118 research outputs found
Sharp lines in the absorption edge of EuTe and PbEuTe in high magnetic fields
The optical absorption spectra in the region of the \fd transition energies
of epitaxial layers of of EuTe and \PbEuTe, grown by molecular beam epitaxy,
were studied using circularly polarized light, in the Faraday configuration.
Under \sigmam polarization a sharp symmetric absorption line (full width at
half-maximum 0.041 eV) emerges at the low energy side of the band-edge
absorption, for magnetic fields intensities greater than 6 T. The absorption
line shows a huge red shift (35 meV/T) with increasing magnetic fields. The
peak position of the absorption line as a function of magnetic field is
dominated by the {\em d-f} exchange interaction of the excited electron and the
\Euion spins in the lattice. The {\em d-f} exchange interaction energy was
estimated to be eV. In \PbEuTe the same absorption line
is detected, but it is broader, due to alloy disorder, indicating that the
excitation is localized within a finite radius. From a comparison of the
absorption spectra in EuTe and \PbEuTe the characteristic radius of the
excitation is estimated to be \AA.Comment: Journal of Physics: Condensed Matter (2004, at press
Studies on possibility for alleviation of lifestyle diseases by low-dose irradiation or radon inhalation
Our previous studies showed the possibility that activation of the antioxidative function alleviates various oxidative damages, which are related to lifestyle diseases. Results showed that, low-dose X-ray irradiation activated superoxide dismutase and inhibits oedema following ischaemia-reperfusion. To alleviate ischaemia-reperfusion injury with transplantation, the changes of the antioxidative function in liver graft using low-dose X-ray irradiation immediately after exenteration were examined. Results showed that liver grafts activate the antioxidative function as a result of irradiation. In addition, radon inhalation enhances the antioxidative function in some organs, and alleviates alcohol-induced oxidative damage of mouse liver. Moreover, in order to determine the most effective condition of radon inhalation, mice inhaled radon before or after carbon tetrachloride (CCl4) administration. Results showed that radon inhalation alleviates CCl4-induced hepatopathy, especially prior inhalation. It is highly possible that adequate activation of antioxidative functions induced by low-dose irradiation can contribute to preventing or reducing oxidative damages, which are related to lifestyle diseases
Characteristic of double-stator PM machine for modular type power train in electric vehicles
This paper presents a double-stator permanent magnet brushless DC machine (DS-PMBLDC) which is proposed to be used in light electric vehicles and to replace a typical motor for electric vehicles in future. However, to fulfill the limitation of motor performance at different conditions, electric vehicles require their own specific motor design. Thus, a modular type of motor which can easily replace the electrical motor based on requirements for the electric driving system in power train of an electric vehicle was proposed and discussed in this paper. The operating principle of the proposed machine is reported. Concentrated winding is adopted for the stators of a 9-slot 8-pole DS-PMBLDC machine. The cogging torque, back-EMF, air-gap flux density, torque and power characteristic have been analyzed using 2-dimensional Finite-Element Analysis (2D-FEA). Experimental and simulation results are compared and discussed. Theoretical analysis of the proposed machine show an efficiency of 80% and 75% efficiency in motoring and generating mode respectively. The 2D-FEA simulation results are in good agreement with the measurement results
Comparative Study on the Inhibitory Effects of α-Tocopherol and Radon on Carbon Tetrachloride-Induced Renal Damage
Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone’s attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl4)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl4 after inhaling approximately 1000 or 2000 Bq/m3 radon for 24 h, or immediately after i.p. injection of α-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m3 has the inhibitory effects similar to α-tocopherol treatment at a dose of 300–500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl4 alone. These findings suggest that radon inhalation has an antioxidative effect against CCl4-induced renal damage similar to the antioxidative effects of α-tocopherol due to induction of antioxidative functions
Dysregulated expression of MIG/CXCL9, IP-10/CXCL10 and CXCL16 and their receptors in systemic sclerosis
Abstract
Introduction
Systemic sclerosis (SSc) is characterized by fibrosis and microvascular abnormalities including dysregulated angiogenesis. Chemokines, in addition to their chemoattractant properties, have the ability to modulate angiogenesis. Chemokines lacking the enzyme-linked receptor (ELR) motif, such as monokine induced by interferon-γ (IFN-γ) (MIG/CXCL9) and IFN-inducible protein 10 (IP-10/CXCL10), inhibit angiogenesis by binding CXCR3. In addition, CXCL16 promotes angiogenesis by binding its unique receptor CXCR6. In this study, we determined the expression of these chemokines and receptors in SSc skin and serum.
