91 research outputs found
Critical Crossover Between Yosida-Kondo Dominant Regime and Magnetic Frustration Dominant Regime in the System of a Magnetic Trimer on a Metal Surface
Quantum Monte Carlo simulations were carried out for the system of a magnetic
trimer on a metal surface. The magnetic trimer is arranged in two geometric
configurations, viz., isosceles and equilateral triangles. The calculated
spectral density and magnetic susceptibility show the existence of two phases:
Yosida-Kondo dominant phase and magnetic frustration dominant phase.
Furthermore, a critical transition between these two phases can be induced by
changing the configuration of the magnetic trimers from isosceles to
equilateral triangle.Comment: 8 pages, 4 figures; accepted for publication in J. Phys. Soc. Jp
KINEMATICS ANALYSIS OF TWO STYLES OF BOW FOR MARTIAL ARTISTS AND AVARAGE STUDENTS
The aim of this study was to conduct operating analysis of two styles of bow (RITSUREI and ZAREI) for martial artists and average students, and to compare their kinematics characteristic of. Subjects of this study were healthy men (n=33) who were martial artist group (MA, n=18) and average student group (AS, n=15). Subjects conducted RITSUREI and ZAREI three times each. Results of paired t-test, on angular degree parameter of RITSUREI, MA made smaller angular degree of the upper limbs and angular degree of the neck than that of AS. regarding time parameter components, the total time of ZAREI, from beginning of it to stopping, from stopping of it to end, and from beginning of RITSUREI to stopping were significantly shorter than that of AS. MA made several characteristic shown in text. BUDO bow is regarded as practical bow even in social rule when bow teaching is conducte
QTLs for height: results of a full genome scan in Dutch sibling pairs.
Height is a highly heritable, complex trait. At present, the genes responsible for the variation in height have not yet been identified. This paper summarizes the results of previous linkage studies and presents results of an additional linkage analysis. Using data from the Netherlands Twin Register, a sib-pair-based linkage analysis for adult height was conducted. For 513 sib-pairs from 174 families complete genome scans and adult height were available. The strongest evidence for linkage was found for a region on chromosome 6, near markers D6S1053 and D6S1031 (LOD = 2.32). This replicated previous findings in other data sets. LOD scores ranging from 1.53 to 2.04 were found for regions on chromosomes 1, 5, 8, 10, and 18. The region on chromosome 18 (LOD = 1.83) also corresponded with the results of previous studies. Several chromosomal regions are now implied in the variance in height, but further study is needed to draw definite conclusions with regard to the significance of these regions for adult heigh
Analysis of obstetric complications and uterine connective tissue in tenascin-X-deficient humans and mice
Tenascin-X (TNX) is a large, multi-domain, extracellular matrix glycoprotein. Complete deficiency of TNX in humans leads to a recessive form of Ehlers-Danlos syndrome (EDS), and TNX haploinsufficiency is a cause of hypermobility type EDS. EDS patients appear to have a higher risk of several complications during pregnancy, such as pelvic instability, premature rupture of membranes, and postpartum hemorrhage. Here, we present a study of genitourinary and obstetric complications in TNX-deficient women of reproductive age. We have found complications, such as uterus prolapses, that are in agreement with previous findings in other EDS types. In TNX knockout (KO) mice, we have observed mild pregnancy-related abnormalities. Morphological and immunohistological analysis of uterine tissues has not revealed obvious quantitative or spatial differences between TNX KO and wildtype mice with respect to collagen types I, III, V, and XII or elastic fibers. We conclude that TNX-deficient women are at risk of obstetric complications, but that TNX KO mice show only a mild phenotype. Furthermore, we show that TNX is involved in the stability of elastic fibers rather than in their initial deposition
SPARC functions as an inhibitor of adipogenesis
Adipogenesis, a key step in the pathogenesis of obesity, involves extensive ECM remodeling, changes in cell-ECM interactions, and cytoskeletal rearrangement. Matricellular proteins regulate cell-cell and cell-ECM interactions. Evidence in vivo and in vitro indicates that the prototypic matricellular protein, SPARC, inhibits adipogenesis and promotes osteoblastogenesis. Herein we discuss mechanisms underlying the inhibitory effect of SPARC on adipogenesis. SPARC enhances the Wnt/β-catenin signaling pathway and regulates the expression and posttranslational modification of collagen. SPARC might drive preadipocytes away from the status of growth arrest and therefore prevent terminal differentiation. SPARC could also decrease WAT deposition through its negative effects on angiogenesis. Therefore, several stages of white adipose tissue accumulation are sensitive to the inhibitory effects of SPARC
Metallic, magnetic and molecular nanocontacts
Scanning tunnelling microscopy and break-junction experiments realize metallic and molecular nanocontacts that act as ideal one-dimensional channels between macroscopic electrodes. Emergent nanoscale phenomena typical of these systems encompass structural, mechanical, electronic, transport, and magnetic properties. This Review focuses on the theoretical explanation of some of these properties obtained with the help of first-principles methods. By tracing parallel theoretical and experimental developments from the discovery of nanowire formation and conductance quantization in gold nanowires to recent observations of emergent magnetism and Kondo correlations, we exemplify the main concepts and ingredients needed to bring together ab initio calculations and physical observations. It can be anticipated that diode, sensor, spin-valve and spin-filter functionalities relevant for spintronics and molecular electronics applications will benefit from the physical understanding thus obtained
Tunable magnetoresistance in an asymmetrically coupled single molecule junction
Phenomena that are highly sensitive to magnetic fields can be exploited in sensors and non-volatile memories1. The scaling of such phenomena down to the single-molecule level2,3 may enable novel spintronic devices4. Here, we report magnetoresistance in a single-molecule junction arising from negative differential resistance that shifts in a magnetic field at a rate two orders of magnitude larger than Zeeman shifts. This sensitivity to the magnetic field produces two voltage-tunable forms of magnetoresistance, which can be selected via the applied bias. The negative differential resistance is caused by transient charging5,6,7 of an iron phthalocyanine (FePc) molecule on a single layer of copper nitride (Cu2N) on a Cu(001) surface, and occurs at voltages corresponding to the alignment of sharp resonances in the filled and empty molecular states with the Cu(001) Fermi energy. An asymmetric voltage-divider effect enhances the apparent voltage shift of the negative differential resistance with magnetic field, which inherently is on the scale of the Zeeman energy8. These results illustrate the impact that asymmetric coupling to metallic electrodes can have on transport through molecules, and highlight how this coupling can be used to develop molecular spintronic applications
Probing the Site-Dependent Kondo Response of Nanostructured Graphene with Organic Molecules
TCNQ molecules are used as a sensitive probe for the Kondo response of the electron gas of a nanostructured graphene grown on Ru(0001) presenting a moiré pattern. All adsorbed molecules acquired an extra electron by charge transfer from the substrate, but only those adsorbed in the FCC-Top areas of the moiré show magnetic moment and Kondo resonance in the STS spectra. DFT calculations trace back this behavior to the existence of a surface resonance in the low areas of the graphene moiré, whose density distribution strongly depends on the stacking sequence of the moiré area and effectively quenches the magnetic moment for HCP-Top sites. © 2014 American Chemical Society.Financial support by the Ministerio de Educación y Ciencia through Projects CONSOLIDER-INGENIO 2010 on Molecular Nanoscience, FIS2010-18847, FIS 2010-15127, FIS 2010-19609-C02-01, and CTQ2010-17006, and Comunidad de Madrid through the programme NANOBIOMAGNET S2009/MAT1726 is gratefully acknowledged.Peer Reviewe
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