Search Results (341)

The rainy season characteristics are directly modulated by atmospheric circulation and moisture transport dynamics. Focusing on the characteristics of the rainy season onset date (RSOD), this study aims to advance the understanding and prediction of climate change impacts on agricultural production and disaster mitigation strategies. Based on rainfall data from 66 meteorological stations in northeast China (NEC) from 1961 to 2020, this study determined the patterns of the RSOD in the region and established its mechanistic linkages with atmospheric circulation and water vapor transport mechanisms. This study identifies a climatic regime shift around 2000, with the RSOD transitioning from low to high interannual variability in NEC. Further analysis reveals a strong correlation between the RSOD and atmospheric circulation characteristics: cyclonic vorticity amplifies before the RSOD and dissipates afterward. Innovatively, this study reveals a significant transition in the water vapor transport paths during the early rainy season in NEC around 2000, shifting from eastern Mongolia–Sea of Japan to the northwestern Pacific region. Moreover, the advance or delay of the RSOD directly influences the water vapor transport intensity—an early (delayed) RSOD is associated with enhanced (weakened) water vapor transport. These findings provide a new perspective for predicting the RSOD in the context of climate change while providing critical theoretical underpinnings for optimizing agricultural strategies and enhancing disaster prevention protocols. Full article

Biogenic amines (BAs) are frequently detected in seafood products, wines, and fermented foods, and they pose potential risks to human health. The current study analyzed the concentrations of five common BAs in seafood, fermented food, and complementary food for infants and children (fish sausage, canned complementary food for infants containing fish and shrimp ingredients, and fish floss) in China and estimated the acute health risks of histamine (HIS) from fermented foods in Chinese consumers. Among all the samples analyzed, HIS exhibited the highest detection rate (51.9%), followed by PUT (50.1%), and the detection rate of TRY (12.5%) was the lowest. The total average concentration of the five BAs across major food categories revealed that fermented bean curd had the highest total concentration of BAs (816.8 mg/kg), followed by shrimp (383.2 mg/kg) and cheese (328.0 mg/kg). In contrast, samples of complementary food for infants and children contained the lowest concentrations of BAs; the total average concentration of the five BAs was 12.0 mg/kg. The point assessment results showed that acute dietary exposure to HIS was highest from cheese (76.2 mg/d), followed by fermented bean products (74.5 mg/d). Furthermore, the probability assessment indicated that the probability of acute health risks from exposure to HIS was 0.44% for fermented bean product consumers and 0.014% for cheese consumers, respectively. Thus, for the general consumer, the probability of acute health risks caused by HIS in seafood and fermented foods is low. However, individuals with high consumption of cheese and fermented bean products may need to be concerned. Full article

Infrared small target detection is crucial for military surveillance and autonomous driving. However, complex scenes and weak signal characteristics make the identification of such targets particularly difficult. This study proposes YOLO-SSFA, an enhanced You Only Look Once version 11 (YOLOv11) model with three modules: Scale-Sequence Feature Fusion (SSFF), LiteShiftHead detection head, and Noise Suppression Network (NSN). SSFF improves multi-scale feature representation through adaptive fusion; LiteShiftHead boosts efficiency via sparse convolution and dynamic integration; and NSN enhances localization accuracy by focusing on key regions. Experiments on the HIT-UAV and FLIR datasets show mAP50 scores of 94.9% and 85%, respectively. These findings showcase YOLO-SSFA’s strong potential for real-time deployment in challenging infrared environments. Full article

Conventional trenchless pipeline rehabilitation technologies are primarily designed for circular pipelines, with limited applicability to box culvert structures. Even when adapted, these methods often lead to significant reductions in the effective cross-sectional area and fail to enhance the structural load-bearing capacity due to geometric incompatibilities. To overcome these limitations, this study proposes a novel construction approach that employs prefabricated high-strength thin concrete segment liners for the reinforcement of underground box culverts. The feasibility of this method was validated through full-scale (1:1) experimental construction in a purpose-built test culvert, demonstrating rapid and efficient installation. A static stacking load test was subsequently conducted on the reinforced upper section of the culvert. Results indicate that the proposed reinforcement method effectively restores structural integrity and satisfies load-bearing and serviceability requirements, even after removal of the original roof slab. Additionally, a finite element analysis was performed to simulate the stacking load test conditions. The simulation revealed that variations in the mechanical properties of the grout between the existing structure and the new lining had minimal impact on the internal force distribution and deformation behavior of the prefabricated segments. The top segment consistently exhibited semi-rigid fixation behavior. This study offers a promising strategy for the rehabilitation of urban underground box culverts, achieving structural performance recovery while minimizing traffic disruption and enhancing construction efficiency. Full article

