87 research outputs found

    Low-Temperature Characteristics of an AlN/Diamond Surface Acoustic Wave Resonator

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    Phonons confined in mechanical resonators can be coupled to a variety of quantum systems and are expected to be applied to hybrid quantum systems. Diamond surface acoustic wave (SAW) devices are capable of high efficiency in phonon interaction with color centers in diamond. The temperature dependence of the quality factor is crucial for inferring the governing mechanism of coupling efficiency between phonons and color centers in diamond. In this paper, we report on the temperature dependence of the quality factor of an AlN/diamond SAW device from room temperature to 5 K. The temperature dependence of the quality factor and resonant frequency suggests that the mechanism of SAW dissipation in the AlN/diamond SAW resonator at 5 GHz is the phonon-phonon scattering in the Akheiser region, and that further cooling can be expected to improve the quality factor. This result provides a crucial guideline for the future design of AlN/diamond SAW devices.Comment: 10 pages, 5 figure

    Bilateral verses bilateral with tri-segmental endoscopic drainage using metal stents for high-grade malignant hilar biliary obstructions: A multicenter, randomized controlled trial: BRAVE study (BRAVE study)

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    Introduction: Bilateral endoscopic drainage with self-expanding metallic stent (SEMS) can be used to manage hilar malignant biliary obstruction (HMBO) more effectively in comparison to unilateral drainage. An increased drainage area is predicted to prolong stent patency and patient survival. However, few reports have described the utility of trisegmental drainage and the benefits of using trisegmental drainage remain unknown. Thus, we launched a randomized clinical trial (RCT) to compare the clinical outcomes between bilateral and trisegmental drainage using SEMSs in patients with high-grade HMBO. Methods and analysis: This study was conducted as a multicenter randomized control trial (RCT) in 8 high-volume medical centers in Japan, and will prove the non-inferiority of bilateral drainage to trisegmental drainage. Patients with unresectable HMBO with Bismuth type IIIa or IV who pass the inclusion and exclusion criteria will be randomized to receive bilateral or trisegmental drainage at a 1:1 ratio. At each center, the on-site study investigators will obtain informed consent from the candidates, and will use an electronic data capture system (REDCap) to input necessary information, and register candidates with the registration secretariat. The primary endpoint is the rate of non-recurrent biliary obstruction (RBO) at 180 days after SEMSs placement. A -10% non-inferiority margin is assumed in the statistical analysis of the primary endpoint. Secondary endpoints include the rate of technical and clinical success, time to recurrent biliary obstruction (TRBO), causes of RBO, procedure-related adverse events (AEs), procedure time, TRBO with or without endoscopic sphincterotomy, overall survival, and the technical and clinical success rates at reintervention. Discussion: If the non-inferiority of bilateral drainage is demonstrated, it is predicted that the procedure time will be shortened and the medical cost will be reduced, which will be beneficial to the patient and the medical economy

    Impact of transport pathways on the time from symptom onset of ST-segment elevation myocardial infarction to door of coronary intervention facility

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    AbstractBackgroundReducing total ischemic time is important in achieving better outcome in ST-segment elevation myocardial infarction (STEMI). Although the onset-to-door (OTD) time accounts for a large portion of the total ischemic time, factors affecting prolongation of the OTD time are not established.PurposeThe purpose of this study was to determine the impact of transport pathways on OTD time in patients with STEMI.Methods and subjectsWe retrospectively studied 416 STEMI patients who were divided into 4 groups according to their transport pathways; Group 1 (n=41): self-transportation to percutaneous coronary intervention (PCI) facility; Group 2 (n=215): emergency medical service (EMS) transportation to PCI facility; Group 3 (n=103): self-transportation to non-PCI facility; and Group 4 (n=57): EMS transportation to non-PCI facility. OTD time was compared among the 4 groups.Essential resultsMedian OTD time for all groups combined was 113 (63–228.8)min [Group 1, 145 (70–256.5); Group 2, 71 (49–108); Group 3, 260 (142–433); and Group 4, 184 (130–256)min]. OTD time for EMS users (Groups 2 and 4) was 138min shorter than non-EMS users (Groups 1 and 3). Inter-hospital transportation (Groups 3 and 4) prolonged OTD by a median of 132min compared with direct transportation to PCI facility (Groups 1 and 2). Older age, history of myocardial infarction, prior PCI, shock at onset, high Killip classification, and high GRACE Risk Score were significantly more frequent in EMS users.Principal conclusionsSelf-transportation without EMS and inter-hospital transportation were significant factors causing prolongation of the OTD time. Approximately 35% of STEMI patients did not use EMS and 21% of patients were transported to non-PCI facilities even though they called EMS. Awareness in the community as well as among medical professionals to reduce total ischemic time of STEMI is necessary; this involves educating the general public and EMS crews