Methods
Immunohistology and enzyme-linked immunosorbent assays (ELISAs) were used to determine chemokine and chemokine receptor expression in the skin and serum, respectively, of SSc and normal patients. Endothelial cells (ECs) were isolated from SSc skin biopsies and chemokine and chemokine receptor expression was determined by quantitative PCR and immunofluorescence staining.
Results
Antiangiogenic IP-10/CXCL10 and MIG/CXCL9 were elevated in SSc serum and highly expressed in SSc skin. However, CXCR3, the receptor for these chemokines, was decreased on ECs in SSc vs. normal skin. CXCL16 was elevated in SSc serum and increased in SSc patients with early disease, pulmonary arterial hypertension, and those that died during the 36 months of the study. In addition, its receptor CXCR6 was overexpressed on ECs in SSc skin. At the mRNA and protein levels, CXCR3 was decreased while CXCR6 was increased on SSc ECs vs. human microvascular endothelial cells (HMVECs).
Conclusions
These results show that while the expression of MIG/CXCL9 and IP-10/CXCL10 are elevated in SSc serum, the expression of CXCR3 is downregulated on SSc dermal ECs. In contrast, CXCL16 and CXCR6 are elevated in SSc serum and on SSc dermal ECs, respectively. In all, these findings suggest angiogenic chemokine receptor expression is likely regulated in an effort to promote angiogenesis in SSc skin.http://deepblue.lib.umich.edu/bitstream/2027.42/112894/1/13075_2010_Article_3001.pd
A line-based approach for precise extraction of road and curb region from mobile mapping data
Planar structure detection from point clouds is important process in many applications such as maintenance of infrastructure facility
including roads and curbs because most artificial structures consists of planar surfaces. The Mobile Mapping System can obtain a
large amount of points with traveling at a standard speed. However, in the case that the high-end laser scanning system is equipped,
the distribution density of points is uneven. In the point-based method, this situation causes the problem to the method of calculating
geometric information using neighborhood points. In this paper, we propose a line-based region growing method in order to detect
planar structures with precise boundary from point clouds with uneven distribution density of points. The precise boundary of a planar
structure is maintained by appropriately creating line segments from the input clouds. We adapt the definition of neighborhood and
the estimation of the normal vector to the line-based region growing. The evaluation by comparing our result with manually extracted
points shows that more than 98% of curb points are detected. And, about 90% of the boundary points between a road and a curb are
detected with less than 0.005 meters of the distance error
Study of matrix converter based unified power flow controller applied PI-D controller
In this paper, the Unified Power Flow Controller (UPFC) using a matrix converter is studied. It is an adaptation of an approximate differentiation type PI-D controller. By setting appropriately the values of the gain controller, it is possible to stabilise the power of the transmission line by controlling the UPFC by a matrix converter. The matrix converter is a power conversion circuit that can convert an
arbitrary phase and amplitude of the AC power directly to AC power. The principle of creating a switching pattern that adopts a Direct Duty ratio Pulse Width Modulation (DDPWM) scheme. The UPFC is a stationary device to adjust
the grid voltage for controlling the power flow is inserted into the power system, and controls the transmission power according to the load variations. This is intended to stabilise the power system. Verification is done by simulation using MATLAB/Simulink for the validity of this proposed method
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