A way of computer use in mathematics teaching -The effectiveness that visualization brings-

We report a class of the mathematics in which an animation technology (calculating and plotting capabilities) of the software Mathematica is utilized. This class is taught for university students in a computer laboratory during a second semester. It is our purpose to make a student realize the usefulness and the importance of mathematics easily through visualization. In addition, we hope that students will acquire a new power of mathematics needed in the 21st century. For several years, we have continued this kind of class, and have continued to investigate the effectiveness that our teaching method (especially visualization) brings in the understanding of the mathematics. In this paper, we present some of this teaching method, which is performed in our class. From the questionnaire survey, it is found that our teaching method not only convinces students that the mathematics is useful or important but also deepens the mathematic understanding of students more

Continuous downstream process of monoclonal antibody developed based on the process analysis/understanding and its validation

As downstream process (DSP) of monoclonal antibody (mAb) includes several batch chromatography steps, and other operations such as virus inactivation (VI), it is important to consider how each operation is carried out in order to make an efficient continuous or pseudo-continuous DSP. Our consortium* developed a continuous DSP (CDSP) of mAb under the AMED** project “Development of platform technologies for the continuous manufacturing of biopharmaceuticals”, and successfully carried out several runs at our GMP facility and laboratory. In this paper, we will present how our CDSP was developed based on the process analysis and understanding, and the purification results along with several important issues to be addressed in the future [1]. For the first “capture” step, a 2-column “periodic counter-current chromatography (PCCC)” with protein A chromatography columns was chosen. The efficiency of PCCC is strongly dependent on the operating conditions, which should be determined properly [2, 3]. Please click Additional Files below to see the full abstract

Flow-through chromatography as a continuous and integrated purification method

Continuous manufacturing is expected to improve the efficiency and economics of protein and other bio-product production processes. However, it is not easy to design and operate the continuous process especially for downstream processing as many unit operations (chromatography and membrane filtration) are involved. An operation method known as flow-through chromatography (FTC) is considered to be an efficient purification method as the flow is continuous. In FTC, a target bio-product is eluted from the chromatography column without adsorption whereas contaminants are strongly bound. Usually two different modes of chromatography are needed in order to remove various kinds of contaminants. Two FTC columns have to be connected in order to build the integrated continuous process. This is not an easy task since the mobile phase properties (pH, salt, buffer ions) are different for the two columns. Please click Additional Files below to see the full abstract

Flow-velocity programmed chromatography as an alternative method for increasing the efficiency of continuous- or integrated-chromatography processes

Solvent (mobile phase) programming is most commonly employed for controlling adsorption/desorption in chromatography (linear gradient elution or stepwise elution). For gas separation, temperature- or pressure-swing adsorption is frequently used. Although flow-velocity is another important parameter, which affects both the dynamic adsorption capacity (DBC) and the resolution, it is seldom used as a programmed operating variable. The one exception is the standard 4-zone simulated moving bed (SMB) chromatography, in which the flow-velocities of the 4-zones are different. Several researchers have already shown that DBC can be increased by using two different flow velocities. However, a rational method for determining the optimum flow velocity program has not been established. Moreover, application of this method to periodic counter-current (PCC) chromatography or connected flow-through chromatography (FTC) has not been attempted yet. In this study, we have developed a flow-velocity gradient method for analyzing the breakthrough curves of proteins in ion-exchange or protein A chromatography (Figure 1). The data were obtained at various different gradient slopes. The obtained curves were analyzed based on a model considering mass transfer (pore diffusion) and non-linear isotherm. Then, numerical simulations were carried out in order to find the optimum flow-velocity program for improving the efficiency. This method was further applied to PCC and FTC (Figure 2). The effect of flow programming on productivity and cost reduction has also been examined in both batch and continuous configuration in capture chromatography of mAbs by simulation of the process models. Experimental verification was also carried out using monoclonal antibody samples in the filtered cell culture liquid. Please click Additional Files below to see the full abstract

High-Gain Power Recycling of a Fabry Perot Michelson Interferometer for a Gravitational-Wave Antenna

Power recycling was implemented on a fully suspended prototype interferometer with arm lengths of 20 m. A wave-front-sensing technique for alignment control of the suspended mirrors was also implemented, which allowed for several hours of stable operation. A power-recycling gain of greater than 12 was achieved, a significant increase over the highest gain in a suspended mirror Fabry Perot Michelson interferometer reported to date