Rapid in situ identification of honey authenticity based on RP-Nano-ESI-MS using online desalting.

High-content sugar in honey frequently results in severe matrix effects and requires complex pretreatment prior to analysis, posing significant challenges for the rapid analysis of honey. In this study, the reversal polarity nano-electrospray ionization mass spectrometry (RP-Nano-ESI-MS) analysis was developed for the direct evaluation of honey samples. The results indicated that RP-Nano-ESI-MS significantly mitigated the matrix effects induced by high-content sugar through the implementation of online desalting. Furthermore, RP-Nano-ESI-MS has been proven capable of not only differentiating acacia honey adulterated with 10% rape honey, but also effectively distinguishing six types of honey and exhibiting remarkable proficiency in detecting honey adulteration and botanical traceability. Additionally, RP-Nano-ESI-MS exhibited strong quantitative abilities, effectively characterizing variations in amino acid composition among six types of honey with high stability and reproducibility. Our studies underscore the significant potential of RP-Nano-ESI-MS for its rapid in situ analysis of sugar-rich foods like honey, especially in their authenticity verification.

Identification and quality evaluation of Lushan Yunwu tea from different geographical origins based on metabolomics.

The relationship between the chemical composition and quality of Lushan Yunwu tea (LYT) from different geographical origins is not clear. Sensory evaluation, metabolomics analyses combined with chemometrics were conducted on LYT from 8 different geographical origins, and altitude was identified as the main factor responsible for the differences among LYT. A total of 32 non-volatile and 27 volatile compounds were identified as marker metabolites to distinguish the origins of high altitudes from those of low altitudes. LYT samples from higher altitude areas contained more free amino acids, sugars, and organic acids, and less catechins, which may contribute to the reduction of bitterness and astringency and the enhancement of umami. The contents of geranylacetone, ethyl hexanoate, ethyl caprylate, 3-carene, d-cadinene, linalool, nerol, and nerolidol in high altitude areas were higher than those in low altitude areas, indicating that LYT from high altitude had strong floral and fruity aroma. The altitudes were positively correlated with pH value, total flavonoids, soluble protein, total free amino acids, and the antioxidant capacities of the LYT. This study provided a theoretical basis for the study of the effect of altitude on tea quality.

Long-term administration of royal jelly regulates age-related disorders and improves gut function in naturally aging mice.

A natural aging mouse model can exhibit physiological characteristics that closely resemble those of human aging. Through long-term observation, it reflects the occurrence and development of the aging process more accurately. Although numerous beneficial effects of royal jelly (RJ) have been extensively demonstrated in multiple experimental models, the effects of RJ on naturally aging mice have not yet been investigated. In this study, middle-aged male C57BL/6J mice were given RJ for 9 consecutive months to investigate its impact on the intestinal barrier function, gut microbiota, short-chain fatty acids (SCFAs) content and possible mechanisms. The results confirmed that RJ modulated serum lipids by reducing the levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C). Additionally, it protected the liver by increasing antioxidant enzyme levels while decreasing inflammatory cytokines TNF-α (by 51.97%), IL-6 (by 29.73%), and IL-1ß (by 43.89%). Furthermore, RJ inhibited the expression of cell cycle-dependent kinase inhibitors including p16, p21, and p53. Importantly, RJ ameliorated gut dysfunctions by inhibiting reduction of tight junction proteins and reducing inflammatory cytokines content in the colon. We also observed an alteration in gut microbiota characterized by an elevated ratio of Firmicutes to Bacteroides (F/B) along with increased abundance of beneficial bacteria, i.e., Lachnospiraceae NK4A136 and Akkermansia. Correlation analysis revealed positive associations between most bacterial genera and SCFAs production. Functional profiling of gut microbiota composition indicated that RJ intervention regulated amino acid metabolism, glycan biosynthesis, and cofactor/vitamin metabolism. Overall, our findings provide an effective dietary intervention strategy for modulating age-associated frailty through the modulation of the gut microbiota.

Co-doped NiFe carbonate hydroxide hydrate nanosheets with edge effect constructed from spent lithium-ion battery ternary cathodes for oxygen evolution reaction.

