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61.
Previous somatic cell hybridization studies have assigned many human cell lines to one of four complementation groups (A-D) for immortalization. We report here that the A1698DM cell line, which contains selectable markers and has previously been defined as the immortalization group D representative, was derived from T24 cells rather than A1698. A1698DM did not undergo senescence when fused with cell lines assigned to groups A, B, or C. This raises the possibility that this cell line has undergone further evolution and lost multiple putative senescence genes so that it is now unable to complement any, or most, other cell lines for senescence. Cell lines previously assigned to group D may, therefore, be heterogeneous with respect to the genetic changes that resulted in their immortalization. This has important implications for strategies to clone senescence genes based on complementation groups. 相似文献
62.
S Kawakita 《Canadian Metallurgical Quarterly》1996,44(9):899-902
A 73-year-old male, who underwent resection of soft palate cancer and was under treatment for esophageal ulcer at our medical department, complained of palpitation. On the suspicion of hyperthyroidism, enzyme immunoassay (EIA) was performed. T3 and T4 were increased, and FT4 and TSH were normal. However, T3 and T4 measured again by radioimmunoassay (RIA) were normal. Therefore, the patient serum was examined for interfering substances such as antibody against bovine intestinal alkaline phosphatase (ALP) and heterophilic antibody. Substances interfering with ALP and anti-rabbit IgG human antibody were detected. It is necessary to consider the possible presence of these substances when results of EIA are evaluated. 相似文献
63.
K Hiramatsu M Sugimoto S Kamei M Hoshino K Kinoshita K Iwasaki M Kawakita 《Canadian Metallurgical Quarterly》1997,123(10):539-545
Recently, we found N1,N8-diacetylspermidine (Ac2Spd) and N1,N12-diacetylspermine (Ac2Spm) in human urine, and noted that their amount increased significantly in patients with urogenital malignancies. Previous findings that simultaneous reference to these diacetylpolyamines is useful in distinguishing cancer patients from healthy persons were confirmed by more recent analytical data on urine samples from several cancer patients. Further examination revealed that urinary Ac2Spm and Ac2Spd tended to decrease when cancer patients were treated and entered partial remission. In cases where the Ac2Spm and Ac2Spd levels were normal or near-normal after treatments, the prognosis of the patients was generally good. In contrast, when their level remained far above the normal limits after apparently effective treatment, the prognosis of the patients was poor. When a patient is in remission for more than 3 years, urinary levels of both Ac2Spm and Ac2Spd are stabilized and stay below the normal limits, with rare exceptions. The recurrence of a cancer as well as the complication of a second one during the period of follow-up examination was accompanied by elevation of urinary diacetylpolyamines. These observations indicate that urinary Ac2Spm and Ac2Spd are useful as prognostic indicators after treatment and during follow-up examination of cancer patients. 相似文献
64.
High temperature corrosion of nanoceria coated 9Cr-1Mo ferritic steel in air and steam 总被引:1,自引:0,他引:1
In this article, air and steam oxidation resistance of bare and nanoceria coated 9Cr-1Mo ferritic steel at 650 °C for 500 h is reported. The kinetics of the oxidation process and the changes in the morphology and the chemistry for both the specimens were analyzed by backscattered electron and EPMA mapping. The nanoceria coated 9Cr-1Mo ferritic steel showed better oxidation resistance than uncoated steel under similar conditions. The thickness of the oxide scales formed on the coated samples was significantly reduced as compared to the uncoated substrates. The effectiveness of such a thin and simple nanocoating to improve the oxidation resistance of 9Cr-1Mo ferritic steel compared to the pristine is attributed to the change in the migration of cations from outward to inward diffusion of oxygen as the major mechanism. 相似文献
65.
Yasunari Ishikawa Seiji Kuroda Jin Kawakita Matsufumi Takaya 《Surface & coatings technology》2007,201(8):4718-4727
WC-20 mass%Cr3C2-7 mass%Ni powder was sprayed onto low-carbon steel substrates by a commercial high velocity oxygen-fuel (HVOF) spray process as well as by an improved HVOF process equipped with a gas shroud attachment. The latter process utilizes a nitrogen gas flow to shield the region between the spray gun and the substrate in order to suppress the material's degradation caused by reaction with air such as oxidation and decarburization. Some coatings were further heat-treated in air at 773 K for 30 h to form a thin oxide film on the surface. The sliding wear properties of these coatings against an iron pin were evaluated by using a pin-on-disk wear tester. The specific wear rate of the as-sprayed cermet coatings prepared under the conventional spray condition was about three times higher than that of the chrome plating but by using the gas shroud, the wear rate was reduced to the same level with the chrome plating. The specific wear rate could be further decreased by the oxidation heat-treatment. It was found that a proper amount of oxides existing on the surface or within the coatings have a great beneficial effects on the wear properties such as to promote the transition from severe wear to mild wear and thus to reduce the wear rate remarkably. XPS analysis of the transfer particles collected from the wear track revealed a shift in the oxidation state of iron depending on the wear condition. 相似文献
66.
