Search Results (598)

In order to improve the acoustic performance of honeycomb sandwich structures, a Helmholtz-type honeycomb sandwich acoustic metamaterial (HHSAM) was proposed. The theoretical and finite element models were established by calculating the acoustic impedance of multiple parallel Helmholtz resonators (HR). By comparing the sound absorption of the single and multiple HR, it was found that the simulation results were basically consistent with the theoretical calculations. The sound absorption and insulation performance of the honeycomb panels, the honeycomb perforated panels, and the HHSAM structure were compared through impedance tube experiments. The results showed that, over a wide frequency range, the acoustic performance of the HHSAM structure was superior to that of the other two structures. Under scattered sound field conditions, the reverberation room results showed that the sound absorption of the HHSAM structure was better than that of the honeycomb panel in the frequency range of 100–5000 Hz. The noise reduction coefficient (NRC) of the honeycomb panel was 0.1, indicating almost no sound absorption effect in engineering. The NRC of the HHSAM structure could reach 0.35. In terms of sound insulation, the HHSAM structure was more prominent in the 400–4000 Hz range than the honeycomb panel. In the frequency range of 500–1600 Hz, the transmission loss of the HHSAM was 5 dB higher than that of the honeycomb panel. Full article

Sheath blight (ShB), caused by the necrotrophic fungus Rhizoctonia solani, is one of the most serious rice diseases worldwide. In this study, we successfully grafted salicylic acid (SA) onto mesoporous silica nanoparticles through an amide-bond coupling method, forming functionalized MSN-SA nanoparticles. Physicochemical characterization showed that the MSN-SA nanoparticles were spherical, with an average particle size of approximately 30 nm and an SA loading rate of around 7.21%. The assessment of ShB resistance revealed that both SA and MSN-OH treatments were capable of inducing resistance to a certain extent. When SA and MSN-OH were applied in combination, the resistance was further augmented, indicating an additive effect between them. Intriguingly, MSN-SA treatment (50% in Lemont) exhibited a higher and more durable control efficacy compared with SA + MSN-OH treatment (33%). Moreover, field experiments demonstrated that the MSN-SA was safe for rice, and under severe disease conditions, it could recover 16.7% of the yield loss, thus highlighting its substantial application value. Further transcriptome analysis and physicochemical assays suggested that MSN-SA released SA in a slow and continuous manner, thus persistently activating the immune response, and that MSN-SA integrated the effects of SA and MSN-OH, thereby enhancing the ShB resistance. Altogether, our results provide new perspectives and a novel nanomaterial-based immune elicitor for the green control of ShB. Full article

This study investigates the mesostructural damage evolution and creep deformation mechanisms in bedded rock salt through integrated scanning electron microscopy (SEM) and multistage creep experiments. Utilizing a self-developed in situ observation system coupled with digital image correlation (DIC) analysis, the microstructural heterogeneity, strain localization, and damage propagation patterns in the rock were systematically characterized. The results revealed distinct microstructural contrasts between rock salt and argillaceous interlayers, with interfacial regions exhibiting pore-rich, interconnected structures due to crystal gradation disparities. Creep damage initiation predominantly occurred in pure rock salt domains, manifesting as transgranular fractures and intercrystalline slip, followed by crack propagation into salt–mudstone interfaces governed by shear dilatancy. The integration of mesoscale structural characterization with macroscopic mechanical behavior establishes a framework for predicting the long-term stability of bedded salt formations under operational loads. Full article

