SalK/SalR, a Two-Component Signal Transduction System, Is Essential for Full Virulence of Highly Invasive Streptococcus suis Serotype 2

BACKGROUND: Streptococcus suis serotype 2 (S. suis 2, SS2) has evolved into a highly infectious entity, which caused the two recent large-scale outbreaks of human SS2 epidemic in China, and is characterized by a toxic shock-like syndrome. However, the molecular pathogenesis of this new emerging pathogen is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: 89K is a newly predicted pathogenicity island (PAI) which is specific to Chinese epidemic strains isolated from these two SS2 outbreaks. Further bioinformatics analysis revealed a unique two-component signal transduction system (TCSTS) located in the candidate 89K PAI, which is orthologous to the SalK/SalR regulatory system of Streptococcus salivarius. Knockout of salKR eliminated the lethality of SS2 in experimental infection of piglets. Functional complementation of salKR into the isogenic mutant DeltasalKR restored its soaring pathogenicity. Colonization experiments showed that the DeltasalKR mutant could not colonize any susceptible tissue of piglets when administered alone. Bactericidal assays demonstrated that resistance of the mutant to polymorphonuclear leukocyte (PMN)-mediated killing was greatly decreased. Expression microarray analysis exhibited a transcription profile alteration of 26 various genes down-regulated in the DeltasalKR mutant. CONCLUSIONS/SIGNIFICANCE: These findings suggest that SalK/SalR is requisite for the full virulence of ethnic Chinese isolates of highly pathogenic SS2, thus providing experimental evidence for the validity of this bioinformatically predicted PAI

A Smart Exhibition Platform of Power Measurement Vehicle based on the GIS and GPS Techniques

A kind of embedded, GIS and GPS centered, smart exhibition platform of power system engineering vehicle were developed in this paper. The system was composed by three parts, which is the vehicle terminal, the server software platform and the monitoring center. The Windows NT Server, Oracle software and VB.NET were used as the developing tools. Together with the GIS and GPS technologies, the N-tier Architecture and the reusable component technology were used to display the real time information of engineering vehicle. The trial operation in the Chongqing Power Electrical Corp. indicated that, with the special structure, the application program development has no connection with the software platform, the heterogeneous database interaction is very convenient, and the system is open, safety and efficient. This smart exhibition system enhanced the dispatching management on the power measurement engineering vehicle, improved the reaction ability on the sudden accident of power equipment and power measurement equipment, and played an important role in the safety maintenance of power grid as well as the loss decrease caused by the measurement errors of power measurement equipment

A Sparse Recovery Algorithm Based on Arithmetic Optimization

At present, the sparse recovery problem is mainly solved by convx optimization algorithm and greedy tracking method. However, the former has defects in recovery efficiency and the latter in recovery ability, and neither of them can obtain effective recovery under large sparsity or small observation degree. In this paper, we propose a new sparse recovery algorithm based on arithmetic optimization algorithm and combine the ideas of greedy tracking method. The proposed algorithm uses arithmetic optimization algorithm to solve the sparse coefficient of the signal in the transform domain, so as to reconstruct the original signal. At the same time, the greedy tracking technique is combined to design the initial position of the operator before solving, so that it can be searched better. Experiments show that compared with other methods, the proposed algorithm can not only obtain more effective recovery, but also run faster under general conditions of observation number. At the same time, It can also recover the signal better in the presence of noise

A Smart Exhibition Platform of Power Measurement Vehicle based on the GIS and GPS Techniques

A kind of embedded, GIS and GPS centered, smart exhibition platform of power system engineering vehicle were developed in this paper. The system was composed by three parts, which is the vehicle terminal, the server software platform and the monitoring center. The Windows NT Server, Oracle software and VB.NET were used as the developing tools. Together with the GIS and GPS technologies, the N-tier Architecture and the reusable component technology were used to display the real time information of engineering vehicle. The trial operation in the Chongqing Power Electrical Corp. indicated that, with the special structure, the application program development has no connection with the software platform, the heterogeneous database interaction is very convenient, and the system is open, safety and efficient. This smart exhibition system enhanced the dispatching management on the power measurement engineering vehicle, improved the reaction ability on the sudden accident of power equipment and power measurement equipment, and played an important role in the safety maintenance of power grid as well as the loss decrease caused by the measurement errors of power measurement equipment

Design and Realization of a Condition Management System for the Gateway Electrical Energy Metering Device

With the construction of firm and intelligent power grid in China, it is difficult for the traditional management method of electrical energy metering device to meet the prospecting requirements. Using the computer and internet techniques to realize the information and intelligentization of the electrical energy metering management has become a necessary guarantee of improving power supply ability, marketing control, and customer service. This paper introduced a kind of large and intelligent condition management system of the gateway electrical energy metering device. The key technologies and realize process were analyzed. Moreover, a detailed description of the application modules such as the GIS smart display of metering point, the condition management of metering devices and the visual monitoring of metering point was presented. The trial operation in the selected transformer substations and the power stations of Chongqing Power Electrical Corp. indicated that, the condition management system is very open, safety and efficient. According to the data exchange with the production and scheduling platform, the system improved the efficient operation of the electrical energy metering devices. Meanwhile, combined with the real-time visual monitoring, the condition management system improved the prevention ability of electricity filching, realized the unified automatic large-scale management of electrical energy metering devices

