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Michon B, Berthod C, Rischau CW, Ataei A, Chen L, Komiya S, Ono S, Taillefer L, van der Marel D, Georges A. Reconciling scaling of the optical conductivity of cuprate superconductors with Planckian resistivity and specific heat. Nat Commun 2023; 14:3033. [PMID: 37236962 DOI: 10.1038/s41467-023-38762-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Materials tuned to a quantum critical point display universal scaling properties as a function of temperature T and frequency ω. A long-standing puzzle regarding cuprate superconductors has been the observed power-law dependence of optical conductivity with an exponent smaller than one, in contrast to T-linear dependence of the resistivity and ω-linear dependence of the optical scattering rate. Here, we present and analyze resistivity and optical conductivity of La2-xSrxCuO4 with x = 0.24. We demonstrate ℏω/kBT scaling of the optical data over a wide range of frequency and temperature, T-linear resistivity, and optical effective mass proportional to [Formula: see text] corroborating previous specific heat experiments. We show that a T, ω-linear scaling Ansatz for the inelastic scattering rate leads to a unified theoretical description of the experimental data, including the power-law of the optical conductivity. This theoretical framework provides new opportunities for describing the unique properties of quantum critical matter.
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Iwami N, Komiya S, Asada Y, Tatsumi K, Habara T, Kuramoto T, Seki M, Yoshida H, Takeuchi K, Shiotani M, Mukaida T, Odawara Y, Mio Y, Kamiya H. P-384 Efficacy of endometrial microbiome metagenomic analysis with recurrent implantation failure and recurrent pregnancy loss: multicenter study in Japan. Hum Reprod 2022. [DOI: 10.1093/humrep/deac105.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Study question
Does the result of endometrial microbiome metagenomic analysis (EMMA), a next generation sequencing (NGS)-based test of the intrauterine microbiome, have an impact on pregnancy rate after the test?
Summary answer
After recommend treatment with antimicrobial and probiotic therapy, the group diagnosed as dysbiosis by EMMA achieved pregnancy significantly earlier than the group with Normal result.
What is known already
Using NGS technology, EMMA testing can determine the composition of the endometrial microbiome by analysing bacterial 16S ribosomal RNA with a focus on the lactobacillus population. Endometrial flora in patients undergoing in vitro fertilization (IVF) is often composed of pathogenic microorganisms which decrease implantation rates, such as the Enterobacteriaceae family, Staphylococcus spp., Escherichia coli and Gram-negative bacteria. Other studies also indicate that Lactobacillus spp. is a major microorganism in the endometrium. Especially, lactobacillus-dominated microbiota (LDM, defined as > 90% Lactobacillus spp.) in the endometrium has been reported to lead to better pregnancy outcomes than non-LDM (<90% Lactobacillus spp.).
Study design, size, duration
This study was a prospective, multicenter cohort study of 527 patients (under 42 years old) with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) at 14 IVF treatment facilities in Japan from June 2019 to August 2021. Defining RIF as three or more failed implantation attempts and RPL as two or more miscarriages, we examined the prognosis of two additional embryo transfers (ETs) after the EMMA test in patients who underwent the test.
Participants/materials, setting, methods
Endometrial tissue was obtained by aspiration from patients in day 15-25 of their menstrual cycles, and sample tissues were analyzed by NGS for EMMA. Participant centers treated patients according to the therapies specified in the reports, including antibiotic treatments, probiotic treatments, re-analysis, and embryo transfer. Multivariate analysis was performed using a generalized linear model with the endpoint of ongoing pregnancy. For the time-to-event analyses, we used Kaplan-Meier survival analysis to compare time to ongoing pregnancy.
