RESUMO
Polyacrylonitrile nanofiber membrane functionalized with tris(hydroxymethyl)aminomethane (P-Tris) was used in affinity membrane chromatography for lysozyme adsorption. The effects of pH and protein concentration on lysozyme adsorption were investigated. Based on Langmuir model, the adsorption capacity of P-Tris nanofiber membrane was estimated to be 345.83 mg/g. For the operation of dynamic membrane chromatography with three-layer P-Tris nanofiber membranes, the optimal operating conditions were at pH 9, 1.0 mL/min of feed flow rate, and 2 mg/mL of feed concentration. Chicken egg white (CEW) was applied as the crude feedstock of lysozyme in the optimized dynamic membrane chromatography. The percent recovery and purification factor of lysozyme obtained from the chromatography were 93.28% and 103.98 folds, respectively. Our findings demonstrated the effectiveness of P-Tris affinity nanofiber membrane for the recovery of lysozyme from complex CEW solution.
Assuntos
Cromatografia de Afinidade/métodos , Clara de Ovo/química , Muramidase/isolamento & purificação , Nanofibras/química , Trometamina/química , Adsorção , Membranas Artificiais , Muramidase/químicaRESUMO
A novel pulse-diagnosis system was proposed in this study for measuring pulse wave velocities. In contrast with most conventional mechanical, rigid-type pulse diagnosis instruments such as pressure transducers and microactuators, a conductive elastic polymer was adopted as the sensor material. The soft and formability properties of such material enabled fabricating a flexible pulse diagnosis instrument. In addition, the flexible design was integrated with a contemporary, wrist-type pulse-wave acquisition system to ensure stable measurements. Closely related to the incidence of cardiovascular diseases, pulse wave velocity was analyzed in applications to verify the feasibility of this system. Regarding signal processing, the cun, guan, and chi pulse signals obtained through the data acquisition device were sent to the LabVIEW platform for reconstructing the pulse waveforms. Finally, the results of 20 measured samples were compared and analyzed to evaluate the level of system performance.
Assuntos
Artérias/fisiologia , Frequência Cardíaca/fisiologia , Polímeros , Fluxo Pulsátil/fisiologia , Análise de Onda de Pulso/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Desenho de Equipamento , HumanosRESUMO
A novel pulse-diagnosis system was proposed in this study for measuring pulse wave velocities. In contrast with most conventional mechanical, rigid-type pulse diagnosis instruments such as pressure transducers and microactuators, a conductive elastic polymer was adopted as the sensor material. The soft and formability properties of such material enabled fabricating a flexible pulse diagnosis instrument. In addition, the flexible design was integrated with a contemporary, wrist-type pulse-wave acquisition system to ensure stable measurements. Closely related to the incidence of cardiovascular diseases, pulse wave velocity was analyzed in applications to verify the feasibility of this system. Regarding signal processing, the cun, guan, and chi pulse signals obtained through the data acquisition device were sent to the LabVIEW platform for reconstructing the pulse waveforms. Finally, the results of 20 measured samples were compared and analyzed to evaluate the level of system performance.
