218 research outputs found

    Site-dependent Local Spin Susceptibility and Low-energy Excitation in a Weyl Semimetal WTe2_2

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    Site-dependent local spin susceptibility is investigated with 125^{125}Te nuclear magnetic resonance in a Weyl semimetal WTe2_2. The nuclear spin-lattice relaxation rate 1/T1T1/T_1T shows a dependence of the square of temperature TT at high temperatures, followed by a constant behavior below 50 K. The temperature dependence features Weyl fermions appearing around the linearly crossing bands. The Knight shift KK scales to the square root of 1/T1T1/T_1T, corroborating a predominant spin contribution in low-lying excitation. The observed dependence of KK and 1/T1T1/T_1T on the four Te sites shows the site-dependent electron correlation and density of states. The angular profile of the NMR spectrum gives the anisotropic hyperfine coupling tensor, consistent with 5p5p hole occupations on Te sites.Comment: 6 pages, 5 figure

    The preparation of an infectious full-length cDNA clone of Saffold virus

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    The pathogenicity of Saffold virus (SAFV) among humans still remains unclear, although it was identified as a novel human cardiovirus in 2007. In order to encourage the molecular pathogenetic studies of SAFV, we generated an infectious cDNA clone of SAFV type 3 (SAFV-3). The present study demonstrated that the synthesis of the full-length infectious RNA by T7 RNA polymerase was terminated by a homologous sequence motif with the human preproparathyroid hormone (PTH) signal in the SAFV-3 genome. To obtain the infectious RNA using T7 promoter, a variant of T7 RNA polymerase, which fails to recognize the PTH signal, was useful. This study will provide a valuable technical insight into the reverse genetics of SAFV

    Synthesis of carbon nanotubes by microwave heating: Influence of diameter of catalytic Ni nanoparticles on diameter of CNTs

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    We rapidly synthesized multi walled carbon nanotubes (MWCNTs) by calcination of granulated polystyrene with nickel nanoparticles having different average diameter (D-Ni = 10, 20, 50 or 90 nm) under nitrogen gas at a certain temperature and time (700 degrees C, 15 min or 800 degrees C, 10 min), using a domestic microwave oven in order to systematically investigate the influence of the diameter of nickel nanoparticles on the diameter of MWCNTs. The MWCNTs synthesized here were characterized by a transmission electron microscope, a Raman spectrophotometer and a wide angle X-ray diffractometer. We found that for the calcination condition of (800 degrees C, 10 min), a relationship between the outer diameter of the resulted carbon nanotubes (D-CNT) and the diameter of catalytic nickel nanoparticles (D-Ni) can be described as a linear function, D-CNT = 1.01D(Ni) + 14.79 nm with the correlation coefficient R = 0.99, and that for the calcination condition of 700 degrees C, 15 min, D-CNT = 1.12D(Ni) + 7.80 nm with R = 0.95. Thus, we revealed that when the diameter of the catalytic nickel nanoparticles (D-Ni) increases by 1 nm, the outer diameter of the obtained MWCNTs (D-CNT) increases by about 1 nm.ArticleJOURNAL OF MATERIALS CHEMISTRY A. 2(8):2773-2780 (2014)journal articl

    De novo NSF mutations cause early infantile epileptic encephalopathy

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    Nā€ethylmaleimideā€sensitive factor (NSF) plays a critical role in intracellular vesicle transport, which is essential for neurotransmitter release. Herein, we, for the first time, document human monogenic disease phenotype of de novo pathogenic variants in NSF, that is, epileptic encephalopathy of early infantile onset. When expressed in the developing eye of Drosophila, the mutant NSF severely affected eye development, while the wildā€type allele had no detectable effect under the same conditions. Our findings suggest that the two pathogenic variants exert a dominant negative effect. De novo heterozygous mutations in the NSF gene cause early infantile epileptic encephalopathy

    Atomically precise incorporation of BN doped rubicene into graphene nanoribbons

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    Substituting heteroatoms and non-benzenoid carbons into nanographene structure offers an unique opportunity for atomic engineering of electronic properties. Here we show the bottom-up synthesis of graphene nanoribbons (GNRs) with embedded fused BN-doped rubicene components on a Au(111) surface using on-surface chemistry. Structural and electronic properties of the BN-GNRs are characterized by scanning tunneling microscopy (STM) and atomic force microscopy (AFM) with CO-terminated tips supported by numerical calculations. The periodic incorporation of BN heteroatoms in the GNR leads to an increase of the electronic band gap as compared to its undoped counterpart. This opens avenues for the rational design of semiconducting GNRs with optoelectronic properties.Comment: 18 pages, 4 figure

    Effect of Cation Structure of Ionic Liquids on Anode Properties of Si Electrodes for LIB