Main results and the role of chance
The results of the first EMMA were as follows: 229 patients (43.4%) were normal with Lactobacillus spp. >90% (Normal group), 110 patients (20.9%) were abnormal with less than 90% Lactobacillus spp. and predominantly pathogenic bacteria (Abnormal group), and 188 patients (35.7%) were mild with low absolute amounts of bacteria and ultralow biomass indicating almost sterile (Mild + Ultralow group). There were no significant differences in background factors such as age, duration of infertility, number of previous ETs, or history of deliveries among the three groups. Gardnerella was the most pathogenic bacteria detected in patients with Abnormal EMMA results. All patients in the Abnormal group were treated with antimicrobials and probiotics, and those in Mild + Ultralow group were treated with probiotics. Odds ratio for ongoing pregnancy rate was 1.10(95%CI 0.67-1.82, p = 0.699) in Abnormal group and 1.23(95%CI 0.80-1.89, p = 0.342) in Mild + Ultralow group, respectively. After the intervention, ongoing pregnancies were comparable to those in Normal group.Analysis of time to pregnancy using Kaplan-Meier survival curves showed that Abnormal group had a significantly higher rate of ongoing pregnancies during the observation period than the other groups (p = 0.031).
Limitations, reasons for caution
Since this study was not necessarily limited to euploid embryos transferred after testing, an aging bias cannot be excluded. Since this study was conducted with all patients receiving EMMA, the effectiveness of the test needs to be further validated by comparison to patients without EMMA testing.
Wider implications of the findings
This study is the first multicenter study to demonstrate that the intervention based on EMMA reports improve pregnancy outcome in the patients with RIF and RPL. We suggest that the EMMA procedure, which aims at establishing an appropriate uterine microbiome, may be important for implantation and pregnancy continuation.
Trial registration number
UMIN000036917
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Ishidou Y, Hirotsu M, Setoguchi T, Nagano S, Kakoi H, Yokouchi M, Yamamoto T, Komiya S. A Kirschner wire as a transverse-axis guide to improve acetabular cup positioning. J Orthop Surg (Hong Kong) 2016; 24:22-6. [PMID: 27122507 DOI: 10.1177/230949901602400107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To compare cup-positioning accuracy in total hip arthroplasty (THA) with or without use of a Kirschner wire as a transverse-axis guide for pelvic alignment. METHODS Records of 18 men and 73 women (mean age, 60 years) who underwent primary THA with (n=49) or without (n=42) use of a Kirschner wire as a transverse-axis guide for pelvic alignment were reviewed. A 2.4-mm Kirschner wire as a transversea-xis guide was inserted to the anterior superior iliac spine and was parallel to a line linking the left and right anterior superior iliac spine. The safe zone for cup positioning was defined as 30º to 50° abduction and 10º to 30º anteversion. Of the 5 operative surgeons, 2 were classified as experienced (total surgical volume >300) and 3 as inexperienced (total surgical volume of <50). The proportion of patients with the cup in the safe zone was compared in patients with or without use of the transverse-axis guide and in experienced and inexperienced surgeons. RESULTS For inexperienced surgeons, the use of the transverse-axis guide significantly improved the proportion of patients with the cup in the safe zone from 90% to 100% for abduction, from 50% to 82.4% for anteversion, and from 40% to 82.4% for both. Patients with the cup inside or outside the safe zone were comparable in terms of body height, weight, BMI, subcutaneous fat thickness, incision length, and acetabular cup size. CONCLUSION The use of the transverse-axis guide improved the accuracy of cup positioning by inexperienced surgeons.
