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排序方式: 共有467条查询结果,搜索用时 46 毫秒
1.
Ken Kanazawa Shoji Yoshida Hidemi Shigekawa Shinji Kuroda 《Science and Technology of Advanced Materials》2015,16(1)
The reconstructed surface structure of the II–VI semiconductor ZnTe (110), which is a promising material in the research field of semiconductor spintronics, was studied by scanning tunneling microscopy/spectroscopy (STM/STS). First, the surface states formed by reconstruction by the charge transfer of dangling bond electrons from cationic Zn to anionic Te atoms, which are similar to those of IV and III–V semiconductors, were confirmed in real space. Secondly, oscillation in tunneling current between binary states, which is considered to reflect a conformational change in the topmost Zn–Te structure between the reconstructed and bulk-like ideal structures, was directly observed by STM. Third, using the technique of charge injection, a surface atomic structure was successfully fabricated, suggesting the possibility of atomic-scale manipulation of this widely applicable surface of ZnTe. 相似文献
2.
The effect of humidity during storage on the crosslinking reactions of isocyanate groups was investigated with attenuated total reflectance Fourier transform infrared spectroscopy with pressure‐sensitive adhesives composed of poly[ethyl acrylate‐co‐(2‐ethylhexyl acrylate)‐co‐(2‐hydroxyethyl methacrylate)] as a base resin and polyisocyanate as a crosslinker. A peak‐resolving analysis of the amide II region revealed four bands. According to an analysis of the Fourier transform infrared spectra of the model compounds, these four bands were assigned to free urethane linkages, hydrogen‐bonded urethane linkages, free urea linkages, and hydrogen‐bonded urea linkages. As expected, storage under humid conditions led to the formation of free and hydrogen‐bonded urea linkages corresponding to the promotion of isocyanate consumption. Peak resolution of the amide II region was found to be a reasonable way of monitoring urethane and urea linkages during crosslinking reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3039–3045, 2003 相似文献
3.
M Kanazawa M Yano C Namchai S Yamamoto A Ohtake M Takayanagi M Mori H Niimi 《Canadian Metallurgical Quarterly》1997,239(2):580-584
cDNAs for green fluorescent protein (GFP) and for a GFP fusion protein containing the presequence of human ornithine transcarbamylase (pOTC-GFP) were transfected into cultured human fibroblasts. GFP cDNA gave diffuse fluorescence throughout the cytoplasm and the nucleus, whereas pOTC-GFP cDNA gave mitochondria-associated fluorescence. Fluorescent mitochondrial structures could be classified into five patterns: thread-like mitochondria, fine thread-like ones, rod-like ones, granular ones, and granular ones with weak cytosolic fluorescence. pOTC-GFP mutants resulted in a loss of mitochondrial fluorescence and an appearance of weak fluorescence throughout the cytoplasm. pOTC-GFP cDNA was transfected into fibroblasts from patients with various mitochondrial diseases. Higher ratios of fibroblasts with granular mitochondria and those with fine thread-like ones were observed in a patient with Reye's syndrome and a patient with Kearns-Sayre syndrome. Weak cytosolic fluorescence was sometimes observed in fibroblasts from these patients. This method will be useful to analyze mitochondrial structural alterations and disorders of mitochondrial protein import. 相似文献
4.
Poly(L-ornithine)s having various azo-contents in the side chains were synthesized by the water-soluble carbodiimide procedure. The photochemical properties of the polypeptides poly[Nδ-p-(phenylazo)benzoyl-L-ornithine] (PPABLO) containing 3–77 mol% azobenzene were investigated by absorption and circular dichroism spectroscopy in hexafluoro-2-propanol (HFIP) or water, and in HFIP-water or methanol-water solvent mixtures. The photochromism of the dichroic bands of the PPABLOs containing 20–77 mol% azobenzene in the visible and ultraviolet wavelength regions was found to be mostly reversible as a function of irradiation time at different wavelengths due to the photostationary state (above 80% trans-cis photoisomerization) of the azo aromatic moieties. The PPABLO containing 3.2 mol% azobenzene in water exhibited conformational changes from random coil to helix by the addition of methanol or sodium dodecyl sulphate (SDS). The photo-induced conformational change was observed in HFIP-water-SDS solvent mixtures, while no conformational change was seen in water and HFIP-water solvent mixtures. 相似文献
5.
H Yasoshima K Uematsu K Sakurai Y Ueno K Hori N Kanazawa T Tanaka N Yamanaka E Okamoto 《Canadian Metallurgical Quarterly》1993,43(12):783-789
A case of primary carcinoid tumor arising in the liver of a 69 year old woman with no endocrine symptoms is reported. Histopathologically, the tumor was diagnosed initially as a hepatocellular carcinoma in the biopsy specimen, and was shown subsequently to be a carcinoid tumor, demonstrating diffuse positive staining with Grimelius method. Mucin stained with periodic acid-Schiff (PAS), alcian-blue, and mucicarmine, and was shown partially in the glandular structures. Immunohistochemically, most of the tumor cells stained positively for chromogranin-A, epithelial membrane antigen (EMA) and neuron specific enolase (NSE). Ultrastructural examination revealed electron-dense core granules, measuring 40-120 nm in diameter in some of the tumor cells. Intensive and careful searches pre- and post-operatively revealed no other primary source of tumor other than the liver. The patient was reported well with no symptoms 3 1/2 years after the operation. This case is considered to be a primary hepatic carcinoid tumor. The recent literature is reviewed, and the possible histogenesis of hepatic carcinoid tumor is discussed. 相似文献
6.
