Thermodynamics and Kinetics of Lysozyme Adsorption onto Two Kinds of Weak Cation Exchangers

Yong-Mei Cheng,Xiong-Hua Jin,Dong Gao,Hai-Feng Xia,Jing-Hua Chen 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.5

The present work investigated the adsorption behaviors of lysozyme onto weak cation exchangers at different temperatures. The adsorption isotherm, adsorption thermodynamics and adsorption kinetics were studied. The results indicate that the adsorption of lysozyme onto acrylic acid copolymer based beads (Hydrolite D115) is spontaneous and exothermic, while that onto agarose based beads (CM Sepharose 6 Fast Flow) is also spontaneous, but endothermic. The pseudo second-order kinetic model fits well to the dynamic adsorption experimental data, and the kinetic results are also in concert with the adsorption thermodynamics.

One-pot synthesis of high fructose corn syrup directly from starch with SO42−/USY solid catalyst

Yong Sun,Caixia Xiong,Huihui Chen,Xianhai Zeng,Xing Tang,Tingzhou Lei,Lu Lin 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.7

An efficient process was developed for the conversion of starch directly into high fructose corn syrup (HFCS) by using SO4 2−/USY solid catalyst in water. The SO4 2−/USY catalyst was found to act as a bifunctional catalyst with high activity for both hydrolysis of starch and isomerization of glucose, achieving a one-step preparation path of HFCS from starch. An optimal HFCS yield, containing 58.34% glucose and 27.84% fructose (mass fraction), was obtained at 150 oC for only 1 h.

The characteristics of genistin-induced inhibitory effects on intestinal motility

Yong-jian Xiong,Da-peng Chen,Bo-chao Lv,Fang-fei Liu,Li Wang,Yuan Lin 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.3

Genistin belongs to isoflavones. Based on thefacts that genistin exerts inhibitory effects on the contractilityof vascular smooth muscle,the present study wasdesigned to characterize the effects of genistin on intestinalcontractility and evaluate its potential clinical implication. Ex vivo [isolated jejunal segment (IJS) of rat], in vitro, andin vivo assays were used in the study. The results indicatedthat genistin (5–80 lmol/L) inhibited the contraction of IJSin a dose-dependent manner and inhibited the increasedcontractilityof IJS induced by acetylcholine (ACh), histamine,high Ca2?, and erythromycin, respectively. Theinhibitory effects of genistin were correlated with thestimulation of alpha adrenergic and beta adrenergicreceptors since these inhibitory effects were significantlyblocked in the presence of phentolamine and propranololrespectively. No further inhibitory effects of genistin wereobserved in the presence of verapamil or in Ca2?-freecondition, indicating genistin-induced inhibitory effects areCa2?-dependent. Genistin decreased myosin light chainkinase (MLCK) protein contents and MLCK mRNAexpression in IJS, and inhibited both phosphorylation andMg2?-ATPase activity of purified myosin, implicating thatthe decrease of MLCK contents and inhibition of MLCKactivity are involved in the genistin-induced inhibitoryeffects. The study suggests the potential clinical implicationsof genistin in relieving intestinal hypercontractility.

Sulfonated biochar as acid catalyst for sugar hydrolysis and dehydration

Xiong, Xinni,Yu, Iris K.M.,Chen, Season S.,Tsang, Daniel C.W.,Cao, Leichang,Song, Hocheol,Kwon, Eilhann E.,Ok, Yong Sik,Zhang, Shicheng,Poon, Chi Sun Elsevier 2018 CATALYSIS TODAY - Vol.314 No.-

<P><B>Abstract</B></P> <P>This study investigated the use of 30 w/v% H<SUB>2</SUB>SO<SUB>4</SUB> sulfonated wood waste-derived biochar as catalysts for production of value-added chemicals from carbohydrates in water as an environmentally benign solvent. Physicochemical characteristics of the sulfonated biochar were revealed by Fourier transform infrared spectroscopy (FTIR), acid-base neutralization titration, gas adsorption analysis, thermogravimetric analysis (TGA), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Using the sulfonated biochar as catalysts, hydrolysis of maltose at 140–160 °C resulted in the maximum glucose yield of 85.4% and selectivity of 88.2%, whereas dehydration of fructose at 160–180 °C produced the maximum HMF yield of 42.3% and selectivity of 60.4%. A higher range of reaction temperature was required for fructose dehydration due to the higher energy barrier compared to maltose hydrolysis. While increasing the temperature accelerated the catalytic reactions, the maximum product selectivity remained unchanged in the sulfonated biochar-catalyzed systems. The products were stable despite the increase in reaction time, because rehydration and adsorption of products was found to be minor although polymerization of intermediates led to unavoidable carbon loss. This study highlights the efficacy of engineered biochars in biorefinery as an emerging application.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biochar catalyst sulfonated by 30% w/v H<SUB>2</SUB>SO<SUB>4</SUB> achieved 42.3% yield and 58.7% selectivity HMF from fructose. </LI> <LI> Maltose hydrolysis to glucose with yield and selectivity of 85.4% and 88.2% was achieved at lower temperatures. </LI> <LI> Higher temperature accelerated the conversion but did not change the maximum yield and selectivity. </LI> <LI> Energy barrier of dehydration is larger than hydrolysis and requires higher temperature or stronger acidity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Regional Differences and Variability on Enterprise Management Performance: A case in China