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Ijiri K, Takahashi K, Sunahara N, Taketomi E, Sakashita S, Koiso M, Komiya S. SAT0139 The preventive effect of infliximab on progression of occipito-cervical lesion in RA patients. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.3086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Tsuneyoshi Y, Tanaka M, Nagai T, Sunahara N, Matsuda T, Sonoda T, Ijiri K, Komiya S, Matsuyama T. Functional folate receptor beta-expressing macrophages in osteoarthritis synovium and their M1/M2 expression profiles. Scand J Rheumatol 2012; 41:132-40. [PMID: 22211358 DOI: 10.3109/03009742.2011.605391] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The distribution of folate receptor (FR)-β+ macrophages and their M1/M2 expression profiles were examined in osteoarthritis (OA) synovial tissues, and compared to those in rheumatoid arthritis (RA) synovial tissues and CD163+ macrophages in both OA and RA synovial tissues. METHOD The phenotypes and fluorescein isothiocyanate (FITC)-folate uptake of FR-β+ synovial macrophages were analysed by flow cytometry. The distribution of FR-β+ macrophages in OA and RA synovial tissues was examined by immunofluorescent microscopy. Tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), interleukin (IL)-10, and transforming growth factor (TGF)-β expression in FR-β+ macrophages was detected by double-immunostaining in both OA and RA synovial tissues. RESULTS FR-β+ macrophages were predominantly present in the synovial lining layer in OA patients. The proportion of CD163-FR-β+ cells in synovial mononuclear cells (MNCs) was increased in OA compared to RA synovial tissues. FR-β(high) macrophages from OA synovial tissues represented the majority of folic acid-binding cells. Although FR-β+ or CD163+ macrophages in the synovial tissues of OA and RA patients expressed a mixed pattern of M1 and M2 macrophage markers, there were more M2 markers expressing synovial macrophages in OA than in RA patients. CONCLUSIONS The distribution and M1/M2 expression profiles of FR-β+ synovial macrophages were different between OA and RA synovial tissues. Thus, the findings underscore that the M1/M2 paradigm using surface markers FR-β and CD163 is an oversimplification of macrophage subsets. Functional FR-β present on OA synovial macrophages provides a potential tool for the diagnosis and treatment of OA.
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Silva Neto MB, Blumberg G, Gozar A, Komiya S, Ando Y. Anisotropies in the optical ac and dc conductivities in lightly doped La(2 - x)Sr(x)CuO4: the role of deep and shallow acceptor states. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:215602. [PMID: 21558605 DOI: 10.1088/0953-8984/23/21/215602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We investigate the origin of the optical ac and dc conductivity anisotropies observed in the low temperature orthorhombic phase of lightly doped, untwinned La(2 - x)Sr(x)NiO(4) single crystals. We show that these anisotropies can be naturally ascribed to the emergence of two odd parity, rotational-symmetry-broken, localized impurity acceptor states, one deeper and one shallower, resulting from the trapping of doped holes by the Coulomb potential provided by the Sr ions. These two lowest-energy, p-wave-like states are split by orthorhombicity and are partially filled with holes. This leaves a unique imprint in the optical ac conductivity, which shows two distinct far-infrared continuum absorption energies corresponding to the photoionization of the deep and shallow acceptor states. Furthermore, we argue that the existence of two independent and orthogonal channels for hopping conductivity, directly associated with the two orthorhombic directions, also quantitatively explains the observed low temperature anisotropies in the dc conductivity.
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Sonier JE, Kaiser CV, Pacradouni V, Sabok-Sayr SA, Cochrane C, MacLaughlin DE, Komiya S, Hussey NE. Direct search for a ferromagnetic phase in a heavily overdoped nonsuperconducting copper oxide. Proc Natl Acad Sci U S A 2010; 107:17131-4. [PMID: 20855579 PMCID: PMC2951402 DOI: 10.1073/pnas.1007079107] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The doping of charge carriers into the CuO(2) planes of copper oxide Mott insulators causes a gradual destruction of antiferromagnetism and the emergence of high-temperature superconductivity. Optimal superconductivity is achieved at a doping concentration p beyond which further increases in doping cause a weakening and eventual disappearance of superconductivity. A potential explanation for this demise is that ferromagnetic fluctuations compete with superconductivity in the overdoped regime. In this case, a ferromagnetic phase at very low temperatures is predicted to exist beyond the doping concentration at which superconductivity disappears. Here we report on a direct examination of this scenario in overdoped La(2-x)Sr(x)CuO(4) using the technique of muon spin relaxation. We detect the onset of static magnetic moments of electronic origin at low temperature in the heavily overdoped nonsuperconducting region. However, the magnetism does not exist in a commensurate long-range ordered state. Instead it appears as a dilute concentration of static magnetic moments. This finding places severe restrictions on the form of ferromagnetism that may exist in the overdoped regime. Although an extrinsic impurity cannot be absolutely ruled out as the source of the magnetism that does occur, the results presented here lend support to electronic band calculations that predict the occurrence of weak localized ferromagnetism at high doping.
