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91.
Capacitative calcium entry (CCE), the mechanism that replenishes intracellular calcium stores after depletion, is essential to intracellular calcium signaling. CCE is mediated by the channels in the plasma membrane generally referred to as "store operated channels (SOCs)". However, the molecular identity of the SOCs has never been determined, and the mechanism of the activation of SOCs remains to be elucidated. Recent studies have demonstrated that 2-aminoethoxydiphenyl borate (2-APB), which has been found to be an antagonist of inositol 1,4,5-trisphosphate receptors (IP3Rs), inhibits CCE, suggesting that IP3Rs channel activity is essential to the generation of CCE. However, CCE has also been reported to occur normally in IP3R-deficient cells. In order to resolve this discrepancy, we investigated the effect of 2-APB on CCE in IP3Rs-deficient cells. In response to store depletion with thapsigargin or N,N,N',N'-tetrakis (2-pyridylmethyl) ethylene diamine (TPEN), CCE was generated in IP3Rs-deficient cells the same as in wild-type cells, however, 2-APB abolished CCE in IP3Rs-deficient cells, despite the fact that this cell line does not possess functional IP3Rs. We also examined the effect of 2-APB on several types of TRP Ca2+ channels, which exhibit properties similar to those of SOCs. 2-APB had a different inhibitory effect on spontaneous and thapsigargin-induced Ba2+ influx in cells that transiently expressed individual TRP subtypes. These results suggest that the channel activity of IP3Rs is not essential to the generation of CCE in this cell line and that 2-APB inhibits CCE independently of the function of IP3Rs. 相似文献
92.
Motion Control of Passive Intelligent Walker Using Servo Brakes 总被引:1,自引:0,他引:1
We propose a new intelligent walker based on passive robotics that assists the elderly, handicapped people, and the blind who have difficulty in walking. We developed a prototype of the robot technology walker (RT walker), a passive intelligent walker that uses servo brakes. The RT walker consists of a support frame, two casters, two wheels equipped with servo brakes, and it has passive dynamics that change with respect to applied force/moment. This system is intrinsically safe for humans, as it cannot move unintentionally, i.e., it has no driving actuators. In addition, the RT walker provides a number of navigational features, including good maneuverability, by appropriately controlling the torque of servo brakes based on RT. We propose a human adaptive motion control algorithm that changes the apparent dynamics to adapt to user difficulties, and an environmentally adaptive motion control algorithm, which incorporates environmental information to provide obstacle/step avoidance and gravity compensation functions. The proposed control algorithms are experimentally applied to the RT walker to test their validity. 相似文献
93.
94.
Kentaro Yanagihara Jumpei Taketsugu Kiyoshi Fukui Shigeru Fukunaga Shinsuke Hara Ken-ichi Kitayama 《Wireless Personal Communications》2007,40(3):401-415
In this paper, we propose a new energy efficient clustering scheme with transmission power control named “EACLE” (Energy-Aware
CLustering scheme with transmission power control for sEnsor networks) for wireless sensor networks, which are composed of
the following three components; “EACLE clustering” is a distributed clustering method by means of transmission power control,
“EACLE routing” builds a tree rooted at a sink node and sets the paths from sensor nodes taking energy saving into consideration,
and “EACLE transmission timing control” changes the transmission timing with different levels of transmission power to avoid
packet collisions and facilitates packet binding.
With an indoor wireless channel model which we obtained from channel measurement campaigns in rooms and corridors and an energy
consumption model which we obtained from a measurement of a chipset, we performed computer simulations to investigate the
performance of EACLE in a realistic environment. Our simulation results indicate that EACLE outperforms a conventional scheme
such as EAD (Energy-Aware Data-centric routing) in terms of communication success rate and energy consumption. Furthermore,
we fully discuss the impact of transmission power and timing control on the performance of EACLE. 相似文献
95.