The limitations of traditional, autologous bone grafts, such as the scarcity of donor material and the risks of secondary surgical trauma, have spurred the development of alternatives for the repair of large bone defects. Bionic bone scaffolds fabricated via fused deposition modeling (FDM)—a three-dimensional (3D) printing technique—are considered promising. While gyroid-structured scaffolds mimic the complex micro-architecture of cancellous bone, their application in FDM 3D printing remains understudied. Furthermore, no consensus has been reached on the ideal pore size for gyroid scaffolds, which is influenced by the infill density. In this study, we fabricated five groups of polycaprolactone/hydroxyapatite (PCL/HA) scaffolds with different infill densities (40%, 45%, 50%, 55%, and 60%) using a solvent-free filament preparation method. Scanning electron microscopy (SEM) observation showed that all scaffolds exhibit an interconnected porous structure. The scaffold with the 55% infill density, featuring a pore size of 465 ± 63 μm, demonstrated optimal hydrophilicity and mechanical properties comparable to natural cancellous bone. In addition, this scaffold supported cellular bridging within its pores and showed the highest alkaline phosphatase (ALP) activity and calcium salt deposition. Our findings offer novel insights into the design of gyroid-like scaffolds and their fabrication via FDM, paving the way for potential clinical applications. Full article

Soil adhesion is one of the basic physical properties of soil. The existence of soil adhesion will cause additional energy consumption of transport vehicles, which is an urgent scientific problem to be solved. In this paper, rubber tires are used as test materials, and the adhesion between rubber tires and different soils is measured by the improved adhesion test device. The rubber surface after the test is processed and analyzed by image analysis software. The results showed that the soil adhesion increased with the increase in soil moisture content and reached the maximum when it was close to the liquid limit. The maximum adhesion increased with the increase in soil clay content. The image processing analysis showed that the watermark area on the rubber surface will gradually increase with the increase in soil moisture content. According to the test results and the characteristics of soil colloid, the electric double-layer theory was introduced to establish the contact, adhesion, and separation model of the rubber–soil interface, and the adhesion mechanism of the rubber–soil interface was expounded. This study will promote the study of soil adhesion and provide a reference for estimating the additional energy consumption caused by adhesion during transportation. Full article

Clostridium ljungdahlii is a model acetogenic bacterium utilized for ethanol production from syngas, with its growth and ethanol synthesis being profoundly influenced by fermentation pH. However, the mechanistic basis of this pH-dependent regulation remains poorly understood. In this study, we systematically investigated the impact of pH on the growth and metabolic profile of C. ljungdahlii under controlled pH conditions using CO as the sole carbon and energy source. At pH 6.0, C. ljungdahlii consumed around 6.0 M carbon monoxide, producing 413 ± 43 mM acetate, 288 ± 35 mM ethanol, and 17 ± 2 mM 2,3-butanediol, with a maximum optical density (OD) of 15.9. In contrast, at pH 5.3, the strain exhibited enhanced metabolic activity, consuming around 9.6 M carbon monoxide and generating 235 ± 24 mM acetate, 756 ± 26 mM ethanol, 38 ± 4 mM 2,3-butanediol, and 28 ± 7 mM lactate, achieving a maximum OD of 30. This represents an approximate twofold increase in both ethanol production and biomass accumulation compared to pH 6.0. Proteomic and parallel reaction monitoring (PRM) analyses demonstrated that the expression levels of key enzymes in central metabolic pathways were marginally higher at pH 6.0 than at pH 5.3, indicating that the observed physiological enhancements were not attributable to differential enzyme expression but likely stemmed from variations in ATP synthesis efficiency. Further optimization experiments revealed that the optimal pH for growth and ethanol production by C. ljungdahlii under CO-sufficient and nutrient-replete conditions is approximately 5.3. These findings provide critical insights into the pH-dependent metabolic regulation of C. ljungdahlii and establish essential parameters for scaling up syngas fermentation for ethanol production. Additionally, this study offers a foundation for further exploration of the unique proton motive force-driven ATP synthesis system in C. ljungdahlii and its broader implications for metabolic network regulation. Full article

Named entity recognition in online medical consultation aims to address the challenge of identifying various types of medical entities within complex and unstructured social text in the context of online medical consultations. This can provide important data support for constructing more powerful online medical consultation knowledge graphs and improving virtual intelligent health assistants. A dataset of 26 medical entity types for named entity recognition for online medical consultations is first constructed. Then, a novel approach for deep named entity recognition in the medical field based on the fusion context mechanism is proposed. This approach captures enhanced local and global contextual semantic representations of online medical consultation text while simultaneously modeling high- and low-order feature interactions between local and global contexts, thereby effectively improving the sequence labeling performance. The experimental results show that the proposed approach can effectively identify 26 medical entity types with an average F1 score of 85.47%, outperforming the state-of-the-art (SOTA) method. The practical significance of this study lies in improving the efficiency and performance of domain-specific knowledge extraction in online medical consultation, supporting the development of virtual intelligent health assistants based on large language models and enabling real-time intelligent medical decision-making, thereby helping patients and their caregivers access common medical information more promptly. Full article

