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排序方式: 共有162条查询结果,搜索用时 46 毫秒
1.
K Jin-no M Tanimizu I Hyodo Y Nishikawa Y Hosokawa H Endo T Doi K Mandai H Ishitsuka 《Canadian Metallurgical Quarterly》1998,82(7):1260-1267
BACKGROUND: Platelet-derived endothelial cell growth factor (PD-ECGF) is an angiogenic factor that is expressed in various cancer tissues. Little is known regarding plasma PD-ECGF levels in patients with chronic liver disease such as chronic hepatitis (CH), cirrhosis, and hepatocellular carcinoma (HCC) with cirrhosis. The expression of PD-ECGF in HCC tissues also remains to be clarified. METHODS: Plasma PD-ECGF levels in patients with chronic liver disease were determined with an enzyme-linked immunoadsorbent assay system using the mouse monoclonal antibodies specific to PD-ECGF. These were cross-sectionally compared among groups of normal persons, CH, cirrhosis, and HCC patients. The HCC patients were classified into two groups based on TNM stage: early and advanced stage disease groups. PD-ECGF expressions in HCC tissues were immunohistologically examined. RESULTS: The plasma PD-ECGF levels from the normal individuals and those with CH, cirrhosis, and HCC specimens were 4.2+/-0.5, 4.3+/-0.6, 4.6+/-1.1, and 6.0 +/-2.5 U/mL, respectively. The plasma PD-ECGF concentration was highest in HCC (P < 0.05). No significant difference was found among the normal subjects, CH, and cirrhosis specimens. Plasma PD-ECGF concentrations were significantly higher in the advanced stage disease HCC group compared with the early stage disease group (6.75+/-2.62 U/mL vs. 4.19+/-0.34 U/mL) (P < 0.05). Immunohistochemical expression of PD-ECGF in HCC cells increased significantly compared with normal liver cells (P < 0.05). CONCLUSIONS: Circulating PD-ECGF plasma level might be a new tumor marker for progression in patients with HCC. Immunohistological findings correspond to elevation of the plasma PD-ECGF in HCC patients. It is possible that increased production of PD-ECGF in HCC cells causes abundant neovascularization. 相似文献
2.
A compact Ku -band phase-locked oscillator module has been developed in a full MMIC (monolithic microwave integrated circuit) configuration. The module includes an MMIC voltage-controlled oscillator, an analog frequency divider, and interstage amplifiers. The constituent monolithic chips are integrated in a very small single-package module and operate at the target frequencies without any external trimming or matching network. The oscillator is tuned more than 1 GHz with a constant output amplitude. The frequency-divided output is also obtained over the whole tuning range. Spurious output is not found at any frequency up to 22 GHz. In spite of the very low-Q factor of GaAs monolithic circuitry, the oscillator phase noise exhibited is less than -80 dBc/Hz, due to the high-gain, high-speed phase lock 相似文献
3.
Etsuo Yamamura 《Papers in Regional Science》1985,56(1):201-213
This paper reports on studies into the controllability of the regional income disparities arising from multi-regional economic growth. The necessary condition is that no significant band of regional income disparities should result at the end of the planning period. The regional disparities among nine regions in Japan are explored using the interregional input-output technique and regional production functions. Furthermore, some potentially interesting research probes into the controllability of regional income disparities using the reference adaptive control technique are discussed. 相似文献
4.
The complexation between poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) was made by using double the molar quantity of either polymer component at pH 2 where the resulting complex completely precipitates. After the removal of the precipitate, PEO or PAA remaining in the supernatant was subjected to gel permeation chromatography to investigate the change in the molecular weight distribution (MWD) caused by the complexation. No remarkable difference is observed in the MWD curves for PEO[1] (Mw=1.37 × 104) before and after the complexation with PAA[1] (Mw=1.10 × 103) and PAA[2] (Mw=4.16 × 105). However, the MWD curves of PEO[2] (Mw=1.26 × 105) and PAA[2] become shortened and shift to the low molecular weight side after the complexation with PAA[1] or [2] and PEO[2], respectively. This tendency is enhanced by increasing the complexation temperature. From these results, it is indicated that the complexation between PEO and PAA deals with an equilibrium reaction, and the equilibrium constant is dependent on the chain length of both polymer components and also on the complexation temperature. 相似文献
5.
H. Furuta Y. FukudaT. Hara T. Haruna N. IshiharaM. Ishitsuka C. ItoM. Katsumata T. KawasakiT. Konno M. KuzeJ. Maeda T. MatsubaraH. Miyata Y. NagasakaK. Nitta Y. SakamotoF. Suekane T. SumiyoshiH. Tabata M. TakamatsuN. Tamura 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2012,662(1):90-100
We carried out a study of neutrino detection at the experimental fast reactor JOYO using a 0.76 tons gadolinium loaded liquid scintillator detector. The detector was set up on the ground level at 24.3 m from the JOYO reactor core of 140 MW thermal power. The measured neutrino event rate from reactor on-off comparison was 1.11±1.24(stat.)±0.46(syst.) events/day. Although the statistical significance of the measurement was not enough, backgrounds in such a compact detector at the ground level were studied in detail and MC simulations were found to describe the data well. A study for improvement of the detector for future such experiments is also shown. 相似文献
6.
