Pharmacokinetic/pharmacodynamic integration of tilmicosin against Pasteurella multocida in a piglet tissue cage model

Tilmicosin is a semi-synthetic macrolide for veterinary use with strong antibacterial effect on respiratory bacteria. In this study, the pharmacokinetic/pharmacodynamic (PK/PD) integration of tilmicosin against Pasteurella multocida (P. multocida) was evaluated by establishing a piglet tissue cage infection model. Concentration of tilmicosin and bacterial numbers of P. multocida in the tissue-cage fluid were monitered. After the population of P. multocida was equal to or greater than 107 CFU/mL in a tissue cage, piglets received an oral administration of tilmicosin at a dose of 30, 40, 50, and 60 mg/kg b.w., once daily for 3 days, respectively. Bacteria were counted every 24 h after drug administration and at 48 and 72 h after the last administration. A sigmoidal Emax model was used to fit the relationship between PK/PD parameters and the antibacterial effect. AUC24h/MIC was the best PK/PD index that correlated with effectiveness of tilmicosin against P. multocida. The magnitude of AUC24h/MIC required for continuous 1/3-log, 1/2-log, and 3/4-log reductions were 19.65 h, 23.86 h, and 35.77 h, respectively, during each 24 h treatment period. In this study, when the dosage was >50 mg/kg, the AUC24h/MIC was still >35.77 h in the period of 24–48 h after the last administration due to the slow elimination, that is, tilmicosin exhibited a potent antibacterial effect against P. multocida after three successive daily administrations. The data provide meaningful guidance to optimize regimens of tilmicosin to treat respiratory tract infections caused by P. multocida

LdsConv : learned depthwise separable convolutions by group pruning

Standard convolutional filters usually capture unnecessary overlap of features resulting in a waste of computational cost. In this paper, we aim to solve this problem by proposing a novel Learned Depthwise Separable Convolution (LdsConv) operation that is smart but has a strong capacity for learning. It integrates the pruning technique into the design of convolutional filters, formulated as a generic convolutional unit that can be used as a direct replacement of convolutions without any adjustments of the architecture. To show the effectiveness of the proposed method, experiments are carried out using the state-of-the-art convolutional neural networks (CNNs), including ResNet, DenseNet, SE-ResNet and MobileNet, respectively. The results show that by simply replacing the original convolution with LdsConv in these CNNs, it can achieve a significantly improved accuracy while reducing computational cost. For the case of ResNet50, the FLOPs can be reduced by 40.9%, meanwhile the accuracy on the associated ImageNet increases

Plateau pika fecal microbiota transplantation ameliorates inflammatory bowel disease manifestations in a mouse model of colitis

Inflammatory bowel disease (IBD) is a serious global public health concern. Although the pathogenesis of the disease is currently unknown, it has been reported to be associated with both intestinal microbiota and inflammatory mediators. There is evidence suggesting that the feces of the Plateau pika is useful for treating gastrointestinal injuries and pain. Although fecal microbiota transplantation is highly efficacious intervention for IBD prevention, however, potential the transfer of pathogenic microbes or toxic substances is potentially hazardous. Fortunately, micropore filtering of the donor feces can minimize the risk of bacterial infection allowing retention of the therapeutic effects of the residual bacteriophages. Here, we demonstrated that Plateau pika feces not only alleviated the IBD symptoms but also promoted optimal structure and composition of the intestinal microbiota. Additionally, Plateau pika feces transfer also enhanced phenotypic features, such as, body-weight, disease activity index, and histological scores. In conclusion, Plateau pika feces was found to protect mice against colitis induced by dextran sodium sulfate by reducing inflammation and regulating microbial dysbiosis. These findings suggest the potential of Plateau pika feces as an alternative therapy for IBD

Influence of Bonding Delaminations on The Electromechanical Admittance (EMA) of a Multi-element Piezoelectric Transducer