重离子诱变酵母培养基的优化与研究

<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">利用~(12)C~(6+)离子诱变技术对面包酵母菌种进行诱变,得到一株粗蛋白含量达到55%以上的菌株,借助Minitab16.0,采用Plackett-Burman实验设计法及响应面分析法,对诱变后面包酵母菌发酵培养基的成分进行了优化,得到3个最为显著的主要影响因子:葡萄糖、酵母抽提物和硫酸镁。利用最陡爬坡实验逼近最大响应区域后,利用Box-Behnken实验设计及响应面分析法进行回归分析。通过求解回归方程,得到优化发酵的条件为,葡萄糖:11.03 g/L、酵母抽提物:6.53 g/L、硫酸镁:5.59 g/L。面包酵母生物量为4.84 g/L,相比未进行优化时的生物量提高了15%。</span><span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">A mutant bread yeast strain with high protein content of 55% was gained by use of ~(12)C~(6+) ions. The MINITAB 16.0 software, Plackett-Burman experimental design and response surface methodology were applied to optimize the culture medium for the irradiated yeast. The most important three factors which influenced the culture results were identified as glucose, magnesium sulphate and yeast extract. The path of the steepest ascent was undertaken to approach the optimal region of the three significant factors. Box-Behnken design and response surface methodology were used for the regression analysis. Finally, the optimal fermentation conditions were identified as glucose 11.03 g/L, yeast extract 6.53 g/L and magnesium sulphate 5.59 g/L by the regression analysis. It was found that the biomass of the bread yeasts reached 4.84 g/L and increased by 15% compared to original conditions.</span

The Reduced Oligomerization of MAVS Mediated by ROS Enhances the Cellular Radioresistance

Although the mitochondrial antiviral signaling protein (MAVS), located in the mitochondrial outmembrane, is believed to be a signaling adaptor with antiviral feature firstly, it has been shown that suppression of MAVS enhanced radioresistance. The mechanisms underlying this radioresistance remain unclear. Our current study demonstrated that knockdown of MAVS alleviated the radiation-induced mitochondrial dysfunction (mitochondrial membrane potential disruption and ATP production), downregulated the expressions of proapoptotic proteins, and reduced the generation of ROS in cells after irradiation. Furthermore, inhibition of mitochondrial ROS by the mitochondria-targeted antioxidant MitoQ reduced amounts of oligomerized MAVS after irradiation compared with the control group and also prevented the incidence of MN and increased the survival fraction of normal A549 cells after irradiation. To our knowledge, it is the first report to indicate that MAVS, an innate immune signaling molecule, is involved in radiation response via its oligomerization mediated by radiation-induced ROS, which may be a potential target for the precise radiotherapy or radioprotection

Effect of Na2CO3 on the Microstructure and Macroscopic Properties and Mechanism Analysis of PVA/CMC Composite Film

Polyvinyl alcohol (PVA)/carboxyl methyl cellulose sodium (CMC)/Na2CO3 composite films with different contents of Na2CO3 were prepared by blending and solution-casting. The effect of Na2CO3 on the microstructure of PVA/CMC composite film was analyzed by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). Its macroscopic properties were analyzed by water sorption, solubility, and dielectric constant tests. The results show that the microstructure of PVA/CMC/Na2CO3 composite films was different from that of PVA and PVA/CMC composite films. In addition, compared to PVA and PVA/CMC composite films, the water sorption of PVA/CMC/Na2CO3 composite films relatively increased, the solubility in water significantly decreased, and the dielectric properties significantly improved. All these results indicate that the hydrogen bonding interaction between PVA and CMC increased and the crystallinity of PVA decreased after the addition of Na2CO3. This was also a direct factor leading to increased water sorption, decreased solubility, and enhanced dielectric properties. The reaction mechanism of PVA, CMC, and Na2CO3 is proposed to further evaluate the effect of Na2CO3 on the microstructure and macroscopic properties of PVA/CMC/Na2CO3 composite films

Cd resistant characterization of mutant strain irradiated by carbon-ion beam

Heavy metal pollution is harmful to the environment and to human health. Resistant strains can grow in adverse conditions and store heavy metals to reduce their damage. The Cd2+ resistant mutant strain C2, which was irradiated by the C-12(6+) beams, can grow in Cd medium ranging from 20 to 100 mg L-1 when compared with the original strain. Attempting to discern the cause of the resistance, the phenotype and antioxidant defense system were analyzed. SEM images showed that when exposed to Cd2+, gaps on the cell surface were filled with a complex granular compound. FT-IR demonstrated that the alcoholic hydroxyl group, amino, and amide groups combined with ions. Moreover, responses of antioxidant defense system were different in the Cd2+ groups. The expression of SOD peaked at 24 h in high concentrations of Cd2+; the content of GSH increased gradually and was significantly affected by cultivation time. The MDA and CAT had the strongest response to 20 mg L-1 Cd2+ and the related metabolic pathway of CAT might play a key role in the resistance to high concentrations of Cd2+, The result indicated that the applicability of C2 could provide potential biotechnology for treatment of waste-waters and soils with Cd pollutions.</p