The two-component system CpxAR is required for the high potassium stress survival of Actinobacillus pleuropneumoniae

IntroductionActinobacillus pleuropneumoniae is an important respiratory pathogen, which can cause porcine contagious pleuropneumonia and lead to great economic losses to worldwide swine industry. High potassium is an adverse environment for bacteria, which is not conducive to providing turgor pressure for cell growth and division. Two-component system CpxAR is an important regulatory system of bacteria in response to environmental changes, which is involved in a variety of biological activities, such as antibiotic resistance, periplasmic protein folding, peptidoglycan metabolism and so on.MethodsHowever, little is known about the role of CpxAR in high potassium stress in A. pleuropneumoniae. Here, we showed that CpxAR is critical for cell division of A. pleuropneumoniae under high potassium (K+) stress.ResultsqRT-PCR analysis found that CpxAR positively regulated the cell division genes ftsEX. In addition, we also demonstrated that CpxR-P could directly bind the promoter region of the cell division gene ftsE by EMSA.DiscussionIn conclusion, our results described a mechanism where CpxAR adjusts A. pleuropneumoniae survival under high-K+ stress by upregulating the expression of the cell division proteins FtsE and FtsX. These findings are the first to directly demonstrate CpxAR-mediated high-K+ tolerance, and to investigate the detailed molecular mechanism

Analysis on Electromagnetic Field of Continuous Casting Mold Including a New Integral Method for Calculating Electromagnetic Torque

Based on the Maxwell’s equations, a finite element model is established to study the characteristics of electromagnetic field in the mold of billet and bloom continuous casting with electromagnetic stirring (M-EMS). A novel integral method for calculating electromagnetic torque is proposed to evaluate the stirring intensity of stirrer. In order to verify the accuracy of the model, a well-designed electromagnetic torque detecting device is fabricated. The predicted value of electromagnetic torque and magnetic flux density are consistent with the measured data. The optimum frequency is determined by the maximal electromagnetic torque of the strand. The effect of stirring current intensity and different stirrer positions along the length of mold on the electromagnetic field has been studied numerically. The results show that the optimum frequency is smaller when the copper tube of the mold is thicker and the section size is bigger. Besides, the electromagnetic torque of the strand is a quadratic function of the running current intensity. Moreover, the installation position of stirrer strongly affects the prediction of electromagnetic field distribution, further influencing the optimum frequency and the electromagnetic torque of strand

Research on Optical and Mechanical Compatible Design Technology of Multilayer Films

The stress’s accumulation will critically affect optical device stability, leading to components’ deviation and film peeling. Stress control techniques based on strain cancelation cannot precisely match film stress, and it is difficult to reduce the total stress of multilayer film to ultra-low levels. Existing software for film system design is mainly based on 2D design concepts such as wavelength-spectrum and does not consider 3D design concepts such as wavelength-spectrum-stress, but the stress parameter plays an essential role in film performance, and it is necessary to use it as an optimization index for film design. In this paper, we introduce mechanical synchronization design into film system design. The multilayer film’s optimal structure is precisely matched by the genetic algorithm, and an ultra-low stress and wide-spectrum optical film element is developed under the dual requirements of optical performance and mechanical performance. This technique incorporates computer-aided design and automatically seeks an optimal combination of layered film nanostructures through self-compiled optical and mechanical compatible design software. While ensuring invariant optical properties, it can effectively reduce the total stress of multilayer film. This can provide a new idea for film stress control

Research on Optical and Mechanical Compatible Design Technology of Multilayer Films

The stress’s accumulation will critically affect optical device stability, leading to components’ deviation and film peeling. Stress control techniques based on strain cancelation cannot precisely match film stress, and it is difficult to reduce the total stress of multilayer film to ultra-low levels. Existing software for film system design is mainly based on 2D design concepts such as wavelength-spectrum and does not consider 3D design concepts such as wavelength-spectrum-stress, but the stress parameter plays an essential role in film performance, and it is necessary to use it as an optimization index for film design. In this paper, we introduce mechanical synchronization design into film system design. The multilayer film’s optimal structure is precisely matched by the genetic algorithm, and an ultra-low stress and wide-spectrum optical film element is developed under the dual requirements of optical performance and mechanical performance. This technique incorporates computer-aided design and automatically seeks an optimal combination of layered film nanostructures through self-compiled optical and mechanical compatible design software. While ensuring invariant optical properties, it can effectively reduce the total stress of multilayer film. This can provide a new idea for film stress control

