Search Results (2,771)

Over the past decade, an increasing number of functional microbial-like terpene synthases (MTPSLs) have been reported in non-seed plants. However, whether the traditional Chinese medicinal plant H. serrata harbors such enzymes and their corresponding functions remains unexplored. In this study, we mined the transcriptome of H. serrata and identified a microbial-like terpene synthase, HsMTPSL1, which produces multiple diterpene products. Following isolation and structural elucidation, seven distinct compounds were obtained, representing three skeletal types: spatane, prenylkelsoene-type, and biflorane. Among these, compound 7 is a novel biflorane diterpene. Structural analysis and subsequent mutagenesis revealed critical residues governing the formation of distinct skeletons, uncovering the multifunctional nature of this enzyme. Notably, the S224A mutation significantly enhanced the production of spatane diterpene compound 1 by 11.6-fold, demonstrating the potential for protein engineering to improve the yield of this bioactive marine-specific diterpene. Transcriptomic profiling revealed that HsMTPSL1 is highly expressed in sporangia, and co-expression analysis with cytochrome P450s identified the CYP781 subfamily as candidates potentially involved in the downstream modification of these skeletons. Collectively, we report the first MTPSL from H. serrata and characterize it as a multifunctional diterpene synthase. Through structure-guided mutagenesis, we uncovered the molecular basis of its functional versatility, with the S224A mutation providing a powerful tool for enhancing the yields of all three diterpene skeletons, thereby laying a foundation for future protein engineering and synthetic biology applications. Full article

Inflammation, as a basic pathological process, is critically implicated in the pathogenesis and progression of numerous diseases. Picrorhizae rhizoma is a type of traditional Chinese medicine with prominent anti-inflammatory effect. And picroside II, a representative iridoid compound, is the major bioactive constituent of Picrorhizae rhizoma. Over recent decades, picroside II has garnered extensive research interest owing to its remarkable pharmacological efficacy. Accumulating evidence has validated that picroside II exerts significant anti-inflammatory effects in the prevention and treatment of various systemic diseases. This review comprehensively summarizes and updates the latest research advances of picroside II, systematically elaborating its anti-inflammatory molecular mechanisms, pharmacokinetic profiles, and safety evaluation characteristics. The integrated data and analyses in this review aim to provide solid theoretical support, reliable evidence, and novel insights for the in-depth mechanism research, rational medicinal development, and future clinical translation and application of picroside II. Full article

This study investigates the synergistic mechanism between composite activators (NaOH and Na₂SiO₃ blend) and the microstructure–macroperformance relationship of foam concrete, focusing on the influence of different activator dosages on foam concrete stability, compressive strength, and drying shrinkage behavior. Experimental results indicate that excessively high activator dosages impair foam concrete stability, reduce compressive strength, and accelerate drying shrinkage. However, an appropriate amount of composite activator effectively improves the stability of freshly mixed foam concrete, significantly reducing settlement rates. During the hardening stage, it optimizes pore size distribution, promotes the formation of denser hydration products, and enhances the mechanical properties of the pore framework, thereby synergistically improving the mechanical performance of foam concrete. Full article

Accurate brain tumor segmentation in magnetic resonance imaging (MRI) is essential for diagnosis, treatment planning, and therapy monitoring. Conventional deep learning models often struggle with large variations in tumor shape, size, and contrast, as well as severe foreground–background imbalance. To address these challenges, this study presents Deep-MiSR, an enhanced encoder–decoder framework built upon DeepLabV3+ with a MobileNetV2 backbone, tailored for single-modality contrast-enhanced T1-weighted (T1CE) MRI segmentation. Three complementary components are integrated into the architecture: mixed depthwise convolution (MixConv) with heterogeneous kernels within the atrous spatial pyramid pooling module for multi-scale feature aggregation, a squeeze-and-excitation block for adaptive channel recalibration, and R-Drop regularization that enforces prediction consistency via symmetric Kullback–Leibler divergence. The model was evaluated on 3064 T1CE slices from 233 patients drawn from the publicly available Nanfang Hospital brain MRI dataset. Deep-MiSR achieved a Dice similarity coefficient of 0.9281, a mean intersection-over-union of 0.8738, a precision of 0.8839, and a 95th-percentile Hausdorff distance of 7.69 mm, demonstrating consistent improvements over both the DeepLabV3+ baseline and all prior methods evaluated on the same data. Ablation studies confirmed that each component contributes independently, with R-Drop providing the largest individual gain. These findings demonstrate that combining multi-scale convolution, channel attention, and consistency regularization constitutes an effective and computationally practical strategy for robust single-modality brain tumor segmentation. Full article

