Search Results (408)

Periphytic algae, as representative aquatic epiphytic communities, play a vital role in the material cycling and energy flow in rivers. Through physiological processes such as photosynthetic carbon fixation and nutrient absorption, they perform essential ecological functions in water self-purification, maintenance of primary productivity, and microhabitat formation. This study investigates the interaction mechanisms between these highly flexible organisms and the hydrodynamic environment, thereby addressing the limitations of traditional hydraulic theories developed for rigid vegetation. By incorporating the coupled effects of biological flexibility and water flow, an innovative nonlinear resistance model with velocity-dependent response is developed. Building upon this model, a coupled governing equation that integrates water flow dynamics, periphytic algae morphology, and layered Reynolds stress is formulated. An analytical solution for the vertical velocity distribution is subsequently derived using analytical methods. Through Particle Image Velocimetry (PIV) measurements conducted under varying flow velocity conditions in an experimental tank, followed by comprehensive error analysis, the accuracy and applicability of the model were verified. The results demonstrate strong agreement between predicted and measured values, with the coefficient of determination R² greater than 0.94, thereby highlighting the model’s predictive capacity in capturing flow velocity distributions influenced by periphytic algae. The findings provide theoretical support for advancing the understanding of ecological hydrodynamics and establish mechanical and theoretical foundations for river water environment management and vegetation restoration. Future research will build upon the established nonlinear resistance model to investigate the dynamic coupling mechanisms between multi-species periphytic algae communities and turbulence-induced pulsations, aiming to enhance the predictive modelling of biotic–hydrodynamic feedback processes in aquatic ecosystems. Full article

Background: The metabolic dysfunction-associated steatotic liver disease (MASLD) represents an escalating global health concern, with effective treatments still lacking. Given its complex pathogenesis, multi-targeted strategies are highly desirable. Methods: This study reports the isolation of four flavone C-glycosides (FCGs) from Dianthus superbus L. and explores their potential in treating MASLD. The bioactivity and underlying mechanisms of FCGs were systematically evaluated by integrating network pharmacology, molecular docking, and zebrafish model validation. Results: Network pharmacology analysis revealed that FCGs may modulate multiple MASLD-related pathways, including lipid metabolism, insulin signaling, inflammation, and apoptosis. Molecular docking further confirmed strong binding affinities between FCGs and key protein targets involved in these pathways. In the zebrafish model of MASLD induced by egg yolk powder, FCGs administration markedly attenuated obesity, hepatic lipid accumulation, and liver tissue damage. Furthermore, FCGs improved lipid metabolism and restored locomotor function. Molecular analyses confirmed that FCGs upregulated PPARγ expression to promote lipid metabolism, restored insulin signaling by enhancing INSR, PI3K, and AKT expression, and suppressed inflammation by downregulating TNF, IL-6 and NF-κB. Additionally, FCGs inhibited hepatocyte apoptosis by elevating the BCL-2/BAX ratio. Conclusions: These findings highlight the multi-pathway regulatory effects of FCGs in MASLD, underscoring its potential as a novel therapeutic candidate for further preclinical development. Full article

The conveying hose is an important piece of equipment in the field of Marine engineering. Its spatial configuration and force conditions affect the normal operation of the Marine engineering system. This paper proposes a flexible, fully hose-based conveyance method for the field of deep-sea mining and mainly uses Orcaflex software to simulate and analyze the characteristics of the conveying hose in this system. This paper studies the influences of the top spacing, incoming flow direction, and placement and recovery processes on the configuration characteristics and force conditions of the hose. The conclusion drawn is that the conveying hose studied in this paper can maintain a good spatial configuration underwater and has a stable force condition. When the top spacing is 20 m, the transition of the curved section at the bottom of the hose is relatively smooth. The top tension of the hose has a good adaptability to the top spacing and the direction of the incoming flow. The conveying hose can stably complete the deployment and recovery operations. Full article

