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Abstract The peroxisome is a versatile organelle that performs diverse metabolic functions. PEX3, a critical regulator of the peroxisome, participates in various biological processes associated with the peroxisome. Whether PEX3 is involved in peroxisome-related redox homeostasis and myocardial regenerative repair remains elusive. We investigate that cardiomyocyte-specific PEX3 knockout (Pex3-KO) results in an imbalance of redox homeostasis and disrupts the endogenous proliferation/development at different times and spatial locations. Using Pex3-KO mice and myocardium-targeted intervention approaches, the effects of PEX3 on myocardial regenerative repair during both physiological and pathological stages are explored. Mechanistically, lipid metabolomics reveals that PEX3 promotes myocardial regenerative repair by affecting plasmalogen metabolism. Further, we find that PEX3-regulated plasmalogen activates the AKT/GSK3β signaling pathway via the plasma membrane localization of ITGB3. Our study indicates that PEX3 may represent a novel therapeutic target for myocardial regenerative repair following injury.

Scientific knowledge about the ancestral genome of core eudicot plant kingdom can potentially have profound impacts on both basic and applied research, including evolution, genetics, genomics, ecology, agriculture, forestry, and global climate. To investigate which plant conserves best the core eudicots common ancestor genome, we compared Arcto-Tertiary relict Nyssaceae and 30 other eudicot plant families. The genomes of Davidia involucrata (a known living fossil), Camptotheca acuminata and Nyssa sinensis, one per existent genus of Nyssaceae, were performed comparative genomic analysis. We found that Nyssaceae originated from a single Nyssaceae common tetraploidization event (NCT)– autotetraploidization 28–31 Mya after the core eudicot common hexaploidization (ECH). We identified Nyssaceae orthologous and paralogous genes, determined its chromosomal evolutionary trajectory, and reconstructed the Nyssaceae most recent ancestor genome. D. involucrata genome contained the entire seven paleochromosomes and 17 ECH-generated eudicot common ancestor chromosomes and was the slowest in mutation among the analyzed 42 species of 31 plant families. Combing both its high retention of paleochromosomes and its low mutation rate, D. involucrata provides the best case in conservation of the core eudicot paleogenome.

Background The regenerative capacity of the adult mammalian hearts is limited. Numerous studies have explored mechanisms of adult cardiomyocyte cell‐cycle withdrawal. This translational study evaluated the effects and underlying mechanism of rhCHK1 (recombinant human checkpoint kinase 1) on the survival and proliferation of cardiomyocyte and myocardial repair after ischemia/reperfusion injury in swine. Methods and Results Intramyocardial injection of rhCHK1 protein (1 mg/kg) encapsulated in hydrogel stimulated cardiomyocyte proliferation and reduced cardiac inflammation response at 3 days after ischemia/reperfusion injury, improved cardiac function and attenuated ventricular remodeling, and reduced the infarct area at 28 days after ischemia/reperfusion injury. Mechanistically, multiomics sequencing analysis demonstrated enrichment of glycolysis and mTOR (mammalian target of rapamycin) pathways after rhCHK1 treatment. Co‐Immunoprecipitation (Co‐IP) experiments and protein docking prediction showed that CHK1 (checkpoint kinase 1) directly bound to and activated the Serine 37 (S37) and Tyrosine 105 (Y105) sites of PKM2 (pyruvate kinase isoform M2) to promote metabolic reprogramming. We further constructed plasmids that knocked out different CHK1 and PKM2 amino acid domains and transfected them into Human Embryonic Kidney 293T (HEK293T) cells for CO‐IP experiments. Results showed that the 1–265 domain of CHK1 directly binds to the 157–400 amino acids of PKM2. Furthermore, hiPSC‐CM (human iPS cell‐derived cardiomyocyte) in vitro and in vivo experiments both demonstrated that CHK1 stimulated cardiomyocytes renewal and cardiac repair by activating PKM2 C‐domain‐mediated cardiac metabolic reprogramming. Conclusions This study demonstrates that the 1–265 amino acid domain of CHK1 binds to the 157–400 domain of PKM2 and activates PKM2‐mediated metabolic reprogramming to promote cardiomyocyte proliferation and myocardial repair after ischemia/reperfusion injury in adult pigs.

