Dynamic look-ahead feedrate scheduling method based on sliding mode velocity control.

In the feedrate scheduling of complex curve direct interpolation, dynamic constraints such as axis acceleration and jerk are related to the actual state of the tool. Most existing methods convert dynamic constraints to velocity constraints at sampling points. However, it cannot guarantee the dynamic constraints are satisfied between sampling points. Addressing the issue, this paper proposes a dynamic look-ahead feedrate scheduling method based on sliding mode velocity control, which generates the motion command considering dynamic constraints in every interpolation cycle. To dynamically generate commands based on the current tool state, the acceleration and deceleration method based on sliding mode velocity control has been proposed, which can control tool state to transition to the command state with any initial state. To ensure sufficient distance for acceleration and deceleration, this paper uses braking distance to dynamically estimate the look-ahead distance. Then the minimum value within the look-ahead interval is selected as the command velocity for this scheduling cycle and the actual motion command is determined based on the dynamic constraints of each axis. Simulation and experiment results prove that compared with the existing method, this method effectively reduces the overshoot of dynamic constraints without significantly increasing the machining time. The analysis of real-time computation time has demonstrated the potential of the method proposed in this paper for real-time applications.

Associations between chronic obstructive pulmonary disease and ten common cancers: novel insights from Mendelian randomization analyses.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a significant global health issue, suspected to elevate the risk for various cancers. This study sought to discern whether COPD serves as a risk marker or a causative factor for prevalent cancers. METHODS: We employed univariable MR (UVMR) analyses to investigate the causal relationship between COPD and the top ten common cancers. Sensitivity analyses were performed to validate the main findings. Multivariable MR (MVMR) and two-step MR analyses were also conducted. False-discovery-rate (FDR) was used to correct multiple testing bias. RESULTS: The UVMR analysis demonstrated notable associations between COPD and lung cancer (odds ratio [OR] = 1.42, 95%CI 1.15-1.77, FDR = 6.37 × 10-3). This relationship extends to lung cancer subtypes such as squamous cell carcinoma (LUSC), adenocarcinoma (LUAD), and small cell lung cancer (SCLC). A tentative link was also identified between COPD and bladder cancer (OR = 1.53, 95%CI 1.03-2.28, FDR = 0.125). No significant associations were found between COPD and other types of cancer. The MVMR analysis that adjusted for smoking, alcohol drinking, and body mass index did not identify any significant causal relationships between COPD and either lung or bladder cancer. However, the two-step MR analysis indicates that COPD mediated 19.2% (95% CI 12.7-26.1%), 36.1% (24.9-33.2%), 35.9% (25.7-34.9%), and 35.5% (26.2-34.8%) of the association between smoking and overall lung cancer, as well as LUAD, LUSC, and SCLC, respectively. CONCLUSIONS: COPD appears to act more as a risk marker than a direct cause of prevalent cancers. Importantly, it partially mediates the connection between smoking and lung cancer, underscoring its role in lung cancer prevention strategies.

Mid-term Clinical Outcomes of "Light Bulb" Core Decompression with Arthroscopic Assistance in Peri-collapse Osteonecrosis of the Femoral Head: A Retrospective Comparative Study.

OBJECTIVE: Nontraumatic osteonecrosis of the femoral head (ONFH) is commonly encountered in orthopedics. Without early clinical intervention, most patients with peri-collapse of the ONFH will develop femoral head necrosis and eventually require hip replacement surgery. The aim of this study is to evaluate clinical outcomes in patients with ONFH who underwent "light bulb" core decompression (CD) with arthroscopic assistance and to compare them with the outcomes of those treated with traditional procedures. METHODS: A retrospective review of patients with Stage II and IIIA (Peri-collapse) radiographic findings based on the Association Research Circulation Osseous (ARCO) stage for ONFH who underwent "light bulb" CD with or without arthroscopic assistance by a single-surgeon team between March 2014 and December 2018 was performed. All patients were followed up for a minimum of 2 years. The visual analogue scale (VAS) pain score, Harris hip score (HHS), and radiological imaging were evaluated. The categorical parameters were analyzed by chi-square test and the continuous variables conforming to a normal distribution were analyzed by Student's t-test. RESULTS: The study included a total of 39 patients (18 and 21 patients in the with and without arthroscopic assistance groups, respectively), with a mean age of 40.3 years and a mean follow-up of 22.2 months. Overall, there was a better VAS score in the arthroscopic assistance group than in the control group (p < 0.05), There was a significant difference in HHS (80.1 ± 9.2 vs 75.1 ± 12.7) at the last follow-up (p < 0.05). The rate of good and excellent outcomes was 94%. Similarly, there was no significant difference in the total rate of complications or conversion to THA. CONCLUSION: With arthroscopic assistance, "light bulb" CD could be achieved via hip arthroscopy with less trauma, and it offered the opportunity for more precise evaluation and monitoring for therapy and yielded better VAS scores after surgery and better hip function outcomes at the last follow-up.