With the accelerated development of urban underground spaces, prefabricated tunnel linings have become a research focus due to their advantages in construction efficiency and cost effectiveness. However, issues such as stress concentration at joints and insufficient overall stability hinder their broader application. This study investigates a cut-and-cover prefabricated tunnel project in the Chongqing High-Tech Zone through scale model tests and numerical simulations to systematically compare the mechanical behaviors of cast-in situ linings and three-segment prefabricated linings under surrounding rock loads. The experimental results show that the ultimate bearing capacity of the prefabricated lining is 15.3% lower than that of the cast-in situ lining, with asymmetric failure modes and cracks concentrated near joint regions. Numerical simulations further reveal the influence of joint stiffness on structural performance: when the joint stiffness is 30 MN·m/rad, the bending moment of the segmented lining decreases by 37.7% compared to the cast-in situ lining, while displacement increments remain controllable. By optimising joint pre-tightening forces and stiffness parameters, prefabricated linings can achieve stability comparable to cast-in situ structures while retaining construction efficiency. This research provides theoretical and technical references for the design and construction of open-cut prefabricated tunnel linings. Full article

By measuring the transfer function of the single-mode multi-aperture vertical-cavity surface-emitting laser (SM MA VCSEL) transmitting over a long single-mode fiber at 850 nm, we confirm that the chirp of the SM MA VCSEL under study is dominated by transient chirp with an alpha value of −3.81 enabling a 19 GHz bandwidth over 10 km of single-mode fiber. The detailed measurement of the VCSEL with different bias currents also allows us to recover other key characteristics of the VCSEL, thereby enabling us to practically construct the optical eye diagrams that closely match the experimentally measured ones. The link-level transfer function can be obtained using an analytical equation including effects of modal dispersion and laser chirp–chromatic dispersion (CD) interaction for an MMF of a given length and bandwidth grade. The narrow linewidth and chirp characteristics of the SM MA VCSEL enable transmission performance that surpasses that of conventional MM VCSELs, achieving comparable transmission distances at moderate modal bandwidths for OM3 and OM4 fibers and significantly longer reaches when the modal bandwidth is higher. The transmission performance was also confirmed with the modeled eye diagrams using extracted VCSEL parameters. The chirp properties also provide sufficient bandwidth for SM MA VCSEL transmission over kilometer-scale lengths of single-mode fibers at a high data rate of 100G or above with sufficient optical power coupled into the fibers. Advanced transmission distances are possible over multimode and single-mode fibers versus chirp-free devices. Full article

Maize (Zea mays L.) seedlings are highly susceptible to low-temperature stress, which significantly impacts maize yield and quality. A zinc finger protein transcription factor (ZmZFP69) mutant and a control (B73) maize inbred line were subjected to low-temperature treatment, and changes in the phenotypic characteristics, hormone levels, and other indicators before and after the treatment were systematically identified. Subsequently, a combined RNA-seq and DAP-seq analysis was conducted to explore the influence of ZmZFP69 on the promoters of downstream genes. Finally, the proteins interacting with ZmZFP69 were examined using InterProDesign combined with BiFC and subcellular localization. The zmzfp69 homozygous mutant maize inbred line exhibited enhanced low-temperature tolerance compared to the control. RNA-seq and DAP-seq analyses revealed that ZmZFP69 binds to the ZmAOX2 gene promoter, significantly suppressing its expression. The interaction between ZmZFP69 and the downstream protein ZmBG6 was confirmed by InterProDesign, subcellular localization, and BiFC assays. ZmZFP69 negatively regulates maize seedling low-temperature tolerance by inhibiting ZmAOX2 expression and interacting with ZmBG6. Full article

