578 research outputs found

    DNA Methylation Status of the Methylenetetrahydrofolate Reductase Gene is associated with Depressive Symptoms in Japanese Workers: A Cross-Sectional Study

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    Abstract Background: Polymorphisms in methylenetetrahydrofolate reductase (MTHFR) gene, that is considered to be the most important genetic determinant of blood homocysteine concentration, are associated with various diseases, including psychiatric disorders. However, the epigenetic factors influencing on the transcription and expression of this gene are unclear. The current study aims to detect the relationship between epigenetic factor-DNA methylation status, on the human MTHFR gene and depressive symptoms in Japanese workers. Methods: 774 DNA samples were extracted from saliva samples collected from subjects recruited for a mental health study, and an Illumina Human Methylation 450K Microarray Assay was used to examine DNA methylation profile across the human MTHFR gene. Depressive symptoms were determined by K6 questionnaire. Four independent DNA pools were created based on K6 scores, and the methylation levels were compared among the pools. Results: The DNA methylation level was lower in subjects with higher degrees of depression for both the entire gene (p=2.10×1

    Fermionic R-Operator and Algebraic Structure of 1D Hubbard Model: Its application to quantum transfer matrix

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    The algebraic structure of the 1D Hubbard model is studied by means of the fermionic R-operator approach. This approach treats the fermion models directly in the framework of the quantum inverse scattering method. Compared with the graded approach, this approach has several advantages. First, the global properties of the Hamiltonian are naturally reflected in the algebraic properties of the fermionic R-operator. We want to note that this operator is a local operator acting on fermion Fock spaces. In particular, SO(4) symmetry and the invariance under the partial particle hole transformation are discussed. Second, we can construct a genuinely fermionic quantum transfer transfer matrix (QTM) in terms of the fermionic R-operator. Using the algebraic Bethe Ansatz for the Hubbard model, we diagonalize the fermionic QTM and discuss its properties.Comment: 22 pages, no figure

    Critical Properties in Dynamical Charge Correlation Function for the One-Dimensional Mott Insulator

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    Critical properties in the dynamical charge correlation function for the one-dimensional Mott insulator are studied. By properly taking into account {\it the final-state interaction} between the charge and spin degrees of freedom, we find that the edge singularity in the charge correlation function is governed by massless spinon excitations, although it is naively expected that spinons do not directly contribute to the charge excitation over the Hubbard gap. We obtain the momentum-dependent anomalous critical exponent by applying the finite-size scaling analysis to the Bethe ansatz solution of the half-filled Hubbard model.Comment: 7 pages, REVTe

    Exact Solution of Heisenberg-liquid models with long-range coupling

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    We present the exact solution of two Heisenberg-liquid models of particles with arbitrary spin SS interacting via a hyperbolic long-range potential. In one model the spin-spin coupling has the simple antiferromagnetic Heisenberg exchange form, while for the other model the interaction is of the ferromagnetic Babujian-Takhatajan type. It is found that the Bethe ansatz equations of these models have a similar structure to that of the Babujian-Takhatajan spin chain. We also conjecture the integrability of a third new spin-lattice model with long-range interaction.Comment: 7pages Revte

    Universal temperature dependence of electron number in one-dimensional Hubbard model

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    We investigate the temperature region in which a Tomonaga-Luttinger liquid (TLL) description of the charge sector of the one-dimensional Hubbard model is valid. By using the thermodynamic Bethe ansatz method, electron number is calculated at finite temperatures and fixed chemical potential. We observe maximum electron number as a function of temperature close to the chemical potential of the upper critical value that corresponds to half filling. As the chemical potential approaches the upper critical value from below, the temperature (TM)(T_{\rm M}) at which the electron number shows its maximum asymptotically approaches a universal relation. We show that, below the energy corresponding to TMT_{\rm M}, the charge excitation spectrum nearly obeys a linear dispersion relation. The results demonstrate that TMT_{\rm M} marks the important temperature below which TLL is realized.Comment: 4 pages, 4 figure

    Fine Structure and Fractional Aharonov-Bohm Effect

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    We find a fine structure in the Aharonov-Bohm effect, characterized by the appearence of a new type of periodic oscillations having smaller fractional period and an amplitude, which may compare with the amplitude of the conventional Aharonov-Bohm effect. Specifically, at low density or strong coupling on a Hubbard ring can coexist along with the conventional Aaronov-Bohm oscillations with the period equal to an integer, measured in units of the elementary flux quantum, two additional oscillations with periods 1/N1/N and M/NM/N. The integers NN and MM are the particles number and the number of down-spin particles, respectively. {}From a solution of the Bethe ansatz equations for NN electrons located on a ring in a magnetic field we show that the fine structure is due to electron-electron and Zeeman interactions. Our results are valid in the dilute density limit and for an arbitrary value of the Hubbard repulsion UUComment: 40 pages (Latex,Revtex) 12 figures by request, in Technical Reports of ISSP , Ser. A, No.2836 (1994

    Anaplastic carcinoma of the pancreas producing granulocyte-colony stimulating factor: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The granulocyte-colony stimulating factor-producing tumor was first reported in 1977, however, anaplastic pleomorphic type carcinoma of the pancreas producing granulocyte-colony stimulating factor is still rare.</p> <p>Case presentation</p> <p>A 63-year-old man was admitted to our hospital with body weight loss (-10 kg during months) and upper abdominal pain from 3 weeks. Abdominal computed tomography demonstrated a pancreatic tumor 10 cm in size and multiple low-density areas in the liver. On admission, the peripheral leukocyte count was elevated to 91,500/mm<sup>3 </sup>and the serum concentration of granulocyte-colony stimulating factor was 134 pg/mL (normal, < 18.1 pg/mL). Based on liver biopsy findings, the tumor was classified as an anaplastic pleomorphic-type carcinoma. Immunohistochemical staining showed that pancreatic carcinoma cells were positive for granulocyte-colony stimulating factor. The patient developed interstitial pneumonia, probably caused by granulocyte-colony stimulating factor, and died 11 days after admission.</p> <p>Conclusion</p> <p>This is a rare case report of anaplastic pleomorphic-type carcinoma of the pancreas producing granulocyte-colony stimulating factor and confirmed by immunohistochemistry.</p
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