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排序方式: 共有318条查询结果,搜索用时 31 毫秒
121.
K Nitta K Uchida N Kimata A Kawashima W Yumura H Nihei 《Canadian Metallurgical Quarterly》1995,293(4):491-494
These experiments were performed in an attempt to determine whether chronic stimulation of glomerular endothelial cells with recombinant human erythropoietin would alter mesangial cell proliferation. Glomerular endothelial cells in culture incubated with various concentrations of erythropoietin for up to 4 days exhibited dose-dependent endothelin-1 production. Moreover, the conditioned medium from erythropoietin-stimulated glomerular endothelial cells enhanced [3H]thymidine incorporation into mesangial cells. This enhancement was significantly attenuated in the presence of a endothelin A receptor antagonist, BQ-123. These results suggest that endothelin-1 mediates erythropoietin-stimulated glomerular endothelial cell-dependent mesangial cell proliferation, resulting in the progression of glomerulonephritis. 相似文献
122.
H Hirabayashi H Hamano Y Ohnuki M Nitta Y Shinohara 《Canadian Metallurgical Quarterly》1997,37(10):937-939
We report a 56-year-old female with chronic progressive sensory ataxic neuropathy presenting with alternating skew deviation on lateral gaze in the clinical course. She initially developed dysesthesias in the hands and feet asymmetrically, then gait disturbance developed over several months, and she was admitted to our hospital. Neurological examinations revealed profound deep sensory loss and mild superficial sensory disturbance with the absence of deep tendon reflexes, but muscular strength was completely preserved. EMG showed no evoked response of sensory nerve velocities and normal motor nerves. Sural nerve biopsy showed moderate demyelination with mild infiltration of inflammatory cells, and no vasculitis or onion bulb formation. CSF examination revealed elevation of cell counts and protein with marked intrathecal IgG synthesis and myelin basic protein, but finding of neurosyphillis. Serological examinations did not show any evidence of collagen disease, paraproteinemia, retrovirus infections or Lyme disease. Serum antiganglioside antibodies and anti-Hu antibody were negative. No evidence of malignancy was seen by radiological examinations and assays of tumor markers. In the weeks after admission, gait ataxia progressively worsened, and then she developed alternating skew deviation on lateral gaze, suggesting that the CNS was involved. No responsible lesion was detected on MRI. Corticosteroid administration improved not only the CSF findings, but also the neurologic symptoms, including the alternating skew deviation on lateral gaze. Although the disease entity was not identified, inflammatory demyelinating processes and immune-mediated mechanisms were considered to play important roles. 相似文献
123.
B.N. Kalinin A.P. Potylitsin V.A. Verzilov I.E. Vnukov I. Endo M. Harada T. Kobayashi T. Kuwamoto K. Yoshida M. Muto H. Nitta 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1994,350(3):601-604
The effect of the beam divergence on the parametric X-radiation has been experimentally investigated at NPI, Tomsk, and at INS, Tokyo for the electron energies 600 and 800 MeV, respectively. It has been shown that the crystal-orientation dependence of PXR is sensitive to the beam divergence, suggesting that PXR can offer a simple means for determining the angular divergence of high energy charged particle beams. 相似文献
124.
Tamihiro Gotoh Shuichi Nonomura Satoshi Hirata Naotsugu Masui Shoji Nitta 《Solar Energy Materials & Solar Cells》1997,49(1-4)
The light- and thermal-induced changes of Si---H bonds in undoped a-Si : H have been studied on the infrared absorption of Si---H stretching mode, using the infrared photothermal deflection spectroscopy and the photothermal bending spectroscopy. The results show that the IR absorption of Si---H bonds increases by light soaking of the high power 500 mW/cm2. The change of IR absorption of Si---H bonds reoccurs by thermal annealing at 200°C. This change is related to the increase of the dangling bonds under light soaking. Furthermore, we observe the change of the elasticity modulus by light soaking, using the photothermal bending spectroscopy. The structural change in a-Si : H is discussed based on these results. 相似文献
125.
Hiroyuki Hatta Tanzo Nitta Yasuyuki Shirai Kazuhiro Fujikawa 《Electrical Engineering in Japan》2002,141(3):30-38
Superconducting fault current limiters (SCFCLs) are expected to improve not only reliability but also stability of power systems. To introduce an SCFCL in a power system, various specifications such as trigger current level, impedance in current limiting operation, recovery time, and so on are necessary. Fault analyses point out that accuracy of the trigger current level is necessary. Therefore, an SCFCL of a transformer type with adjustable trigger current level was proposed and manufactured. Using the trial SCFCL, adjustability of the trigger current level was confirmed. It is found that the SCFCL has good limiting and recovery characteristics. In this paper, characteristics of the SCFCL are considered from a design point of view. Most of the specifications necessary for design depend on the characteristics in current limiting operation. Therefore, the characteristics of the SCFCL in current limiting operation are discussed. It is shown that this kind of SCFCL has good property for easy design, and its design principle is summarized. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(3): 30–38, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10054 相似文献
126.
