Toshihiko Yoshino

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Erythroblastic islands are anatomical units consisting of a central macrophage surrounded by erythroblasts. We studied the adhesion molecules involved in the formation of these structures. Central macrophages of erythroblastic islands isolated from the spleens of phlebotomized mice were clearly stained for vascular cell adhesion molecule 1 (VCAM-1). The(More)
Erythropoiesis occurs in the presence of erythropoietin (EPO) without macrophages in vitro. In hematopoietic tissues, however, erythroid cells associate closely with stromal macrophages, forming erythroblastic islands via interactions with adhesion molecules. To elucidate the role of macrophages in erythropoiesis, we selectively abrogated stromal(More)
A new scheme of the Faraday effectcurrent sensor of a magnetic ring-core type is reported. With this scheme a uniaxial magnetic garnet film is obliquely inserted into a very narrow gap in the ring core and a probe light beam is passed through the garnet film in the transverse direction to the core. It is experimentally demonstrated that this current sensor(More)
An optical fiber sensor is presented that allows current and voltage to be measured simultaneously by use of only one block of bismuth germanate crystal. The polarized light from the sensing crystal is split into two light beams: One beam is utilized for current measurement based on the Faraday effect, and the other one is utilized for voltage measurement(More)
To stabilize the phase-shifting Fizeau-type interferometer against environmental disturbances (namely, vibration and temperature variations), the feedback scheme that uses the current-induced frequency modulation of a laser diode (lambda = 633 nm) and the two-frequency optical heterodyne method has been investigated, with particular attention to improvement(More)
A new scheme is proposed for achieving a closed, homogeneous, and isotropic optical circuit necessary for high-accuracy optical-current sensors. It makes use of a single solid polygonal solid with reflection surfaces coated by quarter-wavelength dielectric thin-film layers for the Faraday cell. We derive the design principle and show numerically its(More)
A closed-loop phase-shifting Fizeau-type interferometer was constructed that uses direct frequency modulation of a laser diode. The interferometer is servo controlled entirely in the phase domain, where optical phases are detected by two-frequency optical heterodyning. A detailed study of stabilization of the interferometer under feedback control was(More)
A two-dimensional noncontact optical fiber water droplet sensorthat uses the fluorescence from a laser-diode-pumpedTm(3+):YAG and that uses a single fiber bundle for the probefiber has been constructed. The sensor is based on absorptionspectroscopy but has the significant advantage that the residual pumplight works for the reference signal. The water depth(More)
A novel magneto-optic sensor with electrically adjustable sensitivity is proposed that is based on the approximate multiplication correlation between the linear electro-optic phase retardation and the Faraday magneto-optic rotation angle in a single bismuth germanate crystal. The measurement sensitivity and its temperature stability, linear and monotonic(More)