146 research outputs found

    c-trie++: A Dynamic Trie Tailored for Fast Prefix Searches

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    Given a dynamic set KK of kk strings of total length nn whose characters are drawn from an alphabet of size σ\sigma, a keyword dictionary is a data structure built on KK that provides locate, prefix search, and update operations on KK. Under the assumption that α=w/lgσ\alpha = w / \lg \sigma characters fit into a single machine word ww, we propose a keyword dictionary that represents KK in nlgσ+Θ(klgn)n \lg \sigma + \Theta(k \lg n) bits of space, supporting all operations in O(m/α+lgα)O(m / \alpha + \lg \alpha) expected time on an input string of length mm in the word RAM model. This data structure is underlined with an exhaustive practical evaluation, highlighting the practical usefulness of the proposed data structure, especially for prefix searches - one of the most elementary keyword dictionary operations

    Studies on the Effect of Radio Frequency Field in a Cusp-Type Charge Separation Device for Direct Energy Conversion

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    In D-3He fusion power generation, an application of direct energy conversion is expected in which separation of charged particles is necessary. A cusp-type direct energy converter (CuspDEC) was proposed as a charge separation device, but its performance was degraded for a high density plasma. The goal of the present study is to establish an additional method to assist charge separation by using a nonlinear effect of a radio frequency (rf) electric field. Following to the previous study, we experimentally examine the effect of an rf field to electron motion in a CuspDEC device. Two ring electrodes were newly installed in a CuspDEC simulator and the current flowing into the electron collector located in the line cusp region was measured on an rf field application. The significant variation in the current was found, and an improvement of the charge separation can be expected by using the phenomenon appropriately

    Temperature-dependent magnetoresistance effects in FeSi/FeSi/FeSi trilayered spin valve junctions

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    Fe3Si/FeSi2/Fe3Si trilayered junctions were fabricated by facing targets direct-current sputtering combined with a mask method, and the spin valve signals of the junctions were studied in the temperature range from 50 to 300 K. Whereas the magnetoresistance ratio of giant magnetoresistance and tunnel magnetoresistance junctions monotonically increases with decreasing temperature, that of our samples has the maximum value around 80 K and decreases with decreasing temperature at lower than 80 K, which might be due to an increase in the electrical conductivity mismatch between the metallic Fe3Si layers and semiconducting FeSi2 interlayer in the low temperature range.Asia-Pacific Conference on Semiconducting Silicides and Related Materials — Science and Technology Towards Sustainable Electronics (APAC Silicide 2016), July 16-18, 2016, Fukuoka, Japa

    Outcomes after stepwise ablation for persistent atrial fibrillation in patients with heart failure

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    AbstractBackgroundThere is limited data regarding the outcomes after stepwise ablation for persistent atrial fibrillation (AF) in patients with heart failure (HF).Methods and resultsPatients without structural heart disease undergoing stepwise ablation for persistent AF (continuous AF≤1 year) were studied (n=108; age, 61±10 years) and 32 patients had a history of HF. The HF patients were further grouped on the basis of left ventricular ejection fraction (LVEF)≤45% (n=15) and >45% (n=17). During a median follow-up period of 2.2 years, repeated ablations were necessary in 65 patients. The proportion of patients that were arrhythmia free 1 year after the last ablation was 67% in patients with LVEF≤45%, 86% in LVEF>45%, and 91% in no HF (p=0.0009). In patients with LVEF≤45%, the AF burden was reduced to less than one paroxysmal episode per month, and patients with and without recurrences both showed significant increases in LVEF over the follow-up period (38±7% to 60±10% and 37±6% to 53±10%, respectively).ConclusionsHF patients with LVEF≤45% had lower chances to remain free from arrhythmias after stepwise ablation for persistent AF than those with LVEF>45%. Nevertheless, LVEF also improved in patients with recurrences, reflecting the observed reduction in AF burden and emphasizing the benefits of ablation

    Management of Hepatocellular Carcinoma in Japan : JSH Consensus Statements and Recommendations 2021 Update