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Mangham DC, Cannon A, Li XQ, Komiya S, Gebhardt MC, Springfield DS, Rosenberg AE, Mankin HJ. p53 overexpression in Ewing's sarcoma/primitive neuroectodermal tumour is an uncommon event. Mol Pathol 2010; 48:M79-82. [PMID: 16695986 PMCID: PMC407929 DOI: 10.1136/mp.48.2.m79] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aim-To determine the presence of p53 overexpression in Ewing's sarcoma/primitive neuroectodermal tumours (ETs) and to assess whether p53 accumulation has any prognostic value.Methods-From a prospectively compiled database of 76 patients with ETs, suitable tumour tissue was available for 38. The monoclonal antibody pAb1801 was used to detect p53 nuclear protein overexpression. Results-Nuclear staining was detected in the tumours of three (8%) of the 38 patients. Where tumours stained positively, over 10% of the tumour nuclei were postively stained. All three patients whose tumours overexpressed p53 died and in a relatively short time compared with the patients who did not overexpress p53 (mean 3.7 months compared with a mean of 38.7 months in the p53 negative group).Conclusion-Overexpression of p53 in ETs is an uncommon event. Overexpression of p53 has repeatedly been shown to correlate closely with p53 point missense mutations and therefore this oncogenic event appears not to be of primary pathogenic importance in ETs. There is a tentative indication that those uncommon ETs in which p53 overexpression can be detected may be-have more aggressively.
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Schafgans AA, LaForge AD, Dordevic SV, Qazilbash MM, Padilla WJ, Burch KS, Li ZQ, Komiya S, Ando Y, Basov DN. Towards a two-dimensional superconducting state of La(2-x)Sr(x)CuO4 in a moderate external magnetic field. PHYSICAL REVIEW LETTERS 2010; 104:157002. [PMID: 20482012 DOI: 10.1103/physrevlett.104.157002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Indexed: 05/29/2023]
Abstract
We report a novel aspect of the competition and coexistence between magnetism and superconductivity in the high-T(c) cuprate La(2-x)Sr(x)CuO4 (La214). With a modest magnetic field applied H parallel c axis, we monitored the infrared signature of pair tunneling between the CuO2 planes and discovered the complete suppression of interlayer coupling in a series of underdoped La214 single crystals. We find that the in-plane superconducting properties remain intact, in spite of enhanced magnetism in the planes.
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Setoguchi T, Tanaka M, Komiya S. 9409 Inhibition of Notch pathway prevents osteosarcoma growth by regulation of cell cycle. EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)71997-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Peets DC, Hawthorn DG, Shen KM, Kim YJ, Ellis DS, Zhang H, Komiya S, Ando Y, Sawatzky GA, Liang R, Bonn DA, Hardy WN. X-ray absorption spectra reveal the inapplicability of the single-band Hubbard model to overdoped cuprate superconductors. PHYSICAL REVIEW LETTERS 2009; 103:087402. [PMID: 19792760 DOI: 10.1103/physrevlett.103.087402] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Indexed: 05/28/2023]
Abstract
X-ray absorption spectra on the overdoped high-temperature superconductors Tl2Ba2CuO(6+delta) and La(2-x)SrxCuO(4+/-delta) reveal a striking departure in the electronic structure from that of the underdoped regime. The upper Hubbard band, identified with strong correlation effects, is not observed on the oxygen K edge, while the lowest-energy prepeak gains less intensity than expected above p approximately 0.21. This suggests a breakdown of the Zhang-Rice singlet approximation and a loss of correlation effects or a significant shift in the most fundamental parameters of the system, rendering single-band Hubbard models inapplicable. Such fundamental changes suggest that the overdoped regime may offer a distinct route to understanding in the cuprates.
