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排序方式: 共有801条查询结果,搜索用时 15 毫秒
101.
E Ozawa S Noguchi Y Mizuno Y Hagiwara M Yoshida 《Canadian Metallurgical Quarterly》1998,21(4):421-438
Cutaneous sarcomas are uncommon tumors presenting many histological types. The diagnosis is based on pathological, immunohistochemical and sometimes ultrastructural studies. The development of cytogenetic and molecular analysis may constitute an additional aid to the diagnosis and classification. Prognosis and therapeutic strategies are established on the basis of various criteria using different types of staging and grading, but these classifications have not yet been standardized. The rarity of cutaneous sarcoma, and the diversity of clinical presentations account for the difficulties of management, which requires a multidisciplinary approach. 相似文献
102.
Isao Ikeda Yoshihide Ozawa Yohjl Nakatsuji Mitsuo Okahara 《Journal of the American Oil Chemists' Society》1987,64(7):1034-1037
A series of N-alkyl dihydroxy monoazacrown ethers (1) was synthesized, and their surface properties were investigated compared to those of N-alkyl monoazacrown ethers (2) and open chain oxyethylenated long chain alkylamines (3). The complexation ability of1 toward alkali metal cations, a distinguished characteristic of crown compounds, was deduced to work even in the aqeuous solution
from the values of
TCP, although it is weaker than typical monoazacrown ethers (2). The presence of two hydroxyl groups contributes to the large increase in hydrophilicity of monoazacrown ring and to the
large surface excess of the surfactant molecule (1). A small occupation area to the solution surface is noted as a characteristic feature of the title coumpound (1). 相似文献
103.
The main objective of the study was to develop systematic methods for improving CAL materials by comparing the five coursewares which were produced by independent authors and related to high school mathematics, science and engineering. Various kinds of evaluation were undertaken before, immediately before, during and immediately after CAL implementation; e.g. evaluators check on the drafts for courseware; evaluators check on the problems encountered in each frame while studying at the terminals; the readiness, pre- and post-tests; an anxiety scale; questionnaires for assessing any difficulties with learning in each chapter and each course; the course test; an image scale, an attitude scale and a line-connecting type of content analysis. Each courseware was evaluated and compared with others on the basis of the data analysis of tests and questionnaires as well as the learning history records, e.g., total learning duration, total number of passed frames, frequency of use of function keys, actual transitive path graph, actual average branch ratio, relative entropy in each frame and the index of educational effectiveness. A number of important evaluation items were selected by factor analysis. Finally an evaluation package instrument for improving CAL courseware were developed. 相似文献
104.
Taichi Sato Shuji Ikoma Fusaji Ozawa 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1983,33(8):415-420
The thermal transformation of anhydrous alumina obtained by the decomposition of the lactate, citrate and tartrate of aluminium has been examined by thermal analysis(TGA and DTA), infrared spectrophotometry and X-ray diffraction study. It is found that under an atmosphere of air the thermal decomposition of aluminium hydroxycarboxylates to anhydrous amorphous alumina, which transforms to α-alumina via γ-, δ- and θ-aluminas, proceeds as follows for Al[CH3CH(OH)COO]3, the decomposition of skeleton and the combustion of its decomposition products; for Al[CH2C(OH)CH2(COO)3] and Al2{[CH(OH)COO]2}3, dehydroxylation, decomposition of skeleton and the combustion of its decomposition products. 相似文献
105.
Sintering characteristics of three kinds of iron and FeCo alloy ultrafine powders (UFPs) in vacuum and a hydrogen atmosphere were examined by continuously measuring their dimensions, and observing their structural changes. The UFPs exposed to air contain mixtures of oxide and hydroxide phases. The oxide phase increased during heating in vacuum. The compacts of the UFPs shrunk slightly at temperatures between 450 and 700 K, where the surface oxides sintered, and then densified rapidly above 700 K. The shrinkage in a stream of hydrogen occurred at much lower temperatures than that in vacuum. The reduction reaction is ratecontrolled by an interface reaction and the reduction rate of the UFPs depends on the oxidation level, where the more highly oxidized UFPs tend to the lower reduction rate. Activation energies of the reduction rate constants of the iron UFPs and FeCo UFPs lie in the range 48–59 kJ mol–1. 相似文献
106.