High-throughput plant phenotyping (HTPP) is increasingly limited by the mismatch between the need for field-relevant, fine-grained phenotypic information and the restricted capability of conventional observation platforms under complex agricultural conditions. Ground mobile robots are emerging as the key carrier for resolving this gap because they combine close-range sensing, autonomous mobility, and physical interaction within real field environments. In this paper, a structured scoping review is presented using a closed-loop perception–decision–action pipeline as the organizing principle. Within this framework, recent advances are synthesized from the perspectives of multimodal fusion, localization-aware sensing, motion planning, deep-learning-based phenotypic analysis, active observation, robotic intervention, and edge deployment. The review further clarifies the complementary roles of Unmanned Aerial Vehicles (UAVs), Unmanned Ground Vehicles (UGVs), and air–ground collaboration in multiscale phenotyping workflows. Beyond summarizing technologies, the article provides three concrete deliverables: a structured taxonomy of mobile phenotyping systems; comparative tables covering sensing modalities, localization/navigation methods, and AI models; and a research agenda linking technical progress to field deployability. The synthesis highlights four persistent bottlenecks, namely environmental generalization, annotation scarcity, limited standardization and reproducibility, and the gap between advanced models and agricultural edge hardware. Overall, ground robots are identified not merely as sensing platforms, but as the central system architecture for advancing mobile phenotyping toward autonomous, fine-grained, and field-deployable operation. Full article

Based on the stimulus–organism–response (S–O–R) framework, this study explored the psychological spillover mechanism through which tourism experiences in Museum Agglomeration Areas (MAAs) enhance city image and influence behavioral intentions. Structural equation modeling (SEM) based on survey data yielded several key findings. First, information visibility, content visibility, and the quality of amenities and the operational environment played critical roles in shaping tourists’ internal states, including perceived experiential value, affective response, immersion, and satisfaction. In addition, the social atmosphere emerged as an important factor in enriching these evaluations. Second, accessibility and connectivity were identified as factors that reduce friction along the visitor journey, thereby enhancing experiential continuity and immersion. Third, experiential value and immersion were found to be the primary mediators among the internal-state variables, transmitting the effects of environmental stimuli to city-level perceptions and behavioral intentions, such as revisit and recommendation intentions. These findings suggest that the competitiveness of MAAs lies not merely in spatial agglomeration itself but also in their ability to provide engaging and meaningful content, maintain safe and enjoyable operational environments, and develop integrated circulation and information systems. By conceptualizing MAAs as sites of district-scale tourism experiences, this study extends the application of the S–O–R framework to a multi-site urban cultural context and clarifies how differentiated internal states mediate the spillover from district experience to city-level perceptions and behavioral intentions. Rather than proposing a fundamentally new theoretical framework, the study offers a context-specific refinement of the organism layer and provides empirically grounded implications for design and operational strategies in culturally clustered urban districts. Full article

This study examines how perceived tourist comfort in museum agglomerations influences tourist satisfaction, museum agglomeration vitality, and the cultural sustainability of urban tourism, focusing on Jongno-gu, Seoul, based on the experiences of Chinese tourists. Moving beyond facility-centered evaluations of individual museums, the study conceptualizes museum agglomerations as continuous tourism environments shaped by movement, guidance, congestion, waiting, rest, and overall usability. Four latent constructs—Tourist Comfort, Tourist Satisfaction, Museum Agglomeration Vitality, and Cultural Sustainability of Urban Tourism—were tested using structural equation modeling. The results show that Tourist Comfort significantly enhances both Tourist Satisfaction and Museum Agglomeration Vitality, while Tourist Satisfaction further strengthens Museum Agglomeration Vitality. In addition, both Tourist Satisfaction and Museum Agglomeration Vitality have significant positive effects on the Cultural Sustainability of Urban Tourism. Tourist Comfort also exerts an indirect influence on cultural sustainability through the mediating pathways of Tourist Satisfaction and Museum Agglomeration Vitality. These findings contribute a demand-side, cluster-level explanation of how museum districts become experientially activated for tourists, while also indicating that the results should be interpreted as case-based evidence for Chinese tourists in Jongno-gu rather than as a universally generalizable model. Full article