Oxidative stress poses a challenge to in vitro embryo culture. As a flavonoid, galangin (GAL) has been shown to have antioxidant effects, but the effect and antioxidant capacity of GAL in the in vitro development of porcine parthenogenetic embryos are still unknown. In this study, we demonstrated that 1 µM GAL significantly increased the blastocyst rate, decreased the accumulation of intracellular reactive oxygen species (ROS), increased the glutathione (GSH) level, and enhanced mitochondrial function in early porcine embryos. Nuclear factor erythroid-2-related factor 2 (Nrf2) was identified as the target gene of GAL via network pharmacology, and the transcript levels of related antioxidant enzymes (HO-1, NQO1, SOD2, and CAT) were found to be increased. Since Nrf2 has seven domains, we constructed Nrf2 mutants lacking different domains in vitro. We found that GAL specifically binds to the Neh1 domain of Nrf2. Subsequent embryonic experiments demonstrated that the antioxidant effect of GAL was abolished after Nrf2 deletion. These results suggest that GAL can directly bind to Nrf2 to regulate the level of oxidative stress and improve mitochondrial function in embryos. Full article

C2H2 zinc finger proteins (C2H2-ZFPs) constitute one of the largest transcription factor families in plants, playing crucial roles in growth, development, and stress responses. Here, we performed a comprehensive genome-wide analysis of C2H2-ZFPs in foxtail millet (Setaria italica v2.0), identifying 67 members that were unevenly distributed across all nine chromosomes. Most SiC2H2 proteins were predicted to be alkaline, stable, and nuclear-localized, with the exception of SiC2H2-11 and SiC2H2-66, which were chloroplast-targeted. Phylogenetic analysis with Arabidopsis thaliana and Oryza sativa (rice) homologs classified these genes into seven distinct subfamilies, each containing the characteristic motif1 domain. Evolutionary studies revealed 14 segmental duplication events and strong syntenic conservation with Triticum aestivum (wheat, 163 orthologous pairs), suggesting conserved functions during evolution. Promoter analysis identified multiple cis-acting elements associated with light responsiveness, hormone signaling, and stress adaptation. Transcriptome profiling and qPCR validation in the YuGu 56 cultivar identified several stress-responsive candidates, including SiC2H2-35 and SiC2H2-58 (salt tolerance), as well as SiC2H2-23 (5.19-fold induction under salt stress) and SiC2H2-32 (5.47-fold induction under drought). This study provides some valuable insights into the C2H2-ZFP family in foxtail millet and highlights potential genetic markers for improving stress resilience through molecular breeding approaches. Full article

Vertical-cavity surface-emitting laser (VCSEL)-based transmission over multimode fiber (MMF) has achieved data rates of 100G per lane and is progressing towards 200G/lane, which demands more modal bandwidth from MMF to ensure adequate transmission reach. We address the needs of higher modal bandwidth from the point of view of engineering VCSEL launch conditions. We explore the options for using subsets of 10 standard-based launch conditions by analyzing the measured encircled fluxes from commercial VCSEL transceivers over two options. By utilizing experimentally measured MMF data, we demonstrated a significant improvement in modal bandwidth with these options. The launch conditions also impact the wavelength dependence of modal bandwidth for VCSELs operating at wavelengths longer than 850 nm. We conducted detailed Monte Carlo simulation of the wavelength dependence of modal bandwidth over MMFs. For one launch condition option using a smaller area, the modal bandwidths are improved over the effective modal bandwidth (EMB), and favor very high data rate transmission by allowing the use of a smaller area photodetector. Full article

Recently, research has increasingly focused on the introduction of non-precious metals and developing highly stable carriers to enhance catalyst performance. In this study, we successfully synthesized copper (Cu)-modified biochar catalysts utilizing a sequential approach involving enzymatic treatment, liquid impregnation, and activation processes, which effectively enhanced the dispersion and introduction efficiency of Cu onto the biochar, thereby reducing the requisite Cu loading while maintaining high catalytic activity. The experimental results showed that the toluene degradation of 10%Cu@BCL was three times higher than that of unmodified activated carbon (AC) at 290 °C. A more uniform distribution of Cu was obtained by the enzymatic and activation treatments, optimizing the catalyst’s structural properties and reducing the amount of Cu on the biochar. Moreover, the transformation between various oxidation states of Cu (from Cu⁰/Cu(I) to Cu(II)) facilitated the electron transfer during the degradation of toluene. To further understand the catalytic mechanisms, density functional theory (DFT) calculations were employed to elucidate the interactions between toluene molecules and the Cu-modified biochar surface. These findings reveal that the strategic modification of biochar as a carrier not only enhances the dispersion and stability of active metal species but contributes to improved catalytic performance, thereby enhancing its degradation efficiency for VOCs in high-temperature conditions. Full article

