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Objective: To analyse the pan-genome of three black-pigmented periodontal pathogens: Porphyromonas gingivalis, Prevotella intermedia and Prevotella nigrescens. Methods: Pan-genome analyses of 66, 33 and 5 publicly available whole-genome sequences of P. gingivalis, P. intermedia and P. nigrescens, respectively, were performed using Pan-genome Analysis Pipeline software (version 1.2.1; Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, PR China). Phylogenetic trees were constructed based on the entire pangenome and single nucleotide polymorphisms within the core genome. The distribution and abundance of virulence genes in the core and dispensable genomes were also compared in the three species. Results: All three species possess an open pan-genome. The core genome of P. gingivalis, P. inter)media and P. nigrescens included 1001, 1514 and 1745 orthologous groups, respectively, which were mainly related to basic cellular functions such as metabolism. The dispensable genome of P. gingivalis, P. intermedia and P. nigrescens was composed of 2814, 2689 and 906 orthologous groups, respectively, and it was enriched in genes involved in pathogenicity or with unknown functions. Phylogenetic trees presented a clear separation of P. gingivalis, P. intermedia and P. nigrescens, verifying the reclassification of the black-pigmented species. Furthermore, the three species shared almost the same virulence factors involved in adhesion, proteolysis and evasion of host defences. Some of these virulence genes were conserved across species whereas others belonged to the dispensable genome, which might be acquired through horizontal gene transfer. Conclusion: This study highlighted the usefulness of pan-genome analysis to infer evolutionary cues for black-pigmented species, indicating their homology and phylogenomic di [ABSTRACT FROM AUTHOR]

Objective To assess the relationship between fine particulate matter (PM2.5) concentration and ischaemic heart disease (IHD) morbidity and mortality. Methods A time-series study conducted in Beijing from 1 January 2010 to 31 December 2012. Data on 369469 IHD cases and 53247 IHD deaths were collected by the Beijing Monitoring System for Cardiovascular Diseases, which covers all hospital admissions and deaths from IHD from Beijing's population of 19.61 million. Results The mean daily PM2.5 concentration was 96.2 μg/m³ with a range from 3.9 to 493.9 μg/m³. Only 15.3% of the daily PM2.5 concentrations achieved WHO Air Quality Guidelines target (25 μg/m³) in the study period. The dose-response relationships between PM2.5 and IHD morbidity and mortality were non-linear, with a steeper dose-response function at lower concentrations and a shallower response at higher concentrations. A 10 μg/m³ increase in PM2.5 was associated with a 0.27% (95% CI 0.21 to 0.33%, p<2.00×10-16) increase in IHD morbidity and a 0.25% (95% CI 0.10 to 0.40%, p=1.15×10-3) increase in mortality on the same day. During the 3 years, there were 7703 cases and 1475 deaths advanced by PM2.5 pollution over expected rates if daily levels had not exceeded the WHO target. Conclusions PM2.5 concentration was significantly associated with IHD morbidity and mortality in Beijing. Our findings provide a rationale for the urgent need for stringent control of air pollution to reduce PM2.5 concentration. [ABSTRACT FROM AUTHOR]

This study assessed the extent to which social sexism affects Chinese women's perception and evaluation of other women's performance. A sample of 100 college women was selected in a top university in Beijing, China, and was asked to read six scholastic essays and then evaluate the quality of the essays and competence of the authors. Male and female names were randomly assigned as authors of the essays, and the respondents were blind to the arrangement. Results showed that the essays assumed to be written by male authors did not receive higher scores than those assumed to be written by female authors on quality or competence items. Sexism is not marked among these highly educated young women. [ABSTRACT FROM AUTHOR]