RESUMEN
A series of novel quinazoline-derived EGFR/HER-2 dual-target inhibitors were designed and synthesized by heterocyclic-containing tail approach. The inhibitory activities against four human epidermal growth factor receptor (HER) isozymes (EGFR, HER-2, HER-3 and HER-4) of all new compounds so designed were investigated in vitro. Compound 12k was found to be the most effective and rather selective dual-target inhibitor of EGFR and HER-2 with inhibitory constant (IC50) values of 6.15 and 9.78 nM, respectively, which was more potent than the clinical used agent Lapatinib (IC50 = 8.41 and 9.41 nM). Meanwhile, almost all compounds showed excellent antiproliferative activities against four cancer cell models (A549, NCI-H1975, SK-BR-3 and MCF-7) and low damage to healthy cells. Among them, compound 12k also exhibited the most prominent antitumor activity. Moreover, the hit compound 12k could bind to EGFR and HER-2 stably in molecular docking and dynamics studies. The following wound healing assay revealed that compound 12k could inhibit the migration of SK-BR-3 cells. Further studies found that compound 12k could arrest cell cycle in the G0/G1 phase and induce SK-BR-3 cells apoptosis. Notably, compound 12k could effectively inhibit breast cancer growth with little toxicity in the SK-BR-3 cell xenograft model. Taken together, in vitro and in vivo results disclosed that compound 12k had high drug potential as a dual-target inhibitor of EGFR/HER-2 to inhibit breast cancer growth.
RESUMEN
The paper presents a fault region identification method for the active distribution network (ADN) with limited PMU. First, PMU configuration and region division strategies are proposed based on the network topology. Next, the difference in three-phase current variations between the normal and fault regions of the ADN is analyzed. A multi-dimensional state monitoring matrix is built using the measured current data. The spectral norm ratio coefficient is constructed based on the 2-norm to lower the complexity of the multi-dimensional state monitoring matrix and quantify the difference in state changes before and after the fault occurs in each region. Then, the fault region is identified by combining each region's spectral norm ratio coefficient and the change of the current phase. Finally, an IEEE 33-node simulation model is created to simulate faults under different working conditions. According to the simulation results, the suggested approach is less impacted by fault type, neutral point grounding mode, and transition resistance. Furthermore, even if the communication does not match the rigorous synchronization requirements, the proposed method can still complete the fault identification of the distribution network correctly and has high robustness.
RESUMEN
This study focuses on the role of topoisomerases (TOPs) in sarcomas (SARCs), highlighting TOPs' influence on sarcoma prognosis through mRNA expression, genetic mutations, immune infiltration, and DNA methylation analysis using transcriptase sequencing and other techniques. The findings indicate that TOP gene mutations correlate with increased inflammation, immune cell infiltration, DNA repair abnormalities, and mitochondrial fusion genes alterations, all of which negatively affect sarcoma prognosis. Abnormal TOP expression may independently affect sarcoma patients' survival. Cutting-edge genomic tools such as Oncomine, gene expression profiling interactive analysis (GEPIA), and cBio Cancer Genomics Portal (cBioPortal) are utilized to explore the TOP gene family (TOP1/1MT/2A/2B/3A/3B) in soft-tissue sarcomas (STSs). This in-depth analysis reveals a notable upregulation of TOP mRNA in STS patients arcoss various SARC subtypes, French Federation Nationale des Centres de Lutte Contre le Cancer classification (FNCLCC) grades, and specific molecular profiles correlating with poorer clinical outcomes. Furthermore, this investigation identifies distinct patterns of immune cell infiltration, genetic mutations, and somatic copy number variations linked to TOP genes that inversely affect patient survival rates. These findings underscore the diagnostic and therapeutic relevance of the TOP gene suite in STSs.
Asunto(s)
Sarcoma , Humanos , Sarcoma/genética , Sarcoma/terapia , Pronóstico , ADN-Topoisomerasas/genética , ADN-Topoisomerasas/metabolismo , Mutación , Genómica , Regulación Neoplásica de la Expresión Génica , Neoplasias de los Tejidos Blandos/genética , Neoplasias de los Tejidos Blandos/terapia , Neoplasias de los Tejidos Blandos/mortalidad , Perfilación de la Expresión GénicaRESUMEN
In this paper, a new sensor is proposed to efficiently gather crucial information on corrosion phenomena and their progression within steel components. Fabricated with plastic optical fibers (POF), the sensor can detect corrosion-induced physical changes in the appearance of monitoring points within the steel material. Additionally, the new sensor incorporates an innovative structure that efficiently utilizes bi-directional optical transmission in the POF, simplifying the installation procedure and reducing the total cost of the POF cables by as much as 50% when monitoring multiple points. Furthermore, an extremely compact dummy sensor with the length of 5 mm and a diameter of 2.2 mm for corrosion-depth detection was introduced, and its functionality was validated through experiments. This paper outlines the concept and fundamental structure of the proposed sensor; analyzes the results of various experiments; and discusses its effectiveness, prospects, and economic advantages.
