102 research outputs found

    Substellar Companions to Evolved Intermediate-Mass Stars: HD 145457 and HD 180314

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    We report the detections of two substellar companions orbiting around evolved intermediate-mass stars from precise Doppler measurements at Subaru Telescope and Okayama Astrophysical Observatory. HD 145457 is a K0 giant with a mass of 1.9 M_sun and has a planet of minimum mass m_2sini=2.9 M_J orbiting with period of P=176 d and eccentricity of e=0.11. HD 180314 is also a K0 giant with 2.6 M_sun and hosts a substellar companion of m_2sin i=22 M_J, which falls in brown-dwarf mass regime, in an orbit with P=396 d and e=0.26. HD 145457 b is one of the innermost planets and HD 180314 b is the seventh candidate of brown-dwarf-mass companion found around intermediate-mass evolved stars.Comment: 16 pages, 4 figures, accepted for publication in PAS

    Planetary Companions to Evolved Intermediate-Mass Stars: 14 Andromedae, 81 Ceti, 6 Lyncis, and HD 167042

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    We report on the detection of four extrasolar planets orbiting evolved intermediate-mass stars from a precise Doppler survey of G and K giants at Okayama Astrophysical Observatory. All of the host stars are considered to be formerly early F-type or A-type dwarfs when they were on the main sequence. 14 And (K0 III) is a clump giant with a mass of 2.2 M_solar and has a planet of minimum mass m_2sin i=4.8 M_Jup in a nearly circular orbit with a 186 day period. This is one of the innermost planets around evolved intermediate-mass stars and such planets have only been discovered in clump giants. 81 Cet (G5 III) is a clump giant with 2.4 M_solar hosting a planet of m_2sin i=5.3 M_Jup in a 953 day orbit with an eccentricity of e=0.21. 6 Lyn (K0 IV) is a less evolved subgiant with 1.7 M_solar and has a planet of m_2sin i=2.4 M_Jup in a 899 day orbit with e=0.13. HD 167042 (K1 IV) is also a less evolved star with 1.5 M_solar hosting a planet of m_2sin i=1.6 M_Jup in a 418 day orbit with e=0.10. This planet was independently announced by Johnson et al. (2008, ApJ, 675, 784). All of the host stars have solar or sub-solar metallicity, which supports the lack of metal-rich tendency in planet-harboring giants in contrast to the case of dwarfs.Comment: 23 pages, 6 figures, accepted for publication in PAS

    Embedded DRAM using c-axis-aligned crystalline In-Ga-Zn oxide FET with 1.8V-power-supply voltage

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    An embedded memory using c-axis aligned crystalline In-Ga-Zn oxide (CAAC-IGZO) FETs with an extremely low off-state current on the order of yoctoamperes (yA) (yocto- is a metric prefix denoting a factor of 10-24) is known as a potential next-generation memory [1][2]. A dynamic oxide semiconductor RAM (DOSRAM), where each memory cell is composed of one CAAC-IGZO FET and one capacitor, enables long data retention and long interval of refresh operations with an advantage of extremely low off-state current of the CAAC-IGZO FET. However, negative backgate voltage (Vbg) and word-line driving voltages of 0/3.3 V (VSSL/VDDH) had been required for an access transistor of the memory cell to satisfy high on-state current and low off-state current. This work shows that DOSRAM operates with 1.8 V-power supply voltage by using a novel driving method. Figure 1 shows Vg-Id performance of a CAAC-IGZO FET used as a cell transistor. The threshold voltage (Vth) of the CAAC-IGZO FET is controlled by changing a level of Vbg, whereas Vth of the Si FET is controlled by channel doping. Figure 2 shows a block diagram of a prototyped DOSRAM. The refresh rate in DOSRAM mainly depends on the leakage current of cell transistors. To reduce the refresh rate to once an hour, the off-state current of the cell transistors on a non-selected word line needs to be reduced to 200 zeptoamperes (zA) per FET (zepto- is a metric prefix denoting a factor of 10-21) or lower at 85C. The required Vbg is -7.0 V to achieve such an off-state current at Vg 0 V, for example. To obtain approx. 100 MHz-driving frequency, the required on-state current is at least several microamperes. The voltage level difference in the word line, VDDH VSSL, is a factor that determines the on-state current, and in this work is fixed to 3.3 V so that the combination of Vbg and the word line voltage is optimized. The application of negative voltage to the word line enables the leakage current of the cell transistor to be maintained low even when Vbg is increased. For example, whereas the existing driving method meets the above off-state current value with Vbg -7.0 V and the VSSL 0 V, the novel driving method meets the value with Vbg 0 V and VSSL -1.5 V. In the novel driving method, VDDH 1.8 V. There has been a report of a reduction in leakage current of a memory cell by application of negative voltage to a top gate in DRAM using Si CMOS [3]. In contrast to it, DOSRAM including CAAC-IGZO FETs with L 60 nm has a leakage current of 200 zA or lower, which is 7-digit lower than that of the DRAM using Si CMOS, and enables longer data retention. The evaluation results of the prototyped DOSRAM verify that a reduction in power-supply voltage from 3.3 V to 1.8 V is possible in terms of operation and data retention. This suggests a highly compatible and efficient configuration of an embedded DRAM and a logic circuit where signals can be transmitted with low VDD. References [1] S. H. Wu, et al., IEEE Symp. VLSI Tech., pp. 166-167, 2017. [2] T. Ishizu, et al., IEEE Symp. VLSI Cir., pp. 162-163, 2017. [3] F. Hamzaoglu et al., IEEE Journal of Solid-State Circuits, vol. 50, no. 1, pp. 150-157, Jan. 2015

