Search Results (144)

Multi-wheel wall-climbing robots operating on cylindrical inner surfaces are subject to configuration-dependent wheel-surface contacts and nonholonomic rolling constraints, making planar differential-drive or fixed-contact kinematic models insufficient when the active contact topology changes. This study develops a mode-dependent differential-algebraic kinematic model for a four-wheel wall-climbing robot on cylindrical inner surfaces. Given the instantaneous active contact set, the wheel-surface geometry is reconstructed from nonlinear point-on-surface and tangency constraints using an adaptive Levenberg–Marquardt method. The reconstructed contact geometry is then used to assemble normal-velocity compatibility and rolling constraints, yielding an analytical mapping from a nominal body-twist reference to active-wheel speed commands. The model is integrated into trajectory-based motion generation and assessed through multibody co-simulation incorporating contact and friction effects. For unidirectional and S-shaped motions, the axial root-mean-square errors (RMSEs) are 5.6 mm and 11.5 mm, with normalized axial errors of 0.112% and 0.096%, respectively; the circumferential-angle RMSEs are $1.{25}^{\circ }$ and $1.{32}^{\circ }$, with normalized angular errors of 1.39% and 0.73%. These results demonstrate the applicability of the model to contact-dependent geometric reconstruction and wheel-speed command generation under varying multi-wheel contact topologies on cylindrical inner surfaces, and offer an extensible approach to the kinematic modeling of multi-wheel locomotion in cylindrical environments. Full article

Wing icing poses a significant challenge to the safe operation of battery-powered low-altitude aircraft, while conventional electrothermal deicing is constrained by its high electrical power demand. This study investigates a thermoelectric heat pump (TEHP) deicing method that combines Peltier heat pumping with Joule heating to improve deicing energy efficiency. A multiphysics numerical framework coupling icing, fluid flow, electrical conduction, and heat transfer is developed in ANSYS Fluent using Fluent Icing, the Electric Potential module, and user-defined wall heat-flux expressions. Under the investigated representative icing condition and equal electrical power input, the unit-level COP of TEHP deicing is 3.479–5.88% higher than that of conventional electrothermal deicing under stagnant internal-air conditions. With a 5 m/s internal airflow, the COP improvement increases to 15.7–37.69%. At an input current of 1.5 A, increasing the internal airflow velocity from 2.5 to 7.5 m/s improves the TEHP COP by 12.33–19.86% relative to the stagnant condition. These results demonstrate the feasibility of TEHP deicing and highlight the beneficial role of internal-air heat absorption in improving deicing energy efficiency. Full article

Urban–rural transition zones (URTZs) represent critical spatial units where urban expansion interacts with ecosystems. In arid regions, however, the response of ecological environmental quality (EEQ) to rapid urban expansion and spatial restructuring remains insufficiently understood. Taking Xinjiang as a representative arid-region case, this study develops an analytical framework integrating dynamic URTZs identification, EEQ assessment, and the analysis of influencing factors and nonlinear responses to systematically investigate URTZs expansion and EEQ changes across 13 typical urban agglomerations from 2002 to 2022. URTZs were identified using K-means clustering by integrating population density, nighttime light intensity, and impervious surface information. An improved remote sensing ecological index (ARSEI) was then developed by incorporating the abundance index (AI) into the traditional RSEI framework. Finally, XGBoost and SHAP were employed to identify the key determinants of EEQ and reveal their nonlinear responses and interactions. The results showed that: (1) URTZs expanded rapidly and continuously from 2002 to 2022, with their total area increasing by more than threefold and exhibiting a spatial restructuring pattern characterized by expansion from central cities toward multiple nodes. (2) Despite the rapid expansion of URTZs, overall EEQ remained at a relatively high level; however, the grade structure exhibited a trend of “expansion at both ends and contraction in the middle,” intensifying the spatial differentiation of EEQ. (3) XGBoost and SHAP analyses identified precipitation (PRE), population density (POP), digital elevation model (DEM), and slope as major factors explaining the spatial variation in EEQ. Interaction analysis further revealed strong interactions between PRE × DEM and PRE × POP. High EEQ values were primarily distributed in areas characterized by favorable precipitation conditions, moderate elevations, and gentle terrain, indicating that the synergistic effects of hydrothermal conditions and topographic constraints play a significant role in shaping EEQ in URTZs. These findings demonstrate that rapid URTZs expansion in arid regions does not necessarily lead to an overall decline in EEQ but may intensify its spatial differentiation. Therefore, ecological governance of URTZs should shift from a singular focus on controlling urban expansion toward differentiated spatial management that jointly considers hydrothermal conditions, topographic constraints, population concentration, and ecological carrying capacity, thereby promoting coordinated urbanization and ecological conservation. Full article

