111 research outputs found

    Editorial: Campylobacter-associated food safety

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    Introduction: Campylobacteriosis is an enteric bacterial zoonotic infection caused by members of the Campylobacter genus (Kirkpatrick and Tribble, 2011). C. jejuni (> 85%) and C. coli (5–10%) are the most common species associated with the disease (Patrick et al., 2018). Ingestion of as few as 500 bacteria can cause campylobacteriosis (Robinson, 1981). Although Campylobacter typically causes self-limiting human gastroenteritis, it can lead to prolonged post-infectious complications, such as Guillain-Barré syndrome, reactive arthritis, and/or post infectious-irritable bowel syndrome (Rees et al., 1995). The treatment of campylobacteriosis poses significant economic burdens worldwide, resulting in 1.56billioninhealthcarecostsintheUSA,1.56 billion in healthcare costs in the USA, 80 million in Canada, and €2.4 billion in the European Union per year (Devleesschauwer et al., 2017). The high prevalence of Campylobacter in the agri-food system is likely a major contributing factor to the incidence of campylobacteriosis. Due to its microaerobic nature, Campylobacter can colonize the intestinal tract of food-producing animals such as poultry, cattle, sheep, and swine (Hansson et al., 2018). However, it can also survive under aerobic conditions and infect humans through the food supply chain by forming biofilms or entering the viable but non-culturable state (Lv et al., 2019; Ma et al., 2022). The main route of infection has been identified as the consumption of contaminated food commodities, such as unpasteurized dairy products, undercooked poultry meat and/or contaminated water (Silva et al., 2011). Therefore, detection, characterization, and reduction of Campylobacter in the agroecosystem are of great importance. This mini-review provides an overview of the current trends in understanding Campylobacter and its interaction with the agroecosystem. We first introduce the improved methods to detect Campylobacter in various agri-food settings. Then, the prevalence of this microbe in the agri-food system as well as its characteristics are summarized. Finally, novel control strategies of Campylobacter are summarized and discussed

    A ternary PEDOT-TiO2-reduced graphene oxide nanocomposite for supercapacitor applications

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    A ternary composite of PEDOT was prepared with TiO2 via emulsion polymerization method adjusting various weight ratios of TiO2 to PEDOT and synthesized rGO was then blended with this composite. The FTIR, UV–Vis and XRD analysis displayed characteristic features of PEDOT and TiO2. The morphology of the nano-hybrid structure was additionally investigated by SEM analysis. Pore size and surface area analysis of particles were characterized by BET method. The electrochemical analysis showed that the specific capacitance (Csp) for PEDOT-TiO2-15-rGO was 18.9 F.cm-2 at 0.1 mA g-1 current density

    Neutrino Physics with JUNO

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    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purposeunderground liquid scintillator detector, was proposed with the determinationof the neutrino mass hierarchy as a primary physics goal. It is also capable ofobserving neutrinos from terrestrial and extra-terrestrial sources, includingsupernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos,atmospheric neutrinos, solar neutrinos, as well as exotic searches such asnucleon decays, dark matter, sterile neutrinos, etc. We present the physicsmotivations and the anticipated performance of the JUNO detector for variousproposed measurements. By detecting reactor antineutrinos from two power plantsat 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4sigma significance with six years of running. The measurement of antineutrinospectrum will also lead to the precise determination of three out of the sixoscillation parameters to an accuracy of better than 1\%. Neutrino burst from atypical core-collapse supernova at 10 kpc would lead to ~5000inverse-beta-decay events and ~2000 all-flavor neutrino-proton elasticscattering events in JUNO. Detection of DSNB would provide valuable informationon the cosmic star-formation rate and the average core-collapsed neutrinoenergy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400events per year, significantly improving the statistics of existing geoneutrinosamples. The JUNO detector is sensitive to several exotic searches, e.g. protondecay via the pK++νˉp\to K^++\bar\nu decay channel. The JUNO detector will providea unique facility to address many outstanding crucial questions in particle andastrophysics. It holds the great potential for further advancing our quest tounderstanding the fundamental properties of neutrinos, one of the buildingblocks of our Universe

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30MM_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

    Two-dose varicella vaccine effectiveness in China: a meta-analysis and evidence quality assessment