Background/Objectives: BuZhong Yiqi Formula (BZYQF) has significant ameliorative effects on type 2 diabetes mellitus (T2DM). However, its efficacy in alleviating the hyposalivation caused by T2DM needs to be confirmed, and its mechanism is unclear. Methods: Network pharmacology and molecular docking were combined to analyze the molecular mechanism by which BZYQF alleviates T2DM-caused hyposalivation. A T2DM rat model was induced to evaluate the efficacy of BZYQF. The total saliva before and after acid stimulation was collected to determine the salivary flow rate and salivary alpha-amylase (sAA) activity. The parotid (PG) and submandibular glands (SMG) of experimental rats were removed to perform histopathology observation, biochemical indicator determination, and expression detection of signaling molecules in the salivary secretion pathway. Results: The present study screened out 1014 potential targets of BZYQF regarding the treatment of T2DM. These targets were mainly involved in the formation of the receptor complex, exercising the neurotransmitter receptor activity and regulating secretion. They were significantly enriched in the salivary secretion pathway of β1-AR/PKA/AMY1 and CHRM3/IP3R/AQP5. Furthermore, in BZYQF, nine validated compounds were able to dock into the active site of β1-AR, and three validated compounds were able to dock into the active site of CHRM3. Animal experiments confirmed that BZYQF significantly reduces fasting blood glucose, total cholesterol and triglyceride levels; enhances insulin level and HOMA-IS (p < 0.05); and increases salivary flow rate (Basal: increase from 21.04 ± 14.31 to 42.65 ± 8.84 μL/min, effect size of Cohen’s d = 6.80, p = 0.0078; Stimulated: increase from 36.88 ± 17.48 to 72.63 ± 17.67 μL/min, effect size of Cohen’s d = 7.61, p = 0.0025) and sAA activity (Basal: increase from 0.68 ± 0.32 to 2.17 ± 0.77 U/mL, effect size of Cohen’s d = 9.49, p = 0.0027; Stimulated: increase from 1.15 ± 0.77 to 4.80 ± 1.26 U/mL, effect size of Cohen’s d = 13.10, p = 0.0001) in basal and stimulated saliva in T2DM rats. Further mechanistic studies revealed that BZYQF reduces glucose and lipid accumulation, enhances acetylcholine content, improves pathological lesions and inflammation, and significantly increases the expression of salivary secretion pathway signaling molecules, including PKA, IP3R, β1-AR, AQP5, CHRM3, and AMY1 in the PG and SMG of T2DM rats (p < 0.05). Conclusions: The present study demonstrated that BZYQF is able to alleviate T2DM-caused hyposalivation by improving glucose metabolism and activating the salivary secretion pathway in the PG and SMG of T2DM rats. This study might provide a novel rationale and treatment strategy for BZYQF in diabetes-induced hyposalivation in a clinical setting. Full article

The advent of third-generation (3G) gravitational-wave (GW) detectors opens new opportunities for multi-messenger observations of binary neutron star merger events, holding significant potential for probing the history of cosmic expansion. In this paper, we investigate the holographic dark energy (HDE) model by using the future GW standard siren data observed from the 3G GW detectors and the short $\gamma$-ray burst THESEUS-like detector joint observations. We find that GW data alone can achieve a relatively precise estimation of the Hubble constant, with precision of $0.2$–$0.6\%$, but its ability to constrain other cosmological parameters remains limited. Nonetheless, since the GW data can break parameter degeneracies generated by the mainstream EM observations, CMB + BAO + SN (CBS), GW standard sirens play a crucial role in enhancing the accuracy of parameter estimation. With the addition of GW data to CBS, the constraints on cosmological parameters $H_0$, c and ${\Omega }_{\mathrm{m}}$ can be improved by 63–$88\%$, 27–$44\%$ and 55–$70\%$. In summary, observations of GW standard sirens from 3G GW detectors could be pivotal in probing the fundamental nature of dark energy. Full article

