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130 results on '"Lu, Xianghong"'

19. Solvent-free oxidative cleavage of epoxy fatty acid methyl esters by a 'release and capture' catalytic system

Author

Meizhen Lu, Lu Xianghong, Hailun Jin, Jianbing Ji, Ni Yang, Libo Peng, Yong Nie, Qinglong Xie, Xuejun Liu, and Zhenyu Wu

Subjects
chemistry.chemical_classification, 010405 organic chemistry, Fatty acid, chemistry.chemical_element, Epoxy, Tungsten, 010402 general chemistry, 01 natural sciences, Pollution, Aldehyde, 0104 chemical sciences, Catalysis, Adsorption, chemistry, visual_art, visual_art.visual_art_medium, Environmental Chemistry, Leaching (metallurgy), Mesoporous material, Nuclear chemistry
Abstract

The creation of a catalytic method that possesses high activity and effective reusability for the oxidative cleavage of vegetable oils and their derivatives to prepare bio-based oxo-chemicals is a challenge. This work introduces a “release and capture” catalytic system consisting of H2O2, WO3 and mesoporous SnO2. This system was intended to promote catalyst reusability in the oxidative cleavage of methyl 9,10-epoxystearate (ME) to the corresponding aldehydes. No organic solvent was used in the reaction. The reaction temperature, molar ratio of ME/WO3/H2O2, and reaction time were optimized to 70 °C, 1/0.017/1.3, and 20 min, respectively. Under these conditions, complete ME conversion and 80% aldehyde yield were obtained. The hot filtration experiment and ICP-MS analysis confirmed the leaching of tungsten. Mesoporous SnO2 did not affect the ME conversion and aldehyde yield, but effectively adsorbed the leached tungsten. The catalyst in this system showed no significant decrease in activity after being reused ten times.

Published
2019

30. Oxidative Cleavage of Methyl 9,10‐Epoxystearate over WO 3 /MCM‐41 for Methyl 9‐Oxononanoate Production

Author

Meizhen Lu, Jianbing Ji, Libo Peng, Lu Xianghong, Xuejun Liu, Yong Nie, and Qinglong Xie

Subjects
010405 organic chemistry, Chemistry, Nonanal, General Chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Industrial and Manufacturing Engineering, 0104 chemical sciences, chemistry.chemical_compound, MCM-41, Oxidative cleavage, Food Science, Biotechnology
Published
2018

34. Oxidative Cleavage of Methyl 9,10‐Epoxystearate over WO3/MCM‐41 for Methyl 9‐Oxononanoate Production.

Author

Lu, Meizhen, Peng, Libo, Xie, Qinglong, Nie, Yong, Liu, Xuejun, Lu, Xianghong, and Ji, Jianbing

Subjects
STEARATES, TUNGSTEN oxides, CHEMICAL synthesis, FEEDSTOCK, TEMPERATURE effect, EPOXY compounds
Abstract

At present, the utilization of grease has attracted more and more attention. This article presents a simple method that efficiently cleaves methyl oleate‐derived methyl 9,10‐epoxystearate (a) to give high yields of methyl 9‐oxononanoate (d) with nonanal (c) as co‐product. A WO3/MCM‐41 catalyst is prepared via direct mixed‐gel synthesis. The catalyst is tested in the oxidative cleavage of a to produce d which can be used as a polymer precursor or an important feedstock. The effects of WO3 loading, temperature, time, H2O2/a molar ratio, catalyst/a weight ratio, and t‐BuOH/a weight ratio on the a conversion and d yield are examined using single‐factor experiments. The optimal reaction conditions are determined by orthogonal experiments. The optimal WO3 loading, temperature, time, H2O2/a molar ratio, catalyst/a weight ratio, and t‐BuOH/a weight ratio are 35%, 80 °C, 20 min, 1.3, 0.04, and 0.5, respectively. Under these conditions, the a conversion and d yield reach 99.4 and 78.4%, respectively. In addition, the catalyst shows no significant decrease in activity after being reused three times. Moreover, the reaction mechanism is studied based on the product distribution over time. Practical Applications: Few studies on methyl 9,10‐epoxystearate used as the raw material to give methyl 9‐oxononanoate and nonanal are found. Because the ethylene oxide bond is more unstable than the carbon–carbon double bond, the oxidative cleavage of methyl 9,10‐epoxystearate is easier than cleavage of methyl oleate that allows the oxidative cleavage to be done under milder conditions. Methyl 9‐oxononanoate can be converted to a monomer of high‐value polymers and is also an important feedstock in the production of chemicals. The co‐product nonanal is a natural spice which can be used in the fragrance industry. The results show that the reaction time is short and methyl 9‐oxononanoate yield is high under mild reaction conditions. The method in this study can also be widely used in other oxidative cleavage reactions of epoxides. Methyl 9,10‐epoxystearate is used as the raw material to produce methyl 9‐oxononanoate with nonanal as co‐product using WO3/MCM‐41 as catalyst and H2O2 as oxidant. [ABSTRACT FROM AUTHOR]

