Department of Electric Engineering, Faculty of Engineering, Toyama University Chilomonas has almost the same characteristics of cell motility in mannitol and Chalkley's meduim. That is, the cells swim along a wavy path in the absence of an electric field (ordinary movement). When the cells are expose to DC electric field, they display a belt-like distribution perpendicular to the electric field. As the electric field is increased, the cells suddenly skip some 0.5mm after which they perish (breakdown). When AC electric field is applied, the cells show the ordinary movement, swing movement, parallel movement or the breakdown depending on the frequency and the strength of the electric field. The cells perform a Na dance like the Ba dance of Paramecium in NaCI solution and a rotational movement with a frequency of about 2Hz in CaCl2 solution. The ratio of the cells which perform the latter movement is increased by application of the AC electric field.
A practical inversion technique obtaining size distribution from the light scattering pattern is presented for two-dimensional particles. This technique is an improvement on the two-dimensional inversion technique formerly proposed by the present authors. We also show a method to compensate the calculation error which originates from the finite measuring range of scattering pattern. It is proved by a computer simulation that the present method can give good results. The utility of this technique is experimentally demonstrated by the size distribution measurement of bacteria fixed on a slide-glass.
In higher plant cells, measurement of the intracellular pH (cytoplasmic and vacuolar pH) has proved very difficult because of the existence of vacuoles in the cells. Here, we investigated the intracellular pH of higher plant cells (mung bean root tip cells) by using 31P-NMR. Estimations of the cytoplasmic and vacuolar pH were made from the P. chemical shifts of cytoplasm and vacuole, respectively. In this paper, we propose a 31P-NMR perfusing system. Using this system, we can investigate the cytoplasmic and vacuolar pH and the H+ efflux simultaneously at room temperature. As the measurement of intracellular pH using the 31P-NMR perfusing system is a noninvasive and nondestructive method, we believe that this method will play an important role in the future study of intracellular pH regulation mechanism.
The dependence on conditions of preparation of evaporated ZnSe thin films was investigated by X-ray diffraction and optical transmission. In the films deposited from ZnSe powder containing excess Zn and Se, a growth of crystallite size in the film was observed when annealed at 300°C for 480 minutes, whereas, in the films deposited from pure ZnSe powder, no crystallite size growth was observed by annealing. Furthermore, the X-ray diffraction intensity of (111) plane decreased while that of (311) plane increased with increasing substrate temperature in the range of 80_??_300°C. This means that when crystalline nuclei appear in the first stage on the substrate, the crystalline plane of the nuclei differs with substrate temperature.
Tokai Research Establishment, Japan Atomic Energy Research Institute A nondestructive method has been studied for determining the concentration of radionuclide (Cs-137) distributed in a soil column. The concentration distribution was calculated from the counting rate distribution using the efficiency matrix of a detector. The concentration distribution obtained by this method, with measuring efficiencies of theoretical calculation, coincides well with that obtained by the destructive sampling method. This method is, therefore, found to be effective for the measurement of one dimensional concentration distribution. The measuring limit of this method is affected not only by the radionuclide concentration but also by the shape of concentration distribution in a soil column and also by the way it is divided into concentration blocks. It is found that, the radioactive concentration up to 2.6×10-4μCi/g (9.62Bq/g), and also the distribution up to where the concentration reduces to half at every 1cm of depth, can be measured by this system. The concentration blocks can be divided into 1cm of thickness as a minimum value.