A New Strategy for Disc Cutter Wear Status Perception Using Vibration Detection and Machine Learning.

Carrying out status monitoring and fault-diagnosis research on cutter-wear status is of great significance for real-time understanding of the health status of Tunnel Boring Machine (TBM) equipment and reducing downtime losses. In this work, we proposed a new method to diagnose the abnormal wear state of the disc cutter by using brain-like artificial intelligence to process and analyze the vibration signal in the dynamic contact between the disc cutter and the rock. This method is mainly aimed at realizing the diagnosis and identification of the abnormal wear state of the cutter, and is not aimed at the accurate measurement of the wear amount. The author believes that when the TBM is operating at full power, the cutting forces are very high and the rock is successively broken, resulting in a complex circumstance, which is inconvenient to vibration signal acquisition and transmission. If only a small thrust is applied, to make the cutters just contact with the rock (less penetration), then the cutters will run more smoothly and suffer less environmental interference, which would be beneficial to apply the method proposed in this paper to detect the state of the cutters. A specific example was to use the frequency-domain characteristics of the periodic vibration waveform during the contact between the cutter and the granite to identify the wear status (including normal wear state, wear failure state, angled wear failure state) of the disc cutter through the artificial neural network, and the diagnosis accuracy rate is 90%.

Schizophrenia, but not depression or bipolar affective disorder, adds additional risk of aspiration pneumonia among stroke survivors: A national cohort study in Taiwan.

OBJECTIVE: Few studies have assessed the sex-specific and age-specific risk of aspiration pneumonia (AP) in patients with stroke and evaluated whether mental disorders may increase this risk. In this population-based cohort study, we investigated the sex-specific and age-specific risk of AP in association with stroke and the joint effects of stroke and mental disorders on the risk of AP. METHODS: We included 23,288 patients with incident stroke admitted between 2005 and 2017 and 68,675 matched nonstroke controls. Information on mental disorders was obtained from medical claims data within the 3 years before the stroke incidence. Cox proportional hazards models considering death as a competing risk event were constructed to estimate the hazard ratio of AP incidence by the end of 2018 associated with stroke and selected mental disorders. RESULTS: After ≤14 years of follow-up, AP incidence was higher in the patients with stroke than in the controls (11.30/1000 vs. 1.51/1000 person-years), representing a covariate-adjusted subdistribution hazard ratio (sHR) of 3.64, with no significant sex difference. The sHR significantly decreased with increasing age in both sexes. Stratified analyses indicated schizophrenia but not depression or bipolar affective disorder increased the risk of AP in the patients with stroke. CONCLUSION: Compared with their corresponding counterparts, the patients with schizophrenia only, stroke only, and both stroke and schizophrenia had a significantly higher sHR of 4.01, 5.16, and 8.01, respectively. The risk of AP was higher in younger stroke patients than those older than 60 years. Moreover, schizophrenia was found to increase the risk of AP in patients with stroke.

Clinical Observation of Flapless Implantation in the Posterior Tooth Area under the Guidance of the Fully Guided Template.

Objective: Compared with the conventional flap implantation, the postoperative effect of flapless implantation of a single posterior tooth under the guidance of the fully guided template was observed. Materials and Methods: 67 cases were divided into the template group (n = 35) and the flap group (n = 32) according to the wishes and actual situation of the patients. In the template group, the fully guided template was made by rapid prototyping technology, and the flapless implantation was performed under the guidance of the template in the posterior tooth area. The flap group underwent routine flap implantation. After the operation, the template group took CBCT (cone beam computed tomography) again and fitted it with that before the operation. Neck deviation, apical deviation, depth deviation, and axial angle deviation in buccolingual and mesiodistal directions were measured to observe the accuracy of the fully guided template. At the same time, the postoperative reactions of the two surgical methods were compared by recording the operation time, pain degree 24 hours after the operation, swelling degree 72 hours after the operation, and postoperative satisfaction of patients. Results: Whether in buccolingual or mesiodistal directions, the maximum values of neck deviation, apical deviation, and depth deviation were less than 2 mm. The axial angle deviation was 0.07°âˆ¼5.93° in the buccolingual direction and 0°âˆ¼4.12° in the mesiodistal direction. The guiding effect of the template was relatively reliable, and the implantation site and depth were well controlled. Although there were small deviations, the accuracy of the template could meet the clinical needs. The operation time and the VAS (visual analogue scale) score 24 hours after the operation in the template group were lower than those in the flap group (P < 0.05), and the swelling degree rating 72 hours after the operation and postoperative satisfaction of the patients were better than those in the flap group (P < 0.05). Conclusion: Compared with the conventional flap implantation, the flapless implantation in the posterior tooth area under the guidance of the fully guided template could improve the accuracy of the operation, shorten the operation time, and reduce the degree of postoperative pain and swelling, which had a certain positive clinical significance.

Antimicrobial resistance of bacterial isolates from respiratory care wards in Taiwan: a horizontal surveillance study.

A horizontal surveillance study was conducted to identify common bacteria and mycobacteria from 611 respiratory aspirates and 165 urinary samples from 611 patients hospitalised at 17 respiratory care wards (RCWs) in Taiwan. Some major resistance phenotypes, including methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis, and multidrug-resistant Pseudomonas aeruginosa (MDR-PA) and Acinetobacter baumannii (MDR-AB), were identified. Pulsotypes of ESBL-producing P. mirabilis isolates were determined by pulsed-field gel electrophoresis. The prevalences of MRSA, ESBL-producing E. coli (K. pneumoniae and P. mirabilis), carbapenem-resistant (resistant to imipenem and meropenem) P. aeruginosa, MDR-PA, carbapenem-resistant A. baumannii and MDR-AB were, respectively, 86.7%, 20.0% (50.7% and 24.1%), 18.4%, 1.2%, 32.1% and 8.9% for respiratory aspirates and 100%, 25.4% (27.3% and 25.0%), 48.3%, 10.3%, 50.0% and 21.4% for catheterised urinary samples. Among the 44 respiratory isolates of P. mirabilis with an ESBL phenotype, 22 different pulsotypes (>80% identity) were identified. Among 103 isolates of mycobacteria, 90 (87.4%) belonged to rapidly growing mycobacteria and 4 (4%) were Mycobacterium tuberculosis. Among the 404 patients with available clinical information, true infections were found in 28.0%, the most prevalent of which were urinary tract infection (20.5%) and ventilator-associated pneumonia (10.9%). High prevalences of various multidrug-resistant bacteria among the respiratory and urinary tracts of patients present a clinical difficulty in choosing empirical antibiotic treatment in RCWs.