RESUMEN
Thioredoxins (TRXs) are central to redox regulation, modulating enzyme activities to adapt metabolism to environmental changes. Previous research emphasized mitochondrial and microsomal TRX o1 and h2 influence on mitochondrial metabolism, including photorespiration and the tricarboxylic acid (TCA) cycle. Our study aimed to compare TRX-based regulation circuits towards environmental cues mainly affecting photorespiration. Metabolite snapshots, phenotypes and CO2 assimilation were compared among single and multiple TRX mutants in the wild-type and the glycine decarboxylase T-protein knockdown (gldt1) background. Our analyses provided evidence for additive negative effects of combined TRX o1 and h2 deficiency on growth and photosynthesis. Especially metabolite accumulation patterns suggest a shared regulation mechanism mainly on mitochondrial dihydrolipoamide dehydrogenase (mtLPD1)-dependent pathways. Quantification of pyridine nucleotides, in conjunction with 13C-labelling approaches, and biochemical analysis of recombinant mtLPD1 supported this. It also revealed mtLPD1 inhibition by NADH, pointing at an additional measure to fine-tune it's activity. Collectively, we propose that lack of TRX o1 and h2 perturbs the mitochondrial redox state, which impacts on other pathways through shifts in the NADH/NAD+ ratio via mtLPD1. This regulation module might represent a node for simultaneous adjustments of photorespiration, the TCA cycle and branched chain amino acid degradation under fluctuating environmental conditions.
Asunto(s)
Dihidrolipoamida Deshidrogenasa , Mitocondrias , Tiorredoxinas , Dihidrolipoamida Deshidrogenasa/metabolismo , Dihidrolipoamida Deshidrogenasa/genética , Mitocondrias/metabolismo , Tiorredoxinas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/enzimología , Fotosíntesis , Oxidación-Reducción , NAD/metabolismo , Ambiente , Mutación , Dióxido de Carbono/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMEN
The timely and cost-effective identification of the onset of corrosion and its progress would be critical for effectively maintaining structural integrity. Consequently, a series of fundamental experiments were conducted to capture the corrosion process on a steel plate using a new type of plastic optical fiber (POF) sensor. Electrolytic corrosion experiments were performed on a 5 mm thick steel plate immersed in an aqueous solution. The POF sensor installed on the upper side of the plate and directed downward detected the upward progression of the corrosion zone that formed on the underside of the plate. The results showed that the POF sensors could detect the onset of the upward-progressing corrosion front as it passed the 1 and 2 mm marks related to the thickness of the corroded zone. The POF sensors were designed to optically identify corrosion; therefore, the data obtained by these sensors could be processed using a newly developed graphic application software for smartphones and also identified by the naked eye. This method offered an easy and cost-effective solution for verifying the corrosion state of structural components.
RESUMEN
Precipitation is a vital component of the global atmospheric and hydrological cycles and influencing the distribution of water resources. Even subtle changes in precipitation can significantly impact ecosystems, energy cycles, agricultural production, and food security. Therefore, understanding the changes in the precipitation structure under climate change is essential. The Qinghai-Tibet Plateau (QTP) is a region sensitive to global climate change and profoundly impacts the atmospheric water cycle in Asia and even globally, rendering it a hot topic in climate change research in recent years. Few studies have examined on the sub-daily scale precipitation structure over the QTP. In this paper, the characteristics of sub-daily precipitation on the QTP were systematically investigated from multiple perspectives, including the concentration index, skewness (the third standardized moment of a distribution), and kurtosis (the fourth standardized moment of a distribution). The results indicated that the frequency of moderate-intensity nighttime precipitation on the QTP generally increased, and the analysis of both the concentration index and kurtosis (skewness) suggested that extreme precipitation was more frequent in the southwestern foothills of the QTP. Furthermore, potential high-risk areas for natural disasters were identified on the QTP, and found that the southeastern part of the plateau constituted a potential hotspot area for flood disasters. Given the complexity of climate change, a comprehensive analysis of the spatiotemporal characteristics of diurnal and nighttime precipitation changes on the QTP could help reveal the regularity of precipitation changes. This has significant implications for forecasting, warning, disaster preparedness, and mitigation efforts on the QTP.