Background: Taste disorders in patients with type 2 diabetes mellitus (T2DM) have a negative impact on their quality of life and glycemic control, and treatment options are limited. Buzhong yiqi formula (BZYQF) improves T2DM symptoms but its effects on T2DM-induced taste disorders have not been sufficiently studied. Methods: Molecular docking was utilized to evaluate binding activity between the compounds in BZYQF and the sweet taste receptors (STRs). T2DM was induced in rats through the administration of high-fat diet and streptozotocin, and the rats were then treated with BZYQF for 8 weeks. Daily indicators and serum biochemical factors were monitored. Taste preferences for sweet, bitter, salty, and sour solutions were assessed using a two-bottle test. The morphology of lingual papillae and the numbers of taste buds were examined using HE staining. A high-glucose (HG) model of taste bud organoids was established to measure sucrose-evoked ATP release. The expression of signaling molecules in the sweet taste receptors (STRs) pathway was determined via RT-qPCR, Western blot, and immunofluorescence in lingual papillae and organoids. Results: A total of 508 compounds in BZYQF indicated good binding activity to T1R2, T1R3 or heterodimers of T1R2/T1R3, and 60 compounds had good binding activity to all three forms of STRs. BZYQF alleviated T2DM symptoms and improved taste perception for maltose (10 mM, 50 mM), quinine (0.03 mM, 0.1 mM), and citric acid (1 mM) solutions. BZYQF improved the morphological structure of lingual papillae and increased taste bud numbers in T2DM rats. BZYQF enhanced ATP release responses to sucrose solution in the taste bud organoids of the HG model. Gene expression determination showed that BZYQF upregulated the expression of signaling molecules in the STRs pathway (T1R2, T1R3, IP3R, α-gustducin, TRPM5) in the lingual papillae of the T2DM rats and in the taste bud organoids of the HG model. Conclusions: BZYQF alleviates T2DM-induced taste disorders by increasing the numbers of taste buds and upregulating STR signaling molecules, in which various compounds, especially flavonoids, exhibit a synergistic effect. Full article

The critical wind speed for stalk breaking is a direct and rapid method for evaluating stalk-breaking resistance. Maize lodging resistance is determined by the plant’s wind-induced stress and the stalk’s mechanical strength, yet the factors influencing plant stress remain unclear. This study analyzed the quantitative relationship between plant leaf area, weight, and stalk base torque by implementing different leaf-cutting and ear-removal treatments. The key factors affecting plant stress under varying wind speed conditions were identified. Results indicated that the critical wind speed for stalk breaking significantly increased following leaf cutting and ear removal. Under different wind speed conditions, stalk base torque exhibited a significantly negative correlation with the critical wind speed for stalk breaking, with the strongest correlation observed at U = 14.6 m s⁻¹. At this wind speed, every 1 m² increase in leaf area resulted in a torque increase of 6.7 N m and a decrease in critical wind speed for stalk breaking by 17.5 m s⁻¹. Similarly, every 1 kg increase in plant fresh weight led to an 8.1 N m torque increase and an 18.3 m s⁻¹ decrease in critical wind speed. Additionally, every 1 m increase in the height of the center of gravity resulted in a torque increase of 13.3 N m and a 22.9 m s⁻¹ reduction in critical wind speed. Regression analysis revealed that changes in critical wind speed for stalk breaking were primarily influenced by leaf area and plant fresh weight, which accounted for 80.6% of its variation. The effects of plant fresh weight and leaf area on torque varied under different wind speed conditions. In conclusion, maize leaf area, fresh weight, and center of gravity height influence the critical wind speed for stalk breaking by altering plant torque in a wind environment. Full article

