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61.
Cell transformation in vitro is a model of carcinogenesis in vivo. Two-stage transformation assay increases the sensitivity of cells to chemicals and permits detection of carcinogens acting as initiating agents. [60]Fullerene (C60) was cytotoxic in BALB/3T3 cells when it was irradiated by visible light, but not without light irradiation. Under conditions when C60 was cytotoxic, it acted as an initiating agent for cell transformation, but it did not act as a complete transforming agent. the initiating activity of visible-light-irradiated C60 was statistically significant in a modified two-stage transformation assay including a procedure for replating cells treated by C60 and light, but it was equivocal in the standard two-stage transformation assay.  相似文献   
62.
We developed the world's smallest‐profile 32‐in. HDTV PDP. By improving the luminous efficiency, a luminance of 650 cd/m2 and power consumption (discharge and driving circuit) of 200 W or less was achieved. Moreover, incorporating an advanced color compensating (ACC) filter improved the PDP's color‐reproduction capability, better than that of CRTs.  相似文献   
63.
The effect of aluminium on the polymerization of silicic acid was studied at pH 7, 8 and 9 in the aluminium concentration range of 0–26 ppm (Al) by spectrophotometry, gel chromatography and 27Al NMR. Retarding and accelerating effects of aluminium on the growth of polysilicic acid particles and on the reaction between monosilicic acid and polysilicic acid were observed by changing the pH. It is suggested that the accelerating effect on the reaction between polysilicic acid particles is due to the formation of aluminium hydroxide on the surface of polysilicic acid. The rate of decrease in the monosilicic acid concentration in the presence of aluminium was faster than that in the absence of aluminium at pH 9, because monosilicic acid could be adsorbed rapidly on the aluminium hydroxide. From the results it was presumed that the formation of aluminium hydroxide on the solid surface may accelerate the deposition of silicic acid from geothermal water.  相似文献   
64.
We report herein the unusual case of a 59-year-old woman with Plummer-Vinson syndrome who developed gastric cancer. The patient had a longstanding history of dysphagia and iron deficiency anemia, for which she had sporadically taken iron supplements that improved the dysphagia to some extent, but not completely. Owing to her tolerance of the dysphagia, she had not been taking iron supplements for the past 17 years. On admission, she was in fair nutritional condition and not anemic. Blood chemistry results were all normal, including the serum iron level. Gastrointestinal radiographic series demonstrated cervical esophageal webs and advanced gastric cancer. Her dysphagia was successfully treated by endoscopic bougienage through the webs, and a distal partial gastrectomy with nodal dissection was performed. Histology of the resected stomach revealed atrophic mucosal change and, by chance, an adenomatous lesion in addition to adenocarcinoma. Her postoperative course was uneventful and she is now well, without any signs of recurrence. Although Plummer-Vinson syndrome is known to be associated with upper alimentary tract cancers, gastric cancer is extremely rare. A discussion on the etiology of Plummer-Vinson syndrome and its link with potential carcinogenesis follows this case report.  相似文献   
65.
66.
The diffusion in iridium-rich Ir-Nb alloys has been studied by single-phase interdiffusion experiments. The chemical diffusion coefficient has been measured for the primary fcc solid-solution and theL12 ordered compound Ir3Nb in the temperature range between 1650 and 1950 °C, using Ir/Ir-8Nb and Ir-26Nb/Ir-28Nb diffusion couples, respectively (numbers indicate mol%). While the chemical diffusion coefficient in the solid-solution phase is close to the tracer self-diffusion coefficient of pure iridium, the diffusion in the compound phase is extremely slow: the chemical diffusion coefficient is 1/40 to 1/50 of that in the solid solution. The low diffusion rate in the compound must be beneficial for high-temperature performance of refractory superalloys based on the Ir-Nb system. This article was presented at the Multicomponent-Multiphase Diffusion Symposium in Honor of Mysore A. Dayananda, which was held during TMS 2006, 135th Annual Meeting and Exhibition, March 12–16, 2006, in San Antonio, TX. The symposium was organized by Yongho Sohn of University of Central Florida, Carelyn E. Campbell of National Institute of Standards and Technology, Richard D. Sisson, Jr., of Worcester Polytechnic Institute, and John E. Morral of Ohio State University.  相似文献   
67.
Terpendole E is first natural product found to inhibit mitotic kinesin Eg5, but its inhibitory mechanism remains to be revealed. Here, we report the effects of terpendole E and 11ketopaspaline (a new natural terpendole E analogue) on the Eg5–microtubule interaction and in several Eg5 mutants. 11‐Ketopaspaline is a shunt product from terpendole E, and it shows potent inhibitory activity against the microtubule‐stimulated ATPase activity of Eg5. Unlike other Eg5 inhibitors, such as S‐trityl‐L ‐cysteine (STLC) and GSK‐1, both terpendole E and 11‐ketopaspaline only partially inhibited Eg5–microtubule interaction. Furthermore, terpendole E and 11‐ketopaspaline inhibited several Eg5 mutants that are resistant to STLC (Eg5D130A, Eg5L214A) or GSK‐1 (Eg5I299F, Eg5A356T), but with the same extent of inhibition against wild‐type Eg5. Because Eg5D130A and Eg5L214A show cross‐resistance to most known Eg5 inhibitors, which bind the L5 loop, these results suggest that terpendole E and its analogues have a different binding site and/or inhibitory mechanism to those for L5 loop‐binding type Eg5 inhibitors.  相似文献   
68.
The effects of impurity Zr on dissolution behavior into nitric acid of sintered Mo pellets were investigated using simulated fuels to accumulate basic data and knowledge concerning the matrix of Mo-cermet fuels. Mo pellets containing 1– 10 mol% Zr were prepared by conventional powder metallurgical route. After characterization tests using optical microscopy (OM), X-ray diffraction and secondary electron microscopy-energy dispersive X-ray spectrometry (EDX), the sintered pellets were subjected to dissolution tests by nitric acid. The apparent dissolution rate of Mo pellets containing impurity Zr was found to be followed by the first-order chemical reaction form, which is generally known as a simple chemical reaction. The rate of dissolution of sintered Mo-cermet fuels by nitric acid was found to decrease with the increase of the amount of impurity Zr.  相似文献   
69.
The flow of a high‐speed unsteady jet is analyzed using computational fluid dynamics for an incompressible flow with the k–ε turbulence model. The pseudo‐nozzle concept is applied to the inlet condition with a large pressure gradient. The results show that the time history of the jet development agrees with the experimental data for methane and hydrogen fuels. In addition, the effect of the injection condition on the development of the jet tip is well described with this model. Furthermore, the effects of inlet conditions of the turbulence intensity and scale on the flow are investigated. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(1): 1– 12, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20141  相似文献   
70.
Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zerovalent, which shows the difficulty with in-situ synthesis of a significant fraction of zerovalent iron in the microporous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogeneous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI.  相似文献   
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