Bivalves are affected by various stressors, such as global warming and microplastics, in the marine environment. Microplastics are one of the most concerning pollutants worldwide, and high seawater temperatures caused by global warming influence the survival of marine organisms. However, little is known about the combined effects of elevated temperature and microplastics (MPs) on marine organisms, and most studies conducted in recent years have investigated the two factors, respectively. Thus, it is necessary to investigate the combined effects of elevated temperature and MP exposure on marine life. The Pacific oyster Crassostrea gigas is a widely distributed marine mollusk, and has very important economic value. The aim of the current study was to explore the toxic effects of elevated temperature and microplastic co-exposure on the hemocyte function, immune-related gene expression, and energy metabolism of C. gigas. In the current study, oysters were exposed to three levels of microplastics (no microplastics, 6 μm microplastics: SPS-MPs, and 50~60 μm microplastics: LPS-MPs) and two temperature levels (20 ℃ and 25 ℃) for 21 days, and the phagocytosis rate and reactive oxygen species (ROS) content of hemocytes, glycogen content in digestive glands, and immune-related gene expression in digestive glands and gills were examined on the 21st day. 2', 7'-Dichlorodihydrofluorescein diacetate and fluorescent microspheres were used to measure the ROS content and phagocytosis ratein hemocytes of C. gigas by flow cytometry, respectively. The glycogen content was measured using detection kits. Total RNA was isolated by TRIzol reagent, and the concentration was measured by Nanodrop. M-MLV Reverse Transcriptase was used for cDNA synthesis. The expressions of immune-related genes [inhibitor of NF-κB (IκB), p53, and heat shock protein 90 (HSP90)] were examined by quantitative real-time PCR in the digestive glands and gills of oysters from each treatment group. Two-way ANOVA was used to analyze the interactive effects of elevated temperature and microplastics on tested parameters of oysters using SPSS software. The results showed that exposure to SPS-MPs could elevate ROS content and reduce phagocytosis in hemocytes, but no significant interaction was found between elevated temperature and microplastic effects on ROS content and phagocytosis rate in hemocytes (P > 0.05). The 25 ℃+LPS-MPs exposure significantly decreased phagocytosis in hemocytes compared with single LPS-MPs and elevated temperature exposures (P < 0.05). Single SPS-MPs exposure significantly decreased phagocytosis in hemocytes compared with single LPS-MPs exposure (P < 0.05). In digestive glands, there was a significant interaction between elevated temperature and microplastics in glycogen content (P < 0.05), and the combined exposure could increase the glycogen content compared with other treatments. In digestive glands, the 25 ℃+LPS-MPs exposure significantly increased glycogen content compared with single elevated temperature and single LPS-MPs exposure (P < 0.05). In digestive glands and gills, there was a significant interaction between elevated temperature and microplastics in the expressions of HSP90, IκB, and p53 genes (P < 0.05). The 25 ℃+SPS-MPs exposure significantly upregulated the expression of HSP90, IκB, and p53 genes in the digestive glands of oysters compared with single SPS-MPs and single elevated temperature exposures (P < 0.05). The 25 ℃+SPS-MPs exposure significantly downregulated the expression of the HSP90 gene in the gills of oysters compared with single SPS-MPs exposure (P < 0.05). Single elevated temperature and single microplastics exposure significantly upregulated the expression of the IκB gene compared with the control in gills (P < 0.05). The combined exposure of elevated temperature and microplastics showed a significant antagonistic effect on the expression of the p53 gene in gills. Microplastics exposure downregulated p53 gene expression compared with the control at 20 ℃, while it upregulated p53 gene expression compared with single elevated temperature at 25 ℃. These results indicated that the p53 gene plays an important role in regulating the immune response in both digestive glands and gills. The interaction between elevated temperature and microplastics on the mRNA expression of HSP90 and IκB genes in digestive glands of C. gigas was size-dependent: A synergistic effect was found between SPS-MPs and elevated temperature, and an antagonistic effect was found between LPS-MPs and elevated temperature. A significant antagonistic effect was found between elevated temperature and microplastics on the mRNA expression of the IκB gene in gills, and the regulation pattern was different from that in the digestive glands, indicating that the regulation effect of the IκB gene was tissue-specific. In conclusion, the combined exposure of elevated temperature and microplastics can increase the glycogen content in the digestive glands of C. gigas, induce an immune response in digestive glands and gills, and trigger the oxidative stress response in hemocytes. Microplastics can cause stronger oxidative stress in hemocytes than elevated temperature. Moreover, a significant interactive effect was found between elevated temperature and microplastics on glycogen content in digestive glands and the expression of immune-related genes (HSP90, p53, and IκB) in digestive glands and gills. The results of this study provide valuable information for evaluating the toxic effects of microplastics on marine organisms under a global warming background.

