Kinetics and optimization of L-tryptophan separation with ion-exchange chromatography

Wei Luo,Limei Fan,Peilian Wei,Hao Chen,Limei Fang,Jin Huang,Zhinan Xu,Peilin Cen 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.5

Adsorption and desorption of L-tryptophan (L-trp) on strong acid cation exchange resin were investigated in a fixed-bed column. L-trp was effectively adsorbed onto the resin HZ-001, with the loading capacity and breakthrough time determined. Four kinetic models, including Adams-Bohard, Wolborska, Thomas, and Yoon-Nelson models,were adopted to determine the kinetic parameters of adsorption and to predict the breakthrough curves. The results showed that the models used described the breakthrough well. Desorption of L-trp from the column bed was performed using aqueous ammonia as the eluant. Optimum procedure was obtained with 2.0M aqueous ammonia at the elution velocity of 6 BV/h. Five cycles of adsorption-elution-regeneration were conducted to evaluate the column reutilization.

Study on Corrosion Law of Large Crude Oil Storage Tank Floor and Risk-Based Inspection and Maintenance Technology

( Fang-wei Luo ),( Ran Ran ),( Lei Wang ) 한국부식방식학회(구 한국부식학회) 2020 Corrosion Science and Technology Vol.19 No.2

In this paper, the author's team has carried out a comparative experimental study on the corrosion characteristics of Q235 steel commonly used in large-scale storage tanks under the specific bottom water environment found with Russian and Daqing crude oil. It was found that there is a certain degree of uniform or local corrosion on the tank floor depending on the kind of bottom water. The bottom water corrosion of Daqing crude oil is a uniform corrosion caused by carbon dioxide. While the Russian crude oil bottom water corrosion is clearly local corrosion caused by co-corrosion of carbon dioxide and hydrogen sulfide, here the corrosion rate is obviously higher than that caused by Daqing crude oil. There are two modes of storage tank inspection and maintenance that have been currently adopted by Chinese refining and chemical enterprises: a regular inspection mode and a API581-2016 risk-based detection mode. These modes have been effectively combined to form an intelligent tank inspection and maintenance mode, software tools to support this intelligent inspection and maintenance management have been developed.

Adsorption behavior of L_tryptophan on ion exchange resin

Wei Luo,Lei Huang,Hao Chen,Limei Fang,Jin Huang,Zhinan Xu,Peilin Cen 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.5

A batch method was applied to investigate the adsorption behavior and mechanisms of L_tryptophan (Ltrp)on ion exchange resins. HZ-001 and JK006 were proved to be ideal adsorbents due to their large loading capacity and favorable selective adsorption for L-trp. Langmuir, Freundlich, and Dubinin-Radushkevich equations were applied to simulate the experimental data to describe the adsorption process of L_trp onto HZ_001 and JK006. The maximum loading capacity (at pH 5.0, 30 ℃), determined by the Langmuir and Dubinin-Radushkevich models, was close to each other (833 mg/g vs. 874 mg/g) for HZ_001, while discrepant (833 mg/g vs. 935 mg/g) for JK006. Three diffusion-controlled kinetic models were utilized to analyze the results in order to identify the adsorption mechanism. The adsorption kinetics of L_trp onto cation exchange resins was investigated under different experimental conditions, including initial solution pH, temperature, initial L-trp concentration, and adsorbent dosage. Moreover, the diffusion process of L_trp onto HZ_001 and JK006 was evaluated at different initial adsorbate concentrations. The thermodynamic parameters,obtained from the kinetic data, demonstrated that L-trp could be adsorbed spontaneously onto both resins.

Selective hydrogenation of benzene over Ru supported on surface modified TiO2

Fang Hao,Jingsong Zheng,Donghong Ouyang,Wei Xiong,Pingle Liu,Hean Luo 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.4

A series of catalysts with ruthenium nanoparticles (NPs) loaded on the binary oxide TS (TiO2-SiO2) support were prepared by facile sol-gel method for benzene selective hydrogenation. Different mole ratios of Ti/Si were investigated. The catalytic structure, composition, hydrophilicity, electronic state and acidity were characterized. The results indicate that the acidity of the samples increases gradually with the increase of the SiO2 amount. The dispersion of ruthenium nanoparticles was improved on binary oxide support compared with TiO2 and an obvious Ru size effect appeared with the increase of Ti/Si molar ratio. It was also found that the hydrophilicity of the supports could be efficiently improved by introducing a small amount of SiO2 to TiO2, which may be due to the large amount of surface hydroxyl groups on the binary oxide samples after SiO2 introduction. This result was consistent with the increasing trend of cyclohexene yield, indicating that the surface hydroxyl groups play a significant role in the motivation of cyclohexene desorption. Ru/TS (7 : 1) showed the best catalytic performance of 38.2% yield to cyclohexene with the highest initial selectivity to cyclohexene (S0) of 87.3%. The catalytic stability experiments showed that the yield of cyclohexene could maintain at 30% after five cycles.

