scispace - formally typeset
K

Ko Okumura

Researcher at Juntendo University

Publications -  1123
Citations -  71408

Ko Okumura is an academic researcher from Juntendo University. The author has contributed to research in topics: T cell & Antigen. The author has an hindex of 134, co-authored 1057 publications receiving 67530 citations. Previous affiliations of Ko Okumura include Tokai University & Nagoya City University.

Papers
More filters
Journal ArticleDOI

Evidence for oscillation of atmospheric neutrinos

Y. Fukuda, +124 more
Abstract: We present an analysis of atmospheric neutrino data from a 33.0 kton yr (535-day) exposure of the Super-Kamiokande detector. The data exhibit a zenith angle dependent deficit of muon neutrinos which is inconsistent with expectations based on calculations of the atmospheric neutrino flux. Experimental biases and uncertainties in the prediction of neutrino fluxes and cross sections are unable to explain our observation. The data are consistent, however, with two-flavor ${\ensuremath{ u}}_{\ensuremath{\mu}}\ensuremath{\leftrightarrow}{\ensuremath{ u}}_{\ensuremath{\tau}}$ oscillations with ${sin}^{2}2\ensuremath{\theta}g0.82$ and $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}l\ensuremath{\Delta}{m}^{2}l6\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}3}\mathrm{eV}{}^{2}$ at 90% confidence level.
Journal ArticleDOI

Expression of Programmed Death 1 Ligands by Murine T Cells and APC

TL;DR: B7-H1 was broadly expressed on the surface of mouse tumor cell lines while the expression of B7-DC was rather restricted, and the inducible expression of PD-1 ligands on both T cells and APCs may suggest new paradigms ofPD-1-mediated immune regulation.
Journal ArticleDOI

Involvement of tumor necrosis factor-related apoptosis-inducing ligand in surveillance of tumor metastasis by liver natural killer cells.

TL;DR: It is reported that TRAIL is constitutively expressed on murine natural killer cells in the liver and plays a substantial role in suppressing tumor metastasis and provides the first evidence for the physiological function of TRAIL as a tumor suppressor.
Journal ArticleDOI

Measurement of atmospheric neutrino oscillation parameters by Super-Kamiokande I

Y. Ashie, +135 more
- 01 Jun 2005 - 
TL;DR: In this article, a combined analysis of fully-contained, partially-contained and upward-going muon atmospheric neutrino data from a 1489 d exposure of the Super-Kamiokande detector is presented.
Journal ArticleDOI

Measurements of the solar neutrino flux from Super-Kamiokande's first 300 days

Y. Fukuda, +131 more
TL;DR: The first results of the solar neutrino flux measurement from Super-Kamiokande are presented in this article, where the results are obtained from data taken between 31 May 1996, and 23 June 1997.