Jiaojiao Li,Jihua Wang,Jianye Li,Xin Yang,Jiangling Wan,Chuansheng Zheng,Qing Du,Guofeng Zhou,Xiangliang Yang
Magnetic resonance imaging (MRI) has attracted increasing attention as a feasible alternative or adjunctive imaging modality for X-ray digital subtraction angiography because of the high tissue resolution and non-ionization radiation. In this study, a one-step electrospray method was developed to fabricate PVA microspheres encapsulated with in situ synthesized Fe 3 O 4 nanoparticles . Fe 3 O 4 @PVA microspheres were mono-dispersed black spheres with a wide range of sizes (262–958 µm). The in situ -synthesized Fe 3 O 4 nanoparticles were used as the contrast agent of MRI and the cross-linkers of PVA matrixes for the embolization purpose. In vivo evaluation of renal arteries of normal rabbits showed that Fe 3 O 4 @PVA microspheres had good embolic effect and enhanced capability of MRI. In vitro and in vivo biosafety assessment confirmed that Fe 3 O 4 @PVA microspheres had favorable biocompatibility. The DOX-loaded Fe 3 O 4 @PVA microspheres showed a typical drug-sustained release profile. These results suggest that the prepared DOX-loaded Fe 3 O 4 @PVA microspheres have the function of MRI, embolotherapy and chemotherapy. We expect our study could provide a simple and useful approach for the systematic design , fabrication, and application of a new type of magnetic microspheres as a triple-functional embolic agent for the development of MRI-guided TACE. Statement of significance Due to the low tissue resolution and hazardous ionization radiation of X-ray digital subtraction angiography, it is beneficial to study MR imaging embolic microspheres for the development of MRI-guided TACE. In this study, a one-step electrospray method was firstly developed to fabricate PVA microspheres encapsulated with in situ synthesized Fe 3 O 4 nanoparticles. Then, chemotherapeutic agent (DOX), contrast media of MRI (Fe 3 O 4 ) and embolic agent (PVA matrix) were combined together in one body (DOX-loaded Fe 3 O 4 @PVA microspheres) to achieve the triple effects of chemotherapy, MR imaging and embolization. This triple-functional embolic agent offers potential for the future development of MRI-guided TACE.
Disinfection is a key step in drinking water treatment process to prevent water-borne infections. However, reactions between chlorine, one of the most common disinfectants, and natural organic matter (NOM) often lead to the formation of hazardous disinfection byproducts (DBPs). However, the cytotoxicity of some DBPs is still poorly understood. Such knowledge is critical for proper selection of disinfection processes. We investigated the effects of DBPs on mouse acute liver injury. The exacerbation of liver damage increased with the DBPs concentrations, likely due to the increased hepatic macrophages. Haloacetonitriles (HANs) and haloketones (HKs) are more toxic to Human Hepatocellular (Hep3B) cells than trihalomethanes (THMs). Cytotoxicity of DBPs were governed by the halogen type (brominated DBPs > chlorinated DBPs) and the numbers of halogen atoms per molecule. Then, we used the pilot-scale WDS to study the best conditions for reducing the formation of DBPs. The result showed that the formation of DBPs followed the order: stainless-steel (SS) > ductile iron (DI) > polyethylene (PE) pipe. Higher flowrate promoted the formation of DBPs in all three pipes. The results suggest that the formation of DBPs in chlorine disinfection can be reduced by using PE pipes and low flow rate in water distribution systems (WDS).
Pre-ozonation is widely used in the treatment of algae-containing water. Recent studies suggest that pre-ozonation could enhance the formation of haloacetaldehydes (HALs) but the mechanisms have not been clearly clarified. The study assessed the formation of dichloroacetaldehyde (DCAL) and trichloroacetaldehyde (TCAL) from model algal organic matters (Gly-Ala and Leu-Ala), and clarified the transformation mechanisms from the insight of quantum chemical computations. Results demonstrated a significant increase in HALs formation potential after pre-ozonation. When the dosage of O 3 was 0.5 mg L −1 , the formation of DCAL and TCAL increased 100 % and 113 % after chlorination, respectively. The initial pH of pre-ozonation was observed to be an important factor that influenced the HALs formation potential. The alkaline conditions promoted the formation of HALs, while acidic conditions have an inhibitory effect. Furthermore, the ultra-performance liquid chromatography high-resolution mass spectrometry (UPLC-HRMS) was applied to identify the transformation products of the pre-ozonation-chlorination process. Combined with quantum chemical computations, the transformation pathways of HALs were proposed. It was found that pre-ozonation promotes the formation of acetaldehyde, an intermediate during the formation of HALs. The initial pH plays an important role in the production of HALs, which influenced the reaction pathways and affected OH• formation. This study provides an in-depth analysis of the reaction mechanism and offers new theoretical insights for mitigating, controlling, and managing the risks associated with HALs.
危险品化学品经营许可证（带存储）