Objective To provide scientific basis for prevention of source water pollution and minimization of impacts of biological pollution on drinking water quality.Methods The source water and finished water were determined based on the National Sanitary Method for Determination of Drinking Water(GB5750-1985),the sanitary quality of source water was classified based on the National Standard for Environmental Quality of Surface Water(GHZB1-1999),the sanitary quality of finished water was evaluated based on the National Sanitary Standard for Drinking Water(GB5749-1985).Results 36.8% of the accidents of source water pollution were induced by biological pollution,which mainly occured in rivers and lakes. Conclusion The important countermeasures for the minimization of source water biological pollution were to improve the process of water treatment and to develop the deep water treatment for conventional water treatment.

BACKGROUND: Emerging studies have focused on cell transplantation. Schwann cells (SCs) can secrete various neurotrophic factors and improve local environment around injury. Plenty of documents have demonstrated that SCs could promote functional recovery following spinal injury. Many transplanting methods are available for treating spinal cord injury, and the intravenous cell transplantation is profitable for easy operation and avoidance of additional trauma. OBJECTIVE: To investigate the effects of intravenous transplantation of SCs on spinal cord injury in rats. METHODS: The bilateral sciatic nerves of Wistar rats were separated in vitro, cultured by tissue clot method, identified by S-100 and labeled by Hoechst33342. Sixty rat models with T10 spinal cord injury were prepared using impactor model- II type weight drop apparatus. Then the injured rats were randomly divided into 3 groups: blank control, DMEM control and SCs transplantation groups. No treatment was performed in the blank control group. Totally 1 mL DMEM and or SCs was injected into rats of DMEM control and SCs transplantation groups by tail vein respectively. Basso Beattie Bresnahan (B6B) scores were performed at 1 day before and 1, 3 days, 1 week and weekly after operation. The migration of transplanted SCs was observed at 2 weeks and 4 after transplantation. The expressions of glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) were detected by haematoxylin-eosin staining and immune-fluorescence staining.RESULTS AND CONCLUSION: The purity of SCs reached 95%. Hoechst33342 positive cells were observed throughout the injured and the nearby region of spinal cord at 1, 2, and 4 weeks after transplantation. The statistical difference of BBB score among the SCs transplantation, blank control, and the DMEM control groups displayed at 4 weeks after transplantation (P < 0.05), and the BBB scores of the SCs transplantation were higher than other groups. Haematoxylin-eosin staining showed the cavity formed in each group at 8 weeks after transplantation, but the area of SCs transplantation was smaller than that of the blank control and DMEM control groups. The immunofluorescence staining indicated that the expression of GFAP were more intense in the blank control group and DMEM control than SCs transplantation (P < 0.05), while the expression of NSE was more intense in SCs transplantation than other groups (P< 0.05). It implied that intravenous transplantation of SCs promotes regeneration of axon and improves neurological functions after spinal cord injury in rats.

Objective To investigate the promoter methylation status,mRNA expression and clinical significance of insulin-like growth factors 2 (IGF2)/H19 genes in term infants smaller than gestational age (SGA) infants whose mothers had gestational diabetes mellitus (GDM).Methods The clinical data of 20 full-term infants whose mothers had GDM (group 1),23 cases of full-term SGA infants whose mothers did not have GDM (group 2) and 21 full-term health infants whose mothers did not have any diseases during pregnancy(group 3) were collected,and all infants were delivered in Changsha Hospital for Maternal and Child Health Care between January 2015 and January 2018.The promoter methylation levels of IGF2/H19 gene from peripheral blood of 3 groups were detected by the method of Bisulfite sequencing polymerase chain reaction (PCR) (BSP),and IGF2/H19 mRNA was detected by real-time transcription RT-PCR method.Results The promoter methylation rates of IGF2/H19 in peripheral blood of infants were (22.51 ±5.29)％,(28.94 ±2.51)％ in group 1,(27.84 ±4.63)％,(34.58 ±6.97)％ in group 2,(37.47 ±7.84) ％,and (40.26 ±5.33) ％ in group 3.The promoter methylation rate of IGF2 and H19 in group 1 were significantly lower than those in group 2 and group 3,and the differences were statistically significant(all P ＜ 0.05).The relative expression of IGF2/H19 mRNA in peripheral blood of group 3 (1.04 ±0.12,1.01 ±0.13) were significantly higher than those in the group 1,and the differences were statistically significant (all P ＜ 0.05),and there were no significant differences in relative expression of IGF2/H19 between the group 1 and the group 2 (1.30 ±0.10,1.29 ±0.11) (all P ＞ 0.05).Conclusions The abnormal promoter methylation status and mRNA expression levels of IGF2/H19 gene methylation frequency and mRNA abnormalities may occur in infants less than gestational age infants if exposed to hyperglycemia during pregnancy,which may be one of the causes of intrauterine growth retardation and may affect its later growth and development.

Objective: To investigate the effect of hypertensive disorder complicating pregnancy (HDCP) on the mortality and early complications of premature infants. Methods: The general clinical data of preterm infants with gestational age 24-36^{+ 6} weeks were collected from the cooperative units in the task group from January 1, 2013 to December 31, 2014.According to the severity of HDCP, the infants were divided into 4 groups: HDCP group, preeclampsia group, eclampsia group and non HDCP group, the mortality and major complications of preterm infants were compared, and the influencing factors were analyzed. Results: The mortality rate of preterm in the HDCP group was significantly higher than that of non HDCP group, and there was statistical significance (χ²=9.970, P=0.019). Eclampsia had a highest fatality rate (4.8%) in the early stage, compared with non HDCP group (2.2%), and the difference was statistically significant.Comparison of HDCP group (1.8%) and eclampsia group (3.2%) suggested that there was no statistically significant difference.The incidence of respiratory distress syndrome (RDS) in preterm in HDCP group was significantly higher than that of non HDCP group, and there was statistical significance (χ²=13.241, P=0.004). Eclampsia group showed the highest incidence (35.4%), compared with non HDCP group (16.2%), the difference was statistically significant, but compared with HDCP group (19.9%), preeclampsia group (17.1%), there was no significant diffe-rence.The incidence of bronchopulmonary dysplasia (BPD) in preterm in HDCP group was significantly higher than that of non HDCP group (χ²=9.592, P=0.022), the highest incidence showed up in eclampsia group (9.7%), compared with non HDCP group (2.0%) and HDCP group (1.7%), the difference was statistically significant.But there was no statistically significant difference, compared with preeclampsia group.As the degree of HDCP aggravated, the incidence of BPD gradually rose.There was no significant impact on necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH) and sepsis of HDCP (χ²=7.054, 7.214, 0.358, 3.852; P=0.070, 0.065, 0.949, 0.278). Considering the overall outcome of the child, that was, whether the child died or survived, he had at least one complication, and HDCP had an effect on it (χ²=15.697, P=0.001), so the incidence increased while the degree of HDCP rose gradually.After adjusting gestational age, birth weight, sex, way of delivery, placental abruption and front placenta, prenatal hormonal, gestational diabetes, neonatal asphyxia and other factors, the results displayed that HDCP was the factor leading to the death of premature baby (OR=2.159, 95%CI: 1.093-4.266), and comparison between preeclampsia and eclampsia showed no statistical difference (P=0.714, 0.389); HDCP had no significant influence on RDS, BDP, ICH, NEC, ROP and sepsis. Conclusions HDCP leads to increased risk of premature death, but also leads to the increased incidence of RDS and BPD, but it had no obvious effect on NEC, ROP, IVH, sepsis and other complications.