Search Results (60)

High-strength steel has high strength and low thermal conductivity, and its thin-walled parts are very susceptible to residual stress and deformation caused by cutting heat during the drilling process, which affects the machining accuracy and quality. High-strength steel thin-walled components are widely used in aerospace and other high-end sectors; however, systematic investigations into their temperature fields during drilling remain scarce, particularly regarding the evolution characteristics of the temperature field in thin-wall drilling and the quantitative relationship between drilling parameters and these temperature variations. This paper takes the thin-walled parts of AF1410 high-strength steel as the research object, designs a special fixture, and applies infrared thermography to measure the bottom surface temperature in the thin-walled drilling process in real time; this is carried out in order to study the characteristics of the temperature field during the thin-walled drilling process of high-strength steel, as well as the influence of the drilling dosage on the temperature field of the bottom surface. The experimental findings are as follows: in the process of thin-wall drilling of high-strength steel, the temperature field of the bottom surface of the workpiece shows an obvious temperature gradient distribution; before the formation of the drill cap, the highest temperature of the bottom surface of the workpiece is distributed in the central circular area corresponding to the extrusion of the transverse edge during the drilling process, and the highest temperature of the bottom surface can be approximated as the temperature of the extrusion friction zone between the top edge of the drill and the workpiece when the top edge of the drill bit drills to a position close to the bottom surface of the workpiece and increases with the increase in the drilling speed and the feed volume; during the process of drilling, the highest temperature of the bottom surface of the workpiece is approximated as the temperature of the top edge of the drill bit and the workpiece. The maximum temperature of the bottom surface of the workpiece in the drilling process increases nearly linearly with the drilling of the drill, and the slope of the maximum temperature increases nearly linearly with the increase in the drilling speed and feed, in which the influence of the feed on the slope of the maximum temperature increases is larger than that of the drilling speed. Full article

The four-level nested neutral point clamped (4L-NNPC) inverter has recently become a promising solution for renewable energy generation, e.g., wind and photovoltaic power. The NNPC inverter can stabilize the flying capacitor (FC) voltages of each bridge through redundant switch states (RSSs). This paper presents an improved three-layer sequential model predictive control (3LS-MPC) method for 4L-NNPCs. This method eliminates weighting factors and removes the switch states that generate high common-mode voltage (CMV). Before selecting the optimal vector, we disable certain switch states which affect the FC voltages, continuing to deviate from the desired value. Then, adopting a two-stage optimal vector selection method, we select the optimal sector based on six specific vectors and choose the optimal vector from the seven vectors in the optimal sector. The feasibility of this method was verified in Matlab/Simulink and the prototype. The experimental results show that compared with classical FCS-MPC, the proposed 3LS-MPC method reduces the common-mode voltage and has better harmonic quality and more stable FCs voltages. Full article

Format-compatible encryption can be used to ensure the security and privacy of JPEG images. Recently, a JPEG image encryption method proved to be secure against known plaintext attacks by employing an adaptive encryption key, which depends on the histogram of the number of non-zero alternating current coefficients (ACC) in Discrete Cosine Transform (DCT) blocks. However, this scheme has been demonstrated to be vulnerable to chosen-plaintext attacks (CPA) based on the run consistency of MCUs (RCM) between the original image and the encrypted image. In this paper, an improved CPA scheme is proposed. The method of incrementing run-length values instead of permutation is utilized to satisfy the uniqueness of run sequences of different minimum coded units (MCUs). The experimental results show that the proposed method can successfully recover the outlines of plaintext images from the encrypted images, even with lower-quality factors. Full article

Enhancing human well-being is a core priority of the Sustainable Development Goals. Understanding urban–rural well-being disparities is crucial for bridging gaps and improving social harmony. However, most existing studies focus on either urban or rural residents’ well-being, neglecting their disparities. This study quantified and compared the spatiotemporal patterns of the well-being of urban and rural residents in the Yangtze River Delta (YRD) urban agglomeration from 2000 to 2020 using the human development index (HDI). Results show the following: (1) Urban and rural well-being improved markedly from 2000 to 2020, with urban HDI increasing from 0.66 to 0.83 and rural HDI from 0.55 to 0.74. (2) Urban education and rural income inequalities were more pronounced, with the average Gini coefficients over 2000–2020 more than threefold and twofold those of urban and rural health, respectively. (3) Although disparities existed between urban and rural well-being, rural HDI had grown faster between 2000 and 2020, narrowing the urban–rural gap. From 2000 to 2020, the growth rate for rural HDI (34.55%) exceeded that for urban HDI (27.13%). To foster the shared urban and rural well-being, this study recommends diversifying rural industries, optimizing educational resources, and enhancing rural healthcare infrastructure in the YRD and beyond. Full article

