Objective To establish a rapid,sensitive and specific assay based on real-time PCR combined with reverse transcription for detecting and identifying viable Listeria monocytogenes.Methods The hlyA gene of Listeria monocytogenes was chosen as target,and then the primers and TaqMan probe were designed.Both ends of probe were modified with two different fluorescence groups.The PCR reaction was optimized systematically.The mRNA of Listeria monocytogenes was extracted,and then reverse transcription was performed through random primer.The cDNA Was detected by real-time PCR.Then the specificity,sensitivity and reproducibility of real-time PCR were estimated.In final,real-time PCR was applied to detect 20 mocked double-blind samplea.Results Viable Listeria monocytogenes were detected by real-time PCR accurately and quickly,and meanwhile,none of other bacteria and non-viable Listeria monocytogenes could be identified.The sensitivity was 10 CFU/ml in pure culture and 103CFU/ml for mocked samples respectively.The coefficient of variation of intra-assay and inter-assay Was less than 5%.When this assay was applied directly to identify 20 mocked double-blind samples,10 of these were positive to viable Listeria monocytogenes,5 were negative to non-viable Listeria monocytogenes,and 5 were negative to other pathogens.Conclusion It is demonstrated that real-time PCR is a reliable,accurate and feasible assay for viable Listeria monocytogenes.The establishment of this assay provided complete data for analysis and diagnosis in the field of food safety and epidemiologic survey.

Objective: To investigate the clustering of health-risk behaviors and its influencing factors among children and adolescents in Yancheng City, Jiangsu Province, so as to provide insights into the prevention and control of health-risk behaviors among children and adolescents. Methods: Students were randomly sampled from 4 primary schools, 4 junior high schools and 4 senior high schools in Yancheng City using a multi-stage stratified cluster random sampling method from September to December 2021. Students' demographics and 12 health-risk factors including unhealthy diet, insufficient physical activity and attempted smoking were collected using the Student's Health Status and Influencing Factors Questionnaire by Jiangsu Provincial Center for Disease Control and Prevention, and factors affecting the clustering of health-risk behaviors were identified using a multivariable linear regression model. Results: A total of 2 925 valid questionnaires were recovered, and the respondents included 1 611 boys (55.08%) and 1 314 girls (44.92%). A total of 2 896 respondents were detected with health-risk behaviors, with a detection rate of 99.09%, and 2 772 respondents were detected with clustering of health-risk behaviors (93.06%). Insufficient sleep, insufficient physical activity and insufficient duration of outdoor activity were predominant patterns of clustering. The median number of health-risk behaviors was 4.00 (interquartile range, 2.00) per capita. Multivariable linear regression analysis showed that boys (β=0.232), grade (junior high school, β=0.519; senior high school, β=0.427), urban area (β=0.241), living at school (β=0.395), family structure (single parental family, β=0.188; other families, β=0.344) and father's education level of primary school and below (β=0.369) were factors affecting clustering of health-risk behavior among primary and high school students. Conclusions The detection of health-risk behaviors is high among children and adolescents in Yancheng City, and insufficient sleep, insufficient physical activity and insufficient duration of outdoor activity are predominant health-risk behaviors. Boys, junior high school and above, urban areas, living at schools, single parents, and fathers with a low educational level lead to a high degree of clustering of health-risk behaviors.

