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1.
Sci Rep ; 8(1): 8060, 2018 05 23.
Article in English | MEDLINE | ID: mdl-29795300

ABSTRACT

This study presents analysis of four chimney samples in terms of glycerol dialkyl glycerol tetraether lipids (GDGTs), representing different growing stages of sulfide chimneys at the Deyin hydrothermal field, the southern mid-Atlantic ridge. The modified Bligh-Dyer method was used for lipid extraction and purification. GDGTs were analyzed with an Agilent 1200 series liquid chromatograph and 6460A triple quadrupole mass spectrometer. Our results showed that the intact polar GDGTs were more abundant than the core GDGTs in the 4 samples. The intact polar isoprenoidal GDGT-0 was the dominant composition (>70% of isoprenoidal GDGTs), indicating input of thermophilic Euryarchaeota. Most branched GDGTs were likely originated from the in situ thermophilic bacteria. However, the intact polar GDGTs in the sample at the late growing stage was similar to that in normal marine sediments, suggesting that the archaea mainly came from the planktonic Thaumarchaeota input. Our results suggested that the ratio of H-GDGTs to iGDGTs could be considered as a proxy to differentiated growing stages of a chimney. This study shed light on how to assess hydrothermal venting and sulfide chimneys in deep marine environments with a biomarker method in terms of different groups of GDGTs.

2.
Huan Jing Ke Xue ; 28(8): 1655-61, 2007 Aug.
Article in Chinese | MEDLINE | ID: mdl-17926389

ABSTRACT

The first-stage storage of the Three Gorges Project started on the 1st June, 2003 and ended on the 10th June, 2003. In order to investigate the influences of the Three Gorges Project on the Changjiang Estuary and adjacent area environment, a cruise was carried out from the 15th June, 2003 to the 25th June, 2003 to synthetically study the environment. Suspended matter concentrations (SMC) in different water layers at different sites were calculated and distributions of SMC were discussed combining with salinity and temperature of water based on recovered data. In results, SMC increase from surface to bottom in Changjiang Estuary and adjacent area. Suspended matters are enriched in the water over the river mouth bar and alongshore area which are located at the west of 123 degrees E. Compared to that before the storage, SMC are reduced obviously in the Changjiang course and south branch after the storage. For example, at the Xuliujing, SMC are reduced from 400 - 500 mg/L to 60.2 mg/L, and in the south branch, from 445 mg/L to 148 mg/L. In other areas, SMC do not show a significant change that they are both less than 10 mg/L in the surface player and 100 mg/L in bottom player. Generally, the distributed patterns of SMC in the investigation area after the storage are still similar to that before the storage.


Subject(s)
Environmental Monitoring/methods , Fresh Water/analysis , Particulate Matter/analysis , Seawater/analysis , Water Pollutants/analysis , China , Geologic Sediments/analysis , Rivers , Water Movements
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