413 research outputs found
Operator analysis of physical states on magnetized orbifolds
We discuss an effective way for analyzing the system on the magnetized
twisted orbifolds in operator formalism, especially in the complicated cases
, and . We can obtain the exact and
analytical results which can be applicable for any larger values of the
quantized magnetic flux M, and show that the (non-diagonalized) kinetic terms
are generated via our formalism and the number of the surviving physical states
are calculable in a rigorous manner by simply following usual procedures in
linear algebra in any case. Our approach is very powerful when we try to
examine properties of the physical states on (complicated) magnetized orbifolds
, , (and would be in other cases on
higher-dimensional torus) and could be an essential tool for actual realistic
model construction based on these geometries.Comment: 41 pages, 1 figur
Classification of three-generation models on magnetized orbifolds
We classify the combinations of parameters which lead three generations of
quarks and leptons in the framework of magnetized twisted orbifolds on
, , and with allowing nonzero discretized
Wilson line phases and Scherk-Schwarz phases. We also analyze two actual
examples with nonzero phases leading to one-pair Higgs and five-pair Higgses
and discuss the difference from the results without nonzero phases studied
previously.Comment: 28 pages (main body and references) + 65 pages (full list of
classification), 22 tables (v1); typos corrected, problem in sentence fixed
(v2
STM observation of the quantum interference effect in finite-sized graphite
Superperiodic patterns were observed by STM on two kinds of finite-sized
graphene sheets. One is nanographene sheets inclined from a highly oriented
pyrolitic graphite (HOPG) substrate and the other is several-layer-thick
graphene sheets with dislocation-network structures against a HOPG substrate.
As for the former, the in-plane periodicity increased gradually in the
direction of inclination, and it is easily changed by attachment of a
nanographite flake on the nanographene sheets. The oscillation pattern can be
explained by the interference of electron waves confined in the inclined
nanographene sheets. As for the latter, patterns and their corrugation
amplitudes depended on the bias voltage and on the terrace height from the HOPG
substrate. The interference effect by the perturbed and unperturbed waves in
the overlayer is responsible for the patterns whose local density of states
varies in space.Comment: 11 pages; 2 figures; accepted for publication in J. Phys. Chem.
Solids; ISIC1
Raman spectroscopic studies on the ferroelectric soft mode in SnxSr1-xTiO3
The Raman spectra of novel ferroelectric ceramics SnxSr1-xTiO3 (x = 0.1, 0.05 and 0.02) were obtained to clarify the mechanism of their ferroelectric phase transitions. Two transverse-optic modes in the ferroelectric phase showed softening toward the ferroelectric transition temperature. A comparison of the spectra obtained for SnxSr1-xTiO3 with the spectrum of PbxSr1-xTiO3 facilitated the assignment of the observed modes under the assumption of the ferroelectric phase in C4v1 symmetry. However, several peaks violating the Raman selection rules were observed, suggesting the emergence and growth of polar regions even in the paraelectric phase
4-Hydroxy-2-Nonenal-Modified Glyceraldehyde-3-Phosphate Dehydrogenase Is Degraded by Cathepsin G in Rat Neutrophils
Degradation of oxidized or oxidatively modified proteins is an essential part of the antioxidant defenses of cells. 4-Hydroxy-2-nonenal, a major reactive aldehyde formed by lipid peroxidation, causes many types of cellular damage. It has been reported that 4-hydroxy-2-nonenal-modified proteins are degraded by the ubiquitin-proteasome pathway or, in some cases, by the lysosomal pathway. However, our previous studies using U937 cells showed that 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase is degraded by cathepsin G. In the present study, we isolated the 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase-degrading enzyme from rat neutrophils to an active protein fraction of 28 kDa. Using the specific antibody, the 28 kDa protein was identified as cathepsin G. Moreover, the degradation activity was inhibited by cathepsin G inhibitors. These results suggest that cathepsin G plays a crucial role in the degradation of 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase
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