Takizawa K Fujii T Kawakita M Kikuchi H Fujikake H Yokozawa M Murata A Kishi K 《Applied optics》1997,36(23):5732-5747
Spatial light modulators (SLM's) consisting of a polymer-dispersed liquid crystal (PDLC) film and a Bi(12)SiO(20) photoconductor are discussed and demonstrated. This device, which uses light scattering in the PDLC film, has several advantages including no polarizer, a low optical loss, and video-rate operation. The device was designed by use of an electrical-image method. High-definition SLM's with a limiting resolution (36-50 line pairs/mm) were fabricated by stacking of an optimized mirror and the PDLC film. The device, which was incorporated into a Schlieren system with a 1-kW xenon lamp, provided high-contrast video images and a total luminous flux of 1000 lm. 相似文献
67.
Yoji Koike Shuichi Takeuchi Hidetaka Sato Yuichiro Hama Masatsune Kato Yasuhiro Ono Susumu Katano 《Journal of Low Temperature Physics》1996,105(3-4):317-322
The effects of substitution of Y or Bi on the low-temperature structural phase transition, electronic anomaly and superconductivity have been studied in La2-y-xYyBaxCuO La2-y-xBiyBaxCuO4 and La1.9-y-xTb0.1BiySrxCuO4 with x = 1/8. Moreover, an electronic anomaly, which is analogous to those observed in La2–xBaxCuO4 and La1.6-xNd0.4SrxCuO4 with x 1/8, has been found below about 60 K in the thermoelectric power measurements for the Zn-substituted La2–xSrxCu1–yZnyO4 with x 0.115 and y = 0.01 – 0.02. These experimental results support the conclusions by Tranquada et al. that static order of the stripe correlations of holes and spins, owing to pinning by the low-temperature structure or impurities (Zn in this case), is the origin of the electronic anomaly, leading to the suppression of superconductivity. 相似文献
68.
Tadayoshi Matsumori Atsushi Kawamoto Tsuguo Kondoh Tsuyoshi Nomura Hidetaka Saomoto 《Structural and Multidisciplinary Optimization》2017,56(3):619-629
This paper deals with a design method for boundary shapes using filtering techniques based on a partial differential equation (PDE). In shape optimization, it is known that oscillatory boundaries appear when design variables are directly assigned to the design boundaries. In addition, during the optimization process, discretized elements in a computational domain are distorted due to extremely large shape changes along the design boundaries. The distorted elements may cause accuracy deterioration or numerical instability in a forward problem. In this paper, we propose a shape optimization method by using the PDE as a low pass filter which prevents the oscillatory boundaries of the optimized design. For restricting the shape distortion of the discretized elements, the shear deformation of the elements is constrained in the optimization problem. Mathematical programming is used to find the boundary shapes under the KKT conditions. The effectiveness of the proposed method is demonstrated through numerical examples in solid and fluid mechanics. 相似文献
69.
Effect of the (Ba + Sr)/Ti ratio on the microwave‐tunable properties of Ba0.6Sr0.4TiO3 ceramics 下载免费PDF全文
Takashi Teranishi Riku Kanemoto Hidetaka Hayashi Akira Kishimoto 《Journal of the American Ceramic Society》2017,100(3):1037-1043
The impact of the (Ba + Sr)/Ti (A/B) ratio on the microwave‐tunable characteristics of diffuse phase transition (DPT) ferroelectric Ba0.6Sr0.4TiO3 (0.6‐BST) ceramics was investigated. The reduction in the lattice constant with increasing nonstoichiometry was attributed to introduced partial Schottky defects, i.e., and . The magnitude of the dielectric constant, ε′, at room temperature in the absence of an applied electric field was governed by the shift in the dielectric maximum temperature, Tm, because Tm was close to room temperature for the 0.6‐BST. The dielectric loss, tanδ, diminished as the ε′ decreased for 0.98≤A/B≤1.05, while the tanδ was much higher for A/B=0.95 having the greatest A‐site vacancy loading. The negatively charged and were mainly compensated by oxygen vacancies and likely partly compensated by holes, h?, which contributed to the electrical conduction. The tunability, T, at 100 MHz was almost constant at 20%–25% for A/B≥1.00 despite the reduction of the ε′, whereas T decreased for A/B<1.00 to ca. 10% for A/B=0.95 having the greatest A‐site vacancy loading. The results implied that the for larger A/B values was more efficient in generating nucleation sites in the polar nanoregions (PNRs) than the for smaller A/B values, thereby providing greater dipole polarization. Consequently, the figure of merit, FOM, reached its maximum of 250 at A/B=0.9875, which was ca. 155% higher than that of the stoichiometric BST. 相似文献
70.