    A Fusion-Spliced Near-Field Optical Fiber Probe Using Photonic Crystal Fiber for Nanoscale Thermometry Based on Fluorescence-Lifetime Measurement of Quantum Dots

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    We have developed a novel nanoscale temperature-measurement method using fluorescence in the near-field called Fluorescence Near-field Optics Thermal Nanoscopy (Fluor-NOTN). Fluor-NOTN enables the temperature distributions of nanoscale materials to be measured in vivo/in situ. The proposed method measures temperature by detecting the temperature dependent fluorescence lifetimes of Cd/Se Quantum Dots (QDs). For a high-sensitivity temperature measurement, the auto-fluorescence generated from a fiber probe should be reduced. In order to decrease the noise, we have fabricated a novel near-field optical-fiber probe by fusion-splicing a photonic crystal fiber (PCF) and a conventional single-mode fiber (SMF). The validity of the novel fiber probe was assessed experimentally by evaluating the auto-fluorescence spectra of the PCF. Due to the decrease of auto-fluorescence, a six- to ten-fold increase of S/N in the near-field fluorescence lifetime detection was achieved with the newly fabricated fusion-spliced near-field optical fiber probe. Additionally, the near-field fluorescence lifetime of the quantum dots was successfully measured by the fabricated fusion-spliced near-field optical fiber probe at room temperature, and was estimated to be 10.0 ns

    GJETC report 2020 : German-Japanese cooperation in energy research ; supporting the closure of implementation gaps ; key results and policy recommendations

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    The German-Japanese Energy Transition Council (GJETC) was established in 2016 by experts from research institutions, energy policy think tanks, and practitioners in Germany and Japan. The objectives and main activities of the Council and the supporting secretariats are to identify and analyze current and future issues regarding policy frameworks, markets, infrastructure, and technological developments in the energy transition, and to hold Council meetings to exchange ideas and propose better policies and strategies. In its second project phase (2018-2020), the GJETC had six members from academia on the Japanese side, and eight members on the German side, with one Co-Chair from each country. From October 2018 to March 2020, the GJETC worked on and debated six topics: 1) Digitalization and the energy transition. 2) Hydrogen society. 3) Review of German and Japanese long-term energy scenarios and their evaluation mechanism. 4) Buildings, energy efficiency, heating/cooling. 5) Integration costs of renewable energies. 6) Transport and sector coupling. The outputs and the recommendations of the second phase of the GJETC are summarized in this report

    GJETC report 2018 : intensified German-Japanese cooperation in energy research ; key results and policy recommendations