Sclerotinia sclerotiorum is a devastating fungal pathogen that can colonize numerous crops. Despite its economic importance, the regulation of its development and pathogenicity remains poorly understood. From a forward genetic screen in S. sclerotiorum, six UV mutants were identified with loss-of-function mutations in SsATG1, SsATG2, SsATG4, SsATG5, SsATG9, and SsATG26. Functional validation through gene knockouts revealed that each ATG is essential for sclerotia formation, although the morphology of appressoria was not significantly altered in the mutants. Different levels of virulence attenuation were observed among these mutants. Autophagy, monitored using GFP-ATG8, showed dynamic activities during sclerotia development. These findings suggest that macroautophagy and pexophagy contribute to sclerotia maturation and virulence processes. Future work will reveal how autophagy controls target organelle or protein turnover to regulate these processes. Full article

Alzheimer’s disease (AD) is characterized by oxidative stress, amyloid-beta (Aβ) deposition, and tau hyperphosphorylation. While polysaccharides have demonstrated anti-AD effects, the properties of Cremastra appendiculata polysaccharides (CAPs) remain underexplored. This study evaluates the physicochemical properties, antioxidant activity, anti-AD effects, and underlying mechanisms of CAP in vitro and in Caenorhabditis elegans (C. elegans) AD models. CAP, containing 22.37% uronic acid, is stable below 270 °C and adopts a triple helix structure. Scanning electron microscopy (SEM) reveals an irregular layered architecture. In vitro, CAP exhibits significant antioxidant activity, protecting PC12 cells from Aβ-induced cytotoxicity. In C. elegans, CAP extends the lifespan in a concentration-dependent manner without affecting growth, alleviating tau-induced locomotor defects, reducing Aβ-induced paralysis and serotonin hypersensitivity, and decreasing Aβ deposition by 79.96% at 2.0 mg/mL. CAP enhances antioxidant capacity and heat resistance by reducing reactive oxygen species (ROS) levels and increasing glutathione S-transferase 4 (GST-4) and glutathione peroxidase (GSH-Px) activities. Additionally, CAP upregulates key genes in the insulin/insulin-like growth factor signaling pathway, including daf-16 and skn-1, along with their downstream targets (sod-3, ctl-1, gst-4, hsp-70). These findings suggest that CAP has potent antioxidant and anti-AD effects, alleviating Aβ- and tau-induced toxicity, and may serve as a promising therapeutic agent for Alzheimer’s disease. Full article

Wheat plays a crucial role in global food security. However, drought stress severely restricts its growth and development, and drought during the seedling stage significantly affects its organogenesis, thereby affecting yield. To study wheat drought tolerance mechanisms at the seedling stage and to explore drought tolerance gene resources, this study focused on the drought-tolerant wheat variety Bainong 207 and performed RNA-Seq and metabolome sequencing on leaves collected at the three-leaf stage under drought stress conditions. Drought stress significantly altered the expression of 12,930 genes and 2544 metabolites in wheat seedlings. Through bioinformatics methods such as O2PLS-DA, a gene–metabolite correlation network was constructed, and key regulatory genes within this network were subsequently identified. The results identified the important gene module MEbrown and metabolite module Meta6 and finally screened 20 transcription factors that are closely related to drought response. These transcription factors were predicted to be able to combine and regulate the expression of six key genes, which together help the variety to improve drought tolerance under drought stress conditions by regulating reactive oxygen species metabolism, maintaining intracellular redox homeostasis, promoting wax biosynthesis, enhancing the osmotic stress response, and regulating abscisic acid response. Full article

Magnoliaceae plants have high ornamental value, resulting in their widespread use in landscaping construction, and play a major role in the ecological functions of soil and water conservation. However, the landscape value of magnolias from the perspective of the water conservation capacity of the litter and soil layers is not yet fully understood; this restricts the popularization and application of Magnoliaceae plants in landscaping. In this study, we determined the characteristics of the litter thickness and mass, water absorption process, and soil water-holding capacity associated with five Magnoliaceae plants (Michelia shiluensis, M. crassipes, M. foveolata, M. maudiae, and M. odora). (1) The total litter thickness ranged from 2.29 to 5.58 cm, with M. crassipes achieving the highest value. The total litter mass for M. shiluensis (25.11 ± 2.58 t·ha⁻¹) was largely greater than that for the other magnolias. The mass of the un-decomposed litter (UL) layer was 1.31- to 3.82-fold larger than that of the semi-decomposed litter (SL). (2) The maximum water retention capacity (H_max) and effective water retention capacity (H_eff) of M. shiluensis were markedly larger than those of the other magnolias. (3) The W_max and W_eff of the UL layer were greater than those of the SL layer. (4) The soil bulk density varied from approximately 1.22 ± 0.08 g·cm⁻³ to 1.55 ± 0.08 g·cm⁻³, and the total soil porosity varied from 40.03 ± 3.44% to 46.42 ± 1.02%. The soil bulk density rose with an increasing soil depth, yet the total porosity was reduced. The soil water-holding capacity of the 0–30 cm soil layer varied from approximately 26.23 to 70.33 t·ha⁻¹, with soil near M. crassipes having the greatest water-holding capacity. The soil water infiltration recorded for M. crassipes was significantly higher than that of the other magnolias. The water conservation capacities associated with M. crassipes and M. shiluensis were the largest, which may suggest that these species are better at increasing rainfall interception, lightening splash erosion, and reducing surface runoff. Hence, we suggest that M. crassipes and M. shiluensis should be prioritized in landscaping applications. Full article

