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951.
The structural requirement has been studied for apolipoproteins in their free form to interact with cells, to generate high
density lipoprotein (HDL), and to cause cellular lipid efflux (J. Biol. Chem. 266, 3080–3086, 1991). It is shown that human apolipoprotein (apo) A-IV and apolipophorin III ofManduca sexta cause cholesterol efflux from cholesterol-loaded mouse peritoneal macrophages and reduce intracellularly accumulated cholesteryl
ester as a results of forming HDL-like particles with cellular lipids, as do apoA-I, A-II and E. On the other hand, similar
to apoC-III, reduced-and-carboxymethylated human apoA-II had no such effect. Thus, apolipoproteins seem to require at least
four amphiphilic helical segments per molecule to express this function. 相似文献
952.
Osamu Ohtaka Takamitsu Yamanaka Shoichi Kume† Naoki Hara Hajime Asano Fujio Izumi 《Journal of the American Ceramic Society》1995,78(1):233-237
The crystal structure of orthorhombic HfO2 synthesized at 600°C and 6 GPa was investigated by a time-of-flight neutron powder diffraction experiment. Rietveld analysis of these data revealed that the space group of this phase is Pbca. The refined lattice parameters are a 0 = 1.00177, b 0 = 0.52276, and c 0 = 0.50599 nm. The structure is derived from a distorted fluorite (CaF2 ) structure by a b -glide parallel to the a -axis. The hafnium atom is in seven-fold coordination. The structure of orthorhombic HfO2 is found to be the same as that of an orthorhombic ZrO2 , which occurs under high pressure above 3 GPa. 相似文献
953.
Matsukawa T. Kishida A. Koh M. Hara K.-I. Horita K. Goto M. Matsuda S. Kuboyama S. Ohdomari I. 《Electron Device Letters, IEEE》1994,15(6):199-201
Soft-error sensitive junctions have been identified in a memory cell of a 63 kbit SRAM. The technique for hitting a micron-size area with a single ion enables us to get a soft-error map in a memory cell. A dependence of the maps on the supply voltage to the memory has been investigated. The errors due to the upset of an n-MOSFET have been observed at higher supply voltage than for a p-MOSFET. This result suggests that the n-MOSFET's are more error-sensitive than the p-MOSFET's for the reason that the n-MOSFET's have a higher efficiency of charge collection and a larger “on” current 相似文献
954.
Y Takeuchi K Sakurai I Ike H Yoshie K Kawasaki K Hara 《Canadian Metallurgical Quarterly》1995,30(6):426-435
Activated T lymphocytes constitute a major component of inflammatory cells in the early periodontal lesion, and also appear in the gingival crevicular fluid. In an attempt to clarify the relationship between the ICAM-1 (CD54) expression of pocket epithelium in gingiva and the infiltrating lymphocyte population, we carried out an analysis of CD11a+(LFA-1 alpha), CD25+(IL-2R alpha) and CD4+(Th) cells subjacent to ICAM-1-expressing pocket epithelia and CD11a+CD25+CD4+ cells in gingival crevicular fluid (GCF). GCF was collected by crevicular washing from 16 patients with periodontitis (P group) and 3 subjects with healthy gingiva (H group). Peripheral blood (PB) was collected at the same time. Mononuclear cells were isolated by Ficoll-paque gradient centrifugation from GCF and PB. Monoclonal antibodies (mAb) to CD11a, CD25, and CD4 were used for three-color flow cytometry. Gingival biopsies were obtained from 7 patients in P group and 3 subjects in H group. Serial cryostat sections (6 microns in thickness) were prepared from each biopsy, on which a double staining was performed. The number of CD11a+CD25+CD4+ cells and the fluorescence intensity of FITC conjugated anti-CD11a were significantly higher in GCF than in PB (p < 0.001 to p < 0.01). CD11a+CD25+CD4+ cells were not detected in GCF in H group. The pocket epithelia expressed CD54 in P group, but not in H group. The number of CD11a+, CD25+ and CD4+ cells infiltrating the connective tissue subjacent to the upper, middle and lower parts of the CD54 positive pocket epithelium (n = 16) was 141 +/- 26, 38 +/- 13, 144 +/- 29 (cells/0.04 mm2), respectively, whereas in the CD54 negative pocket epithelium, it was (n = 5) 9 +/- 2, 3 +/- 1, 8 +/- 3. In P group, the CD11a+CD25+CD4+ cell number in GCF correlated with CD25+, CD11a+ cells in the connective tissue subjacent to the CD54+ pocket epithelium. These results indicate that expression of ICAM-1 in pocket epithelium is relevant to the migration of CD11a, CD25, CD4 positive cells in connective tissue subjacent to the pocket epithelium into the periodontal pocket. Assessing the relationship of our findings and other adhesion molecules would offer important clues to the understanding of T cell migration in affected gingiva. 相似文献
955.
