Tohoku University

About: Tohoku University is a education organization based out in Sendai, Japan. It is known for research contribution in the topics: Magnetization & Alloy. The organization has 72116 authors who have published 170791 publications receiving 3941714 citations. The organization is also known as: Tōhoku daigaku.

Cloning of the gamma chain of the human IL-2 receptor

Abstract: A third subunit, the gamma chain, of the human interleukin-2 receptor (IL-2R) was identified, and a complementary DNA clone encoding this member of the cytokine receptor family was isolated. The gamma chain is necessary for the formation of the high- and intermediate-affinity receptors, which consists of alpha beta gamma heterotrimers and beta gamma heterodimers, respectively. The IL-2R on murine fibroblastoid cells can be internalized after binding IL-2 only if the gamma chain is present; alpha and beta are insufficient for internalization. Thus, the gamma chain is an indispensable component of the functional IL-2R.

Destruction of the Fermi surface in underdoped high- T c superconductors

Abstract: The Fermi surface—the set of points in momentum space describing gapless electronic excitations—is a central concept in the theory of metals. In this context, the normal ‘metallic’ state of the optimally doped high-temperature superconductors is not very unusual: above the superconducting transition temperature, Tc, there is evidence for a large Fermi surface1,2,3, despite the absence of well-defined elementary excitations. In contrast, the normal state of underdoped high-temperature superconductors differs in that there is evidence for a ‘pseudogap’ above Tc (4–7). Here we examine, using angle-resolved photoemission spectroscopy, the temperature dependence of the Fermi surface in underdoped Bi2Sr2CaCu2O8+δ. We find that, on cooling the sample, the pseudogap opens up at different temperatures for different points in momentum space. This leads to an initial breakup of the Fermi surface, at a temperature T*, into disconnected arcs, which then shrink with decreasing temperature before collapsing to the point nodes of the superconducting ground state below Tc. This unusual behaviour, where the Fermi surface does not form a continuous contour in momentum space as in conventional metals, is unprecedented in that it occurs in the absence of long-range order. Moreover, although the superconducting gap below Tc evolves smoothly into the pseudogap above Tc, the pseudogap differs in its unusual temperature-dependent anisotropy, implying an intimate but non-trivial relationship between the pseudogap and the superconducting gap.

Experimental realization of a topological crystalline insulator in SnTe

Abstract: A topological insulator has surface metallic states that are topologically protected by time-reversal symmetry. Tin telluride is now shown to be a ‘topological crystalline insulator’, in which the surface metallic state is instead protected by the mirror symmetry of the crystal.

The anomalous Hall effect and magnetic monopoles in momentum space.

Abstract: Efforts to find the magnetic monopole in real space have been made in cosmic rays and in particle accelerators, but there has not yet been any firm evidence for its existence because of its very heavy mass, ∼10 16 giga–electron volts We show that the magnetic monopole can appear in the crystal momentum space of solids in the accessible low-energy region (∼01 to 1 electron volts) in the context of the anomalous Hall effect We report experimental results together with first-principles calculations on the ferromagnetic crystal SrRuO 3 that provide evidence for the magnetic monopole in the crystal momentum space

Pirfenidone in idiopathic pulmonary fibrosis

Abstract: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease without proven effective therapy. A multicentre, double-blind, placebo-controlled, randomised phase III clinical trial was conducted in Japanese patients with well-defined IPF to determine the efficacy and safety of pirfenidone, a novel antifibrotic oral agent, over 52 weeks. Of 275 patients randomised (high-dose, 1,800 mg x day(-1); low-dose, 1,200 mg x day(-1); or placebo groups in the ratio 2:1:2), 267 patients were evaluated for the efficacy of pirfenidone. Prior to unblinding, the primary end-point was revised; the change in vital capacity (VC) was assessed at week 52. Secondary end-points included the progression-free survival (PFS) time. Significant differences were observed in VC decline (primary end-point) between the placebo group (-0.16 L) and the high-dose group (-0.09 L) (p = 0.0416); differences between the two groups (p = 0.0280) were also observed in the PFS (the secondary end-point). Although photosensitivity, a well-established side-effect of pirfenidone, was the major adverse event in this study, it was mild in severity in most of the patients. Pirfenidone was relatively well tolerated in patients with IPF. Treatment with pirfenidone may decrease the rate of decline in VC and may increase the PFS time over 52 weeks. Additional studies are needed to confirm these findings.