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    The challenges and also potentials of the energy transition are tremendous in Germany, as well as in Japan. Sometimes, structures of the old energy world need "creative destruction" to clear the way for innovations for a decarbonized, low-risk energy system. In these times of disruptive changes, a constructive and sometimes controversial dialog within leading industrial nation as Japan and Germany over the energy transition is even more important. The German-Japanese Energy Transition Council (GJETC) released a summarizing report for the first project phase 2016-2018. It includes jointly formulated recommendations for politics as well as a controversial dialogue part. The Council jointly states and recommends that: Ambitious long-term targets and strategies for a low-carbon energy system must be defined and ambitiously implemented; Germany and Japan as high technology countries need to take the leadership. Both countries will have to restructure their energy systems substantially until 2050 while maintaining their competitiveness and securing energy supply. Highest priority is given to the forced implementation of efficiency technologies and renewable energies, despite different views on nuclear energy. In both countries all relevant stakeholders - but above all the decision-makers on all levels of energy policy - need to increase their efforts for a successful implementation of the energy transition. Design of the electricity market needs more incentives for flexibility options and for the extensive expansion of variable power generation, alongside with strategies for cost reduction for electricity from photovoltaic and wind energy. The implementation gap of the energy efficiency needs to be closed by an innovative energy policy package to promote the principle of "Energy Efficiency First". Synergies and co-benefits of an enhanced energy and resource efficiency policy need to be realized. Co-existence of central infrastructure and the growing diversity of the activities for decentralization (citizens funding, energy cooperatives, establishment of public utility companies) should be supported. Scientific cooperation can be intensified by a joint working group for scenarios and by the establishment of an academic exchange program

    A pentatricopeptide repeat protein acts as a site-specificity factor at multiple RNA editing sites with unrelated cis-acting elements in plastids

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    In plant organelles, RNA editing alters specific cytidine residues to uridine in transcripts. All of the site-specificity factors of RNA editing identified so far are pentatricopeptide repeat (PPR) proteins. A defect in a specific PPR protein often impairs RNA editing at multiple sites, at which the cis-acting elements are not highly conserved. The molecular mechanism for sharing a single PPR protein over multiple sites is still unclear. We focused here on the PPR proteins OTP82 and CRR22, the putative target elements of which are, respectively, partially and barely conserved. Recombinant OTP82 specifically bound to the −15 to 0 regions of its target sites. Recombinant CRR22 specifically bound to the −20 to 0 regions of the ndhB-7 and ndhD-5 sites and to the −17 to 0 region of the rpoB-3 site. Taking this information together with the genetic data, we conclude that OTP82 and CRR22 act as site-specificity factors at multiple sites in plastids. In addition, the high-affinity binding of CRR22 to unrelated cis-acting elements suggests that only certain specific nucleotides in a cis-acting element are sufficient for high-affinity binding of a PPR protein. The cis-acting elements can therefore be rather divergent and still be recognized by a single PPR protein

    Evaluation of optimal medical therapy in acute myocardial infarction patients with prior stroke

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    Background: Treatment of acute myocardial infarction (AMI) patients with prior stroke is a common clinical dilemma. Currently, the application of optimal medical therapy (OMT) and its impact on clinical outcomes are not clear in this patient population. Methods: We retrieved 765 AMI patients with prior stroke who underwent percutaneous coronary intervention (PCI) during the index hospitalization from the international multicenter BleeMACS registry. All of the subjects were divided into two groups based on the prescription they were given prior to discharge. Baseline characteristics and procedural variables were compared between the OMT and non-OMT groups. Mortality, re-AMI, major adverse cardiovascular events (MACE), and bleeding were followed-up for 1 year. Results: Approximately 5% of all patients presenting with AMI were admitted to the hospital for ischemic stroke. Although the prescription rate of each OMT medication was reasonably high (73.3%-97.3%), 47.7% lacked at least one OMT medication. Patients receiving OMT showed a significantly decreased occurrence of mortality (4.5% vs 15.1%, p < 0.001), re-AMI (4.2% vs 9.3%, p = 0.004), and the composite endpoint of death/re-AMI (8.6% vs 20.5%, p < 0.001) compared to those without OMT. No significant difference was observed between the groups regarding bleeding. After adjusting for confounding factors, OMT was the independent protective factor of 1-year mortality, while age was the independent risk factors. Conclusions: OMT at discharge was associated with a significantly lower 1-year mortality of patients with AMI and prior stroke in clinical practice. However, OMT was provided to just half of the eligible patients, leaving room for substantial improvement
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