Following 10 years of restoration, SIC content, as well as the ratios of particulate organic carbon/SOC, inert organic carbon (IOC)/SOC, and heavy-fraction organic carbon/SOC, increased with soil depth. In contrast, SOC content, the absolute amounts of SOC fractions, and the ratios of dissolved organic carbon/SOC, easily oxidizable organic carbon/SOC, light-fraction organic carbon/SOC, and mineral-associated organic carbon (MAOC)/SOC all showed decreasing trends with depth. Overall, C. scoparium plantations enhanced the contents of both labile and stable SOC fractions. The proportions of IOC and MAOC within SOC rose from 52.21% and 34.19% to 60.96% and 45.51%, respectively, indicating greater stability of the soil carbon pool. Structural equation modeling and redundancy analysis revealed that soil pH, bulk density, and soil water content were significantly negatively correlated with carbon fractions, whereas total nitrogen, vegetation cover, C/N ratio, electrical conductivity, available phosphorus, and alkali-hydrolyzable nitrogen were identified as the main drivers of carbon fraction variation. Full article

Muscle atrophy is defined as reductions in muscle size and function and represents a critical concern affecting elderly populations, immobilized patients, and individuals following specific dietary regimens, such as fasting and low-protein diets. This study investigated the protective effects of Stellaria dichotoma root extract and its isolated bioactive compounds during muscle atrophy using both in vitro and in vivo experimental models. First, S. dichotoma root extract prevented dexamethasone (DEX)-induced atrophy in C2C12 myotubes. Through systematic solvent partitioning and resin chromatography, five compounds (1–5) were successfully isolated from the n-butanol fraction. Dichotomine B (2) was identified as the most abundant and bioactive constituent. Treatment with dichotomine B significantly preserved the myotube diameter, enhanced the fusion index, and maintained the myosin heavy chain protein level while suppressing key atrophic biomarkers, including FoxO3a, MuRF-1, and Atrogin-1, in DEX-treated myotubes. Furthermore, dichotomine B (2) reduced proteolysis in serum-free cultured C2C12 myotubes and in mice subjected to 48 h of fasting, preserving muscle mass and strength. These findings suggest that S. dichotoma root extract and its principal compound, dichotomine B (2), have promising therapeutic potential and provide an opportunity to develop novel pharmacological interventions against muscle wasting through suppression of proteolysis pathways. Full article

Nonylphenols (NPs), widely used as emulsifiers in petroleum production and refining, are compounds of environmental concern, with endocrine-disrupting effects. They can be released during oil extraction and processing, carried into petroleum products, and subsequently emitted during downstream applications such as combustion. Despite these potential pathways, information on their occurrence in petroleum streams remains limited, partly due to the lack of reliable methods for measuring NPs in complex petroleum matrices. In this study, we developed an analytical method combining normal-phase chromatography (NPC), solid-phase extraction (SPE), and liquid chromatography–Orbitrap high-resolution mass spectrometry (LC–Orbitrap-HRMS) for NP determination in crude oils and petroleum products. NPC was performed using alumina (5% water deactivation) as the stationary phase. The column was eluted sequentially with n-hexane, n-hexane/dichloromethane (4:1 and 1:1, v/v), dichloromethane, and dichloromethane/methanol (2:1, v/v). The first three fractions were discarded, and the remaining two fractions were combined and further purified using a C₁₈ SPE cartridge to analysis. The method showed high recovery (82.8 ± 2.6%) and a low detection limit (1.0 ng/g) in crude oil. Application revealed widespread occurrence of NPs, with concentrations up to 784.4 ng/g in crude oils and up to 439.1 ng/g in refined fuels, indicating that these compounds can persist through refining and may be released during downstream use. These results demonstrate that the method is suitable for the routine monitoring of NPs in petroleum-related samples and provide a practical tool for supporting sustainable refining practices and improved environmental management in the upstream oil and gas sector. Full article