This study adopts the contingent valuation method (CVM), Logit model, and quantile regression to evaluate the compensation level of public welfare forests and identify the influencing factors of compensation standards from the perspective of forest farmers’ willingness to accept compensation. The results show that the forest farmers’ expected compensation standard ranges from 1034 to 1128 CNY·ha⁻¹·year⁻¹, more than three times the current official compensation standard. Based on forest farmers’ willingness to accept, the current forest ecological compensation level only reaches 30.6%–33.4% of the expected standard, which is insufficient to mobilize the enthusiasm of forest farmers for forest management and protection. Therefore, it is necessary to further raise the public welfare forest compensation standard and implement diversified compensation measures that adapt to the differentiated demands of forest farmers. In addition, analysis of zero-willingness samples reveals that poor policy cognition is the main reason for zero compensation bids among partial respondents, rather than the overall sample. A better understanding of ecological compensation policies can significantly promote farmers’ willingness to accept compensation, suggesting that targeted policy publicity should be strengthened to improve forest protection awareness and policy satisfaction among forest farmers. Furthermore, household age, annual household income, forestland area, forest management cost, and policy understanding degree are core factors affecting compensation willingness. Quantile regression results indicate that these influencing factors show heterogeneous effects at different compensation levels, which provides evidence for the formulation of differentiated compensation schemes. The robustness test and heterogeneity analysis further confirm the reliability of the research conclusions. This study provides a practical reference for governments to optimize forest ecological compensation policies, balance household welfare, and promote sustainable forest resource protection. Full article

Protein family membership may constrain protein thermal stability, but the extent of this effect remains unclear. We reanalyzed a published thermal proteome dataset containing 3917 Arabidopsis thaliana proteins. Proteins within the same family showed significantly smaller pairwise T_m differences than size-matched random groups, and family membership explained 67.6% of total T_m variation. Although thermal stability was generally conserved within families, some paralogs displayed marked divergence beyond that expected from sequence similarity. This exceptional divergence was not associated with duplication mode or overall structural distance, whereas differences in disulfide-bond density showed the clearest structural association. Gene Ontology cellular-component divergence was also positively associated with thermal divergence. Overall, thermal stability is strongly organized at the gene-family level, while exceptional divergence among paralogs appears to arise through heterogeneous, pair-specific structural and functional changes. Full article

Permanent magnet synchronous motors (PMSMs) operating at low speeds are susceptible to parameter mismatches, periodic harmonics, and various internal and external disturbances, which result in steady-state current errors and low-frequency speed oscillations. To address these issues and improve low-speed PMSM performance, an automatic tuning disturbance rejection incremental deadbeat predictive current control (AT-DR-IDPCC) method is proposed. First, an incremental extended-state observer (IESO) is incorporated into the incremental deadbeat predictive current control (IDPCC) framework to estimate and compensate for lumped disturbances caused by resistance and inductance mismatches, thereby improving parameter robustness. Meanwhile, a quasi-resonant controller (QRC) is connected in parallel with the current loop to selectively suppress sixth-order current harmonics induced by inverter nonlinearities and flux harmonics. Furthermore, a deep deterministic policy gradient (DDPG)-based parameter optimization scheme is introduced to automatically tune the controller parameters, overcoming the limitations of conventional trial-and-error tuning and achieving the coordinated optimization of dynamic response, steady-state accuracy, and disturbance rejection capability. Simulation and experimental results demonstrate that, compared with proportional–integral (PI) control and IDPCC incorporating the IESO (IESO-IDPCC), AT-DR-IDPCC reduces the phase current’s total harmonic distortion (THD) by 56.1% and 23.7% while also decreasing the speed fluctuation amplitude by approximately 50% and 20%, respectively. The proposed method significantly enhances the robustness, harmonic suppression capability, and low-speed control performance of PMSM drives. Full article

