Acrylamide induces NLRP3 inflammasome activation via oxidative stress- and endoplasmic reticulum stress-mediated MAPK pathway in HepG2 cells.

Acrylamide (AA) is one of the important products of the Maillard reaction. AA hepatotoxicity is related to inflammation, which can be indicated by the activation of NLRP3 inflammasome. In this study, AA activated NLRP3 inflammasome and released a large number of inflammatory factors in HepG2 cells. AA induced oxidative stress (OS) and endoplasmic reticulum stress (ERS) responses in HepG2 cells, accompanied by the activation of the MAPK signaling pathway. When HepG2 cells were pretreated with ROS (NAC) and ERS (4-PBA) inhibitors separately, the activation of NLRP3 inflammasome was inhibited. The MAPK signaling pathway was inhibited when OS and ERS were blocked. HepG2 cells pretreated with MAPK selective inhibitors led to the inhibition on the activation of NLRP3 inflammasome. Overall, we consider that AA induces the activation of NLRP3 inflammasome through the OS- and ERS-mediated MAPK signaling pathway in HepG2 cells.

Mediating role of psychological capital between occupational stress and depressive symptoms in disease prevention and control personnel / 环境与职业医学

Background Occupational stress and depressive symptoms of disease prevention and control personnel are serious. Objective To investigate the relationship between occupational stress, psychological capital, and depressive symptoms of disease prevention and control personnel, and analyze the potential mediating effect of psychological capital on the relationship between occupational stress and depressive symptoms. Methods From July to September 2020, a cluster random sampling method was used to select 2201 employees from 21 centers for disease control and prevention as study subjects covering all levels of administrative divisions in Jiangsu Province. A total of 2036 valid questionnaires were collected with a recovery rate of 92.5%. The Core Occupational Stress Scale, Patient Health Questionnaire, and Psychological Capital Questionnaire were used to investigate their occupational stress, depressive symptoms, and psychological capital. Stratified regression analysis was used to explore the effects of occupational stress and psychological capital on depressive symptoms. A mediating effect model was used to analyze and verify the potential mediating effect of psychological capital on the relationship between occupational stress and depressive symptoms. Results The total scores in M (P25, P75) of occupational stress, depressive symptoms, and psychological capital in the target population were 42.0 (37.0, 48.0), 8.0 (4.0, 9.0), and 4.6 (4.0, 5.0) respectively. The positive rate of occupational stress was 31.0% (631/2036), and the positive rate of depressive symptoms was 22.0% (448/2036). The dimensional scores of organization and reward, and demand and effort of occupational stress were positively correlated with the total score of depressive symptoms [Spearman correlation coefficients (rs) were 0.371 and 0.269, P<0.05]. The dimensional scores of social support and autonomy of occupational stress and the score of psychological capital were negatively correlated with the total score of depressive symptoms (rs=−0.373, −0.112, −0.494, P<0.05). The organization and reward, and demand and effort had positive effects on depressive symptoms (b=0.188, 0.177, P<0.05), while social support and autonomy had negative effects on depressive symptoms (b=−0.290, −0.078, P<0.05), and associated with a 22.5% increase of explanatory variance. Psychological capital had a negative effect on depressive symptoms (b=−0.368, P<0.05), and associated with an 11.0% increase of explanatory variance. Psychological capital had mediating effects on the associations of social support, organization and reward, and autonomy with depressive symptoms, and the mediating effect values were −0.210 (95%CI: −0.253-−0.171), 0.096 (95%CI: 0.071-0.122), and −0.164 (95%CI: −0.229-−0.103), respectively. The corresponding mediating effect percentages were 40.23%, 26.97%, and 45.56%, respectively. Conclusion Occupational stress of disease prevention and control personnel can directly affect depressive symptoms, but also indirectly through psychological capital. Psychological capital plays a partial mediating role in the associations of social support, organization and reward, and autonomy of occupational stress with depressive symptoms. The occurrence of depressive symptoms can be reduced by decreasing occupational stress and increasing psychological capital.

Reflective performance of Ir film in vacuum ultraviolet wavelength region.

This paper theoretically and experimentally investigates the reflective performance of Ir films in the vacuum ultraviolet wavelength region. Ir reflecting layers of different thicknesses on various substrates are calculated and fabricated by the ion-beam-sputtering technique. Their reflectance in the 115 nm to 140 nm wavelength region was measured continuously by a reflectometer located at the National Synchrotron Radiation Laboratory. The testing results show that the reflectance of Si substrates is quite sensitive to the deposited Ir layer thickness, while the reflectance on a quartz or a BK7 glass substrates is higher. The energy of the sputtering ion beam exerts a significant influence on the reflectance of the layer, and the postannealing can cause a substantial decrease in the reflectance. For normal incidence, the reflectance of an Ir film on BK7 glass can reach as high as 30%.

Influence of binding layer on the reflective performance of a Au film in vacuum ultraviolet wavelength region.

We investigate the influence of the binding layer on the reflectance of a Au film in vacuum ultraviolet (VUV) wavelength region theoretically and experimentally. The reflectance of Au films on quartz glass substrates with an approximately 2 nm binding layer of Ti, Cr, and Ir are estimated and fabricated. Their reflectance in the 115-140 nm wavelength region are measured continuously by the reflectometer located in the National Synchroton Radiation Laboratory. The testing results show that the addition of the binding layer indeed greatly enhances the interfacial adhesion of the Au layer to the quartz glass substrate, but it also exerts a considerably adverse impact on the reflectance of the Au layer in VUV wavelength region. In near normal incidence, the reflectance of the Au layer with a 2 nm thick binding layer is less than 20%, approximately 5% lower than those without the binding layer. The material used for the binding layer has little impact on the reflectance if this layer is thin enough.