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排序方式: 共有500条查询结果,搜索用时 31 毫秒
21.
TA Kim J Lim S Ota S Raja R Rogers B Rivnay H Avraham S Avraham 《Canadian Metallurgical Quarterly》1998,141(3):553-566
The nuclear matrix is defined as the insoluble framework of the nucleus and has been implicated in the regulation of gene expression, the cell cycle, and nuclear structural integrity via linkage to intermediate filaments of the cytoskeleton. We have discovered a novel nuclear matrix protein, NRP/B (nuclear restricted protein/brain), which contains two major structural elements: a BTB domain-like structure in the predicted NH2 terminus, and a "kelch motif" in the predicted COOH-terminal domain. NRP/B mRNA (5.5 kb) is predominantly expressed in human fetal and adult brain with minor expression in kidney and pancreas. During mouse embryogenesis, NRP/B mRNA expression is upregulated in the nervous system. The NRP/B protein is expressed in rat primary hippocampal neurons, but not in primary astrocytes. NRP/B expression was upregulated during the differentiation of murine Neuro 2A and human SH-SY5Y neuroblastoma cells. Overexpression of NRP/B in these cells augmented neuronal process formation. Treatment with antisense NRP/B oligodeoxynucleotides inhibited the neurite development of rat primary hippocampal neurons as well as the neuronal process formation during neuronal differentiation of PC-12 cells. Since the hypophosphorylated form of retinoblastoma protein (p110(RB)) is found to be associated with the nuclear matrix and overexpression of p110(RB) induces neuronal differentiation, we investigated whether NRP/B is associated with p110(RB). Both in vivo and in vitro experiments demonstrate that NRP/B can be phosphorylated and can bind to the functionally active hypophosphorylated form of the p110(RB) during neuronal differentiation of SH-SY5Y neuroblastoma cells induced by retinoic acid. Our studies indicate that NRP/B is a novel nuclear matrix protein, specifically expressed in primary neurons, that interacts with p110(RB) and participates in the regulation of neuronal process formation. 相似文献
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We consider the energy saving problem for caches on a multi-core processor.In the previous research on low power processors,there are various methods to reduce power dissipation.Tag reduction is one of them.This paper extends the tag reduction technique on a single-core processor to a multi-core processor and investigates the potential of energy saving for multi-core processors.We formulate our approach as an equivalent problem which is to find an assignment of the whole instruction pages in the physical memory to a set of cores such that the tag-reduction conflicts for each core can be mostly avoided or reduced.We then propose three algorithms using different heuristics for this assignment problem.We provide convincing experimental results by collecting experimental data from a real operating system instead of the traditional way using a processor simulator that cannot simulate operating system functions and the full memory hierarchy.Experimental results show that our proposed algorithms can save total energy up to 83.93% on an 8-core processor and 76.16% on a 4-core processor in average compared to the one that the tag-reduction is not used for.They also significantly outperform the tag reduction based algorithm on a single-core processor. 相似文献
24.
Yan Liu Shigenori Mitsushima Ken-ichiro Ota Nobuyuki Kamiya 《Electrochimica acta》2006,51(28):6503-6509
The electro-oxidation of dimethyl ether (DME) on PtMe/Cs (Me = Ru, Sn, Mo, Cr, Ni, Co, and W) and Pt/C electro-catalysts were investigated in an aqueous half-cell, and compared to the methanol oxidation. The addition of a second metal enhanced the tolerance of Pt to the poisonous species during the DME oxidation reaction (DOR). The PtRu/C electro-catalyst showed the best electro-catalytic activity and the highest tolerance to the poisonous species in the low over-potential range (<0.55 V, 50 °C) among the binary electro-catalysts and the Pt/C, but at the higher potential (>ca. 0.55 V, 50 °C), the Pt/C behaved better than PtRu/C. The apparent activation energy for the DOR decreased in the order: PtRu/C (57 kJ mol−1) > Pt3Sn/C (48 kJ mol−1) ≈ Pt/C (46 kJ mol−1). On the other hand, the activation energy for the MOR showed a different turn, decreased in the following order: Pt/C (43 kJ mol−1) > Pt3Sn/C (35 kJ mol−1) ≈ PtRu/C (34 kJ mol−1). The temperature dependence of the DOR was greater than that of the oxidation of methanol (MOR) on the PtRu/C. 相似文献
25.