Background Aflatoxin B1 (AFB1) is a potent hepatotoxic mycotoxin that induces severe oxidative liver damage. Kaempferol (Kae), a natural flavonoid with known antioxidant properties, has unclear protective effects against AFB1-induced hepatotoxicity. This study aimed to evaluate the hepatoprotective role of Kae and elucidate its underlying mechanism using integrated in vivo, in silico, and in vitro approaches. Methods: In vivo (AFB1-challenged mice) and in vitro (hepatocyte) models were employed, combined with network pharmacology, molecular docking, and molecular dynamics simulations. Liver injury indices, oxidative stress markers, antioxidant enzyme activities, and Keap1/Nrf2 pathway expression were assessed. Results: Kae co-treatment reversed AFB1-induced increases in liver index, serum ALT/AST, histological lesions, and reduced antioxidant capacity in mice. Network pharmacology revealed 59 common targets, with NFE2L2 (Nrf2) as a key node. In vitro, Kae pretreatment significantly lowered AFB1-elevated ROS, MDA, ALT, and AST, while restoring GSH and total antioxidant capacity. Kae reversed AFB1-induced Keap1 upregulation and Nrf2 downregulation, and increased mRNA levels of HO-1, NQO1, SOD, GPX1, and CAT. Molecular docking and simulation showed stable Kae–Keap1 binding (−9.6 kcal/mol) with critical hydrogen bonds (VAL-606) and van der Waals contacts. Conclusions: Kae directly binds Keap1, activates Nrf2 signaling, upregulates antioxidant gene expression, and mitigates AFB1-induced oxidative liver injury. These findings support Kae as a promising candidate for preventing AFB1 hepatotoxicity. Full article

In the late laying phase, laying hens often accumulate fat in their bodies due to high-fat diets, which in turn affects their production performance. Bacillus coagulans has good tolerance in the digestive system and is beneficial to intestinal health. The objective of this study was to evaluate the effect of Bacillus coagulans on production performance, lipid metabolism, and ovarian function in late-phase laying hens. The experiment involved 180 Hy-Line Grey laying hens (65 weeks of age) with similar initial egg production rates. The aged hens were randomly assigned to two treatments with six replicates of 15 hens each. A one-way experimental design was employed: CON group (basal diet) and BC group (basal diet supplemented with 3 × 10⁹ CFU/kg of Bacillus coagulans). The research found that adding Bacillus coagulans to feed significantly reduces ADFI and the feed-to-egg ratio, whilst increasing egg production (p < 0.05). Bacillus coagulans supplementation increased the abundance of Firmicutes and decreased the abundance of Actinobacteriota (p < 0.05), while promoting the proliferation of Lactobacillus and Bacillus (p < 0.05). Furthermore, Bacillus coagulans significantly increased the levels of the bile acids GCDCA, TUDCA, THDCA, LCA, and HDCA in the ileum (p < 0.05). Bacillus coagulans not only increased the activity of T-SOD and CAT in the ovaries, as well as the expression of the Nrf2, HO-1, and SOD1 genes (p < 0.05), but also increased the expression of the estrogen receptor ER-α, FSHR and LHR genes (p < 0.05). In conclusion, dietary supplementation with Bacillus coagulans improved production performance by regulating hepatic lipid metabolism and enhancing ovarian function in aged laying hens. Full article

This study evaluated the effects of dietary sea buckthorn flavonoid (SF) supplementation on growth performance, serum biochemical, antioxidant, and immune indices, rumen fermentation, and ruminal bacterial composition in Hu sheep fed a high-concentrate diet. Thirty 6-month-old fattening Hu sheep were randomly assigned to a high-concentrate control diet (HC) or the same diet supplemented with 0.30% SF (HT; n = 15 per group) for 45 days. Compared with the HC group, SF supplementation increased average daily gain (p = 0.04) and reduced the feed conversion ratio (p = 0.01) without affecting average daily feed intake. Serum total protein, alanine aminotransferase, total antioxidant capacity, IgA, IgG, IL-2, IL-8, and IL-1β were increased in the HT group (p ≤ 0.05). Ruminal acetate and valerate concentrations increased (p = 0.01 and p = 0.03, respectively), and total volatile fatty acid concentration showed an increasing tendency (p = 0.06), whereas rumen pH was unaffected. The relative abundances of Succiniclasticum and Acidaminococcus increased in the HT group (p < 0.05), indicating modulation of specific ruminal bacterial taxa. In conclusion, supplementation with 0.30% SF improved growth efficiency, antioxidant status, selected immune indices, and specific rumen fermentation and bacterial responses in Hu sheep fed a high-concentrate diet. However, the isolated increase in serum alanine aminotransferase may indicate hepatic metabolic adaptation or mild liver stress. Dose–response and time-course studies incorporating liver-specific biomarkers and histopathological evaluation are required to clarify the hepatic safety of sea buckthorn flavonoid supplementation. Full article