RESUMEN
Thiol-based redox regulation is a crucial posttranslational mechanism to acclimate plants to changing light availability. Here, we conducted a biotin switch-based redox proteomics study in Arabidopsis (Arabidopsis thaliana) to systematically investigate dynamics of thiol-redox networks in response to temporal changes in light availability and across genotypes lacking parts of the thioredoxin (Trx) or NADPH-Trx-reductase C (NTRC) systems in the chloroplast. Time-resolved dynamics revealed light led to marked decreases in the oxidation states of many chloroplast proteins with photosynthetic functions during the first 10â min, followed by their partial reoxidation after 2 to 6â h into the photoperiod. This involved f, m, and x-type Trx proteins showing similar light-induced reduction-oxidation dynamics, while NTRC, 2-Cys peroxiredoxins, and Trx y2 showed an opposing pattern, being more oxidized in light than dark. In Arabidopsis trxf1f2, trxm1m2, or ntrc mutants, most proteins showed increased oxidation states in the light compared to wild type, suggesting their light-dependent dynamics were related to NTRC/Trx networks. While NTRC deficiency had a strong influence in all light conditions, deficiencies in f- or m-type Trxs showed differential impacts on the thiol-redox proteome depending on the light environment, being higher in constant or fluctuating light, respectively. The results indicate plant redox proteomes are subject to dynamic changes in reductive and oxidative pathways to cooperatively fine-tune photosynthetic and metabolic processes in the light. The importance of the individual elements of the NTRC/Trx networks mediating these responses depend on the extent of light variability, with NTRC playing a crucial role to balance protein-redox states in rapidly fluctuating light.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Luz , Oxidación-Reducción , Proteoma , Compuestos de Sulfhidrilo , Tiorredoxinas , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/efectos de la radiación , Proteoma/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Tiorredoxinas/metabolismo , Tiorredoxinas/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Disulfuros/metabolismo , Fotosíntesis/efectos de la radiación , Proteómica/métodos , Reductasa de Tiorredoxina-Disulfuro/metabolismo , Reductasa de Tiorredoxina-Disulfuro/genética , Cloroplastos/metabolismoRESUMEN
The emergence of aquaculture modes has brought considerable changes to the aquaculture landscape and profoundly influenced environmental processes. However, there is limited research on nutrient cycling in emerging aquaculture modes. This study investigated the characteristics and mechanisms of sediment phosphorus (P) sorption-release in traditional earthen pond culture (TEP) and pond-tank culture mode (PTC), which represents novel aquaculture modes. The results showed that under higher nutrient load, the PTC did not show significant differences in nutrient concentration in water and sediments compared to TEP. Although there are no significant differences in overlying water P concentration between the modes throughout the entire aquaculture period, the trends of its variation over time are different, which significantly affected the P sorption-release characteristics of sediment. Additionally, correlation analysis suggested that calcium-bound P and hot NaOH-extractable organic P may affect the sorption-release characteristics of sediment as active P fractions. The change in redox condition caused by enzyme-mediated organic matter decomposition (such as protein and lipids) is also an important reason for sediment P release. However, the P fractions and organic matter content showed no significant differences between the two modes. Sediment microbial analysis showed that TEP exhibited a significant dominance of inorganic P-solubilizing bacteria, especially Actinobacteria and Bacilli classes. PTC had a higher proportion of organic P-solubilizing bacteria, primarily in the Bacteroidia class. The quantitative results of the key functional gene phoD in organic P decomposition also showed that the abundance in PTC was significantly higher than that in TEP. This suggested that microbial differences may be another reason for differences in P sorption-release behavior. This study revealed the differences in P sorption-release characteristics and mechanisms between the TEP and PTC, which holds positive implications for water quality and pollution management in novel aquaculture modes.
