[Characteristics of Water Extractable Organic Nitrogen from Erhai Lake Sediment and Its Differences with Other Sources].

The 47 samples from Erhai Lake surface sediments were collected in different seasons. The distribution and structure characteristics of sediment water extractable organic nitrogen(WEON) were investigated by using the combined techniques of UV-Vis absorption and three-dimensional excitation-emission matrix spectra(3DEEMs). The differences in DON of various sources(overlying water, pore water, inflow Rivers and wet deposition) were explored to analyze its effects on sediment.

[Compositional Characteristics of Sediment Dissolved Organic Nitrogen in Typical Lakes and Its Relationship on Water Trophic Status].

UV-Vis absorbance, fluorescence, and Gas Chromatography Mass Spectrometry (GC-MS) were applied to the comparative study on sediment dissolved organic nitrogen (DON) in five typical lakes (Erhai lake, Dianchilake, Poyang lake, Wuhan Dong lake, and Taihu lake) in different lake regions with different nutrition status, revealing the relationship between structural and compositional characteristics of sediment DON and trophic level of lakes. The obtained results showed that: ①Structure of lake sediment DON in Yungui Plateau region is more stable, compared with those in Eastern Plain region, indicating its lower bioavailability. ②In Yungui Plateau region, the source and compositional characteristics of sediment DON weremore complex in Dianchi lake (a seriously polluted lake), and its sediment DON bioavailabilitywas relatively higher.

[Investigation of an outbreak of acute diarrhea caused by Human calicivirus].

Background: To survey a diarrhea outbreak in Guangan city and analyze the cause of the disease.

Methods: The population enrolled in the surveillance came from four different settings and was randomly sampled. Stool specimens collected from diarrhea patients were tested ordinarily for enteric bacteria and further examined for viral pathogens with PAGE, ELISA and RT-PCR.