The recycling of spent lithium-ion batteries (LIBs) has received increasing attention for environment and resource reclamation. Converting LIBs wastes into high-efficiency catalysts is a win-win strategy for realizing resource reclamation and addressing sustainable energy challenges. Herein, we developed a simple method to upcycle spent-LIBs cathode powder into Co-doped NiFe carbonate hydroxide hydrate (Co/NFCH-FF) as a low-cost and efficient oxygen evolution reaction (OER) electrocatalyst. The optimized Co/NFCH-FF electrode appears very competitive OER performances with low overpotentials of 201 and 249 mV at 10 and 100 mA cm-2, respectively, a small Tafel slope of 48.4 mV dec-1, and a high long-term stability. Moreover, we reveal that the existence of Co atoms leads to the formation of a crystalline/amorphous (c/a) interface at the Co/NFCH nanosheet edge, inducing the nanosheets possess a unique edge effect to enhance electric fields and accumulate hydroxide ions (OH-) at the edge during the OER process. Benefiting from edge effect, Co/NFCH-FF shows outstanding intrinsic activity. Furthermore, Co atoms as dopants stabilize the electronic structure of Co/NFCH-FF, enabling Co/NFCH-FF to exhibit excellent catalytic stability. This work provides an effective strategy for converting the end-life LIBs to high-performance multicomponent OER electrocatalysts and proposes new insights into the mechanism of enhanced catalytic activity of Co/NFCH.

Vascularized fascial flap for reconstruction of combined oral mucosa-mandibular defects: The multi-modal biological assessment.

OBJECTIVE: The reconstruction of composite defects in the oral and maxillofacial region using vascularized fascial flaps, such as the fibular, iliac, and temporal fascial flaps, has gained increasing attention among surgeons. However, there remains uncertainty regarding the suitability of fascial flaps as transplants, as well as their healing processes and outcomes, due to their non-mucosal nature. This study aims to comprehensively assess the biological aspects of vascularized fascial flaps at clinical, histological, and genetic levels, with the goal of providing essential biological references for their clinical application. STUDY DESIGN: This study enrolled three patients who underwent reconstruction of combined oral mucosa-mandibular defects using fibular vascularized fascial flaps between 2020 and 2023. Data regarding changes in the appearance of the fascial flaps, bulk-RNA sequencing, and histological slices of initial fascia, initial gingiva, and transformed fascia were collected and analyzed. RESULTS: Within three months, the fascial flaps exhibited rapid epithelial coverage and displayed distinct characteristics resembling mucosa. High-throughput RNA sequencing analyses and histological slices revealed that the transformed fascia exhibited tissue structures similar to mucosa and demonstrated unique advantages in promoting blood vessel formation and reducing scarring through the high-level expression of relevant genes. CONCLUSION: These findings emphasize the potential and feasibility of utilizing vascularized fascial flaps for oral mucosa reconstruction, establishing their unique advantage as transplant materials, and providing significant biological information and references for their selection and clinical application.

Application of Oral Retractor for Lip Injury Protection in Oral and Maxillofacial Surgeries: A Randomized Controlled Trial.

PURPOSE: Iatrogenic lip injury may occur during oral and maxillofacial surgical procedures. This study aimed to evaluate the effect of oral retractors on iatrogenic lip injury prevention during intraoral procedures of oral and maxillofacial surgery. METHODS: We conducted a randomized controlled trial and included patients who underwent intraoral procedures of oral and maxillofacial surgery. Patients were randomly allocated to receive oral retractor (intervention group) or traditional procedure without lip protection (control group). The incidence of lip injury was the outcome variable. Other study variables included surgical time and satisfaction of patients and surgeons with treatment experience evaluated by visual analog scale (VAS). Student t test and χ 2 test were used to compare both groups' variables and measure the relationship between the predictor variable and the outcome variable. P <0.05 was considered significant for all analyses. RESULTS: A total of 114 patients were included, with 56 allocated to intervention group and 58 to control group. The results showed that the application of an oral retractor did not significantly increase surgical time ( P =0.318). A total of 12 patients had lip injury, with 1 in the intervention group and 11 in the control group ( P =0.003). For the assessment of satisfaction with treatment experience, the intervention group had significantly higher VAS scores for doctors and patients ( P <0.05). CONCLUSIONS: We found that the oral retractor was a good tool for iatrogenic lip injury prevention in oral and maxillofacial surgical procedures and could be considered in clinical treatment.

