532 research outputs found

    Effect of Neutron Irradiation on the Microstructures and Tensile Properties of Different Carbon Fibers

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    Since carbon fiber reinforced carbon composite (C/C composite) materials have high thermal conductivity and good mechanical properties, they have been used as the plasma facing components in fusion facilities. As the plasma facing components are subjected to neutron irradiation in the fusion reactors, it is necessary to use irradiation damage resistant C/C composite materials as plasma facing components. Properties of C/C composite materials after neutron irradiation are generally influenced by irradiation behavior of carbon fiber and carbon matrix. In particular, the effect of irradiation on carbon fiber is important, because it is less crystalline than carbon matrix. The purpose of this study is to evaluate neutron irradiation effects on the microstructures and tensile properties of nine kinds of carbon fibers and to find out the necessary knowledge to identify the radiation resistant carbon fiber

    Pollution of Polyaromatic Hydrocarbons in the Airborne Particles in the Developing Countries in Asia Region

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    Joint Research on Environmental Science and Technology for the Eart

    Possibility of multivariate function composed of plasma amino acid profiles as a novel screening index for non-small cell lung cancer: a case control study

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    <p>Abstract</p> <p>Background</p> <p>The amino-acid balance in cancer patients often differs from that in healthy individuals, because of metabolic changes. This study investigated the use of plasma amino-acid profiles as a novel marker for screening non-small-cell lung cancer (NSCLC) patients.</p> <p>Methods</p> <p>The amino-acid concentrations in venous blood samples from pre-treatment NSCLC patients (<it>n </it>= 141), and age-matched, gender-matched, and smoking status-matched controls (<it>n </it>= 423), were measured using liquid chromatography and mass spectrometry. The resultant study data set was subjected to multiple logistic regression analysis to identify amino acids related with NSCLC and construct the criteria for discriminating NSCLC patients from controls. A test data set derived from 162 patients and 3,917 controls was used to validate the stability of the constructed criteria.</p> <p>Results</p> <p>The plasma amino-acid profiles significantly differed between the NSCLC patients and the controls. The obtained model (including alanine, valine, isoleucine, histidine, tryptophan and ornithine concentrations) performed well, with an area under the curve of the receiver-operator characteristic curve (ROC_AUC) of >0.8, and allowed NSCLC patients and controls to be discriminated regardless of disease stage or histological type.</p> <p>Conclusions</p> <p>This study shows that plasma amino acid profiling will be a potential screening tool for NSCLC.</p

    Single-cell dynamics of pannexin-1-facilitated programmed ATP loss during apoptosis

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    死にゆく細胞のATP濃度変化を詳細に可視化することに成功 --積極的にATP濃度を下げる因子を明らかに--. 京都大学プレスリリース. 2020-10-22.ATP is essential for all living cells. However, how dead cells lose ATP has not been well investigated. In this study, we developed new FRET biosensors for dual imaging of intracellular ATP level and caspase-3 activity in single apoptotic cultured human cells. We show that the cytosolic ATP level starts to decrease immediately after the activation of caspase-3, and this process is completed typically within 2 hr. The ATP decrease was facilitated by caspase-dependent cleavage of the plasma membrane channel pannexin-1, indicating that the intracellular decrease of the apoptotic cell is a ‘programmed’ process. Apoptotic cells deficient of pannexin-1 sustained the ability to produce ATP through glycolysis and to consume ATP, and did not stop wasting glucose much longer period than normal apoptotic cells. Thus, the pannexin-1 plays a role in arresting the metabolic activity of dead apoptotic cells, most likely through facilitating the loss of intracellular ATP

    Early Spectroscopy of the 2010 Outburst of U Scorpii

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    We present early spectroscopy of the recurrent nova U~Sco during the outburst in 2010. We successfully obtained time-series spectra at td=t_{\rm d}=0.37--0.44~d, where tdt_{\rm d} denotes the time from the discovery of the present outburst. This is the first time-resolved spectroscopy on the first night of U Sco outbursts. At td0.4t_{\rm d}\sim 0.4~d the Hα\alpha line consists of a blue-shifted (5000-5000 km s1^{-1}) narrow absorption component and a wide emission component having triple peaks, a blue (3000\sim -3000 km s1^{-1}), a central (0\sim 0 km s1^{-1}) and a red (+3000\sim +3000 km s1^{-1}) ones. The blue and red peaks developed more rapidly than the central one during the first night. This rapid variation would be caused by the growth of aspherical wind produced during the earliest stage of the outburst. At td=1.4t_{\rm d}=1.4~d the Hα\alpha line has a nearly flat-topped profile with weak blue and red peaks at ±3000\sim \pm 3000 km s1^{-1}. This profile can be attributed to a nearly spherical shell, while the asphericity growing on the first night still remains. The wind asphericity is less significant after td=9t_{\rm d}=9 d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter
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