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Yoshida T, Hashimoto M, Ideta S, Fujimori A, Tanaka K, Mannella N, Hussain Z, Shen ZX, Kubota M, Ono K, Komiya S, Ando Y, Eisaki H, Uchida S. Universal versus material-dependent two-gap behaviors of the high-Tc cuprate superconductors: angle-resolved photoemission study of La2-xSrxCuO4. PHYSICAL REVIEW LETTERS 2009; 103:037004. [PMID: 19659310 DOI: 10.1103/physrevlett.103.037004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Indexed: 05/28/2023]
Abstract
We have investigated the doping and temperature dependences of the pseudogap and superconducting gap in the single-layer cuprate La2-xSrxCuO4 by angle-resolved photoemission spectroscopy. The results clearly exhibit two distinct energy and temperature scales, namely, the gap around (pi, 0) of magnitude Delta* and the gap around the node characterized by the d-wave order parameter Delta0. In comparison with Bi2212 having higher Tc's, Delta0 is smaller, while Delta* and T* are similar. This result suggests that Delta* and T* are approximately material-independent properties of a single CuO2 plane, in contrast to the material-dependent Delta0, representing the pairing strength.
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Tanaka M, Setoguchi T, Hirotsu M, Gao H, Sasaki H, Matsunoshita Y, Komiya S. Inhibition of Notch pathway prevents osteosarcoma growth by cell cycle regulation. Br J Cancer 2009; 100:1957-65. [PMID: 19455146 PMCID: PMC2714252 DOI: 10.1038/sj.bjc.6605060] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The study shows constitutive activation of the Notch pathway in various types of malignancies. However, it remains unclear how the Notch pathway is involved in the pathogenesis of osteosarcoma. We investigated the expression of the Notch pathway molecules in osteosarcoma biopsy specimens and examined the effect of Notch pathway inhibition. Real-time PCR revealed overexpression of Notch2, Jagged1, HEY1, and HEY2. On the other hand, Notch1 and DLL1 were downregulated in biopsy specimens. Notch pathway inhibition using γ-secretase inhibitor and CBF1 siRNA slowed the growth of osteosarcomas in vitro. In addition, γ-secretase inhibitor-treated xenograft models exhibited significantly slower osteosarcoma growth. Cell cycle analysis revealed that γ-secretase inhibitor promoted G1 arrest. Real-time PCR and western blot revealed that γ-secretase inhibitor reduced the expression of accelerators of the cell cycle, including cyclin D1, cyclin E1, E2, and SKP2. On the other hand, p21cip1 protein, a cell cycle suppressor, was upregulated by γ-secretase inhibitor treatment. These findings suggest that inhibition of Notch pathway suppresses osteosarcoma growth by regulation of cell cycle regulator expression and that the inactivation of the Notch pathway may be a useful approach to the treatment of patients with osteosarcoma.
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Ijiri K, Hida K, Yano S, Komiya S, Iwasaki Y. Traumatic spinal-cord herniation associated with pseudomeningocele after lower-thoracic nerve-root avulsion. Spinal Cord 2009; 47:829-31. [PMID: 19350043 DOI: 10.1038/sc.2009.38] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Traumatic spinal-cord herniation after nerve root avulsion is rare. We report on the first patient with spinal-cord herniation associated with pseudomeningocele in the lower conus medullaris region after nerve avulsion. CASE This 72-year-old man presented with progressive pain in the left leg and motor weakness after two traumatic accidents. Constructive interference in steady-state (CISS) imaging showed the attachment of the spinal cord to the wall of a herniated pseudomeningocele and associated syringomyelia at the level of T12. At the time of surgery, a herniated pseudomeningocele was observed. The lateral portion of the spinal cord that had herniated into the pseudomeningocele was detached from its wall; this was followed by repair of the dural defect. A redundant nerve root was observed inside the pseudomeningocele, suggesting nerve root avulsion as the primary lesion. To facilitate cerebrospinal fluid drainage from the syringomyelia, we next performed dorsal root entry zone (DREZ)tomy to the pseudomeningocele. Postoperatively, he manifested significant clinical improvement. CONCLUSIONS This is the first report of spinal cord herniation after nerve root avulsion in the conus medullaris region. CISS imaging is highly useful for the demonstration of spinal cord herniation, syringomyelia and pseudomeningocele. To restore neurological function in patients with progressive symptoms, we recommend surgical treatment.