Tunable nonlinear conductive behavior without percolation threshold and high thermal conductivity of epoxy resin/SiC ceramic foam co-continuous phase composites

Smart dielectrics with self-adaptive capabilities can exhibit desirable electric field-grading performance as the applied electric field exceeds a critical value. However, the conventional approaches to such dielectrics need heavy doping rate, which will not only increase the interface thermal resistance and limit the improvement of thermal conductivity, but also severely sacrifice the mechanical property. In this contribution, a new type of electric field-grading co-continuous phase composite (EP/SiCcf) composed of epoxy resin and SiC ceramic foam was prepared to realize tunable nonlinear conductive performance, while simultaneously improving thermal and mechanical properties. Results show that there is no percolation threshold for all EP/SiCcf composites. The volume loadings of EP/SiCcf composites range from 8.7 vol% to 15.6 vol%, while the nonlinear coefficient subjected to potential barrier height increases from 2.1 to 4.5 and the switching field tuned by barrier width decreases from 1008 kV/mm to 686 kV/mm. The EP/SiCcf40 still exhibits sharp thermal conductivity enhancement of about 1000% and glass transition temperature enhancement of 10.8 °C. The surface temperature fluctuation over time during heating and cooling has illustrated the prospective application of thermal management capability. In addition, the dynamic mechanical analysis reveals that all EP/SiCcf composites have the significantly improved storage modulus and crosslinking density ascribed to the intact SiC skeleton. The novel co-continuous phase composite provides a new approach for global enhancement of smart dielectric composites in potential applications.This work was supported by the National Natural Science Foundation of China (No. 51977084)

Image_1_The two-component system CpxAR is required for the high potassium stress survival of Actinobacillus pleuropneumoniae.tif

IntroductionActinobacillus pleuropneumoniae is an important respiratory pathogen, which can cause porcine contagious pleuropneumonia and lead to great economic losses to worldwide swine industry. High potassium is an adverse environment for bacteria, which is not conducive to providing turgor pressure for cell growth and division. Two-component system CpxAR is an important regulatory system of bacteria in response to environmental changes, which is involved in a variety of biological activities, such as antibiotic resistance, periplasmic protein folding, peptidoglycan metabolism and so on.MethodsHowever, little is known about the role of CpxAR in high potassium stress in A. pleuropneumoniae. Here, we showed that CpxAR is critical for cell division of A. pleuropneumoniae under high potassium (K+) stress.ResultsqRT-PCR analysis found that CpxAR positively regulated the cell division genes ftsEX. In addition, we also demonstrated that CpxR-P could directly bind the promoter region of the cell division gene ftsE by EMSA.DiscussionIn conclusion, our results described a mechanism where CpxAR adjusts A. pleuropneumoniae survival under high-K+ stress by upregulating the expression of the cell division proteins FtsE and FtsX. These findings are the first to directly demonstrate CpxAR-mediated high-K+ tolerance, and to investigate the detailed molecular mechanism.</p

Data_Sheet_1_The two-component system CpxAR is required for the high potassium stress survival of Actinobacillus pleuropneumoniae.ZIP

IntroductionActinobacillus pleuropneumoniae is an important respiratory pathogen, which can cause porcine contagious pleuropneumonia and lead to great economic losses to worldwide swine industry. High potassium is an adverse environment for bacteria, which is not conducive to providing turgor pressure for cell growth and division. Two-component system CpxAR is an important regulatory system of bacteria in response to environmental changes, which is involved in a variety of biological activities, such as antibiotic resistance, periplasmic protein folding, peptidoglycan metabolism and so on.MethodsHowever, little is known about the role of CpxAR in high potassium stress in A. pleuropneumoniae. Here, we showed that CpxAR is critical for cell division of A. pleuropneumoniae under high potassium (K+) stress.ResultsqRT-PCR analysis found that CpxAR positively regulated the cell division genes ftsEX. In addition, we also demonstrated that CpxR-P could directly bind the promoter region of the cell division gene ftsE by EMSA.DiscussionIn conclusion, our results described a mechanism where CpxAR adjusts A. pleuropneumoniae survival under high-K+ stress by upregulating the expression of the cell division proteins FtsE and FtsX. These findings are the first to directly demonstrate CpxAR-mediated high-K+ tolerance, and to investigate the detailed molecular mechanism.</p