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    The Clinical Practice Manual for Hepatocellular Carcinoma was published based on evidence confirmed by the Evidence-based Clinical Practice Guidelines for Hepatocellular Carcinoma along with consensus opinion among a Japan Society of Hepatology (JSH) expert panel on hepatocellular carcinoma (HCC). Since the JSH Clinical Practice Guidelines are based on original articles with extremely high levels of evidence, expert opinions on HCC management in clinical practice or consensus on newly developed treatments are not included. However, the practice manual incorporates the literature based on clinical data, expert opinion, and real-world clinical practice currently conducted in Japan to facilitate its use by clinicians. Alongside each revision of the JSH Guidelines, we issued an update to the manual, with the first edition of the manual published in 2007, the second edition in 2010, the third edition in 2015, and the fourth edition in 2020, which includes the 2017 edition of the JSH Guideline. This article is an excerpt from the fourth edition of the HCC Clinical Practice Manual focusing on pathology, diagnosis, and treatment of HCC. It is designed as a practical manual different from the latest version of the JSH Clinical Practice Guidelines. This practice manual was written by an expert panel from the JSH, with emphasis on the consensus statements and recommendations for the management of HCC proposed by the JSH expert panel. In this article, we included newly developed clinical practices that are relatively common among Japanese experts in this field, although all of their statements are not associated with a high level of evidence, but these practices are likely to be incorporated into guidelines in the future. To write this article, coauthors from different institutions drafted the content and then critically reviewed each other’s work. The revised content was then critically reviewed by the Board of Directors and the Planning and Public Relations Committee of JSH before publication to confirm the consensus statements and recommendations. The consensus statements and recommendations presented in this report represent measures actually being conducted at the highest-level HCC treatment centers in Japan. We hope this article provides insight into the actual situation of HCC practice in Japan, thereby affecting the global practice pattern in the management of HCC

    Reexamination of Refrigeration Power of the LHD Cryogenic System After Fire and Restart of Operation

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    The Large Helical Device (LHD), built in the 1990s, is a heliotron-type fusion plasma experimental device with the world\u27s first fully superconducting magnetic confinement system. The LHD cryogenic system operated stably for 18 years from 1998 to 2015 with high availability exceeding 99%. Unfortunately, in August 2015, a fire occurred in the cold box of the He refrigerator during maintenance, and nonmetallic components such as multilayer insulation films, temperature sensors, and measuring instruments were burnt down. Repair work started in November 2015 and completed at the end of July 2016. In August 2016, a test operation of the He refrigerator was conducted, and the refrigeration power was compared with that measured in the initial performance test conducted in 1995. The measured equivalent refrigeration power at 4.4 K was 9.19 kW, representing a decrease ~2% from the value of 9.38 kW measured in 1995. We attributed this slight decrease in refrigeration power to performance deterioration owing to aging over 18 years and not to the fire. The LHD restarted operation in January 2017, and its 19th operational cycle for a deuterium plasma experiment was conducted successfully up to August 2017. This paper reports the operational history and restart of the LHD superconducting magnet and cryogenic system

    Neutrophil Depletion Exacerbates Pregnancy Complications, Including Placental Damage, Induced by Silica Nanoparticles in Mice

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    Recent advances in nanotechnology have led to the development of nanoparticles with innovative functions in various fields. However, the biological effects of nanoparticles—particularly those on the fetus—need to be investigated in detail, because several previous studies have shown that various nanoparticles induce pregnancy complications in mice. In this regard, our previous findings in mice suggested that the increase in peripheral neutrophil count induced by treatment with silica nanoparticles with a diameter of 70 nm (nSP70) may play a role in the associated pregnancy complications. Therefore, here, we sought to define the role of neutrophils in nSP70-induced pregnancy complications. The peripheral neutrophil count in pregnant BALB/c mice at 24 h after treatment with nSP70 was significantly higher than in saline-treated mice. In addition, maternal body weight, uterine weight, and the number of fetuses in nSP70-treated mice pretreated with anti-antibodies, which deplete neutrophils, were significantly lower than those in nSP70-treated mice pretreated with phosphate-buffered saline or isotype-matched control antibodies. Histology revealed that neutrophil depletion increased nSP70-induced placental damage from the decidua through the spongiotrophoblast layer and narrowed spiral arteries in the placentae. In addition, depletion of neutrophils augmented nSP70-induced cytotoxicity to fetal vessels, which were covered with endothelium. The rate of apoptotic cell death was significantly higher in the placentae of anti-nSP70-treated mice than in those from mice pretreated with isotype-matched control antibodies. Therefore, impairment of placental vessels and apoptotic cell death due to nSP70 exposure is exacerbated in the placentae of nSP70-treated mice pretreated with anti-antibodies. Depletion of neutrophils worsens nSP70-induced pregnancy complications in mice; this exacerbation was due to enhanced impairment of placental vessels and increased apoptotic cell death in maternal placentae. Our results provide basic information regarding the mechanism underlying silica-nanoparticle-induced pregnancy complications
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