Coptis chinensis Franch., also named Chinese goldthread is a member of Ranunculaceae in the order Ranunculales and represents an important lineage of early eudicots with traditional medicinal value. In our study, by using syntenic analysis combined with phylogenomic analysis of C. chinensis and four other representative genomes from basal and core eudicots, we confirmed that the WGD event in C. chinensis was shared by Aquilegia coerulea and Papaver somniferum L. and quickly occurred after Ranunculales diverged from other eudicots, likely a Ranunculales common tetraploidization (RCT). The synonymous nucleotide substitutions at synonymous sites distribution of syntenic blocks across these genomes showed that the evolutionary rate of the P. somniferum genome is faster than that of the C. chinensis genome by approximately 13.7%, possibly due to Papaveraceaes having an additional special tetraploidization event (PST). After Ks correction, the RCT dated to 115–130 million years ago (MYA), which was close to the divergence of Ranunculaceaes and Papaveraceaes approximately 115.45–130.51 MYA. Moreover, we identified homologous genes related to polyploidization and speciation and constructed multiple sequence alignments with different reference genomes. Notably, the event-related subgenomes in the basal genomes all showed genomic fractionation bias, suggesting a likely allopolyploid nature of the RCT, PST and T-Alpha and T-Beta events in Tetracentron sinense. In addition, we detected that the sixteen P450 subfamilies were markedly expanded in the genomes of Ranunculales, and most of them were related to the RCT and PST events. We constructed a new platform for Early Eudicot Comparative Genomic Research (http://www.cgrpoee.top/index.html) to store more information. In summary, our findings support the WGD of C. chinensis shared by Ranunculales, which is likely an allotetraploidization event. This present effort offered new insights into the evolution of key polyploidization events and the genes related to secondary metabolites during the diversification of early eudicots.

AIM: To report 5 cases with drug-induced bilateral acute ciliochoroidal effusion(DBACE)and myopic shift, with or without ocular hypertension(OHT), summarize patients' clinical characteristics and recovery process of DBACE, and investigate the possible pathophysiological mechanism.METHODS:A retrospective observational case study conducted from June 2017 to February 2021. The included patients were subjected to a series of ocular examinations listed as follows: 1)best corrected visual acuity; 2)intraocular pressure(IOP); 3)slit-lamp microscopy; 4)fundus photography; 5)ultrasound biomicroscopy(UBM); 6)subjective optometry; 7)axial length and anterior chamber depth. All patients were followed up every 2d until the diopters were completely restored to the state before the disease onset.RESULTS:In total, 5 patients aged 10-45 years old, including 3 female and 2 male patients, were enrolled in this study. All patients were bilaterally involved(5/5), and had myopic shift(5/5), of whom 3 patients had OHT(3/5). With the increase of age, myopic shift decreased, while OHT increased. Based on OHT, the dynamic aggravation process of DBACE was subdivided into 2 stages, stage 1(myopic shift without OHT)and stage 2(myopic shift with OHT). With the deterioration of DBACE, when myopic shift approached or exceeded the minimum amplitude of accommodation(MAA), IOP gradually rose, and DBACE progressed from stage 1 to stage 2. With the recovery of DBACE after discontinuing the suspicious drugs, DBACE in stage 2 first returned to stage 1, and then returned to normal.CONCLUSION:Pathophysiological mechanism of DBACE was subdivided into 2 stages, including stage 1(myopic shift without OHT)and stage 2(myopic shift with OHT). The transition between the two stages depends on the imbalance between myopic shift and MAA.