K Ozawa H Miura T Tamagawa Y Hiyoshi K Nonogaki N Maeda G Watanabe N Sakamoto A Iguchi 《Canadian Metallurgical Quarterly》1993,53(25):1903-1909
We investigated the effects of intrahypothalamic or hippocampal injection of GABA receptor agonists on hyperglycemia induced by hippocampal neostigmine. Prior to the injection of neostigmine (50 nmol) into the hippocampus (HPC), muscimol (0.01-1 nmol) or baclofen (1 nmol) was injected into the bilateral ventromedial hypothalamus (VMH). Muscimol suppressed the hyperglycemia in a dose-dependent manner, but baclofen affected it only minimally. In contrast, neither hippocampal muscimol (1 or 2.5 nmol) nor baclofen (1 nmol) suppressed the hippocampal neostigmine-dependent hyperglycemia. Intrahypothalamic muscimol (1 nmol) also decreased the changes in hepatic venous plasma glucagon and epinephrine significantly. These results indicate that intrahypothalamic muscimol suppresses hyperglycemia caused by cholinergic neurons originating from the HPC, indicating existence of the location specificity. 相似文献
107.
n-alkylpolyoxyethylene surfactants (CnH2n+1O(CH2CH2O)mH; CnEm) showed a strong enhancing effect on the inactivation of lipopolysaccharide (LPS) by heat treatment over a wide range of temperatures. The effect of CnE8 (n = 10-16) was observed above the critical micelle concentration (CMC) and above the cloud point, and was influenced by the length of the alkyl chains. The efficacy of the surfactants was in the order C10E8 < C12E8, C16E8 < C14E8. However, the hydrophilic moiety seemed to have no influence. An 80-95% solution of n-butanol showed a similar effect, indicating that LPS was more effectively inactivated in the oily phase of the surfactants than in water. The effect of surfactant on the hydrodynamic diameter of LPS was the same before and after steam-heat treatment for 20 minutes at 121 degrees C. Each surfactant disaggregated LPS without alteration of the activity of LPS before the heat treatment. We consider that the surfactants interact with LPS in the region of lipid A in a manner that favors loss of the activities of LPS during heating. 相似文献
108.
Catalyst aging or formulation changes can cause a perturbation to the rate constant matrix of a monomolecular reaction system. The techniques of determining a perturbation matrix from a knowledge of the original rate constant matrix and the experimental reaction paths are discussed. Kubo's expansion form is shown to be useful for a short reaction time when the magnitude of a perturbation matrix is rather large. For small perturbations, the eigenvalues and eigenvectors of the perturbed system can be expanded into a Taylor series. 相似文献
109.
Methanol, ethanol, straight-chain propanol, isopropanol, straight-chain butanol, sec-butanol, tert-butanol, straight-chain pentanol, and iso-pentanol were used for the reaction of coal with NaOH-alcohol at 290 °C for 1 h. All the products dissolved in pyridine with an extraction yield > 80 wt%. Straight-chain alcohols are less reactive than the secondary alcohols owing to the differences in hydrogen donating ability. 相似文献
110.
T Shibahara H Noma M Yama Y Ozawa J Kaneko I Sawa L Sato 《Canadian Metallurgical Quarterly》1995,36(4):193-199
When we purify bone morphogenetic protein (BMP), its activity diminishes, and the quantity we are able to extract decreases. It is difficult to evaluate the effects of each of the processes involved in BMP purification because it is unstable. In order to resolve the problem, a modified bioassay method using only slight quantities of BMP which do not decrease its bone-forming activity, is needed. We transferred BMP separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) onto nitrocellulose membranes (NC) and cut out the bands. Then we used each band as implanted material. The NC membrane firmly bound the BMP activity fraction and held it in the implantation area of the mouse thigh. No formation of bone-like tissue was detected histologically at 14 days after the implantation, but, by 21 days after implantation, cartilage like tissue had clearly formed and newly formed bone was seen by 28 days. By implanting BMP transferred to individual NC membranes, we could perform a bioassay easily with small amounts of BMP without any reduction in activity. 相似文献