Effects of Combination of 1,25(OH) 2D 3 and TLR-4 Inhibitor on the Damage to HaCaT Cells Caused by UVB Irradiation.

Objective: Vitamin D and Toll-like receptor-4 (TLR-4) inhibition are involved in the protection of keratinocytes. The effects of combination of 1,25(OH) 2D 3 and TLR-4 inhibitor on the protection of keratinocytes against ultraviolet radiation B (UVB) irradiation remain unclear. This study was undertaken to explore the effects of combination of 1,25(OH) 2D 3 and TAK-242 (TLR-4 inhibitor) on the damage to HaCaT cells caused by UVB irradiation. Methods: In vitro, HaCaT cells were treated with 1,25(OH) 2D 3 or/and TAK-242 prior to UVB irradiation at the intensity of 20 mJ/cm 2, then the production of reactive oxygen species (ROS), cell migration, apoptosis of cells, and the expression of oxidative stress, endoplasmic reticulum stress, and apoptosis related proteins were determined. Results: Compared with the HaCaT cells treated with 1,25(OH) 2D 3 or TAK-242, the cells treated with both 1,25(OH) 2D 3 and TAK-242 showed, 1) significantly lower production of ROS ( P < 0.05); 2) significantly less apoptosis of HaCaT cells ( P < 0.05); 3) significantly lower expression of NF- κB, Caspase-8, Cyto-C, Caspase-3 ( P < 0.05). Conclusion: The combination of 1,25(OH) 2D 3 and TAK-242 could produce a better protection for HaCaT cells via inhibiting the oxidative stress, endoplasmic reticulum stress and apoptosis than 1,25(OH) 2D 3 or TAK-242 alone.

[Hygroscopic Properties and Closure of Aerosol Chemical Composition in Mt. Huang in Summer].

The hygroscopic properties of aerosol have significant impact on aerosol optical properties, cloud condensation nuclei activity and human health. Aerosol particles growth factor and size-resolved ions chemical compositions were monitored in Mt. Huang. The hygroscopic properties of aerosol particles in Mt. Huang were studied. The results demonstrated that between 70 nm and 230 nm, the mass fractions of (NH4)2SO4, organic matter and other insoluble materials were the highest. The fraction of NH4NO3 standed in the medium. The fraction of NH4HSO4 was the lowest. The fraction of inorganic salts increased with increasing particle diameter. Aerosol particles during daytime had stronger hygroscopicity than that at night and the hygroscopicity of aerosol became stronger when its diameter increased. The calculation hygroscopic parameter κ of aerosol particles showed similar diurnal variation characteristics to the observation κ. Good closure could be achieved when ZSR mixing rule was used based on aerosol chemical composition to calculate aerosol hygroscopic parameter κ and the coefficient of determination was 0.60 for all the diameters.

[Effects of Relative Humidity and Aerosol Physicochemical Properties on Atmospheric Visibility in Northern Suburb of Nanjing].

To understand the effects of relative humidity (RH) and aerosol physicochemical properties on the atmospheric visibility in autumn and winter in northern suburb of Nanjing, the relationships between meteorological elements, particulate matter and visibility were analyzed with the data of meteorological elements, aerosol particle spectra, particulate matter concentration and chemical composition. The average visibility was 4.76 km in autumn and winter in northern suburb of Nanjing. There was a certain negative correlation between the particulate matter concentration and the visibility, especially the influence of fine particles on the visibility was more remarkable. The occurrence frequencies of low visibilities showed an increasing trend with the increasing concentration of fine particles and RH. When the visibility decreased from 5-10 km to <5 km, the mass concentrations of PM10 and PM2.5 increased by 7.56% and 37.64%, respectively. Meanwhile, the mass concentrations of SO4(2-) and NO3-increased significantly. Effects of aerosol particle number concentration on the visibility were related with RH. Aerosol number concentration with diameters ranging from 0.5 microm to 2 microm increased slowly with the increase of RH, while those ranging from 2 microm to 10 microm decreased. The correlation analysis between the aerosol surface area concentration and the visibility showed that RH and fine particles between 0.5 microm and 2 microm were the main factors which caused the decrease of atmospheric visibility in autumn and winter in northern suburb of Nanjing.