Published
2018
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37. bFGF Promotes the Migration of Human Dermal Fibroblasts under Diabetic Conditions through Reactive Oxygen Species Production via the PI3K/Akt-Rac1- JNK Pathways

Author

Shi, Hongxue, primary, Cheng, Yi, additional, Ye, Jingjing, additional, Cai, Pingtao, additional, Zhang, Jinjing, additional, Li, Rui, additional, Yang, Ying, additional, Wang, Zhouguang, additional, Zhang, Hongyu, additional, Lin, Cai, additional, Lu, Xianghong, additional, Jiang, Liping, additional, Hu, Aiping, additional, Zhu, Xinbo, additional, Zeng, Qiqiang, additional, Fu, Xiaobing, additional, Li, Xiaokun, additional, and Xiao, Jian, additional

Published
2015
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38. A time interval measurement system based on FPGA used for frequency calibration

Author

Lu Xianghong, Qiu Kailin, He Zhanxiang, and Chen Rujun

Subjects
Engineering, business.industry, Real-time computing, Calibration, Global Positioning System, Frequency standard, business, Field-programmable gate array, Stability (probability), PicoBlaze, Interpolation, Time–frequency analysis
Abstract

The performance of GPS based frequency standard depends on the accuracy and stability of the time interval measurement. Based on the XILINX Spartan-3 FPGA, this paper mainly describes a time interval measurement system which is controlled by the PicoBlaze soft core embedded processor and is suitable for the frequency calibration of GPS based frequency standard. Besides receiving the measurement data and the time information of GPS module, PicoBlaze is used to supervise the system status, which ensures the whole system work effectually. The system has been implemented using XC3S200 device and the test show that the whole system works perfectly and meets the requirement of GPS based frequency standard.

Published
2010

39. bFGF attenuates endoplasmic reticulum stress and mitochondrial injury on myocardial ischaemia/reperfusion via activation of PI 3K/Akt/ ERK 1/2 pathway

Author

Wang, Zhouguang, primary, Wang, Yue, additional, Ye, Junming, additional, Lu, Xianghong, additional, Cheng, Yi, additional, Xiang, Lijun, additional, Chen, Li, additional, Feng, Wenke, additional, Shi, Hongxue, additional, Yu, Xichong, additional, Lin, Li, additional, Zhang, Hongyu, additional, Xiao, Jian, additional, and Li, Xiaokun, additional

Published
2014
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50. bFGF attenuates endoplasmic reticulum stress and mitochondrial injury on myocardial ischaemia/reperfusion via activation of PI3K/Akt/ ERK1/2 pathway.

Author

Wang, Zhouguang, Wang, Yue, Ye, Junming, Lu, Xianghong, Cheng, Yi, Xiang, Lijun, Chen, Li, Feng, Wenke, Shi, Hongxue, Yu, Xichong, Lin, Li, Zhang, Hongyu, Xiao, Jian, and Li, Xiaokun

Subjects
FIBROBLAST growth factor 2, MITOCHONDRIAL pathology, CORONARY disease, MYOCARDIAL reperfusion, PHOSPHOINOSITIDE-dependent kinase-1, PROTEIN kinases, EXTRACELLULAR signal-regulated kinases
Abstract

Extensive research focused on finding effective strategies to prevent or improve recovery from myocardial ischaemia/reperfusion (I/R) injury. Basic fibroblast growth factor (b FGF) has been shown to have therapeutic potential in some heart disorders, including ischaemic injury. In this study, we demonstrate that b FGF administration can inhibit the endoplasmic reticulum ( ER) stress and mitochondrial dysfunction induced in the heart in a mouse model of I/R injury. In vitro, b FGF exerts a protective effect by inhibiting the ER stress response and mitochondrial dysfunction proteins that are induced by tert-Butyl hydroperoxide ( TBHP) treatment. Both of these in vivo and in vitro effects are related to the activation of two downstream signalling pathways, PI3K/Akt and ERK1/2. Inhibition of these PI3K/Akt and ERK1/2 pathways by specific inhibitors, LY294002 and PD98059, partially reduces the protective effect of b FGF. Taken together, our results indicate that the cardioprotective role of b FGF involves the suppression of ER stress and mitochondrial dysfunction in ischaemic oxidative damage models and oxidative stress-induced H9C2 cell injury; furthermore, these effects underlie the activation of the PI3K/Akt and ERK1/2 signalling pathways. [ABSTRACT FROM AUTHOR]

Published
2015
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