Efficacy and safety of high-frequency repetitive transcranial magnetic stimulation (rTMS) for migraine: a meta-analysis of randomized controlled trials.

OBJECTIVE: To assess the efficacy and safety of high-frequency repetitive transcranial magnetic stimulation in the prevention or treatment of migraine by conducting a pooled analysis of relevant randomized controlled trials. METHODS: The PubMed, Embase, Cochrane, OVID, SCOPUS, Web of Science, and clinicaltrials.gov databases were systematically searched for randomized controlled trials (RCTs) comparing high-frequency rTMS and sham stimulation for the prevention or treatment of migraine. A meta-analysis of relevant outcome measures was performed using RevMan 5.3 software. RESULTS: Eight RCTs with a total of 384 patients were included. A total of 23 patients dropped out, and thus, 361 patients were ultimately included for analysis. The high-frequency rTMS group had a lower frequency of attacks than the sham group (MD = - 5.10; 95% CI: - 8.10, - 2.09; P = 0.0009). The rTMS group has less intense headaches than the sham group (SMD = - 0.74; 95% CI - 1.04, - 0.44; P < 0.00001). High-frequency rTMS improved patient disability (SMD = - 0.45; 95% CI - 0.75, - 0.16; P = 0.003). High-frequency rTMS led to no advantage in reducing the number of abortive medications (MD = - 1.10; 95% CI - 3.28, 1.08; P = 0.32), but it increased the occurrence of adverse events (RR = 1.69; 95% CI 1.09, 2.64; P = 0.02). CONCLUSIONS: High-frequency rTMS reduces the frequency of attacks and headache intensity in migraine patients and improves the patient's disability, but it also increases adverse events.

Regulation effect of magnetic field combined with low temperature storage on postharvest quality and cell wall pectic-polysaccharide degradation of Clausena lansium (Lour.) Skeels.

This study investigated the regulation effect of magnetic field combined with low temperature storage on postharvest quality and cell wall pectic-polysaccharide degradation of wampee stored for 15 d at 4 °C and 15 °C. Results showed that magnetic field combined with low temperature storage reduced browning rate of fruit after 15 d storage, but its effect on weight loss rate and total soluble solids (TSS) did not surpass that of storage temperature. Interestingly, contents of flavonoid, total phenols and malondialdehyde (MDA) were also lowered at varying degrees by combined treatment. Furthermore, molecular weight distribution and monosaccharide compositions of cell wall pectic-polysaccharides were also affected, which resulted from the coordinated action of cell wall pectin-degrading enzymes. The activities of these enzymes during storage, including polygalacturonase (PG), pectin methylesterase (PME) and ß-galactosidase (ß-Gal) in treated wampee decreased. These findings suggested that magnetic field combined with low temperature storage was an effective technology and had great potential in preservation of postharvest wampee in future.

Constitutive Overexpression of an NB-ARC Gene from Wild Chinese Vitis quinquangularis in Arabidopsis thaliana Enhances Resistance to Phytopathogenic Oomycete and Bacteria.

Resistance (R) genes were used to recognize pathogen effectors directly or indirectly in plants and activate defense signal pathways. Most of these R proteins consist of a nucleotide-binding adaptor (NB-ARC) domain, a leucine-rich repeat (LRR) domain and some also have a coiled-coil (CC) structure. In this study, we cloned a gene which encodes the CC-NB-ARC-LRR R protein (VqCNL) from Chinese wild grapevine Vitis. quinquangularis accession 'Dan-2'. The transcript of VqCNL was obviously induced by inoculation with Plasmopara viticola and the salicylic acid (SA) treatment. The results of sequence analysis showed that the VqCNL gene contained a CC domain at the N-terminus, along with an NB-ARC and an LRR domain at the C-terminus. We transferred this gene into wildtype Arabidopsis and treated transgenic lines with Hyaloperonospora arabidopsidis (Hpa) and Pseudomonas syringae pv. tomato DC3000 (Pst DC3000); the results demonstrated that VqCNL promotes broad spectrum resistance to pathogens. Furthermore, qPCR analysis displayed that VqCNL may display a significant function in disease resistance via activating SA signaling pathways. In general, these conclusions primarily demonstrated that VqCNL enhances the disease resistance level in plants and contributes to future research of the R gene identification for grape breeding biotechnology.