This paper proposes an accelerated Riemannian conjugate gradient method based on the Barzilai-Borwein (BB) technique, termed ABBSRCG, for unconstrained optimization on Riemannian manifolds. Building upon classical Riemannian conjugate gradient frameworks, the method enhances step-size selection through a Wolfe-condition-informed strategy and incorporates a dynamic mechanism that adaptively adjusts the computed step length. The resulting algorithm achieves both high efficiency and numerical stability. Compared to conventional approaches such as the Fletcher-Reeves (FR)- type Riemannian conjugate gradient method, the Dai-Yuan (DY)- type Riemannian conjugate gradient method, ABBSRCG maintains the sufficient descent property regardless of whether a line search is used or not. Under mild assumptions, we establish the global convergence of ABBSRCG for u-strongly geodesically convex functions on Riemannian manifolds. Experiments on sphere and oblique manifolds show that ABBSRCG requires fewer iterations and achieves higher computational efficiency than existing Riemannian conjugate gradient methods, confirming its efficiency and reliability for large-scale Riemannian optimization problems. Full article

The evolutionary history and contemporary biogeography jointly shape the genetic architecture of marine species. This study investigates the phylogeny and population genetics of two closely related syngnathid fishes, Trachyrhamphus serratus and Trachyrhamphus longirostris. We report the first record of T. longirostris along the mainland coast of China, with samples collected from Yantai, Kenting, Zhanjiang, and Beihai. Population genetic analyses reveal genetic differentiation within T. longirostris, which exhibits low levels of genetic diversity across all sampled populations compared to T. serratus. The star-like haplotype network and significantly negative neutrality test values collectively indicate a recent population expansion event in T. longirostris. This study offers important insights into the evolutionary dynamics and biogeographic patterning of syngnathid fishes, with clear implications for their conservation and management. Full article

Elm (Ulmus pumila), an ecologically and economically valuable tree, exhibits significant tolerance to abiotic stress. However, the physiological and molecular mechanisms underlying its stress adaptabilities are largely unknown. Here, two elm salt-tolerant cultivars (ST-Y and ST-Q) and two salt-sensitive cultivars (SS-J and SS-JX) were identified in the 13 elm accessions collected from Shandong province, China via phenotypic salt tolerance screening. The key salt tolerance mechanisms were explored in ST-Y and SS-J via transcriptomic (RNA-Seq) assays, and subsequently validated in ST-Q and SS-JX via quantitative real-time polymerase chain reaction (RT-qPCR) analyses. Under salt treatment, ST-Y maintained leaf intactness and enhanced activation of antioxidant enzymes with a reduction in reactive oxygen species (ROS) accumulation, while SS-J suffered leaf defoliation and showed compromised antioxidant capacity with higher ROS levels. KEGG pathway analysis revealed that ST-Y leaves exhibited a unique enrichment of differentially expressed genes (DEGs) in the “oxidative phosphorylation (OXPHOS)” pathway after salt stress treatment. Both ST-Y and SS-J exhibited significant enrichment in the “metabolic pathway”, but the number of DEGs in the “arachidonic acid (AA) metabolism” pathway was much higher in ST-Y than in SS-J. Further RT-qPCR analysis verified the accuracy of the RNA-Seq data and revealed that genes related to the “OXPHOS” pathway were significantly up-regulated in ST-Y and ST-Q, but down-regulated in SS-J and SS-JX. Our results suggested that OXPHOS efficiency is critical to antioxidant capacity in elm salt tolerance, suggesting new avenues for forest tree improvement for climate change. Full article

While artemisinin and its derivatives demonstrate broad antitumor potential, the stereochemical influence on the bioactivity of higher-order artemisinin assemblies remains inadequately characterized. Herein, we report the synthesis, chromatographic separation, and structural elucidation of four stereoisomeric artemisinin trimers, followed by systematic evaluation of their antitumor efficacy against MCF-7 and MDA-MB-231 breast cancer cell lines. All trimers exhibited potent cytotoxicity against MCF-7 cells (IC₅₀ < 0.09 μM), with trimer 6a (β, β, β) demonstrating robust antitumor activity in both in vitro and in vivo xenograft models. Remarkably, pronounced stereochemistry-dependent activity emerged against MDA-MB-231 cells: 6a displayed approximately 100-fold greater potency than 6b (β, β, α) and 6.6-fold superiority over gemcitabine. Mechanistic investigations revealed that 6a downregulates Cyclin D1, CDK4, and CDK6 expression, thereby inducing G0/G1 phase cell cycle arrest. These findings underscore the pivotal role of stereochemical configuration in modulating artemisinin trimer bioactivity and provide rational guidance for structure-based design of artemisinin-derived anticancer therapeutics. Full article

