Vulnerability to Stress and Depression Risk Related to Occupational Exposure to Aluminum

Occupational exposure to aluminum was reported to be associated with various neurotoxic effects including cognitive impairment, depression, anxiety, and also Alzheimer’s disease. The purpose of the present study was to evaluate the level of vulnerability to stress in workers exposed to aluminum. The correlation between vulnerability to stress and depression was also investigated. This was a retrospective study that included 135 participants, 99 were exposed to aluminum, and 36 were not exposed to aluminum. Vulnerability to stress and depression was assessed using a self-rating scale developed in-house. Vulnerability to stress was reported in various degrees in a total of 84 participants, 69 (69.70%) participants from the exposed group and 15 (41.67%) participants from the control group. Out of the 84 participants with vulnerability to stress, 51 had depression also. Excellent resistance to stress was reported in 51 out of 135 participants, 30 (30.30%) in the exposed group and 21 (58.33%) in the control group. Out of the 51 participants with excellent resistance to stress, only 2 participants had depression. The results of the present study suggested that exposure to aluminum is correlated with vulnerability to stress. The level of vulnerability to stress is increasing with the level of exposure to aluminum. Furthermore, since vulnerability to stress is correlated with depression, higher exposure to aluminum might be a risk factor for depression.

Differential cell stress responses to food availability by the nestlings of Asian Short-toed Lark(Calandrella cheleensis)

Background:Timing of breeding season of temperate passerines has been considered to be adjusted to their food availability.There is little work to reveal the cell stress responses of the nestlings hatched asynchronized with the food abundance peak,which is important for understanding the physiological link between the timing of breeding and the fitness of offspring.Methods:Using gene expression level of blood HSP70 and HSP90 as indicators,we compared the cell stress response of Asian Short-toed Lark(Calandrella cheleensis)nestlings hatched under conditions of low,mid or high food(grasshopper nymph)availability in 2017.Results:Nymph biomass,sample time and interaction of these two factors significantly influenced the blood gene expression level of HSP70 and HSP90 of Asian Short-toed Lark nestlings.HSP70 and HSP90 gene expression levels of the nestlings at 14:00 were significantly higher than those at 5:00.At either 5:00 or 14:00,the gene expression levels of HSP70 and HSP90 increase with the decrease of nymph biomass.Conclusions:These results indicate that food availability is an important environment factor inducing cellular stress of Asian Short-toed Lark nestlings.The interactive effect of the nymph abundance and sample time on the HSPs response may be related with the daily temperature variation of the grassland.Over cell stress response may be one of physiological factor mediating the effect of food availability and the nestling’s fitness.

Effect of pre-deformation on the stress corrosion cracking susceptibility of aluminum alloy 2519

The effects of pre-deformation and strain rate on the stress corrosion cracking （SCC） behavior of aluminum alloy 2519 in air and in 3.5% NaCI water solution were investigated by means of slow strain rate tension （SSRT）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results indicate that the alloy is susceptible to SCC in 3.5% NaCI water solution and not in air. At the same pre-deformation, the alloy is more susceptible to SCC at 1.33 × 10^-5 s^-1 than at 6.66 × 10^-5 s^-1. Moreover, it is more susceptible to SCC at free pre-deformation than at 10% pre-deformation at the same strain rate. The number of 0 precipitated along the grain boundaries is reduced and distributed discontinuously, at the same time, the precipitate-free zones （PFZ） become narrow and the susceptibility to stress corrosion cracking is reduced after 10% pre-deformation.