Objective To study the effect of lipid peroxidation and anti-lipid peroxidation and the pigment in skin of C57BL/6 mice exposed to arsenic.Methods Forty male C57BL/6 mice were divided into four groups via the random number table method,ten mice in each group,and the mice were fed ad libitum drinking water containing arsenic at 0,1,5 and 25 mg/L concentrations for a period of 6 weeks,respectively.Twelve days before the end of the experiment,procedure of depilation was performed to induce anagen of hair cycle.On the 30th day of experiment,the activity of superoxide dismutase (SOD) was determined by nitrite method,the activity of glutathione peroxidase (GSH-Px) was determined by dithiobisobenzoic acid method,the content of malondialdehyde (MDA) in skin of C57BL/6 mice was determined by thiobarbituric acid method.Melanin was measured by NaOH dissolution method.Results No significant difference was found in body weight and water intaken between groups (F =0.119,0.363,P ＞ 0.05).The activity of SOD [(16.00 ± 5.05),(13.96 ± 2.02),(10.46 ± 3.14) U/mg prot] in 1,5 and 25 mg/L arsenic groups were all significantly lower than that in control group [(20.36 ± 4.82) U/mg prot,P ＜ 0.05].GSH-Px activity in 1,5 and 25 mg/L arsenic groups [(98.14 ± 23.92),(87.18 ± 10.87),(53.56 ± 19.97) U/mg prot] were all significantly lower than that in control group [(119.34 ± 33.14) U/mg prot,P ＜ 0.05].While MDA levels in 5 and 25 mg/L arsenic groups [(9.09 ± 2.04),(11.48 ± 2.21) nmol/mg prot] were significantly higher than that of control group [(6.19 ± 0.56) nmol/mg prot,P ＜ 0.05] and that of 1 mg/L arsenic group [(6.52 ± 1.67) nmol/mg prot,P ＜ 0.05).No significant difference was found in melanin levels (P ＞ 0.05).Conclusions Lipid peroxidation and the decreasing of antioxidation may be one of the mechanisms of arsenic-induced skin damage.Arsenic-induced skin melanin content change is not found.

Objective:To study the life characteristics and related risk factors of patients with depression in Shandong Province.Methods:Based on the 2015 mental epidemiological survey database in Shandong Province,a total of 832 patients with depression,807 high-risk individuals with depression,and 819 low-risk individuals were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition(DSM-Ⅳ)and the Structured Clinical Interview for DSM-Ⅳ-TR Axis I Disorders,Research Version(SCID-I/P).In 2020,SCID-I/P was used for re diagnosis,and the General Health Questionnaire(GHQ-12),Simple Quality of Life question-naire,Pittsburgh sleep quality index(PSQI),Childhood Trauma Questionnaire(CTQ),Social Support Rating Scale(SSRS),Global Pain Scale(GPS),Montreal Cognitive Assessment(MoCA),Simplified Coping Style Question-naire(SCSQ)were used for evaluation.Compare changes in the quality of life of depression patients and construct a risk factor model.Results:Patients with depression had lower scores on the simple quality of life questionnaire at baseline and at retest after 5 years than those in the high-and low-risk groups,those in remission of depression had higher scores on the simple quality of life questionnaire at baseline and at retest after 5 years than those in non-re-mission,and those with new-onset disorder in the high-and low-risk groups had lower scores on the simple quality of life questionnaire at baseline and at retest after 5 years than those with no-onset disorder(Ps＜0.001).Depres-sion diagnosis and PSQI scale scores at baseline negatively predicted at retest after 5 years(β=-0.06,-0.15),while coping style tendencies at baseline positively predicted(β=0.06).The simple quality of life questionnaire at baseline negatively predicted depression diagnosis at retest after 5 years,GHQ-12 scores at retest after 5 years,and PSQI scale scores at retest after 5 years(β=-0.11,-0.17,-0.09),while the simple quality of life question-naire at baseline positively predicted coping style tendencies at retest after 5 years(β=0.13).Depression diagnosis at retest after 5 years,GHQ-12 scores at retest after 5 years,PSQI scale scores at retest after 5 years,coping style tendencies at retest after 5 years,SSRS scale scores,CTQ scale scores,GPS scale scores,and the simple quality of life questionnaire at baseline all influenced the simple quality of life questionnaire at retest after 5 years through ei-ther direct or indirect pathways.Conclusion:It suggest that the quality of life is lower in patients with depression than in the general population.Depression diagnosis,sleep,mental health,pain,social support,childhood trauma and coping are direct and indirect risk factors affecting life.