258 research outputs found

    Accumulation and depletion layer thicknesses in organic field effect transistors

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    We present a simple but powerful method to determine the thicknesses of the accumulation and depletion layers and the distribution curve of injected carriers in organic field effect transistors. The conductivity of organic semiconductors in thin film transistors was measured in-situ and continuously with a bottom contact configuration, as a function of film thickness at various gate voltages. Using this method, the thicknesses of the accumulation and depletion layers of pentacene were determined to be 0.9 nm (VG=-15 V) and 5 nm (VG=15 V).Comment: 3 pages, 4 figures, Jap. J. Appl. Phys. in pres

    A cyclonic eddy train and poleward heat transport in the Australian-Antarctic Basin

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Thu. 5 Dec. / 2F Auditorium , National Institute of Polar Researc

    Performance of Mixture-Ratio-Controlled Hybrid Rockets for Nominal Fuel Regression

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    This paper discusses the impacts of oxidizer-to-fuel mass ratio (O/F) shifts on the flight performance of single-stage sounding rockets using the flight simulations of three scales of O/F-controlled and O/F-uncontrolled hybrid rockets under a nominal fuel regression behavior without uncertainty. The flight simulation code includes three factors dependent on the O/F: thermodynamic states of the burned gas (theoretical Isp), shifts in c∗ efficiency, and nozzle throat erosion. In the flight simulations, a thrust control law was applied to increase the apogee and evaluate the effects of O/F shifts in the thrust curve including throttling. For the best cases in each scale, O/F-controlled hybrid rockets slightly improved the performance by 2.03–2.42% in the averaged specific impulse. However, the performance of the O/F-controlled sounding rockets is essentially the same as the O/F-uncontrolled type under the median regression behavior: especially when considering the slight increases in the mass and complexity of the oxidizer feed system needed for O/F control. Considerable scale effects on the throat erosion and theoretical Isp were observed, but that of the c∗ efficiency was negligible. The improvement of the theoretical Isp was the primary contributor to flight performance, which was responsible for a larger than 70% share in the total Isp increase. The second largest contribution was the improvement of the c∗ efficiency with a share of 21.8–24.3%. The O/F control gave an improvement of throat erosion corresponding to 5.75% in the total Isp increase for the smallest scale; but, with increasing of the scale, the throat area increase ratio became small so that the throat erosion improvement contribution was reduced to 1.21%

    Performance of Mixture-Ratio-Controlled Hybrid Rockets under Uncertainties in Fuel Regression

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    This paper evaluates various sources of oxidizer to fuel mass ratio (O/F) shifts in hybrid rockets and paths (physical phenomena) through which these O/F shifts affect flight performance. Moreover, the performance increase of O/F control in hybrid rockets is evaluated. Vertical launches of O/F uncontrolled and O/F controlled of hybrid sounding rockets were simulated under two uncertainty models of fuel regression behavior based on experimental data: a) systematic errors with a constant deviation within ±3σ±3σ and 2) random errors subject to a probability distribution. These simulations included all sources of O/F shifts that originated in the fuel regression behavior and all paths through which the O/F shifts affect flight performance. Residual propellant mass and decreases in specific impulse are found to be the dominant causes of performance loss under both uncertainty models. For both cases 1 and 2, the O/F-controlled hybrid rockets maintained the performance expected under nominal fuel regression behavior, whereas the O/F-uncontrolled hybrid rockets had a lower performance by upwards of 6.69 and 4.06% in ΔVΔV for cases 1 and 2, respectively. For case 2, 3008 flight simulations revealed that the worst case of the O/F-controlled hybrid rocket had a 4.06 to 4.49% larger ΔVΔV and 10.5 to 13.3% higher apogee than that of the O/F-uncontrolled hybrid rocket, and that the O/F-uncontrolled hybrid rocket had a 6.61 times larger standard deviation in ΔVΔV. These results mean that the elimination O/F shift in hybrid rockets significantly improves performance, as well as the accuracy and reliability of performance predictions

    Acquisition of Periodic Events with Person Attributes

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    In this paper, we aim to acquire “periodic events” that represent significant actions that are happened by groups of people in particular seasons or timing. Recently, the importance of knowledge acquisition is increasing. Many studies about human action knowledge and temporal commonsense knowledge have been carrying out. We need a dataset to acquire periodic events. However, manually building the dataset with human attribute labels is costly. Therefore, we construct a human attribute classifier of Twitter users and create a large labeled tweets dataset automatically. Periodic events with specific human attributes are collected with our proposed method. Finally, we obtained commonsense event knowledge; e.g., “Students often go to college at 1 P.M.” and “Workers often work overtime on weekdays”.International Conference on Asian Language Processing (IALP 2020), 4-6 December, 2020, Kuala Lumpur, Malaysia(新型コロナ感染拡大に伴い、オンライン開催に変更

