Search

For the arbitrary-order systems with disturbances and uncertainties, this article proposes a novel adaptive second-order fixed-time nonsingular terminal sliding mode control based on barrier function (BF). First, a second-order integral terminal sliding surface is designed to avoid singular problems, achieve fixed time stability, and reduce steady-state errors. Second, a high-order controller based on BF is constructed to further compensate for unknown uncertainties and disturbances, which ensures the adaptive adjustment of the controller gain with the change of disturbances. Then, by the Lyapunov stability theorem, it proves the fixed-time convergence of the system, which is only dependent on the controller parameters, and eliminates the slow-varying assumptions commonly present in the traditional adaptive control law. Finally, the proposed method is simulated and compared with some typical methods to prove the advantages of the proposed method. And it is further extended to a multicylinder hydraulic press model to verify its applicability in engineering practice.

Periodontitisis an inflammatory disease that is characterized by progressive destruction of the periodontium and causes tooth loss in adults. Periodontitis is known to be associated with dysbiosis of the oral microflora, which is often linked to various diseases. However, the complexity of plaque microbial communities of periodontitis, antibiotic resistance, and enhanced virulence make this disease difficult to treat. In this study, using metagenomic shotgun sequencing, we investigated the etiology, antibiotic resistance genes(ARGs), and virulence genes(VirGs) of periodontitis. We revealed a significant shift in the composition of oral microbiota as well as several functional pathways that were represented significantly more abundantly in periodontitis patients than in controls. In addition, we observed several positively selected ARGs and VirGs with the Ka/Ks ratio > 1 by analyzing our data and a previous periodontitis dataset, indicating that ARGs and VirGs in oral microbiota may be subjected to positive selection. Moreover, 5 of 12 positively selected ARGs and VirGs in periodontitis patients were found in the genomes of respiratory tract pathogens. Of note, 91.8% of the background VirGs with at least one non-synonymous single-nucleotide polymorphism for natural selection were also from respiratory tract pathogens. These observations suggest a potential association between periodontitis and respiratory infectionat the gene level. Our study enriches the knowledge of pathogens and functional pathways as well as the positive selection of antibiotic resistance and pathogen virulence in periodontitis patients, and provides evidence at the gene level for an association between periodontitis and respiratory infection.

Neurodevelopmental disorders, including autism spectrum disorder (ASD), intellectual disability (ID), developmental disorders (DD) and epileptic encephalopathy (EE), have a strong clinical comorbidity, which indicates a common genetic etiology across various disorders. However, the underlying genetic mechanisms of comorbidity and specificity remain unknown across neurodevelopmental disorders. Based on de novo mutations, we compared systematically the functional characteristics between shared and unique genes under these disorders, as well as the spatiotemporal trajectory of development in brain and common molecular pathways of all shared genes. We observed that shared genes present more constrained against functional rare genetic variation, and harbor more pathogenic rare variants than do unique genes in each disorder. Furthermore, 71 shared genes formed two clusters related to synaptic transmission, transcription regulation and chromatin regulator. Particularly, we also found that two core genes STXBP1and SCN2A, that were shared by the four neurodevelopmental disorders showed prominent pleiotropy. Our findings shed light on the shared and specific patterns across neurodevelopmental disorders and will enable us to further comprehend the etiology and provide valuable information for the diagnosis of neurodevelopmental disorders.

Periodontitis is an inflammatory disease which is characterized by progressive destruction of the periodontium and causes tooth loss in adults. Periodontitis is known to be associated with dysbiosis of the oral microflora which is often linked to various diseases. However, the complexity of plaque microbial communities of periodontitis, antibiotic resistance, and enhanced virulence make this disease difficult to treat. Therefore, we used metagenomic shotgun sequencing in this study to investigate the etiology, antibiotic-resistant genes (ARGs), and virulence genes (VirGs) of periodontitis. We revealed a significant shift in the composition of oral microbiota as well as several functional pathways that were represented significantly more abundant in periodontitis patients than in controls. In addition, we observed several positively selected ARGs and VirGs with the Ka/Ks ratio > 1 by analyzing our data and a previous periodontitis dataset, indicating that ARGs and VirGs in oral microbiota may suffer from positive selection. Moreover, 5 of 12 positively selected ARGs and VirGs in periodontitis patients were found in the genomes of respiratory tract pathogens. Of note, 91.8% of the background VirGs with at least one non-synonymous single-nucleotide polymorphism for natural selection were also from respiratory tract pathogens. These observations suggest a potential association between periodontitis and respiratory infection at the gene level. Our study enriches the knowledge of pathogens and functional pathways as well as the positive selection of antibiotic resistance and pathogen virulence in periodontitis patients, and provides evidence from the gene level for an association between periodontitis and respiratory infection.