956.
N Tanaka T Nonaka M Nakanishi Y Deyashiki A Hara 《Canadian Metallurgical Quarterly》1995,118(5):871-873
Mouse lung carbonyl reductase (MLCR), which belongs to the short-chain dehydrogenase/reductase family, is an oxidoreductase involved in the metabolism of biogenic and xenobiotic carbonyl compounds. The crystals of MLCR complexed with its cofactor NADPH belong to a monoclinic space group P2(1) with dimensions a = 79.73 A, b = 105.5 A, c = 60.87 A, and beta = 91.43 degrees. X-ray diffraction data were collected up to 1.8 A resolution using a macromolecule-oriented Weissenberg camera at the Photon Factory synchrotron radiation source. Studies using a self-rotation function revealed the presence of a twofold rotational symmetry relating the subunits. This suggests that the tetrameric MLCR molecule has the 222 point group symmetry. 相似文献
957.
An analytical procedure to estimate both the natural frequencies and mode shapes of thin-walled members is presented using the transfer matrix method. The transfer matrix is derived from the differential equations of the plate panel of thin-walled members. The proposed method gives exact natural frequencies and mode shapes of thin-walled members. Thus the vibration phenomenon of such members can be clarified exactly. Some numerical examples are presented to illustrate the accuracy and efficiency of the proposed method. 相似文献
958.
H Niiro T Otsuka T Tanabe S Hara S Kuga Y Nemoto Y Tanaka H Nakashima S Kitajima M Abe 《Canadian Metallurgical Quarterly》1995,85(12):3736-3745
959.
A modified method for peroxide value (POV) determination of lipids was developed through the application of potentiometry
to conventional POV tests such as the official method of the Japan Oil Chemists’ Society (JOCS). The new method permits a
simple and reliable determination of low hydroperoxide levels in the initial stages of lipid autoxidation when only very small
amounts of sample are available, even when those levels are measured on less than 10 mg of lipid. Using the present method,
hydroperoxide levels as low as 20 nanoequivalents (neq) were determined with reasonable precision. This method is applicable
to all lipids tested including oils and fats, free fatty acids, phospholipids, glycolipids and cholesterol esters. 相似文献
960.
Shinsuke Hara Masutada Mouri Minoru Okada Norihiko Morinaga 《Wireless Personal Communications》1995,2(4):335-356
In this paper, we discuss the transmission performance of Multi-Carrier Modulation (MCM) in frequencyselective fast Rayleigh fading channels. First, we optimize the transmission parameters of MCM withM-ary differential phase shift keying/differential detection (DPSK):the guard duration andthe number of sub-carriers for frequency-selective fast Rayleigh fading channels, and then show the bit error rate (BER) performance of the optimizedM-ary DPSK MCM. Next, we propose an MCM with pilot-assistedM-ary quadrature amplitude modulation/coherent detection (QAM), and discuss the BER performance when we reduce the number of pilot signals from the view-point of frequency-time utilization efficiency. Finally, we propose a two-stage frequency offset compensation method. 相似文献