Asunto(s)
Fósforo , Estanques , Fósforo/análisis , Sedimentos Geológicos/análisis , Calidad del Agua , Bacterias , AcuiculturaRESUMEN
Owing to the limitations of the spatial arrangement of monitoring stations and time acquisition of satellite remote sensing images, the water quality monitoring of rivers, especially small- and medium-sized rivers, cannot be satisfied in terms of time and space continuity. In this study, we propose a standardization method for the camera images derived at different locations on different time considering the influences of light, shadows, reflections, ripples, leaves and so on. After this algorithm is established, an estimation algorithm based on the comprehensive appearance of water body is proposed, which has the potential of realising real-time, mobile, and continuous monitoring of water quality with low costs. The test results showed that the accuracy of the model was quite high compared to the results of the hydrological monitoring stations. Compared with the single-point detection of water quality monitoring stations, this method has advantages in terms of dynamic detection and small- andmedium-sized water body detection, which can serve as a supplement to traditional detection.
Asunto(s)
Monitoreo del Ambiente , Calidad del Agua , Monitoreo del Ambiente/métodos , Ríos , AlgoritmosRESUMEN
OBJECTIVE: Sound touch elastography (STE) and sound touch quantification (STQ) are novel imaging methods to evaluate tissue stiffness. This study aims to investigate renal stiffness in patients with chronic kidney disease (CKD) by STE and STQ, using renal biopsy as 'gold standard'. METHODS: Between 2019 January and 2022 June, 60 patients who underwent renal biopsy for proteinuria (cases) and 45 healthy volunteers (controls) at our hospital were included in this study. The maximum and mean elastic modulus (Emax, Emean) of region of interest in right kidney were measured by STE and STQ techniques. Biochemical profiles and renal biopsy findings were recorded. RESULTS: Both Emax and Emean measured by STE were significantly different between cases and controls. ROC analysis of STE measurements revealed using a cutoff of 13.53 kPa for Emax and 10.16 kPa for Emean, the area under the curve (AUC) to distinguish nephropathy from healthy was 0.718 and 0.744. Analysis of ROC for STQ measurements showed that using a cutoff value of 15.87 kPa for Emax and 9.95 kPa for Emean, the AUC for the nephropathy was 0.612 and 0.569. Emax and Emean values were significantly different among CKD patients with mild, moderate and severe pathological stage. The Emax value for STE was positively related to Scr, ß2-MG (r = 0.257, 0.292, p < 0.05). CONCLUSION: Both STE and STQ are non-invasive, feasible methods to quantitatively evaluate renal stiffness. STE is more effective than STQ in the diagnosis of CKD patients with proteinuria. CRITICAL RELEVANCE STATEMENT: Sound touch elastography is more effective than sound touch quantification in the diagnosis of chronic kidney disease patients with proteinuria. KEY POINTS: ⢠Emax and Emean measured by STE were different between cases and controls. ⢠Emax and Emean were different among CKD patients with different pathological stages. ⢠The Emax value for STE was positively related to serum creatinine, ß2-microglobulin.
RESUMEN
This study aimed to explore the potential mechanism by which sulfasalazine (SAS) inhibits esophageal cancer cell proliferation. A cell counting kit-8 (CCK-8) assay was used to detect the effect of SAS (0, 1, 2, and 4 mM) on the proliferation of TE-1 cells. Subsequently, TE-1 cells were divided into control group, SAS group, SAS + ferrostatin-1 (ferroptosis inhibitor) group, and SAS + Z-VAD (OH)-FMK (apoptosis inhibitor) group, and cell proliferation was measured using a CCK-8 assay. Real-time quantitative polymerase chain reaction and western blotting were used to determine the expression of solute carrier family member 7 11 (SLC7A11, also called xCT), glutathione peroxidase 4 (GPX4), and acyl-CoA synthase long-chain family member 4 (ACSL4) in TE-1 cells. Measurement of ferroptosis in TE-1 cells was achieved by flow cytometry. Compared with the control group (0 mM SAS), the proliferation of TE-1 cells was significantly inhibited by different concentrations of SAS for different time lengths, and 4 mM SAS treatment for 48 h could obtain the maximum inhibition rate (53.9%). In addition, SAS treatment caused a significant decrease in the mRNA and protein expression of xCT and GPX4, and a significant increase in ACSL4 expression in TE-1 cells treated with SAS. Flow cytometry results showed that the ferroptosis level was significantly increased after SAS treatment. However, the activation of ferroptosis by SAS was partially eliminated by treatment with ferrostatin-1 or Z-VAD (OH)-FMK. In conclusion, SAS inhibits the proliferation of esophageal carcinoma cells by activating the ferroptosis pathway.
