Low-energy (0.1–2 keV) helium and neon have been scattered from the Al(111) surface to investigate the mechanism of electronic excitation. Neutral He
0 and Ne
0 are (re)ionized during collision with ...Al as a result of one-electron excitation, whereas autoionization occurs preferentially for Ne
+ or Ne
0 incidence due to creation of two core vacancies. It is found that the Ne
2+ ion is formed during collision with Al and its intensity is largely dependent on the charge state of the primary beams; both single-scattering and double-scattering peaks of Ne
2+ emerge from Ne
+ incidence, whereas the double-scattering peaks of Ne
2+ dominates in Ne
0 incidence. This is because Ne
2+ originates from Ne
+ via one-electron excitation provided that the initial vacancy of Ne
+ exists in the 3dπ orbital and another vacancy is newly created in the 4fσ orbital after crossing the band. The predominance of one-electron excitation is characteristic of surface scattering and is basically caused by the band effect of energy-level crossing.
Background. Clinical studies have shown that angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) are able to provide renoprotection independent of their blood pressure lowering effects. ...ARBs also are reported to suppress oxidative stress, inflammation and certain other cellular responses in a receptor-independent manner. We investigated the effects of an ARB, olmesartan, on the cell migration induced by platelet-derived growth factor (PDGF), a major mitogen involved in the pathogenesis of glomerulonephritis in rat mesangial cells (RMCs). Methods. Cell migration was determined by a modified Boyden chamber assay. The intracellular signalling pathway was examined by western blotting. AT1 receptor expression was knocked down by small interfering RNAs. The intracellular reactive oxygen species (ROS) was measured by using a fluorescent probe. The O2·− scavenging activities were studied by the electron paramagnetic resonance-spin trapping method. Results. PDGF-induced cell migration was inhibited by olmesartan in AT1 receptor knockdown RMCs. Olmesartan attenuated big mitogen-activated protein (MAP) kinase 1 (BMK1) and Src activation by PDGF in AT1 receptor knockdown RMCs. PDGF-induced BMK1 activation was suppressed by the Src family tyrosine kinase inhibitors, indicating that Src exists upstream of BMK1. The NADPH oxidase inhibitors inhibited not only PDGF-induced BMK1 and Src activation but also RMC migration. The elevation in ROS generation induced by PDGF was decreased by olmesartan. Olmesartan displayed neither directly ROS scavenging activity nor the inhibition of ROS-mediated intracellular signalling in RMCs. Conclusions. Olmesartan attenuates ROS generation by PDGF, leading to the subsequent inhibition of Src/ BMK1/migration in an AT1 receptor-independent manner in RMCs.
The mechanism of neutralization of and negative ionization from hydrogen ions is studied via experiments in which H
+ beams are incident on LiCl surfaces, combined with molecular-orbital-energy ...calculations. It is found that charge transfer and electron excitation occur due to the resonant-tunneling and electron-promotion mechanisms via a short-lived chemisorption state of hydrogen. The probability for H
+ to H
− conversion at the LiCl surface depends on the species of the target atoms and is enhanced in collision with Li
+ by one order of magnitude relative to Cl
−.
The complex dielectric functions ofβ-rhombohedral boron, of boron carbide with compositions between B4.23C and B10.37C and YB66, were measured between about 2.5 and 9.5 eV. Similarities of the ...electronic structures probably due to the icosahedra are indicated by obvious qualitative similarities of the spectra. Numerous critical points have been determined and confirm the dense sequence of energy bands. Forβ-rhombohedral boron the critical points are compatible with the combined density of states maxima derived from cluster calculations by K. Shirai and H. Nakamatsu (1994,in“Proc. 11th Int. Symp. Boron, Borides and Related Comp, Tsukuba, 1993,” JJAP Series 10, p. 70). Otherwise no satisfactory correlation with theoretical band structure calculations is possible. In the case of boron carbide the critical points are the same within the whole homogeneity range, while the values of the dielectric function at higher energies indicate composition-dependent densities of states, which are correlated with the density of B12icosahedra.
Beamline interlock system and rfBPM interlock system in SPring-8 Matsushita, T.; Nakatani, T.; Ishizawa, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2001, Letnik:
467
Journal Article
Recenzirano
Beamline interlock systems (BL-IS) in SPring-8 were constructed for respective beamlines in accordance with their own components. The systems are based on same architecture. On the other hand when ...the electron beam deviates from the central region of the insertion device (ID), the generated light melts the downstream devices. In order to prevent it, The rfBPM interlock system was constructed. When the rfBPM interlock system detects deviation, it aborts the stored electron beam within 0.8
ms.
This report describes clinicopathological findings, including genetic data of STAT6, in a solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) of the central nervous system in an 83-year-old woman ...with a bulge in the left forehead. She noticed it about 5 months before, and it had grown rapidly for the past 1 month. Neuroradiological studies disclosed a well-demarcated tumor that accompanied the destruction of the skull. The excised tumor showed a prominent papillary structure, where atypical cells were compactly arranged along the fibrovascular core (‘pseudopapillary’). There was rich vasculature, some of which resembled ‘staghorn’ vessels. Mitotic figures were occasionally found. Whorls, psammoma bodies, or intra-nuclear pseudoinclusions were not identified. By immunohistochemistry, CD34 was strongly positive in the tumor cells, and STAT6 was localized in their nuclei. By reverse transcription-polymerase chain reaction (RT-PCR), an
NAB2
-
STAT6
fusion gene,
NAB2 exon6
-
STAT6 exon17
, was detected, establishing a definite diagnosis of SFT/HPC. ‘Papillary’ SFT/HPC needs to be recognized as a possible morphological variant of SFT/HPC, and should be borne in mind in its diagnostic practice.
The structure of a clean Si(001) surface has been studied by a specialized technique in low-energy ion scattering spectroscopy. It has been found that (1) the surface is dimerized, and (2) the ...intradimer atomic distance parallel to the surface is 2.4 plus or minus 0.1 angstrom.
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