Antiestrogenic Activity of Extracts of Diesel Exhaust Particulate Matter in MCF-7 Human Breast Carcinoma Cells

Diesel exhaust particulate matter (DEP) was collected from three commercial diesel engine vehicles and DEP extracts (DEPEs) were prepared from each. The estrogenic and antiestrogenic activities of the DEPE samples were examined using an estrogen response element (ERE)-driven luciferase reporter gene assay in MCF-7 human breast cancer cells. While DEPE samples did not exhibit significant estrogen agonist activity alone, they suppressed 17 g -estradiol (E 2 )-induced luciferase activity without decreasing cell viability. Several polycyclic aromatic hydrocarbons (PAHs) acting as aryl hydrocarbon receptor (AhR) agonists were detected in the DEPEs and their concentrations were higher in DEPE samples with higher antiestrogenic activity. DEPE samples elevated cytochrome P450 (CYP) 1A1 activity. f -Naphthoflavone, an AhR antagonist, and SKF-525A, a nonselective CYP inhibitor, reversed and enhanced the antiestrogenic activity of DEPE samples, respectively. These results demonstrate that DEPE has antiestrogenic activity and this effect is primarily due to the PAH constituents acting as AhR agonists.     

Joint of silicon nitride and molybdenum with vanadium foil,and its high-temperature strength

Joints of silicon nitride and molybdenum with a vanadium interlayer were fabricated using a vacuum hot-pressing facility. The optimum joining conditions for producing a joint with the highest shear strength were found to be as follows: a temperature of 1328 K, a mechanical pressure of 20 MPa and a bonding time of 5.4 ks. The effect of test temperature on shear strength was also examined. The strength level was initially 118 MPa at room temperature and this level gradually decreased as the test temperature rose. At 973 K, the strength level was still 70 MPa. Observations of the interface by scanning electron microscopy (SEM) and electron probe X-ray microanalysis (EPMA) revealed that a layer of reaction product V₃Si formed at the silicon-nitride-vanadium interface.     

Backlight imaging tomography for slug flows in straight and helical tubes

Backlight imaging tomography is used to experimentally investigate interfacial structures of gas–liquid two-phase flow in circular tubes. The tomography method is based on the attenuation of visible light that causes the inside of the liquid phases to be colored with dye. Increasing the number of light projections provides accurate phase distributions to be reconstructed by a linear backward projection scheme. After the reconstruction performance is examined with numerical simulations for several test cases, the method is applied to slug flows that have complicated 3D interfaces from turbulence. Interfacial structures are compared between straight and helical tubes to determine the effect of centrifugal acceleration. The result demonstrates that centrifugal acceleration provides a liquid-clinging layer on the inner wall against gravity while a high-speed collision of liquid with the top wall happens in a straight tube.     

A calculation method of the total efficiency of wind generators

The spread of wind energy converters is progressing in recent years and its capacity is becoming larger and larger. In order to capture more energy from the wind, it is important to analyze loss characteristics of wind generators for the operating speed which is determined dependent on the wind speed. This paper presents a method to evaluate various losses in a wind generator as a function of wind speed, which is based on steady‐state analysis and thus the calculations can be performed quickly. By using the proposed method, wind turbine power, generator output, various losses, and the total energy efficiency are calculated for three types of wind speed data which are represented by a Weibull function. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(3): 52–62, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20426 Copyright © 2006 Wiley Periodicals, Inc.     

Cooperative operation of a wind energy conversion system with a hydrogen electrolyzer by using an adjustable speed flywheel generator

Hydrogen is considered as the energy source of the next generation. This paper proposes a system which consists of Flywheel Generator (FWG), Wind Energy Conversion System (WECS), and Hydrogen Electrolyzer (HE), for the purpose of hydrogen generation and grid output power smoothing. The cooperative control among flywheel generator, hydrogen electrolyzer, and wind generator is performed by controlling the flywheel generator. Simulations have been done by PSCAD/EMTDC. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(3): 19–27, 2009; Published online in Wiley InterScience ( www.interscience.wiley. com ). DOI 10.1002/eej.20863     

Hybrid Josephson Junctions with Iron-based and Conventional Superconductor Electrodes

We investigate the iron-based superconductor Ba(Fe _1?x Co _x ) ₂As ₂ (Ba-122) regarding its superconducting properties and possible applications. Therefore, Ba-122 thin films are used as base electrode to prepare different kinds of hybrid Josephson junctions with a counter electrode of the conventional superconductor Pb. Additionally, we use both c-axis and a b-plane transport geometries and different kinds of barriers like interface-engineered surfaces, sputtered titanium oxide and gold layers. Temperature dependent I– V characteristics as well as magnetic field dependence and microwave response of the junctions are shown. The examined I– V characteristics and I _c R _n– T behaviours of each junction type are compared and described according to the electrical behaviour of the respective normal conducting or insulating barrier. While the I _c R _n product of the interface-engineered barrier junction was 12 μV and the planar junction with Au barrier showed 18 μV, we could increase the I _c R _n to 90 μV for planar TiO _x barrier junctions.     

Comparison of three Chlamydomonas strains which show distinctive oxidative stress tolerance

Methyl viologen (MV) causes severe oxidative stress by generating superoxide in the photosystem. The marine Chlamydomonas strain W80 is highly tolerant to MV (inhibitory concentration 50% [IC??]=110 μM), and another marine Chlamydomonas strain HS5 shows also relatively a high tolerance (IC??=12 μM). These two marine strains and a freshwater Chlamydomonas reinhardtii, which is highly sensitive to MV (IC??=0.03 μM), were compared with respect to their reactive oxygen species (ROS) eliminating enzymes (superoxide dismutase, catalase, glutathione peroxidase, and ascorbate peroxidase), intracellular free amino acids, and antioxidant activities of the cell extracts. The marked difference between the marine Chlamydomonas strains and C. reinhardtii is the much higher (more than 5 fold) ascorbate peroxidase (APX) activity in the marine strains. The marine strains also kept the high APX activities (more than 100% of non-stressed condition) under the MV stressed condition, while the APX activity in C. reinhardtii was significantly decreased (36% of non-stressed condition) under the stressed condition, indicating that APX activity potentially contributes to the oxidative stress tolerance in Chlamydomonas. In addition, the levels of intracellular free proline, which is supposed to ameliorate oxidative stress, were several tens of times higher in the marine Chlamydomonas strains than in C. reinhardtii.     

Calculation of sudden three‐phase short‐circuit current of turbine generators by 3D magnetic field analysis

Sudden three‐phase short‐circuit current of a turbine generator was calculated by a three‐dimensional magnetic field analysis. That analysis takes into account the rotation, magnetic saturation, and eddy current at a rotor part. To compare test results and calculated results, a method was proposed for short‐circuit phase estimation at sudden three‐phase short‐circuit test by line voltage waveform of the test results. The calculated results of short‐circuit current waveform are in good agreement with the test results. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(1): 54–62, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20110     

Carbon KVV Auger electron emission from highly oriented pyrolytic graphite bombarded by fast protons

We have studied carbon KVV Auger electron emission from highly oriented pyrolytic graphite (HOPG) by ion-induced 180° electron spectroscopy. In obliquely emitting directions across the HOPG (0 0 0 1) surface, the Auger peak yield induced by MeV protons becomes lower than in the surface normal direction. An analysis based on mean free path for inelastic scattering indicates that the observed reduction of the Auger yield can be explained by increased inelastic collisions with valence electrons above the surface. The experimental results provide information about the production sites of the KVV Auger electrons in the layer structure.