Asunto(s)
Neoplasias Esofágicas , Ferroptosis , Humanos , Sulfasalazina/farmacología , Proliferación Celular , Neoplasias Esofágicas/tratamiento farmacológico , Proteínas Tirosina Quinasas ReceptorasRESUMEN
Plants contain three NADPH-thioredoxin reductases (NTR) located in the cytosol/mitochondria (NTRA/B) and the plastid (NTRC) with important metabolic functions. However, mutants deficient in all NTRs remained to be investigated. Here, we generated and characterised the triple Arabidopsis ntrabc mutant alongside with ntrc single and ntrab double mutants under different environmental conditions. Both ntrc and ntrabc mutants showed reduced growth and substantial metabolic alterations, especially in sink leaves and under high CO2 (HC), as compared to the wild type. However, ntrabc showed higher effective quantum yield of PSII under both constant and fluctuating light conditions, altered redox states of NADH/NAD+ and glutathione (GSH/GSSG) and lower potential quantum yield of PSII in sink leaves in ambient but not high CO2 concentrations, as compared to ntrc, suggesting a functional interaction between chloroplastic and extra-chloroplastic NTRs in photosynthesis regulation depending on leaf development and environmental conditions. Our results unveil a previously unknown role of the NTR system in regulating sink leaf metabolism and plant acclimation to HC, while it is not affecting full plant development, indicating that the lack of the NTR system can be compensated, at least to some extent, by other redox mechanisms.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , NADP/metabolismo , Dióxido de Carbono/metabolismo , Reductasa de Tiorredoxina-Disulfuro/genética , Reductasa de Tiorredoxina-Disulfuro/metabolismo , Arabidopsis/metabolismo , Fotosíntesis/fisiología , Cloroplastos/metabolismo , Oxidación-Reducción , Hojas de la Planta/metabolismo , Tiorredoxinas/metabolismo , AclimataciónRESUMEN
This paper presents the study of the residual deformation of functional gradient materials (FGMs) constructed by laser directed energy deposition (L-DED) and proposes a forward and reverse framework for inherent strain calibration, considering the effect of scan directions. First, the inherent strain and the corresponding residual deformation in the scanning strategies with the 0°, 45°, and 90° directions are calculated from the multi-scale model of the forward process, respectively. Then the inherent strain is calibrated inversely using the pattern search method based on the residual deformation of experiments by L-DED. The final inherent strain calibrated in the direction of 0° can be achieved through the rotation matrix and averaging. Finally, the final calibrated inherent strain is applied to the model of the rotational scanning strategy. The predicted trend of the residual deformation is highly consistent with the experiments in the verification stage. This work can provide a reference for the prediction of the residual deformation of FGMs.
RESUMEN
The dual oil circuit centrifugal fuel nozzle is made of martensitic stainless steel, which has complex morphological characteristics. The surface roughness characteristics of the fuel nozzle directly affect the degree of fuel atomization and the spray cone angle. The surface characterization of the fuel nozzle is investigated by the fractal analysis method. A sequence of images of an unheated treatment fuel nozzle and a heated treatment fuel nozzle are captured by the super-depth digital camera. The 3-D point cloud of the fuel nozzle is acquired by the shape from focus technique, and its three-dimensional (3-D) fractal dimensions are calculated and analyzed by the 3-D sandbox counting method. The proposed method can characterize the surface morphology well, including the standard metal processing surface and the fuel nozzle surface, and the experiments show that the 3-D surface fractal dimension is positively correlated with the surface roughness parameter. The 3-D surface fractal dimensions of the unheated treatment fuel nozzle were 2.6281, 2.8697, and 2.7620, compared with the heated treatment fuel nozzles dimensions of 2.3021, 2.5322, and 2.3327. Thus, the 3-D surface fractal dimension value of the unheated treatment is larger than that of the heated treatment and is sensitive to surface defects. This study indicates that the 3-D sandbox counting fractal dimension method is an effective method to evaluate the fuel nozzle surface and other metal processing surfaces.
RESUMEN
Introduction: Opioid use disorder is a cause for concern globally. This study aimed to optimize methadone dose adjustments using mixed modeling and machine learning. Methods: This retrospective study was conducted at Taichung Veterans General Hospital between January 1, 2019, and December 31, 2020. Overall, 40,530 daily dosing records and 1,508 urine opiate test results were collected from 96 patients with opioid use disorder. A two-stage approach was used to create a model of the optimized methadone dose. In Stage 1, mixed modeling was performed to analyze the association between methadone dose, age, sex, treatment duration, HIV positivity, referral source, urine opiate level, last methadone dose taken, treatment adherence, and likelihood of treatment discontinuation. In Stage 2, machine learning was performed to build a model for optimized methadone dose. Results: Likelihood of discontinuation was associated with reduced methadone doses (ß = 0.002, 95% CI = 0.000-0.081). Correlation analysis between the methadone dose determined by physicians and the optimized methadone dose showed a mean correlation coefficient of 0.995 ± 0.003, indicating that the difference between the methadone dose determined by physicians and that determined by the model was within the allowable range (p < 0.001). Conclusion: We developed a model for methadone dose adjustment in patients with opioid use disorders. By integrating urine opiate levels, treatment adherence, and likelihood of treatment discontinuation, the model could suggest automatic adjustment of the methadone dose, particularly when face-to-face encounters are impractical.