Objective To compare the antibody persistence 5 years after primary immunization with 5 μg and 10 μg recombinant hepatitis B vaccine (HepB) among newborns with normal and high response.Methods Newborns who completed three doses of 5 μ g HepB made by recombinant dexyribonucleic acid technique in Saccharomyces (HepB-SC) or 10 μg HepB made by recombinant dexyribonucleic acid technique in Hansenula polymorpha (HepB-HP) were recruited.Standardized questionnaire was used and blood samples were collected 1-6 months (T0) and five years (T1) after the third dose respectively.The titer of anti-HBs was detected by chemiluminescence microparticle imunoassay (CMIA).Those who achieved normal or high antibody response (anti-HBs titer ≥100 mIU/ml) were included in the study and the positive rate (≥ 10 mIU/ml) and titer of anti-HBs at T1 were compared between 5 μg HepB group and 10 μg HepB group.Multivariable analysis was conducted to identify the independent factors associated with the antibody persistence.Results The positive rate of anti-HBs at T1 was 49.92％ (943/1 883) and 75.92％ (1 135/1 495) respectively in 5 μg HepB group and 10 μg HepB group,the difference was significant (x2=237.75,P＜0.001).The anti-IBs geometric mean concentrations at T1 were 10.23 mIU/ml (95％CI:9.38-11.16) and 28.91 mIU/ml (95％CI:26.65-31.35) in the two groups respectively,the difference was also significant (F=280.36,P＜0.001).Among those whose anti-HBs titer was ＜ 10 mIU/ml at T1,the distributions of anti-HBs titer were significantly different between 5 μg HepB group and 10 μg HepB group (x2=39.75,P＜ 0.001).The multivariable analysis showed that dosage of HepB was independently associated with both positive rate and titer of anti-HBs at T1 after excluding the other factors [P＜0.001,OR=1.44(95％ CI:1.20-1.73);P＜0.001,β =0.27 (95％ CI:0.14-0.40)].Conclusion Five year anti-HBs persistence after primary immunization with 10 μg HepB might be better than that after primary immunization with 5 μg HepB among infants who achieved normal or high anti-HBs response after primary HepB immunization.

Rutin-degrading enzymes (RDE) can degrade rutin into poorly water soluble compound, quercetin, and cause the bitter taste in tartary buckwheat. In the present study RDE from Yu 6-21 tartary buckwheat seeds was purified by ammonium sulphate precipitation, followed by hydrophobic interaction chromatography on Phenyl Sepharose CL-4B, ion exchange chromatography on CM-Cellulose and gel filtration chromatography on Sephadex G-150. Purified RDE showed single band with molecular weight of 66 kDa on SDS-PAGE. The optimum pH and temperature of RDE were 5.0 and 50 ℃ respectively. The Km was 0.27 mmol/L, and the Vmax was 39.68 U/mg. The RDE activity could be inhibited by Cu²⁺, Zn²⁺, Mn²⁺ and EDTA, and showed tolerance to 50% methanol (V/V). The N terminal sequence (TVSRSSFPDGFLFGL) was obtained by Edman degradation method and 15 internal peptide sequences were determined by MALDI-TOF-MS (matrix-assisted laser desorption ionization time of flight mass spectrometry). These results established the foundations for identification of the candidate gene of RDE via transcriptome data and further studying RDE biological function.

Radiotherapy uses high-energy X-rays or other particles to destroy cancer cells and medical practitioners have used this approach extensively for cancer treatment (Hachadorian et al., 2020). However, it is accompanied by risks because it seriously harms normal cells while killing cancer cells. The side effects can lower cancer patients' quality of life and are very unpredictable due to individual differences (Bentzen, 2006). Therefore, it is essential to assess a patient's body damage after radiotherapy to formulate an individualized recovery treatment plan. Exhaled volatile organic compounds (VOCs) can be changed by radiotherapy and thus used for medical diagnosis (Vaks et al., 2012). During treatment, high-energy X-rays can induce apoptosis; meanwhile, cell membranes are damaged due to lipid peroxidation, converting unsaturated fatty acids into volatile metabolites (Losada-Barreiro and Bravo-Díaz, 2017). At the same time, radiotherapy oxidizes water, resulting in reactive oxygen species (ROS) that can increase the epithelial permeability of pulmonary alveoli, enabling the respiratory system to exhale volatile metabolites (Davidovich et al., 2013; Popa et al., 2020). These exhaled VOCs can be used to monitor body damage caused by radiotherapy.
Breath Tests/methods* ; Exhalation ; Humans ; Quality of Life ; Respiratory System/chemistry* ; Volatile Organic Compounds/analysis*