7.
Stephen Matthew Lyth Huaiyu Shao Jianfeng Liu Kazunari Sasaki Etsuo Akiba 《International Journal of Hydrogen Energy》2014
Hydrogen storage is a crucial technology for the realization of a carbon-neutral society. However, few materials have been able to approach useful hydrogen storage capacity at reasonable temperatures and pressures. Graphene has an extremely high surface-area-to-weight ratio, is strong, cheap, chemically inert, and environmentally benign. As such it may be an ideal substrate for hydrogen storage. Here we present synthesis of graphene foam by combustion of sodium ethoxide. This technique is low-cost, scalable, and results in a three-dimensional graphene network with a surface area of more than 1200 m2/g. It is applied as a hydrogen storage material at liquid nitrogen temperature, with a capacity of 2.1 wt%. 相似文献
8.
Nitroxyl radicals are known to act as radical scavenging antioxidants. In the present study, a lipophilic nitroxyl radical,
cyclohexane-1-spiro-2′-(4′-oxyimidazolidine-1′-oxyl)-5′-spiro-1″-cyclohexane (nitroxyl radical I) was synthesized and its
antioxidant capacity was assessed in comparison with a hydrophilic nitroxyl radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (Tempol). Both nitroxyl radical I and Tempol inhibited methyl linoleate oxidation induced by free radicals, and the
efficacy increased with decreasing partial pressure of oxygen, the effect being more pronounced for nitroxyl radical I than
Tempol. Their hydroxylamines inhibited lipid peroxidation more effectively than their corresponding parent nitroxyl radicals.
In liposomal membranes, a synergistic effect was observed in the combination of nitroxyl radical I with ascorbic acid, whereas
only an additive effect was observed between Tempol and ascorbic acid. The present study suggests that nitroxyl radical I
and its hydroxylamine may act as potent antioxidants, especially in combination with ascorbic acid under hypoxic conditions. 相似文献
9.
Miyanishi N Iwamoto Y Watanabe E Odaz T 《Journal of Bioscience and Bioengineering》2003,95(2):192-195
We prepared a beta-1,3-glucan oligomer (DP> or = 4) from laminarin (DP: 25-30) derived from Laminaria digitata with beta-1,3-glucanase, and examined its effect on human peripheral blood monocytes. Conditioned medium prepared by incubating monocytes (MC-CM) with the beta-1,3-glucan oligomer showed strong inhibitory activity against the proliferation of human leukemic U937 cells. Since the beta-1,3-glucan oligomer had no direct cytotoxic effect on U937 cells up to 1000 microg/ml, the cytotoxicity of the MC-CM may be due to cytotoxic cytokines produced from monocytes stimulated by the beta-1,3-glucan oligomer. On the other hand, the MC-CM prepared with original laminarin had little effect on the growth of U937 cells. The cytotoxicity of the MC-CM prepared with the beta-1,3-glucan oligomer was significantly reduced by an anti-TNF-alpha antibody, but the anti-TNF-beta antibody had no effect. Our results suggest that the enzymatically depolymerized beta-1,3-glucan oligomer induces TNF-alpha production from human monocytes. 相似文献
10.
T. Murakami S. Ogawa N. Ishitsuka K. Kumagai G. Saito 《International journal of remote sensing》2013,34(7):1335-1348
Nine scenes of SPOT/HRV data obtained in eight different months in 1997 were evaluated for crop discrimination in the Saga Plains, Japan. All images were atmospherically corrected with the 6S code. Annual Normalized Difference Vegetation Index (NDVI) profiles were generated to characterize seasonal trends in six cropping systems (rice, rice-winter cereal, soybean, soybean-winter cereal, lotus, and rush). The dataset of this study showed the unique temporal change patterns of NDVI for each cropping system. Separability analyses determined optimal scene combinations for the highest accuracy in classifying the cropping systems. The scene combinations for the accurate classification of cropping systems were obtained from three separability measurements (Euclidean spectral distance, divergence, and Jeffries-Matsushita distance). Kappa statistics were applied to evaluate the classification accuracies. The four-scene combination that was derived from April, June, July and September classified the cropping systems almost as well as those combinations including more scenes. A colour composition technique applied to the three-scene combination that showed the highest separability also discriminated each cropping system. Based on these results, we can request observations during specific time intervals considering local crop calendars and environmental conditions. 相似文献