[Hydrochemical Characteristics and Possible Controls of the Surface Water in Ranwu Lake Basin].

To study the chemistry of surface water and potential control measures in the Ranwu Lake basin, 19 samples were collected from Ranwu Lake in 2019. Conventional hydrochemical techniques and statistical analysis methods (descriptive statistics, the Gibbs figure, ion ratio, Piper triangular diagrams) were applied to better understand the solute geochemistry and surface water hydrochemistry in the Ranwu Lake catchment. Surface water in the Ranwu catchment is slightly alkaline (pH of the samples ranged from 7.54 to 8.48 with an average value of 8.06). The concentrations of total dissolved solids (TDS) in the water range from 59.89 to 96.75 mg ·L-1 with an average of 79.98 mg ·L-1, the total dissolved solids of all samples are less than 100 mg ·L-1 and belong to fresh water. The TDS are dominated by Ca2+, Mg2+, HCO3-, and SO42- in the Ranwu Lake. The ion concentrations in the lake water samples are in the order of Ca2+ > Mg2+ > Na+ > K+. The concentrations of Na+and K+are very low. Ranging from 0.5 to 1.21 mg ·L-1, with an average value of 0.58 mg ·L-1, the equivalent concentration of Ca2+ accounts for 63.3% to 76.2% of total cations with an average value of 67.2%. The equivalent concentration of Mg2+ accounts for 23.4% to 36.2% of total cations with an average value of 31.4%. Ca2+ and Mg2+ account for 98.5% of total cations. The main anions were HCO3- and SO42-. The equivalent concentration of HCO3- accounts for 74.31% to 84.29% of total anions with an average value of 78.21%. The equivalent concentration of SO42- accounts for 9.59% to 19.37% of total anions with an average value of 15.34%. HCO3- and SO42- together account for 93.55% of total anions on average. All the water samples fall in the water-rock interaction field, which suggests that the weathering of rocks primarily controls the major ion chemistry of groundwater in this area. Solutes are mainly derived from carbonate weathering and silicate weathering. The role of cation exchange in the geochemical process of the lake and the influence of human activities on the lake are found to be weak.

[Effects of maize straw returning on arbuscular mycorrhizal fungal community structure in soil]. / çŽ‰ç±³ç§¸ç§†è¿˜ç”°å¯¹åœŸå£¤ä¸›æžèŒæ ¹çœŸèŒç¾¤è½çš„å½±å“.

To understand the effects of agricultural management activities on soil arbuscular mycorrhizal (AM) fungi diversity, the high-throughput sequencing based on Illumina MiSeq platform, and the fatty acids fingerprints were used to examine the effects of maize straw returning on soil arbuscular mycorrhizal fungi. The relationships between AM fungal community composition, AM fungal biomass and soil factors after maize straw returning were examined for four continuous years. A total of 2430 operational taxonomic units (OTUs) of AM fungi were classified into 10 genera and 143 species, respectively, which belonged to 1 phylum, 3 classes, 4 orders, 8 families. There was no significant difference in AM fungal community richness (Chaoles index and ACE index) and diversity (Shannon, Simpson diversity indices) in different treatments. Paraglomus and Glomus were dominant genera among all AM fungal communities. With the increase of the maize straw returned amounts, the abundance of Glomus reduced. Under the treatments of 3000 and 9000 kg·hm-2 straw returned, the abundance of Glomus and Acaulospora had significant differences with the control (0 kg·hm-2). Compared with the control, there were significant differences between Archaeospora, Paraglomus and Glomus in the treatment of 3000 kg·hm-2 straw returned. Results from non-metric multi-dimensional scale (NMDS) analysis showed that under 9000 and 12000 kg·hm-2 straw returning treatments, the difference between the ß diversity of soil AM fungi and the spatial distance of controls was farther apart than the other treatments. The effect of straw returning on the ß diversity of AM fungi was significant. The multivariate analysis results revealed the relationship of the spatial variation between the soil physicochemical properties and AM fungi richness and diversity could be explained at 82.8% cumulative variables. The total nitrogen and available nitrogen were the most important factors driving soil microbial communities biomass marked by PLFAs and AM fungal biomass (NLFAs). The continuous maize straw returning to the field changed the genera composition of AM fungi. With the increases of straw returning amounts, the specific species of AM fungi decreased and the similarity between AM fungi community composition decreased. Straw returning increased soil AM fungi biomass and its contribution to soil total microbial biomass.

[Effects of PRF and released three growth factors on migration of rat adipose tissue-derived stem cells].

PURPOSE: To analyze the effects of PRF and released three growth factors on migration of rat adipose tissue-derived stem cells and to investigate the mechanism of migration. METHODS: The inguinal adipose tissue of rat was excised at aseptic condition to obtain primary ADSCs by enzyme digestion. Multi-directional differentiation was used to identify the ADSCs. PRF membrane was acquired through one time centrifuge. The cell migration was examined by Transwell assay and wound healing assay. The mRNA expression of MMP2 and MT1-MMP was tested by real-time PCR. Statistical analysis was performed using SPSS 13.0 software package. RESULTS: Cell migration test showed that the migration of rat ADSCs in PRF group were significantly higher than those in the negative group（P<0.05） and inhibitor group（P<0.05）. The ADSCs migration effects in three growth factors group at different concentrations showed significant difference（P<0.05）. Real-time PCR showed that gene expressions of MMP2 and MT1-MMP were significantly higher in PRF group than control group (P<0.05). PCR showed that gene expressions of MMP2 and MT1-MMP were significantly higher in three growth factors group than control group (P<0.05). CONCLUTIONS: PRF and three growth factors consistently enhanced the migration of rat ADSCs in a dose-response manner. The migration increase of rat ADSCs may be associated with the up-regulation of MMP2 and MT1-MMP gene expression.

