[Analysis on Contamination Characteristics, Pollution Source Identification and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons of Groundwater in a Large Coking Plant Site of Province].

Polycyclic aromatic hydrocarbons (PAHs), as a highly toxic persistent organic pollutant, are commonly found in soil and water environments. In recent years, the pollution of PAHs in groundwater has attracted wide attention from scientists. To study the pollution characteristics and sources of polycyclic aromatic hydrocarbon in groundwater of the coking site, 16 PAHs priorly controlled by the US EPA were analyzed and discussed. In this study, we identified the contamination characteristics of PAHs in groundwater, analyzed the pollution sources of PAHs, and evaluated the ecological risk of PAHs in the coking site by combining statistical techniques, the positive matrix factorization (PMF) model, and risk quotient (RQ) methods. The results indicated that the total detection rate of PAHs in groundwater of the coking plant was 46.7%. The concentrations of PAHs in groundwater of the coking plant ranged from below the detection limit to 444.9 µg·L-1, with the average value of 1.88 µg·L-1. The concentration of PAHs in the groundwater of different production workshops was significantly different. The most polluted workshop was in the tar-refining area, and the concentration of 16 PAHs was 444.9 µg·L-1. Based on the PMF model, we identified the two primary contamination sources of PAHs in groundwater of the coking plant:① oil combustion and ② coal and biomass combustion and oil leakage. The contribution ratios of the two sources to PAHs of groundwater were 38.6% and 61.4%, respectively. The results of the ecological risk assessment indicated that Σ16PAHs in groundwater of the coking plant had high ecological risk, and the ecological risk of single PAHs in 53.4% of the groundwater sampling site was at a high ecological risk level. In conclusion, it is urgent to carry out the treatment and restoration of the groundwater environment in the coking plant site.

[Effects of curcumin on the recovery of hind limb function after spinal cord injury in rats and its mechamism].

OBJECTIVE: To investigate the effects of curcumin on motor function, and to explore the neuroprotective mechanism of curcumin after the spinal cord injury in rats. The study will theoretical and experimental evidence for curcumin's clinical treatment. METHODS: HI-0400 spinal cord impactor was used to prepare animal models of acute of spinal cord injury. One hundred and five clean and healthy rats were randomly divide into three groups:sham operation group (Sham) spinal cord injury group (SCI) and curcumin group (SCI+CUR). Intragastric administration was administrated after 30min of the spinal cord injury model, after 1 time a day, until the death. SCI+CUR group was intragastric administration with curcumin (100 mg/kg) of 0.5% carboxymethyl cellulose sodium, and Sham and SCI group were treated with the same dose of 0.5% carboxymethyl cellulose sodium. The motor function recovery of 3,7,14,21 and 28 days after spinal cord injury were evaluated by basso,beatlie,bresnahan (BBB) score. The spinal cord tissue and blood samples were collected at postoperative 12 h, 1 d, 3 d and 7 d respectively, NF-kappa B was detected by immunofluorescence, Bcl-2, Bax and Caspase-3 were detected by immunohistochemistry. The expression of Bcl-2 and Bax was detected by Elisa. RESULTS: The statistic difference of BBB score between SCI group and CUR group in 3 day was not statistically significant. It was found that the 7,14,21 and 28 days BBB score in CUR group were statistically significant higher than that in SCI group(P<0.05).The expression of inflammatory factor NF-kappa B appeared in 12 h after spinal cord injury, 1 day peaked and 3 days decreased. In SCI+CUR group, the expression of NF-kappa B at each time point was similar to the SCI group, and there was a difference between group SCI+CUR and SCI group in 1day.There was no obvious staining of Bax and Bcl-2 in Sham group. The staining of Caspase-3 and Bax in SCI+CUR group was significantly weaker than that in SCI group, while Bcl-2 was stronger. CONCLUSIONS: Curcumin can promote the recovery of hindlimb motor function after spinal cord injury in rats.The mechanism is through inhibition of NF-K B to prevent inflammation; And inhibition the expression of Bax and Caspase-3, and promotion the expression of Bcl-2 to prevent apoptosis, so as to accelerate the recovery of motor function in the rats after spinal cord injury.