Tongji University

About: Tongji University is a education organization based out in Shanghai, China. It is known for research contribution in the topics: Computer science & Population. The organization has 76116 authors who have published 81176 publications receiving 1248911 citations. The organization is also known as: Tongji & Tóngjì Dàxué.

A Comprehensive Census of Microbial Diversity in Hot Springs of Tengchong, Yunnan Province China Using 16S rRNA Gene Pyrosequencing

Abstract: The Rehai and Ruidian geothermal fields, located in Tengchong County, Yunnan Province, China, host a variety of geochemically distinct hot springs. In this study, we report a comprehensive, cultivation-independent census of microbial communities in 37 samples collected from these geothermal fields, encompassing sites ranging in temperature from 55.1 to 93.6°C, in pH from 2.5 to 9.4, and in mineralogy from silicates in Rehai to carbonates in Ruidian. Richness was low in all samples, with 21–123 species-level OTUs detected. The bacterial phylum Aquificae or archaeal phylum Crenarchaeota were dominant in Rehai samples, yet the dominant taxa within those phyla depended on temperature, pH, and geochemistry. Rehai springs with low pH (2.5–2.6), high temperature (85.1–89.1°C), and high sulfur contents favored the crenarchaeal order Sulfolobales, whereas those with low pH (2.6–4.8) and cooler temperature (55.1–64.5°C) favored the Aquificae genus Hydrogenobaculum. Rehai springs with neutral-alkaline pH (7.2–9.4) and high temperature (>80°C) with high concentrations of silica and salt ions (Na, K, and Cl) favored the Aquificae genus Hydrogenobacter and crenarchaeal orders Desulfurococcales and Thermoproteales. Desulfurococcales and Thermoproteales became predominant in springs with pH much higher than the optimum and even the maximum pH known for these orders. Ruidian water samples harbored a single Aquificae genus Hydrogenobacter, whereas microbial communities in Ruidian sediment samples were more diverse at the phylum level and distinctly different from those in Rehai and Ruidian water samples, with a higher abundance of uncultivated lineages, close relatives of the ammonia-oxidizing archaeon “Candidatus Nitrosocaldus yellowstonii”, and candidate division O1aA90 and OP1. These differences between Ruidian sediments and Rehai samples were likely caused by temperature, pH, and sediment mineralogy. The results of this study significantly expand the current understanding of the microbiology in Tengchong hot springs and provide a basis for comparison with other geothermal systems around the world.

Biodiversity and biodiversity conservation in Yunnan, China

Abstract: Yunnan, an inland province at a low latitude and high elevation, lying between 21degrees09'-29degrees15' N and 97degrees32'-106degrees12' E in southwestern China, has a vast territory with diversified and unique nature resources. There are more than 18 000 high plant species (51.6% of China's total) and 1836 vertebrate species (54.8% of China's total) living in Yunnan on a land area of 39.4 x 10(4) km(2), i.e., only 4.1% of China's total. Among 15000 seed plants found in Yunnan there are 151 rare and endangered plant species (42.6% of China's protected plants). Out of 335 China priority protected wild animals, Yunnan has 243 species, accounting for 72.5% of China's total, 15% of which are species endemic to Yunnan. However, Yunnan's biodiversity is faced with the menace of excessive exploitation of resources and changes in environmental conditions caused by the activities of an expanding human population. This paper discusses the background, the composition, and the structure of Yunnan's biodiversity. Its biodiversity fragility and the threatened situation are also discussed. Suggestions and recommendations on the strategy and actions of Yunnan biodiversity conservation and sustainable development are proposed.

Carbon-dot-based ratiometric fluorescent probe for imaging and biosensing of superoxide anion in live cells.

Abstract: In this article, a ratiometric fluorescent biosensor for O2•– was developed, by employing carbon dots (C-Dots) as the reference fluorophore and hydroethidine (HE), a specific organic molecule toward O2•–, playing the role as both specific recognition element and response signal. The hybrid fluorescent probe CD-HE only emitted at 525 nm is ascribed to C-Dots, while HE was almost nonfluorescent, upon excitation at 488 nm. However, after reaction with O2•–, a new emission peak ascribed to the reaction products of HE and O2•– was clearly observed at 610 nm. Meanwhile, this peak gradually increased with the increasing concentration of O2•– but the emission peak at 525 nm stayed constant, leading to a ratiometric detection of O2•–. The inorganic–organic fluorescent sensor exhibited high sensitivity, a broad dynamic linear range of ∼5 × 10–7–1.4 × 10–4 M, and low detection limit down to 100 nM. The present probe also showed high accuracy and excellent selectivity for O2•– over other reactive oxygen species (ROS)...