[Distribution of arsenic in surface water in Tibet].

This research was aimed on studying the arsenic distribution of water in Yarlung Zangbo and Singe Zangbo basins in Tibet. Results showed that arsenic concentrations were different in different types of the water. The sequence of arsenic concentration from high to low was hot spring water (4920 microg x L(-1) +/- 1520 microg x L(-1), n =2), salt lake water (2180 microg x L(-1) +/- 3840 microg x L(-1), n =7), well water (194 microg x L(-1), n = 1), freshwater lake water (163 microg x L(-1) +/- 202 microg x L(-1), n =2) and stream water (35.5 microg x L(-1) +/- 57.0 microg x L(-1), n=74). The high arsenic concentration in surface water in Singe Zangbo and the upstream of Yarlung Zangbo were found. The average concentration of arsenic in water from Singe Zangbo (58.4 microg x L(-1) +/- 69.9 microg x L(-1), n = 39) was significantly higher than that from Yarlung Zangbo (10.8 microg x L(-1) +/- 16.9 microg x L(-1), n = 30). Arsenic concentration in 43.2% of stream water samples and all of the hot springs, saline lakes and well water were higher than 10 microg x L(-1). Yarlung Zangbo and Singe Zangbo are important sources of drinking water for the local people. There is a high risk for the local people who may suffer from chronic arsenic poisoning.

[The mechanism of MAb225 regulating radiosensitivity of Tca8113 cell].

PURPOSE: The objective of this study was to investigate the mechanism of MAb225 regulating radiosensitivity of Tca8113 cells. METHODS: Tca8113 cells were treated with MAb225 of different concentrations. The apoptosis rate was analysed by FCM and bi-fluorescence stain, the repair of DNA damage after radiation was analysed by single cell gel electrophoresis, cells redistribution in each phase of cell cycle was analysed by FCM, and GSH level of cell were assessed by spectrophotometer. RESULTS: Radiation alone (6 Gy) and MAb225 alone (0.5 microg/ml) produced a 2-fold induction of apoptosis respectively, whereas exposure to MAb225 (0.5 microg/ml) combination with 6 Gy of radiation induced apoptosis 5-6 fold, compared to untreated controls (F test). The length of comet tail of cells which treated with MAb225 was significantly longer than that of the control cells (t test, P<0.05). The percentage of cells in S phase was significantly decreased in MAb225 treated cells. Intracellular GSH level of MAb225 treated cells was significantly lower than that of untreated cells (t test, P<0.05). CONCLUSION: MAb225 increased the radiosensitivity of Tca8113 cells by enhancing radiation-induced apoptosis, downregulating S phase percentage, inhibiting DNA repair after radiation and decreasing GSH level.

[Effect of MAb225 on radiosensitivity of Tca8113 tongue squamous cell carcinoma].

OBJECTIVE: The purpose of this study was to invest the effect of epidermal growth factor receptor monoclonal antibody MAb225 on radiosensitivity of tongue squamous cell carcinoma cell Tca8113. METHODS: Tca8113 cells were treated with different concentrations of MAb225. Radiation dose survival curve was generated from clonogenic survival assay. SERPD0 and survival faction (SF2) was analysed by single hit multi-target (SHMT) radiobiological model using RADMEDIC software. Nude mice with Tca8113 tumor xenografts were treated with MAb225, radiation treatment or both of them. Tumor responses were assessed by tumor growth delay, and t test was used for statistical analysis. RESULTS: MAb225 enhanced the radiosensitivity of Tca8113 cells. SERD0 of Tca8113 cells treated with 0.5 mg/L MAb225 was 1.23. The survival fraction of cells treated with MAb225 was significantly decreased. Tumor radioresponse could be enhanced by MAb225 (P < 0.05). CONCLUSION: MAb225 could enhance radiosensitivity of tongue squamous cell carcinoma cell.

[Inhibiting effect of EGFR monoclonal antibody on proliferation of oral squamous cell carcinoma].

OBJECTIVE: To investigate the inhibiting effect of epidermal growth factor receptor (EGFRmAb) on proliferation of oral squamous cell carcinoma (SCC). METHODS: Tca8113 squamous cell carcinoma cell line was treated with different concentration of EGFRmAb. Cell growth curve, clone inhibition rate, cell cycle redistribution and the expression of p27kip1 were analyzed. RESULTS: EGFRmAb inhibited proliferation of oral SCC, leaded to elevation of cell proportion of G1phase cell, decreased the proportion of S phase cell and upregulated the express of p27kip1. CONCLUSION: EGFRmAb inhibited the proliferation of oral SCC, which related with G1 phase arrest of tumor cell.