Time filter

Source Type

Li K.,Tianjin University | Du S.,Tianjin University | Wu S.,Tianjin University | Cai D.,Shijiazhuang Pharmaceutical Group Ou Yi Co. | And 8 more authors.
Journal of Chemical Thermodynamics | Year: 2016

In this paper, we proposed a static analysis method to experimentally determine the (solid + liquid) equilibrium of racemic oxiracetam in (methanol + water), (ethanol + water) and (isopropanol + water) binary solvents with alcohol mole fraction ranging from 0.30 to 0.90 at atmosphere pressure (p = 0.1 MPa). For the experiments, the temperatures range from (283.15 to 308.15) K. The results showed that the solubility of oxiracetam increased with the increasing temperature, while decreased with the increasing organic solvent fraction in all three tested binary solvent systems. The modified Apelblat model, the CNIBS/Redlich-Kister model, the combined version of Jouyban-Acree model and the NRTL model were employed to correlate the measured solubility values, respectively. Additionally, some of the thermodynamic properties which can help to evaluate its dissolution behavior were obtained based on the NRTL model. © 2015 Elsevier Ltd. All rights reserved. Source

Zheng J.,Shanghai Tofflon Science and Technology Co.
Canadian Journal of Chemical Engineering | Year: 2016

Polyacrylonitrile ultrafiltration membranes have been widely used in many separation processes. In this paper, horseradish peroxidase was immobilized onto polyacrylonitrile ultrafiltration membrane by crosslinking with glutaraldehyde. The immobilized enzyme possessed a protein loading of 0.025mg/cm2 membrane and a specific activity of 105U/mgprotein (105μmol/min/mgprotein). The initial modified and immobilized membranes were observed using SEM and FTIR. Potential applications of HRP membranes were investigated in the removal of phenol through oxidation with the addition of hydrogen peroxide. The optimum pH of the immobilized enzyme was determined to be 6.0, and the optimum hydrogen peroxide concentration to be 30mmol/L. Almost 100% removal of phenol (1∼10mg/L) from water was achieved by HRP membranes. For high concentrated solutions, successive cycles were successfully used to improve the degree of phenol oxidation. Furthermore, the immobilized horseradish peroxidase was operationally stable. These results suggest that the HRP membrane has promising applications for the removal of phenol. © 2016 Canadian Society for Chemical Engineering. Source

Liu W.,Fuzhou University | Cai M.,Fuzhou University | He Y.,Fuzhou University | Wang S.,Fuzhou University | And 2 more authors.
RSC Advances | Year: 2015

A novel antibacterial polyacrylonitrile (PAN) membrane covalently immobilized with lysozyme was prepared. First, the virginal PAN membranes were prepared via the classic immersion precipitation method. After modification with NaOH, HCl, ethylenediamine (EDA), the lysozyme was covalently immobilized onto the surface of the PAN membranes by glutaraldehyde. The chemical compositions of virginal and modified membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and Energy Dispersion X-ray (EDX). The morphology and performance of the immobilized membranes were characterized by Scanning Electronic Microscopy (SEM), filtration performance measurements, the amount of bonded lysozyme, lysozyme activity measurement and flow cytometry method. The antibacterial tests confirmed that the immobilized lysozyme membrane displayed an excellent antibacterial performance against Staphylococcus aureus (S. aureus). © The Royal Society of Chemistry. Source

Li D.,University of Shanghai for Science and Technology | Guo B.,University of Shanghai for Science and Technology | Liu B.,University of Shanghai for Science and Technology | Zhai Z.,University of Shanghai for Science and Technology | And 5 more authors.
Molecular Simulation | Year: 2013

Nowadays heat-sensitive protein medicines are increasingly showing their importance in the treatment of various diseases. Their popularisation and application are meeting a great challenge because of their heat lability. In this study, human insulin as a heat-sensitive protein medicine and 66 amino acids derived from a Group 3 late embryogenesis abundant protein fragment as a complex bioactive protectant, were chosen to be investigated to determine whether these amino acids can be used to protect the insulin from denaturation due to drying. The experiments were carried out by using a replica exchange molecular dynamics (REMD) simulation and GROMACS software with Gromos96 (53a6) force field. The REMD results indicate that those amino acids can effectively prevent the reversal between hydrophilic and hydrophobic surface. Both the configurations and secondary structures of the protected insulin were preserved very well. The H-bonding and electrostatic interactions between the insulin and the protectant play key roles in the bioactive protection of insulin. These results agree well with the water replacement hypothesis. All the results prove that these amino acids are a perfect bioactive protectant for heat-sensitive protein medicines. © 2013 2013 Taylor & Francis. Source

Shanghai Tofflon; Science and Technology Co. | Date: 2009-02-24

Pharmaceutical machinery, namely, lyophilizer machine for freeze drying pharmaceuticals; auto loading and unloading machines, filling machine for small-volume injection, washing machine for vial and closure and aluminum caps.

Discover hidden collaborations