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Ou Z.-M.,Zhejiang University of Technology | Shi H.-B.,Third Affiliated Hospital of Qiqihar Medical College | Sun X.-Y.,Third Affiliated Hospital of Qiqihar Medical College | Shen W.-H.,China Pharma
Journal of Molecular Catalysis B: Enzymatic | Year: 2011

S-licarbazepine was synthesized by asymmetric reduction of oxcarbazepine with CGMCC No. 2266. The optimum batch reduction conditions were found to consist of a reaction time of 36 h, temperature of 30 °C, and initial pH value of 7.0. The optimum concentration of the glucose co-substrate was found to be 0.3 mol L-1. The addition of glucose contributed to in situ regeneration of NADPH in cells and improved conversion. Conversion increased with the addition of more biomass and with a decrease in the initial concentration of substrate. Within the membrane reactor, a continuous reduction process was used to improve production efficiency and reduce the inhibition of high-concentration substrate upon reduction. The optimum flux was found to be 20 ml h-1. S-licarbazepine yield was 3.7678 mmol L-1 d -1 in continuous reduction over four days. The enantiometric excess of S-licarbazepine was 100% for both batch and continuous reduction processes. © 2011 Elsevier B.V. Source

Ou Z.,Zhejiang University of Technology | Chen X.,Zhejiang University of Technology | Ying G.,Zhejiang University of Technology | Shi H.,Third Affiliated Hospital of Qiqihar Medical College | Sun X.,Third Affiliated Hospital of Qiqihar Medical College
Biotechnology and Bioprocess Engineering | Year: 2011

In this study, (S)-3-hydroxy-3-phenylpropionate was prepared continuously by coupling microbial transformation and membrane separation. The effect of several factors on membrane flux, reactor capacity, and reaction conversion were investigated. A kinetic model of the continuous reduction process was also developed. The appropriate molecular weight cut-off of the ultrafiltration membrane was 30 kDa. The reactor capacity reached a maximum of 0.136/h at a biomass concentration and membrane flux of 86 g/L (dry weight/reaction volume) and 20 mL/h, respectively. The (S)-3-hydroxy-3-phenylpropionate yield was 3.68 mmol/L/day after continuous reduction over seven days. The enantiometric excess of (S)-3-hydroxy-3-phenylpropionate reached above 99.5%. The kinetic constants of continuous reduction were as follows: r m = 3.00 × 10 -3 mol/L/h, k cat = 3.49 × 10 -4 mol/L/h, k 1 = 3.09 × 10 -2 mol/L, and k 2 = 5.00 × 10 -7 mol/L. The kinetic model was in good agreement with the experimental data obtained during continuous reduction. Compared with batch reduction, continuous reduction can significantly improve the catalytic efficiency of microbial cells and increase the reactor capacity. © 2011 The Korean Society for Biotechnology and Bioengineering and Springer-Verlag Berlin Heidelberg. Source

Zhimin O.,Zhejiang University of Technology | Xingyuan S.,Third Affiliated Hospital of Qiqihar Medical College | Hanbing S.,Third Affiliated Hospital of Qiqihar Medical College | Hongxia B.,Third Affiliated Hospital of Qiqihar Medical College
Applied Biochemistry and Biotechnology | Year: 2012

(S) -3-Chloro-1-(2-thienyl)-1-propanol was synthesized by the asymmetric reduction of 3-chloro-1-(2-thienyl)propanone with liquid-core immobilized Candida pseudotropicalis 104. The optimum time was 28 h for the re-cultivation of immobilized cells. The optimum film solvent for the liquid-core capsule was 0.3 % chitosan (M w 1.0 × 105). Conversion decreased with the increase of the liquid-core capsule diameter and with the addition of more substrates at the same reduction time. The immobilized cells show good reduction ability in a potassium phosphate buffer (pH 6.6~7.2). The material outside the spread speed of immobilized cells was not restricted when the shaking speed was higher than 160 r/min. Liquid-core immobilized cells can be reused 11 times. Compared with the batch reduction, the continuous reduction of 3-chloro-1-(2-thienyl)propanone in the membrane reactor with liquid-core immobilized cells as catalyst can relieve the inhibition from a high-concentration substrate. Conversion and enantiometric excess of (S)-3-chloro-1-(2-thienyl)-1-propanol reached 100 % and >99 % in a continuous reduction of 12 g/L 3-chloro-1-(2-thienyl)propanone for 10 days. © 2012 Springer Science+Business Media New York. Source

