Objective To investigate the microbial contamination and its influencing factors of indoor air in public places in Xi'an City, to assess the health risk of employees, and to provide a scientific basis for improving the indoor environment of public places. Methods Total bacterial count and total fungal count in indoor air were monitored in hotels/inns, shopping malls/supermarkets, gyms, and waiting rooms in Xi'an from 2023 to 2024. The health risk assessment of employees was evaluated according to the Chinese Population Exposure Parameters Manual (Adult Volume). Results Overall, the standard-exceeding rate of total bacterial count in Xi'an was 3.85%, and the median values of total bacterial count and total fungal count were 350 CFU/m3 and 300 CFU/m3, respectively. The results of the generalized linear model showed that high indoor temperature and PM10 levels were associated with increased indoor bacterial concentrations (β>0, P<0.05), while high daily passenger flow, and high indoor relative humidity and PM₁₀ levels were associated with increased indoor fungal concentrations (β>0, P<0.05). The multivariate logistic regression showed that high levels of indoor bacterial and fungal concentrations were risk factors for respiratory discomfort among employees. The hazard quotient (HQ) values for all types of public places were less than 1, indicating that the health risk of microbial aerosol exposures for employees was relatively low. Conclusion The indoor microbial pollution in public places in Xi'an is relatively mild, but countermeasures still need to be taken to reduce indoor air microbial contamination.

ObjectiveTo investigate the spontaneous premature cardiac aging in SHJH^hr mice. MethodsA comparative study was conducted between SHJH^hr mice (SHJH^hr group) and wild-type ICR mice (WT group) at different ages (10 and 24 weeks). Cardiac function was analyzed using a small animal in vivo ultrasound imaging system. After euthanasia, organs were collected and weighed to assess the extent of cardiac atrophy. Cardiac pathological damage was observed using hematoxylin-eosin (HE) staining. Cardiac fibrosis was analyzed using Masson staining. Myocardial cell area was analyzed after wheat germ agglutinin (WGA) staining. The activities of oxidative damage indicators in myocardial tissue, including superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT), as well as the content of 8-hydroxy-2'-deoxyguanosine (8-OHdG), were measured using enzyme-linked immunosorbent assay. Real-time fluorescence quantitative PCR was used to measure the mRNA expression levels of factors associated with inflammation, fibrosis, and oxidative stress. Colorimetric assay was used to measure malondialdehyde (MDA) levels. ResultsCompared to WT group mice of the same age, 10-week-old mice in the SHJH^hr group showed no significant differences in stroke volume (SV), ejection fraction (EF), fractional shortening (FS), or heart and lung weights. However, at 24 weeks of age, mice in the SHJH^hr group had significantly lower SV, EF, and FS values compared to mice of the same age in the WT group (P<0.05), with no significant change in lung weight but a significant reduction in heart weight (P<0.05). Histological analysis of heart tissue from 24-week-old mice revealed no significant difference in cardiac fibrosis levels between SHJH^hr and WT groups, but WGA staining showed a significant reduction in myocardial cell area in mice in the SHJH^hr group (P<0.05). PCR analysis revealed a significant downregulation of mRNA levels of oxidative stress factors Sod2, Gpx1, and Cat genes (P<0.05). Biochemical assays indicated significantly reduced activities of oxidative damage-related enzymes SOD, GPX, and CAT in myocardial tissue (P<0.05), while the levels of oxidative damage markers 8-OHdG and MDA significantly increased (P<0.05). ConclusionMice in the SHJH^hr group exhibit premature cardiac aging, which may be associated with oxidative stress damage in myocardial tissue.

Purpose: Zinc finger protein 639 (ZNF639) is often found within the overlapping amplicon of PIK3CA, and previous studies suggest its involvement in the pathogenesis of esophageal and oral squamous cell carcinomas. However, its expression and significance in breast cancer remain uncharacterized. Methods: Immunohistochemical analysis of ZNF639 was performed using tissue microarrays.Functional studies, including colony formation, Transwell cell migration, and in vivo metastasis, were conducted on breast tumor cells with ZNF639 knockdown via small interfering RNA transfection. Results: Reduced ZNF639 immunoreactivity was observed in 82% of the breast cancer samples, independent of hormone receptor and human epidermal growth factor receptor 2 status. In multivariate Cox regression analyses, ZNF639 expression was associated with favorable survival outcomes, including recurrence-free survival (hazard ratio, 0.35; 95% confidence interval [CI], 0.14–0.89) and overall survival (hazard ratio, 0.41; 95% CI, 0.16– 1.05). ZNF639 knockdown increased clonogenicity, cell motility, and lung metastasis in NOD/ SCID mice. Following the ZNF639 knockdown, the expression of Snail1, vimentin, and C-C chemokine ligand 20 (CCL20) was upregulated, and the changes in cell phenotype mediated by ZNF639 were reversed by the subsequent knockdown of CCL20. Conclusion Low ZNF639 expression is a novel prognostic factor for recurrence-free survival in patients with breast cancer.

Purpose: Zinc finger protein 639 (ZNF639) is often found within the overlapping amplicon of PIK3CA, and previous studies suggest its involvement in the pathogenesis of esophageal and oral squamous cell carcinomas. However, its expression and significance in breast cancer remain uncharacterized. Methods: Immunohistochemical analysis of ZNF639 was performed using tissue microarrays.Functional studies, including colony formation, Transwell cell migration, and in vivo metastasis, were conducted on breast tumor cells with ZNF639 knockdown via small interfering RNA transfection. Results: Reduced ZNF639 immunoreactivity was observed in 82% of the breast cancer samples, independent of hormone receptor and human epidermal growth factor receptor 2 status. In multivariate Cox regression analyses, ZNF639 expression was associated with favorable survival outcomes, including recurrence-free survival (hazard ratio, 0.35; 95% confidence interval [CI], 0.14–0.89) and overall survival (hazard ratio, 0.41; 95% CI, 0.16– 1.05). ZNF639 knockdown increased clonogenicity, cell motility, and lung metastasis in NOD/ SCID mice. Following the ZNF639 knockdown, the expression of Snail1, vimentin, and C-C chemokine ligand 20 (CCL20) was upregulated, and the changes in cell phenotype mediated by ZNF639 were reversed by the subsequent knockdown of CCL20. Conclusion Low ZNF639 expression is a novel prognostic factor for recurrence-free survival in patients with breast cancer.