Contact-electro-catalysis (CEC) has emerged as a promising catalytic methodology, integrating principles from solid-liquid triboelectric nanogenerators (SL-TENGs) into catalysis. Unlike conventional approaches, CEC harnesses various forms of mechanical energy, including wind and water, along with other renewable sources, enabling reactions under natural conditions without reliance on specific energy inputs like light or electricity. This review presents the basic principles of CEC and discusses its applications, including the degradation of organic molecules, synthesis of chemical substances, and reduction of metals. Furthermore, it explores methods to improve the catalytic efficiency of CEC by optimizing catalytic conditions, the structure of catalyst materials, and the start-up mode. The concluding section offers insights into future prospects and potential applications of CEC, highlighting its role in advancing sustainable catalytic technologies. Full article

Eccentric silo is an extremely common type of silo, but it is still unclear how to accurately control the discharge by adjusting eccentric orifices, limiting the application and development of eccentric silo. In this study, the rice particle discharging process on silos with different eccentricities was simulated by the discrete element method (DEM), and the influence mechanism of orifice eccentricity on silo discharge rate was analyzed. The results show that eccentricity has a direct influence on the particle volume fraction and vertical velocity that determine the discharge rate of the silo. In fully eccentric silo, it is not easy for particle flow to achieve balance, particles will pass through outlet with more kinetic energy. Moreover, continuous force network cannot be formed between particles with shear resistance, resulting in weak interlocking action between particles. The orientation of particle in fully eccentric silo is more vertical, especially near the silo wall, which will produce larger local particle volume fraction above the orifice. When the eccentricity exceeds the critical eccentricity, the sparse flow area on the discharge orifice becomes larger, and the particle acceleration area increases accordingly. Research findings may offer valuable insights for the accurate control of discharge rate of eccentric silo, as well as for optimizing silo design. Full article

Background: Despite the rapid development of nanoemulsions in recent years, no method has been established for the preparation of milbemycin oxime nanoemulsions. Milbemycin oxime is a widely used macrolide antibiotic in veterinary medicine, particularly for treating parasitic infections in animals such as dogs. However, its poor solubility in water limits its bioavailability and therapeutic efficacy. Developing a nanoemulsion formulation can enhance its solubility, stability, and bioavailability, offering a more effective treatment option. Methods: In this experiment, oil-in-water (O/W) milbemycin oxime nanoemulsions were successfully prepared by the phase inversion composition (PIC) method using ethyl butyrate as the oil phase, Tween-80 as the surfactant, and anhydrous ethanol as the co-surfactant. The region of O/W nanoemulsions was identified by constructing a pseudo-ternary phase diagram and, based on this, was screened by determining the droplet size, polydispersity coefficient, and zeta potential of each preparation. Results and Conclusions: The finalized formulation had a 2:1 ratio of surfactant to co-surfactant and a 7:3 ratio of mixed surfactant to oil, and its droplet size, polydispersity index (PDI), and zeta potential were 12.140 ± 0.128 nm, 0.155 ± 0.015, and −4.947 ± 0.768 mV, respectively. Transmission electron microscopy confirmed the spherical uniform distribution of droplets, and the nanoemulsions passed thermodynamic stability tests. The in vitro release of milbemycin oxime nanoemulsions followed first-order kinetic equations. In conclusion, nanoemulsions are an interesting option for the delivery of poorly water-soluble molecules such as milbemycin oxime. Full article

