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排序方式: 共有809条查询结果,搜索用时 62 毫秒
101.
102.
103.
Phase I and pharmacologic study of irinotecan in combination with cisplatin for advanced lung cancer
N Masuda M Fukuoka S Kudoh Y Kusunoki K Matsui N Takifuji K Nakagawa M Tamanoi T Nitta T Hirashima 《Canadian Metallurgical Quarterly》1993,68(4):777-782
Macroscopic T-type Ca2+ currents, which are often observed in fetal and neonatal cardiac muscle cells, were not found in normal (0 of 17) adult feline ventricular myocytes. However, they were present in most (15 of 21) myocytes isolated from adult feline left ventricles with long-standing pressure-overload-induced hypertrophy. This is the first study to provide evidence in a large mammal, such as the cat, that T-type Ca2+ channels may be reexpressed in adults in association with hypertrophy resulting from slow progressive pressure overload. Importantly, this expression was stable for the duration of the hypertrophy process and was not associated with abrupt pressure overload. T-type Ca2+ currents were separated from L-type Ca2+ currents by exploiting the differences in their voltage dependence of steady-state inactivation. Depolarizations from -80 mV revealed a rapidly activating inward current that peaked in magnitude at -30 mV (-1.8 +/- 0.9 [mean +/- SD] pA/pF) and fully inactivated within 100 milliseconds in 15 of 21 hypertrophied myocytes studied. Further depolarizations activated progressively less T-type Ca2+ current, so that at +10 mV the L-type Ca2+ current predominated. In the hypertrophied myocytes that demonstrated both T-type and L-type Ca2+ currents, two distinct peaks occurred in their current-voltage relations. T-type Ca2+ currents were not evident in any of the 17 normal adult feline left ventricular myocytes studied. The purpose of T-type Ca2+ currents in hypertrophy is unclear. However, their presence may make hypertrophied myocardium more prone to spontaneous action potentials and increase the likelihood for arrhythmias in partially depolarized hypertrophied myocardium. 相似文献
104.
This paper presents a two-degree-of-freedom (two-DOF) linear encoder which can measure the position along the moving axis (X-axis) and the straightness along the axis vertical to the moving axis (Z-axis) of a precision linear stage simultaneously. The two-DOF linear encoder is composed of a reflective-type scale grating and an optical sensor head. A reference grating, which is identical to the scale grating except the scale length, is employed in the optical sensor head. Positive and negative first-order diffracted beams from the two gratings are superposed with each other in the optical sensor head to generate interference signals. The optical configuration is arranged in such a way that the direction of displacement in each axis can also be detected. A prototype two-DOF linear encoder is designed and constructed. The size of the optical sensor head is about 50 mm (X) × 50 mm (Y) × 30 mm (Z) and the pitch of the grating is 1.6 μm. It has been confirmed that the prototype two-DOF linear encoder has sub-nanometer resolutions in both the X- and Z-axes. 相似文献
105.
Go Kagiya Ryohei Ogawa John A. Cook Rajani Choudhuri Masanori Hatashita Yoshikazu Tanaka Bill G. DeGraff James B. Mitchell 《Journal of Bioscience and Bioengineering》2010,110(1):118-123
A promoter that augments gene expression in response to stimulation of ionizing radiation would be a desired tool for radiogenetic therapy, a combination of radiotherapy and gene therapy. Although various promoters occurring naturally or artificially have been used for researches, one showing higher reactivity to ionizing radiation is desirable. In the present study, we attempted to improve a radiation-responsive promoter of the p21 through a technique called DNA shuffling. A library of DNA fragments was constructed by re-ligation of randomly digested promoter fragments and improved promoters were chosen out of the library. We repeated this process twice to obtain a promoter showing 2.6-fold better reactivity to ionizing radiation compared with its parent, p21 promoter after 10 Gy γ-ray irradiation. Nucleotide sequence analyses revealed that the obtained promoter was densely packed with some of the cis-acting elements including binding sites for p53, NF-κB, NRF-2, AP-1 and NF-Y more than p21 promoter. In addition, it was shown that its induction by ionizing radiation was dependent upon p53 status of a cell line, suggesting that the promoter retained properties of the p21 promoter. This technique is simple and efficient to improve a promoter responsive to other stimulus of interest besides IR. 相似文献
106.