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Komiya S, Tsukada I. Doping evolution of the electronic specific heat coefficient in slightly-doped La2-xSrxCuO4single crystals. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/150/5/052118] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sonier JE, Ilton M, Pacradouni V, Kaiser CV, Sabok-Sayr SA, Ando Y, Komiya S, Hardy WN, Bonn DA, Liang R, Atkinson WA. Inhomogeneous magnetic-field response of YBa2Cu3Oy and La2-xSrxCuO4 persisting above the bulk superconducting transition temperature. PHYSICAL REVIEW LETTERS 2008; 101:117001. [PMID: 18851316 DOI: 10.1103/physrevlett.101.117001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Indexed: 05/26/2023]
Abstract
We report that in YBa2Cu3Oy and La2-xSrxCuO4 there is a spatially inhomogeneous response to the magnetic field for temperatures T extending well above the bulk-superconducting transition temperature Tc. An inhomogeneous magnetic response is observed above Tc even in ortho-II YBa2Cu3O6.50, which has highly ordered doping. The degree of the field inhomogeneity above Tc tracks the hole-doping dependences of both Tc and the density of the superconducting carriers below Tc, and therefore is apparently coupled to superconductivity.
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Hill JP, Blumberg G, Kim YJ, Ellis DS, Wakimoto S, Birgeneau RJ, Komiya S, Ando Y, Liang B, Greene RL, Casa D, Gog T. Observation of a 500 meV collective mode in La2-xSrxCuO4 and Nd2CuO4 using resonant inelastic X-ray scattering. PHYSICAL REVIEW LETTERS 2008; 100:097001. [PMID: 18352743 DOI: 10.1103/physrevlett.100.097001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Indexed: 05/26/2023]
Abstract
Utilizing resonant inelastic x-ray scattering, we report a previously unobserved mode in the excitation spectrum of La2-xSrxCuO4 and Nd2CuO4 at 500 meV. The mode is peaked around the (pi, 0) point in reciprocal space and is observed to soften, and broaden, away from this point. Samples with x=0, 0.01, 0.05, and 0.17 were studied. The new mode is found to be rapidly suppressed with increasing Sr content and is absent at x=0.17, where it is replaced by a continuum of excitations. This mode is only observed when the incident x-ray polarization is normal to the CuO planes.
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Tofuku K, Koga H, Yamamoto T, Yone K, Komiya S. Spinal cord infarction following endoscopic variceal ligation. Spinal Cord 2007; 46:241-2. [PMID: 17579614 DOI: 10.1038/sj.sc.3102092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN A case report of spinal cord infarction following endoscopic variceal ligation. OBJECTIVES To describe an exceedingly rare case of spinal cord infarction following endoscopic variceal ligation. SETTING Department of Orthopaedic Surgery, Kagoshima, Japan. METHODS A 75-year-old woman with cirrhosis caused by hepatitis C virus, who was admitted to our hospital for the treatment of esophageal varices, experienced numbness of the hands and lower extremities bilaterally following an endoscopic variceal ligation procedure. Sensory and motor dysfunction below C6 level progressed rapidly, resulting in inability to move the lower extremities the following day. Magnetic resonance imaging of the spine revealed abnormal spinal cord signal on T2-weighted images from approximately C6 through T5 levels, which was diagnosed as spinal cord infarction. RESULTS The patient underwent hyperbaric oxygen treatment. Her symptoms and signs related to spinal cord infarction gradually remitted, and nearly complete disappearance of neurological deficits was noted within 3 months after the start of treatment. CONCLUSION We speculate that the pathogenesis of the present case may have involved congestion of the abdominal-epidural-spinal cord venous network owing to ligation of esophageal varices and increased thoracoabdominal cavity pressure.