To elucidate whether dietary lipid peroxides are absorbed in the body, the catabolic fate of trilinoleoylglycerol hydroperoxides (TL-OOH), in the gastrointestines of rats was examined. Oxidized trilinoleoylglycerol with a peroxide value of 1000 meq/kg, 0.5 or 20 mg, was dosed intragastrically to rat together with 59.5 or 40 mg unoxidized trilinoleoylglycerol, respectively. The fate of TL-OOH in gastric and intestinal lumina was determined by high-performance liquid chromatography periodically until 240 min after treatment. At low dose, TL-OOH was soon broken down to linoleic acid hydroperoxides (LA-OOH) and hydroxyls, probably through gastric lipases, whereas at high dose, TL-OOH was retained in the stomach. In both cases, TL-OOH did not reach the intestines, though the unoxidized lipids moved to the intestines. When LA-OOH was given intragastrically, the lipids decomposed in the stomach, and linoleic acid hydroxyls, hexanal, 9-oxononanoic acid, and two novel compounds were detected 30 min after treatment. The novel compounds were identified to be epoxyketones, 11-oxo-12,13-epoxy-9- and 11-oxo-9,10-epoxy-12-octadecenoic acids. Thus, dietary TL-OOH was broken down in the stomach releasing, LA-OOH which decomposed further, and did not reach the intestines. 相似文献
7.
The trk gene family members; the neurotrophic receptors for neurotrophins, are implicated in the survival and the differentiation of neurons. The roles of these protooncogenes have been argued in the pathological conditions and in the specific developmental stage when the programmed cell death occurs to neurons. Here we studied a physiological role of the trk family members in the retina through observations of their gene regulation by light/darkness exposure. Northern blot analysis and immunohistochemistry demonstrate that trkB and trkC are up-regulated by light exposure and down-regulated by darkness in the rod/cone layer, the outer nuclear layer, and the ganglion cell layer. This physiological regulation suggests that these trk family members play a protective role from the damaging effect of light exposure in the retinal neurons. 相似文献
8.
Masayuki Nogami Yoshihiro Abe Ayako Kato 《Journal of the American Ceramic Society》1995,78(4):1066-1070
Silica glasses doped with small-sized CdSx -Se1-x crystals were prepared by the sol-gel method. Gels synthesized by the hydrolysis of Si(OC2 H5 )4 , in the presence of CdSeO4 with NH4 SCN dissolved in HNO3 or NH4 OH, were heated in H2 -N2 atmosphere. The pH value of solutions for CdSeO4 and NH4 SCN primarily determined the fraction of anions in CdSx Se1-x crystals. The anion content in crystals was dependent on the pH value of the solvent and/or heat-treatment temperature, and the sulfur fraction changed from 0.1 to 0.6. The optical absorption spectra were red-shifted as the selenium content and the crystal size increased, and the emission spectra showed a sharp band near the absorption edge position and a broad tail extending into the long wavelength. The optical band gap energies increased reciprocally proportional to the square of the crystal size. 相似文献
9.
Rats were fed a diet supplemented with corn oil (n-3 deficient), soy oil, or a mixture containing 8% 22∶6n-3 ethyl ester for
6 wk. The hepatic capacities for the β-oxidation and synthesis of 22∶6n-3, in addition to the acylation of lysophosphatidate,
were tested in vitro. In rats that were fed a 22∶6n-3-enriched diet, both the β-oxidation of 22∶6n-3 and elongation of 20∶5n-3 were enhanced compared
to those in rats fed the other diets. Acylation of lysophosphatidate was also enhanced in rats fed a 22∶6n-3-enriched diet,
while the rate of dephosphorylation of phosphatidate was not changed. The amount of 22∶6n-3 in the liver was much less than
that consumed in a docosahexaenoic acid-enriched diet. These results suggest that a significant amount of dietary 22∶6n-3
was degraded via β-oxidation, and that a portion of the retroconverted 20∶5n-3 was recycled for the synthesis of 22∶6n-3. The recycling of
20∶5n-3 might contribute to the low level of 22∶6n-3 in rats fed an n-3-deficient diet. 相似文献
10.
Makoto Kanazawa Gregory M. Kobele Jens Michaelis Sylvain Salvati Ryo Yoshinaka 《Theory of Computing Systems》2014,55(1):250-278
Seki et al. (Theor. Comput. Sci. 88(2):191–229, 1991) showed that every m-multiple context-free language L is weakly 2m-iterative in the sense that either L is finite or L contains a subset of the form \(\{ u_{0} w_{1}^{i} u_{1} \cdots w_{2m}^{i} u_{2m} \mid i \in \mathbb {N}\}\) , where w 1?w 2n ≠ε. Whether every m-multiple context-free language L is 2m-iterative, that is to say, whether all but finitely many elements z of L can be written as z=u 0 w 1 u 1?w 2m u 2m with w 1?w 2m ≠ε and \(\{ u_{0} w_{1}^{i} u_{1} \cdots w_{2m}^{i} u_{2m} \mid i \in \mathbb {N}\} \subseteq L\) , has been open. We show that there is a 3-multiple context-free language that is not k-iterative for any k. 相似文献