Yong qing Xiong,Yun wen Feng,Xiao hong Chen 사람과세계경영학회 2013 Global Business and Finance Review Vol.18 No.2

This paper measures variation in the economic performance of firms using the entropy weight method and cluster analysis. Regional differences and changes in the trend of listed companies' management performance are analyzed in China's four economic regions and 31 provinces from 2006 to 2010, the Eleventh Five Year period. We show that the listed companies' management performance in four economic regions presents a ladder type distribution with large swings and different trends over time. Moreover, there is a large difference in listed companies' management performance across provinces and some provinces have abnormal fluctuations. It is indicated that differences in industrial structures across regions are the main factor determining regional differences in economic development and the variability of enterprise management performance. So from the perspective of policy and institution, some suggestions are advanced to promote integrated development of all regions. In addition, the research results can provide governments at all levels with systematic reference information to formulate a coordinated, sustainable development policy for different regional economies.

Efficient conversion of fructose to 5-[(formyloxy)methyl]furfural by reactive extraction and in-situ esterification

Caixia Xiong,Yong Sun,Juan Du,Wei Chen,Zhihao Si,He Gao,Xing Tang,Xianhai Zeng 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.6

5-[(Formyloxy)methyl]furfural (FMF), an analogue of 5-(hydroxymethyl)furfural (HMF) is becoming more attractive due to its superior stability and hydrophobicity, which make it easier to refineand store. In the present study, FMF was produced from fructose by one-pot approach in pure formic acid media or by a two-step approach via HMF in choline chloride (ChCl)/fructose deep eutectic solvents (DES) system. A favorable FMF yield of 63.22% was reached by two-step approach. In addition, the effects of reaction parameters, such as temperature and acidity, on preparation of FMF from fructose were systematically investigated. The dehydration of fructose into HMF was confirmed as the rate-controlling step in the consecutive reaction. Ultimately, the separation and purification procedures of FMF were put forward. The FMF with a purity of 98.8% was obtained finally. Meanwhile, the FMF purified by saturated sodium bicarbonate solution showed an excelled storage stability.

Enhanced Biological Behavior of Bacterial Cellulose Scaffold by Creation of Macropores and Surface Immobilization of Collagen

Guangyao Xiong,Yizao Wan,Honglin Luo,Chen Zhang,Yong Zhu 한국고분자학회 2015 Macromolecular Research Vol.23 No.8

Bacterial cellulose (BC) is considered a promising three-dimensional (3D) nanofibrous scaffold for tissue engineering. To further improve its biological behavior, BC scaffold was modified by the creation of macropores and the immobilization of collagen (COL) on the surface. The creation of macropores was performed by laser perforation technique and the immobilization of collagen was achieved by solution immersion and subsequent crosslinking. The asprepared macroporous BC/COL nanocomposite (denoted as mBC/COL) was characterized by SEM, FTIR, contact angle measurement, and dynamic mechanical analysis, and its cell behavior was evaluated by MTT assay. SEM and FTIR confirmed the presence of collagen coating and patterned macropores (300 μm). Although the presence of macropores and collagen reduced its storage modulus and hydrophilicity, mBC/COL exhibited sufficient stiffness and wettability. More importantly, preliminary cell studies demonstrated that mBC/COL exhibited improved biological activity over BC and BC/COL due to the co-existence of macropores and collagen.