Societal Impact Statement Society anticipates a world in which more food and fiber must be produced at warmer temperatures, which, on the contrary, have greater constraints on the use of water and fertilizers. Tree legumes are often the climax vegetation on the semi‐arid and arid lands, covering ~25% of the planet, but the knowledge of their genomes is limited. A draft genome sequence for Prosopis alba, a salt and heat tolerant tree that is able to fix nitrogen under harsh conditions, yields new clues about its adaptations. Its rich genetic and ecological diversity makes Prosopis well‐suited to the investigation of gene functions important to its own greater utilization and/or the improvement of climate resilience of other crops. Summary In arid lands that comprise 41% of the Earth's surface and are growing, tree legumes are often the climax vegetation. Now found in much of arid America, Prosopis alba is a salt‐tolerant nitrogen‐fixing tree native to Argentina. We present a Prosopis alba genome assembly that is 707 Mb in size, comprising of 6087 contigs of up to 2,077,851 bp in length and of ~359.3 Mb (50.8%) being repetitive elements dominated (20.3%) by long terminal repeats (LTR) retrotransposons. Among a total of 57,572 coding sequences (CDS), 42,475 are putative protein coding genes with median length of 2748 bp. The Prosopis alba genome shares the legume‐common tetraploidy (LCT) but has not reduplicated, evolving 3.5% and 23.1% faster than Phaseolus vulgaris and Glycine max, respectively, since the LCT. The 50 most expanded gene families include many that are involved in ion homeostasis, perhaps related to drought and/or salt adaptation, together with photosynthetic genes carbonic anhydrase (CA), malate dehydrogenase (MDH) and malic enzyme and gene families involved in circadian clock systems, synthesis of brassinosteroids, auxin and gibberellin. Some expanded gene families include members showing molecular signatures of positive selection, as do numerous multi‐copy orthologous groups with features associated with pathogen resistance and single‐copy orthogroups related to drought and salt stress response, root and root hair development, nodulation, heavy metal detoxification and stay‐green habit. Coupling genomics‐based clues about possible causes of its striking physiological adaptations with rich diversity in ecological context offers means to further investigate functional roles of specific Prosopis genes/alleles.

The N-terminal sequences of proteins and their corresponding encoding sequences may play crucial roles in the heterologous expression. In this study, the secretory expression of alkaline pectin lyase APL in B. subtilis was investigated to explore the effects of the N-terminal 5–7 amino acid sequences of different signal peptides on the protein expression and secretion. It was identified for the first time that the first five amino acid sequences of the N-terminal of the signal peptide (SP-LipA) from Bacillus subtilis lipase A play an important role in promoting the expression of APL. Furthermore, it was revealed that SP-LipA resulted in higher secretory expression compared to other signal peptides in this study primarily due to its encoding of N-terminal amino acids with relatively higher transcription levels and its efficient secretion capacity. Based on this foundation, the recombinant strain constructed in this work achieved a new record for the highest extracellular yields of APL in B. subtilis, reaching 12,295 U/mL, which was 1.9-times higher than that expressed in the recombinant Escherichia coli strain previously reported. The novel theories uncovered in this study are expected to play significant roles in enhancing the expression of foreign proteins both inside and outside of cells.

