3,915 research outputs found
Hall Resistivity in Ferromagnetic Manganese-Oxide Compounds
Temperature-dependence and magnetic field-dependence of the Hall effect and
the magnetic property in manganese-oxide thin films are studied. The
spontaneous magnetization and the Hall resistivity are obtained for a various
of magnetic fields over all the temperature. It is shown that the Hall
resistivity in small magnetic field is to exhibit maximum near the Curie point,
and strong magnetic field moves the position of the Hall resistivity peak to
much high temperature and suppresses the peak value. The change of the Hall
resistance in strong magnetic field may be larger than that of the diagonal
ones. The abnormal Hall resistivity in the ferromagnetic manganese-oxide
thin-films is attributed to the spin-correlation fluctuation scattering.Comment: Latex, 2 Figures, 10 Page
Chrysin suppresses lipopolysaccharide-induced cyclooxygenase-2 expression through the inhibition of nuclear factor for IL-6 (NF-IL6) DNA-binding activity
AbstractChrysin is a natural, biologically active compound extracted from many plants, honey and propolis. It possesses potent anti-inflammation, anti-cancer and anti-oxidation properties. The mechanism by which chrysin suppresses COX-2 expression remains poorly understood. In the present report, we investigated the effect of chrysin on the expression of COX-2 in lipopolysaccharide (LPS)-activated Raw 264.7 cells. Chrysin significantly suppressed the LPS-induced COX-2 protein and mRNA expression in a dose-dependent manner. The ability of chrysin to suppress the expression of the COX-2 was investigated using luciferase reporters controlled by various cis-elements in COX-2 promoter region. Mutational analysis and electrophoretic mobility shift assay verified that nuclear factor for IL-6 was identified as responsible for the chrysin-mediated COX-2 downregulation. These results will provide new insights into the anti-inflammatory and anti-carcinogenic properties of chrysin
Isotropic photonic band gap and anisotropic structures in transmission spectra of two-dimensional 5-fold and 8-fold symmetric quasiperiodic photonic crystals
We measured and calculated transmission spectra of two-dimensional
quasiperiodic photonic crystals (PCs) based on a 5-fold (Penrose) or 8-fold
(octagonal) symmetric quasiperiodic pattern. The photonic crystal consisted of
dielectric cylindrical rods in air placed normal to the basal plane on vertices
of tiles composing the quasiperiodic pattern. An isotropic photonic band gap
(PBG) appeared in the TM mode, where electric fields were parallel to the rods,
even when the real part of a dielectric constant of the rod was as small as
2.4. An isotropic PBG-like dip was seen in tiny Penrose and octagonal PCs with
only 6 and 9 rods, respectively. These results indicate that local multiple
light scattering within the tiny PC plays an important role in the PBG
formation. Besides the isotropic PBG, we found dips depending on the incident
angle of the light. This is the first report of anisotropic structures clearly
observed in transmission spectra of quasiperiodic PCs. Based on rod-number and
rod-arrangement dependence, it is thought that the shapes and positions of the
anisotropic dips are determined by global multiple light scattering covering
the whole system. In contrast to the isotropic PBG due to local light
scattering, we could not find any PBGs due to global light scattering even
though we studied transmission spectra of a huge Penrose PC with 466 rods.Comment: One tex file for manuscript and 12 PNG files for figures consisting
of Fig.1a-d, 2,3, ...
Scanning Tunneling Microscopy Measurements of the Local Work Function around Steps on the Au/Cu(111) Surface(STM-local states)
With a scanning tunneling microscope we have taken local work function images of the Au/Cu(111) surface. The local work function measured from large Au-covered terraces is in good agreement with the result obtained by non-local techniques, and the local work function around step edges is significantly lower than that on terraces. The experimental details of the local work function lowering around a step can be reproduced nicely with a simple simulation if a dipole moment row with a proper linear density is put at the center of the step and if the influence of the topographic change of the step due to formation of the dipole moment is taken into account. It is demonstrated that STM has the ability to reveal the details of how local work function varies around steps and other defects on metal surfaces
On the sample size dependence of the critical current density in MgB superconductors
Sample size dependent critical current density has been observed in magnesium
diboride superconductors. At high fields, larger samples provide higher
critical current densities, while at low fields, larger samples give rise to
lower critical current densities. The explanation for this surprising result is
proposed in this study based on the electric field generated in the
superconductors. The dependence of the current density on the sample size has
been derived as a power law ( is the factor
characterizing curve ). This dependence provides one with
a new method to derive the factor and can also be used to determine the
dependence of the activation energy on the current density.Comment: Revtex, 4 pages, 5 figure
Recommended from our members
Icosahedral and dodecagonal quasicrystal plus glass alloys with plastic deformability
Analysis of Infant Microbiota Composition and the Relationship With Breast Milk Components in the Asian Elephant (Elephas Maximus) at the Zoo
The prevention of diseases through health control is essential at zoos. Here, we investigated the gut microbiota formation during infancy in an Asian elephant and compared the composition between infant and mother. Besides, we analyzed the components of breast milk and examined the correlation with the infant gut microbiota. Analysis revealed the gut microbiota of the infant contained high amount of Lactobacillales and its diversity was relatively low compared to that of the mother. We found several milk components, showed a positive correlation with the change of Lactobacillales. The present study revealed the mechanism of gut microbiota formation during infancy in an Asian elephant and provides important insights into the health control of Asian elephants in zoos
Detection of Lung Cancer Cells in Solutions Using a Terahertz Chemical Microscope
Cancer genome analysis has recently attracted attention for personalized cancer treatment. In this treatment, evaluation of the ratio of cancer cells in a specimen tissue is essential for the precise analysis of the genome. Conventionally, the evaluation takes at least two days and depends on the skill of the pathologist. In our group, a terahertz chemical microscope (TCM) was developed to easily and quickly measure the number of cancer cells in a solution. In this study, an antibody was immobilized on a sensing plate using an avidin-biotin reaction to immobilize it for high density and to improve antibody alignment. In addition, as the detected terahertz signals vary depending on the sensitivity of the sensing plate, the sensitivity was evaluated using pH measurement. The result of the cancer cell detection was corrected using the result of pH measurement. These results indicate that a TCM is expected to be an excellent candidate for liquid biopsies in cancer diagnosis
Meson-baryon sigma terms in QCD Sum Rules
We evaluate the pion-nucleon and the pion-Delta sigma terms by employing the
method of quantum chromodynamics (QCD) sum rules. The obtained value of the
pion-nucleon sigma term is compatible with the larger values already
anticipated by the recent calculations. It is also found that the pion-Delta
sigma term is as large as the pion-nucleon sigma term.Comment: 14 pages, 2 figures; extended discussion and added references;
version to be published in Phys. Lett.
- …