This study investigated the preventive effects and mechanisms of Paeonia lactiflora pall stem and leaf extract (PLE) on oxidative stress-induced diarrhea in broilers, using a Diquat (DQ)-induced model. Results indicated that PLE significantly improved growth performance, increased average daily gain (ADG), reduced feed-to-gain ratio (F/G), and enhanced liver and kidney indices. PLE alleviated DQ-induced oxidative stress diarrhea by reducing the diarrhea rate by 63.84%, upregulating mRNA expression of MUC2, Claudin-1, ZO-1, and Occludin, and decreasing AST and ALT activities in serum. Additionally, PLE increased levels of CAT, SOD, GSH-Px, and GSH while reducing PCO and MDA levels in serum, intestine, and liver tissues. Furthermore, PLE increased acetic acid content and decreased propionic acid, butyric acid, and isobutyric acid contents. PLE also altered gut microbiota by up-regulated Bacteroidetes and Barnesiella and down-regulated Firmicutes and unclassified_o__Eubacteriales. Network pharmacology suggested that PLE acts via the PI3K-Akt-Nrf2 pathway, confirmed by up-regulated mRNA expression of PI3K, AKT, Nrf2, NQO1, and HO-1, and down-regulated Keap1 in intestinal and liver tissues. Correlation analysis revealed significant associations between Barnesiella and unclassified_o__Eubacteriales with short-chain fatty acids and PI3K-Akt-Nrf2 pathway-related genes. Thus, PLE prevents and alleviates oxidative stress-induced diarrhea in broilers by modulating the PI3K-Akt-Nrf2 pathway, regulating gut microbiota, and influencing short-chain fatty acids. Full article

With the increasing complexity of power systems, the monitoring data of UPFC submodules suffers from high missing rates due to sensor failures and environmental interference, significantly limiting equipment condition assessment and fault warning capabilities. To overcome the computational complexity, poor real-time performance, and limited generalization of existing methods like GRU-GAN and SOM-LSTM, this study proposes a hybrid framework combining Bayesian multiple imputation with a Support Vector Machine (SVM) for data repair. The framework first employs an adaptive Kalman filter to denoise raw data and remove outliers, followed by Bayesian multiple imputation that constructs posterior distributions using normal linear correlations between historical and operational data, generating optimized imputed values through arithmetic averaging. A kernel-based SVM with RBF and soft margin optimization is then applied for nonlinear calibration to enhance robustness and consistency in high-dimensional scenarios. Experimental validation focusing on capacitor voltage, current, and temperature parameters of UPFC submodules under a 50% missing data scenario demonstrates that the proposed method achieves an 18.7% average error reduction and approximately 30% computational efficiency improvement compared to single imputation and traditional multiple imputation approaches, significantly outperforming neural network models. This study confirms the effectiveness of integrating Bayesian statistics with machine learning for power data restoration, providing a high-precision and low-complexity solution for equipment condition monitoring in complex operational environments. Future research will explore dynamic weight optimization and extend the framework to multi-source heterogeneous data applications. Full article

Heterologous expression of the G231L variant of VioA into 16 strains of marine-derived Streptomyces, combined with bioactivity tracking, leads to the activation of seven antibiotic streptogramins (1–7) in Streptomyces sp. OUC20-O. Among these, compound 1, named linstreptogramin, is a new compound with an unusual linear streptogramin skeleton. The planar structure and stereochemistry of compound 1 were established based on extensive MS and NMR spectroscopic analyses, together with ECD calculations. In the antibacterial activity evaluation, compounds 1–4 showed significant growth inhibition against the multidrug-resistant Enterococcus faecium CCARM 5203 with MIC values of 0.2–1.6 µg/mL, which are comparable to the positive control vancomycin. Full article