82 research outputs found

    Global modelling of tungsten impurity transport based on the drift-kinetic equation, Nuclear Fusion

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    A global kinetic simulation model of collisional impurity transport is developed for evaluating the radial particle flux of tungsten impurity in the edge region of a tokamak plasma. Here, the plasma including the impurity and the background ion is presupposed to be quasi-steady. The simulation model is based on the drift-kinetic equation of the impurity affected by the friction force and the thermal force, which were formulated in the previous study (Homma et al 2016 Nucl. Fusion 56 036009). The model is implemented in a drift-kinetic simulation code. We find that the magnetic drift term in the drift-kinetic equation causes the \u27global effect\u27 on the impurity transport. Here, the global effect means that the solution of the drift-kinetic equation (and also the radial particle flux) on a magnetic flux surface is influenced by the values of the solution all over the edge region

    The development of a zero-dimensional collisional-radiative model for interpreting plasma emission in low temperature divertor plasmas in tokamaks

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    Collisional-radiative models are commonly used to analyse atomic and molecular processes in low temperature plasmas by determining the distribution functions of excited states as functions of various plasma parameters. This paper outlines the improvements to a zero-dimensional collisional-radiative model, developed at Keio University, for purposes relevant to the analysis of emission measurements in low temperature hydrogen plasmas. The extension of this 0D model centres on the inclusion of additional molecular species and reactions, a calculation of emission intensity in order to directly compare with experimental work, and the addition of a simple wall model to allow for a deeper understanding of recycling of atoms and molecules in low temperature plasmas close to plasma facing components in fusion machines. Results from the improved model are then compared with both an existing CR model for benchmarking and experimental emission spectroscopy data from an inductively-coupled plasma device at the University of Liverpool. These results show how the developments to the model have increased the relevance to experimental plasmas, such as those in the power exhaust regions of fusion machines, with the ratio of the Hβ/Hα line intensities outputted from the improved CR model mirroring more closely the emission measured experimentally in the ICP device

    Impact of postoperative complications after primary tumor resection on survival in patients with incurable stage IV colorectal cancer: A multicenter retrospective cohort study

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    [Aims] Primary tumor resection for patients with incurable stage IV colorectal cancer can prevent tumor-related complications but may cause postoperative complications. Postoperative complications delay the administration of chemotherapy and can lead to the spread of malignancy. However, the impact of postoperative complications after primary tumor resection on survival in patients with incurable stage IV colorectal cancer remains unclear. Therefore, this study aimed to investigate how postoperative complications after primary tumor resection affect survival in this patient group. [Methods] We reviewed data on 966 patients with stage IV colorectal cancer who underwent palliative primary tumor resection between January 2006 and December 2007. We examined the association between major complications (National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 grade 3 or more) and overall survival using Cox proportional hazard model and explored risk factors associated with major complications using multivariable logistic regression analysis. [Results] Ninety-three patients (9.6%) had major complications. The 2-year overall survival rate was 32.7% in the group with major complications and 50.3% in the group with no major complications. Patients with major complications had a significantly poorer prognosis than those without major complications (hazard ratio: 1.62; 95% confidence interval: 1.21-2.18; P < .01). Male, rectal tumor, and open surgery were identified to be risk factors for major complications. [Conclusions] Postoperative complications after primary tumor resection was associated with decreased long-term survival in patients with incurable stage IV colorectal cancer

    Detection of Thyroid Carcinoma Antigen with Quantum Dots and Monoclonal IgM Antibody (JT-95) System

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    High-intensity fluorescent nanoparticles, quantum dots (QDs), have been applied to a wide range of biological studies and medical studies by taking advantage of their fluorescent properties. On the other hand, we have reported the specificity of JT-95 monoclonal IgM antibody, which recognizes the antigen of thyroid carcinomas. Here we show that the combination of QDs and JT-95 monoclonal antibody was applicable to Western blotting analysis, ELISA-like system, and fluorescent microscopic analysis of SW1736 thyroid carcinoma cell line. We have opened up the possibility that antibodies for higher specific recognition, even IgM, are applicable to the detection system with QDs

    Calcitonin Receptor Signaling Inhibits Muscle Stem Cells from Escaping the Quiescent State and the Niche

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    Masahiko Yamaguchi, Yoko Watanabe, Takuji Ohtani, Akiyoshi Uezumi, Norihisa Mikami, Miki Nakamura, Takahiko Sato, Masahito Ikawa, Mikio Hoshino, Kunihiro Tsuchida, Yuko Miyagoe-Suzuki, Kazutake Tsujikawa, Shin’ichi Takeda, Hiroshi Yamamoto, So-ichiro Fukada, Calcitonin Receptor Signaling Inhibits Muscle Stem Cells from Escaping the Quiescent State and the Niche, Cell Reports, Volume 13, Issue 2, 2015, Pages 302-314, ISSN 2211-1247, https://doi.org/10.1016/j.celrep.2015.08.083

    Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System

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    Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1) system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source) and keto acids (oxylic acid sources). In this research, several amino acids were detected with an amino acid analyzer. Moreover, alanine polymers were detected with LC-MS. Our research lights up a new pathway in the study of life’s origin

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    2016 Comprehensive Update of the Banff Working Group on Liver Allograft Pathology: Introduction of Antibody-Mediated Rejection

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    The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody-mediated liver allograft rejection at the 11th (Paris, France, June 5-10, 2011), 12th (Comandatuba, Brazil, August 19-23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5-10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody-mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included

    Pressure Field Visualisation on the Surface of a Square Cylinder with Pressure Sensitive Paints

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    Pressure Sensitive Paints (PSP) are one of the breakthrough technologies for the measurement of aerodynamic sound from automobiles. Potential problems in applying Pressure Sensitive Paints to automobiles are low time resolution and less accuracy in the low-speed flow field. In this investigation, we attempted to improve the accuracy of PSP in a low-speed flow. A suction-type wind tunnel, which has a square test section of 75 mm by 150 mm, was developed to remove the influence of temperature differences during the wind tunnel experiments. A carefully selected array of ultraviolet LEDs was utilised as a lighting system to match the effective excitation wavelength of the developed PSP (390 nm). The surface pressure of a square cylinder was measured at velocities ranging from 35 m/s to 75 m/s with PSP and a conventional pressure sensor. The experimental data were compared with the results of conventional pressure measurements and numerical simulations. The experimental results showed that the accuracy of the PSP was about 10% at the velocities of 65 m/s or higher. The pressure profiles can be clearly observed at the uniform velocity of 75 m/s. Conversely, accuracy within the 35 m/s to 55 m/s velocity range was not high enough because of insufficient CCD camera resolution. Despite large error values, the colour depths of the luminescence images were almost identical for the same experimental conditions. This indicated that the calibration coefficients of the Stern-Volmer relation were almost constant during the experiments. It revealed that the suction-type wind tunnel is suitable for PSP measurements
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