Mineralization of soil organic carbon (SOC) is an important component of the soil carbon cycle. Studies have shown that rice–fish cocultures increased SOC; however, the question of whether raising aquatic animals with rice affects SOC mineralization remains unresolved. In this study, we conducted a field experiment to test SOC mineralization under three types of rice–aquatic animal cocultures (i.e., rice–fish coculture, RF; rice–crayfish coculture, RC; and rice–turtle coculture, RT) and rice monoculture (RM). SOC fractions, soil aggregate structure and SOC mineralization were determined in the experiment. Total SOC and microbial biomass carbon (MBC) under RT were significantly higher than under other treatments, and no significant differences in other SOC fractions were found among the treatments. For soil aggregates, there were significant differences in the proportions of large macroaggregates (LMA), microaggregates (MiA), and mean weight diameter (MWD) among the treatments. The LMA proportion significantly reduced while the MiA increased under the RT treatment compared to other treatments. SOC mineralization rates significantly differed among the treatments, where the RT and RC treatments had significantly higher mineralization ratios and daily average mineralization rates than the RF and RM treatments. RDA indicated that SOC fractions and soil aggregate structure influenced SOC mineralization. Our results demonstrate that aquatic animals exert differential effects on SOC mineralization, primarily through altering soil aggregate structure and SOC fractions. These findings highlight that the effects of aquatic animals on SOC dynamics should be considered in the assessment of coculture outcomes. Full article

Rice–aquatic animal coculture systems receive both fertilizer-nitrogen (N) and feed-N inputs; however, the impacts of these inputs on N₂O emissions remain unclear. We conducted a field experiment in a rice–turtle coculture (RT) system using a randomized complete block design with seven treatments and three replications. The results of N applications were determined by the ¹⁵N-labeling method, and the N₂O emissions were measured by the static chamber–gas chromatography method. The results showed that 11.20% of fertilizer-N entered the rice, 0.39% entered the turtles, and 8.97% was retained by the soil. For feed-N, 29.9% was used by the rice, 10.13% was assimilated by turtles, and 49.68% remained in the soil (0–20 cm layer). In the subsequent year, fertilizer-N and feed-N retention rates were 6.17% and 37.61% respectively. In the RT system, N₂O emissions did not differ significantly from those in the rice monoculture (RM) system in the rice-growing season; however, they were significantly higher in the RT system than in the RM system in the winter fallow season. N₂O emissions from the winter fallow season accounted for 93.2% of the annual total, during which feed-N and fertilizer-N directly contributed 10.75% and 0.25% of emissions, and their priming effects contributed 48.4% and 5.1%. Our results suggested that assessing N₂O emissions from rice–aquatic animal coculture systems should incorporate year-round monitoring and that feed-N effects should be considered. Full article

Objectives: The objective of this study was to evaluate the efficacy and safety of an autologous vas deferens (AVD) sling for improving early urinary continence after Retzius-sparing robot-assisted radical prostatectomy (RS-RARP). Methods: In this single-center, prospective, randomized trial, 200 patients at high risk for postoperative urinary incontinence were randomized to undergo RS-RARP with or without AVD sling suspension. The primary endpoint was immediate urinary continence, defined as the use of 0–1 safety pads/day within 7 days after catheter removal. Secondary outcomes included continence recovery up to 3 months, EPIC-26 and IPSSs, and subgroup analysis according to the preoperative membranous urethral length (MUL). Multivariable logistic regression was performed to identify predictors of continence recovery. Results: The AVD sling group showed higher immediate (69.0% vs. 55.0%; p = 0.041) and 1-month continence rates (81.0% vs. 67.0%; p = 0.024) than the RS-RARP group. EPIC-26 scores and IPSSs also favored the AVD sling group during the early postoperative period (both p < 0.01). In exploratory subgroup analyses, patients with preoperative MUL < 12 mm appeared to derive greater early continence benefit from the sling procedure. The AVD sling remained independently associated with continence recovery at the immediate (adjusted OR 2.23, p = 0.014) and 1-month (adjusted OR 2.60, p = 0.008) assessments. Differences between groups decreased after postoperative month 2. The operative time was longer in the AVD sling group, whereas complication rates and short-term oncological outcomes were similar between groups. Conclusions: The AVD sling may improve early urinary continence recovery during the first postoperative month after RS-RARP, particularly in high-risk patients with shorter preoperative MUL. Full article

