1,128 research outputs found

    Significance of myocardial tenascin-C expression in left ventricular remodelling and long-term outcome in patients with dilated cardiomyopathy

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    Aim Dilated cardiomyopathy (DCM) has a variety of causes, and no useful approach to predict left ventricular (LV) remodelling and long-term outcome has yet been established. Myocardial tenascin-C (TNC) is known to appear under pathological conditions, possibly to regulate cardiac remodelling. The aim of this study was to clarify the significance of myocardial TNC expression in LV remodelling and the long-term outcome in DCM. Methods and results One hundred and twenty-three consecutive DCM patients who underwent endomyocardial biopsy for initial diagnosis were studied. Expression of TNC in biopsy sections was analysed immunohistochemically to quantify the ratio of the TNC-positive area to the whole myocardial tissue area (TNC area). Clinical parameters associated with TNC area were investigated. The patients were divided into two groups based on receiver operating characteristic analysis of TNC area to predict death: high TNC group with TNC area ≥2.3% (22 patients) and low TNC group with TNC area <2.3% (101 patients). High TNC was associated with diabetes mellitus. Comparing echocardiographic findings between before and 9 months after endomyocardial biopsy, the low TNC group was associated with decreased LV end-diastolic diameter and increased LV ejection fraction, whereas the high TNC group was not. Survival analysis revealed a worse outcome in the high TNC group than in the low TNC group (P < 0.001). Multivariable Cox regression analysis revealed that TNC area was independently associated with poor outcome (HR = 1.347, P = 0.032). Conclusions Increased myocardial TNC expression was associated with worse LV remodeling and long-term outcome in DCM

    Drug review process advancement and required manufacturer and contract research oraganization responses

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    \ua9 2024 The Japanese Society of Toxicologic Pathology.The United States Senate passed the “FDA Modernization Act 2.0.” on September 29, 2022. Although the effectiveness of this Bill, which aims to eliminate the mandatory use of laboratory animals in new drug development, is limited, it represents a significant trend that will change the shape of drug applications in the United States and other countries. However, pharmaceutical companies have not taken major steps towards the complete elimination of animal testing from the standpoint of product safety, where they prioritize patient safety. Nonetheless, society is becoming increasingly opposed to animal testing, and efforts will be made to use fewer animals and conduct fewer animal tests as a natural and reasonable response. These changes eventually alter the shape of new drug applications. Based on the assumption that fewer animal tests will be conducted or fewer animals will be used in testing, this study explored bioinformatics and new technologies as alternatives to compensate for reduced information and provide a picture of how future new drug applications may look. The authors also discuss the directions that pharmaceutical companies and nonclinical contract research organizations should adopt to promote the replacement, reduction, and refinement of animals used in research, teaching, testing, and exhibitions

    Important Roles of Te 5p and Ir 5d Spin-orbit Interactions on the Multi-band Electronic Structure of Triangular Lattice Superconductor Ir1-xPtxTe2

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    We report an angle-resolved photoemission spectroscopy (ARPES) study on a triangular lattice superconductor Ir1x_{1-x}Ptx_{x}Te2_2 in which the Ir-Ir or Te-Te bond formation, the band Jahn-Teller effect, and the spin-orbit interaction are cooperating and competing with one another. The Fermi surfaces of the substituted system are qualitatively similar to the band structure calculations for the undistorted IrTe2_2 with an upward chemical potential shift due to electron doping. A combination of the ARPES and the band structure calculations indicates that the Te 5p5p spin-orbit interaction removes the px/pyp_x/p_y orbital degeneracy and induces px±ipyp_x \pm ip_y type spin-orbit coupling near the A point. The inner and outer Fermi surfaces are entangled by the Te 5p5p and Ir 5d5d spin-orbit interactions which may provide exotic superconductivity with singlet-triplet mixing.Comment: 10 pages, 4 figure

    An energy scale directly related to superconductivity in the high-TcT_c cuprate superconductors: Universality from the Fermi arc picture

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    We have performed a temperature dependent angle-resolved photoemission spectroscopy (ARPES) study of the tri-layer high-TcT_c cuprate superconductor (HTSC) Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta} (Bi2223), and have shown that the \textquotedblleft effective\textquotedblright superconducting (SC) gap Δsc\Delta_{\rm{sc}} defined at the end point of the Fermi arc and the TcT_c (= 110 K) approximately satisfies the weak-coupling BCS-relationship 2Δsc\Delta_{\rm{sc}} = 4.3kBTck_{\rm{B}}T_c. Combining this result with previous ARPES results on single- and double-layer cuprates, we show that the relationship between 2Δsc\Delta_{\rm{sc}} = 4.3kBTck_{\rm{B}}T_c holds for various HTSCs. Furthermore, at TT \sim TcT_c, the quasi-patricle width at the end point of the Fermi arc is found to coincide with Δsc\Delta_{\rm{sc}}, consistent with the context of Planckian dissipation.Comment: 5 pages, 4 figure

    Electronic structure reconstruction by orbital symmetry breaking in IrTe2

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    We report an angle-resolved photoemission spectroscopy (ARPES) study on IrTe2 which exhibits an interesting lattice distortion below 270 K and becomes triangular lattice superconductors by suppressing the distortion via chemical substitution or intercalation. ARPES results at 300 K show multi-band Fermi surfaces with six-fold symmetry which are basically consistent with band structure calculations. At 20 K in the distorted phase, whereas the flower shape of the outermost Fermi surface does not change from that at 300 K, topology of the inner Fermi surfaces is strongly modified by the lattice distortion. The Fermi surface reconstruction by the distortion depends on the orbital character of the Fermi surfaces, suggesting importance of Ir 5d and/or Te 5p orbital symmetry breaking.Comment: 4pages, 4figure

    Orbital Degeneracy and Peierls Instability in Triangular Lattice Superconductor Ir1x_{1-x}Ptx_xTe2_2

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    We have studied electronic structure of triangular lattice Ir1x_{1-x}Ptx_xTe2_2 superconductor using photoemission spectroscopy and model calculations. Ir 4f4f core-level photoemission spectra show that Ir 5d5d t2gt_{2g} charge modulation established in the low temperature phase of IrTe2_2 is suppressed by Pt doping. This observation indicates that the suppression of charge modulation is related to the emergence of superconductivity. Valence-band photoemission spectra of IrTe2_2 suggest that the Ir 5d5d charge modulation is accompanied by Ir 5d5d orbital reconstruction. Based on the photoemission results and model calculations, we argue that the orbitally-induced Peierls effect governs the charge and orbital instability in the Ir1x_{1-x}Ptx_xTe2_2.Comment: 5 pages,4 figure

    Effect of electron-phonon coupling in the ARPES spectra of the tri-layer cuprate Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta}

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    Angle-resolved photoemission spectroscopy using tunable low energy photons allows us to study the quasi-particle (QP) dispersions of the inner and outer CuO2 planes (IP and OP) separately in the tri-layer cuprate Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta} (Bi2223). The kink energy of the OP band is \sim 70 meV, as observed in various high-TcT_c cuprates, while that of the IP band is as large as 100 meV in the superconducting (SC) state. This large kink energy is attributed to the \sim 35 meV buckling mode plus the large (\sim 60 meV) SC gap of IP. The IP band also shows a weak kink feature at 70 meV in the SC state. The latter feature can be explained either by the 70 meV half-breathing mode or by the \sim 35 meV buckling-phonon mode plus the \sim 40 meV SC gap of OP if interlayer scattering of QP is involved.Comment: 5 pages, 2 figure
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