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811.
Inspection of passivated microdevices using the scanning electron microscope (SEM) at a low primary electron energy has been increasingly studied. Previously we reported an empirical formula for conditions under which SEM observations over the passivation layer can be made without inducing serious charging disturbances. An investigation of charge balance between primary and secondary electrons was presented. The present work investigates the charging disturbance-free conditions of PSG, SiN, and Si3N4 passivated devices and how they are affected by beam irradiation. The storage time of the voltage contrast is measured for various values of primary electron energy and incident angle. 相似文献
812.
H Taniguchi H Koyama M Masuyama A Takada T Mugitani H Tanaka M Hoshima T Takahashi 《Canadian Metallurgical Quarterly》1996,37(9):1522-1523
We quantitatively measured blood flow in liver parenchyma and hepatic tumors in two patients using 15O-carbon dioxide (steady state) and 15O-water (dynamic) PET imaging. Images were acquired before and during administration of angiotensin-II to achieve a hypertensive state. Blood flow in the hepatocellular carcinoma was greater than that of the parenchyma. Blood flow in the colon metastasis was similar to that in the parenchyma and lower in the center than in the periphery. During a hypertensive state induced by angiotensin II, blood flow in both the primary and secondary liver tumors did not change, while blood flow in the liver parenchyma decreased. As a result, there was a relative increase in tumor blood flow during the hypertensive state on PET images. Furthermore, blood flow to the spleen decreased to 55% of baseline during the hypertensive state. These findings suggest that hypertensive cancer chemotherapy may protect normal tissue. Furthermore, PET imaging may be able to predict the efficacy of hypertensive cancer chemotherapy in the patients with liver tumors. 相似文献
813.
Using microiontophoresis on unanesthetized head-restrained cats, we have found two distinct groups of neurones exhibiting tonic discharge specific to paradoxical sleep (PS) (PS-on neurones) in the mesopontine tegmentum, which contains both cholinergic and non-cholinergic neurones. One group is characterized by a broad action potential, slow conduction velocity and an inhibitory response to a potent cholinergic agonist, carbachol, applied iontophoretically during PS. The other is characterized by a short action potential, fast conduction velocity and an excitatory response to applied carbachol. All PS-on neurones were excited by glutamate. The present findings demonstrate the existence of two types of PS-on neurones and suggest their cholinergic and noncholinergic neurochemical properties. 相似文献
814.
X. J. Liu I. Ohnuma C. P. Wang M. Jiang R. Kainuma K. Ishida M. Ode T. Koyama H. Onodera T. Suzuki 《Journal of Electronic Materials》2003,32(11):1265-1272
Recent progress on the thermodynamic databases of calculated phase diagrams in microsolders and Cu-based alloys is presented.
A thermodynamic tool, Alloy Database for Microsolders (ADAMIS), is based on comprehensive experimental and thermodynamic data
accumulated with the calculation of phase diagrams (CALPHAD) method and contains eight elements, namely, Ag, Bi, Cu, In, Sb,
Sn, Zn, and Pb. It can handle all combinations of these elements and all composition ranges. The elements of Al and Au have
also been added to ADAMIS within a limited range of compositions. Furthermore, a database of Cu-based alloys, including binary
(Cu-X), ternary (Cu-Fe-X, Cu-Ni-X, and Cu-Cr-X), and multicomponent (Cu-Ni-Cr-Sn-Zn-Fe-Si) systems, has also been developed.
Typical examples of the calculation and application of these data-bases are presented. These databases are expected to be
a powerful tool for the development of Pb-free solders and Cu substrate materials as well as for promoting the understanding
of the interfacial phenomena between them in electronic packaging technology. 相似文献
815.
816.
