Preparation of N₂/CO₂ Triggered Reversibly Coagulatable and Redispersible Latexes by Emulsion Polymerization of Styrene with a Reactive Switchable Surfactant

This work reports the development of a reversibly coagulatable and redispersible polystyrene latex system that can be triggered by N₂/CO₂. The coagulatability and redispersibility of the latexes were achieved by employing 0.9–5.6 wt % (<i>N</i>-amidino)­dodecyl acrylamide (<b>DAm</b>), a reactive switchable surfactant, in an emulsion polymerization of styrene under CO₂ atmosphere. The resulted latex particles were readily coagulated by N₂ bubbling at 60 °C and redispersed by CO₂ bubbling and ultrasonication, which switched amidine moieties between neutral and ionic states. The coagulation/redispersion processes were repeatable. The prepared latexes showed good stabilities against electrolytes, especially with higher charges

Data_Sheet_1_Postmortem submersion interval estimation of cadavers recovered from freshwater based on gut microbial community succession.docx

Microbial community succession during decomposition has been proven to be a useful tool for postmortem interval (PMI) estimation. Numerous studies have shown that the intestinal microbial community presented chronological changes after death and was stable in terrestrial corpses with different causes of death. However, the postmortem pattern of intestinal microbial community succession in cadavers retrieved from water remains unclear. For immersed corpses, the postmortem submersion interval (PMSI) is a useful indicator of PMI. To provide reliable estimates of PMSI in forensic investigations, we investigated the gut microbial community succession of corpses submersed in freshwater and explored its potential application in forensic investigation. In this study, the intestinal microbial community of mouse submersed in freshwater that died of drowning or CO2 asphyxia (i.e., postmortem submersion) were characterized by 16S rDNA amplification and high-throughput sequencing, followed by bioinformatic analyses. The results demonstrated that the chronological changes in intestinal bacterial communities were not different between the drowning and postmortem submersion groups. α-diversity decreased significantly within 14 days of decomposition in both groups, and the β-diversity bacterial community structure ordinated chronologically, inferring the functional pathway and phenotype. To estimate PMSI, a regression model was established by random forest (RF) algorithm based on the succession of postmortem microbiota. Furthermore, 15 genera, including Proteus, Enterococcus, and others, were selected as candidate biomarkers to set up a concise predicted model, which provided a prediction of PMSI [MAE (± SE) = 0.818 (± 0.165) d]. Overall, our present study provides evidence that intestinal microbial community succession would be a valuable marker to estimate the PMSI of corpses submerged in an aquatic habitat.</p