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991.
Previous studies have revealed that protein kinase C (PKC) is responsible for malignant progression. In the present study, we investigated the potent inhibitory effects of an antiestrogen, toremifene, on PKC-mediated cellular adhesion. A phorbol ester, phorbol 12-myristate 13-acetate (PMA), significantly enhanced alpha2beta1 integrin-dependent adhesion of MCF-7 breast carcinoma cells. This PMA-induced adhesion was partially inhibited by incubating cells with toremifene prior to PMA exposure in a time- and dose-dependent manner. FACS analysis demonstrated that the PMA-induced alpha2beta1-dependent cellular adhesion was accompanied with elevated expression of alpha2beta1+integrin subunit on the cell surface. However, toremifene did not affect the elevated expression levels of these integrins but rather the avidity of alpha2beta1 integrin. We concluded that toremifene inhibited cellular adhesion activated by PMA, probably through mechanism which inhibits PKC.  相似文献   
992.
Abstract— A 3.1‐in.‐diagonal 2‐D/3‐D LCD with a novel pixel arrangement, called horizontally double‐density pixels (HDDP), for high‐quality 3‐D images has been developed. 3‐D visibility has been improved by broadening the qualified stereoscopic viewing space (QSVS) where high‐quality 3‐D images can be seen. In order to evaluate the QSVS, optical characterization methods, based on the ergonomics for stereoscopy, such as 3‐D crosstalk, interocular luminance difference and 3‐D moiré have been proposed. The implementation results show that these methods can correctly evaluate high‐visibility autostereoscopic displays.  相似文献   
993.
This paper proposes a portable compact suction pad unit for the parallel grippers of a mobile manipulation robot to place items for product display. In addition, this paper includes verification of the unit’s mechanism. Given that robots have to hold various items, we propose an operation method by which the parallel gripper holding the compact suction pad unit switches between a pinching mode and a vacuum suction mode depending on the item being placed. The compact suction pad unit is self-contained, with all the devices necessary for the suction operation inside the unit. The suction operation is switched on and off wirelessly by an external host system controller. The compact suction pad unit produced a suction force of about 5.6?N at an allowable inclination angle of 15°. We demonstrated in a competition that our proposed operation method of the compact suction pad unit is useful by having it place a beverage in a cup with lid and a boxed lunch.  相似文献   
994.
Controlling chaos in a switched arrival system   总被引:2,自引:0,他引:2  
We consider a switched arrival system with three buffers. We assume that the input rate of work and the processing time per unit are constant. Chase et al. show that the system is chaotic. In this article, we propose a method for stabilization of an unstable periodic orbit embedded in a chaotic attractor by changing the limited continuous processing time.  相似文献   
995.
Research and development on nuclear waste transmutation are being carried out with a special emphasis placed on dedicated accelerator-driven systems at the Japan Atomic Energy Research Institute under the Japanese OMEGA Program. The reference accelerator-driven system design employs eutectic lead-bismuth as spallation target material and coolant. The fuel for the subcritical core is minor-actinide mononitride. The system consists of a 1.5GeV, 14mA proton accelerator and an 800MWt subcritical core with an effective neutron multiplication factor of 0.95. The transmutation rate of minor actinides is approximately 250 kg/y at 80% load factor. The design has salient features that the coolant inventory is large due to the tank-type configuration, the temperature rise through the core is relatively low, and the power conversion is operated on a saturated steam turbine cycle. These features make the plant response to a beam trip slow and much less demanding.  相似文献   
996.
辐射诱导IEC-6细胞MAPK信号转导途径的激活   总被引:2,自引:0,他引:2  
研究检测了γ辐射对IEC-6肠上皮细胞丝裂原激活的蛋白激酶(MAPKs)的激活效应。6Gyγ辐射未引起ERK蛋白磷酸化的显著改变,而辐照射后30minJNK与p38MAPK蛋白磷酸化显著增强,ERK、JNK与p38MAPK的总蛋白表达水平未见明显的变化。受照后12h细胞存活率显著降低。整. 螯合细胞内Ca^2 可几乎完全抑制γ辐照引起的JNK与p38MAPK的蛋白磷酸化,而清除细胞外Ca^2 却无此作用。p38MAPK的激活与γ辐射诱导的细胞凋亡显著相关,而ERK则无明显的关联。实验结果表明,γ辐射是一种强的JNK与p38MAPK激活因素,并且细胞内储存Ca^2 的释放在γ辐射诱导的IEC-6细胞MAPKs激活与细胞凋亡过程中起重要作用。  相似文献   
997.
Temperature fluctuation in fluid causes high cycle thermal fatigue in structure materials according to temperature distributions and time variations. A mixing tee is one of typical geometries where temperature fluctuation occurs. In the nuclear reactors and general plants, an elbow is often used near the mixing tee and it brings biased velocity distribution and also the secondary flow. In this study, influences of upstream elbow in the main pipe were studied in a water experiment of mixing tee with the elbow. Temperature distribution in the mixing tee was measured by a movable thermocouple tree and velocity field was measured by a high speed PIV. The temperature fluctuation at the mixing tee with the upstream elbow had the large component at low frequency in comparison with the straight case. The effect of the upstream elbow is significant to evaluate the high cycle thermal fatigue in the mixing tee because of larger importance of low frequency fluctuation on the point of fluid temperature-stress conversion.  相似文献   
998.
SUMMARY: Mice lacking p27(Kip1) have been created by gene targeting in embryonic stem cells. These mice are larger than the control animals, with thymus, pituitary, and adrenal glands and gonadal organs exhibiting striking enlargement. CDK2 activity is elevated about 10-fold in p27(-/-) thymocytes. Development of ovarian follicles seems to be impaired, resulting in female sterility. Similar to mice with the Rb mutation, the p27(-/-) mice often develop pituitary tumors spontaneously. The retinas of the mutant mice show a disturbed organization of the normal cellular layer pattern. These findings indicate that p27(Kip1) acts to regulate the growth of a variety of cells. Unexpectedly, the cell cycle arrest mediated by TGFbeta, rapamycin, or contact inhibition remained intact in p27(-/-) cells, suggesting that p27(Kip1) is not required in these pathways.  相似文献   
999.
Streptococcus bovis 148 was found to produce L-(+)-lactic acid directly from soluble and raw starch substrates at pH 6.0. Productivity was highest at 37 degrees C, with 14.7 g/l lactic acid produced from 20 g/l raw starch. The yield and optical purity of L-lactic acid were 0.88 and 95.6%, respectively.  相似文献   
1000.
Orthogonal frequency-division multiplexing (OFDM) can achieve remarkable performance in terms of spectral efficiency, but its power amplifier efficiency becomes poor because of its high peak-to-average power ratio (PAPR) nature of transmitted signals. Trellis shaping is an effective method to reduce peak and average power without signal distortion at the cost of transmitter complexity and its performance depends on the metric used for the trellis decoder. Several metrics, defined in either time or frequency domain, have been proposed in the literature. In many practical OFDM systems, however, slight nonlinearity is tolerable as long as the resulting distortion meets the system requirements such as bit error rate (BER) and spurious level of transmitted signals. In this paper, we make a thorough performance comparison of trellis-shaped uncoded OFDM systems with different metrics in terms of complexity, achievable PAPR, and resulting BER as well as power spectrum in a practical channel where the signal envelope is distorted by a power amplifier (PA). Our study shows that the metric designed in frequency domain is mostly favorable in such a scenario.  相似文献   
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