Fault diagnosis of electro-mechanical actuator based on WPD-STFT time-frequency entropy and PNN

Electro-mechanical actuators (EMAs) are increasingly being used as critical actuation devices of the aircraft. It will cause serious accidents once the fault of EMAs occurs, thus the fault diagnosis of EMAs is essential to maintain the normal operation of aircraft. In this paper, a method based on WPD-STFT time-frequency entropy and PNN is proposed to achieve fault diagnosis of EMAs by processing the vibration signals collected by the accelerometer installed in the EMAs. Firstly, the vibration signals are decomposed by wavelet packet to obtain the signal components of different frequency bands, the signal components are subjected to STFT and spectrograms are obtained. Then, time-frequency entropy is calculated and combined with principal component analysis (PCA) for dimension reduction as the feature vector. Finally, the probabilistic neural network (PNN) classifier is introduced to classify the fault modes. The experimental result shows that this method can accomplish the accurate fault diagnosis of EMAs. Moreover, the performance of the proposed WPD-STFT time-frequency entropy method has an advantage over that of WPD-PCA method or STFT combined with mass-moment entropy method for feature extraction

Weekend admissions and outcomes in patients with pneumonia: a systematic review and meta-analysis

BackgroundTo document pooled evidence on the association between weekend hospital admissions and the potential risks of mortality, intensive care requirements, and readmission among patients with pneumonia.MethodsWe performed a systematic search across the PubMed, EMBASE, and Scopus databases. We collected observational studies exploring the association between weekend admissions and outcomes of interest in patients with pneumonia. To analyze the data, we used a random effects model and expressed the effect sizes as pooled odds ratios (ORs) accompanied by their respective 95% confidence intervals (CIs).ResultsThe analysis comprised data from 13 retrospective studies. Compared to patients admitted on weekdays, those admitted during the weekend had a non-statistically significant marginally higher risk of in-hospital mortality (OR, 1.02; 95% CI, 1.00, 1.04) but similar 30-day mortality after admission (OR, 1.03; 95% CI, 0.97, 1.10), and similar risks of admission to intensive care unit (OR, 1.04; 95% CI, 0.98, 1.11) and re-admission (OR, 0.85; 95% CI, 0.65–1.12).ConclusionOur findings do not support the presence of a “weekend effect” in patients with pneumonia.Systematic review registrationPROSPERO, identifier CRD42023425802, https://www.crd.york.ac.uk/prospero/

A clinical Pseudomonas juntendi strain with blaIMP−1 carried by an integrative and conjugative element in China

ObjectiveTo precisely determine the species of a carbapenem-resistant Pseudomonas strain 1809276 isolated from the urine of a Chinese patient and analyze its integrative and conjugative element (ICE) 1276 formation mechanism.MethodsSingle-molecule real-time (SMRT) sequencing was carried out on strain 18091276 to obtain the complete chromosome and plasmid (pCN1276) sequences, and average nucleotide identity (ANI) was used for precise species identification. The ICEs in GenBank with the same integrase structure as ICE 1276 were aligned. At the same time, the transfer ability of blaIMP−1 and the antibiotic sensitivity of Pseudomonas juntendi 18091276 were tested.ResultsThis bacterium was P. juntendi, and its drug resistance mechanism is the capture of the accA4' gene cassette by the Tn402-like type 1 integron (IntI1-blaIMP−1) to form In1886 before its capture by the ΔTn4662a-carrying ICE 1276. The acquisition of blaIMP−1 confers carbapenem resistance to P. juntendi 18091276.ConclusionThe formation of blaIMP−1-carrying ICE 1276, its further integration into the chromosomes, and transposition and recombination of other elements promote bacterial gene accumulation and transmission

Automated Patterning and Probing with Multiple Nanoscale Tools for Single-Cell Analysis

The nano-manipulation approach that combines Focused Ion Beam (FIB) milling and various imaging and probing techniques enables researchers to investigate the cellular structures in three dimensions. Such fusion approach, however, requires extensive effort on locating and examining randomly-distributed targets due to limited Field of View (FOV) when high magnification is desired. In the present study, we present the development that automates ‘pattern and probe’ particularly for single-cell analysis, achieved by computer aided tools including feature recognition and geometric planning algorithms. Scheduling of serial FOVs for imaging and probing of multiple cells was considered as a rectangle covering problem, and optimal or near-optimal solutions were obtained with the heuristics developed. FIB milling was then employed automatically followed by downstream analysis using Atomic Force Microscopy (AFM) to probe the cellular interior. Our strategy was applied to examine bacterial cells (Klebsiella pneumoniae) and achieved high efficiency with limited human interference. The developed algorithms can be easily adapted and integrated with different imaging platforms towards high-throughput imaging analysis of single cells

