Protein profile of circulating extracellular vesicles reveals biomarker candidates for diagnosis of post-traumatic deep vein thrombosis.

BACKGROUND AND OBJECTIVE: Deep vein thrombosis (DVT) is a common complication after trauma and mostly without specific symptoms. Timely diagnosis and early appropriate treatment measures can prevent further development of thrombosis for patients with traumatic lower extremity fractures. Although extracellular vesicles (EVs) are confirmed as promising disease biomarkers, little is known about the role of altered levels and composition in the diagnosis of post-traumatic DVT. METHOD: The levels of circulating EVs subgroups were measured using flow cytometry. Isolated EVs were characterized and subjected to proteomics analysis to screen for differentially expressed proteins (DEPs) between DVT and non-DVT patients. Regularized logistic regression analysis based on L2 penalty terms using R's caret package was applied to build a model for DVT diagnosis. RESULTS: Compared to non-DVT patients, DVT patients had higher circulating hepatocyte-derived EVs (hEVs) with good predictive value for post-traumatic DVT diagnosis. The results of the proteomic analysis showed that differentially expressed proteins (DEPs) of circulating EVs between the DVT group and non-DVT group were enriched in the complement and coagulation cascade. Finally, an integrated model of five biomarkers including SERPING1, C8G, CFH, FIX, and hEVs level was established for post-traumatic DVT diagnosis with robust identification of the traumatic patients with and without DVT (AUC 0.972). CONCLUSION: Post-traumatic DVT patients had changed levels and composition of circulating EVs compared to non-DVT patients and healthy controls. Circulating EVs may acquire pathological protein signatures and become potential biomarkers for identifying subjects' post-traumatic DVT.

Multiple environmental risk assessments of heavy metals and optimization of sludge dewatering: Red mud-reed straw biochar combined with Fe2+ activated H2O2.

In this study, Fe-rich biochar (RMRS-BC) was prepared from red mud and reed straw to improve sludge dewatering and transformation of heavy metals (HMs, including Cd, Cr, Cu, Pb, and Zn). The optimal concentrations of RMRS-BC, Fe2+, and H2O2 to promote sludge dewaterability were identified by response surface methodology (RSM). The optimal dosages of RMRS-BC, Fe2+, and H2O2 were 74.0, 104.9, and 75.7 mg/g dry solids (DS), respectively. The corresponding capillary suction time (CST) and water content of sludge cake were 14.3 s and 51.25 wt%. For the improvement mechanism, heterogeneous and homogeneous Fenton reactions occurred due to RMRS-BC and Fe2+ activating H2O2. The extracellular polymeric substances (EPS) decomposed into dissolved organic matter (proteins and polysaccharides), thereby promoting the transformation of bound water to free water and further reducing the water content of the sludge cake. The research quantitatively assessed the environmental risk of heavy metals in the conditioned sludge cake based on bioavailability and ecotoxicity, pollution levels and potential ecological risks. Compound conditioning using RMRS-BC, Fe2+, and H2O2 could significantly improve the solubility and reduce the leaching toxicity of HMs. In general, RMRS-BC combined with Fe2+ to activate H2O2 provided an effective method to enhance sludge dewaterability and reduce HMs risk.

Enhanced sludge dewaterability by Fe-rich biochar activating hydrogen peroxide: Co-hydrothermal red mud and reed straw.

This study proposed Fe-rich biochar (RMRS-BC) produced by the co-hydrothermal treatment of red mud and reed straw, industrial waste and agricultural waste, as a novel sludge conditioner. It had been proven that heterogeneous and homogeneous Fenton reactions occurred during the sludge conditioning process, in which RMRS-BC activated H2O2 to improve sludge dewaterability. Results demonstrated that the optimal condition was 7.5 wt% dry solids (DS) of RMRS-BC at a mass ratio of 1:1 combined with H2O2. The corresponding water content of sludge cakes and the capillary suction time reduction efficiency were 57.88 wt% and 69.76%, respectively. The Fe3O4 supported in the RMRS-BC structure was used as a catalyst to produce heterogeneous reaction, and the Fe2+ leached from the RMRS-BC after acidification happened homogeneous reaction. Double Fenton reaction in sludge conditioning enhanced the production efficiency of ·OH, the sludge flocs were dispersed into smaller particles, more bound water from the extracellular polymeric substances (EPS) was released, and sludge dewaterability performance was improved. Another main mechanism for enhancing dewaterability was to use RMRS-BC as a skeleton builder to reduce the compressibility of sludge cakes and facilitated free water to flow out. In summary, the Fenton oxidation method activated by RMRS-BC is feasible in improving sludge dewatering.