    Secreted factors from adipose tissue-derived mesenchymal stem cells suppress oxygen/glucose deprivation-induced cardiomyocyte cell death via furin/PCSK-like enzyme activity

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    AbstractClinical application of mesenchymal stem cells (MSCs) represents a potential novel therapy for currently intractable deteriorating diseases or traumatic injuries, including myocardial infarction. However, the molecular mechanisms of the therapeutic effects have not been precisely revealed. Herein, we report that conditioned media (CM) from rat adipose tissue-derived MSCs (ASCs) protected adult cardiomyocytes from oxygen/glucose deprivation (OGD)-induced cell death. We focused on furin/PCSK protease activity in ASC-CM because many therapeutic factors of MSCs and soluble cardioprotective factors include the PCSK cleavage site. We found that recombinant furin protected cardiomyocytes from OGD-induced cell death. The ASC-CM had potent furin/PCSK protease activity and the cardioprotective effect of the CM from ASCs in the OGD-assay was abolished by an inhibitor of the furin/PCSK-like enzyme. Microarray analysis and Western blot analysis showed PCSK5A, the secreted type of PCSK5, is the most abundantly secreted PCSK among 7 PCSK family members in ASC. Finally, knockdown of PCSK5A in ASCs decreased both the furin/PCSK protease activity and cardioprotective activity in the CM. These findings indicate an involvement of furin/PCSK-type protease(s) in the anti-ischemic activity of ASCs, and suggest a new mechanism of the therapeutic effect of MSCs

    Structure of Meridional Circulation in Southern Ocean captured by long term Mooring

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

    The Use of an Intermaxillary Fixation Screw for Mandibular Setback Surgery

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    金沢大学医学部附属病院歯科口腔外科Purpose: To assess skeletal stability after mandibular setback surgery with and without an intermaxillary fixation (IMF) screw. Patients and Methods: The subjects were 40 patients with mandibular prognathism. The subjects underwent sagittal split ramus osteotomy with titanium plate fixation and were divided into 2 groups, 1 with and 1 without an IMF screw. A lateral cephalogram was done preoperatively, immediately after surgery, and 1 month, 3 months, and 6 months postoperatively. The 2 groups were then compared statistically. Results: In the comparison of the time-course change between the 2 groups with repeated measure analysis of variance, there were significant differences in occlusal plane (between subjects, F = 2.517; df = 4; P = .0437) and convexity (between subjects, F = 4.048; df = 4; P = .0038). However, there was no significant difference in the other measurements. Conclusion: This study suggested that in most measurements, there was no significant difference between 2 groups with and without an IMF screw in time-course skeletal change. However, use of IMF screws was helpful for orthognathic surgery as a rigid anchor of IMF. © 2007 American Association of Oral and Maxillofacial Surgeons

    浸潤および血管新生を通しての人肝細胞癌の進行におけるケラチン19分子の役割

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    BACKGROUND: Keratin (K) 19-positive hepatocellular carcinoma (HCC) is well known to have a higher malignant potential than K19-negative HCC: However, the molecular mechanisms involved in K19-mediated progression of HCC remain unclear. We attempted to clarify whether K19 directly affects cell survival and invasiveness in association with cellular senescence or epithelial-mesenchymal transition (EMT) in K19-positive HCC. METHODS: K19 expression was analysed in 136 HCC surgical specimens. The relationship of K19 with clinicopathological factors and survival was analysed. Further, the effect of K19 on cell proliferation, invasion, and angiogenesis was examined by silencing K19 in the human HCC cell lines, HepG2, HuH-7, and PLC/PRF/5. Finally, we investigated HCC invasion, proliferation, and angiogenesis using K19-positive HCC specimens. RESULTS: Analysis of HCC surgical specimens revealed that K19-positive HCC exhibited higher invasiveness, metastatic potential, and poorer prognosis. In vitro experiments using the human HCC cell lines revealed that K19 silencing suppressed cell growth by inducting apoptosis or upregulating p16 and p27, resulting in cellular senescence. In addition, transfection with K19 siRNA upregulated E-cadherin gene expression, significantly inhibited the invasive capacity of the cells, downregulated angiogenesis-related molecules such as vasohibin-1 (VASH1) and fibroblast growth factor 1 (FGFR1), and upregulated vasohibin-2 (VASH2). K19-positive HCC specimens exhibited a high MIB-1 labelling index, decreased E-cadherin expression, and high microvessel density around cancer foci. CONCLUSION: K19 directly promotes cancer cell survival, invasion, and angiogenesis, resulting in HCC progression and poor clinical outcome. K19 may therefore be a novel drug target for the treatment of K19-positive HCC.博士(医学)・乙第1399号・平成29年3月15日© The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
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