Optimization of In Vitro Embryo Rescue and Development of a Kompetitive Allele-Specific PCR (KASP) Marker Related to Stenospermocarpic Seedlessness in Grape (Vitis vinifera L.).

Seedlessness is one of the highest valued agronomic traits in grapes. Embryo rescue in combination with marker-assisted selection have been widely applied in seedless grape breeding due to the advantages of increasing the ratio of seedless progenies and shortening the breeding cycle. However, the large number of deformed seedlings produced during embryo rescue and the lack of fast, efficient, and low-cost markers severely inhibit the process of seedless grape breeding. In this study, a total of eighty-three grape cultivars (51 seedless and 32 seeded) with diverse genetic backgrounds and two populations derived from embryo rescue, including 113 F1 hybrid individuals (60 seedless and 53 seeded), were utilized. We screened suitable media for converting malformed seedlings into normal seedlings, analyzed the association between the SNP in VviAGL11 and seeded/seedless phenotype, and developed a KASP marker related to stenospermocarpic seedlessness. Our results indicated that the transformation rate of 37.8% was obtained with MS medium supplemented with 2.0 mg·L-1 of 6-BA and 0.5 mg·L-1 of IBA. The presence of an A nucleotide allele at position chr18:26889437 was further confirmed to be fully associated with the stenospermocarpic seedlessness phenotype. The developed KASP marker, based on the verified SNP locus in VviAGL11, successfully distinguished the seedless and seeded genotypes with high precision and throughput. The results will contribute to enhancing the efficiency of embryo rescue and facilitate parent selection and early selection of seedless offspring with molecular markers, thereby accelerating the breeding process in seedless table grapes.

The Efficacy of Pretreatment 18F-FDG PET-CT-Based Deep Learning Network Structure to Predict Survival in Nasopharyngeal Carcinoma.

Background: Previous studies have shown that the 5-year survival rates of patients with nasopharyngeal carcinoma (NPC) were still not ideal despite great improvement in NPC treatments. To achieve individualized treatment of NPC, we have been looking for novel models to predict the prognosis of patients with NPC. The objective of this study was to use a novel deep learning network structural model to predict the prognosis of patients with NPC and to compare it with the traditional PET-CT model combining metabolic parameters and clinical factors. Methods: A total of 173 patients were admitted to 2 institutions between July 2014 and April 2020 for the retrospective study; each received a PET-CT scan before treatment. The least absolute shrinkage and selection operator (LASSO) was employed to select some features, including SUVpeak-P, T3, age, stage II, MTV-P, N1, stage III and pathological type, which were associated with overall survival (OS) of patients. We constructed 2 survival prediction models: an improved optimized adaptive multimodal task (a 3D Coordinate Attention Convolutional Autoencoder and an uncertainty-based jointly Optimizing Cox Model, CACA-UOCM for short) and a clinical model. The predictive power of these models was assessed using the Harrell Consistency Index (C index). Overall survival of patients with NPC was compared by Kaplan-Meier and Log-rank tests. Results: The results showed that CACA-UOCM model could estimate OS (C index, 0.779 for training, 0.774 for validation, and 0.819 for testing) and divide patients into low and high mortality risk groups, which were significantly associated with OS (P < .001). However, the C-index of the model based only on clinical variables was only 0.42. Conclusions: The deep learning network model based on 18F-FDG PET/CT can serve as a reliable and powerful predictive tool for NPC and provide therapeutic strategies for individual treatment.

Surface Feature Prediction for Laser Ablated 40Cr13 Stainless Steel Based on Extreme Learning Machine.