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    Abstract Background The objectives of this review were to evaluate the vaccine effectiveness (VE) of the two-dose varicella vaccine for healthy children in China and explore the application of the approach of Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) in observational studies on VE. Methods We searched for observational studies on two-dose varicella VE for children in China aged 1–12 years that were published from 1997 to 2019, and assessed the quality of each study using the Newcastle Ottawa Scale (NOS). We used meta-analysis models to obtain the pooled two-dose VE, and the studies were divided into subgroups and analysed according to whether or not it was an outbreak investigation and its NOS score. The quality of evidence of VEs were rated by approach of the GRADE system. Results A total of 12 studies and 87,196 individuals were included. The pooled two-dose VE was 90% (95% confidence interval [CI]: 69–97%). The VE of outbreak studies (87% [95% CI: 76–93%]) was lower than non-outbreak studies (99% [95% CI: 98–99%]). There was no significant difference in VEs by different NOS quality. The quality of the evidence assessment of pooled two-dose VE was “low”, which was rated down by one category in limitations and publication bias respectively and rated up by two category in large effect. The quality of evidence assessment in subgroup of NOS score ≥ 7 was “moderate”. Conclusions The VE of two-dose varicella vaccine is relatively high in preventing varicella, and is recommended for countries which need further control for varicella. However, higher quality evidence is needed as a supplement for stronger recommendations. The approach of GRADE could be applied for rating the quality of evidence in observational study

    The influence of target film material and coating on neutron yield and sputtering yield

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    The long-life, high yield deuterium-deuterium (D-D) neutron tube has become one of the research hotspots. Here, deuterated polyethylene target, heavy water target and titanium target were investigated by Stopping and Range of Ions in Matter (SRIM). The calculation showed that the deuterated polyethylene target, which was a potential target material, had the highest yield at an incident energy of 120 keV. Further, considering the unfavorable factors such as impurity ions and high temperature, the coating was used to protect the target material. Diamond, boron carbide, boron nitride, silicon carbide, and aluminum carbide were selected. The simulation results showed that the diamond composite deuterated polyethylene film had the best sputtering resistance, and the aluminum nitride composite heavy water target film had the lowest sputtering yield. The two coating materials shield the target, reduced the energy loss of incident ions, and provided a new method for the research of high yield and long life neutron tube

    Outbreak of measles among persons with secondary vaccine failure, China, 2018

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    Although the incidence of measles has been dramatically reduced by the highly effective measles vaccine, cases of measles and outbreaks continue to occur in vaccinated population because of immunization failure. We report on an outbreak in which two cases had previous evidence of measles immunity and then one of them transmitted measles infection to an unvaccinated contact. The cases and contacts exposed during the outbreak were investigated. Clinical information and epidemiological information were obtained. Serum samples were collected for measles-specific immunoglobulin M (IgM), immunoglobulin G (IgG) and IgG avidity. Throat swabs were obtained to test for measles virus RNA. Two measles cases (case 1 and case 2) who have received one dose of MCV in past 5 years, and both working at a hospital in Beijing, occurred in 18th and 20nd of January, respectively. Out of the 102 contacts, one additional case (case 3) who had a close, long-term co-exposure with case 1 was reported subsequently. No additional cases of measles occurred among 15 contacts of case 3. The index case was not ascertained through the outbreak review. All three cases had laboratory confirmation of measles infection. Both case 1 and case 2 had high-avidity IgG antibody characteristic of a secondary immune response and developed a modified clinical presentation. This report confirms that a vaccinated individual with documented secondary vaccine failure (SVF) could transmit measles and is the second report since a New York City outbreak (the first report in China). The outbreak represented a series of rare events, so we can conclude that the SVF individuals in the transmission chain of measles are unlikely to threaten measles elimination. The importance of the herd immunity in preventing transmission and sensitive surveillance activities in case of misdiagnosis is emphasized

    The incidence of herpes zoster in China: A meta-analysis and evidence quality assessment

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    This review aimed to estimate the disease burden of herpes zoster (HZ) in China and explore the application of the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach in studies of disease burden. We searched for the literature of observational studies analyzing HZ incidence in populations of all ages in China. Meta-analysis models were constructed to calculate the pooled incidence of HZ and pooled risks of postherpetic neuralgia (PHN), HZ recurrence, and hospitalization. Subgroup analysis was performed according to gender, age, and quality assessment score. The quality of evidence for incidence was rated using the GRADE system. Twelve studies with a total of 25,928,408 participants were included in this review. The pooled incidence for all ages was 4.28/1000 person years (95% CI 1.22–7.35). It increased with the increasing in age especially for individuals aged ≥60 y, which was 11.69/1000 person years (95% CI 6.56–16.81). The pooled risks of PHN, recurrence, and hospitalization were 12.6% (95% CI 10.1–15.1), 9.7% (95% CI 3.2–16.2), and 6.0/100,000 population (95% CI 2.3–14.2), respectively. The quality of the evidence assessment of the pooled incidence by the GRADE for all ages was ‘low’; however, it was ‘moderate’ for the ≥60 yold subgroup. HZ is a serious public health problem in China and is more significant in individuals older than 60 y. Therefore, an immunization strategy for the zoster vaccine should be considered. The evidence quality assessment by the GRADE approach indicated that we had more confidence in the estimation of aged population
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