The atmospheric concentration and dry and wet deposition were measured for particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) from August to December in Higashi-Hiroshima City, Japan. PM concentration of fine particles (0.6-7 microm) was 5.7-75.1 micro m(-3), and coarse particles (> 7 microm) was 2.2-22.3 microg m(-3). Total PAHs concentration of fine particles was 0.14-16.3 ng m(-3), and coarse particles was 0.01-0.77 ng m(-3). Their concentration increased on non-rainy days and decreased rapidly on rainy days. For seasonal fluctuations of PAHs, their concentrations decreased from summer to winter, and the rate of decrease was more distinct for fine particles. For total (dry + wet) depositions, the PM flux was 1.9-11.2 mg m(-2) d(-1), and the total PAHs flux was 1.9-97.2 ng m(-3) d(-1). From these measurements, the yearly total loading of PAHs was estimated for the particle phase. Total loading was 28 microg m(-2) y(-1) for the dry deposition and 52 mg m(-2) y(-1) for the wet deposition. The loading of the wet deposition was comparable to those of the dry deposition for all ring numbers. 相似文献
127.
T Yambe S Kobayashi S Nanka M Yoshizawa K Tabayashi H Takeda S Nitta 《Canadian Metallurgical Quarterly》1998,21(6):348-352
The aim of this study was to compare the clinical efficacy and safety of low dose cyproterone acetate-estrogen combination (Diane) and the 5 alpha-reductase inhibitor finasteride in the treatment of hirsutism. Fourty-two women with hirsutism were included in the study. Twenty-one patients treated with cyproterone acetate (CPA) 2 mg and ethinyl estradiol (E) 35 micrograms daily on days 5-25 of the menstrual cycle, 21 with finasteride 5 mg daily. Hirsutism score, hormone levels, multiscreen blood chemistry and side effects were evaluated at three-monthly intervals for 9 months. A significant decrease in hirsutism score as compared to baseline was observed after 9 months with either CPA + E (Diane) (mean +/- SE, 15.81 +/- 1.19 vs 8.38 +/- 1.21) or finasteride treatment (17.81 +/- 1.05 vs 10.86 +/- 0.91) (p < 0.0005). The reductions in hirsutism scores (mean% +/- SE) were 14.23 +/- 2.29 vs 19.77 +/- 2.22 (p < 0.05) at 3, 40.23 +/- 4.58 vs 29.49 +/- 2.69 (p < 0.02) at 6 and 50.99 +/- 4.13 vs 39.87 +/- 3.30 (p < 0.02) at 9 months in CPA + E and finasteride groups, respectively. No significant changes were observed in hormone levels during finasteride treatment. Serum free testosterone significantly decreased at the third month of treatment, and remained suppressed for the duration of treatment in CPA + E group. DHEAS levels also decreased significantly after 6 and 9 months of therapy with CPA + E. SHBG significantly increased during CPA + E treatment. We conclude that both drugs are effective and well tolerated, but CPA + E appears to be more effective than 5 alpha-reductase inhibitor finasteride in long-term treatment of hirsute women. Diane is also a cost-effective drug. 相似文献
128.
S. Tsukimoto K. Nitta T. Sakai M. Moriyama Masanori Murakami 《Journal of Electronic Materials》2004,33(5):460-466
In order to understand a mechanism of TiAl-based ohmic contact formation for p-type 4H-SiC, the electrical properties and
microstructures of Ti/Al and Ni/Ti/Al contacts, which provided the specific contact resistances of approximately 2×10−5 Ω-cm2 and 7×10−5 Ω-cm2 after annealing at 1000°C and 800°C, respectively, were investigated using x-ray diffraction (XRD) and high-resolution transmission
electron microscopy (HRTEM). Ternary Ti3SiC2 carbide layers were observed to grow on the SiC surfaces in both the Ti/Al and the Ni/Ti/Al contacts when the contacts yielded
low resistance. The Ti3SiC2 carbide layers with hexagonal structures had an epitaxial orientation relationship with the 4H-SiC substrates. The (0001)-oriented
terraces were observed periodically at the interfaces between the carbide layers and the SiC, and the terraces were atomically
flat. We believed the Ti3SiC2 carbide layers primarily reduced the high Schottky barrier height at the contact metal/p-SiC interface down to about 0.3
eV, and, thus, low contact resistances were obtained for p-type TiAl-based ohmic contacts. 相似文献
129.
Summary Mechanical properties of polycyclo-olefins (PCOs) were investigated in the vicinity of the glass transition temperature (Tg). According to tensile tests, the fracture modes of PCOs such as brittle, ductile, and impact processes were largely dependent
on the elongation speeds below Tg. In addition, the stress-strain curves were found to be superimposed by the shift factors on transverse and longitudinal
axes, giving a typical master curve for tensile fracture behavior. 相似文献
130.
Three-dimensional shift selectivity of a reflection-type hologram with speckle shift recording is investigated experimentally and numerically. We build an experimental setup consisting of lenses with numerical apertures of 0.28 and an iron-doped LiNbO(3) with a thickness of 0.5 mm. The experimental results show that three-dimensional selectivity has a size of 0.97 microm x 0.97 microm x 8.8 microm in diffraction efficiency. We also develop a volume holographic memory simulator to evaluate the experimental results. The simulator can quantitatively evaluate bit error rate, signal-to-noise ratio, and diffraction efficiency. Numerical results are in good agreement with the experimental results. The experimental and numerical results indicate that three-dimensional shift multiplexing can increase the storage capacity. 相似文献