Broussonetia papyrifera is a deciduous tree with significant economic and medicinal value. It demonstrates notable physiological adaptability to mining areas with severe manganese contamination and is a pioneering species in the field of ecological restoration. Flavonoids are vital secondary metabolites that improve plant resilience to environmental stresses. In the study presented herein, immature and mature fruits of B. papyrifera grown in normal and high manganese environments were used as the test materials. B. papyrifera fruit was subjected to transcriptome sequencing via high-throughput sequencing technology to analyze its flavonoid metabolic pathways and related genes. Transcriptome sequencing identified a total of 46,072 unigenes, with an average length of 1248 bp and a percentage of Q30 bases ranging from 92.45 to 93.17%. Furthermore, 31,792 unigenes (69% of the total) were annotated using eight databases, including the GO and KEGG. Analysis of KEGG metabolic pathways and flavonoid content trends in B. papyrifera fruits revealed four unigenes with strong links to the flavonoid biosynthesis pathway under manganese stress: flavone 3-hydroxylase, flavonoids 3′,5′-O-methyltransferase, chalcone synthase, and flavonol synthase. These unigenes may play important roles in regulating flavonoid synthesis in B. papyrifera fruits under manganese stress. This study lays the groundwork for functional gene research in B. papyrifera. Full article

Detecting accurate 3D bounding boxes from LiDAR point clouds is crucial for autonomous driving. Recent studies have shown the superiority of the performance of multi-frame 3D detectors, yet eliminating the misalignment across frames and effectively aggregating spatiotemporal information are still challenging problems. In this paper, we present a novel flow-guided feature aggregation scheme for 3D object detection (FIFA3D) to align cross-frame information. FIFA3D first leverages optical flow with supervised signals to model the pixel-to-pixel correlations between sequential frames. Considering the sparse nature of bird’s-eye-view feature maps, an additional classification branch is adopted to provide explicit pixel-wise clues. Meanwhile, we utilize multi-scale feature maps and predict flow in a coarse-to-fine manner. With guidance from the estimated flow, historical features can be well aligned to the current situation, and a cascade fusion strategy is introduced to benefit the following detection. Extensive experiments show that FIFA3D surpasses the single-frame baseline with remarkable margins of $+10.8\%$ mAPH and $+6.8\%$ mAP on the Waymo and nuScenes validation datasets and performs well compared with state-of-the-art methods. Full article

Background: Brussels chicory affluent in phenolic acids could inhibit atherosclerosis; however, its effects on exercise performance and post-exercise recovery are unknown. We hypothesized that Brussels chicory could enhance exhaustive aerobic exercise performance and post-exercise recovery by promoting lactate oxidation. Methods: This is a single-blind, randomized, placebo-controlled two-way cross-over trial involving 32 untrained college students (men 18) who consumed either Brussels chicory juice (100 g of Brussels chicory containing ~130 mg phenolic acids and 180 mL fresh milk) or placebo (180 mL fresh milk) for 7 days with a 2-week washout period. On the 7th day, participants received a short-term, progressive workload, high-intensity, exhaustive aerobic exercise with the Bruce protocol. Time to exhaustion and blood lactate were evaluated after exercise. C2C12 myotubes were treated with Brussels chicory phenolic acids (0.625–10 μM) to evaluate these effects on lactate metabolism and lactate dehydrogenase A (LDHA) and B (LDHB), two enzymes responsible for lactate biosynthesis and oxidation, respectively. Results: Brussels chicory consumption increased time to exhaustion by 8.3% and 12.2% for men and women participants, respectively. This administration also promoted post-exercise recovery, evidenced by a reduction in blood lactate (14.5% for men and 10.6% for women). In C2C12 myotubes, Brussels chicory protocatechuic acid and caffeic acid did not affect LHDA-mediated lactate production, whereas these compounds dose-dependently promoted LDHB-mediated lactate oxidation through an enrichment of mitochondria LDHB. Conclusions: Dietary supplementation with Brussels chicory may enhance short-term, progressive workload, high-intensity, exhaustive aerobic exercise performance and post-exercise recovery in humans, possibly by accelerating LDHB-mediated lactate oxidation. Full article

