Degradation of a non-oxidizing biocide in circulating cooling water using UV/persulfate: Kinetics, pathways, and cytotoxicity.

In industry, isothiazolinone (a mixture containing 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2-methyl-4-isothiazolin-3-one (MIT), CMIT-MIT) as a non-oxidizing biocide is extensively used to control the growth of microorganisms in the circulating cooling water system, which potentially threatens the ecological environment and human health. In this work, the oxidative degradation of CMIT-MIT by UV/persulfate (PS) technology on a laboratory-scale was systematically investigated. The degradation of CMIT-MIT was greatly improved by UV/PS compared with only UV or oxidant. During the photolysis of 60 mg/L PS, the degradation rate and TOC mineralization rate of CMIT-MIT were 91% and 34.7%, respectively. The contributions of .OH and SO4·- to CMIT-MIT degradation in the UV/PS system were estimated to be 0.93% and 32.12% respectively. The degradation rate of CMIT-MIT decreased slightly with the increase of pH. The presence of SO42- and NO3- had no significant effect on the degradation of CMIT-MIT, while the presence of Cl- and CO32- inhibited the CMIT-MIT removal rate. The degradation pathways and three possible intermediates of CMIT-MIT were obtained. After degradation of CMIT-MIT by UV/PS process, the cytotoxicity decreased within 20 min, effectively indicating that UV/PS could be as a potential technology to remove the CMIT-MIT in water treatment.

A Pyrene Fluorescent Probe for Rapid Detection of Ferric Ions.

The 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt (PTSA) is a pyrene derivative with high fluorescence characteristics and is widely used in fluorescence tracer. This study aims at investigating a simple and fast fluorescence detection method for determining the concentration of ferric ion by using PTSA, which the principle is that the fluorescence quenching of PTSA by ferric ions. Theoretical and experimental methods were adopted to deeply analyze its detection performance and characteristics. The fluorescence quenching phenomena under different pH conditions and the effect of the different interfering metal ions on PTSA/Fe3+ system was studied. The results showed that the PTSA was quite promising for the fluorescence detection of trace ferric ions, and the limit of detection is 9 µg/L. This study is envisioned to provide inspirational insights on trace detection of iron ions, opening new routes for water monitoring use fluorescence properties.

Degradation of fluorescent dye-Solvent Green 7 (HPTS) in wastewater by advanced oxidation process.

Solvent Green 7 (HPTS) is a widely used fluorescent dye. As a kind of polycyclic aromatic hydrocarbon (PAHs) derivative, HPTS would cause pollution when it is discharged into the environment. This study adopted advanced oxidation processes (UV/H2O2) to degrade the HPTS in aqueous solution and investigated the effects of various factors on the degradation. The results showed that: the initial concentration and the fluorescence characteristics of HPTS reduced the degradation efficiency. When the oxidant concentration of H2O2 was 3 mg/L, the degradation efficiency and cost of HPTS (20 mg/L) were the most appropriate; when there were various inorganic anions in the solution, the degradations were not affected, but when the solution was strong acid and there existed a lot of chloride ions, the degradation of HPTS was inhibited. The degradation pathways indicated HPTS degraded into naphthalene derivatives, benzene derivatives through oxidation and decarboxylation reactions, finally into water and carbon dioxide. Further research for substances similar to HPTS structure will make progress in understanding the degradation process of PAHs.

Eicosapentaenoic acid's metabolism of 15-LOX-1 promotes the expression of miR-101 thus inhibits Cox2 pathway in colon cancer.

PURPOSE: It is well known that diet Eicosapentaenoic acid (EPA) is beneficial to colon cancer (CC). However,  the underlying molecular mechanisms of EPA-relating miRNAs on genesis and development of this area is still unclear. MATERIALS AND METHODS: This study tries to find the function and specific role of EPA in CC through quantitative PCR (qPCR), Western blotting, immunofluorescence (IF), mass spectrometry, and immunohistochemistry (IHC) assays. By these methods, the enrichment of 15-LOX-1 metabolites of EPA, the expression of miR-101 and Cox2, and the relationship among them in CC are measured. RESULTS: The quantity of miR-101 was obviously suppressed in CC tissues and SW480 cells. After application of miR-101 mimics in CC cell lines, the Cox2 expression was inhibited too. Next, we confirmed that EPA could increase the expression of miR-101 induced by 15-LOX-1. Finally, we tested whether EPA functions as a regulator of miR-101 via the production of resolvin E3. CONCLUSION: Our data demonstrate that the EPA-15-LOX-1-miR-101-Cox2 signaling pathway owns a crucial position in the pathogenesis and development of diet-related CC. These findings exert exciting meanings for presenting new therapeutic angles in CC.