Neutral pullulanases, having a good application prospect in trehalose production, showed a limited expression level. In order to address this issue, two approaches were utilized to enhance the yield of a new neutral pullulanase variant (PulA3E) in B. subtilis. One involved using multiple copies of genome integration to increase its expression level and fermentation stability. The other focused on enhancing the PulA-type atypical secretion pathway to further improve the secretory expression of PulA3E. Several strains with different numbers of genome integrations, ranging from one to four copies, were constructed. The four-copy genome integration strain PD showed the highest extracellular pullulanase activity. Additionally, the integration sites ytxE, ytrF, and trpP were selected based on their ability to enhance the PulA-type atypical secretion pathway. Furthermore, overexpressing the predicated regulatory genes comEA and yvbW of the PulA-type atypical secretion pathway in PD further improved its extracellular expression. Three-liter fermenter scale-up production of PD and PD-ARY yielded extracellular pullulanase activity of 1767.1 U/mL at 54 h and 2465.1 U/mL at 78 h, respectively. Finally, supplementing PulA3E with 40 U/g maltodextrin in the multi-enzyme catalyzed system resulted in the highest trehalose production of 166 g/L and the substrate conversion rate of 83%, indicating its potential for industrial application.

Industrial heavy metal-contaminated wastewater is one of the main water pollution problems. Adsorbents are a promising method for the removal of heavy metal contaminants. Herein, polyaspartic acid/carboxymethyl poplar sawdust hydrogels (PASP/CMPP) and ascorbic acid/carboxymethyl poplar sawdust hydrogels (VC/CMPP) were prepared by aqueous polymerization using alkalized poplar sawdust (CMPP) as the substrate and PASP and vitamin C (VC) as modifiers. The effective results, provided by the characterization analysis of SEM and BET, indicate that the surface of the PASP/CMPP hydrogel has a larger number of loose pores and a larger pore volume than the VC/CMPP hydrogel. The treatment effects of the two hydrogels on simulated wastewater containing Cd(II) were investigated by a batch of experiments. The results showed that PASP/CMPP had a better adsorption effect than VC/CMPP under the same adsorption conditions. Interestingly, the solid concentration effect was found in the process of sorption kinetics and sorption isotherms. The sorption kinetic curves of Cd(II) on PASP/CMPP were well-fitted by the quasi-second-order kinetics under different adsorbent concentrations. The adsorption conforms to Langmuir and Freundlich adsorption isotherm models. More importantly, PASP/CMPP composites are expected to be used as a new kind of environmental adsorbent for wastewater treatment. HIGHLIGHTS Hydrogels of PASP/CMPP were prepared.; The hydrogels of PASP/CMPP exhibit enhanced sorption capacities for Cd(II).; The hydrogels of PASP/CMPP are potential sorbents for wastewater treatment.; The solid concentration effect was found in the process of sorption kinetics and sorption isotherms.; The synthesis of PASP/CMPP hydrogels provides a win-win strategy.;

Vitrification is currently the primary choice worldwide for high-level nuclear waste immobilization. This study investigated the crystallization behaviors of glasses containing 24%(mass fraction) and 30% simulated high-level nuclear waste, respectively, under different temperatures. According to X-ray diffraction, Raman spectroscopy and scanning electronic microscopy results, dendritic powellite(CaMoO4) phase and string-like Zr-cerianite (ZrxCe1-xO2) are the main crystalline phases when the glasses are heat treated at 800 ℃, while a great amount of hollow hexagonal oxyapatite(Ca2Ln8(SiO4)6O2) phases are observed in addition when the glasses are heated at 950 ℃. The chemical durability test shows that the heat treatment decreases the total normalized leaching mass loss of glass by about 1/3, with main contributions from B, Na, Mo and Ca. The normalized leaching mass loss of the glasses after heat treatment at 950 ℃ is smaller than that after heat treatment at 800 ℃. It indicates that the heat treatment of glass for crystallization improves glass durability.