The pronounced heterogeneity of tight sandstone reservoirs in the Sulige Gas Field poses significant challenges to the uniform propagation of multi-cluster hydraulic fractures during horizontal well staged fracturing, often leading to uneven stimulation and compromised productivity. To address this issue, a coupled fluid–solid fracture propagation model based on the displacement discontinuity method (DDM) was developed, incorporating dynamic fluid distribution, rock deformation, and temporary plugging mechanisms. The model was validated against microseismic monitoring data from the Sulige field and subsequently employed to investigate the effects of reservoir heterogeneity—including porosity, permeability, and in situ stress—on multi-cluster fracture growth. Results indicate that permeability and stress heterogeneity exert the most significant influence on fracture non-uniformity, as reflected by increased coefficients of variation in fracture length. Engineering measures such as the use of high-viscosity guar gum fracturing fluids, variable perforation strategies (e.g., 6, 10, and 16 holes per cluster), and optimized temporary plugging parameters (timing of 0.5 with 12 balls) were shown to effectively mitigate these effects and promote more balanced fracture propagation. This study provides a quantitative framework for optimizing fracturing design in heterogeneous tight gas reservoirs and offers practical guidance for enhancing stimulation uniformity and gas recovery efficiency in the Sulige Gas Field. Full article

Owing to their reliance on detailed mathematical modeling, traditional control methods encounter challenges such as high control complexity and low precision when applied to high-speed flight vehicle control under strongly disturbed atmospheric conditions. To address this limitation, this study introduces a data-driven neural network mapping approach into the field of flight vehicle control. By excavating the underlying patterns in operational data and leveraging the nonlinear mapping capability of neural networks, accurate prediction and generation of control commands are achieved, thereby eliminating the dependence on precise mathematical models and offering a novel solution for complex control problems. Building on this foundation, a self-organizing map (SOM) radial basis function (RBF) neural network is proposed. Leveraging the competitive learning mechanism of SOM, it performs adaptive clustering on input samples, dynamically optimizes the number of clusters to determine the number of hidden-layer nodes in RBF, and adopts the SOM cluster centers as the centers of RBF basis functions. This design enables the one-click data-driven determination of both the number of nodes and their corresponding center vectors, significantly simplifying the network structure design process. Meanwhile, to address inherent limitations of this network, such as suboptimal output weights, unoptimized width functions, and the inherent drawbacks of the traditional Moth-Flame Optimization (MFO) algorithm, an Adaptive Enhanced Moth-Flame Optimization (AEMFO) algorithm is developed, drawing inspiration from biological swarm intelligence. By integrating strategies such as adaptive spiral update and elite opposition-based learning, it balances the global exploration and local exploitation capabilities, and performs targeted optimization of the RBF width parameters and output-layer weights. This optimization significantly enhances the accuracy of the network in mapping attitude-control commands in strongly disturbed environments, providing robust support for the stable attitude control of high-speed flight vehicles. Finally, simulation results demonstrate that the proposed method achieves high control accuracy for flight vehicle attitude control under strongly disturbed environments. Full article

Background: Aberrant glycosylation is closely associated with tumor progression, changes in the tumor microenvironment, and chemoresistance. This study aimed to identify prognostic sialylation-related genes in bladder cancer and define the role of ST3GAL6 in gemcitabine–cisplatin resistance. Methods: Molecular subtype analysis, prognostic analysis, and risk model construction were performed for sialylation-related genes using transcriptomic data and clinical information from the TCGA database. GC-resistant bladder cancer cell models were established for transcriptomic sequencing and untargeted metabolomic analysis. Cell proliferation and drug sensitivity assays were performed to evaluate the function of ST3GAL6. The regulatory relationship between IGF2BP3, ST3GAL6, and the PI3K pathway was further assessed by combining database analysis with molecular experiments. Results: Sialylation-related molecular patterns were associated with patient prognosis and tumor microenvironment features, particularly fibroblast-related characteristics, in bladder cancer. The key model gene ST3GAL6 was upregulated in bladder cancer tissues and was closely associated with prognosis. In GC-resistant bladder cancer cells, ST3GAL6 expression was significantly increased and accompanied by enhanced sialylation activity. ST3GAL6 promoted bladder cancer cell proliferation and reduced sensitivity to cisplatin and gemcitabine, at least in part through the PI3K-AKT-mTOR pathway. IGF2BP3 was also upregulated in resistant cells, is positively correlated with ST3GAL6, and may help maintain ST3GAL6’s expression by stabilizing its mRNA. Conclusions: Our findings suggest that aberrant sialylation is involved in bladder cancer progression and GC resistance. The IGF2BP3-ST3GAL6-PI3K/AKT/mTOR signaling axis may contribute to this process and may serve as a potential biomarker and therapeutic target in bladder cancer. Full article