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Improving the digital citizenship of secondary vocational students is critical for cultivating vocational talents in education. It is an inevitable requirement for modernizing vocational education. Focusing on social media competence, this study explores possible ways to improve the digital citizenship of secondary vocational students. A total of 469 secondary vocational students in Wuhan city, Hubei province, were investigated using questionnaires. The data analysis shows that the four dimensions of social media competence (technical use, content interpretation, content generation, and anticipatory reflection) significantly predict digital citizenship. On this basis, we propose four paths for improving the digital citizenship of secondary vocational students: creating a suitable environment for secondary vocational students to apply their skills in information technology; enhancing the ability of secondary vocational students to discriminate about information on the Internet; improving students' interpersonal communication ability when dealing with technical support; building an early warning system for secondary vocational students' behavioral perception. [ABSTRACT FROM AUTHOR]

Background: Wuhan was the first epicentre of COVID-19 in the world, accounting for 80% of cases in China during the first wave. We aimed to assess household transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and risk factors associated with infectivity and susceptibility to infection in Wuhan.Methods: This retrospective cohort study included the households of all laboratory-confirmed or clinically confirmed COVID-19 cases and laboratory-confirmed asymptomatic SARS-CoV-2 infections identified by the Wuhan Center for Disease Control and Prevention between Dec 2, 2019, and April 18, 2020. We defined households as groups of family members and close relatives who did not necessarily live at the same address and considered households that shared common contacts as epidemiologically linked. We used a statistical transmission model to estimate household secondary attack rates and to quantify risk factors associated with infectivity and susceptibility to infection, accounting for individual-level exposure history. We assessed how intervention policies affected the household reproductive number, defined as the mean number of household contacts a case can infect.Findings: 27 101 households with 29 578 primary cases and 57 581 household contacts were identified. The secondary attack rate estimated with the transmission model was 15·6% (95% CI 15·2-16·0), assuming a mean incubation period of 5 days and a maximum infectious period of 22 days. Individuals aged 60 years or older were at a higher risk of infection with SARS-CoV-2 than all other age groups. Infants aged 0-1 years were significantly more likely to be infected than children aged 2-5 years (odds ratio [OR] 2·20, 95% CI 1·40-3·44) and children aged 6-12 years (1·53, 1·01-2·34). Given the same exposure time, children and adolescents younger than 20 years of age were more likely to infect others than were adults aged 60 years or older (1·58, 1·28-1·95). Asymptomatic individuals were much less likely to infect others than were symptomatic cases (0·21, 0·14-0·31). Symptomatic cases were more likely to infect others before symptom onset than after (1·42, 1·30-1·55). After mass isolation of cases, quarantine of household contacts, and restriction of movement policies were implemented, household reproductive numbers declined by 52% among primary cases (from 0·25 [95% CI 0·24-0·26] to 0·12 [0·10-0·13]) and by 63% among secondary cases (from 0·17 [0·16-0·18] to 0·063 [0·057-0·070]).Interpretation: Within households, children and adolescents were less susceptible to SARS-CoV-2 infection but were more infectious than older individuals. Presymptomatic cases were more infectious and individuals with asymptomatic infection less infectious than symptomatic cases. These findings have implications for devising interventions for blocking household transmission of SARS-CoV-2, such as timely vaccination of eligible children once resources become available.Funding: National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities, US National Institutes of Health, and US National Science Foundation. [ABSTRACT FROM AUTHOR]

Exposure to air pollution has been linked with altered immune function in adults, but little is known about its effects on early life. This study aimed to investigate the effects of exposure to air pollution during prenatal and postnatal windows on cell-mediated immune function in preschoolers. Pre-school aged children (2.9 ± 0.5 y old, n = 391) were recruited from a mother-child cohort study in Wuhan, China. We used a spatial-temporal land use regression (LUR) model to estimate exposures of particulate matter with aerodynamic diameters ≤2.5 μm (PM 2.5) and ≤10 μm (PM 10), and nitrogen dioxide (NO 2) during the specific trimesters of pregnancy and the first two postnatal years. We measured peripheral blood T lymphocyte subsets and plasma cytokines as indicators of cellular immune function. We used multiple informant models to examine the associations of prenatal and postnatal exposures to air pollution with cell-mediated immune function. Prenatal exposures to PM 2.5 , PM 10 , and NO 2 during early pregnancy were negatively associated with %CD3+ and %CD3+CD8+ cells, and during late pregnancy were positively associated with %CD3+ cells. Postnatal exposures to these air pollutants during 1-y or 2-y childhood were positively associated with IL-4, IL-5, IL-6, and TNF-α. We also observed that the associations of prenatal or postnatal air pollution exposures with cellular immune responses varied by child's sex. Our results suggest that exposure to air pollution during different critical windows of early life may differentially alter cellular immune responses, and these effects appear to be sex-specific. [Display omitted] • Effects of air pollution exposure on cell-mediated immune responses were estimated. • Late pregnancy air pollution exposures were positively related to %CD3+ cells. • Early pregnancy air pollution exposures were related to reduced %CD3+ and %CD3+CD8+ cells. • Postnatal air pollution exposures were positively associated with certain cytokines. • There were sex-specific associations between air pollution exposures and immune responses. [ABSTRACT FROM AUTHOR]

• Associations between cadmium exposure and cellular immune responses were examined. • Prenatal cadmium exposure was associated with reduced T lymphocyte subsets and increased Th2 cytokines. • The effects of prenatal cadmium exposure on cellular immune responses primarily occurred in females. • No clear associations between children's concurrent cadmium exposure and cellular immune responses were observed. Experimental studies have demonstrated that cadmium exposure induces alterations on immune function, but epidemiological evidence is lacking. To examine the associations between prenatal and postnatal cadmium exposure and cellular immune responses among pre-school children. Pre-school aged children (n = 407) were followed from a prospective birth cohort study in Wuhan, China. Maternal urinary and children's plasma cadmium concentrations were measured as biomarkers of prenatal and postnatal cadmium exposure, respectively. Children's cellular immune responses were assessed by peripheral blood T lymphocyte subsets and plasma cytokines. Multivariable adjusted models were applied to estimate the associations of prenatal and postnatal cadmium exposure with T lymphocyte subsets and cytokines, and the effect modification by child gender were also examined. Maternal urinary cadmium was associated with reduced absolute counts of CD3+CD4+ cells (−12.45%; 95% CI: −23.74%, 0.40% for the highest vs. lowest quartile; p for trend = 0.045). Inverse associations of maternal urinary cadmium with %CD3+CD4+ cells and CD4+/CD8+ ratio were only observed among females (both p-interaction < 0.050); whereas an inverse association with absolute counts of CD3+CD8+ cells was only observed among males (p-interaction = 0.057). Positive associations of maternal urinary cadmium with %CD3+CD4+ cells, interleukin-4 (IL-4), and IL-6 were only observed among females, although there were no significant interactions. We observed no clear associations of children's plasma cadmium with T lymphocyte subsets and cytokines. Prenatal but not postnatal cadmium exposure was associated with sex-specific alterations on children's cellular immune responses. [ABSTRACT FROM AUTHOR]