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排序方式: 共有1005条查询结果,搜索用时 31 毫秒
1.
S Noguchi M Sata H Suzuki K Ohba M Mizokami K Tanikawa 《Canadian Metallurgical Quarterly》1997,24(5):992-994
Chinese hamster lung fibroblast V79 cells have been widely used in studies of DNA damage and DNA repair. Since the p53 gene is involved in normal responses to DNA damage, we have analyzed the molecular genetics and functional status of p53 in V79 cells and primary Chinese hamster embryonic fibroblast (CHEF) cells. The coding product of the p53 gene in CHEF cells was 76 and 75% homologous to human and mouse p53 respectively, and was 95% homologous to the Syrian hamster cells. The V79 p53 sequence contained two point mutations located within a presumed DNA binding domain, as compared with the CHEF cells. Additional immunocytochemical and molecular studies confirmed that the p53 protein in V79 cells was mutated and nonfunctional. Our results indicate that caution should be used in interpreting studies of DNA damage, DNA repair and apoptosis in V79 cells. 相似文献
2.
A 4*4 directional coupler switch matrix is developed which uses, for the first time, the quantum confined Stark effect of InGaAlAs/InAlAs multiquantum well structures. The rearrangeable nonblocking 4*4 network with six 2*2 switches is shown to be perfectly functional with switching voltages between 5 and 6 V and crosstalk below -17 dB in all the operation states.<> 相似文献
3.
Takeshi Kondo Hiroyuki Ito Kazuhide Kusakabe Kazuhiro Ohkawa Kensuke Honda Yasuaki Einaga Akira Fujishima Takeshi Kawai 《Diamond and Related Materials》2008,17(1):48-54
The effect of CF4 plasma etching on diamond surfaces, with respect to treatment time, was investigated using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. SEM observations and Raman spectra indicated an increase in surface roughening on a scale of 10–20 nm, and an increase in crystal defect density was apparent with treatment time in the range of 10 s to 30 min. In contrast, alteration of the diamond surface terminations from oxygen to fluorine was found to be rather rapid, with saturation of the F/C atomic ratio estimated from XPS analysis after treatment durations of 1 min and more. The redox kinetics of Fe(CN)63−/4− was also found to be significantly modified after 10 s of CF4 plasma treatment. This behavior shows that C–F terminations predominantly affect the redox kinetics compared to the effect on the surface roughness and crystal defects. The double-layer capacitance (Cdl) of the electrolyte/CF4 plasma-treated boron-doped diamond interface was found to show a minimum value at 1 min of treatment. These results indicate that a short-duration CF4 plasma treatment is effective for the fabrication of fluorine-terminated diamond surfaces without undesirable surface damage. 相似文献
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6.
Sixiong Han Yasuaki Ichikawa 《International journal for numerical methods in engineering》1995,38(24):4081-4100
In this paper, a mathematical model is proposed for the problem of the scattering of plane waves in a three-dimensional cracked materials. Instead of obtaining closed-form solutions as in conventional theoretical analysis methods, this approach, called the Equivalent Nodal Force (ENF) method formulates the mechanical effects of cracks as an equivalent nodal force in a numerical procedure, and physically translates cracked material into an equivalent continuous one. Several mechanical relations between waves and cracks are evident from this method. Also the results of several numerical calculations are presented and these are compared with those obtained by the conventional methods. 相似文献
7.
Y. Ohshima H.S. Ahn M. Aoki S. Awa M. Fukushima H. Hayashii X.Q. Hu T.W. Hur S. Igarashi H. Ikeda H.C. Jeong K. Kaneyuki D.Y. Kim S.K. Kim A. Kuzmin M.H. Lee S. Noguchi A. Ochi H. Sagawa N. Sato N. Sugiyama K. Tamai T. Tanimori N. Toomi T.J. Wang K. Watanabe Y. Watanabe X.C. Zhong Y.C. Zhu 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1996,380(3):517-523
We studied the performance of a prototype electromagnetic calorimeter for the BELLE detector at the KEK proton synchrotron for an energy range of 0.25–3.5 GeV. The prototype consisted of an array of 6 × 5 CsI(Tl) crystals with 30 cm length (16.2 radiation lengths) and about 6 cm × 6 cm cross section. The scintillation light of each CsI(Tl) crystal was read out by two large-area PIN photodiodes and charge-sensitive preamplifiers attached at the rear face of the crystal. We measured the energy and position resolution for electrons and the e/π separation for two sets of matrix configurations: one corresponded to the center and the other to the edge of the barrel calorimeter. The overall performance measured by the test proves that the prototype calorimeter is satisfactory for the use in the BELLE detector. 相似文献
8.
Noguchi K. Nagata M. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2007,15(10):1101-1110
An on-chip multichannel waveform monitoring technique enhances built-in test and diagnostic capabilities of systems- on-a-chip (SoC) integration. The proposed multichannel monitor includes multiple probing front-end modules and a single shared waveform acquisition kernel that consists of an incremental variable step delay generator and an incremental reference voltage generator, featuring adaptive sample time generation for the operation of a target circuit and unidirectional waveform acquisition flow for area-efficient control. A 16-channel prototype in 0.18-mum CMOS technology demonstrated on-chip waveform acquisition at 40-ps and 200-muV resolutions. Combined on- and off-chip streamed-bit processing achieves background continuous waveform acquisition at 260 ms per single timing point for repetitive signals, while eliminating the integration of on-die high-capacity memory. A 700 mum times 600 mum area was occupied by a waveform acquisition kernel and an additional 60 mum times 100 mum area for each front-end module. The developed on-chip multichannel waveform monitoring technique is waveform accurate, area efficient, and suitable for diagnosis toward power supply and signal integrity in analog and digital circuits in mixed-signal SoC integration. 相似文献
9.
Collinear magnetooptic interaction with magnetostatic surface waves (MSSW) can be used for wavelength‐selective switches, wavelength filters, and frequency shifters in wavelength‐division‐multiplexed (WDM) photonic networks and optical processing systems. The switching efficiency can be improved with a multilayer waveguide structure. To investigate the dynamic switching characteristics, the FDTD method was employed. The mode conversion between TE and TM mode was successfully demonstrated with FDTD simulation. The filtering characteristics were also evaluated. The FDTD results were compared with the result from the coupled mode theory, and good agreement was obtained. Switching of an optical pulse was also demonstrated by the FDTD method. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 40–47, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20501 相似文献
10.
The subcellular localization of Bcl-2 protein in surgically resected, fixed-frozen tissue specimens of seven tumors from six cases of synovial sarcoma and a synovial sarcoma cell line was examined using laser-scanning confocal microscopy and immunoelectron microscopy. Bcl-2 protein in synovial sarcoma cells was detected in the nuclear envelope, endoplasmic reticulum membrane, and mitochondrial circumference. Based on the finding of pre-embedding immunoelectron-microscopy observation, the distribution of Bcl-2 protein in such membranous organella was patchy. A computer-based image analysis failed to reveal any quantitative differences between the inner and the outer mitochondrial membranes. The tumorigenesis of synovial sarcoma is also discussed from the viewpoint of Bcl-2 overexpression. 相似文献