The Glass-Transition Temperature of Supported PMMA Thin Films with Hydrogen Bond/Plasmonic Interface

The interfacial effect is one of the significant factors in the glass-transition temperature (Tg) of the polymeric thin film system, competing against the free surface effect. Herein, the Tgs of poly (methyl methacrylate) (PMMA) films with different thicknesses and substrates are studied by fluorescence measurements, focusing on the influence of interfacial effects on the Tgs. The strong interaction between PMMA and quartz substrate leads to increased Tgs with the decreased thickness of the film. The plasmonic silver substrate causes enhanced fluorescence intensity near the interface, resulting in the delayed reduction of the Tgs with the increasing film thickness. Moreover, as a proof of the interface-dependent Tgs, hydrogen bonds of PMMA/quartz and molecules orientation of PMMA/silver are explored by the Raman spectroscopy, and the interfacial interaction energy is calculated by the molecular dynamics simulation. In this study, we probe the inter-relationship between the interfacial interactions arising from the different substrates and the Tg behavior of polymer thin films

Effect of surgical approach on the treatment of Morton’s neuroma: a systematic review and meta-analysis

Abstract Background Surgical resection of Morton’s neuroma includes dorsal and plantar approaches. However, there is no consensus on the choice of approach in clinic. The purpose of this study was to conduct a systematic review and meta-analysis to compare the surgical results of dorsal and plantar approaches. Methods The literatures of PubMed, Cochrane library, Embase and Web of Science were searched on April 26th, 2023. A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The data were extracted after screening the literature and evaluating the quality of the methodology included in the study. The RevMan5.4 software was used to analyze and calculate the OR value and 95% confidence interval. Results A total of 7 randomized controlled trials and comparative studies were published, of which only 5 were included. There were 158 feet via plantar approach (plantar group, PG) and 189 via dorsal approach (dorsal group, DG). There was no significant difference between PG and DG in overall adverse events, sensory problems, incision infection and deep vein thrombosis (p > 0.05). In terms of scar problems, PG showed more than DG (OR, 2.90[95%CI, 1.40 to 5.98]; p = 0.004). Other outcome indicators such as visual analogue scale (VAS) scores and American Orthopedic Foot and Ankle Society (AOFAS) scores were difficult to be included in the comparison. Conclusions Based on the relatively low quality and small amount of available evidence, the meta-analysis conducted produces a hypothesis that the frequency of adverse events in surgical treatment of Morton’s neuroma, dorsal approach and plantar approach may be the same, but the types are different. More high-level evidence is needed to further verify this hypothesis

TrmFO, a Fibronectin-Binding Adhesin of Mycoplasma bovis

Mycoplasma bovis is an important pathogenic mycoplasma, causing the cattle industry serious economic losses. Adhesion is a crucial step in the mycoplasmas’ infection and colonization process; fibronectin (Fn), an extracellular matrix glycoprotein, is a molecular bridge between the bacterial adhesins and host cell receptors. The present study was designed to characterize the Fn-binding ability of methylenetetrahydrofolate-tRNA-(uracil-5-)-methyltransferase (TrmFO) and its role in M. bovis cytoadherence. The trmFO (MBOV_RS00785) gene was cloned and expressed in E. coli BL21, and polyclonal antibodies against the recombinant TrmFO (rTrmFO) were raised in rabbits. Immunoblotting demonstrated that TrmFO was an immunogenic component, and the TrmFO expression was conserved in different M. bovis isolates. The mycoplasmacidal assay further showed that in the presence of complement, rabbit anti-recombinant TrmFO serum exhibited remarkable mycoplasmacidal efficacy. TrmFO was detected in both the M. bovis membrane and cytoplasm. By ligand dot blot and enzyme-linked immunosorbent assay (ELISA) binding assay, we found that rTrmFO bound Fn in a dose-dependent manner. Immunostaining visualized by confocal laser scanning microscopy showed that rTrmFO had capacity to adhere to the embryonic bovine lung (EBL) cells. In addition, the adhesion of M. bovis and rTrmFO to EBL cells could be inhibited by anti-rTrmFO antibodies. To the best of our knowledge, this is the first report to characterize the Fn-binding ability of TrmFO and its role in the bacterial adhesion to host cells