[Characteristics of Cd, As, and Pb in Soil and Wheat Grains and Health Risk Assessment of Grain-Cd/As/Pb on the Field Scale].

In recent years, heavy metal pollution in farmlands has become increasingly serious because of human activities such as metal smelting, sewage irrigation, and road traffic in China. A field survey was conducted to investigate characteristics of Cd, As, and Pb in soil and wheat grains and assess the health risk of grain-Cd/As/Pb to humans on the fields scale. The farmland was influenced by smelter and sewage irrigation in the attitude and by road traffic in the horizon.

Ion-pairing liquid chromatography with on-line electrospray ion trap mass spectrometry for the structural analysis of N-unsubstituted heparin/heparan sulfate.

The rare N-unsubstituted glucosamine (GlcNH3(+)) residues in heparan sulfate (HS) have important biological and pathophysiological roles. In this study, a high-resolution method for the separation and analysis of N-unsubstituted disaccharides of heparin/HS is described. Four N-unsubstituted disaccharides, together with eight N-substituted species, can be well-separated by ion-pair reverse-phase ultra-performance liquid chromatography.

Preparation and characterization of heparin hexasaccharide library with N-unsubstituted glucosamine residues.

The rare N-unsubstituted glucosamine (GlcNH3(+)) residues in heparan sulfate (HS) have important biological and pathophysiological roles. Therefore, the ability to chemically generate a series of oligosaccharides, which have a similar structure to the naturally-occurring, GlcNH3(+)--containing oligosaccharides from HS, would greatly contribute to investigating their natural role in HS. In this study, a hexasaccharide library that possess GlcNH3(+) residues were prepared from the chemical modification of the fully sulfated dp6.