The Experts below are selected from a list of 8478 Experts worldwide ranked by ideXlab platform
Chiing-chang Chen - One of the best experts on this subject based on the ideXlab platform.
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chemical oxidative degradation of acridine orange dye in aqueous solution by fenton s reagent
Journal of The Chinese Chemical Society, 2009Co-Authors: Chiing-chang Chen, Yiyou TzengAbstract:Degradation of acridine orange (AO) in aqueous solution by Fenton's reagent (Fe2+ and H2O2) was investigated. The effects of different reaction parameters such as initial AO concentration, pH value of solution, ferrous concentration, hydrogen peroxide concentration, and the presence of chloride ion on the oxidative degradation of AO were investigated. Under optimum conditions, 2 mM H2O2, 0.4 mM Fe2+ and pH 3.0, the initial 0.2 mM AO solution was reduced by 95.8% within 10 min. The primary intermediates of the degradation reaction of AO were identified. The analytical results indicated that the N-de-methylation degradation of AO dye took place in a Stepwise Manner to yield mono-, di-, tri-, and tetra-N-de-methylated AO species generated during the Fenton process. The probable degradation pathways were proposed and discussed.
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titanium dioxide mediated photocatalytic degradation of acridine orange in aqueous suspensions under uv irradiation
Dyes and Pigments, 2008Co-Authors: Fu Der Mai, Chiing-chang ChenAbstract:Abstract The TiO 2 /UV photocatalytic degradation of Acridine Orange (AO) was investigated in aqueous heterogeneous suspension. The results indicated that photocatalytic reactions were enhanced in alkaline medium. While the rate of photocatalytic degradation of the dye increased with increasing concentration of TiO 2 , at high doses of TiO 2 , the rate of reaction was reduced as a result of light attenuation. To obtain a better understanding of the mechanistic details of this TiO 2 assisted dye photodegradation, the intermediates of the processes were separated, identified, and characterized using HPLC–ESI-MS. It was found that N -de-methylation degradation of the dye took place in a Stepwise Manner to yield mono-, di-, tri-, and tetra- N -de-methylated species. The probable photodegradation pathways are proposed and discussed.
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mechanistic studies of the photocatalytic degradation of methyl green an investigation of products of the decomposition processes
Environmental Science & Technology, 2007Co-Authors: Chiing-chang ChenAbstract:The methyl green (MG) dye dissolves into an alkaline solution when the pH value is too high (pH 9). The cationic MG dye molecules are converted into the colorless carbinol base (CB) and produce crystal violet (CV) dye and ethanol by hydroxide anion. Thirty-three intermediates of the process were separated, identified, and characterized by HPLC-ESI-MS technique in this study and their evolution during the photocatalytic reaction is presented. Moreover, the other intermediates formed in the photocatalytic degradation MG processes were separated and identified by HPLC-PDA technique. The results indicated that the N-de-methylated degradation of CV dye took place in a Stepwise Manner to yield N-de-methylated CV species, and the N-de-alkylated degradation of CB also took place in a Stepwise Manner to yield N-de-alkylated CB species generated during the processes. Moreover, the oxidative degradation of the CV dye (or CB) occurs to yield 4-(N,N-dimethylamino)phenol (DAP), 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino)benzophenone (DDBP) and their N-de-methylated products [or to yield 4-(N-ethyl-N,N-dimethyl)aminophenol (EDAP), DDBP, 4-(N-ethyl-N,N-dimethylamino)-4'-(N',N'-dimethylamino)benzophenone (EDDBP), DAP, and their N-de-alkylated products], which were found for the first time. A proposed degradation pathway of CV and CB is presented, involving mainly the N-de-alkylation and oxidation reaction.
Fu Der Mai - One of the best experts on this subject based on the ideXlab platform.
