201 research outputs found

    Probing Atomic Structure and Majorana Wavefunctions in Mono-Atomic Fe-chains on Superconducting Pb-Surface

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    Motivated by the striking promise of quantum computation, Majorana bound states (MBSs) in solid-state systems have attracted wide attention in recent years. In particular, the wavefunction localization of MBSs is a key feature and crucial for their future implementation as qubits. Here, we investigate the spatial and electronic characteristics of topological superconducting chains of iron atoms on the surface of Pb(110) by combining scanning tunneling microscopy (STM) and atomic force microscopy (AFM). We demonstrate that the Fe chains are mono-atomic, structured in a linear fashion, and exhibit zero-bias conductance peaks at their ends which we interprete as signature for a Majorana bound state. Spatially resolved conductance maps of the atomic chains reveal that the MBSs are well localized at the chain ends (below 25 nm), with two localization lengths as predicted by theory. Our observation lends strong support to use MBSs in Fe chains as qubits for quantum computing devices.Comment: 13 pages, 3 figure

    A New Minimally Invasive Technique of Combined Chest Wall Resection for Lung Cancer : Advanced Data of Implication of Advanced Bipolar Device in Video-Assisted Chest Wall Resection for Lung Cancer.

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    We describe a novel method for resecting lung cancer that has invaded the chest wall using an advanced bipolar device during video-assisted thoracoscopic surgery. The method is convenient for both tumor and chest wall resection because it is easy to handle and less invasive than the currently used technique

    Atomic-scale dissipation processes in dynamic force spectroscopy

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    A systematic distance-dependent measurement of the quasistatic tip-sample interactions reveals a hidden stochastic dissipative interaction of the atomic-scale contact in dynamic force microscopy. By comparison of experiment with detailed molecular dynamics simulations, we demonstrate that the infrequently observed hysteresis loops are attributed to the formation of atomic chains during tip retraction. These lead to a large magnitude of energy dissipation in a single cycle and dominate the average measured dissipation, while also leading to differences in the forces measured in static and dynamic force microscopy. This paper provides quantitative force measurements and insights into atomic-scale dissipation processes.Peer reviewe

    ガンマデルタT細胞を介したミノドロン酸の非小細胞肺癌細胞株に対するアポトーシス誘導効果の検討

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    Background/aim: Non-small cell lung carcinoma (NSCLC) is one of the leading causes of cancer-related death worldwide. Recent studies showed that nitrogen-containing bisphosphonates (N-BPs) directly and indirectly prevent proliferation, induce apoptosis, and inhibit metastasis of various types of cancer cell. In order to investigate the effect of combining minodronic acid (MDA) with γδ T-cells, NSCLC cells were treated with five concentrations of MDA. Materials and methods: NSCLC cells were cultured with different concentrations of MDA alone or in combination with γδ T-cells for 24 h. Results: MDA with γδ T-cells had differential apoptotic effects on the NSCLC cell lines. The cells showed significant apoptotic effects in the presence of MDA in a dose-dependent manner. Conclusion: This study is the first to report an indirect effect of MDA against NSCLC. We report the induction of apoptosis by MDA in combination with γδ T-cells.博士(医学)・乙第1446号・令和元年12月5日Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.発行元の規定により、本文の登録不可。本文は以下のURLを参照 "http://dx.doi.org/10.21873/anticanres.11174"(※全文閲覧は学内限定

    A Multi-scale Approach for Simulations of Kelvin Probe Force Microscopy with Atomic Resolution

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    The distance dependence and atomic-scale contrast observed in nominal contact potential difference (CPD) signals recorded by KPFM on surfaces of insulating and semiconducting samples, have stimulated theoretical attempts to explain such effects. We attack this problem in two steps. First, the electrostatics of the macroscopic tip-cantilever-sample system is treated by a finite-difference method on an adjustable nonuniform mesh. Then the resulting electric field under the tip apex is inserted into a series of atomistic wavelet-based density functional theory (DFT) calculations. Results are shown for a realistic neutral but reactive silicon nano-scale tip interacting with a NaCl(001) sample. Bias-dependent forces and resulting atomic displacements are computed to within an unprecedented accuracy. Theoretical expressions for amplitude modulation (AM) and frequency modulation (FM) KPFM signals and for the corresponding local contact potential differences (LCPD) are obtained by combining the macroscopic and atomistic contributions to the electrostatic force component generated at the voltage modulation frequency, and evaluated for several tip oscillation amplitudes A up to 10 nm. Being essentially constant over a few Volts, the slope of atomistic force versus bias is the basic quantity which determines variations of the atomic-scale LCPD contrast. Already above A = 0.1 nm, the LCPD contrasts in both modes exhibit almost the same spatial dependence as the slope. In the AM mode, this contrast is approximately proportional to A1/2A^{-1/2}, but remains much weaker than the contrast in the FM mode, which drops somewhat faster as A is increased. These trends are a consequence of the macroscopic contributions to the KPFM signal, which are stronger in the AM-mode and especially important if the sample is an insulator even at sub-nanometer separations where atomic-scale contrast appears.Comment: 19 pages, 13 figure

    Effectiveness of Cross‐Linked Gelatin Glue in Canine Lung Surgery Models.