Reconstruction of Extensive Maxillary Defects Using Flow-Through Fibula Free Flap With Anterolateral Thigh Free Flap.

BACKGROUND: The maxillary defects left unreconstructed or inadequately reconstructed often result in significant functional and esthetic impairments. Adequate reconstruction of extensive maxillary defects requires a sufficient volume of hard and soft tissues. METHODS: A 48-year-old male presenting bilateral extensive maxillary defects underwent secondary reconstruction with a flow-through fibula free flap in combination with an anterolateral thigh free flap. RESULTS: The use of flow-through technique allowed minimizing the problem of limited recipient vessels and the length of free flap vascular pedicle usually encountered in secondary reconstruction. The bilateral maxillary defects were successfully reconstructed, and the postoperative outcomes were uneventful. The patient was satisfied with the treatment outcomes. He is being followed up and was referred to the implantology department for the placement of osseointegrated dental implants. CONCLUSIONS: The flow-through fibula free flap, in combination with the anterolateral thigh free flap, was found reliable and feasible for this case of secondary reconstruction of bilateral maxillary defects. This technique has provided satisfactory functional and esthetic outcomes and effectively improved the patient's self-esteem.

Evidence linking COVID-19 and the health/well-being of children and adolescents: an umbrella review.

BACKGROUND: Experiences during childhood and adolescence have enduring impacts on physical and mental well-being, overall quality of life, and socioeconomic status throughout one's lifetime. This underscores the importance of prioritizing the health of children and adolescents to establish an impactful healthcare system that benefits both individuals and society. It is crucial for healthcare providers and policymakers to examine the relationship between COVID-19 and the health of children and adolescents, as this understanding will guide the creation of interventions and policies for the long-term management of the virus. METHODS: In this umbrella review (PROSPERO ID: CRD42023401106), systematic reviews were identified from the Cochrane Database of Systematic Reviews; EMBASE (OvidSP); and MEDLINE (OvidSP) from December 2019 to February 2023. Pairwise and single-arm meta-analyses were extracted from the included systematic reviews. The methodological quality appraisal was completed using the AMSTAR-2 tool. Single-arm meta-analyses were re-presented under six domains associated with COVID-19 condition. Pairwise meta-analyses were classified into five domains according to the evidence classification criteria. Rosenberg's FSN was calculated for both binary and continuous measures. RESULTS: We identified 1551 single-arm and 301 pairwise meta-analyses from 124 systematic reviews that met our predefined criteria for inclusion. The focus of the meta-analytical evidence was predominantly on the physical outcomes of COVID-19, encompassing both single-arm and pairwise study designs. However, the quality of evidence and methodological rigor were suboptimal. Based on the evidence gathered from single-arm meta-analyses, we constructed an illustrative representation of the disease severity, clinical manifestations, laboratory and radiological findings, treatments, and outcomes from 2020 to 2022. Additionally, we discovered 17 instances of strong or highly suggestive pairwise meta-analytical evidence concerning long-COVID, pediatric comorbidity, COVID-19 vaccines, mental health, and depression. CONCLUSIONS: The findings of our study advocate for the implementation of surveillance systems to track health consequences associated with COVID-19 and the establishment of multidisciplinary collaborative rehabilitation programs for affected younger populations. In future research endeavors, it is important to prioritize the investigation of non-physical outcomes to bridge the gap between research findings and clinical application in this field.

A Contraband Detection Scheme in X-ray Security Images Based on Improved YOLOv8s Network Model.

X-ray inspections of contraband are widely used to maintain public transportation safety and protect life and property when people travel. To improve detection accuracy and reduce the probability of missed and false detection, a contraband detection algorithm YOLOv8s-DCN-EMA-IPIO* based on YOLOv8s is proposed. Firstly, the super-resolution reconstruction method based on the SRGAN network enhances the original data set, which is more conducive to model training. Secondly, DCNv2 (deformable convolution net v2) is introduced in the backbone network and merged with the C2f layer to improve the ability of the feature extraction and robustness of the model. Then, an EMA (efficient multi-scale attention) mechanism is proposed to suppress the interference of complex background noise and occlusion overlap in the detection process. Finally, the IPIO (improved pigeon-inspired optimization), which is based on the cross-mutation strategy, is employed to maximize the convolutional neural network's learning rate to derive the optimal group's weight information and ultimately improve the model's detection and recognition accuracy. The experimental results show that on the self-built data set, the mAP (mean average precision) of the improved model YOLOv8s-DCN-EMA-IPIO* is 73.43%, 3.98% higher than that of the original model YOLOv8s, and the FPS is 95, meeting the deployment requirements of both high precision and real-time.