Biopolymer-based packaging films possess outstanding performances and are being developed as the alternatives to traditional petroleum-based plastic packaging films with many non-ignorable shortcomings. In this study, chitosan, succinylated pullulan (SP), and berberine (BBR) were combined to fabricate novel biopolymer-based composite films (CSSPB) via the layer-by-layer assembly method. The effects of the incorporation of BBR on the physicochemical properties of the film were investigated. It was found that after BBR was added, the tensile strength (TS), elongation at break (EAB), hydrophobicity, and antioxidant capacities of the film were enhanced. The chemical bonding, crystalline properties, elemental composition, and thermal stability of the films were also characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA), respectively. The in vitro antifungal tests revealed the antifungal activities of the films with a relatively high BBR content against Colletotrichum gloeosporioides (CG). In the preservation experiments, the CSSPB films exhibited preservation effects on fresh-cut apples, which manifested as delaying browning, weight loss, an increase in the soluble solids content, and a decrease in hardness. The new CSSPB composite films were opined to hold application potential in the field of food packaging. Full article

Agricultural intelligent agent technology features autonomy in multimodal perception, scalability for cross-scenario collaboration and adaptability via closed-loop optimization, serving as a core technological pillar for industrial intelligent upgrading and refined production management. This paper systematically elucidates its technical essence and methodological framework, focusing on five key aspects: multimodal heterogeneous data perception and fusion, scenario-oriented knowledge modeling and dynamic memory, intelligent decision-making and planning, embodied artificial intelligence, and closed-loop feedback optimization. On this basis, the paper outlines its core agricultural applications in four domains: crop cultivation, efficient utilization of agricultural resources, intelligent upgrading of agricultural technologies and equipment, and collaborative governance of the entire agricultural industry chain. From an interdisciplinary “AI + Agriculture” perspective, the paper further analyzes its future development directions, aiming to provide insights for improving agricultural intelligent agent technologies and promoting their industrial application to accelerate agricultural intelligent transformation. This study constructs a three-dimensional integrated methodological framework encompassing technological analysis, application mapping and trend forecasting, systematically summarizes its agricultural application scenarios and technological evolution characteristics, enriches the theoretical system and methodological construction of agricultural intelligent agent research, and provides a reusable analytical paradigm for agricultural intelligent agent research and practice. Full article

In harsh marine environments, vessel energy storage systems (VESS) face elevated thermal runaway (TR) risk, yet practical early warning remains difficult because early voltage differences between TR high-risk cells and normal cells are often weak, warning thresholds vary across operating segments, and decisions relying on a single feature are prone to false or missed warnings. To overcome these difficulties, this study develops a four-part early warning strategy for TR high-risk cells in VESS. First, the original cell voltages are denoised through multiscale jump plus mode decomposition and Spearman correlation guided mode reconstruction to suppress irrelevant interference. Second, an improved Sigmoid nonlinear mapping is introduced to enhance subtle inter-cell voltage deviations and improve early separability. Third, sparse representation is used to construct a cell deviation score, and an adaptive threshold is employed to perform primary abnormal-cell screening under varying segment conditions. Finally, multidimensional mutual information value derived from voltage, temperature, and their rates of change is incorporated into a joint assessment methodology to further verify the abnormal state of flagged cells. Validation on 18 independent real operation cases comprising 2483 discharge segments shows that, across the evaluated TR high-risk cases, the shortest confirmed warning lead time achieved by the proposed strategy was 14 days. The proposed strategy also reduced false and missed warnings, outperformed the compared benchmark methods overall, and retained computational feasibility for onboard application in VESS. Full article

Apolygus lucorum, a phytozoophagous mirid bug, plays an important role in the species interactions within fruit tree and cotton ecosystems. Previous research has mainly focused on the phytophagous damage that it causes to crops, while its role as a predator of arthropods remains poorly understood. In this study, we systematically investigated the functional responses of A. lucorum to three crop pests: eggs of Helicoverpa armigera, nymphs of Aphis gossypii, and nymphs of Bemisia tabaci. The results show that the predatory behavior of A. lucorum towards all three prey species followed a Holling type II functional response model. Predatory performance varied significantly depending on prey species, developmental stage, and sex of the mirid. The theoretical maximum predation rate was highest for A. gossypii (833.33 individuals/day) and lowest for B. tabaci nymphs. Adult mirids and older nymphs (4th instar) exhibited higher predation rates than younger nymphs. Field-collected A. lucorum from Bt cotton fields were analyzed using molecular diagnostics, and the result confirmed natural predation on A. gossypii, which was consistent with observed pest occurrence patterns in the field. Overall, this study clarifies the prey selectivity and stage-dependent predatory strategies of A. lucorum, providing insights into its trophic flexibility as a facultative predator. These findings contribute to a more comprehensive understanding of its ecological role in agricultural ecosystems, but do not support its use as a biological control agent given its predominantly phytophagous nature and documented pest status. Full article