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Kang HJ, Dai P, Campbell BJ, Chupas PJ, Rosenkranz S, Lee PL, Huang Q, Li S, Komiya S, Ando Y. Microscopic annealing process and its impact on superconductivity in T'-structure electron-doped copper oxides. NATURE MATERIALS 2007; 6:224-9. [PMID: 17310138 DOI: 10.1038/nmat1847] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 01/12/2007] [Indexed: 05/14/2023]
Abstract
High-transition-temperature superconductivity arises in copper oxides when holes or electrons are doped into the CuO(2) planes of their insulating parent compounds. Whereas hole doping quickly induces metallic behaviour and superconductivity in many cuprates, electron doping alone is insufficient in materials such as R(2)CuO(4) (R is Nd, Pr, La, Ce and so on), where it is necessary to anneal an as-grown sample in a low-oxygen environment to remove a tiny amount of oxygen in order to induce superconductivity. Here we show that the microscopic process of oxygen reduction repairs Cu deficiencies in the as-grown materials and creates oxygen vacancies in the stoichiometric CuO(2) planes, effectively reducing disorder and providing itinerant carriers for superconductivity. The resolution of this long-standing materials issue suggests that the fundamental mechanism for superconductivity is the same for electron- and hole-doped copper oxides.
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Tofuku K, Koga H, Yone K, Komiya S. Hypoplasia of the atlas causing cervical myelopathy with situs inversus totalis. Spinal Cord 2007; 45:806-8. [PMID: 17297494 DOI: 10.1038/sj.sc.3102042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
STUDY DESIGN A case report of myelopathic hypoplasia of the atlas with situs inversus totalis. OBJECTIVES To describe a case of cervical myelopathy caused by hypoplasia of the atlas with situs inversus totalis, and to briefly review the pertinent literature. SETTING Department of Orthopaedic Surgery, Kagoshima, Japan. METHODS The history, results of examination, and findings of radiographic imaging studies for a 56-year-old man with a 10-year history of progressive myelopathy who presented to our hospital are described. RESULTS Imaging studies revealed congenital hypoplasia of the atlas, ossification of the posterior longitudinal ligament at the levels of C3-C4, and situs inversus totalis. He underwent laminectomy of the atlas and laminoplasty of C3-C7 for decompression of the spinal cord. Operative intervention resulted in significant neurological improvement and relief of occipital neuralgia. CONCLUSION To our knowledge, no case of myelopathic hypoplasia of the atlas with situs inversus totalis has previously been described. When encountering inherited disorders such as situs inversus totalis, a thorough search must be made for anomalies of the craniovertebral junction.
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Kagawa T, Abematsu M, Fukuda S, Inoue T, Takebayashi H, Komiya S, Taga T. [P134]: BFGF endows dorsal telencephalic neural progenitors with ability to differentiate into oligodendrocytes but not GABAergic neurons. Int J Dev Neurosci 2006. [DOI: 10.1016/j.ijdevneu.2006.09.196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Kordyuk AA, Borisenko SV, Zabolotnyy VB, Geck J, Knupfer M, Fink J, Büchner B, Lin CT, Keimer B, Berger H, Pan AV, Komiya S, Ando Y. Constituents of the quasiparticle spectrum along the nodal direction of high-Tc cuprates. PHYSICAL REVIEW LETTERS 2006; 97:017002. [PMID: 16907398 DOI: 10.1103/physrevlett.97.017002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Indexed: 05/11/2023]
Abstract
Applying the Kramers-Kronig consistent procedure, developed earlier, we investigate in detail the formation of the quasiparticle spectrum along the nodal direction of high-Tc cuprates. The heavily discussed "70 meV kink" on the renormalized dispersion exhibits a strong temperature and doping dependence when purified from structural effects such as bilayer splitting, diffraction replicas, etc. This dependence is well understood in terms of fermionic and bosonic constituents of the self-energy. The latter follows the evolution of the spin-fluctuation spectrum, emerging below some doping dependent temperature and sharpening below Tc, and is mainly responsible for the formation of the kink in question.
