Objective: To study Duraphat fluoride varnish on the remineralization of demineralized permanent enamel by carbonated beverages. Methods: 30 permanent premolar teeth from 12 to 25 years old young people were collected from orthodontic extraction. Enamel blocks were prepared from each tooth and randomly divided into group A (Coco cola), B(deionized water), C(Coco cola + Duraphat), D(Coco cola + 2％ NaF) and E(Coco cola + artificial saliva) (n = 15), the specinens were respectively treated for 7 d. The enamel surface were observed by scanning electron microscope(SEM). The Ca2 + and P3 + content(weight percentage) were detected by energy spectrum analyzer. Results: The surface of permanent enamel of group A showed a characteristic honeycomb-like appearance, that of group B were smooth. Group C showed irregular large globule deposits on the surface, group D showed some globule structures on the surface, group E showed a little deposits on the surface. Ca2 + and P3 + content of group A was lower than that of group B, in group C was higher than in group E(P＜ 0. 05). Ca2 + content in group D was higher than that in group E(P＜ 0. 05). Conclusion: Duraphat fluoride varnish can promote the remineralization of demineralized permanent enamel by carbonated beverage.

Objective : To investigate the mechanism of sertoli/spermatogenic injury induced by cigarette smoke extract(CSE) based on ROS/NLRP3 signaling pathway. Methods : The sertoli/spermatogenic of rat were cultured in vitro , and they were divided into control group , cigarette Smoke extract (CSE) group and CSE + NLRP3 inflammosome inhibitor MCC950 group. Cell viability was detected by CCK⁃8 assay; Lactate dehydrogenase ( LDH) was used to detect cell membrane damage ; reactive oxygen species ( ROS) production was used to detect oxidative stress level ; Hoechst/PI fluorescent staining was used to detect cell pyroptosis. Real⁃time quantitative PCR ( RT⁃qPCR) was used to determine the mRNA level of NLRP3 , ASC , Caspase⁃1 , GSDMD , IL⁃1β and IL⁃18. Western blot was used to determine the protein level of NLRP3 , ASC , Caspase⁃1 , GSDMD , IL⁃1β and IL⁃18. Results: CCK⁃8 assay showed that cell viability decreased in CSE group (P < 0. 001) , LDH leakage rate (P < 0. 001) and ROS (P < 0. 001) production increased. Compared to the CSE group , cell viability increased (P < 0. 001) , LDH leakage rate (P < 0. 01) and ROS (P < 0. 001) production decreased in CSE + MCC950 group. The number of PI staining cells in CSE group was more than that in control group and CSE + MCC950 group , but staining cells in CSE + MCC950 group was less than that in CSE group. RT⁃qPCR and Western blot results showed that the expression levels of NLRP3 , ASC , Caspase⁃1 , GSDMD , IL⁃1β and IL⁃18 increased in CSE group but decreased in CSE+ MCC950 group. Conclusion The oxidative stress and inflammation of sertoli/spermatogenic induced by ciga⁃ rette smoke may be related to the activation of ROS/NLRP3 signaling pathway.

Background Occupational stress has become one of the main factors affecting people's physical and mental health, and there are many sources of occupational stress in petrochemical enterprises. Objective To evaluate the current situation of occupational stress and its related factors among employees in a petrochemical enterprise, and to provide a scientific basis for reduing the risk of occupational stress among employees in petrochemical enterprises. Methods In June 2022, a cross-sectional questionnaire survey was conducted in a petrochemical enterprise in Hainan, including a general information questionnaire for basic information, the Effort-Reward Imbalance (ERI) for occupational stress, and the Pittsburgh Sleep Quality Index (PSQI) for sleep quality. Chi-square test was used to compare differences in positive occupational stress by demographic characteristics, occupational characteristics, behavior, and occupational disease hazards. Logistic regression was employed to evaluate factors associated with occupational stress. Results Of the 1129 questionnaire distributed, a total of 999 valid questionnaire were returned,with a valid recovery rate of 88.5%. The positive rate of occupational stress among employees in the petrochemical enterprise was 29.5%. There were statistically significant differences in the positive rate of occupational stress among the employees grouped by gender, age, marital status, body mass index (BMI), monthly income, length of service, smoking, weekly working hours, type of work, working mode, sleep quality, noise exposure, and high temperature exposure (P<0.05). In terms of positive occupational stress among subcategories: workers being male (vs. female), working ＞40 h per week (vs. ≤40 h per week), regular day shift (vs. shift work), smoking (vs. not smoking), with exposure to noise and heat (vs. without such exposure), and having poor sleep quality (vs. good sleep quality) reported higher positive occupational stress rates (P＜0.05). The results of pairwise comparison showed that the positive rate of occupational stress in divorced (50.0%) or married (32.0%) workers was higher than that in single (27.1%) workers, and higher in operation workers (30.6%) than in other types of work (20.5%) (P＜0.05). The trend chi-square results showed that the positive rate of occupational stress increased linearly with the increase of age, length of service, BMI, or monthly income (P＜0.05). The results of logistic regression analysis after adjustment showed that workers who worked ＞40 h a week had a higher risk of occupational stress than those who worked ≤40 h a week, and the OR (95%CI) was 1.909 (1.135, 3.211); the workers of other types of work had a lower risk of reporting occupational stress than operation workers, and the OR (95%CI) was 0.513 (0.272, 0.968); the workers with noise exposure had a higher risk of occupational stress than the workers without, and the OR (95%CI) was 2.457 (1.070, 5.642). Conclusion The positive rate of occupational stress among employees in this petrochemical enterprise is high. Among them, operators, working hours per week＞40 h, and noise exposure may increase the incidence of occupational stress. The enterprise should actively take measures to reduce the occurrence of occupational stress among employees.