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991.
Interlayer Pd for the Li/Pd/Cu neutron target for BNCT (boron neutron capture therapy) was characterized after 0.1-5 keV H2^+ irradiation by XAFS (X-ray absorption fine structure) technique, and following conclusions were derived: (1) from the XAFS observation of white line of Pd, remarkable Pd L3 edge jump was found in 1.1-3 times higher than before irradiation in low irradiation fluence; (2) this fact indicates increase of hole density in Pd 4d-band, whereas, no change was observed for XASF spectra of Ag sample under the same irradiation conditions; (3) remarkable Pd L3 edge shift of 0.12-0.66 eV was also found with increase of H2+ irradiation energy in low fluence, and drastically decreased after peak in high irradiation energy and fluence; (4) implanted protons deposited in Pd as negative under the balance of electron population enhanced by proton irradiation and charge transfer. 相似文献
992.
Berkan Dulek Sinan Gezici Ryo Sawai Ryota Kimura 《Wireless Personal Communications》2014,77(1):151-172
An upper bound is derived on the capacity of a cognitive radio system by considering the effects of path loss and log-normal shadowing simultaneously for a single-cell network. Assuming that the cognitive radio is informed only of the shadow fading between the secondary (cognitive) transmitter and primary receiver, the capacity is achieved via the water-filling power allocation strategy under an average primary signal to secondary interference plus noise ratio loss constraint. Contrary to the perfect channel state information requirement at the secondary system (SS), the transmit power control of the SS is accomplished in the absence of any path loss estimates. For this purpose, a method for estimating the instantaneous value of the shadow fading is also presented. A detailed analysis of the proposed power adaptation strategy is conducted through various numerical simulations. 相似文献
993.
T Ogawa W Linz M Stevenson BG Bruneau ML Kuroski de Bold JH Chen H Eid BA Sch?lkens AJ de Bold 《Canadian Metallurgical Quarterly》1996,93(11):2059-2067
BACKGROUND: In hypertension with cardiac hypertrophy, the specific contributions to increased production of the cardiac natriuretic peptides (NP) atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) by load and the hypertrophic process are not known. In the present work we determine ANF and BNP synthesis and secretion in the aortic-banded rat treated with dosage schedules of the ACE inhibitor ramipril that result in the prevention or regression of both hypertension and hypertrophy (high dosage) or in the prevention or regression of hypertrophy alone with persistent hypertension (low dosage). Myosin heavy chain (MHC) isoform switch was studied as an indicator of ventricular cardiocyte hypertrophy as well as the levels of collagen III mRNA as a measure of changes in extracellular matrix. METHODS AND RESULTS: Ramipril was administered for 6 weeks just after suprarenal aortic banding, or rats were banded for 6 weeks, after which ramipril was administered during the following 6 weeks. Banding caused an increase in blood pressure, left ventricular weight-to-body weight ratio, plasma and ventricular NP, ventricular NP mRNA, collagen III, and beta-MHC mRNA. Ramipril at 1 mg/kg normalized all these parameters while ramipril at 10 micrograms/kg normalized left ventricular weight-to-body weight ratio but not blood pressure. Plasma and ventricular NP content and mRNA levels were partially normalized by ramipril (10 micrograms/kg). Ramipril (10 micrograms/kg) prevented increased collagen III mRNA levels but did not affect beta-MHC mRNA levels. CONCLUSIONS: (1) NP production and secretion in aortic-banded rats are independently related to increased blood pressure and hypertrophy. (2) A load-dependent component is more important than a load-independent component in regulating left ventricular NP production. (3) ANF production is more sensitive than BNP production to the load-independent component. (4) Low-dose ramipril treatment reverses hypertrophy and the increased collagen III expression but does not reverse the increased beta-MHC isoform expression, suggesting that these are independently regulated processes. (5) Aortic banding and ACE inhibition do not affect atrial NP production and content. 相似文献
994.
T Yamagami H Sugiyama K Inoue H Ogawa T Tatekawa M Hirata T Kudoh T Akiyama A Murakami T Maekawa 《Canadian Metallurgical Quarterly》1996,87(7):2878-2884
We have previously reported expression of WT1 in acute leukemia. To elucidate its biological significance, we examined the effect of the suppression of the WT1 expression by WT1 antisense oligomers on the growth of the leukemic cells expressing WT1. When 20 different WT1 antisense (AS) oligomers covering from the 5' cap sites of the WT1 gene to the 3' end were examined for the inhibitory effect on the growth of K562 cells expressing WT1, four WT1 AS oligomers inhibited the cell growth, whereas WT1 sense and random sequence oligomers had no effect on the cell growth of K562. Moreover, WT1 AS oligomers significantly inhibited the growth of the clonogenic cells of fresh leukemic cells in six of 14 patients with acute myeloid leukemia, in one of two patients with chronic myelogenous leukemia (CML) chronic phase, and in one of one patient with CML blastic crisis. However, these oligomers did not inhibit normal colony-forming unit-granulocyte-macrophage. Western blot analysis clearly demonstrated the significant reduction in the WT1 protein levels in the K562 and fresh leukemic cells that were treated with the WT1 AS oligomers, confirming that the inhibitory effect of the WT1 AS oligomers on the cell growth operates via the reduction in the WT1 protein levels. These results show that WT1 plays an important role in leukemogenesis. 相似文献
995.