Long-term maize (Zea mays L.) intercropping with peanut (Arachis hypogaea L.) (M||P) improves soil aggregate stability and phosphorus (P) availability, sustaining farmland productivity. In contrast, co-ridge planting (R-M||P) further enhances yield. However, the relationship between yield increase and improvements in soil aggregate stability and ecological stoichiometric characteristics under R-M||P remains unclear. Therefore, this study examined the effects of R-M||P on aggregate fractions and stability, bulk density (BD), porosity (Pt), soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), total phosphorus (TP), and inorganic phosphorus, along with the ecological stoichiometric characteristics of C, N, and P. R-M||P substantially increased the proportion of topsoil macroaggregates, both mechanically stable (>0.5 mm) and water-stable (>1 mm), compared with flat planting. Additionally, it enhanced WR_0.25 and mean weight diameter, substantially reduced BD, and increased Pt. Furthermore, R-M||P significantly increased the concentrations of SOC, TN, TP, AP, Ca₂-P, Ca₈-P, Al-P, and Fe-P. It also enhanced the contribution rates of SOC, TN, TP, and AP in macroaggregates, leading to increased storage of carbon (SCS), nitrogen (SNS), and phosphorus (SPS). R-M||P significantly elevated C:N and C:P ratios. Phosphorus application increased SOC and nutrient concentrations, positively regulated C:N, and enhanced C, N, and P storage. However, it negatively influenced C:P and N:P ratios. SOC and AP were the main driving factors affecting the intercropping advantage, with explanatory rates of 33.2% and 22.7%, respectively, under R-M||P. These findings suggest that R-M||P combined with P application enhances yield by promoting aggregate stability, increasing the concentrations and storage of C, N, and P, and establishing a new ecological stoichiometric balance. Full article

Introduction: Total pelvic exenteration (TPE) is a radical procedure for advanced pelvic malignancies involving adjacent organs. The Hugo™ RAS System is a novel robotic platform, but its application in TPE has not previously been reported. We describe the first case of robotic-assisted TPE using Hugo™ RAS in a patient with locally advanced rectal cancer invading the prostate. Methods: A 69-year-old male with mucous and bloody stools was diagnosed with cT4b (prostate, levator ani muscle) N0M0 rectal cancer. After short-course radiotherapy (25 Gy/5 fractions), robotic-assisted TPE was performed. Port placement was planned to coincide with future colostomy and urostomy sites to minimize abdominal wall trauma. En bloc resection was achieved, followed by pelvic reconstruction with a gluteus maximus musculocutaneous flap and fascia lata autograft. Urinary diversion was completed with a robotic intracorporeal Wallace-type ileal conduit. Results: The operation lasted 17 h 56 min, with 175 mL blood loss. Postoperatively, Clavien–Dindo grade IIIa paralytic ileus occurred but was managed conservatively. Pathology revealed pT4b (prostate) N1a M0 disease with negative circumferential margin (11 mm). No recurrence was observed at 9 months. Conclusions: This case highlights the technical feasibility and safety of Hugo™ RAS-assisted TPE. Further clinical experience is needed to confirm reproducibility and oncologic safety. Full article

CoCrFeNiMn HEA-based composites with Cr₃C₂, 15% Ag, and different mass fractions of CaF₂/BaF₂ eutectic fluoride were fabricated by spark plasma sintering. The tribological properties and wear mechanism of the composites were investigated from RT to 800 °C. The friction coefficients of CoCrFeNiMn-Cr₃C₂-Ag-CaF₂/BaF₂ composites decrease from RT to 800 °C except for 400 °C. At 800 °C, with the increasing mass fraction of the eutectic fluoride, the friction coefficient of the composite decreases from 0.53 to 0.25. The wear rates of the composite with 15% CaF₂/BaF₂ eutectic fluoride decrease significantly at high temperatures. The CoCrFeNiMn-Cr₃C₂-Ag-15%CaF₂/BaF₂ composite exhibits the lowest wear rates at 400 °C, 600 °C, and 800 °C, which are 4.47 × 10⁻⁶ mm³/N·m, 5.15 × 10⁻⁶ mm³/N·m, and 2.42 × 10⁻⁶ mm³/N·m, respectively. At low temperatures, the tribological mechanisms of the composites are micro-plowing and micro-cutting, and Ag is formed as a lubricating film to reduce the friction coefficient. At high temperature, fluorides form a transfer film on the wear scar surface, providing a lubricating effect. Also, the oxide layers and chromate are formed on the worn surfaces of the composites, which are beneficial for improving the wear resistance. Based on the mechanical properties and tribological behavior, the CoCrFeNiMn-Cr₃C₂-Ag-15%CaF₂/BaF₂ composite demonstrates the best comprehensive properties. Full article