The thioredoxin (Trx) system is one of the most significant systems in living organisms as it regulates cellular redox reactions and plays a pivotal protective role within the cell by promoting redox homeostasis. Trx and thioredoxin reductase (TrxR) are the core oxidoreductases of the Trx system. In this study, the novel full-length cDNAs of LvTrx2 and LvTrxR were cloned from Litopenaeus vannamei. The ORFs of LvTrx2 and LvTrxR were 453 bp and 1785 bp, encoding polypeptides consisting of 150 and 596 amino acids. Sequence alignment analysis revealed that the amino acid sequence of LvTrx2 shared a high degree of identity (93%) with that of Penaeus chinensis, while in LvTrxR, it exhibited a similarity level of 95% with previously submitted Penaeus chinensis and Penaeus monodon sequences. Regarding tissue-specific expression patterns, LvTrx2 showed its highest expression levels in hepatopancreas and gill. For LvTrxR, the highest expression was observed in gill followed by hepatopancreas and intestine. During exposure to ammonia-N, there was a significant upregulation in the relative mRNA levels of LvTrx2 and LvTrxR in hepatopancreas and gill, with the peak values occurring at 24 h or 48 h of exposure. After LPS injection, the LvTrx2 and LvTrxR transcripts in hepatopancreas and gill had different upregulated levels. These findings suggest that LvTrx2 and LvTrxR play pivotal roles in enhancing stress resistance and bolstering antibacterial defense mechanisms in L. vannamei. To explore the roles, LvTrx2 expression was knocked down in vivo to verify the defense mechanism against 4-NP stress. LvTrx2 silencing in 4-NP-challenged shrimp could significantly induce the gene expression of antioxidant-related genes (except for LvTrxR) and aggravate the oxidative damage of lipids. This study suggests that the Trx system is involved in regulating the antioxidant processes, and LvTrx2 and LvTrxR play a vital role in defense responses against environmental stress. Full article

Wildfires are significant disturbances that reshape soil ecosystems, impacting soil properties, microbial communities, and enzyme activities. In Pinus tabulaeformis forests in northern China, the effects of wildfire on soil health, particularly on Actinobacteriota and enzymatic functions, remain poorly understood. This study investigates both the direct and indirect effects of fire severity on these factors and examines how fire-induced changes in soil properties mediate microbial and enzymatic responses. Our findings show that wildfire significantly alters soil chemical properties, including an increase in soil pH and a reduction in organic carbon and water content, particularly under high fire severities. These changes directly impact microbial communities, with Actinobacteriota showing resilience under light and moderate fire intensities but declining under high severity, especially in subsoil layers. Soil enzymes, such as urease and protease, played a crucial role in mitigating the negative impacts of fire on nutrient cycling. Their activity promoted nutrient availability, aiding ecosystem recovery, even as fire intensity reduced overall soil fertility. Structural Equation Modeling (SEM) further revealed that the relationships between fire severity, soil properties, Actinobacteriota, and enzyme activity are shaped by both direct thermal effects and complex indirect interactions mediated by changes in soil moisture and nutrient levels. This study underscores the importance of considering both direct fire effects and the mutual interactions between soil properties, microbial communities, and enzymatic activities in post-fire recovery. The findings highlight that while high-severity fires disrupt soil health and microbial dynamics, soil enzymes can help regulate these impacts by enhancing nutrient cycling and supporting ecosystem stability. These insights contribute to a better understanding of wildfire-induced soil degradation and provide actionable strategies for enhancing post-fire soil restoration and microbial management in fire-prone ecosystems. Full article

The uniform removal of the bran layer significantly enhances the nutritional and economic benefits of rice. However, the influence of parameter conditions on the uniformity of milling in the abrasive milling process remains unclear. This is not conducive to improving the quality of rice milling. In this study, the effects of rotational speed and filling volume on milling uniformity in abrasive milling were investigated by combining experimental methods and simulation. The results showed that the higher the rotational speed, the more uniform the milling. The higher the filling volume, the more non-uniform the milling. The main reason for the variation in milling uniformity is the axial and radial position exchange of the rice particles in the milling chamber. The more frequent the exchange, the higher the milling uniformity. Subsequently, the frequency of position exchange was quantitatively characterised using axial and radial exchange rates, respectively. The rotational speed and filling volume change the position exchange frequency by affecting the rotational kinetic energy of the rice particles and the degree of dense rice population, respectively. These findings are useful in promoting rice loss reduction and nutritional balance. Full article