[Fluorescence Characteristics and Source Analysis of DOM in Snowfall of Xi'an].

Fluorescence characteristics and sources of dissolved organic matter (DOM) in snowfall in Xi'an were studied by three-dimensional fluorescence spectroscopy, parallel factor analysis, and backward trajectory model, which provided a data basis for the analysis of the chemical composition and source of atmospheric organic pollutants. Results show that the DOC content of DOM was 0.88-10.92 mg·L-1. DOM mainly contained humus-like, fulvic acid-like, tryptophan-like, and tyrosine-like substances. The fluorescence intensity and the summed intensities of these substances exhibited significant positive correlations with the DOC and UV254 (P<0.01). The fluorescence index (FI), biological source index (BIX), and humic index (HIX) values of DOM during snowfall were 1.50-1.75, 0.87-1.25, and 1.11-1.97, respectively. FI was positively correlated with BIX and negatively correlated with HIX (P<0.05). During snowfall, the air mass transmission trajectories included the local transmission, long-distance transmission starting from Xinjiang (through Gansu and Ningxia), and medium-distance transmissions starting from Inner Mongolia (through Ningxia) and Shandong (via Henan), accounting for 38.78%, 24.04%, 19.87%, and 17.31% of the total, respectively. This indicates that the content or relative content of the DOM contained in the precipitation can be characterized by fluorescence intensities and their sums of the humic-like, fulvic acid-like, tryptophan-like, and tyrosine-like tyrosine. The DOM in snowfall had both biological and terrestrial characteristics, and belonged to a self-generated source with the newly produced organic matter or matter with stronger self-source characteristics. Local transmission had the most significant contribution to the source of snowfall DOM.

[Microbial Community Structure Shift During Bioremediation of Petroleum Contaminated Soil Using High Throughput Sequencing].

The shift in microbial community structure during the bioremediation of oil-polluted soil was analyzed by high-throughput sequencing. The results demonstrated obvious changes in the soil microbial community structure and diversity during bioremediation. The species richness and evenness of the microbial community decreased substantially due to the bioaugmentation treatment. Proteobacteria became the predominant phylum, with a relative increase in abundance from 37.44% to 87.44%. Pseudomonas was the most dominant genus, which increased in abundance from 2.99% to 76.37%. In the biostimulation treated soil, the relative abundance of Proteobacteria decreased from 37.44% to 10.90%, while the phylum Firmicutes increased from 9.16% to 35.32%. At the genus level, the relative abundances of Exiguobacterium and Promicromonospora decreased from 8.49% and 18.96% to 2.19% and 14.97%, respectively. Nocardioides and Bacillus became the dominant genera and increased from 5.56% and 0.29% to 28.95% and 22.70%, respectively. The results indicated that bioaugmentation substantially influenced the soil microbial diversity and community structure. Additionally, the biostimulation treatment maintained the balance in the soil microbial community structure. The stabilization of bacteria community structure is beneficial to petroleum biodegradation in the soil.

[Isolation, Identification and Degradation Characteristics of a 17ß-estradiol Degrading Strain Fusarium sp. KY123915].

A 17ß-estradiol (E2) degrading strain (designated as Wu-SP1) was isolated from the activated sludge collected from a wastewater treatment plant (WWTP) in Xi'an. The strain was identified as Fusarium sp. according to 18S rDNA sequence and phylogenetic analysis. The optimal pH and temperature for E2 degradation were 6 and 30℃, respectively. Under these conditions, the E2 biodegradation rate of 2 mg·L-1 E2 amounted to 92.5% within 48 h by this strain. The kinetics of E2 degradation by the strain KY123915 were in good accord with the first-order equation, with the concentration ranged from 10 to 500 mg·L-1. UV spectrum analysis showed the strength of maximum absorption of metabolites became weak compared to E2, indicating that E2 may be degraded via estrone (E1) by Fusarium sp. KY123915.

[Remediation of Petroleum-Contaminated Soil Using a Bioaugmented Compost Technique].

Bioaugmented compost was created by inoculating petroleum-degrading bacteria into mature compost. The petroleum hydrocarbon degradation efficiencies were investigated by applying this enhanced compost to petroleum-contaminated soil under low temperatures. The results showed that the degrading bacteria can be enriched in the mature compost. After 30 d of remediation, the removal efficiency of TPH, alkanes, and PAHs in the soil was 27.0%, 19.6%, and 10.0%, compared to natural attenuation (CK), which was 4.5%, 9.5%, and 2.3%, respectively. In response to remediation, the relative abundance of Proteobacteria and Actinobacteria phyla decreased from 53.4% and 25.9% to 48.9% and 14.1%, respectively, and Bacteroidetes phylum increased from 5.0% to 24.5%. At the genus level, the relative abundance of Acinetobacter and Pseudomonas increased from 0.02% and 3.4% to 15.2% and 4.6%, respectively. The results indicated that the bioaugmented compost may efficiently facilitate and speed up the bioremediation of petroleum-contaminated soil under low-temperature conditions. Soil microbial diversity and structure of microbial communities are sensitive to the remediation.

[Echinococcosis prevalence in elderly population from Haiyan County of Qinghai Province].

Echinococcus infection in elderly population (60-87 years old) was investigated by serological assay, medical imaging and epidemiology history in August, 2008. A total of 234 subjects from different nationalities were examined. Seven cases were serologically positive for echinococcosis and confirmed by medical imaging. Out of 30 suspected sera-positive cases, 3 were positive by medical imaging. There were 10 confirmed echinococcosis cases with a positive rate of 4.3%. There was significant difference on the prevalence among different towns (P < 0.05), but no significant statistical difference on the prevalence among nationalities, careers and sex. The prevalence in females (4.8%) was higher than that of males (3.6%).

[Clinical study on effect of fluoxetine combined with Chinese medicine or tibetan drugs in treating senile depression in plateau district].

OBJECTIVE: To compare the ettect and side-ettect of fluoxetine and combination of fluoxetine and Chinese or Tibetan medicine in treating senile depression in plateau district. Methods Ninety patients with diagnosis of senile depression conformed to CCMD-3 standard, in plateau district of 2260 - 3200 m altitude were randomly divided into three groups and treated with fluoxetine (group A), fluoxetine plus Sanpu Xinnao Xin granule (group B) and fluoxetine plus Xiaoyao pill (group C), respectively, 30 cases in each group. Therapeutic effects were evaluated with Hamilton' s depressive scale (HAMD) and treatment emergent symptom scale (TESS) after 6 weeks treatment. RESULTS: There was no significant difference in the therapeutic effects between the three groups. The adverse reaction in Group B and C was less than that in Group A (P<0.01). Conclusion Sanpu Xinnao Xin granule and Xiaoyao pill can raise the tolerance of patients with senile depression in plateau area against the adverse reaction of fluoxetine.