Fungal melanin plays a vital role in the survival, reproduction, infection, and environmental adaptation of plant pathogenic fungi. To develop innovative strategies for managing plant fungal diseases, comprehensive investigations into melanin are imperative. Such research is fundamental to elucidating the mechanistic basis of fungal pathogenesis and holds promise for the design of targeted interventions against melanin-mediated virulence determinants. This review systematically elaborates on the classification of fungal melanin in plant pathogens, provides a detailed analysis of the biosynthetic processes of 3,4-dihydroxyphenylalanine (DOPA) and 1,8-dihydroxynaphthalene melanin (DHN melanins), and reveals the catalytic functions and regulatory mechanisms of key enzymes within these pathways. Melanin modulates fungal virulence by influencing appressorial integrity and turgor pressure formation, thereby participating in the host infection process and the formation of overwintering sclerotia. Melanin provides stress resistance by protecting against extreme environmental factors, including UV radiation and high temperatures. It also has the capacity to absorb heavy metals, which increases pathogen survival under adverse conditions. Furthermore, the review also explores the mechanisms of action of melanin inhibitors that target plant pathogenic fungi, providing a theoretical foundation for developing efficient and environmentally friendly antifungal medications. The complex biosynthesis pathways and diverse biological functions of fungal melanin highlight its significant theoretical and practical importance for elucidating pathogenic mechanisms and formulating scientific control strategies. Full article

Tea has become one of the most popular drinks worldwide thanks to its pleasant sensory attributes and diverse health benefits. However, tannin-rich compositions have several negative effects and significantly impact the quality of tea beverages. Among various detannification methods, tannase treatment appears to be the most secure and environmentally friendly strategy. Although numerous microbial tannases have been identified and used in food processing, they are predominantly mesophilic with compromised heat tolerance, which limit their application in high-temperature tea extraction processing. Computer-assisted rational design and site-directed mutagenesis has emerged as a promising strategy in enzyme engineering to improve the thermostability of industrial enzymes. Nevertheless, relevant studies for tannase thermostability improvement remain lacking. In the present study, a novel thermophilic tannase called TanPL1 from marine fungus Penicillium longicatenatum strain SM102 was expressed in the food-grade host Yarrowia lipolytica. After purification and characterization, the thermostability of this enzyme was improved through site-directed mutagenesis guided by computer-aided rational design and molecular dynamics simulations. Then the thermostable mutant MuTanPL1 was applied in green tea processing for both polyphenol extraction and ester catechin hydrolysis. The tannase yield and specific activity values of 166.4 U/mL and 1059.3 U/mg, respectively, were achieved. The optimum pH and temperature of recombinant TanPL1 were determined to be 5.5 and 55 °C, respectively, and the enzyme exhibited high activity toward various gallic acid ester substrates. The site-directed mutagenesis method successfully generated a single-point mutant, MuTanPL1, with significantly enhanced thermostability and a higher optimum temperature of 60 °C. After 2 h of detannification by MuTanPL1, nearly all gallated catechins in green tea infusion were biotransformed. This resulted in a 202.4% and 12.1-fold increase in non-ester catechins and gallic acid levels, respectively. Meanwhile, the quality of the tea infusion was also markedly improved. Sensory evaluation and antioxidant activity assays revealed notable enhancements in these properties, while turbidity was reduced considerably. Additionally, the α-amylase inhibition activity of the tannase-treated tea infusion declined from 50.49% to 8.56%, revealing a significantly lower anti-nutritional effect. These findings suggest that the thermostable tannase MuTanPL1 holds strong application prospects in tea beverage processing. Full article