Identification and Characterization of Polyamine Metabolism in Citrus in Response to 'Candidatus Liberibacter asiaticus' Infection.

Citrus Huanglongbing, one of the most devastating citrus diseases, is caused by 'Candidatus Liberibacter asiaticus' (CLas). Polyamines are aliphatic nitrogen-containing compounds that play important roles in disease resistance and are synthesized primarily by two pathways: an arginine decarboxylation pathway and an ornithine decarboxylation pathway. However, it is unclear whether polyamines play a role in the tolerance of citrus to infection by CLas and, if so, whether one or both of the core polyamine metabolic pathways are important. We used high-performance liquid chromatography and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry to detect the contents of nine polyamine metabolism-related compounds in six citrus cultivars with varying levels of tolerance to CLas. We also systematically detected the changes in polyamine metabolism-related compounds and H2O2 contents and compared the gene expression levels and the activities of enzymes involved in the polyamine metabolic pathway among healthy, asymptomatic, and symptomatic leaves of Newhall navel oranges infected with CLas. The tolerant and moderately tolerant varieties showed higher polyamine metabolism-related compound levels than those of susceptible varieties. Compared with the healthy group, the symptomatic group showed significantly increased contents of arginine, ornithine, γ-aminobutyric acid, and putrescine by approximately 180, 19, 1.5, and 0.2 times, respectively, and upregulated expression of biosynthetic genes. Arginase and ornithine decarboxylase enzyme activities were the highest in the symptomatic group, whereas arginine decarboxylase and agmatine deiminase enzyme activities were the highest in the asymptomatic group. The two polyamine biosynthetic pathways showed different trends with the increase of the CLas titer, indicating that polyamines were mainly synthesized through the arginine decarboxylase pathway in the asymptomatic leaves and were synthesized via the ornithine decarboxylase pathway in symptomatic leaves. These findings provide new insight into the changes in polyamine metabolism in citrus infected with CLas.

Metabolomics and network pharmacology reveal the mechanism of Castanopsis honey against Streptococcus pyogenes.

Streptococcus pyogenes (GAS) is one of the most virulent and infectious bacteria, severely threatening health and lives of people worldwide. Honey has been proven to have effective capability against GAS, but the underlying metabolites and mechanisms are still unclear. In this study, the Castanopsis honey (CH) showed significant antibacterial ability compared to other seven kinds of honey and artificial honey. Furthermore, the antibacterial metabolites and their targets in CH were screened by combined method of metabolomics, network pharmacology, and molecular docking. The results suggested that the activities of two antioxidant enzymes, glutathione peroxidase and tyrosyl tRNA synthetase identified as the primary targets, were significantly inhibited by CH, which significantly increased the level of oxidative stress in GAS. The results revealed a possibly novel mechanism regulating the oxidative stress and inhibits the growth in bacteria, providing strong experimental evidence to support the further development of CH as a novel antibacterial agent.

Innovative principle of implant-oriented fibula placement in mandibular reconstruction using double-barrel fibula and simultaneous implants: A technical note.

Simultaneous or secondary inserted implants with double-barrel fibula to reconstruct the mandible have become a common method. However, difficulties in later restoration caused by placement errors of fibula or incipiently placed implants have also been reported in some studies. This note describes a novel technique of implant-oriented guide plates helpful for mandible ablation, fibula segmentation and positioning, and implant placement. We design a series of guide plates especially an implant-fibula placing guide plate, and record and fix the relative spatial positions of the remaining teeth, the simultaneous implants and upper fibula. During surgery, the placement of upper fibula is oriented towards appropriate placement of implants. Therefore, the position of upper fibula can meet the requirements of simultaneous implant as much as possible. Within the limits of present observation, we believe that this technique may increase the manipuility while reducing the errors and the risk of complications.