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Wilson SD, Li S, Woo H, Dai P, Mook HA, Frost CD, Komiya S, Ando Y. High-energy spin excitations in the electron-doped superconductor Pr(0.88)LaCe(0.12)CuO(4-delta) with T(c) = 21 K. PHYSICAL REVIEW LETTERS 2006; 96:157001. [PMID: 16712186 DOI: 10.1103/physrevlett.96.157001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Indexed: 05/09/2023]
Abstract
We use high-resolution inelastic neutron scattering to study the low-temperature magnetic excitations of the electron-doping superconductor Pr(0.88)LaCe(0.12)CuO(4-delta) (T(c) = 21 +/- 1 K) over a wide energy range (4 meV < or = homega < or = 330 meV). The effect of electron doping is to cause a wave vector (Q) broadening in the low-energy (homega < or = 80 meV) commensurate spin fluctuations at (0.5, 0.5) and to suppress the intensity of spin-wave-like excitations at high energies (homega > or = 100 meV). This leads to a substantial redistribution in the spectrum of the local dynamical spin susceptibility chi''(omega), and reveals a new energy scale similar to that of the lightly hole-doped YB2Cu3O(6.353) (T(c) = 18 K).
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Sun XF, Ono S, Abe Y, Komiya S, Segawa K, Ando Y. Electronic inhomogeneity and breakdown of the universal thermal conductivity of cuprate superconductors. PHYSICAL REVIEW LETTERS 2006; 96:017008. [PMID: 16486505 DOI: 10.1103/physrevlett.96.017008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Indexed: 05/06/2023]
Abstract
We report systematic, high-precision measurements of the low-T (down to 70 mK) thermal conductivity kappa of YBa2Cu3O(y), La(2-x)Sr(x)CuO4, and Bi2Sr2CaCu2O(8+delta). Careful examinations of the Zn- and hole-doping dependences of the residual thermal conductivity kappa0/T, as well as the in-plane anisotropy of kappa0/T in Bi2Sr2CaCu2O(8+delta), indicate a breakdown of the universal thermal conductivity, a notable theoretical prediction for d-wave superconductors. Our results point to an important role of electronic inhomogeneities, which are not considered in the standard perturbation theory for thermal conductivity, in the underdoped to optimally doped regime.
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Nagano S, Oshika H, Fujiwara H, Komiya S, Kosai K. An efficient construction of conditionally replicating adenoviruses that target tumor cells with multiple factors. Gene Ther 2006; 12:1385-93. [PMID: 15877049 DOI: 10.1038/sj.gt.3302540] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Despite the enormous potential of conditionally replicating adenoviruses (CRAs), the time-consuming and laborious methods required to construct CRAs have hampered both the development of CRAs that can specifically target tumors with multiple factors (m-CRA) and the efficient analysis of diverse candidate CRAs. Here, we present a novel method for efficiently constructing diverse m-CRAs. Elements involving viral replication, therapeutic genes, and adenoviral backbones were separately introduced into three plasmids of P1, P2, and P3, respectively, which comprised different antibiotic resistant genes, different ori, and a single loxP (H) sequence. Independently constructed plasmids were combined at 100% accuracy by transformation with originally prepared Cre and specific antibiotics in specific Escherichia coli; transfection of the resulting P1+2+3 plasmids into 293 cells efficiently generated m-CRAs. Moreover, the simultaneous generation of diverse m-CRAs was achieved at 100% accuracy by handling diverse types of P1+2 and P3. Alternatively, co-transfection of P1+3 and P2 plasmids into Cre-expressing 293 cells directly generated m-CRA with therapeutic genes. Thus, our three-plasmid system, which allows unrestricted construction and efficient fusion of individual elements, should expedite the process of generating, modifying, and testing diverse m-CRAs for the development of the ideal m-CRA for tumor therapy.
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