Geochemical Significance of Biomarkers in the Methane Hydrate-Bearing Sediments from the Shenhu Area, the South China Sea.

Biomarkers from methane hydrate-bearing sediments can provide vital evidence for microbial activities associated with methanogenesis and their relation to the formation of methane hydrates. However, the former mainly focus on intact polar lipids from these microorganisms, and rarely investigate molecular hydrocarbons such as acyclic isoprenoids and hopanes so far. In this work, the composition of biomarkers in the methane hydrate-bearing sediments in cores SH2B and SH7B from the Shenhu area, the South China Sea (SCS) were identified by gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC-TOFMS). The occurrence of unresolved complex mixtures (UCMs) and 25-norhopane indicate that the organic matters in methane hydrate-bearing sediments underwent a high degree of biodegradation. Although specific biomarkers for methanogens were not identified, the UCMs, 25-norhopane, pristane, phytane, and hopanes can still indicate the microbial activities associated with methanogenesis. These molecular signals suggest that diverse microorganisms, particularly methanogens, were quite vigorous in the methane hydrate-bearing sediments. Further, the biomarkers identified in this study can also be steadily detected from deep oil/gas reservoirs. Considering numerous adjacent oil/gas reservoir systems, fault systems, and mud diapers occurred in the SCS, it can be inferred that microbial activities and deep oil/gas reservoirs may have jointly contributed to the formation of methane hydrate deposits in the SCS.

[Resources and application of She's nationality wild medicinal plants].

To make a thorough investigation of the common She's nationality wild medicinal plants resources in our country, including the species, the distribution, the folk application and the endemic medicinal plant species, Field surveyed was conducted with 25 She people mainly lived area (county, district or city) throughout the country, the folk prescription and treatment cases provided by She's medical personnel, the drug usage and dosage, the commonly used traditional She's medicine and drug samples were collected. And the distribution, growing environment of these plants were investigated, their characteristics, photographs, GPS data and track were record , and the fresh wax leaf or plants specimens were collected. In total 1 600 varieties of folk medicine of She's nationality, 450 disease names and 1 016 prescriptions were collected. 520 kinds of these medicinal plants were commonly used, growing mainly distributed in the southeastern China, about 200 meters above sea level to 1 500 meters. There are 5 First-Grade State protection wild plants (medicinal), 15 second-Grade State protection wild plants (medicinal), and 11 She characteristic medicinal plants in our study, they belong to 144 families, 312 genera 494 species, 2 subspecies, 17 varieties, 3 forms and 1 cultivated varieties of She's nationality. Folk medicine usage is different from the traditional Chinese medicine and ethnic medicine. This survey finds out the common She's nationality wild medicinal plants resources in China, including the species, the distribution, the folk application and commonly used drugs, and found the rare and endangered medicinal plants and the She's nationality endemic medicinal plants, which provides a basis for further development and use the traditional She's medicine resources.