    Potential of a Novel Chemical Compound Targeting Matrix Metalloprotease-13 for Early Osteoarthritis: An In Vitro Study

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    Osteoarthritis is a progressive disease characterized by cartilage destruction in the joints. Matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) play key roles in osteoarthritis progression. In this study, we screened a chemical compound library to identify new drug candidates that target MMP and ADAMTS using a cytokine-stimulated OUMS-27 chondrosarcoma cells. By screening PCR-based mRNA expression, we selected 2-(8-methoxy-2-methyl-4-oxoquinolin-1(4H)-yl)-N-(3-methoxyphenyl) acetamide as a potential candidate. We found that 2-(8-methoxy-2-methyl-4-oxoquinolin-1(4H)-yl)-N-(3-methoxyphenyl) acetamide attenuated IL-1 beta-induced MMP13 mRNA expression in a dose-dependent manner, without causing serious cytotoxicity. Signaling pathway analysis revealed that 2-(8-methoxy-2-methyl-4-oxoquinolin-1(4H)-yl)-N-(3-methoxyphenyl) acetamide attenuated ERK- and p-38-phosphorylation as well as JNK phosphorylation. We then examined the additive effect of 2-(8-methoxy-2-methyl-4-oxoquinolin-1(4H)-yl)-N-(3-methoxyphenyl) acetamide in combination with low-dose betamethasone on IL-1 beta-stimulated cells. Combined treatment with 2-(8-methoxy-2-methyl-4-oxoquinolin-1(4H)-yl)-N-(3-methoxyphenyl) acetamide and betamethasone significantly attenuated MMP13 and ADAMTS9 mRNA expression. In conclusion, we identified a potential compound of interest that may help attenuate matrix-degrading enzymes in the early osteoarthritis-affected joints

    Stent-Related Adverse Events as Related to Dual Antiplatelet Therapy in First- vs Second-Generation Drug-Eluting Stents

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    [Background] There are limited data on the long-term stent-related adverse events as related to the duration of dual antiplatelet therapy (DAPT) in second-generation (G2) drug-eluting stents (DES) compared with first-generation (G1) DES. [Objectives] This study sought to compare the long-term stent-related outcomes of G2-DES with those of G1-DES. [Methods] The study group consisted of 15, 009 patients who underwent their first coronary revascularization with DES from the CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Grafting) Registry Cohort-2 (first-generation drug-eluting stent [G1-DES] period; n = 5, 382) and Cohort-3 (second-generation drug eluting stent [G2-DES] period; n = 9, 627). The primary outcome measures were definite stent thrombosis (ST) and target vessel revascularization (TVR). [Results] The cumulative 5-year incidences of definite ST and TVR were significantly lower in the G2-DES group than in the G1-DES group (0.7% vs 1.4%; P < 0.001; and 16.2% vs 22.1%; P < 0.001, respectively). The lower adjusted risk of G2-DES relative to G1-DES for definite ST and TVR remained significant (HR: 0.53; 95% CI: 0.37-0.76; P < 0.001; and HR: 0.74; 95% CI: 0.68-0.81; P < 0.001, respectively). In the landmark analysis that was based on the DAPT status at 1 year, the lower adjusted risk of on-DAPT status relative to off-DAPT was significant for definite ST beyond 1 year in the G1-DES stratum (HR: 0.42; 95% CI: 0.24-0.76; P = 0.004) but not in the G2-DES stratum (HR: 0.66; 95% CI: 0.26-1.68; P = 0.38) (Pinteraction = 0.14). [Conclusions] G2-DES compared with G1-DES were associated with a significantly lower risk for stent-related adverse events, including definite ST and TVR. DAPT beyond 1 year was associated with a significantly lower risk for very late ST of G1-DES but not for that of G2-DES

    ナルト ワカメ ノ ヨウショク ギジュツ カイハツ フキュウ ニ コウケン シタ ナルト ノ リョウシ : チュウガッコウ リカ カガク ギジュツ ノ ハッテン ト ニンゲン セイカツ ノ コウジョウ ノ チイキ キョウザイ カイハツ ノ タメ ニ

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    本論文では鳴門におけるワカメ養殖技術の開発・普及に関わった方々に対して聞き取り調査を行い,ワカメ養殖の経緯と先人の努力を記録として残すことを目的とする。 調査の結果,漁民の生活の向上のために努力した先人のワカメ養殖にかける熱意が明らかとなった。今後,このような地域に密着した教材を使うことにより,科学技術の発展が人間生活の向上に役立っていることを実感する学習の展開が可能である。The aim of interviewing anyone who had been involved in the technological development and dissemination of “ Wakame” seaweed aquaculture in Naruto, was to record for posterity our ancestor’s efforts and history of Wakame seaweed aquaculture. As the investigation went on, the surge of enthusiasm for our wakame seaweed farming ancestors, who were striving to improve the life of fishermen, became clear as the result.Next, we realized that using educational materials for development of science and technology in close contact with such areas, contributes to render improvement of human life possible
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