144 research outputs found
Accessing surface Brillouin zone and band structure of picene single crystals
We have experimentally revealed the band structure and the surface Brillouin
zone of insulating picene single crystals (SCs), the mother organic system for
a recently discovered aromatic superconductor, with ultraviolet photoelectron
spectroscopy (UPS) and low-energy electron diffraction with laser for
photoconduction. A hole effective mass of 2.24 m_0 and the hole mobility mu_h
>= 9.0 cm^2/Vs (298 K) were deduced in Gamma-Y direction. We have further shown
that some picene SCs did not show charging during UPS even without the laser,
which indicates that pristine UPS works for high-quality organic SCs.Comment: 5 pages, 4 figures, Phys. Rev. Lett. 108, 226401 (2012
Mail-in data collection at SPring-8 protein crystallography beamlines
A mail-in data collection system at SPring-8, which is a web application with automated beamline operation, has been developed
Identification of semen from criminal materials by means of paper chromatography--a forensic-medical study
In the present experiments attempts were made to identify semen from various specimens such as the semen itself, spots of semen on clothes, putrefied semen or semen contaminated with blood, menstrual blood, vaginal fluid, according to the techniques of LEVONEN. As the result it has been clarified that in every instance it is possible to isolate and detect the spots of choline by
spraying Dragehdorff's reagent.</p
Photoelectron spectroscopy on the charge reorganization energy and small polaron binding energy of molecular film
AbstractUnderstanding of electron-phonon coupling as well as intermolecular interaction is required to discuss the mobility of charge carrier in functional molecular solids. This article summarizes recent progress in direct measurements of valence hole-vibration coupling in ultrathin films of organic semiconductors by using ultraviolet photoelectron spectroscopy (UPS). The experimental study of hole-vibration coupling of the highest occupied molecular orbital (HOMO) state in ordered monolayer film by UPS is essential to comprehend hole-hopping transport and small-polaron related transport in organic semiconductors. Only careful measurements can attain the high-resolution spectra and provide key parameters in hole-transport dynamics, namely the charge reorganization energy and small polaron binding energy. Analyses methods of the UPS HOMO fine feature and resulting charge reorganization energy and small polaron binding energy are described for pentacene and perfluoropentacene films. Difference between thin-film and gas-phase results is discussed by using newly measured high-quality gas-phase spectra of pentacene. Methodology for achieving high-resolution UPS measurements for molecular films is also described
Implication of Plaque Color Classification for Assessing Plaque Vulnerability A Coronary Angioscopy and Optical Coherence Tomography Investigation
ObjectivesThe purpose of this study was to assess the relationship between plaque color evaluated by coronary angioscopy and fibrous cap thickness estimated by optical coherence tomography (OCT) in vivo.BackgroundYellow color intensity of coronary plaque evaluated by coronary angioscopy might be associated with plaque vulnerability.MethodsSeventy-seven coronary artery plaques in patients with acute coronary syndrome were observed by angioscopy and OCT. Plaque color was graded as white, light yellow, yellow, or intensive yellow.ResultsThere were significant differences among the groups classified by plaque color with respect to the fibrous cap thickness estimated by OCT: 389 ± 74 μm in white plaques, 228 ± 51 μm in light yellow plaques, 115 ± 28 μm in yellow plaques, and 59 ± 14 μm in intensive yellow plaques (p < 0.0001). In Spearman rank-order correlation analysis, there was a significant negative correlation between yellow color intensity and fibrous cap thickness (p < 0.0001). Furthermore, 80% of intensive yellow plaques were thin cap fibroatheroma with a cap thickness of ≤65 μm.ConclusionsThe plaque color in coronary angioscopy was determined by the fibrous cap thickness, which was assessed by OCT. Although coronary angioscopy remains a specialized research tool, it might allow us to evaluate plaque vulnerability
Abrupt rotation of the rashba spin to the direction perpendicular to the surface
金沢大学理工研究域数物科学系The polarization vector of the Rashba spin, which must be parallel to the two-dimensional (2D) plane in an ideal system, is found to change abruptly and definitely to the direction perpendicular to the surface at the K̄ point of the Brillouin zone of a real hexagonal system, the Tl/Si(111)-(1×1) surface. This finding obtained experimentally by angle-resolved and spin-resolved photoemission measurements is fully confirmed by a first-principles theoretical calculation. We found that the abrupt rotation of the Rashba spin is simply understood by the 2D symmetry of the hexagonal structure. © 2009 The American Physical Society
The Iron Discrepancy in Elliptical Galaxies after ASCA
We present estimates for the iron content of the stellar and diffused
components of elliptical galaxies, as derived respectively from integrated
optical spectra and from ASCA X-ray observations. A macroscopic discrepancy
emerges between the expected iron abundances in the hot interstellar medium
(ISM) and what is indicated by the X-ray observations, especially when
allowance is made for the current iron enrichment by Type Ia supernovae. This
strong discrepancy, that in some extreme instances may be as large as a factor
of , calls into question our current understanding of supernova
enrichment and chemical evolution of galaxies. We discuss several astrophysical
implications of the inferred low iron abundances in the ISM, including the
chemical evolution of galaxies and cluster of galaxies, the evolution of gas
flows in ellipticals, and the heating of the intracluster medium. Some of the
consequences appear hard to accept, and in the attempt to avoid some of these
difficulties we explore ways of hiding or diluting iron in the ISM of
ellipticals. None of these possibilities appears astrophysically plausible, and
we alternatively rise the question of the reliability of iron-L line
diagonostic tools. Various thin plasma emission models are shown to give iron
abundances that may differ significantly, especially at low temperatures (kT
\lsim 1 keV). From a collection of ASCA and other X-ray observatory data, it
is shown that current thin plasma codes tend to give very low iron abundances
when the temperature of the objects is below keV. We conclude that --
besides rethinking the chemical evolution of galaxies -- one should also
consider the possibility that existing thin plasma models may incorporate
inaccurate atomic physics for the ions responsible for the iron-L complex.Comment: 39 pages, TeX file, 5 figures, Accepted for publication in the Ap
p62/SQSTM1-droplet serves as a platform for autophagosome formation and anti-oxidative stress response
Autophagy contributes to the selective degradation of liquid droplets, including the P-Granule, Ape1-complex and p62/SQSTM1-body, although the molecular mechanisms and physiological relevance of selective degradation remain unclear. In this report, we describe the properties of endogenous p62-bodies, the effect of autophagosome biogenesis on these bodies, and the in vivo significance of their turnover. p62-bodies are low-liquidity gels containing ubiquitin and core autophagy-related proteins. Multiple autophagosomes form on the p62-gels, and the interaction of autophagosome-localizing Atg8-proteins with p62 directs autophagosome formation toward the p62-gel. Keap1 also reversibly translocates to the p62-gels in a p62-binding dependent fashion to activate the transcription factor Nrf2. Mice deficient for Atg8-interaction-dependent selective autophagy show that impaired turnover of p62-gels leads to Nrf2 hyperactivation in vivo. These results indicate that p62-gels are not simple substrates for autophagy but serve as platforms for both autophagosome formation and anti-oxidative stress. Liquid-liquid phase separation of p62/SQSTM1 has been previously described, although the significance in vivo remains unclear. Here the authors show p62 droplets contain ubiquitin, autophagy-related proteins and Keap1 to serve as platform of not only autophagosome formation but also Nrf2 activation.Peer reviewe
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