Abstract Background Gene conversion has an important effect on duplicate genes produced by polyploidization. Poplar (Populus trichocarpa) and willow (Salix brachista) are leading models and excellent green plants in the Salicaceae. Although much attention has been paid to the evolution of duplicated genes in poplar and willow, the role of conversion between duplicates generated from polyploidization remains poorly understood. Results Here, through genomic synteny analyses, we identified duplicate genes generated by the Salicaceae common tetraploidization (SCT) in the poplar and willow genomes. We estimated that at least 0.58% and 0.25% of poplar and willow duplicates were affected by whole-gene conversion after the poplar-willow divergence, with more (5.73% and 2.66%) affected by partial-gene conversion. Moreover, we found that the converted duplicated genes were unevenly distributed on each chromosome in the two genomes, and the well-preserved homoeologous chromosome regions may facilitate the conversion of duplicates. Notably, we found that conversion maintained the similarity of duplicates, likely contributing to the conservation of certain sequences, but is essentially accelerated the rate of evolution and increased species divergence. In addition, we found that converted duplicates tended to have more similar expression patterns than nonconverted duplicates. We found that genes associated with multigene families were preferentially converted. We also found that the genes encoding conserved structural domains associated with specific traits exhibited a high frequency of conversion. Conclusions Extensive conversion between duplicate genes generated from the SCT contributes to the diversification of the family Salicaceae and has had long-lasting effects on those genes with important biological functions.

In previous studies, researchers have used singing to treat respiratory function in patients with spinal cord injury. However, few studies have examined the way in which vocal training affects respiratory neural plasticity in patients with spinal cord injury. Vocal respiratory training (VRT) is a type of vocal muscle-related treatment that is often a component of music therapy (MT) and focuses on strengthening respiratory muscles and improving lung function. In this randomized controlled study, we analyzed the therapeutic effects of VRT on respiratory dysfunction at 3 months after cervical spinal cord injury. Of an initial group of 37 patients, 26 completed the music therapy intervention, which comprised five 30-minute sessions per week for 12 weeks. The intervention group (n = 13) received VRT training delivered by professional certified music therapists. The control group (n = 13) received respiratory physical therapy delivered by professional physical therapists. Compared with the control group, we observed a substantial increase in respiratory function in the intervention group after the 12-week intervention. Further, the nerve fiber bundles in the respiratory center in the medulla exhibited a trend towards increased diversification, with an increased number, path length, thickness, and density of nerve fiber bundles. These findings provide strong evidence for the effect of music therapeutic VRT on neural plasticity. This study was approved by the Ethics Committee of China Rehabilitation Research Center (approval No. 2020-013-1) on April 1, 2020, and was registered with the Chinese Clinical Trial Registry (registration No. ChiCTR2000037871) on September 2, 2020.

BackgroundCalcific aortic valve disease (CAVD) is a progressive disease resulting in severe calcific aortic stenosis (AS), and there is increasing interest in the discovery of novel biomarkers to identify patients with potential future calcific AS at an early stage. This study aimed to determine whether follistatin-like 1 (FSTL1) is associated with calcific AS events and its exact role in aortic valve calcification.MethodsA prospective observational cohort study involving 656 patients was performed to investigate the relationship between serum FSTL1 and calcific AS incidence during a follow-up of 5 years. Furthermore, we detected FSTL1 levels in valvular interstitial cells (VICs) from calcified valves and explored the effects of FSTL1 on VIC osteogenic differentiation in vitro as well as the signaling pathways involved.ResultsDuring a median follow-up of 5 years, lower FSTL1 levels were associated with a significantly higher risk of calcific AS events (log rank test, P = 0.007). In addition, Cox multivariable regression analyses verified the predictive value of FSTL1 after adjusting for both demographic features and laboratory confounders. Consistent with our results for serum, a lower concentration of FSTL1 was observed in calcified human valves (n = 11) and mainly colocalized with VICs. Recombinant human FSTL1 (rhFSTL1) stimulation inhibited calcium deposition, alkaline phosphatase (ALP) activity, and osteogenic gene expression partly through the downregulation of the ERK1/2 pathway.ConclusionTaken together, this study provides a strong rationale to consider FSTL1 as a potential therapeutic target for calcific AS.