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    Background. Air leakage is a common postoperative complication in pulmonary surgery, and surgical sealants have been developed to prevent or reduce the incidence of air leaks. In this study, we evaluated the efficacy of cross-linked gelatin glue (gelatin plus glutaraldehyde) in canine lung surgery models. Methods. Pulmonary fistulas and injuries were created in dogs and sealed with gelatin glue, fibrin glue, or fibrin glue with a polyglycolic acid (PGA) sheet. Seal-breaking pressures were measured in the fistula model, and pleural adhesions were assessed 28 days postoperatively in the lung injury model. Results. The seal-breaking pressures for canine cadaver and living lung surgeries (; the maximum pressures were 80 and 40 cm H₂O) were respectively: gelatin glue, 77 ± 6 and 32.3 ± 8.9cm H₂O; fibrin glue using spray, 39.2 ± 9.3 and 32 ± 6cm H₂O; fibrin glue using the rub-and-soak method, 35 ± 13.4 and 40 ± 0 cm H₂O; and fibrin glue with a PGA sheet, 55.5 ± 18.2 and 39 ± 2cm H₂O. In the lung injury model, there were no chest wall adhesions in the gelatin and fibrin glue alone groups, while strong adhesions were observed when treated with fibrin glue with a PGA sheet. Conclusions. Gelatin glue's sealing effect was superior to that of fibrin glue while preventing postoperative pleural adhesions. These findings suggest that gelatin glue may be effective as a surgical sealant or anti-adhesion materialin lung surgery

    Circulatory C-type natriuretic peptide reduces mucopolysaccharidosis-associated craniofacial hypoplasia in vivo

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    Skeletal alterations in the head and neck region, such as midfacial hypoplasia, foramen magnum stenosis and spinal canal stenosis, are commonly observed in patients with mucopolysaccharidosis (MPS). However, enzyme replacement therapy (ERT), one of the major treatment approaches for MPS, shows limited efficacy for skeletal conditions. In this study, we analysed the craniofacial morphology of mice with MPS type VII, and investigated the underlying mechanisms promoting jaw deformities in these animals. Furthermore, we investigated the effects of C-type natriuretic peptide (CNP), a potent endochondral ossification promoter, on growth impairment of the craniofacial region in MPS VII mice when administered alone or in combination with ERT. MPS VII mice exhibited midfacial hypoplasia caused by impaired endochondral ossification, and histological analysis revealed increased number of swelling cells in the resting zone of the spheno-occipital synchondrosis (SOS), an important growth centre for craniomaxillofacial skeletogenesis. We crossed MPS VII mice with transgenic mice in which CNP was expressed in the liver under the control of the human serum amyloid-P component promoter, resulting in elevated levels of circulatory CNP. The maxillofacial morphological abnormalities associated with MPS VII were ameliorated by CNP expression, and further prevented by a combination of CNP and ERT. Histological analysis showed that ERT decreased the swelling cell number, and CNP treatment increased the width of the proliferative and hypertrophic zones of the SOS. Furthermore, the foramen magnum and spinal stenoses observed in MPS VII mice were significantly alleviated by CNP and ERT combination. These results demonstrate the therapeutic potential of CNP, which can be used to enhance ERT outcome for MPS VII-associated head and neck abnormalities

    Local Probe Isomerization in a One-Dimensional Molecular Array

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    Synthesis of one-dimensional molecular arrays with tailored stereoisomers is challenging yet has a great potential for application in molecular opto-, electronic- and magnetic-devices, where the local array structure plays a decisive role in the functional properties. Here, we demonstrate construction and characterization of dehydroazulene isomer and diradical units in three-dimensional organometallic compounds on Ag(111) with a combination of low-temperature scanning tunneling microscopy and density functional theory calculations. Tip-induced voltage pulses firstly result in the formation of a diradical species via successive homolytic fission of two C-Br bonds in the naphthyl groups, which are subsequently transformed into chiral dehydroazulene moieties. The delicate balance of the reaction rates among the diradical and two stereoisomers, arising from an in-line configuration of tip and molecular unit, allows directional azulene-to-azulene and azulene-to-diradical local probe isomerization in a controlled manner. Furthermore, we found that the diradical moiety hosts an open-shell singlet with antiferromagnetic coupling between the unpaired electrons, which can undergo an inelastic spin transition of 91 meV to the ferromagnetically coupled triplet state

    Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer

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    The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy.Kawai M.Y., Ozasa R., Ishimoto T., et al. Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer. Materials, 15, 3, 993. https://doi.org/10.3390/ma15030993
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