H. Ogawa A. Mizuno H. Hoko H. Ishikawa Y. Fukui 《Journal of Infrared, Millimeter and Terahertz Waves》1990,11(6):717-726
A 110 GHz superconductor insulator superconductor (SIS) tunnel junction receiver has been developed and used in regular astronomical observations on the 4m radio telescope at the Department of Astrophysics, Nagoya University. The SIS junction consists of a sandwich structure of Nb/AlOx/Nb, and is cooled to 4.2K with a closed cycle He-gas refrigerator. The receiver exhibits a best double side band noise temperature of 23±2 K at 110GHz. Additional measurements at 98–115 GHz indicate that the receiver has a good response over this input frequency range. 相似文献
996.
The use of ligand-binding methods to study neurotransmitter-receptor sites has made its impact on almost all aspects of biological pursuits including research on aging and neurodegenerative diseases. In the past, most of the research in biochemical gerontology has largely centered around changes in various neurotransmitters and enzymatic activities. The molecular basis of aging and neurodegeneration at the level of neurotransmitter-receptor interactions has been highly appreciated in the last two decades as a result of receptor binding studies. It is now possible to obtain information about the regional distribution of neurotransmitter receptors in the brain, the pharmacological and biochemical characteristics of these sites, and the functional interrelationships between different neuronal systems in normal and pathological conditions. The passage of time after maturity is accompanied by measurable physiologic decline in virtually all systems. It is the aim of this work to discuss the practical aspects of neurotransmitter and/or drug (ligand)-receptor binding studies, highlighting some examples of their applications to geriatric neuropharmacology research, with special consideration to learning impairment and memory loss in normal and in pathological aging processes. 相似文献
997.
Developmental changes in the effects of arachidonic acid (AA) on N-methyl-D-aspartate (NMDA) receptor-mediated currents were investigated in acutely dissociated rat cortical neurones using a whole-cell patch-clamp method. AA potentiated peak NMDA currents (INMDA) in a concentration-dependent manner. Potentiation by AA was greater at 2-4 postnatal days (P2-4) than at P7-8 and P15-18. Indomethacin reduced the potentiating effect of AA only at P2-4, while caffeic acid and baicalein showed no apparent effect, indicating that metabolites of the cyclooxygenase pathway contribute to INMDA potentiation at P2-4. Staurosporine diminished the potentiation of INMDA at P2-4, suggesting that protein kinase C might participate in the effect of AA. These findings suggest that the greater potentiation of INMDA by AA at P2-4 has a different underlying mechanism from effects seen at P7-8 or older. 相似文献
998.
Ogawa K. Kurata M. Suzuki H. Ichiyanagi N. Nakayama K. Inoue T. Kasuya M. Iwata Z. 《Power Delivery, IEEE Transactions on》1989,4(1):34-44
Tricresyl phosphate (TCP), a phosphate ester with fire-resistant and insulating properties, is proposed as a cable cooling medium. A field test was performed with a 275 kV internally-oil-cooled, oil-filled (OF) power cable system using TCP, and it was ascertained that the cable system meets requirements for ease of installation, cooling characteristics, and long-term stability of the cable and the long-term stability of the cable and the TCP. The series of tests has demonstrated the practicality of the cable system 相似文献
999.
Dosaka K. Yamazaki A. Watanabe N. Abe H. Ohtani J. Ogawa T. Ishihara K. Kumanoya M. 《Solid-State Circuits, IEEE Journal of》1996,31(4):537-545
This paper describes a system integrated memory with direct interface to CPU which integrates an SRAM, a DRAM, and control circuitry, including a tag memory (TAG). This memory realizes a computer system without glue chips, and thus enables a computer system which is low cost, low power, and compact size, but still with sufficient performance. Also fast clock cycle time and access time is realized using a newly proposed clock driver and internal signal generator. This memory is fabricated with a quad-polysilicon double-metal 0.55-μm CMOS process which is the same as used in a conventional 16-Mb DRAM. The chip size of 145.3 mm2 is only a 12% increase over the conventional 16-Mb DRAM. The maximum operating frequency is 90-MHz and the operating current at cache-bit is 156-mA. This memory is suitable for various types of computer systems such as personal digital assistants (PDA's), personal computer systems, and embedded controller applications 相似文献
1000.
T. Idehara Y. Shimizu S. Makino K. Ichikawa T. Tatsukawa I. Ogawa G. F. Brand 《Journal of Infrared, Millimeter and Terahertz Waves》1997,18(2):391-403
Amplitude modulation of gyrotron by a small modulation of the anode voltage is calculated using an energy transfer formula. Experimental measurements using a submillimeter wave gyrotron are in good agreement. One hundred percent modulation of the output at frequencies up to several hundred kilohertz has been achieved with anode modulation levels of only a few percent. Numerical calculations lend further support to the experimental results. 相似文献