Yuki Hirose

A new stiffness evaluation toward high speed cell sorter

Cell stiffness could be an index for evaluating its activity. Although various systems measuring cell stiffness have been proposed so far, they are slow for adaptively connecting to cell sorters capable of handling more than 1000 [cells/sec]. This paper proposes a new approach that can indirectly evaluate the cell stiffness by measuring the passing time for a narrow channel. When a cell passes through the channel, it receives a viscous force depending upon how much deformation is exerted on the cell. We show that the stiffness is a function of both the passing time and the initial diameter of cell. We also show that the stiffness is proportional to the passing time and inversely proportional to the initial diameter, under the assumption that the thickness of fluid film is inversely proportional to the normal force. The experimental validation is given together with the basic working principle.

3-Phosphono-2-(N-cyanoimino)thiazolidine derivatives, new phosphorylating agents for alcohols

Abstract We have developed new phosphorylating agents, 3-phosphono-2-( N -cyanoimino)-thiazolidine derivatives (3-phosphono-NCTs), which were readily synthesized by phosphorylation of NCT, and transformed primary and secondary alcohols into phosphates in good yield. The transfer of three kinds of dialkylphosphono groups [(PhO) 2 P(O)–, (EtO) 2 P(O)–, (Cl 3 CCH 2 O) 2 P(O)–] proceeded in excellent yields. Selective phosphorylation of various alcohols was also accomplished.

Real time vision based cell stiffness evaluation toward 100% guarantee

Stiffness is an important index to know the quality of a cell. While there have been a couple of works to evaluate the cell stiffness in real time by combining a micro fluid chip with electric impedance based cell counters, we can not see what is really happening in the channel after all. The challenge of this paper is to develop a system capable of evaluating the cell stiffness in real time and of checking the measured data toward 100% guarantee. The proposed system is composed of a real time vision and a micro channel. It enables us to capture the data in 5 [msec/cell] in maximum and later to examine whether all data are appropriately obtained or not, by utilizing logged vision data taken at each event. We explain the basic procedure for evaluating the cell stiffness and confirm the effectiveness of the idea through experiments.

5ms-stiffness-evaluation of red blood cell

This paper presents the first challenge for real time stiffness evaluation of red blood cell (RBC) by utilizing both a high speed vision and a micro channel. Since the passing time of cell in the micro channel whose diameter is smaller than that of cell depends upon the stiffness of cell, we can indirectly evaluate the stiffness by the passing time. With the assistance of a high speed vision system, we succeeded in evaluating the stiffness of RBCs with 5 [msec/cell]. The biggest advantage for utilizing a high speed vision is that we can know exactly what is actually happening in the channel, while it is really hard for other approaches. This paper discusses two key ideas for online sensing and shows experimental results.

High speed cell stiffness evaluation toward 100% reliability

This paper proposes a high speed cell stiffness evaluation with high reliability. The procedure includes both online measurement and offline inspection. By using the property where the passing time of the cell in the micro channel is a function of the cell stiffness and its size, a real time vision system whose handling frequency is 6 kHz can capture the size as well as the passing time of each cell. During the online measurement, we save two image data at both the entrance and the exit for each cell. In offline manual inspection, all doubtful data are killed so that we can make sure the reliability. Experimental results ensure that the proposed approach can handle 500 cells within 10min in including both online and offline procedures.