Résumé
OBJECTIVE: To establish a methodology for the detection of cyclohexanone in workplace air by capillary column gas chromatography.METHODS: The air sample in the workplace was collected with activated carbon tube and desorbed with carbon disulfide.The extracts were separated by FFAP capillary column and detected with flame ionization detector,and quantified using standard curve.RESULTS: The linearity range of cyclohexanone was 10.00-1 000.00 mg/L,and the correlation coefficient was 0.999 9.The detection limit and the lower limit of quantification were 1.31 and 4.37 mg/L,respectively.The minimum detectable concentration and the minimum quantitative mass concentration were 4.37 and13.11 mg/m~3,respectively.The average desorption efficiency of cyclohexanone was 95.80%-97.88%.The within-run and between-run relative standard deviation were 0.52%-3.12% and 3.28%-4.75% respectively.The samples could be stored at room temperature for 7 days.CONCLUSION: This method is simple and accurate.It is suitable for the determination of a large number of samples.
Résumé
Objective To investigate the effect of dexmedetomidine on liver function,plasma cytokine levels,and oxidative stress due to ischemia/reperfusion injury in patients undergoing hepatolobectomy.Methods A total of 106 patients who underwent hepatolobectomy in General Hospital of Jizhong Energy Fengfeng Group Co.,Ltd.from January 2014 to January 2016 were enrolled and randomly divided into control group and observation group,with 53 patients in each group.The patients in the observation group were given 1 μg/kg/h dexmedetomidine within 10 minutes,followed by continuous intravenous infusion of 0.5 μg/kg/h dexmedetomidine,and those in the control group were given an equal volume of 0.9％ sodium chloride.The two groups were compared in terms of liver function parameters,plasma cytokine levels,and oxidative stress due to ischemia/reperfusion injury after anesthesia (T1),before abdominal closure (T2),and at 1,4,and 8 hours after surgery (T3,T4,and T5,respectively).The chi-square test was used for comparison of categorical data between groups;the t-test was used for comparison of indices between groups,the sphericity test was used for comparison of indices at different time points,and an analysis of variance was performed for repeated measurement data with P ＜ 0.05.Results The two groups had significantly higher alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels at T2,T3,T4,and T5 than at T1 (ALT:F =43.72 and 44.16,both P ＜ 0.001;AST:F =53.87 and 65.44,both P ＜ 0.001),and the observation group had significantly lower levels than the control group atT2,T3,T4,andT5 (ALT:t =20.54,22.01,36.68,and 38.15,all P＜0.001;AST:t =32.27,41.08,52.82,and71.89,all P ＜ 0.001).The two groups had significantly higher levels of tumor necrosis factor α (TNFα) and interleukin-8 (IL-8) at T3,T4,and T5 than at T1 (TNFα:F =54.37 and 24.75,both P ＜ 0.001;IL-8:F =47.24 and 27.39,both P ＜ 0.001),and the observationgroup had significantly lower levels than the control group at T3,T4,and T5 (TNFα:t =59.39,86.32,and 83.16,all P ＜ 0.001;IL-8:t =74.47,72.29,and 76.67,all P ＜ 0.001).The two groups had a significantly higher level of malondialdehyde at T3,T4,and T5 than at T1 (F =37.65 and 17.44,both P ＜0.001),and the observation group had a significantly lower level than the control group at T3,T4,and T5 (t =17.35,19.11,and 24.12,all P ＜ 0.001).The two groups had a significantly lower level of superoxide dismutase at T3,T4,and T5 than at T1 (F =36.54 and 33.65,both P ＜0.001),and the observation group had a significantly higher level than the control group at T3,T4,and T5 (t =68.64,66.35,and 59.48,all P ＜0.001).Conclusion Dexmedetomidine can effectively inhibit liver injury,reduce the levels of cytokines,and alleviate ischemia/reperfusion injury in patients undergoing hepatectomy.