Yoshinobu Murakawa Motoaki Hara Hiroyuki Oguchi Yuichiro Hamate Hiroki Kuwano 《Microsystem Technologies》2013,19(8):1255-1259
This paper describes a new type hydrogen sulfide (H2S) gas sensor using ionic liquid (IL). In this sensor, a reservoir for the IL was integrated on a surface acoustic wave (SAW) resonator. The IL serves as an absorber for H2S gas. Mass change due to this absorption is detected as shift in the resonant frequency. In this study, we fabricated and demonstrated the sensor using the lithium niobate (LiNbO3) SAW resonator with the resonant frequency of 38 MHz. The integrated reservoir was filled by the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]-[PF6]). As an experimental result, we observed the linear correlation between the frequency-shift and the exposure time of the sensor to the H2S gas. 相似文献
96.
This paper proposes a new method of parameter space design for robust control synthesis which guarantees the real stability radius constraint, accomplished by using Quantifier Elimination (QE). We aim at practicality by employing the scheme to combine the Sign Definite Condition (SDC) and a special QE algorithm using the Sturm-Habicht sequence. The validity of our approach is confirmed by several design examples. 相似文献
97.
98.
A relationship between real poles and real zeros of SISO (single-input, single-output) sampled data systems is presented, which is independent of the sampling period. The relation is stated in terms of a parity property involving the number of real zeros between any two real poles. This property allows the investigation of conditions for the preservation of stable or unstable zeros under sampling. A sufficient condition for stability of a sampled system with a continuous-time plant having all real zeros, and a sufficient condition for instability of a two-sampled system with an unstable plant is developed 相似文献
99.
Influence of the methyl group on the dielectric constant of boron carbon nitride films containing it
Hidemitsu Aoki Takuro Masuzumi Makoto Hara Zhiming Lu Daisuke Watanebe Chiharu Kimura Takashi Sugino 《Diamond and Related Materials》2010,19(12):1437-1440
LSI interconnect insulators made using low dielectric constant (low-k) materials are required for high performance devices with a small RC delay. We investigated a boron carbon nitride film containing the methyl group (Me–BCN) using tris-di-methyl-amino-boron (TMAB: B[N(CH3)2]3) gas as a low-k material. In addition, we studied the influence of the methyl group on the dielectric constant (k-value) and the properties of the Me–BCN films. It was found that the k-value of the Me–BCN films decreases with increasing number of C–H bonds due to the methyl group (CH3). The number of O–H bonds due to water incorporation is suppressed by increasing the number of C–H bonds. Consequently, we suggested that a lower k-value can be realized by the suppression of water invasion by a hydrophobic surface due to methyl bonds. Thus, the control of the methyl group is important to achieve a low-k material using Me–BCN films. 相似文献
100.
A Suminoe A Matsuzaki N Kinukawa T Inamitsu T Tajiri S Suita T Hara 《Canadian Metallurgical Quarterly》1999,134(2):178-184
OBJECTIVE: To evaluate the association of somatic growth from birth through diagnosis with the development of childhood cancer. METHODS: The weights and heights of 1718 children with cancers were determined and converted into standard deviation (SD) scores, both at birth and at diagnosis, by using the means and SD values of the general population. RESULTS: Among patients with neuroblastoma and acute lymphoblastic leukemia, the percentages of children with body weight and height over mean + 2 SDs were significantly higher at diagnosis than the expected value in the general population. The percentage of children with neuroblastoma and body weight over mean + 2 SD increased significantly from birth through diagnosis (P =.04). Although the medians of weight SD scores decreased from birth through diagnosis in patients with representative cancers except for neuroblastoma, the value significantly increased in patients with neuroblastoma diagnosed before 1 year of age (P =.03), especially in those whose cancer was detected by mass screening at 6 months of age (P <.01). CONCLUSIONS: Rapid somatic growth from birth through diagnosis in patients with neuroblastoma diagnosed before 1 year of age suggests a possible involvement of certain growth factors in these patients. 相似文献