Determining an optimal combination of laser process parameters can significantly improve the efficiency and quality of 40Cr13 steel surface processing. In this study, two machine learning models (ELMSS and ELMPS) were proposed to predict the processing results of surface features to optimize process parameters. The prediction accuracies of the proposed models were always higher than those of traditional back propagation (BP) and radial basis function (RBF) neural networks, and the calculation time of the proposed models was significantly reduced. In comparison, the prediction accuracy ranking for ablation depth was ELMSS (92.6%), BP (89.8%), and RBF (89.6%), and for the ablation width, it was ELMSS (98.3%), BP (97.4%), and RBF (96.1%). The material removal rate was 92.4%, 91.1%, and 89.1% for ELMSS, BP, and RBF, respectively. Finally, the prediction accuracy ranking for surface roughness was 86.8%, 80.7%, and 79.5% for ELMPS, BP, and RBF, respectively. After optimization by the genetic algorithm, the prediction accuracies of the proposed models for the depth, width, material removal rate, and surface roughness reached 94.0%, 99.0%, 93.2%, and 91.2%, respectively. With the support of ELMSS and ELMPS, the results of the surface features can be predicted before machining and the appropriate process parameters can be selected in advance.

Regulation mechanism of magnetic field on pectinase and its preliminary application in postharvest sapodilla (Manilkara zapota).

In this study, regulation mechanism of magnetic field on pectinase was investigated and it was preliminarily applied in postharvest sapodilla. Results indicated pectinase activity decreased by 44 % when treated by magnetic field (3 mT, 0.5 h) with kinetic parameters Vmax/Km decreasing from 0.799 to 0.366 min. The optimal temperature (48 °C) and pH (4.8) of pectinase was not altered by magnetic field but Ca2+ at 0.05 mol/L strengthened its regulation effect. Ultraviolet and fluorescence spectra suggested tyrosine and tryptophan residues in treated pectinase became more hydrophobic while opposite in phenylalanine. CO, CNH, COO- groups in pectinase were also influenced, resulting in decreased ß-sheet (from 53 % to 49 %), increased random coil (from 20 % to 22 %) and ß-turn content (from 27 % to 29 %). More importantly, the firmness of treated sapodilla remained 45 % of maximum at 12 days' storage. Our findings provided new insights to illustrate the role of magnetic field in fruit preservation.

Object Detection Based on Roadside LiDAR for Cooperative Driving Automation: A Review.

Light Detection and Ranging (LiDAR) technology has the advantages of high detection accuracy, a wide range of perception, and not being affected by light. The 3D LiDAR is placed at the commanding height of the traffic scene, the overall situation can be grasped from the perspective of top view, and the trajectory of each object in the traffic scene can be accurately perceived in real time, and then the object information can be distributed to the surrounding vehicles or other roadside LiDAR through advanced wireless communication equipment, which can significantly improve the local perception ability of an autonomous vehicle. This paper first describes the characteristics of roadside LiDAR and the challenges of object detection and then reviews in detail the current methods of object detection based on a single roadside LiDAR and multi-LiDAR cooperatives. Then, some studies for roadside LiDAR perception in adverse weather and datasets released in recent years are introduced. Finally, some current open challenges and future works for roadside LiDAR perception are discussed. To the best of our knowledge, this is the first work to systematically study roadside LiDAR perception methods and datasets. It has an important guiding role in further promoting the research of roadside LiDAR perception for practical applications.

Depth Model and 5-Axis Variable-Angle Laser Engraving Experiment Based on the Energy Conservation Principle.

To ensure the consistency of laser engraving depth in chemical milling, the precise control of 5-axis variable-angle laser engraving was the focus of research. Based on the energy conservation principle, the depth model of 5-axis variable-angle laser engraving is established, and the relationships among the laser engraving depth, laser power, scanning velocity, and beam axis angle are proposed. A depth-constraint real-time adaptive control method of laser power is proposed considering the variable scanning velocity and beam axis angles. The depth model parameters are identified by an orthogonal experiment, and a variable-angle laser engraving experiment with adaptive control of laser power is carried out. The coefficient of determination of the proposed depth model is 0.977, which means that the engraving depth model established in this paper predicts the engraving depth effectively and reliably. The depth-constraint adaptive control method of laser power obtains stable and uniform machining results under abrupt changes in scanning velocity and beam axis angles.

Palladium-catalyzed interannular C-H amination of biaryl amines.

A palladium-catalyzed interannular C-H amination of biaryl amines with O-benzoylhydroxylamines is reported. This reaction undergoes smoothly with operational practicality and good tolerance of functional groups, thereby providing a concise synthesis of 2,2'-diaminobiaryls. Moreover, the readily accessible scale-up synthesis and the ability to transform the products into structurally diverse N-containing heterocycles demonstrate the synthetic potential of this catalytic protocol.

Effects of SOCS1-overexpressing dendritic cells on Th17- and Treg-related cytokines in COPD mice.

