45 research outputs found

    Investigation on gait by means of factorial moments

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    By means of Factorial Moments(FM), the long-range correlations embedded in gait time series are investigated. It is found that FM is an effective tool to deal with this kind of time series. Keywords: Factorial Moments,Time series, Long-range correlationsComment: 10pages, 3figures. submitte

    A Novel Digital Twin Framework for Aeroengine Performance Diagnosis

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    Aeroengine performance diagnosis technology is essential for ensuring flight safety and reliability. The complexity of engine performance and the strong coupling of fault characteristics make it challenging to develop accurate and efficient gas path diagnosis methods. To address these issues, this study proposes a novel digital twin framework for aeroengines that achieves the digitalization of physical systems. The mechanism model is constructed at the component level. The data-driven model is built using a particle swarm optimization–extreme gradient boosting algorithm (PSO-XGBoost). These two models are fused using the low-rank multimodal fusion method (LWF) and combined with the sparse stacked autoencoder (SSAE) to form a digital twin framework of the engine for performance diagnosis. Compared to methods that are solely based on mechanism or data, the proposed digital twin framework can effectively use mechanism and data information to improve the accuracy and reliability. The research results show that the proposed digital twin framework has an error rate of 0.125% in predicting gas path parameters and has a gas path fault diagnosis accuracy of 98.6%. Considering that the degradation cost of a typical flight mission for only one aircraft engine after 3000 flight cycles is approximately USD 209.5, the proposed method has good economic efficiency. This framework can be used to improve engine reliability, availability, and efficiency, and has significant value in engineering applications

    Saprophytic <i>Bacillus</i> Accelerates the Release of Effective Components in Agarwood by Degrading Cellulose

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    The value of Agarwood increases with time due to the gradual release of its major components, but the mechanism behind this remains unclear. Herein we reveal that the potential driving force of this process is the degradation of cellulose in Agarwood by its saprophytic Bacillus subtilis. We selected 10-year-old Agarwood from different places and then isolated the saprophytic bacteria. We confirmed these bacteria from different sources are all Bacillus and confirmed they can degrade cellulose, and the highest cellulase activity reached 0.22 U/mL. By co-cultivation of the bacterium and Agarwood powder, we found that three of the strains could release the effective components of Agarwood, while they had little effect in increasing the same components in living Aquilaria sinensis. Finally, we demonstrated that these saprophytic Bacillus subtilis have similar effects on Zanthoxylum bungeanum Maxim and Dalbergiaod orifera T. Chen, but not on Illicium verum Hook. f, Cinnamomum cassia Presl and Phellodendron chinense Schneid. In conclusion, our experiment revealed that the saprophytic Bacillus release the effective components of Agarwood by degrading cellulose, and we provide a promising way to accelerate this process by using this bacterial agent

    Molecular dynamics investigation of the interaction between Colletotrichum capsici cutinase and berberine suggested a mechanism for reduced enzyme activity.

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    Berberine is a promising botanical pesticide against fungal plant pathogens. However, whether berberine inhibits the invasion of fungal pathogen across plant surface remains unclear. Here we demonstrated that the enzyme activities of purified cutinase from fungal pathogen Colletotrichum capsici were partially inhibited in presence of berberine toward different substrates. Molecular dynamics simulation results suggested the rigidity of cutinase was decreased with berberine added into the system. Interestingly, aggregations of berberine to the catalytic center of cutinase were observed, and stronger hydrophobic interactions were detected between key residue His 208 and berberine with concentrations of berberine increased. More importantly, this hydrophobic interaction conferred conformational change of the imidazole ring of His 208, which swung out of the catalytic center to an inactive mode. In summary, we provided the molecular mechanism of the effect of berberine on cutinase from C. capsici

    Downregulation of lncRNA NEAT1 interacts with miR-374b-5p/PGAP1 axis to aggravate the development of osteoarthritis

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    Abstract Background Osteoarthritis (OA), characterized by inflammation and articular cartilage degradation, is a prevalent arthritis among geriatric population. This paper was to scrutinize the novel mechanism of long noncoding RNA (lncRNA) NEAT1 in OA etiology. Methods A total of 10 OA patients and 10 normal individuals was included in this study. Cell model of OA was built in human normal chondrocytes induced by lipopolysaccharide (LPS). An OA Wistar rat model was established through intra-articular injection of L-cysteine and papain mixtures (proportion at 1:2) into the right knee. Quantitative reverse transcription-polymerase chain reaction was employed to ascertain the expression levels of NEAT1, microRNA (miR)-374b-5p and post-GPI attachment to protein 1 (PGAP1), while dual-luciferase reporter experiments were used for the validation of target relationship among them. Cell cycle and apoptosis were calculated by flow cytometry analysis. CCK-8 assay was done to evaluate the proliferative potentials of chondrocytes. The levels of cell cycle-related proteins (Cyclin A1, Cyclin B1 and Cyclin D2) and pro-apoptotic proteins (Caspase3 and Caspase9) were measured by western blotting. Tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-6 levels were determined via ELISA. Hematoxylin & eosin (HE) Staining was used for pathological examination in OA rats. Results Pronounced downregulation of NEAT1 and PGAP1 and high amounts of miR-374b-5p were identified in OA patients, LPS-induced chondrocytes and OA rats. NEAT1 targeted miR-374b-5p to control PGAP1 expression. Loss of NEAT1 or upregulation of miR-374b-5p dramatically accelerated apoptosis, led to the G1/S arrest and promoted the secretion of inflammatory cytokines in LPS-induced chondrocytes, while ectopic expression of PGAP1 exhibited the opposite influences on chondrocytes. Additionally, we further indicated that upregulation of miR-374b-5p attenuated the effects of PGAP1 overexpression on LPS-induced chondrocytes. Conclusions Reduced NEAT1 induces the development of OA via miR-374b-5p/PGAP1 pathway. This suggests that the regulatory axis NEAT1/miR-374b-5p/PGAP1 is a novel and prospective target for OA treatment
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