Increased air pollution is driven by anthropogenic pollution emissions and climate change, which pose great challenges to environmental governance. Strengthening the monitoring of regional air quality levels and analyzing the causes of regional pollution is conducive to the management and sustainable development of the regional atmosphere. Functional data obtained on a wavelet basis were used in the fitting of air quality data of Fujian Province, and wavelet decomposition was performed to obtain low-frequency and high-frequency information. While the Fourier basis cannot adaptively adjust the time–frequency window, resulting in the loss of location information of special frequencies, the wavelet basis solves this problem. Functional analysis of variance was utilized for analyzing spatial differences in air pollution characteristics. Furthermore, the study established a multivariate functional linear regression model to explore the impact of meteorological factors and ozone precursor factors. The results indicated that the overall air quality was gradually improving in Fujian Province, but the concentration of ozone was progressively increasing. Air pollution in coastal areas was higher than that in inland areas. The p-values of the functional analysis of variance for energy values and crest values were less than 0.05. Moreover, the energy entropy and kurtosis values were greater than 0.05. There were significant differences of AQI in the fluctuation amplitude and variation characteristics of different cities. The total squared multiple correlation of regression model was above 50% on average. Ozone is currently the most serious pollution factor, mainly affected by wind speed, temperature, NO₂, and CO. In summer, it was principally influenced by VOCs. The findings of this study could act as a reference in exploring the time–frequency characteristics of air quality data and support of air pollution control. Full article

Currently, there is a lack of standardized diagnostic criteria for gestational diabetes mellitus (GDM), making it a subject of ongoing debate. The optimal diagnostic method and screening strategy for GDM remain contentious. In this review, we summarize the criteria and methods for diagnosing GDM, and perform a comparison between universal and selective screening strategies. Therefore, this review aims to highlight the following: (1) The most widely adopted criteria for GDM are those established by the International Association of Diabetes and Pregnancy Study Groups (IADPSG). (2) Evidence from cohort studies suggests that the one-step diagnostic method is associated with improved pregnancy outcomes and appears more cost-effective compared to the two-step method. (3) Universal screening is more cost-effective than selective screening, which may overlook a significant number of women with GDM. Additionally, various methods have been proposed for early pregnancy screening (before 14 weeks). Finally, an outlook is presented for the diagnosis of GDM, emphasizing the importance of large-scale randomized controlled trials (RCTs) to provide stronger evidence for future support. Full article

Betula pendula ‘Purple Rain’ is characterized by its purple leaves and has ornamental applications. A green mutant line NL, which was mutated by line NZ of B. pendula ‘Purple Rain’ during tissue culture, shows green leaves instead of the typical purple color of B. pendula ‘Purple Rain’. This study quantified the leaf color traits of NL and a normal B. pendula ‘Purple Rain’ line NZ, and uncovered differentially expressed genes involved in flavonoid biosynthesis pathway genes in NL through RNA-Seq analysis. Compared to NZ, reduced levels of six anthocyanins contained in NL were revealed via flavonoids-targeted metabolomics. Sequence mutations in transcription factors that could explain NL’s phenotype failed to be screened via whole-genome resequencing, suggesting an epigenetic basis for this variant. Therefore, a key gene, BpMYB113, was identified in NL via the combined analysis of small RNA sequencing, whole-genome methylation sequencing, and transcriptomics. In NL, this gene features a hyper CHH context methylation site and a lower transcription level compared to NZ, disrupting the expression of downstream genes in the phenylalanine metabolism pathway, and thereby reducing flavonoid biosynthesis. Our study elucidates an epigenetic mechanism underlying color variation in variegated trees, providing pivotal insights for the breeding and propagation of colored-leaf tree species. Full article

In the context of rapid urbanization in third-world countries, many cities adopt high-density development, effectively using land but limiting open space, especially for children, impacting their spatial rights. This study focused on the Dongcheng and Xicheng districts of Beijing. It employed methods such as variance inflation factor, multiple linear regression, spatial autocorrelation, and spatial econometric models to investigate the impact of various configuration factors on children’s satisfaction with outdoor activity space. The study also revealed the spillover effects of outdoor activity space configuration for children in high-density urban environments. The results showed that (1) children’s satisfaction was significantly influenced by the configuration elements. The variables that had the most significant impact on satisfaction were the number of outdoor spaces, facilities’ amusement, advertisements, and service management levels. (2) Using spatial econometric models, we determined that spatial dependency significantly enhances the model’s explanatory power. The quantity of outdoor space had the greatest effect on children’s outdoor activity space satisfaction, followed by facilities’ amusement and advertisement impact, and service management had the least impact, though all categories positively affected satisfaction. This study held significant value and importance in improving the rights of children in mega-cities in developing countries and promoting the physical and mental well-being of children. Full article