Kyoto University

About: Kyoto University is a education organization based out in Kyoto, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 85837 authors who have published 217215 publications receiving 6526826 citations. The organization is also known as: Kyōto University & Kyōto daigaku.

Complex Phenotype of Mice Lacking Occludin, a Component of Tight Junction Strands

Abstract: Occludin is an integral membrane protein with four transmembrane domains that is exclusively localized at tight junction (TJ) strands. Here, we describe the generation and analysis of mice carrying a null mutation in the occludin gene. Occludin -/- mice were born with no gross phenotype in the expected Mendelian ratios, but they showed significant postnatal growth retardation. Occludin -/- males produced no litters with wild-type females, whereas occludin -/- females produced litters normally when mated with wild-type males but did not suckle them. In occludin -/- mice, TJs themselves did not appear to be affected morphologically, and the barrier function of intestinal epithelium was normal as far as examined electrophysiologically. However, histological abnormalities were found in several tissues, i.e., chronic inflammation and hyperplasia of the gastric epithelium, calcification in the brain, testicular atrophy, loss of cytoplasmic granules in striated duct cells of the salivary gland, and thinning of the compact bone. These phenotypes suggested that the functions of TJs as well as occludin are more complex than previously supposed.

Self-organized nanogratings in glass irradiated by ultrashort light pulses

Abstract: Periodic nanostructures are observed inside silica glass after irradiation by a focused beam of a femtosecond Ti:sapphire laser Backscattering electron images of the irradiated spot reveal a periodic structure of stripelike regions of ~20 nm width with a low oxygen concentration, which are aligned perpendicular to the laser polarization direction These are the smallest embedded structures ever created by light The period of self-organized grating structures can be controlled from ~140 to 320 nm by the pulse energy and the number of irradiated pulses The phenomenon is interpreted in terms of interference between the incident light field and the electric field of the bulk electron plasma wave, resulting in the periodic modulation of electron plasma concentration and the structural changes in glass