Finite-time Fault-tolerant Control of Robotic Systems with Uncertain Dynamics

Changgui Xiong,Liang Yang,Bing Zhou,Yong Chen 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

Control of nonlinear robotic systems suffering from actuator failure is a significant, yet challenging problem. In this paper, an observer-based fault-tolerant control method is proposed for robotic systems with external disturbances and modeling discrepancy. Technically, based on the state transform, an unknown input observer is designed to estimate the lumped unknown input. With the aid of the proposed observer, the estimate error is ensured to decay to zero within finite time. Subsequently, the estimated unknown input is utilized to compensate the compound unknown input of the faulty system. The analytical results proved that the tracking error of the closedloop system converges to zero in finite-time, even in the presence of actuator faults. Finally, simulation results are provided to demonstrate the effectiveness of the proposed scheme.

Vasodilation Effect of 2-benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin- 1-one

Wei-Qi,Yong-Xiao Cao,Zhi-Zheng Xiong,Ting-Ting Chen,Xiao-Yan Gao,Hang Yu,San-Qi Zhang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.8

A 2-Benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin-1-one (ZC2) is a newly synthesized isoquinolinone compound. Its effect on vasodilation was evaluated in the present study. Isometric tension of rat artery rings was recorded by a sensitive myography system in vitro. The results showed that ZC2 relaxed rat mesenteric arteries pre-contracted by KCl, phenylephrine and 9, 11- dideoxy- 11α, 9α-epoxymethano-prostaglandin F2α (U46619), and abdominal aorta pre-contracted by KCl in a concentration-dependent manner. The ZC2-induced vasodilation was not affected by an endothelium denudation. ZC2 rightwards shifted the concentration-contraction curves, induced by KCl, phenylephrine, and 5-hydroxytryptamine (5-HT) in a non-parallel manner, which suggests that the vasodilation effects are most likely via voltage-dependent calcium channel (VDCC) and receptor-operated calcium channel (ROCC). Moreover, in Ca2+-free medium, ZC2 concentration-dependently depressed the vasoconstrictions induced by phenylephrine and CaCl2, and decreased a contractile response induced by caffeine, which indicates a role of extracellular Ca2+ influx inhibition through VDCC and ROCC, and intracellular Ca2+ release from Ca2+ store via the ryanodine receptors. Glibenclamide did not affect the vasodilation induced by ZC2, suggesting that ATP sensitive potassium channel is not involved in the vasodilation. The results indicate that ZC2 induces vasodilation by inhibiting the VDCC and ROCC, and receptormediated Ca2+ influx and release. The inhibition of intracellular Ca2+ release may be mediated via the ryanodine receptors.

Limited Unilateral Decompression and Pedicle Screw Fixation with Fusion for Lumbar Spinal Stenosis with Unilateral Radiculopathy : A Retrospective Analysis of 25 Cases

Zhang, Li,Miao, Hai-xiong,Wang, Yong,Chen, An-fu,Zhang, Tao,Liu, Xiao-guang The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.46 No.4

Objective : Lumbar spinal stenosis is conventionally treated with surgical decompression. However, bilateral decompression and laminectomy is more invasive and may not be necessary for lumbar stenosis patients with unilateral radiculopathy. We aimed to report the outcomes of unilateral laminectomy and bilateral pedicle screw fixation with fusion for patients with lumbar spinal stenosis and unilateral radiculopathy. Methods : Patients with lumbar spinal stenosis with unilateral lower extremity radiculopathy who received limited unilateral decompression and bilateral pedicle screw fixation were included and evaluated using visual analog scale (VAS) pain and the Oswestry Disability Index (ODI) scores preoperatively and at follow-up visits. Ligamentum flavum thickness of the involved segments was measured on axial magnetic resonance images. Results : Twenty-five patients were included. The mean preoperative VAS score was $6.6{\pm}1.6$ and $4.6{\pm}3.1$ for leg and back pain, respectively. Ligamentum flavum thickness was comparable between the symptomatic and asymptomatic side (p=0.554). The mean follow-up duration was 29.2 months. The pain in the symptomatic side lower extremity (VAS score, $1.32{\pm}1.2$) and the back (VAS score, $1.75{\pm}1.73$) significantly improved (p=0.000 vs. baseline for both). The ODI improved significantly postoperatively ($6.60{\pm}6.5$; p=0.000 vs. baseline). Significant improvement in VAS pain and ODI scores were observed in patients receiving single or multi-segment decompression fusion with fixation (p<0.01). Conclusion : Limited laminectomy and unilateral spinal decompression followed by bilateral pedicle screw fixation with fusion achieves satisfactory outcomes in patients with spinal stenosis and unilateral radiculopathy. This procedure is less damaging to structures that are important for maintaining posterior stability of the spine.