Research development of endocrine disrupting chemicals (EDCs) in water in China.
More and more importance has been attached to the problem of endocrine disrupting chemicals (EDCs) since 1960s. This article elaborates the recent research progress of EDCs in water and the trends in the near future in China.
[The concentration and source of atrazine residue in water of Guanting reservoir].
The atrazine in water was determined by SPE-LC-MS. It only took 40 min to analysis a sample. The detection limit was 10 ng/L. Atrazine was detected in water of Guanting reservoir. The concentration of atrazine in water samples of Guanting reservoir was 0.67-3.9 micrograms/L. The source of atrazine in water was discussed. A plant situated at upstream of Yanghe River was thought a primary source of atrazine in Guanting reservoir.
Thermal stability of reconstituted collagen fibrils. Shrinkage characteristics upon in vitro maturation
Thermal stability measured as area shrinkage without tension during heating was determined for membranes of collagen fibrils reconstituted from solutions of highly purified rat skin collagens. Shrinkage in per cent of area at 25 degrees C and shrinkage temperature were quantitated in a standardized way and determined as a function of in vitro maturation time for 11 to 104 days after aggregation for the collagen membranes. Similar to reports on intact rat skin, shrinkage temperature remained constant and shrinkage per cent declined with a rate decreasing with time during maturation. Solubility in water at 80 degrees C for 2 hours was 95-96% and remained unchanged for the maturation time (about 2 months) studied. The decreased shrinkage reflecting a lower degree of collapse is ascribed to an increasing thermal stability of the membranes during maturation. Development of heat-stable bonds in the reconstituted collagen fibrils is taken up to be amenable to this increased stability. Similarity in changes of shrinkage characteristics during in vivo and in vitro maturation indicates that maturation changes in reconstituted collagen fibrils reflect those occurring in intact collagen during in vivo aging.