The prevalence of non-GII.4 norovirus genotypes in acute gastroenteritis outbreaks in Jinan, China.

Noroviruses (NoVs) are the leading cause of acute viral gastroenteritis outbreaks. From June 2015 to March 2017, fifteen outbreaks of acute gastroenteritis (AGE) were reported to the Jinan Center for Disease Control and Prevention in China. To identify the circulating NoV genotypes associated with outbreaks in Jinan, China, 414 specimens from the 15 outbreaks were collected and analyzed for the causative viruses, and phylogenetic analysis was performed on the NoV-positive strains. The NoV detection rate was 57.5% (238/414), and a total of 14 outbreaks were caused by NoVs (eight by infection with genogroup II (GII), five by mixed infection with GI and GII, and one by mixed infection with GII and rotavirus (RoV)-A). A total of 75 NoV sequences were obtained from 13 NoV-positive outbreaks and classified into seven genotypes (38 GII.17, 13 GII.2, 4 GII.3, 4 GII.1, 10 GI.6, 5 GI.5 and 1 GI.3), while GII.4 was not identified. The most prevalent genotype changed yearly during the 2015-2017 period. Phylogenetic analysis demonstrated that these NoV genotypes had high homology with the strains circulating worldwide, especially strains from Asian countries and cities. Our study illustrated that multiple non-GII.4 NoV genotypes were prevalent in outbreaks of AGE in Jinan, China. Year-round surveillance of multiple NoV genotypes could help health authorities reduce the impact of NoV outbreaks on public health

Etiology of Multiple Non-EV71 and Non-CVA16 Enteroviruses Associated with Hand, Foot and Mouth Disease in Jinan, China, 2009-June 2013.

Hand, foot, and mouth disease (HFMD) is an infectious disease caused by human enterovirus 71 (EV71), coxsackievirus A16 (CVA16) and other enteroviruses. It is of interest that other enteroviruses associated with HFMD in Jinan have been rarely reported. The aim of the present study is to detect and characterize the circulating serotypes of non-EV71 and non-CVA16 enteroviruses associated with HFMD in Jinan city, Shandong province, China. A total of 400 specimens were collected from clinically diagnosed HFMD cases in Jinan from January 2009 to June 2013. All specimens were infected with non-EV71 and non-CVA16 enteroviruses previously confirmed by RT-PCR or real-time PCR according to the protocols at that time. The GeXP-based multiplex RT-PCR assay (GeXP assay) was performed to investigate the pathogen spectrum of 15 enteroviruses (coxsackieviruses A4, A5, A6, A9, A10, A16; coxsackieviruses B1, B3, B5; Echoviruses 6, 7, 11, 13, 19 and EV71) infections associated with HMFD. For GeXP assay negative samples, reverse transcription nested PCR (nested RT-PCR) based on the 5' -untranslated region (5'- UTR) sequence and phylogenetic analysis were conducted to further explore the etiology of multiple enteroviruses. The results showed that a total of twenty serotypes of enteroviruses (including EV71 and CVA16) were identified by GeXP assay and nested RT-PCR. The most circulating twelve serotypes of enteroviruses with HFMD in Jinan from 2009 to June 2013 were EV71, CVA16, CVA10, CVA6, CVA12, CVA2, Echo3, CVA4, CVA9, CVB1, CVB3 and Echo6. CVA10 and CVA6 were the most prevalent pathogens other than EV71 and CVA16 in Jinan and their most prevalent seasons were spring and summer, and a slight increase was observed in autumn and early winter. It should be noted that mixed-infections were identified by GeXP assay and the phylogenetic tree clearly discriminated the multiple pathogens associated with HFMD. Our results thus demonstrate that there was a clear lack of a reliable testing method for EV71 and CVA16 and multiple non-EV71 and non-CVA16 enteroviruses associated with HFMD were present in Jinan. The GeXP assay combined with nested RT-PCR based on 5'-UTR region could meet the need for the national surveillance of multiple enteroviruses or the investigation of epidemic outbreaks triggered by enteroviruses in the future

Study of the Optimization of Rail Pressure Characteristics in the High-Pressure Common Rail Injection System for Diesel Engines Based on the Response Surface Methodology

This paper establishes a mathematical model of the high-pressure common rail injection system used in diesel engines according to the parameters of its key components, and AMESim 2020 software was used to establish a simulation model of the common rail injection system used in diesel engines. The simulation model mainly includes a high-pressure oil pump model, a common rail pipe model, and a model of four injectors. This paper also describes an experimental analysis of the accuracy of the established simulation model. Through a simulation analysis of the system rail’s pressure fluctuation and pressure characteristics, it was concluded that the length of the common rail pipe, the diameter of the common rail pipe, and the inner diameter of the high-pressure fuel pipes are important influencing parameters for the rail pressure characteristics of the system. In this study, according to the original common rail pipe and high-pressure fuel pipe model, a response surface methodology was used to optimize and analyze the parameters of the common rail pipe and high-pressure fuel pipes, and the optimal size parameters for the common rail pipe and high-pressure fuel pipes were obtained with the minimum rail pressure fluctuations and the average rail pressure setpoint. After the optimization, the pressure for the common rail pipe of the high-pressure common rail system was increased by 0.82%, the pressure fluctuation was reduced by 21.66%, the injection pressure was increased by 1.15%, the single injection volume was increased by 0.86%, and its fuel injection characteristics were significantly improved

Monthly distribution of non-EV71 and non-CVA16 enterovirus serotypes during 2009 to June 2013 in Jinan, China.

<p>Monthly distribution of non-EV71 and non-CVA16 enterovirus serotypes during 2009 to June 2013 in Jinan, China.</p

Monthly distribution of CVA6 associated with HFMD during 2009 to June 2013 in Jinan, China.

<p>Monthly distribution of CVA6 associated with HFMD during 2009 to June 2013 in Jinan, China.</p

The enterovirus serotypes identified in hand-foot-mouth disease during 2009 to June 2013, in Jinan, China.

<p>The enterovirus serotypes identified in hand-foot-mouth disease during 2009 to June 2013, in Jinan, China.</p

Monthly distribution of CVA10 associated with HFMD during 2009 to June 2013 in Jinan, China.

<p>Monthly distribution of CVA10 associated with HFMD during 2009 to June 2013 in Jinan, China.</p

Phylogenetic analysis based on the 5’-UTR region of HFMD cases during 2009 to June 2013 in Jinan, China.

<p>A total of 29 representative sequences (representing 12 serotypes) from this study and 12 reference strains worldwide were used to build the tree. Jinan sequences were labeled by black solid dot. Abbreviations: JN, Jinan; CHN, China.</p