BACKGROUND: In this study, we established a chronic obstructive pulmonary disease (COPD) model by stimulating mice with cigarette smoke, and observed the effects of dendritic cells (DCs) overexpressing SOCS1 on Th17, Treg and other related cytokines in peripheral blood, bronchoalveolar lavage fluid and lung tissues of COPD mice. METHODS: After successfully transfecting DCs with overexpressing SOCS1 (DC-SOCS1), the mice were injected with DC-SOCS1 (1 × 106), DC-SOCS1 (2 × 106) and immature DCs (1 × 106) via tail vein on days 1 and 7 of COPD fumigation modeling. After day 28 of modeling, the peripheral blood, BALF and lung tissue samples were extracted from the mice, and the changes of DCs, Th17 and Treg cells and related cytokines were detected by immunohistochemistry, immunofluorescence, HE staining, flow cytometry and ELISA. RESULTS: The results showed that DC-SOCS1 was able to reduce the secretion of pro-inflammatory factors and increase the anti-inflammatory factors in the COPD mice, and the effect of high concentration (2 × 106 DC-SOCS1) was better than low concentration (1 × 106 DC-SOCS1). Moreover, the intervention effect was significant on day 1 compared with day 7. In the mice injected with DC-SOCS1, the expression of CD83, IL-4, Foxp3, and CCR6 was increased on day 1 than those on day 7, while IL-17 and IFN-γ was decreased. CONCLUSIONS: Intervention of COPD mice with high concentrations of DCs-SOCS1 reduced pro-inflammatory factor secretion and attenuated the inflammatory response in COPD. Trial registration Not applicable.

hAMSC Sheet Promotes Repair of Rabbit Osteochondral Defects.

Osteochondral lesion is clinically common disease, which has been recognized as one of the contributing factors of significant morbidity. Although current treatments have achieved good outcomes, some undesirable complications and failures are not uncommon. Cell sheet technology (CST), an innovative technology to harvest seed cells and preserve abundant ECM, has been widely used in various tissue regeneration. For osteochondral lesion, many studies focus on using CST to repair osteochondral lesion and have achieved good outcomes. In the previous study, we have demonstrated that hAMSC sheet had a positive effect on osteochondral lesion. Therefore, this study is aimed at comparing the effect of noninduced hAMSC sheet with chondrogenically induced hAMSC sheet on osteochondral lesion and cartilage regeneration.

Research Status and Prospect of Laser Scribing Process and Equipment for Chemical Milling Parts in Aviation and Aerospace.

Laser scribing in chemical milling is an important process which can effectively improve the precision and efficiency of chemical milling, and is of great significance to improve the thrust-weight ratio and manufacturing efficiency of aviation and aerospace parts. According to the scribing requirements in chemical milling for aviation and aerospace parts, the process and mechanism of laser scribing were studied and the influence of different process parameters for the quality of laser scribing was analyzed. Based on the review of related research literature, the laser scribing process, the ablation mechanism and technology of different materials and the selective laser removal process for "laser-coating-substrate" are summarized and discussed. Based on the requirements of high-precision laser scribing on complex surfaces, the current situation of laser scribing equipment is summarized. Finally, the practical challenges and key technical problems for the laser scribing process are summarized, and the application and development of laser scribing in aerospace manufacturing are prospected.

Clinicopathologic analysis of microscopic tumor extension in glioma for external beam radiotherapy planning.