Sayaka Yanagida Akira Nakajima Takayoshi Sasaki Toshihiro Isobe Yoshikazu Kameshima Kiyoshi Okada 《Applied Catalysis A: General》2009,366(1):130
Keggin ions (PW12O403− (PW12), SiW12O404− (SiW12), H2W12O406− (H2W12)) and TiO2 hybrid thin films were prepared using the layer-by-layer method. Their photocatalytic activities were investigated using gaseous 2-propanol decomposition. All films were transparent in the visible wavelength range. For 2-propanol decomposition, H2W12 was the most effective for the combination with TiO2 despite having the smallest TiO2 deposition amount. The photocatalytic activity of the PW12–TiO2 hybrid film was increased 2.3 times by visible light with UV illumination. This increase was less remarkable for hybrid films of other Keggin ions, suggesting that the visible light excitation of reduced PW12 plays an important role in the enhancement of 2-propanol decomposition. 相似文献
107.
Yoshikazu Takaku Lazuardi Felicia Ikuo Ohnuma Ryosuke Kainuma Kiyohito Ishida 《Journal of Electronic Materials》2008,37(3):314-323
Chemical reactions between Cu substrates and Zn-Al high-temperature solder alloys, Zn-4Al and Zn-4Al-1Cu (mass%), at temperatures
ranging from 420°C to 530°C were experimentally investigated by a scanning electron microscope using backscattered electrons
(SEM-BSE) and an electron probe microanalyzer (EPMA). Intermediate phases (IMPs), β(A2) or β′(B2), γ(D82), and ε(A3) phases formed and grew during the soldering and aging treatments. The consumption rate of the IMP for Cu substrates
is described by the square root of t in both the alloys, while the additional Cu in the molten Zn-Al alloy slightly suppresses the consumption of Cu substrates.
The growth of IMPs during soldering treatment is controlled by the volume diffusion of constituent elements, and its activation
energy increases in the order of Q
ε < Q
γ < Q
β. In view of the aging process, the growth of IMPs is considered to be controlled by the volume diffusion. In particular,
the layer thickness of γ rapidly grows over 200°C, although the thickness of the β layer grows very slowly. 相似文献
108.
Saito W. Nitta T. Kakiuchi Y. Saito Y. Tsuda K. Omura I. Yamaguchi M. 《Electron Device Letters, IEEE》2008,29(1):8-10
A boost converter with a 940-V/4.4 A GaN-HEMT as the main switching device was demonstrated to show the possibility of using high-voltage GaN-HEMTs in power electronic applications. The demonstrated circuit achieved an output power of 122 W and a power efficiency of 94.2% under a drain peak voltage as high as 350 V and a switching frequency of 1 MHz. The dual field-plate structure realized high-voltage switching operation with high power efficiency as dynamic on-resistance was suppressed by an increase of the current collapse phenomena. 相似文献
109.
Yoshikazu Kobayashi Hikari Hamada Yasuhiro Yamaguchi Hidekazu Ikezaki Kiyoshi Toko 《IEEJ Transactions on Electrical and Electronic Engineering》2009,4(6):710-719
This paper reports the development of membrane sensors based on an artificial lipid and plasticizers with high selectivity and sensitivity to drug bitterness by using bis(1-butylpentyl) adipate (BBPA), bis(2-ethylhexyl) sebacate (BEHS), phosphoric acid tris(2-ethylhexyl) ester (PTEH), and tributyl o-acetylcitrate (TBAC) as a plasticizer and phosphoric acid di-n-decyl ester (PADE) as an artificial lipid to optimize surface hydrophobicity of the sensors. In addition, a sensor with highly correlated bitterness sensory score was developed by blending BBPA and TBAC to detect the bitterness suppression effect of sucrose, and other bitter-masking materials. Therefore, this sensor can be used to evaluate the bitterness of various drug formulations with high accuracy. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
110.
Satoshi Wada Hiroaki Yasuno Takuya Hoshina Hirofumi Kakemoto Yoshikazu Kameshima Takaaki Tsurumi 《Journal of Electroceramics》2008,21(1-4):198-201
Barium titanate (BaTiO3) crystallites with various particle sizes from 22 to 500 nm were prepared by the two-step thermal decomposition method of barium titanyl oxalate. Various characterizations revealed that these particles were impurity-free, defect-free, dense BaTiO3 particles. The powder dielectric measurement clarified that the dielectric constant of BaTiO3 particles with a size of around 58 nm exhibited a maximum of over 15,000. To explain this size dependence, the THz region dielectric properties of BaTiO3 fine particles, especially Slater mode frequency, were measured using the far infrared (FIR) reflection method. As the result, the lowest Slater mode frequency was obtained at 58 nm. This tendency was completely consistent with particle size dependence of the dielectric constant. 相似文献