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41.
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S Ohue K Kohno K Kusunoki K Sadamoto S Ohta T Ueda S Sakaki 《Canadian Metallurgical Quarterly》1998,40(8):536-540
Although magnetic resonance angiography (MRA) is accepted for showing chronic intracranial stenotic or occlusive lesions, the method has not been practically examined in patients with acute cerebral ischaemia. We carried out three-dimensional time-of-flight MRA in six patients with acute ischaemia treated by local thrombolysis, and compared the findings with those of digital subtraction angiography (DSA). In all patients, MRA before thrombolysis clearly demonstrated the occluded arteries, which corresponded precisely to those shown by DSA. In four patients with complete recanalisation of the occluded vessels after thrombolysis, the recanalisation could be demonstrated by postoperative MRA. In one patient with reocclusion of the recanalised artery, repeat MRA also demonstrated the reocclusion, confirmed by DSA. These results suggest that MRA may be helpful for noninvasive investigation before and after thrombolysis. 相似文献
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Ultra wideband antennas are specifically designed to transmit and/or receive very short time durations of electromagnetic energy. It is well known that UWB antenna design remains the major factor in the progress of UWB technology. This article describes a study of conventional antennas and why they are not suitable for a UWB system. 相似文献
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Two breast cancer cell lines, YMB-S and ZR-75-1S, were established in our laboratory. They proliferated in suspension culture without aggregation in a complete liquid medium. We found that sodium butyrate (NaB) arrested the cells in the G0-G1 phase of the cell cycle, inhibited their proliferation, and induced cell-cell and cell-surface adhesion. In this study, we explored the mechanism of this adhesion. Adhesion was inhibited by an anti-E-cadherin antibody, suggesting a role for E-cadherin. However, there were no changes in the expression of E-cadherin, alpha-catenin, and beta-catenin. Northern blot analysis and cytofluorometry revealed that NaB-treated cells showed a lower expression of MUC1 than did untreated cells. To examine the possibility that the adhesion of these cells might be induced by decreased MUC1 expression, the level of MUCI expression was directly reduced using an antisense oligonucleotide. The MUC1 antisense oligonucleotide induced cell-cell and cell-surface adhesion of these breast cancer cells, just as NaB did. Our observations indicate that E-cadherin can be functionally suppressed by overexpression of MUC1 but resumes its activity after suppression of MUC1 expression. Thus, regulation of MUC1 might be a new strategy for cancer therapy. 相似文献
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This paper proposes a wireless multimedia code division multiple access (CDMA) system based on transmission power control. When we transmit multimedia information (i.e., speech, image, and data), differences in information rate, traffic performance, and required quality should be taken into account. The wireless CDMA system can achieve a flexible balance if transmission power distribution is controlled by using channel measurement information, i.e., traffic. In this paper, the optimal control of transmission power is derived by linear programming and nonlinear programming. Numerical results using a LAN demonstrate that the proposed method can satisfy the required quality 相似文献
49.
S Nishibayashi M Asanuma M Kohno M Gómez-Vargas N Ogawa 《Canadian Metallurgical Quarterly》1996,67(5):2208-2211
It has recently been considered that free radicals are closely involved in the pathogenesis of Parkinson's disease (PD), and the level of nitric oxide radical (.NO), one of the free radicals, is reported to increase in PD brain. In the present study, we established a direct detection system for .NO in an in vitro .NO-generating system using 3-(2-hydroxy-1-methylethyl-2-nitrosohydrazino)-N-methyl-1-propa namine as an .NO donor and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO) by electron spin resonance (ESR) spectrometry and examined the quenching effects of the dopamine agonists pergolide and bromocriptine on the amount of.NO generated. .NO appeared to be scavenged by pergolide and, to a lesser extent, by bromocriptine. In the competition assay, the 50% inhibitory concentration values for pergolide and bromocriptine were estimated to be approximately 23 and 200 microM, respectively. It was previously reported that in vivo treatment of pergolide and bromocriptine completely protected against the decrease in levels of striatal dopamine and its metabolites in the 6-hydroxydopamine-injected mouse. Considering these findings, pergolide and probably bromocriptine may also protect against dysfunction of dopaminergic neurons because of its multiple effects; not only does it stimulate the presynaptic autoreceptors, but it also directly scavenges .NO radicals and hence protects against .NO-related cytotoxicity. This ESR spectrometry method using carboxy-PTIO may be useful for screening other drugs that can quench .NO. 相似文献
50.
Morimoto M. Orihara K. Mutoh N. Toyoda A. Ohbo M. Kawakami Y. Nakano T. Chiba K. Kawai S. Hatano K. Arai K. Nishimura M. Nakashiba Y. Kohno A. Akiyama I. Teranishi N. Hokari Y. 《Electron Devices, IEEE Transactions on》1995,42(1):50-57
A 1-inch 2-million pixel FIT-CCD image sensor for HDTV has been developed, which features a tungsten photo-shield and horizontal CCD (H-CCD) shunt wiring. Tungsten photo-shield, which has low reflectance and good step coverage characteristics, reduces smear level to -110 dB, combined with a frame-interline-transfer (FIT) scheme. The tungsten photo-shield also acts as a shunt busline, supplying transfer pulses to vertical CCD (V-CCD) electrodes, so that a 1.2×10ˆ5 electron charge handling capability is obtained at a frame transfer frequency of 1 MHz. Newly developed H-CCD shunt wiring suppresses vertical line pair FPN, even with smaller transfer pulse amplitudes. H-CCD shunt wiring also helps reduce power consumption in the H-CCD by 2/3 as compared to that achieved with conventional wiring 相似文献