3,955 research outputs found
Spin-polarized electronic structures and transport properties of Fe-Co alloys
The electrical resistivities of Fe-Co alloys owing to random alloy disorder
are calculated using the Kubo-Greenwood formula. The obtained electrical
esistivities agree well with experimental data quantitatively at low
temperature. The spin-polarization of Fe50Co50 estimated from the conductivity
(86%) has opposite sign to that from the densities of the states at the Fermi
level (-73%). It is found that the conductivity is governed mainly by
s-electrons, and the s-electrons in the minority spin states are less
conductive due to strong scattering by the large densities of the states of
d-electrons than the majority spin electrons.Comment: 3 pages, 4 figure
Torsion in Milnor fiber homology
In a recent paper, Dimca and Nemethi pose the problem of finding a
homogeneous polynomial f such that the homology of the complement of the
hypersurface defined by f is torsion-free, but the homology of the Milnor fiber
of f has torsion. We prove that this is indeed possible, and show by
construction that, for each prime p, there is a polynomial with p-torsion in
the homology of the Milnor fiber. The techniques make use of properties of
characteristic varieties of hyperplane arrangements.Comment: Published by Algebraic and Geometric Topology at
http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-16.abs.htm
Morphological characteristics of the deep layer of articularis genus muscle
Background: The articularis genus muscle pulls the suprapatellar pouch upwards when the knee joint is extended, preventing mechanical impingement of the joint capsule which theoretically could cause anterior knee pain. However, few anatomical studies have addressed this muscle. Here we present the precise morphology of articularis genus.Materials and methods: A total of 22 (13 male and 9 female) adult cadavers with no pathological conditions in the knee joints were examined during educational dissection at Nagoya City University Medical School in 2012. After exclusion of 4 joints due to their flexion contracture, 40 knee joints (18 right and 22 left) were analysed. We performed statistical analysis on anatomical laterality and the difference of sizes among lateral, medial and central branches and studied the correlation of the length and area of the articularis genus muscle to the lengthand cross-section area of the femur.Results and Conclusions: The average number of branches of the deep layer of the articularis genus muscle was 2.7 ± 0.5, the mean length of all brancheswas 5.4 ± 1.3 cm and the mean area of all branches was 5.5 ± 2.6 cm2. There was no significant correlation between the length and area of the articularis genus muscle to the length and cross-section area of the femur. There was no significant laterality in central, medial and lateral branches; however we found that the medial branch was statistically longer and larger than the lateral branchon either knee. This could be contributing to prevention of lateral dislocation of the patella
Translated tori in the characteristic varieties of complex hyperplane arrangements
We give examples of complex hyperplane arrangements for which the top
characteristic variety contains positive-dimensional irreducible components
that do not pass through the origin of the character torus. These examples
answer several questions of Libgober and Yuzvinsky. As an application, we
exhibit a pair of arrangements for which the resonance varieties of the
Orlik-Solomon algebra are (abstractly) isomorphic, yet whose characteristic
varieties are not isomorphic. The difference comes from translated components,
which are not detected by the tangent cone at the origin.Comment: Revised and expanded; 16 pages, 10 figures; to appear in Topology and
its Application
An anatomic study of the accessory anterolateral talar facet
Background: A small accessory facet with articular surface morphology is occasionally seen on the talus, bordering on the lateral end of the sinus tarsi. This facet has been named the accessory anterolateral talar facet. However, few anatomical studies have addressed this facet. Here we present the precise morphology of accessory anterolateral talar facet with emphasis on anatomical correlation between the presence of this facet and the angle of the infero-lateral surface of the talus (talar infero-lateral surface — TILS angle). Materials and methods: A total of 22 (11 male, 11 female) adult cadavers with no known pathological conditions in the talocalcaneal joints were examined during educational dissection at Nagoya City University Medical School in 2013. After exclusion of 1 joint due to the poor condition of the talus, 43 talus (22 right, 21 left) were analysed. We judged the presence of the accessory anterolateral talar facet and measured TILS angle. We performed statistical analysis on the point of laterality, gender difference and the difference in the TILS angles in tali with or without the accessory anterolateral talar facets. Results: An accessory anterolateral talar facet was identified in 11 (26%) of the 43 specimens. Of the 21 cadavers with paired talar specimens, 5 displayed the facet bilaterally. Conclusions: There was no sex difference and no significant laterality, however we found that TILS angle was significantly larger in accessory anterolateral talar facet positive samples than in negative ones
