Objective To com pare and explore the application value of diatom nitric acid digestion method and plankton 16S rDNA PCR method for drow ning identification. Methods Forty drow ning cases from 2010 to 2011 were collected from Department of Forensic Medicine of Wenzhou Medical University. Sam ples including lung, kidney, liver and field water fromeach case were tested with diatom nitric acid digestion method and plankton 16S rDNAPCR method, respectively. The Diatom nitric acid digestion method and plankton 16S rDNAPCR method required 20 gand 2g of each organ,and 15 mL and 1.5 mL of field water, respectively. The inspection time and detection rate were com pared between the two methods. Results Diatom nitric acid digestion method m ainly detected two species of diatom s, Centriae and Pennatae, while plankton 16S rDNA PCR method am plified a length of 162 bp band. The average inspection time of each case of the Diatom nitric acid digestion method was (95.30±2.78) min less than (325.33±14.18)min of plankton 16S rDNA PCR method (P<0.05).The detection rates of two methods for field water and lung were both 100% . For liver and kidney, the detection rate of plankton 16S rDNA PCR method was both 80% , higher than 40% and 30% of diatom nitric acid digestion method (P<0.05), respectively. Conclusion The laboratory testing method needs to be appropriately selected according to the specific circum stances in the forensic appraisal of drow ning. Com pared with diatom nitric acid digestion method, plankton 16S rDNA PCR method has practice values with such advantages as less quantity of sam ples, huge inform ation and high specificity.

In order to promote the growth of chondrocyte ATDC-5 in collagen type II-hyaluronic acid-chondroitin sulfate composite scaffolds constructed previously in vitro, the sustained-releasing chitosan microspheres loading TGF-β1 were prepared by emulsification and cross-linking. In addition, ATDC-5 was inoculated into the scaffolds incorporating the chitosan microspheres with TGF-β1. Results show that the morphology of microsphere was round and uniform, mean diameter was about 100 nm, absorption rate was up to 983.7%±4.38%.When the microsphere was incubated under the condition of 10⁷ U/L lysozyme, the degradation rate was only 51.0%±1.8% on day 28. Moreover, to compare the effect of TGF-β1, the growth of ATDC-5 in different scaffolds was observed by MTT assay and fluorescence staining test. According to the cumulative release curve, TGF-β1 was released quickly at initial 24 h, then gradually decelerated, finally reached the plateau after 120 h. MTT assay and fluorescence staining test demonstrated that the scaffolds were suitable for ATDC-5 growth and proliferation, as well as, suggested that the sustained-releasing chitosan microspheres loading TGF-β1 could significantly promote the growth of ATDC-5.