Numerical simulation and optimization of impeller combination used in stirred bioreactor / 生物工程学报

Bioreactors have been central in monoclonal antibodies and vaccines manufacturing by mammalian cells in suspension culture. Numerical simulation of five impeller combinations in a stirred bioreactor was conducted, and characteristics of velocity vectors, distributions of gas hold-up, distributions of shear rate in the bioreactor using 5 impeller combinations were numerically elucidated. In addition, genetically engineered CHO cells were cultivated in bioreactor installed with 5 different impeller combinations in fed-batch culture mode. The cell growth and antibody level were directly related to the maximum shear rate in the bioreactor, and the highest viable cell density and the peak antibody level were achieved in FBMI3 impeller combination, indicating that CHO cells are sensitive to shear force produced by impeller movement when cells were cultivated in bioreactor at large scale, and the maximum shear rate would play key roles in scaling-up of bioreactor at industrial scale.

Numerical simulation and performance analysis of mixed flow blood pump / 生物医学工程学杂志

The high rotational speed of the axial flow blood pump and flow separation of the centrifugal blood pump are the main causes for blood damage in blood pump. The mixed flow blood pump can effectively alleviate the high rotational speed and the flow separation. Based on this, the purpose of this study is to explore the performance of the mixed blood pump with a closed impeller. A mixed flow blood pump with closed impeller was studied by numerical simulation in this paper. The flow field characteristics and the pressure distribution of this type of blood pump were analyzed. The hydraulic performance of the blood pump and the possible damages to red blood cells were also discussed. At last, pump performance was compared with the mixed flow blood pump with semi-open impeller. The results show that the mixed flow blood pump with close impeller studied in this paper can operate safely and efficiently with a good performance. The pump can reach the pressure head of 100 mmHg at 5 L/min mass flow rate. Flow in the blood pump is uniform and no obvious separation or vortex occurs. Pressure distribution in and on the impeller is uniform and reasonable, which can effectively avoid the thrombosis of blood. The average mean value of hemolysis index is 4.99 × 10 . The pump has a good biocompatibility. Compared with the mixed flow blood pump with semi-open impeller, the mixed flow blood pump with closed impeller has higher head and efficiency, a smaller mean value of hemolysis index prediction, a better hydraulic performance and the ability to avoid blood damage. The results of this study may provide a basis for the performance evaluation of the closed impeller mixed flow blood pump.

Percutaneous mechanical devices for supporting the left ventricular failure / 中南大学学报(医学版)

This article reviews the indications,contraindications,functionality,and complications for various percutaneous devices that can be used to support the left ventricular failure.We also reviews the anesthetic effect for these devices.A literature review was performed using PubMed.When the heart experiences end-stage systolic ventricular failure,it is generally unable to restore its practical function with pharmacological therapy alone.Percutaneous ventricular support devices have been introduced and used successfully to support a failing ventricle in a variety of settings.These devices include intra-aortic balloon pump,TandemHeart,and Impeller,as well as veno-arterial extracorporeal membrane oxygenation for left ventricular support.These devices are typically accessed percutaneously through the femoral vessels and/or the jugular vein(s),although other sites are possible in unique cases.

El Doctor Juan Marconi Tassara: impulsor de la psiquiatría comunitaria / Doctor Juan Marconi Tassara: community psychiatry impeller

Entre 1968 y 1973 se ensayó en una zona restringida de Santiago una reforma psiquiátrica paralela a los revolucionarios cambios sociopolíticos experimentados en el país. Personaje central de aquella fue el profesor Juan Marconi Tassara quien de investigador universitario se transformó en el líder e impulsor de una radical modificación de la atención psiquiátrica y la salud mental. El profesor desarrolló un modelo de intervención con participación de la comunidad en importantes problemas de salud como el alcoholismo, las neurosis y la privación sensorial que de acuerdo a las investigaciones realizadas beneficiaron a la población. En este artículo se describen los aspectos biográficos y profesionales del Profesor Marconi y sus aportes para la psiquiatría y la salud mental, que si bien fueron criticados desde el comienzo e interrumpidos tras el Golpe Militar, permitieron una vez recuperada la democracia, influir significativamente en la atención de la salud mental en Chile.

Between 1968 and 1973, on a restricted territory of Santiago, a psychiatric reform was developed in parallel to the revolutionary socio-political changes in the country. Central to that reform was professor Juan Marconi Tassara who, from being a university investigator, became the leader and impeller of a radical modification in psychiatric assistance and the mental health. Professor Marconi developed a model of intervention with community participation on important health problems as alcoholism, neurosis and sensorial deprivation that, according to investigations, benefited the population. In this article the biographical and professional aspects of professor Marconi and his contributions for the psychiatric and mental health are described. Although those changes were criticized from the beginning, and interrupted after the military coup, with the recovery of democracy they were a significant influence in the mental health assistance in Chile.