Low-molecular weight heparin protamine complex augmented the potential of adipose-derived stromal cells to ameliorate limb ischemia
Center for Regenerative Medicine, Research Support Center, Dokkyo Medical University, Mibu, Tochigi, JapanCenter for Regenerative Medicine, Research Support Center, Dokkyo Medical University, Mibu, Tochigi, JapanCenter for Regenerative Medicine, Department of Cardiovascular Medicine, Dokkyo Medical University, Mibu, Tochigi, JapanCenter for Regenerative Medicine, Department of Cardiovascular Medicine, Dokkyo Medical University, Mibu, Tochigi, JapanCenter for Regenerative Medicine, Research Support Center, Dokkyo Medical University, Mibu, Tochigi, Japan:Department of Cardiology, Koshigaya Hospital, Dokkyo Medical University, Koshigaya, Saitama, JapanCenter for Regenerative Medicine, Research Support Center, Department of Cardiovascular Medicine, Dokkyo Medical University, Mibu, Tochigi, JapanCenter for Regenerative Medicine, Dokkyo Medical University, Mibu, Tochigi, Japa
Lipid membrane deformation in response to a local pH modification: theory and experiments
We study the deformation of a lipid membrane in response to a local pH
modification. Experimentally, a basic solution is microinjected close to a
giant unilamellar vesicle. A local deformation appears in the zone of the
membrane that is closest to the micropipette, and relaxes when the injection is
stopped. A theoretical description of this phenomenon is provided. It takes
fully into account the spatiotemporal evolution of the concentration of
hydroxide ions during and after the microinjection, as well as the linear
dynamics of the membrane. This description applies to a local injection of any
substance that reacts reversibly with the membrane lipids. We compare
experimental data obtained in the domain of small deformations to the results
of our linear description, and we obtain a good agreement between theory and
experiments. In addition, we present direct experimental observations of the pH
profile on the membrane during and after the microinjection, using pH-sensitive
fluorescent lipids.Comment: 11 pages, 8 figure
Dilution and clustering of Fe in the rutile phases of TiO2 and SnO2
ABSTRACT: Dilute magnetic semiconductors of Fe-doped SnO2 and TiO2 with the structure of rutile were prepared in forms of powder and thin films using the techniques of sol gel and pulsed-laser deposition. We present the results of measurement of vibrational density of states of Fe impurity dopants in these oxides and demonstrate the cases of dilution and clustering. The oxygen pressure during the film deposition was varied between 10−1 and 10−8 Torr. In TiO2 films made at 10−1 Torr, Fe is diluted, however, in films made at 10−8 Torr Fe is clustered. The case of true Fe dilution in SnO2 is also shown. In spite of larger mass defect for Fe in SnO2 than that for Fe in TiO2 the dilute Fe species probe the phonon states in SnO2 more faithfully than in TiO2. This result is understood in terms of the combined effect of mass defect and nearest-neighbor force-constant changes. The impurity modes are more pronounced in TiO2 than in SnO2 due to ca. 10% difference of the lattice cell volumes between these two rutile oxides
Drosophila Strip serves as a platform for early endosome organization during axon elongation
Early endosomes are essential for regulating cell signalling and controlling the amount of cell surface molecules during neuronal morphogenesis. Early endosomes undergo retrograde transport (clustering) before their homotypic fusion. Small GTPase Rab5 is known to promote early endosomal fusion, but the mechanism linking the transport/clustering with Rab5 activity is unclear. Here we show that Drosophila Strip is a key regulator for neuronal morphogenesis. Strip knockdown disturbs the early endosome clustering, and Rab5-positive early endosomes become smaller and scattered. Strip genetically and biochemically interacts with both Glued (the regulator of dynein-dependent transport) and Sprint (the guanine nucleotide exchange factor for Rab5), suggesting that Strip is a molecular linker between retrograde transport and Rab5 activation. Overexpression of an active form of Rab5 in strip-mutant neurons suppresses the axon elongation defects. Thus, Strip acts as a molecular platform for the early endosome organization that has important roles in neuronal morphogenesis.This work was supported by grants from the National Institute of General Medical Science of the National Institutes of Health (R01-GM085232 to V.I.G.), the National Institutes of Health (R01-DC005982 to L.L.), the Japanese Ministry of Education, Science, Sports, Culture, and Technology (MEXT), the Japan Society for the Promotion of Science, and the Japan Science and Technology Agency (to C.S., K.T., Y.Y., M.M., and T.C.)
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