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    Ionic liquids consisted of 1-((2-methoxyethoxy)methyl)-1-methylpiperidinium (PP1MEM) or 1-hexyl-1-methylpiperidinium (PP16) and bis(trifluoromethanesulfonyl)amide (TFSA) were applied to an electrolyte for Li-ion battery. The effect of their cation structure on anode properties of Si electrodes were investigated through the use of thick film prepared by gas-deposition without any binder and conductive additive. The Si electrode in PP1MEM-TFSA exhibited an initial reversible capacity of 2670 mA h gāˆ’1, which is larger than that in PP16-TFSA by ca. 900 mA h gāˆ’1. Moreover, a comparatively high capacity of 1150 mA h gāˆ’1 at a high current density of 4200 mA gāˆ’1 is achieved in PP1MEM-TFSA whereas the Si electrode in PP16-TFSA showed the capacity of only 210 mA h gāˆ’1. Raman analysis and electrochemical impedance measurements revealed that PP1MEM cation played a role reducing the interaction between Li ion and TFSA anions, and that Li-ion transfer at the electrodeāˆ’electrolyte interface in PP1MEM-TFSA was remarkably improved compared with PP16-TFSA. These results indicate that the excellent performances obtained in PP1MEM-TFSA originate from a smooth Li-insertion into Si electrode. It was suggested that introduction of ether functional group into cation is valid to enhance the electrode performance

    Antiplatelet antibody may cause delayed transfusion-related acute lung injury

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    A 61-year-old woman with lung cancer developed delayed transfusion-related acute lung injury (TRALI) syndrome after transfusion of plasma- and leukoreduced red blood cells (RBCs) for gastrointestinal bleeding due to intestinal metastasis. Acute lung injury (ALI) recurred 31 days after the first ALI episode. Both ALI episodes occurred 48 hours after transfusion. Laboratory examinations revealed the presence of various antileukocyte antibodies including antiplatelet antibody in the recipientā€™s serum but not in the donorsā€™ serum. The authors speculate that antiplatelet antibodies can have an inhibitory effect in the recipient, which can modulate the bona fide procedure of ALI and lead to a delay in the onset of ALI. This case illustrates the crucial role of a recipientā€™s platelets in the development of TRALI

    Electrochemical Na-Insertion/Extraction Properties of Phosphorus Electrodes in Ionic Liquid Electrolytes

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    The electrochemical Na-insertion/extraction properties of phosphorus as a Na-ion battery anode in ionic liquid electrolytes were investigated by using a thick film without any binder or conductive additive. The ionic liquid with more electrochemically-stable cation structure, 1-((2-methoxyethoxy)methyl)-1-methylpyrrolidinium bis(fluorosulfonyl)amide (Py1MEM-FSA), delivered a high reversible capacity of 310 mA h gāˆ’1 at the 100th cycle, whereas the phosphorus electrode in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)amide (EMI-FSA) showed a low capacity of only 110 mA h gāˆ’1. It was revealed that disintegration of the electrode after cycling was effectively suppressed by applying Py1MEM-FSA instead of an organic electrolyte including propylene carbonate (PC), and that a surface layer induced by the decomposition of EMI-FSA hindered Na-insertion into the active material layer. The performance obtained in Py1MEM-FSA was very superior to that in PC. We applied for the first time a closed-system fire-resistance test to the ionic liquid electrolyte for quantitatively evaluating its non-flammability. The Py1MEM-FSA-based electrolyte exhibited an excellent fire resistance in comparison with the PC-based organic electrolyte, which can be an advantage for realizing a Na-ion battery with a high-energy density and a high safety

    Influence of the structure of the anion in an ionic liquid electrolyte on the electrochemical performance of a silicon negative electrode for a lithium-ion battery

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    We investigated the influence of the anions in ionic liquid electrolytes on the electrochemical performance of a silicon (Si) negative electrode for a lithium-ion battery. While the electrode exhibited poor cycle stability in tetrafluoroborate-based and propylene carbonate-based electrolytes, better cycle performance was achieved in bis(fluorosulfonyl)amide (FSAā€“)- and bis(trifluoromethanesulfonyl)amide (TFSAā€“)-based electrolytes, in which the discharge capacity of a Si electrode was more than 1000 mA h gā€“1 at the 100th cycle. It is considered that a surface film derived from FSAā€“- and TFSAā€“-based electrolytes effectively suppressed continuous decomposition of the electrolyte. In a capacity limitation test, a discharge capacity of 1000 mA h gā€“1 was maintained even after about the 1600th cycle in the FSAā€“-based electrolyte, which corresponds to a cycle life almost twice as long as that in TFSAā€“-based electrolyte. This result should be explained by the high structural stability of FSAā€“-derived surface film. In addition, better rate capability with a discharge capacity of 700 mA h gā€“1 was obtained at a high current rate of 6 C (21 A gā€“1) in FSAā€“-based electrolyte, which was 7-fold higher than that in TFSAā€“-based electrolyte. These results clarified that FSAā€“-based ionic liquid electrolyte is the most promising candidate for Si-based negative electrodes
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