Cai P.-P.,Third Affiliated Hospital of Qiqihar Medical College | Feng Y.,Qiqihar Medical College | Wang D.-H.,Third Affiliated Hospital of Qiqihar Medical College | Zhou Y.,Third Affiliated Hospital of Qiqihar Medical College | And 2 more authors.
World Chinese Journal of Digestology | Year: 2014

Aim: To study the effect of arsenic trioxide (As2O3) on cell growth and cell cycle progression in human colon carcinoma cell line HCT116. Methods: HCT116 cells cultured in vitro were divided into a control group, a 0.5 μmol/L As2O3 group, a 1.5 μmol/L As2O3 group, and a 2.5 μmol/L As2O3 group. After treatment with As2O3 for different durations, the effect of different concentrations of arsenic trioxide on the growth of colon cancer cells was detected by MTT assay. Cell growth curve was plotted to observe the change in cell proliferation. Flow cytometry (FCM) was used to determine cell cycle progression. Results: Low dose of As2O3 (0.5 μmol/L) had no significant inhibitory effect on HCT116 cells compared with the control group (P > 0.05), but 1.5 and 2.5 μmol/L of As2O3 showed a significant inhibitory effect on cell growth in a timedependent manner (38.64% ± 0.16%, 51.42% ± 0.53% vs 8.35% ± 0.76%, P < 0.05 for both). In the 1.5 μmol/L As2O3 group, the inhibitory effect was most obvious on day 3, then gradually declined; however, such a downward trend was not observed in the 2.5 μmol/L As2O3 group (52.93% ± 1.53%). FCM analysis showed that As2O3 at a concentration of 0.5 μmol/L had no significant effect on the percentages of cells in S phase and G2/M phase (35.58% ± 0.63% vs 25.69% ± 1.46%; 33.41% ± 0.73% vs 30.44% ± 1.51%, P > 0.05 for both). However, As2O3 at concentrations of 1.5 μmol/L/L and 2.5 μmol/L significantly increased the percentages of cells in S phase but decreased the percentages of cells in G2/M phase (1.5 μmol/L/L: 42.69% ± 2.64% and 22.46% ± 0.59%; 2.5 μmol/L: 45.71% ± 1.53% and 14.66% ± 0.92%; P < 0.05 for all). Conclusion: Arsenic trioxide has an obvious inhibitory effect on the proliferation of HCT116 cells, mainly by inhibiting the synthesis of DNA in the proliferation stage. The effective dose and treatment time are important in clinical application of As2O3 for cancer chemotherapy in order to improve the effect of chemotherapy, reduce toxicity reactions and delay the occurrence of drug resistance. © 2014 Baishideng Publishing Group Co., Limited. All rights reserved. Source

Sun W.-c.,Third Affiliated Hospital of Qiqihar Medical College | Li Y.-c.,Third Affiliated Hospital of Qiqihar Medical College | Li B.,Third Affiliated Hospital of Qiqihar Medical College | Jiang X.,Third Affiliated Hospital of Qiqihar Medical College | And 3 more authors.
Chinese Journal of Tissue Engineering Research | Year: 2012

BACKGROUND: Small intestinal submucosa is a good scaffold material for cell migration, growth and proliferation, which has been applied in tissue engineering research. OBJECTIVE: To analyze the feasibility of porcine small intestinal submucosa used as the tendon scaffold for tissue engineering. METHODS: Totally 24 Roman chicken with flexor tendon defects of the left leg were randomly divided into experimental group and control group. The composite of porcine small intestinal submucosa and flexor digitorum profoundus tendon in chicken embryos were implanted into the defect area of chicken in the experimental group. The chicken in the control group were implanted with isolated porcine small intestinal submucosa to their defects. Maximum tensile strength of tendon materials in the two groups were detected at weeks 3, 6 and 9 after implantation. RESULTS AND CONCLUSION: At week 3 after implantation, in terms of the maximum tensile strength of tendon materials, there was no significant difference between the experimental group and control group. At weeks 6 and 9 after implantation, the maximum tensile strength of tendon materials in the experimental group was higher than that in the control group (P < 0.05). These findings suggest that the mechanical strength of tissue-engineered tendon scaffolds composited by tendon cells and small intestinal submucosa is stronger than that of tendon repaired by the pure small intestinal submucosa. Small intestinal submucosa can be used as a tendon scaffold material for tissue engineering. Source

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