BACKGROUND: There is no consensus regarding the clinical target volume (CTV) margins in radiotherapy for glioma. In this study, we aimed to perform a complete macropathologic analysis examining microscopic tumor extension (ME) to more accurately define the CTV in glioma. METHODS: Thirty-eight supra-total resection specimens of glioma patients were examined on histologic sections. The ME distance, defined as the maximum linear distance from the tumor border to the invasive tumor cells, was measured at each section. We defined the CTV based on the relationships between ME distance and clinicopathologic features. RESULTS: Between February 2016 and July 2020, a total of 814 slides were examined, corresponding to 162 slides for low-grade glioma (LGG) and 652 slides for high-grade glioma (HGG). The ME value was 0.69 ± 0.43 cm for LGG and 1.29 ± 0.54 cm for HGG (P < 0.001). After multivariate analysis, tumor grade, O6-methylguanine-DNA-methyltransferase promoter methylated status (MGMTm), isocitrate dehydrogenase wild-type status (IDHwt), and 1p/19q non-co-deleted status (non-codel) were positively correlated with ME distance (all P < 0.05). We defined the CTV of glioma based on tumor grade. To take into account approximately 95% of the ME, a margin of 1.00 cm, 1.50 cm, and 2.00 cm were chosen for grade II, grade III, and grade IV glioma, respectively. Paired analysis of molecularly defined patients confirmed that tumors that had all three molecular alterations (i.e., MGMTm/IDHwt/non-codel) were the most aggressive subgroups (all P < 0.05). For these patients, the margin could be up to 1.50 cm, 2.00 cm, and 2.50 cm for grade II, grade III, and grade IV glioma, respectively, to cover the subclinical lesions in 95% of cases. CONCLUSIONS: The ME was different between the grades of gliomas. It may be reasonable to recommend 1.00 cm, 1.50 cm, and 2.00 cm CTV margins for grade II, grade III, and grade IV glioma, respectively. Considering the highly aggressive nature of MGMTm/IDHwt/non-codel tumors, for these patients, the margin could be further expanded by 0.5 cm. These recommendations would encompass microscopic disease extension in 95% of cases. TRIAL REGISTRATION: The trial was registered with Chinese Clinical Trial Registry ( ChiCTR2100049376 ).

Quadriceps strength and knee joint function in patients with severe knee extension contracture following arthroscopic-assisted mini-incision quadricepsplasty.

PURPOSE: To evaluate reserve quadriceps function and improve knee activity in patients with severe knee extension contracture following arthroscopic-assisted mini-incision quadricepsplasty as well as post-operative complications. METHODS: From 2012 to 2019, 32 patients with severe knee extension contractures (less than 45° range of flexion) were treated with an all-arthroscopic release technique. The clinical results, including range of motion (ROM), quadriceps function (quadriceps index, QI), and knee function, were evaluated, and MRI of the healed tendon after partial quadricepsplasty was performed. The patellar track and length during knee flexion were measured on three normal knees under fluoroscopy. Three formalin-fixed lower limbs were used to mimic severely contracted quadriceps to evaluate the extension of the patellar track. RESULTS: The median follow-up time was 2.1 years (1-5 years). The average QI was 92.0 ± 6.2, and the quadriceps muscle strength was increased from 3.28 to 4.72. At the final follow-up, 90% of the patients had no difficulty going upstairs, going downstairs, or rising from a chair. The ROM improved by 25.69 ± 3.6 preoperatively to 105.88 ± 6.6 at the final follow-up (P < 0.001). The open surgery showed that a 2-cm extension could be achieved by partly cutting the quadriceps tendon, and two cuts achieved a total extension of 5.2 ± 0.52 cm. The patellar tracking distance was 7.7 ± 0.43 cm, and the gap between the patella and femur was also reduced. CONCLUSION: Partial quadricepsplasty of the rectus femoris extended the contracted quadriceps and maintained quadriceps strength, allowing for full knee flexion and satisfactory clinical outcomes of knee function with few complications.

Multi-Frequency Ultrasonic Extraction of Anthocyanins from Blueberry Pomace and Evaluation of Its Antioxidant Activity.

BACKGROUND: A large amount of blueberry pomace is discarded and wasted. OBJECTIVE: To make full use of blueberry pomace and extract anthocyanins. METHOD: Multi-frequency ultrasound was used to extract anthocyanins from blueberry pomace. The effects of different extraction conditions on the anthocyanin yields were studied. The antioxidant activity of anthocyanins was evaluated, and the main anthocyanin components were identified by HPLC-electrospray ionization (ESI)-MS/MS. RESULTS: The optimal anthocyanin extraction conditions were as follows: dual-frequency ultrasound of 40 + 80 kHz, ultrasonic power of 350 W, extraction temperature of 50°C, and extraction time of 40 min. Compared with single frequency (25 kHz) and tri-frequency ultrasound (25 + 40 + 80 kHz), the anthocyanin yield with dual-frequency ultrasound increased by 15.26% and 5.45% respectively. Furthermore, the antioxidant activities (DPPH, hydroxyl radical scavenging ability, and reducing power) of anthocyanins extracted with dual-frequency ultrasound were all higher than those without ultrasound. Seven kinds of anthocyanins were identified by HPLC-ESI-MS/MS. CONCLUSIONS: Dual-frequency ultrasound had a higher extraction yield than single frequency ultrasound, tri-frequency ultrasound, and no ultrasound. HIGHLIGHTS: Dual-frequency ultrasonic technology provides an effective approach for improving the extraction yield of anthocyanins from blueberry pomace.