Abstract Background Duplicated gene pairs produced by ancient polyploidy maintain high sequence similarity over a long period of time and may result from illegitimate recombination between homeologous chromosomes. The genomes of Asian cultivated rice Oryza sativa ssp. indica (XI) and Oryza sativa ssp. japonica (GJ) have recently been updated, providing new opportunities for investigating ongoing gene conversion events and their impact on genome evolution. Results Using comparative genomics and phylogenetic analyses, we evaluated gene conversion rates between duplicated genes produced by polyploidization 100 million years ago (mya) in GJ and XI. At least 5.19–5.77% of genes duplicated across the three rice genomes were affected by whole-gene conversion after the divergence of GJ and XI at ~ 0.4 mya, with more (7.77–9.53%) showing conversion of only portions of genes. Independently converted duplicates surviving in the genomes of different subspecies often use the same donor genes. The ongoing gene conversion frequency was higher near chromosome termini, with a single pair of homoeologous chromosomes, 11 and 12, in each rice genome being most affected. Notably, ongoing gene conversion has maintained similarity between very ancient duplicates, provided opportunities for further gene conversion, and accelerated rice divergence. Chromosome rearrangements after polyploidization are associated with ongoing gene conversion events, and they directly restrict recombination and inhibit duplicated gene conversion between homeologous regions. Furthermore, we found that the converted genes tended to have more similar expression patterns than nonconverted duplicates. Gene conversion affects biological functions associated with multiple genes, such as catalytic activity, implying opportunities for interaction among members of large gene families, such as NBS-LRR disease-resistance genes, contributing to the occurrence of the gene conversion. Conclusion Duplicated genes in rice subspecies generated by grass polyploidization ~ 100 mya remain affected by gene conversion at high frequency, with important implications for the divergence of rice subspecies.

In this work, an efficient numerical method is proposed for three-dimensional (3D) electromagnetic scattering from multiple coated targets buried under a two-dimensional dielectric rough surface. In the proposed method, the interior region of each coated target is regarded as an independent subregion. The field within each coated target is modeled by 3D vector finite element method (FEM). The multiple scattering interactions between the buried targets and between targets and rough surface are considered by the electric field integral equation and the Poggio–Miller–Chang–Harrington–Wu integral equations, respectively. The fields inside and outside the targets are coupled together via boundary conditions on the boundary of each target. To improve the calculation efficiency and reduce the memory requirement, the fast multipole technique is used in our method. The presented method is numerically validated by comparing it with method of moments and conventional FEM-boundary integral method (BIM). The results indicate that, compared with traditional FEM-BIM, our method has significant advantages in computational efficiency and memory requirements. [ABSTRACT FROM AUTHOR]

Rolling bearing is a key component of rotating machines, its working state directly affects the performance and safety of the whole equipment. Deep learning based on big data is a mainstream means of intelligent mechanical fault diagnosis. The key lies in enhancing fault feature and improving diagnosis accuracy. Different from the Convolution Neural Network (CNN) which relies on the convolution layer to extract the image features, the Vision Transformer (VIT) uses the multi-head attention mechanism to establish the relationship among the pixels in an image. In order to improve the accuracy of rolling bearing fault diagnosis, a new fault diagnosis method based on VIT is proposed. The vibration gray texture images to be input are divided into the patches according to the predetermined size and linearly mapped into input sequences, and the global image information is integrated through the self-attention mechanism to realize fault diagnosis. In order to enhance the expressiveness and generalization ability, the pooling layer is introduced into VIT. The tested results show that the fault diagnosis accuracy of VIT on the test set reaches 94.6%, and the corresponding classification indexes top-1 is 84.2% and top-5 is 95.0%. The accuracy of the new Pooling Vision Transformer (PIT) is 3.3% higher than that of the original VIT, which proves that the introduction to pooling layer can improve the image identification performance of VIT. [ABSTRACT FROM AUTHOR]