Identification and analysis of miRNAs which regulate degranulation activity in mast cells

学位の種別:論文博士University of Tokyo(東京大学

Pseudogap Phase Boundary in Overdoped Bi_2Sr_2CaCu_2O_8 Studied by Measuring Out-of-plane Resistivity under the Magnetic Fields

The characteristic pseudogap temperature T* in Bi2Sr2CaCu2O8 system has been systematically evaluated as a function of doping, especially focusing on its overdoped region, by measuring the out-of-plane resistivity under the magnetic fields. Overdoped samples have been prepared by annealing TSFZ-grown Bi2Sr2CaCu2O8 single crystals under the high oxygen pressures (990 kgf/cm2). At a zero field, the out-of-plane resistivity showed a metallic behavior down to Tc (= 62 K), while under the magnetic fields of over 3 T,it showed typical upturn behavior from around 65 K upon decreasing temperature. This result suggests that the pseudogap and superconductivity are different phenomena.Comment: 2 pages, 2 figures. Final version accepted for the Proceedings of the M2S-IX Conference (Tokyo, September 2009

Visualization of pilot flame of an optically-accessible coaxially-staged aero-engine lean-burn fuel injector

[EN] The visualization of the pilot flame of a coaxially-staged aero-engine lean-burn fuel injector, not only downstream but also inside of the pilot nozzle, was successfully performed at realistic aero-engine conditions. Optical access toward the inside of the nozzle was achieved through the inner and outer shrouds, both of which were made of transparent quartz. The image distortion caused by complex contours of the two shrouds was corrected by a method based on optical ray tracing, which realized precise determination of spatial intensity distribution of optical signals. Line-of-sight OH chemiluminescence, cross-sectional OH-LIF, kerosene LIF and kerosene Mie scattering were employed as diagnostic tools. The effects of pilot local air-to-fuel ratio on spray flame structure were revealed, both inside and downstream of the pilot nozzle under stable combustions. As the pilot mixture got rich, the main reaction zone moved from inside of the pilot nozzle to the region near the injector lip downstream of the injector exit. The OH-LIF signal was detected near the central axis surrounded by the fuel spray. It was also observed near the back-step of the pilot nozzle for the rich cases. The experiments under combustion oscillation were also conducted and the correlation of phenomena inside and downstream of the pilot nozzle was captured. It was clarified that the reaction enhancement in the outer part of the lip vortex region was caused by the convection of rich mixture, which appeared near the pilot atomizer lip at 150~210deg earlier oscillation phase angle.Matsuura, K.; Uesaka, S.; Iwasaki, T.; Kurosawa, Y.; Yamada, H.; Yamamoto, T.; Hayashi, S. (2017). Visualization of pilot flame of an optically-accessible coaxially-staged aero-engine lean-burn fuel injector. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 855-872. https://doi.org/10.4995/ILASS2017.2017.475285587

Elimination of Specific miRNAs by Naked 14-nt sgRNAs

tRNase ZL-utilizing efficacious gene silencing (TRUE gene silencing) is a newly developed technology to suppress mammalian gene expression. TRUE gene silencing works on the basis of a unique enzymatic property of mammalian tRNase ZL, which is that it can recognize a pre-tRNA-like or micro-pre-tRNA-like complex formed between target RNA and artificial small guide RNA (sgRNA) and can cleave any target RNA at any desired site. There are four types of sgRNA, 5′-half-tRNA, RNA heptamer, hook RNA, and ∼14-nt linear RNA. Here we show that a 14-nt linear-type sgRNA against human miR-16 can guide tRNase ZL cleavage of miR-16 in vitro and can downregulate the miR-16 level in HEK293 cells. We also demonstrate that the 14-nt sgRNA can be efficiently taken up without any transfection reagents by living cells and can exist stably in there for at least 24 hours. The naked 14-nt sgRNA significantly reduced the miR-16 level in HEK293 and HL60 cells. Three other naked 14-nt sgRNAs against miR-142-3p, miR-206, and miR-19a/b are also shown to downregulate the respective miRNA levels in various mammalian cell lines. Our observations suggest that in general we can eliminate a specific cellular miRNA at least by ∼50% by using a naked 14-nt sgRNA on the basis of TRUE gene silencing

Hardness Perception Based on Dynamic Stiffness in Tapping

A human can judge the hardness of an object based on the damped natural vibration caused by tapping the surface of the object using a fingertip. In this study, we investigated the influence of the dynamic characteristics of vibrations on the hardness perceived by tapping. Subjectively reported hardness values were related to the dynamic stiffness of several objects. The dynamic stiffness, which characterizes the impulsive response of an object, was acquired across the 40–1,000 Hz frequency range for cuboids of 14 types of materials by administering a hammering test. We performed two psychophysical experiments—a ranking task and a magnitude-estimation tasks—wherein participants rated the perceived hardness of each block by tapping it with a finger. We found that the perceptual effect of dynamic stiffness depends on the frequency. Its effect displayed a peak around 300 Hz and decreased or disappeared at higher frequencies, at which human perceptual capabilities are limited. The acquired results help design hardness experienced by products