OBJECTIVE： A RP－ HPLC method was established for determination of serum concentration of propofol in man METHODS： The mobile phase consisted of methanol－ water（ 68∶ 32v/v） The detection was carried out at wave length 258nm and flow rate 1ml/min with carbamazepine as internal standard RESULTS： The retention times of propofol and carbamazepine were 9 20 and 5 16 min， respectively The mean recovery of propofol was 99％  The within－ day and inter－ day variations were all less than 10％  Propofol and carbamazepine were seperated well The assay linearity was obtained in the range of 1～ 16μ g/ml in serum（ r=0 9 994）  CONCLUSION： The method is sensitive， simple and reliable for the determination of propofol concentration

OBJECTIVE:A RP-HPLC method was established for determination of serum concentration of propofol in man METHODS:The mobile phase consisted of methanol-water(68∶32v/v)The detection was carried out at wave length 258nm and flow rate 1ml/min with carbamazepine as internal standard RESULTS:The retention times of propofol and carbamazepine were 9 20 and 5 16 min,respectively The mean recovery of propofol was 99% The within-day and inter-day variations were all less than 10% Propofol and carbamazepine were seperated well The assay linearity was obtained in the range of 1～16?g/ml in serum(r=0 9 994) CONCLUSION:The method is sensitive,simple and reliable for the determination of propofol concentration

Objective: To investigate the influencing factors of home environment on eczema in preschool children, so as to provide theoretical basis for taking effective regional prevention for preschool children. Methods: From December 2020 to January 2021, a cross sectional survey of 3 049 preschool children was randomly carried out by stratified cluster sampling in Haikou kindergartens, and the impact of indoor environmental factors on preschool children s eczema was analyzed. Chi squared test and binary Logistic regressive were used to analyze the related factors. Results: The prevalence of eczema in preschool children was 13.6%. Multivariate Logistic regression showed that the positive correlation factors of eczema included the new decoration in the mother s residence one year before pregnancy ( OR=1.71, 95%CI =1.09-2.68), the addition of new furniture in the child s residence when the child was 0-1 years old ( OR=1.53, 95%CI =1.03-2.27), cockroaches in the house ( OR=1.35, 95%CI =1.02-1.81) and cleaning of less than once per week ( OR=1.30, 95%CI =1.01-1.66). The starting age of children s collective life since 3 years old ( OR=0.76, 95%CI =0.60-0.96) had a negative correlation with eczema ( P <0.05). Conclusion There are multiple indoor environmental factors related to eczema among preschool children in Haikou city. Parents should take measures to prevent eczema in preschool children by paying attention to home environment and the starting age of children s collective life.

Objective: To investigate the clinical value of coefficient of variation ( RDW-CV) and standard deviation (RDW-SD) of erythrocyte distribution width in the diagnosis of colorectal cancer ( CRC) metastasis． Methods : 91 CRC inpatients were selected as the research subjects．According to whether the tumor was metastatic，they were divided into two groups : 61 cases in the non-metastatic group and 30 cases in the metastasis group．The laboratory indicators of the two groups of patients included : neutrophils count，lymphocyte count，platelet count，carcinoembryonic antigen，plasma prothrombin time，activated partial thromboplastin time，fibrinogen，thrombin time， RDW-CV and RDW-SD and other indicators．The t test was used to compare the means of the two groups，and the pearson correlation was used to analyze the relationship between RDW-CV and RDW-SD with neutrophil count， lymphocyte count，neutrophil count-lymphocyte count ratio (NLR) and carcinoembryonic antigen．Correlation coefficient，receiver operating characteristic curve ( ROC) to assess the area under the curve ( AUC) of RDW-CV， RDW-SD，carcinoembryonic antigen and their combined diagnosis in assessing CRC metastasis. Results: Compared with non-metastatic patients，the RDW-CV and RDW-SD values of metastatic patients were higher (both P < 0. 05) ．Both RDW-CV and RDW-SD levels were positively correlated with carcinoembryonic antigen content．Compared with the AUC of carcinoembryonic antigen in diagnosis of CRC metastasis，the AUC of RDW-CV or RDW-SD combined with carcinoembryonic antigen was higher． Conclusion RDW-CV and RDW-SD have potential clinical application value in differential diagnosis of CRC metastasis.

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.