Background: Intercellular communication, facilitated by exosomes (Exos) derived from endothelial cells (ECs), significantly influences the regulation of angiogenesis. Leech extract significantly reduces ischemia–reperfusion injury, promotes angiogenesis, and improves neurological function in mice with stroke. However, further investigation is required to determine whether leech promotes angiogenesis through EC-Exo. Objective: This study aims to further explore whether leech regulates Exos to promote the establishment of collateral circulation in mice with ischemic stroke (IS) and the specific mechanisms involved. Methods: Here, we utilized an in vitro co-culture system comprising ECs and pericytes to investigate the impact of Leech-EC-Exo on enhancing the proliferation and migration of mouse brain microvascular pericytes (MBVPs). We further established an in vivo mouse model of middle cerebral artery occlusion/reperfusion (MCAO/R) to investigate the effects and underlying mechanisms of leech on collateral circulation establishment. Results: The findings demonstrated that leech significantly enhanced the in vitro cell migration number and migration number of pericytes. Therefore, it can also enhance the effect of EC-Exo on improving the infarct area and gait of mice, as well as modulating the HIFα-VEGF-DLL4-Notch1 signaling pathway to promote cerebral angiogenesis and facilitating the stable maturation of neovascularization in vivo. Conclusions: These results suggest that leech has the potential to enhance collateral circulation establishment, and its mechanism may involve the modulation of miRNA content in Exos and the promotion of signaling pathways associated with angiogenesis and vascular maturation. Full article

Background: Oral squamous cell carcinoma (OSCC), which accounts for over 90% of all oral malignancies, remains a major global health challenge due to its aggressive clinical course and poor prognosis. Periodontitis, a widespread chronic inflammatory condition affecting the supporting structures of the teeth, has increasingly been implicated as a potential risk factor for the development of various cancers. Emerging evidence suggests that microbial dysbiosis within the oral cavity may contribute to the creation of a pro-tumorigenic microenvironment, thereby promoting tumor initiation and progression. Nevertheless, the precise mechanisms linking periodontitis to OSCC, particularly through alterations in the oral microbiota, remain insufficiently understood. This article seeks to comprehensively analyze the association between periodontitis and OSCC and to elucidate the potential role of oral microbiota dysbiosis in mediating this relationship. Methods: In this study, a ligature-induced periodontitis model was established in C57BL/6J mice, and after two weeks, an OSCC model was introduced by the subcutaneous injection of SCC-7 cells to investigate the impact of periodontitis on OSCC progression. The effects of periodontitis on OSCC cell proliferation and invasion were assessed using scratch wound healing assays and CCK-8 proliferation assays. 16S rDNA high-throughput sequencing was conducted to profile the microbial communities present in the oral cavity and OSCC tissues, with particular emphasis on α-diversity indices (including Pielou’s evenness and Chao1 richness) and taxonomic composition at both the phylum and class levels. Furthermore, qPCR was utilized to assess the expression levels of cytokines in both periodontal and OSCC tissues, thereby elucidating the inflammatory milieu, potentially linking periodontitis to OSCC progression. Results: Our findings demonstrated that periodontitis significantly promoted OSCC growth and enhanced the invasive potential of OSCC cells. Microbial profiling revealed marked alterations in both the oral and OSCC microbiota, characterized by significant shifts in community composition and increased microbial diversity. Notably, these microbial changes exhibited consistent patterns between the oral cavity and the OSCC microenvironment, suggesting a potential mechanistic link between periodontitis-associated dysbiosis and OSCC progression. Consistently, qPCR analysis revealed elevated expression levels of IL-1β, IL-10, and IL-18 in both periodontal and OSCC tissues, providing evidence that the microbial alterations were accompanied by intensified inflammatory responses, which may contribute to OSCC progression. Conclusions: This study underscores the intricate interplay between periodontitis-induced microbial dysbiosis and the development of oral squamous cell carcinoma (OSCC). The findings suggest that periodontal inflammation, together with associated shifts in the oral microbiota, acts synergistically to drive OSCC progression. The elevated expression of cytokines further supports the role of a pro-inflammatory tumor microenvironment in mediating this interaction. These results offer important insights into the microbial and inflammatory mechanisms underlying the connection between periodontitis and OSCC, highlighting the critical role of maintaining periodontal health in the prevention and management of OSCC. Full article

