Studies on protein constituents in vertebrate hearts

Organogenesis is a comprehensive phenomenon composed of complicated behavior of heterogenous cell groups which derive from different germ layers, such as ectoderm, mesoderm, and endoderm, at the later stages of animal development. To understand the mechanism of organogenesis many experimental embryologists performed experiments of tissue induction which ...Thesis--University of Tsukuba, D.Sc.(A), no. 616, 1989. 3. 2

マイクロPTVを用いた微小路内における赤血球軸集中挙動の定量的解析

In order to elucidate the effect of red blood cell (RBC) on blood flow at low Reynolds number, the paper aims to examine both distributions and velocity profiles of hardened RBCs in a micro channel varying experimental conditions such as shape and particle Reynolds number. We compare distributions and velocity profiles of both hardened RBCs and spherical particles in a micro channel using a micro PTV (particles tracking velocimetry) system. The micro PTV system consists of a fluorescent microscope equipped with a CMOS camera. Fluorescently-labeled hardened RBCs are suspended in saline within a 100μm square micro channel. In the paper, binarization method with dynamic threshold is applied since the intensity of labeled hardened RBC in the PTV images is too low to calculate the positions and velocities of RBCs. Both the flow velocity profiles and distributions of hardened RBCs are compared with those of the particles in order to clarify the effect of RBC biconcave shape

Occurrence of severe rotavirus gastroenteritis in children younger than three years of age before and after the introduction of rotavirus vaccine: a prospective observational study in four pediatric clinics in Shibata City, Niigata Prefecture, Japan

In Japan, rotavirus (RV) vaccines have already been introduced but not used for universal vaccination as of 2018. Therefore, we identified cases of severe rotavirus gastroenteritis (RVGE) in children younger than three years of age and investigated the occurrence of infection before and after the introduction of RV vaccines. An ecological study through prospective surveillance was conducted in four pediatric clinics in Shibata City, Niigata Prefecture, Japan, during the 2011 to 2018 RVGE epidemic seasons. We divided the study period into three eras: pre-vaccine introduction era (2011), low-mid coverage transitional era (2012 to 2014, RV vaccine coverage rate: 32.9–56.5%), and high coverage plateau era (2015 to 2018, 67.7–81.7%). In this study, the incidence rate of severe RVGE was significantly lower in the plateau era than in the pre-vaccine introduction and transitional eras. Furthermore, the hospitalization rate due to RVGE in Shibata City was lower in the plateau era than in the pre-vaccination introduction and transitional eras. The number of hospitalizations due to RVGE in subjects who required or did not require intravenous rehydration at the pediatric clinics significantly decreased with the increase in vaccine coverage rates by more than 70% in the plateau era

Three-dimensional two-component velocity measurement of the flow field induced by the Vorticella picta microorganism using a confocal microparticle image velocimetry technique

Understanding the biological feeding strategy and characteristics of a microorganism as an actuator requires the detailed and quantitative measurement of flow velocity and flow rate induced by the microorganism. Although some velocimetry methods have been applied to examine the flow, the measured dimensions were limited to at most two-dimensional two-component measurements. Here we have developed a method to measure three-dimensional two-component flow velocity fields generated by the microorganism Vorticella picta using a piezoscanner and a confocal microscope. We obtained the two-component velocities of the flow field in a two-dimensional plane denoted as the XY plane, with an observation area of 455×341 μm2 and the resolution of 9.09 μm per each velocity vector by a confocal microparticle image velocimetry technique. The measurement of the flow field at each height took 37.5 ms, and it was repeated in 16 planes with a 2.50 μm separation in the Z direction. We reconstructed the three-dimensional two-component flow velocity field. From the reconstructed data, the flow velocity field [u(x,y,z),v(x,y,z)] in an arbitrary plane can be visualized. The flow rates through YZ and ZX planes were also calculated. During feeding, we examined a suction flow to the mouth of the Vorticella picta and measured it to be to 300 pl∕s