Reconstruction of Total Maxillectomy Defects Using Coronoid-Temporalis Pedicled Flap, Titanium Mesh, and Free Flap.

The maxilla plays a crucial role in maintaining midfacial contour, supporting the globe and dentition and separating the oral and nasal cavity. Reconstruction of total maxillectomy defects has always been a challenge in head and neck surgery. In recent years, on the basis of existing methods, we have used the coronoid-temporalis pedicled flap combined with personalized titanium mesh and free flap to reconstruct total maxillectomy defects. This combination of multiple methods can restore the functional subunits of the maxilla. In this report, we introduce our surgical procedures in detail and assess the postoperative effects. Postoperative facial aesthetic outcomes were satisfactory in all 8 patients. None of the patients showed diplopia, oral-nasal reflux, hypernasality, titanium mesh exposure, or trismus. This new surgical procedure may be a simple and feasible option for the reconstruction of total maxillectomy defects.

Correntropy-Induced Wasserstein GCN: Learning Graph Embedding via Domain Adaptation.

Graph embedding aims at learning vertex representations in a low-dimensional space by distilling information from a complex-structured graph. Recent efforts in graph embedding have been devoted to generalizing the representations from the trained graph in a source domain to the new graph in a different target domain based on information transfer. However, when the graphs are contaminated by unpredictable and complex noise in practice, this transfer problem is quite challenging because of the need to extract helpful knowledge from the source graph and to reliably transfer knowledge to the target graph. This paper puts forward a two-step correntropy-induced Wasserstein GCN (graph convolutional network, or CW-GCN for short) architecture to facilitate the robustness in cross-graph embedding. In the first step, CW-GCN originally investigates correntropy-induced loss in GCN, which places bounded and smooth losses on the noisy nodes with incorrect edges or attributes. Consequently, helpful information are extracted only from clean nodes in the source graph. In the second step, a novel Wasserstein distance is introduced to measure the difference in marginal distributions between graphs, avoiding the negative influence of noise. Afterwards, CW-GCN maps the target graph to the same embedding space as the source graph by minimizing the Wasserstein distance, and thus the knowledge preserved in the first step is expected to be reliably transferred to assist the target graph analysis tasks. Extensive experiments demonstrate the significant superiority of CW-GCN over state-of-the-art methods in different noisy environments.

Promotion effect of TGF-ß-Zfp423-ApoD pathway on lip sensory recovery after nerve sacrifice caused by nerve collateral compensation.

Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-ß inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-ß-Zfp423-ApoD pathway.

Citrus Honey Ameliorates Liver Disease and Restores Gut Microbiota in Alcohol-Feeding Mice.

Citrus honey (CH) is rich in nutrients that have a wide variety of biological functions, such as antibacterial, anti-inflammatory, and antioxidant activities, and which demonstrate therapeutic properties, such as anti-cancer and wound-healing abilities. However, the effects of CH on alcohol-related liver disease (ALD) and the intestinal microbiota remain unknown. This study aimed to determine the alleviating effects of CH on ALD and its regulatory effects on the gut microbiota in mice. In total, 26 metabolites were identified and quantified in CH, and the results suggested that the primary metabolites were abscisic acid, 3,4-dimethoxycinnamic acid, rutin, and two markers of CH, hesperetin and hesperidin. CH lowered the levels of aspartate aminotransferase, glutamate aminotransferase, and alcohol-induced hepatic edema. CH could promote the proliferation of Bacteroidetes while reducing the abundance of Firmicutes. Additionally, CH also showed some inhibitory effects on the growth of Campylobacterota and Turicibacter. CH enhanced the secretion of short-chain fatty acids (SCFAs), such as acetic acid, propionic acid, butyric acid, and valeric acid. Given its alleviating functions in liver tissue damage and its regulatory effects on the gut microbiota and SCFAs, CH could be a promising candidate for the therapeutic treatment of ALD.

Identification of the botanical origins of honey based on nanoliter electrospray ionization mass spectrometry.