RESUMEN
Although existing studies suggest the relationship between ostracism and ingratiation, the knowledge about why and when ostracism promotes ingratiatory behaviors remains limited. Drawing from identity process theory, the current study examines the influence of ostracism on ingratiatory behaviors through the mediating role of self-identity threat on a daily timescale and the cross-level moderation of core self-evaluation. Through a diary study of 117 Chinese college students across 14 consecutive days, we found that daily ostracism had a positive indirect effect on daily ingratiatory behaviors through daily self-identity threat. Core self-evaluation of students weakened the indirect effect, such that only students with low core self-evaluation engaged in daily ingratiatory behaviors to cope with self-identity threat from ostracism. More importantly, supplemental analyses suggested that averaged daily ingratiatory behaviors were negatively related to perceived ostracism one week later. We discussed several theoretical and practical implications of these findings and proposed future research directions.
RESUMEN
To handle the problem of low detection accuracy and missed detection caused by dense detection objects, overlapping, and occlusions in the scenario of complex construction machinery swarm operations, this paper proposes a multi-object detection method based on the improved YOLOv4 model. Firstly, the K-means algorithm is used to initialize the anchor boxes to improve the learning efficiency of the depth features of construction machinery objects. Then, the pooling operation is replaced with dilated convolution to solve the problem that the pooling layer reduces the resolution of feature maps and causes a high missed detection rate. Finally, focus loss is introduced to optimize the loss function of YOLOv4 to improve the imbalance of positive and negative samples during the model training process. To verify the effectiveness of the above optimizations, the proposed method is verified on the Pytorch platform with a self-build dataset. The experimental results show that the mean average precision(mAP) of the improved YOLOv4 model for multi-object detection of construction machinery can reach 97.03%, which is 2.16% higher than that of the original YOLOv4 detection network. Meanwhile, the detection speed is 31.11 fps, and it is reduced by only 0.59 fps, still meeting the real-time requirements. The research lays a foundation for environment perception of construction machinery swarm operations and promotes the unmanned and intelligent development of construction machinery swarm operations.
RESUMEN
To overcome the difficulty of collecting the working resistance and working trajectory of a wheel loader, this paper constructs a statics model of the bucket working resistance and a kinematics model of the working trajectory in the shoveling process and analyzes the key parameters of measuring the working resistance and working trajectory. Based on this, a working resistance and working trajectory acquisition strategy is proposed. To verify the effectiveness of the acquisition strategy, the in-service operation data of fine sand and loose soil shoveled by the wheel loader are collected and analyzed. Then, the test-fitted working resistance and working trajectory are obtained, and the working trajectory is input into the RecurDyn-EDEM co-simulation model to obtain the simulation-fitted working resistance. Considering the complex working conditions of the wheel loader, it is difficult to obtain accurate working resistance, and the actual working resistance is also a relative value. Therefore, a strong correlation between the two curves indicates that the acquisition strategy of the wheel loader's working trajectory and working resistance proposed in this paper is feasible.
Asunto(s)
Suelo , Simulación por ComputadorRESUMEN
Saturated highlights on metal surfaces reduce the detection accuracy of fuel nozzles. In this paper, we propose an image inpainting method with a saturated highlight based on the statistics of similar patches used in prior segmentation of the subregion. The sequence image acquisition is based on the shape from focus in the five-axis platform. By our method, the focus measure (FM) operator and the window size are evaluated using the sharpness evaluation curve and calculating time. We observe that the detection accuracy is improved when the highlight area is filled by the highlight-free area within the same segmentation region. There are fewer deviation points in the three-dimensional (3D) point cloud that are extracted from the sequence images. The inlet circle and the outlet circle of the fuel nozzle are both detected by the two-dimensional (2D) Hough Transform (HT) method. Our experiments show that the method yields better results in 3D detection of the key parameters of fuel nozzles with the saturated highlight characteristics.