M Hoshiyama R Kakigi S Koyama S Watanabe M Shimojo 《Canadian Metallurgical Quarterly》1997,10(1):23-30
The cyclin-dependent kinase (Cdk) inhibitor p21Waf1/Cip1/Sdi1, important for p53 tumor suppressor-dependent cell growth control in humans and other organisms, mediates G1/S-phase arrest through inhibition of cyclin-dependent kinases (Cdks). The enzymatic activity of these kinases is essential for progress through the cell division cycle and one level of cell cycle regulation is exerted through inhibition of Cdks by a family of small proteins, including p21. Cdk inhibition requires a sequence of approximately 60 amino acids within the p21 NH2-terminus. Using proteolytic mapping, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, HPLC and size-exclusion chromatography, we show that p21, active as a Cdk inhibitor, exists in an extended, non-globular conformation in the absence of its biological target and that p21 lacks the hallmarks of stable secondary and tertiary structure. We have developed an efficient approach to obtain detailed proteolytic maps that takes advantage of the high accuracy and sensitivity of MALDI mass spectrometry. Our method allows a proteolytic map to be obtained from a single mass spectrum for fragments produced from a single proteolytic reaction. 相似文献
817.
Nishiyama N. Mizutani A. Hatori N. Arai M. Koyama F. Iga K. 《Photonics Technology Letters, IEEE》1998,10(12):1676-1678
We have demonstrated an oxide confinement vertical-cavity surface-emitting laser grown on a GaAs (311)B substrate, and achieved single-transverse mode and single-polarization operation in the entire tested current range. The threshold was 0.6 mA for a 2.7 μm×2.9 μm oxide aperture. Even under high-speed modulation up to 5 GHz, the device showed stable single-transverse mode and polarization. Sidemode suppression ratio and orthogonal polarization suppression ratio were over 30 and 10 dB, respectively 相似文献
818.
819.
M Koyama K Satoh H Yoshida S Suzuki H Koie S Takamatsu 《Canadian Metallurgical Quarterly》1996,76(4):610-614
Surface coverage with autogeneous endothelial cells is effective in reducing thrombogenicity of an artificial vascular graft, but procedure for obtaining the cells is invasive for patients. The purpose of this study was to establish cultures of human endothelial cells separated from a small piece of subcutaneous fat tissue. A piece of tissue weighing about 10 mg was obtained from subcutaneous fat using a biopsy needle, and treated with collagenase and dispase. Microvascular endothelial cells were selected and other types of cells contaminating the cultures were eliminated by scraping with a needle under a microscope. The yield of the cells was 8362 +/- 4264/10 mg of subcutaneous fat (n = 7). The cultures reached confluence in about 2 weeks. The cells were positive for von Willebrand factor, P-selectin, and uptake of acetylated low density lipoprotein. The cells produced 15.9 +/- 3.3 ng/mg cell protein/h of 6-ketoprostaglandin F1 alpha (n = 5) when stimulated with thrombin. Thrombin also stimulated the production of platelet-activating factor: 7653 +/- 4297 dpm/10(6) cells (n = 5). Endothelin-1 accumulation in the medium of unstimulated endothelial cells was 0.54 +/- 0.16 ng/mg cell protein/10 h (n = 8). As a preliminary experiment for graft seeding, the cells were also cultured on pieces of a gelatin-coated Dacron graft, and scanning electron microscopy revealed the surface coverage of the graft. We herein described about successful culture of human microvascular endothelial cells from subcutaneous fat tissue obtained using a biopsy needle. The cultured cells may be applicable to a seeded vascular graft. 相似文献
820.
K Hayashi M Nie K Imanishi K Yamabuki Y Koyama K Suma 《Canadian Metallurgical Quarterly》1996,49(9):750-753
A 69-year-old male of effusive-constrictive pericarditis with a symptom of right heart failure was reported. The patient underwent surgery, as the medical treatment had not been effective. Through median spritting, very thickened pericardium and calcified epicardium of the right atrium, the right ventricle and the left ventricle were resected as largely as possible. In the space between the pericardium and epicardium, there existed yellow and thick fluid of about 50 ml which was evacuated. After surgery hemodynamic improvement was observed and the patient experienced a smooth postoperative course. Although pathological examinations revealed no special findings except the increased activity of adenosine deaminase of the yellow and thick fluid, tuberculosis was mostly suspected as the cause of the disease. 相似文献