The botanical origins of honey are important for the quality control and commercialization of honey. In this research, we established a nanoliter electrospray ionization mass spectrometry (Nano-ESI-MS) method to identify Castanopsis honey (CH), Eurya honey (EH), Dendropanax dentiger honey (DH), and Triadica cochinchinensis honey (TH). In total, 38 compounds were identified based on the collision-induced dissociation experiments by Nano-ESI-MS with 16 differential compounds and 7 quantified as potential differential markers. These four types of honey were distinguished from each other by their mass spectrometry data combined with multivariate analysis with three out of the 7 differential markers, i.e., phenethylamine, tricoumaroyl spermidine, and (+/-)-abscisic acid, identified as potential markers for CH, EH, and DH, respectively. Both the qualitative and quantitative results derived from Nano-ESI-MS were further verified by UPLC-Q/TOF-MS. Our studies provided the significant potential of the Nano-ESI-MS method in the identification of the botanical origins of different kinds of honey.

A tooth-supported titanium mesh bending and positioning module for alveolar bone augmentation and improving accuracy.

OBJECTIVE: Guided bone regeneration with titanium mesh is a commonly used bone augmentation technique. However, deformation and sliding may occur during the installation of titanium mesh, which may lead to poor accuracy of bone augmentation. This article presented three cases, which describe a tooth-supported titanium mesh bending and positioning module aiming to improve the precision of bone augmentation. CLINICAL CONSIDERATIONS: After designing the ideal bone increment volume digitally, print out the difference bone module between the ideal and existing bone mass and one or two wings. The wings are supported by the adjacent teeth to show the ideal bone mass in the patients' mouth. Finally, the titanium mesh is bent and installed in the ideal position by the module. CONCLUSIONS: A favorable outcome has been preliminarily confirmed in these cases, the average vertical bone gain was 4.16 mm and the average horizontal gain was 7.48 mm after 6 months. Using the module in the treatment of patients with bone augmentation can effectively improve the accuracy, the maximum deviation was 1.5 mm and the mean was 0.6 mm. CLINICAL SIGNIFICANCE: This study improves the bone augmentation technology with titanium mesh. The titanium mesh is fixed in the ideal position, which facilitates subsequent implantation and denture repair.

Impedance Iterative Learning Backstepping Control for Output-Constrained Multisection Continuum Arms Based on PMA.

BACKGROUND: Pneumatic muscle actuator (PMA) actuated multisection continuum arms are widely applied in various fields with high flexibility and bionic properties. Nonetheless, their kinematic modeling and control strategy proves to be extremely challenging tasks. METHODS: The relationship expression between the deformation parameters and the length of PMA with the geometric method is obtained under the assumption of piecewise constant curvature. Then, the kinematic model is established based on the improved D-H method. Considering the limitation of PMA telescopic length, an impedance iterative learning backstepping control strategy is investigated. For one thing, the impedance control is utilized to ensure that the ideal static balance force is maintained constant in the Cartesian space. For another, the iterative learning backstepping control is applied to guarantee that the desired trajectory of each PMA can be accurately tracked with the output-constrained requirement. Moreover, iterative learning control (ILC) is implemented to dynamically estimate the unknown model parameters and the precondition of zero initial error in ILC is released by the trajectory reconstruction. To further ensure the constraint requirement of the PMA tracking error, a log-type barrier Lyapunov function is employed in the backstepping control, whose convergence is demonstrated by the composite energy function. RESULTS: The tracking error of PMA converges to 0.004 m and does not exceed the time-varying constraint function through cosimulation. CONCLUSION: From the cosimulation results, the superiority and validity of the proposed theory are verified.

Periodic event-triggered sliding mode control for lower limb exoskeleton based on human-robot cooperation.

This paper presents a periodic event-triggered sliding mode control (SMC) scheme based on human-robot cooperation for lower limb exoskeletons. Firstly, a Genetic Algorithm-Back propagation (GA-BP) neural network is proposed to estimate the motion intention of the wearer through electromyography (EMG) signals. Secondly, the periodic event-triggered SMC strategy based on tanh function is designed to ensure the asymptotic convergence of the exoskeleton system and save communication resources, where the detailed expressions of sampling period and control gain are designed. Finally, comparative simulation and experimental analysis is presented to verify the effectiveness of the proposed control method.