The transducer is an essential part of all ultrasonic systems used for applications such as medical diagnostics, therapy, nondestructive evaluation, cleaning or other purposes because its performance is crucial for that of the entire device. Its health condition is thus vital to ensure proper operation. Defects within constitutive elements or loss of adhesion between them can significantly reduce the transducer performance. The objective of this work is to determine procedures to monitor the behavior of a multi-element probe during its lifetime and detect degradations before they significantly affect the performance of the system. To achieve this, electromechanical admittance-based (EMA-based) method is investigated numerically and experimentally. A simplified multi-element transducer element consisting of a piezoceramic bar, a bonding layer and a backing is studied and the influence of bonding delamination on EMA is investigated. This study considers two different types of delamination, which are named respectively ”side” (from one side and expands towards the other) and ”center” (from the center and expands outwards). First, three dimensional numerical models based on the finite element method are developed. Secondly, transducers with and without defects are mounted using 3D-printed backings and matching layers, and finally measurements are conducted using an impedance analyzer. Experimental results are found to be in good agreement with numerical ones and it is shown that changes in EMA could allow early detection of delamination defects in an ultrasound probe

Influence of Bonding Delaminations on The Electromechanical Admittance (EMA) of a Single-element Piezoelectric Transducer

International audienceThe transducer is an essential part of all ultrasonic systems used for applications such as medical diagnostics, therapy, nondestructive evaluation, cleaning or other purposes because its health condition is vital to their proper operation. Defects within the active element, backing or other constitutive elements, loss of adhesion between layers can significantly weaken the performance of a transducer. The objective of this work is to determine procedures to monitor the behavior of a single-element probe during its lifetime and detect degradations before they significantly affect the performance of the system. To achieve this, electromechanical admittance-based (EMA-based) method is envisaged numerically and experimentally. A simplified single-element transducer consisting of a piezoceramic disk, a bonding layer and a backing is studied and the influence of bonding delamination on EMA is investigated. This study considers three different types of delaminations, which are named respectively ?center? (circular delamination from the center of the disc towards the peripheric zone), ?peripheric? (annular delamination from the peripheric zone towards the center) and ?wedge? (delamination from the center to the outside with a given angle). First, a numerical model based on the finite element method is developed. A two-dimensional (2D) finite element analysis is implemented for the first two types of delaminations, taking advantage of their axisymmetric structure, and ?wedge? delamination is modeled in three dimensions (3D). Secondly, transducers with different shapes of 3D printed backings are mounted and experiments are conducted using an impedance analyzer. Experimental results are found to be in good agreement with numerical solutions and it is shown that changes in EMA could allow early detection of delaminations in an ultrasound probe

Modeling and Experimental Characterization of Bonding Delaminations in Single-Element Ultrasonic Transducer

International audienceUltrasonic transducers performance can be seriously deteriorated by loss of adhesion between some constitutive elements such as the active element, the backing, or the matching layer. In the present work, the influence of bonding delaminations on the performance of a single-element ultrasonic transducer, which is composed of a piezoelectric disk, a backing, and a matching layer, is studied numerically and experimentally. Based on the positions between layers, two cases, i.e., delaminations between ceramic and backing or between ceramic and matching layer, are considered. Each case involves three different types of delaminations, which are marked as delamination type (DT)-I, II, and III. DT-I, a circular shape delamination, starts from the center and expands towards the peripheric zone; DT-II, an annular shape delamination, starts from the peripheric zone and expands towards the center; DT-III is a sector shape delamination with a given angle. The numerical simulations are performed by the finite element method and the influence of delaminations on the electromechanical admittance (EMA) of the transducer is investigated. 3D printed backings and matching layers are mounted on a PZT sample to assemble delaminated single-element transducers. An impedance analyzer is used for experimental measurements. Comparison between numerical and experimental results shows a reasonable agreement making changes in EMA an interesting indicator to inform about the occurrence and severity of delaminations in a single-element ultrasonic transducer

An Original Two-Dimensional Analytical Model for Investigating Coupled Vibrations of Finite Piezoelectric Resonators

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Accurate coupled vibration analysis of a piezoelectric array element by the superposition method

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Accurate coupled vibration analysis of a piezoelectric ceramic cylinder by the superposition method

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Health Monitoring of Single-element Piezoelectric Transducer Using Its Electromechanical Admittance

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