Maruo K. Tsurugi M. Chin J. Ota T. Arimoto H. Yamada Y. Tamura M. Ishii M. Ozaki Y. 《IEEE journal of selected topics in quantum electronics》2003,9(2):322-330
This paper reports in vivo near-infrared (NIR) noninvasive blood glucose assay using dermis tissue spectra. We assume that the glucose content in dermis tissue traces the variations in blood glucose. For dermis spectra measurements, epidermis, especially stratum corneum, acts as an interference in skin tissue. Thus, we have developed a method for the selective measurement of dermis tissue spectra, enabling us to obtain better quality spectra for an accurate blood glucose assay. The selective measurement of the dermis spectra realized by using a newly developed fiber-optic probe that consists of source and detector optical fibers separated by 0.65 mm on a skin surface. The light path in the skin tissue for this geometry has been simulated by a Monte Carlo method. The simulation results show that detected light mainly interrogates dermis tissue. As the absorbance signal of glucose in human tissue is extremely small, the quality of the measured spectra is critical for the reliable assay. The present method for blood glucose assay has been applied to one Type 1 diabetic. The correlation coefficient between the blood glucose content predicted by NIR spectra and those measured by finger-prick was 0.928 and the standard error of prediction was 32.2 mg/dL. These results demonstrate the potential of our methodology for noninvasive NIR blood glucose assay. 相似文献
26.
Multirobot motion coordination in space and time 总被引:5,自引:0,他引:5
Carlo Ferrari Enrico Pagello Jun Ota Tamio Arai 《Robotics and Autonomous Systems》1998,25(3-4):219-229
This paper describes a solution to the multirobot motion planning problem based on a decoupled analysis in the space domain and in the time domain. It investigates the practical use of the notion of motion plan quality and of the motion plan robustness measures for computing safe motions. The use of anytime algorithms allows one to evaluate the opportunity of looking for alternative solution paths by generating small variations of robot motions affecting both its geometrical path and its scheduled velocity. By using the concept of plan robustness, several alternative paths are generated and evaluated through various performance indices and impact factors, using heuristic rules. These indices allow one to know how much a variation affects a given plan. Finally, some recent experiments are outlined. 相似文献
27.
The 3D laser-interferometric CT measurement of the unsteady flow field induced by shock wave discharging from a circular nozzle next to a short columnar object in a shock tube experiment is presented as an extension of previous work of 3D measurement of open flow field. The 3D density distribution around the object is reconstructed with FBP (filtered back projection) and MLEM (maximum likelihood expectation maximization) algorithm from the incomplete projection data caused by the obstruction of the observation light for interferometry with an object in a test section. The 3D density-gradient distributions are also evaluated from the resultant 3D density distribution, we demonstrate that laser-interferometric CT measurement of interaction field of shock waves and an object come to sight. 相似文献
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29.
Yoshiaki Kinemuchi Ken-ichi Mimura Atsuya Towata Kazumi Kato 《Journal of Electronic Materials》2014,43(6):2011-2016
A giant Seebeck coefficient of ?890 μV/K at 500 °C has been observed in Y0.2Sr0.8TiO3 prepared using nanocubes. Doping rare earth elements, RE, has revealed that small RE is effective to enhance the Seebeck coefficient. Through soft mode observations by Raman spectroscopy and structural calculations based on density functional theory, it has been found that the breakdown of inversion symmetry of the perovskite structure near the surface of nanocubes can be recovered by doping with small RE. Because the dielectric constant is strongly related to the surface structure in this compound, we suggest that RE doping modulates the potential barrier at the grain boundary, resulting in a pronounced energy filtering effect in Y doped SrTiO3. 相似文献
30.