This paper describes the hydrogenation of impurities in the methanol-containing effluent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly spac...This paper describes the hydrogenation of impurities in the methanol-containing effluent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly space velocity(WHSV) and H2/methanol ratio on the concentration of various impurities in methanol solvent were investigated. It was found out that the aldehyde, hydrogen peroxide and nitro compounds in the methanol solvent could be completely hydrogenated over the Ni catalyst under proper reaction conditions. 90% of acetone and up to 50% of acetals(ketals) existing in the methanol solvent could be hydrogenated. No significant change was observed for the rest of the impurities that were present in the methanol solvent(i. e., 1-methoxy-2-propanol, 2-methoxy-1-propanol and 1,2-propanediol). The H2O2 decomposition reaction was enhanced using Ni catalyst, through the formation of NioOH, but no oxygen was found in the off-gas of hydrogenation reaction since NioH could react on NioOH formed via dissociative adsorption of hydrogen peroxide, or on NioO formed via adsorption of oxygen.展开更多
The effect of tumor-targeted photodynamic therapy（PDT） was improved by designing nanotheranostics to promote oxygenation in a tumor microenvironment（TME）wherein hypoxia, acidosis, and the elevated levels of H2O2 a...The effect of tumor-targeted photodynamic therapy（PDT） was improved by designing nanotheranostics to promote oxygenation in a tumor microenvironment（TME）wherein hypoxia, acidosis, and the elevated levels of H2O2 are three main characteristics. In this study, a carbon dot（CD）PDT agent recently developed by our group was firstly applied as reducing agent to react with potassium permanganate for fabricating CDs/manganese dioxide（CDs/MnO2） composites,which were in turn modified with polyethylene glycol（PEG） to form water-soluble CDs/MnO2-PEG nanohybrids. In a normal physiological environment, the as-prepared nanohybrids exhibited quenched fluorescence, weak singlet oxygen generation, and low magnetic resonance imaging（MRI） signal.However, given the high sensitivity of MnO2 to the TME, the CDs/MnO2-PEG nanohybrids changed from an ＂off＂ to an＂on＂ state with synchronously enhanced fluorescence, singlet oxygen generation, and MRI signal in the TME. In vitro and in vivo analyses have revealed that CDs/MnO2-PEG nanohybrids could be applied as TME-driven, turn-on nanotheranostics for the MR/fluorescence bimodal imaging-guided PDT of cancer.Moreover, complete clearance of CDs/MnO2-PEG nanohybrids from the body of mice was observed, indicating their low long-term toxicity and good biocompatibility. This work offers a new nanotheranostic candidate for modulating the unfavorable TME, particularly for the targeted PDT of cancer through precise positioning and oxygen generation.展开更多
This report discloses a series of naphthalimide-based bifunctional fluorescent probes for hydrogen peroxide and diols.As a result,these molecules not only demonstrated high turn-on fluorescent response and good select...This report discloses a series of naphthalimide-based bifunctional fluorescent probes for hydrogen peroxide and diols.As a result,these molecules not only demonstrated high turn-on fluorescent response and good selectivity towards hydrogen peroxide over other relevant reactive oxygen species,but also displayed different responses to diols.Therefore,these fluorescent probes could be served as sensitive,selective and practical chemosensors for both hydrogen peroxide and diols under physiologicallike conditions.展开更多
文摘This paper describes the hydrogenation of impurities in the methanol-containing effluent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly space velocity(WHSV) and H2/methanol ratio on the concentration of various impurities in methanol solvent were investigated. It was found out that the aldehyde, hydrogen peroxide and nitro compounds in the methanol solvent could be completely hydrogenated over the Ni catalyst under proper reaction conditions. 90% of acetone and up to 50% of acetals(ketals) existing in the methanol solvent could be hydrogenated. No significant change was observed for the rest of the impurities that were present in the methanol solvent(i. e., 1-methoxy-2-propanol, 2-methoxy-1-propanol and 1,2-propanediol). The H2O2 decomposition reaction was enhanced using Ni catalyst, through the formation of NioOH, but no oxygen was found in the off-gas of hydrogenation reaction since NioH could react on NioOH formed via dissociative adsorption of hydrogen peroxide, or on NioO formed via adsorption of oxygen.
基金supported by the National Natural Science Foundation of China (51472252 and 51572269)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17000000)
文摘The effect of tumor-targeted photodynamic therapy（PDT） was improved by designing nanotheranostics to promote oxygenation in a tumor microenvironment（TME）wherein hypoxia, acidosis, and the elevated levels of H2O2 are three main characteristics. In this study, a carbon dot（CD）PDT agent recently developed by our group was firstly applied as reducing agent to react with potassium permanganate for fabricating CDs/manganese dioxide（CDs/MnO2） composites,which were in turn modified with polyethylene glycol（PEG） to form water-soluble CDs/MnO2-PEG nanohybrids. In a normal physiological environment, the as-prepared nanohybrids exhibited quenched fluorescence, weak singlet oxygen generation, and low magnetic resonance imaging（MRI） signal.However, given the high sensitivity of MnO2 to the TME, the CDs/MnO2-PEG nanohybrids changed from an ＂off＂ to an＂on＂ state with synchronously enhanced fluorescence, singlet oxygen generation, and MRI signal in the TME. In vitro and in vivo analyses have revealed that CDs/MnO2-PEG nanohybrids could be applied as TME-driven, turn-on nanotheranostics for the MR/fluorescence bimodal imaging-guided PDT of cancer.Moreover, complete clearance of CDs/MnO2-PEG nanohybrids from the body of mice was observed, indicating their low long-term toxicity and good biocompatibility. This work offers a new nanotheranostic candidate for modulating the unfavorable TME, particularly for the targeted PDT of cancer through precise positioning and oxygen generation.
基金supported by the Shandong Natural Science Foundation(JQ201019)the Independent Innovation Foundation of Shandong University,IIFSDU(2010JQ005)
文摘This report discloses a series of naphthalimide-based bifunctional fluorescent probes for hydrogen peroxide and diols.As a result,these molecules not only demonstrated high turn-on fluorescent response and good selectivity towards hydrogen peroxide over other relevant reactive oxygen species,but also displayed different responses to diols.Therefore,these fluorescent probes could be served as sensitive,selective and practical chemosensors for both hydrogen peroxide and diols under physiologicallike conditions.