Nitrogen-doped graphene loaded non-noble Co catalysts for liquid-phase cyclohexane oxidation with molecular oxygen

Fang Hao,Yuan Sun,Yidi Wang,Yang Lv,Pingle Liu,Xiong Wei,Hean Luo 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.8

Selective aerobic oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA oil) with high yield under mild and green conditions is still a significant challenge in the current chemical industry. Herein, nitrogen doped graphene loaded non-noble Co (Co-N-rGO) catalysts, prepared by a facile post-impregnation method, exhibited a high catalytic performance and stability in liquid phase cyclohexane oxidation with molecular oxygen. The experiment and characterization results show that N doping in the catalysts promotes Co metal particle dispersion and induces carbon film coating on Co to prevent leaching and agglomeration. Besides, density functional theory (DFT) calculations show that N doping is beneficial to the O-O bonds breaking in cyclohexyl-hydroperoxides (CHHP), thereby promoting the dissociation of CHHP and enhancing the yield to KA oil. In addition, the catalyst can be easily separated without appreciable loss of catalytic activity after recycling for five times, and show potential industrial application value for the catalytic oxidation of cyclohexane to KA oil in the chemical industry.

Studies on the Isolation , and DNA Identification of Isolates of Tricholoma matsutake

(Dong Fang Zeng),(Xin Chang Luo),(Wei Jie Fu) 한국균학회 2001 Proceedings of the Fifth Korea-China Joint Symposi Vol.- No.-

Network pharmacology and molecular docking reveal the mechanism of Qinghua Xiaoyong Formula in Crohn's disease

Chenyang Fang,Yanni Pei,Yunhua Peng,Hong Lu,Yin Qu,Chunsheng Luo,Yafeng Lu,Wei Yang The Korean Society of Pharmacology 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.4

Crohn's disease (CD) is a chronic inflammatory illness of the digestive system with unknown etiology, and its incidence is increasing worldwide. However, there are currently no effective treatments or medications available for individuals with CD. Therefore, novel therapeutic strategies are urgently needed. The bioactive compounds and targets associated with compounds of Qinghua Xiaoyong Formula (QHXYF) were examined using The Traditional Chinese Medicine Systems Pharmacology database, and 5 disease target databases were also used to identify CD-related disease targets. A total of 166 overlapping targets were identified from QHXYF-related and CD-related disease targets and they were found to be enriched in oxidative stress-related pathways and the PI3K/AKT signaling pathway. Molecular docking was then used to predict how the bioactive compounds would bind to the hub targets. It was found that quercetin could be the core bioactive compound and had good binding affinity to the top 5 hub targets. Finally, animal experiments were performed to further validate the findings, and the results revealed that QHXYF or quercetin inhibited 2,4,6-trinitrobenzenesulfonic acid-induced inflammation and oxidative stress processes by inhibiting the PI3K/AKT pathway, thereby improving CD symptoms. These findings suggest that QHXYF and quercetin may be potential novel treatments for CD.

Investigation of Thermal Response Model for Solar Irradiance Absolute Radiometer

Xiaolong Yi,Wei Fang,Yang Luo,Xin Ye,Dongjun Yang,Yupeng Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.6

A Node Importance Measuring Method based on Hypernetwork

Quan Xiao,Fangli Yang,Song Luo,Lihong Zhang,Hua Zhao,Wei Shu 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.12

Measuring the importance of nodes in network is an important issue in the study of complex networks. The networks in current researches are mostly based on classical graph theory, which have limitations on describing certain complex relations. In this work, we introduce hypernetwork, taking hypergraph as representation foundation, to describe relations. Hypernetwork is able to extend the modeling and describing capability of traditional network and may be a promising representation model of complex relations. However, a general lack of attention to the node importance measuring in hypernetwork, an important fundamental issue for its further application, has been noted across the majority of related published works. In this paper, we utilize the idea of deleting method, to measure the importance of node in hypernetwork through investigating the influence on the whole network when deleting it. Specifically, the influence is measured by direct loss and indirect loss. Through a calculating example, our method is compared with node degree, betweenness, closeness centrality, degree of neighbor nodes etc., the result shows this method has better adaptability and accuracy.

VGLL4 interacts with STAT3 to function as a tumor suppressor in triple-negative breast cancer

Hongming Song,Qifeng Luo,Xiaochong Deng,Changle Ji,Dengfeng Li,Amik Munankarmy,Wei Jian,Junyong Zhao,Lin Fang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Triple-negative breast cancer (TNBC) is an aggressive malignancy with a poor prognosis, and there are no effective molecular-targeted drugs for TNBC patients in clinical practice. The JAK-STAT pathway is implicated in tumorigenesis and the progression of various cancers. In this study, the results demonstrated that VGLL4 is expressed at low levels in both TNBC specimens and cell lines and that VGLL4 expression is negatively correlated with Ki67 expression and tumor size in TNBC patients. VGLL4 knockdown can promote the growth of TNBC cells, while VGLL4 overexpression significantly suppresses the growth of TNBC cells in vitro. More importantly, VGLL4 significantly inhibits tumor progression in a nude mouse model. In addition, VGLL4 is a direct target of miR-454, and the upregulation of miR-454 decreases VGLL4 expression and promotes the cell growth of TNBC cells. Furthermore, we also demonstrated that VGLL4 interacts with STAT3, the core component of the JAK-STAT pathway, leading to the inactivation of STAT3 and the inhibition of STAT3 downstream transcription. Collectively, these findings indicate that VGLL4 expression is negatively associated with poor prognosis in TNBC patients. High expression of miR-454 may be one of the causes of the downregulation of VGLL4 in TNBC, and VGLL4 acts as a tumor suppressor in TNBC by interacting with STAT3 and subsequently suppresses the STAT3 signaling axis, providing potential biomarkers and therapeutic approaches for this fatal disease.