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titanium dioxide mediated photocatalytic degradation of acridine orange in aqueous suspensions under uv irradiation
Dyes and Pigments, 2008Co-Authors: Fu Der Mai, Chiing-chang ChenAbstract:Abstract The TiO 2 /UV photocatalytic degradation of Acridine Orange (AO) was investigated in aqueous heterogeneous suspension. The results indicated that photocatalytic reactions were enhanced in alkaline medium. While the rate of photocatalytic degradation of the dye increased with increasing concentration of TiO 2 , at high doses of TiO 2 , the rate of reaction was reduced as a result of light attenuation. To obtain a better understanding of the mechanistic details of this TiO 2 assisted dye photodegradation, the intermediates of the processes were separated, identified, and characterized using HPLC–ESI-MS. It was found that N -de-methylation degradation of the dye took place in a Stepwise Manner to yield mono-, di-, tri-, and tetra- N -de-methylated species. The probable photodegradation pathways are proposed and discussed.
Cengiz V Ozalp - One of the best experts on this subject based on the ideXlab platform.
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staphylococcus aureus detection in blood samples by silica nanoparticle oligonucleotides conjugates
Biosensors and Bioelectronics, 2016Co-Authors: Baris Ata Borsa, Bilge Guvenc Tuna, Frank J Hernandez, Luiza I Hernandez, Gulay Bayramoglu, Yakup M Arica, Cengiz V OzalpAbstract:A fast, specific and sensitive homogeneous assay for Staphylococcus aureus detection was developed by measuring the activity of secreted nuclease from the bacteria via a modified DNA oligonucleotide. As biosensor format, an effective system, Nanokeepers as previously reported, were used for triggered release of confined fluorophores, and hence specific detection of S. aureus on nuclease activity was obtained. The interference from blood components for fluorescent quantification was eliminated by a pre-purification by aptamer-functionalized silica magnetic nanoparticles. The reported assay system was exclusively formed by nucleic acid oligos and magnetic or mesoporous silica nanoparticles, that can be used on blood samples in a Stepwise Manner. The assay was successfully used as a sensing platform for the specific detection of S. aureus cells as low as 682 CFU in whole blood.
Jing Chen - One of the best experts on this subject based on the ideXlab platform.
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photochemical decomposition of perfluorooctanoic acid in aqueous periodate with vuv and uv light irradiation
Journal of Hazardous Materials, 2010Co-Authors: Menghua Cao, Bin Wang, Linling Wang, Songhu Yuan, Jing ChenAbstract:Abstract The photochemical decomposition of perfluorooctanoic acid (PFOA) in aqueous periodate (IO 4 − ) was investigated under two types of low-pressure mercury lamps: one emits at 254 nm light (UV light) and the other emits both 254 nm and 185 nm light (VUV light). PFOA decomposed efficiently under VUV light irradiation while it decomposed poorly under UV light irradiation. The addition of IO 4 − significantly increased the rate of decomposition and defluorination of PFOA irradiated with UV light whereas it decreased both processes under VUV irradiation. Reactive radical (IO 3 ) generated by photolysis of IO 4 − initiated the oxidation of PFOA in UV process. Aquated electrons ( e aq − ), generated from water homolysis, scavenged IO 4 − resulting in decrease of reactive radical species production and PFOA decomposition. The shorter-chain perfluorocarboxylic acids (PFCAs) formed in a Stepwise Manner from long-chain PFCAs.
Myunggon Ko - One of the best experts on this subject based on the ideXlab platform.
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tet family dioxygenases and dna demethylation in stem cells and cancers
Experimental and Molecular Medicine, 2017Co-Authors: Jungeun An, Myunggon KoAbstract:Proteins that remove chemical tags from DNA play key regulatory roles in cell development and the initiation of cancer. In a review article, Myunggon Ko from the Ulsan National Institute of Science and Technology in South Korea and colleagues describe how enzymes of the Ten-eleven translocation (TET) family reverse the methylation of cytosine in DNA, affecting cellular differentiation, embryonic development and cancer. The researchers detail the mechanisms by which TET proteins remove methyl groups from cytosine residues in a Stepwise Manner. The absence of functional TET has been implicated in a wide range of human cancers, in particular, cancers of the blood cells. In mouse models, reintroducing TET activity into blood stem cells helped prevent leukemia, suggesting that restoring TET function in people could have therapeutic benefit for cancer patients.
