[Characteristics of Cd Fluxe in Topsoil Around Typical Mining Area in Hezhou, Guangxi].

Guangxi is a typical geological high background area in southwest China, where carbonates, black rock series, basic-ultrabasic rock mass, and metal deposits (mineralized bodies) exhibit strong weathering into loam, resulting in higher cadmium (Cd) content in the soil than that in other areas of China. In order to investigate the degree of influence of mining activities on topsoil environmental quality in the area with high geological background, we chose a mining area and control area in Hezhou for this research and systematically carried out a comparative study on Cd transport routes and transport flux density in topsoil. The results showed that the average atmospheric dry and wet deposition flux densities of Cd in the soil of the mining area and control area were 1.

[Spatial Interpolation Methods and Pollution Assessment of Heavy Metals of Soil in Typical Areas].

It is important to choose the best spatial interpolation method to reflect spatial distribution features and evaluate soil heavy metal pollution. The spatial distribution of arsenic (As) and cadmium (Cd) concentrations in top soil samples from Hubei Province were studied by four frequently-used spatial interpolation methods, including inverse distance weighted (IDW), radial basis function (RBF), local polynomial interpolation (LPI) and ordinary kriging (OK). The interpolation precision and effect of the spatial distribution of the four methods were compared with the results of cross validation and spatial distribution, and the pollution was assessed by the geoaccumulative index (I) and indicator kriging (IK).

[Quantifying the influence of different matrices on Pb accumulation in the soil from Nanjing and suspended matter from the lower of the Yangtze River with Pb isotopic technique].

Lead pollution and its geochemical behavior have an influence on ecological environment and human health. It is of significance to study the characteristics and mechanism of Pb accumulation and to quantify the contributions of different environmental matrices to Pb accumulation in soils and river suspended matter in the representative fluvial delta area, such as the lower of the Yangtze River. The results showed that lead was enriched in the urban topsoil in Nanjing and the suspended matter in the lower of the Yangtze River.

Robust multi-type plasmid modifications based on isothermal in vitro recombination.

A robust strategy for multi-type plasmid modifications is developed based on the isothermal in vitro recombination technology, by which any combination of the sequence modifications can be efficiently achieved in plasmids at any desired position in a seamless manner. As an example, we showed that a plasmid modification with insertion of a GFP gene, deletion of a 623-bp fragment, and substitution of an ampicillin resistance gene by a kanamycin resistance gene was accomplished simultaneously by this method. Therefore, the isothermal in vitro recombination-based multi-type plasmid modification strategy is a useful approach for broad application prospects in molecular biology studies.