The soil surrounding foundations is typically heterogeneous and anisotropic; however, existing studies for estimating the ultimate bearing capacity of foundations adjacent to slopes are predominantly applicable to isotropic and homogeneous soils. This study aims to investigate the ultimate bearing capacity of strip foundations adjacent to heterogeneous and anisotropic slopes within the framework of the Meyerhof theory. Considering the soil’s heterogeneity and anisotropy, a unilateral failure mode with varying base roughness is established. An analytical solution for the ultimate bearing capacity is derived using the limit equilibrium method, and the calculation steps are outlined through an iterative trial approach. The proposed formulation is validated by comparisons with theoretical solutions, numerical simulations and experimental data. Results indicate that the ultimate bearing capacity of foundations adjacent to slopes increases with an increase in the heterogeneity coefficient. In contrast, the ultimate bearing capacity decreases as the anisotropy coefficient increases, with a more significant reduction observed for higher cohesion soil. Moreover, the base roughness and the distance to slope crest also markedly influence the ultimate bearing capacity. Full article

Gelatin is a commonly used protein-based hydrogel. However, the thermo-reversible nature of gelatin makes it unstable at physiological and higher temperatures. Therefore, this study adopted phosphates and glutaminase transaminase (TG) to modify gelation and studied the effects of combining sodium hexametaphosphate (SHP) and TG on the structure and gel properties of TG-crosslinked gelatin. This study focused on the effects of different SHP concentrations (0, 0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8 mmol/L) on the water distribution, textural properties, rheological properties, and microstructure of the TG-crosslinked gelatin gels. Results showed that the free water content in the TG-crosslinked gelatin gel declined with the increasing SHP addition when the concentration of SHP was kept below 2.0 mmol/L. The gel of TG-crosslinked gelatin at the SHP concentration of 1.6 mmol/L exhibited the highest hardness (304.258 g), chewiness (366.916 g) and η₅₀. All the TG-crosslinked gelatin gels with SHP modification were non-Newtonian pseudoplastic fluids. The G′ and G″ of TG-crosslinked gelatin increased before the SHP concentration reached 1.6 mmol/L, and the TG-crosslinked gelatin with 1.6 mmol/L SHP exhibited the largest G″ and G′. The fluorescence intensity of TG-crosslinked gelatin with SHP concentration above 1.6 mmol/L decreased with the increasing SHP concentration. SHP modified the secondary structure of TG-crosslinked gelatin gels. The gel of TG-crosslinked gelatin with the SHP concentration of 1.6 mmol/L exhibited a porous, smooth, and dense network structure. This research provides references for modifying gelatin and the application of gels in the encapsulation of bioactive ingredients and probiotics. Full article

The female gametophyte is central to the reproductive success of flowering plants, with its development being tightly controlled by an intricate network of genes and signaling pathways. A deeper understanding of these regulatory mechanisms is essential for uncovering the complexities of plant growth and development. Recent studies have shed light on various aspects of female gametophyte development, highlighting the role of specific gene and signaling networks. Among these, the ERECTA family of leucine-rich repeat receptor-like kinase (RLK) in Arabidopsis thaliana has emerged as a key player, influencing multiple biological processes, particularly those governing reproductive development of the female gametophyte. This review focuses on the significant progress made in understanding the ERECTA family’s involvement in germline cell development, emphasizing its functional roles and signaling mechanisms in female gametophyte development. Full article

In mobile robot path planning, the traditional A* algorithm suffers from high path redundancy and poor smoothness, while the Dynamic Window Approach (DWA) tends to deviate from the global optimal path and has low efficiency in avoiding dynamic obstacles when integrated with global path planning. To address these issues, a smoothing optimised A*-guided DWA fusion algorithm (SOA-DWA) is proposed in this paper. Firstly, the A* algorithm was improved by introducing a path smoothing strategy and path pruning mechanism, generating a globally optimal path that complied with the vehicle kinematic constraints. Secondly, three sub-functions were introduced into the evaluation function of the DWA algorithm: the distance evaluation between the reference trajectory and the global path, the path direction evaluation, and the dynamic obstacle avoidance evaluation, to enhance the real-time performance of dynamic obstacle avoidance and the consistency of the global path. The SOA-DWA algorithm ensured that the mobile robot could effectively avoid obstacles in complex environments without deviating from the global optimal path. Thirdly, experimental results show that in a static environment, the path length and turning angle of the SOA-DWA algorithm are reduced by an average of 13.3% and 16.25%, respectively, compared with the traditional algorithm. In a dynamic environment, the path length and turning angle are reduced by an average of 10.5% and 14.5% compared to the traditional DWA algorithm, respectively, significantly improving the smoothness of the path and driving safety. Compared to the existing fusion algorithm, the SOA-DWA algorithm reduces the path length by an average of 10.1%, improves planning efficiency by an average of 42%, and effectively enhances obstacle avoidance efficiency. Finally, the effectiveness of the improved algorithm proposed in this paper was further verified by mobile robot experiments. Full article

In this paper, a wideband circularly polarized folded reflectarray antenna (CPFRA) based on a transmissive linear-to-circular polarization converter is proposed. The CPFRA consists of a primary reflector and a sub-reflector. To achieve broadband performance, a metasurface-based RA element on the primary reflector surface and a transmissive linear-to-circular polarization converter on the sub-reflector surface are applied. Moreover, the transmissive linear-to-circular polarization converter on the sub-reflector surface helps convert linear polarization to circular polarization. To verify the proposed CPFRA, a prototype is designed, fabricated, and tested. The measured results exhibit that the proposed CPFRA presents a 3 dB gain bandwidth of 27.4% and a 3 dB axial ratio bandwidth of 23%. The CPFRA achieves a peak gain of 21.2 dBi with an aperture efficiency of 27.2%. The proposed CPFRA is a promising candidate for millimeter-wave (mm-W) satellite communication applications because of its advantages of high gain, low cost, low profile, and broad bandwidth. Full article

During intensive aquaculture of Eriocheir sinensis (E. sinensis), wastewater containing feed additives, heavy metals, and antibiotics can cause water eutrophication and lead to the accumulation of complex pollutants in sediments. In this study, heavy metals and antibiotic resistance genes (ARGs) were analyzed for their distribution and accumulation patterns via ICP-OES and qPCR, and their correlations with bacterial communities in sediments from E. sinensis ponds were evaluated using co-occurrence network and redundancy analysis. Our results demonstrated that aquaculture activities significantly elevated the concentrations of heavy metals such as Cadmium (Cd) and Manganese (Mn) in the sediments, and Cd was identified as the dominant factor contributing to the increase in the potential ecological risk index (RI). The abundance of ARGs significantly increased, with sulfonamide resistance genes (sul1, sul2), β-lactam resistance genes (blaTEM), and integron-associated genes (intl1) showing the highest levels. Correlation and redundancy analyses showed that most ARGs were positively correlated with and linked to Proteobacteria, Bacteroidetes, and Dechloromonas as potential hosts. Positive correlations were generally observed among heavy metals, suggesting a common source, namely aquaculture wastewater, and some showed positive associations with Acidobacteria. This study provides a theoretical basis for further understanding the distribution, accumulation patterns, and coupling relationships of heavy metals and ARGs, as well as their relation and effects on bacterial communities in the sediment of E. sinensis ponds. Full article

Hydraulic fracturing significantly impacts water production. This makes it crucial to determine whether its effects on formation water production are beneficial or detrimental in complex reservoir stimulations. This paper gives the influence that acts on pore structure variations and irreducible water transformation by hydraulic fracturing; by using NMR and Micro-CT, pore-throat reconfiguration in core samples induced fracturing. Two main pore variation types were identified from CT images. To analyze the gas–water flow mechanisms in pre-fracturing and post-fracturing reservoir conditions, we tested quantifying changes in irreducible water transforms into movable water saturation by using a triaxial in situ flow system, thereby elucidating the impact of the hydraulic fracture on irreducible water saturation. The experiments demonstrate that pore structures are significantly modified in terms of connectivity and diameter through hydraulic fracturing. During damage zone formation, 12.4–19.2% of small pores coalesce into larger pores through integration of isolated spaces. This variation enhances fluid mobility, transforms 1.38–11.61% of irreducible water, and decreases starting pressure gradients by 1 MPa/100 m to 0.1 MPa/100 m. Modified pore structure leads to the iso-permeability point shifting toward higher water saturation. The gas-phase relative permeability at irreducible water saturation is two times as high as that of the matrix sample. Fractured zones show a 20–23% conversion efficiency of irreducible to movable water. In addition, based on the results of experimental data, hydraulic fracturing increased water production by 3607 to 9163 m³. However, this effect is only maintained during the first 3 to 6 months post-fracture. These results quantify the transformation of irreducible water into movable water in hydraulic fracturing. This study provides key performance indicators for gas reservoir applications. Full article