Observation of spin-space quantum transport induced by an atomic quantum point contact.

Quantum transport is ubiquitous in physics. So far, quantum transport between terminals has been extensively studied in solid state systems from the fundamental point of views such as the quantized conductance to the applications to quantum devices. Recent works have demonstrated a cold-atom analog of a mesoscopic conductor by engineering a narrow conducting channel with optical potentials, which opens the door for a wealth of research of atomtronics emulating mesoscopic electronic devices and beyond. Here we realize an alternative scheme of the quantum transport experiment with ytterbium atoms in a two-orbital optical lattice system. Our system consists of a multi-component Fermi gas and a localized impurity, where the current can be created in the spin space by introducing the spin-dependent interaction with the impurity. We demonstrate a rich variety of localized-impurity-induced quantum transports, which paves the way for atomtronics exploiting spin degrees of freedom.

Synthesis and evaluation of aminopyridine derivatives as potential BACE1 inhibitors.

To identify a new non-peptidyl BACE1 inhibitor, we focused on the aminopyridine structure, which binds to the active sites of BACE1. Synthesis of aminopyridine derivatives and evaluation of inhibitory activity against rBACE1 are described. The 2-aminopyridine moiety and/or 3-methoxybenzaldehyde could be converted to terminal acetylene derivatives by the Sonogashira method. Sonogashira or Glaser cross-coupling reactions with the corresponding derivatives followed by hydrogenation could derive the designed compounds. Although inhibitory activities of the synthetic compounds against rBACE1 were weak, the aminopyridine motif has potential as a BACE1 inhibitor.

[The influence on the static visual field of peripapillary chorioretinal atrophy--relation to refractive error].

PURPOSE: To investigate the influence of refractive error on white-on-white perimetry(W-on-W) in myopic subjects according to the presence or absence of peripapillary chorioretinal atrophy (PPA). SUBJECTS AND METHODS: W-on-W perimetry was performed on 57 normal volunteers whose fundus photography was clear and the presence or absence of PPA was distinct. We divided the 57 normal volunteers into a PPA-positive group and a PPA-negative group, and investigated the influence of refractive error. RESULTS: Mean deviation (MD) reduction was significantly correlated with the degree of myopia in the myopic group, whereas there was no significant correlation with refractive error in the control group. In the myopic group, MD reduction was significantly correlated with the degree of myopia in the PPA-positive group, whereas there was no significant correlation between refractive error and MD in the PPA-negative group. In the control group, there was no significant correlation between refractive error and MD in either the PPA-positive group or the PPA-negative group. CONCLUSIONS: MD reduction was significantly correlated with the degree of myopia in myopic subjects, and was more remarkable in PPA-positive subjects.

Influence of clinical factors on blue-on-yellow perimetry for diabetic patients without retinopathy: comparison with white-on-white perimetry.

PURPOSE: To investigate the influence of clinical factors (duration of diabetes mellitus, fasting blood sugar level, fructosamine concentration, and hemoglobin A1c) on blue-on-yellow (B-on-Y) perimetry compared with white-on-white (W-on-W) perimetry for diabetics without retinopathy. METHODS: Both B-on-Y perimetry and W-on-W perimetry were performed for 33 diabetics without retinopathy. Thirty-three subjects with healthy eyes served as age-matched controls. RESULTS: For both diabetic patients and controls, mean deviation (MD) and corrected pattern SD of perimetry showed no difference irrespective of B-on-Y or W-on-W perimetry. For diabetics, MD of B-on-Y perimetry decreased in proportion to the morbid period with diabetes mellitus, with the same being true with deterioration of the clinical factors. Multiple regression analysis disclosed no differences in MD of clinical factors for W-on-W perimetry, despite the duration of diabetes mellitus exerting a significant influence on MD of B-on-Y perimetry. CONCLUSION: Even at the premorbid stage of diabetic retinopathy, longer duration of diabetes mellitus and longer persistence of poorly controlled diabetes mellitus are associated with an insidious progress of dysfunction in the retinal blue cone system.

[The influence on the static visual field of peripapillary chorioretinal atrophy--relation to axial length].

PURPOSE: To investigate the influence of axial length on white-on-white (W-on-W) perimetry and blue-on-yellow (B-on-Y) perimetry in myopic subjects according to the presence or absence of peripapillary chorioretinal atrophy (PPA). MATERIALS AND METHODS: Both B-on-Y and W-on-W perimetry were performed on 64 normal volunteers whose fundus photography was clear, and the presence or absence of PPA was distinct. We divided the 64 normal volunteers into a PPA group and a no-PPA group, and investigated the influence of axial length on both types of perimetry. RESULTS: As axial length extended in all cases and in the PPA group, mean deviation (MD) decreased significantly in both B-on-Y and W-on-W perimetry. There was no significant difference in the no-PPA group. In the PPA group, the retinal sensitivity decreased significantly at 22 test points in B-on-Y, as axial length extended; and this decrease occurred at 12 test points in W-on-W perimetry. These points were located mainly around the Mariotte blind spot, central points, and the area of Bjerrum. In the no-PPA group, the retinal sensitivity decreased significantly at only two test points in B-on-Y perimetry, but no decrease occurred at these test points in W-on-W perimetry. CONCLUSIONS: We should consider the presence of PPA and the influence of axial length in the interpretation of the results of W-on-W and B-on-Y perimetry.

Synthesis of Vinylene-Co,N-Linked Multi(porphyrin)s by the Addition of Free-Base Porphyrins to a C(2)H(2) Complex of Cobalt(III) Porphyrin and Their Oxidative Rearrangement to Vinylene-N,N'-Linked Multi(porphyrin)s.

The nucleophilic addition reaction of a pyrrole nitrogen of free-base porphyrins to a pi-complexed acetylene ligand in a cationic Co(III) porphyrin intermediate afforded good yields of vinylene-Co,N'-linked bis(porphyrin)s, (Por)Co(III)-CH=CH-(N-Por)H(2). N-substituted porphyrin free bases are N-vinylated regioselectively at the pyrrole adjacent to the original N-substituted pyrrole in this reaction. Tris- and tetrakis(porphyrin)s have been prepared by reacting a vinylene-N,N'-linked bis(meso-tetraarylporphyrin) with (OEP)Co(III)(H(2)O)(2)ClO(4) (OEP: octaethylporphyrin dianion) and acetylene. The tetrakis(porphyrin) proved to be a 1:1 mixture of C(i)()- and C(2)-symmetric regioisomers. These organometallic Co(III) complexes underwent facile oxidative migration of the Co-bound vinyl group to a porphyrin pyrrole nitrogen when treated with Fe(III) salts or HClO(4) to provide moderate to good yields of Co(II) vinylene-N,N'-linked multi(porphyrin) complexes. (Vinylene-N,N')bis(porphyrin) free bases with combinations of different porphyrins have been obtained by this procedure. The homobinuclear (2Co(II), 2Cu(II), and 2Zn(II)) and heterobinuclear (Co(II)Cu(II) and Co(II)Zn(II)) complexes have been prepared and characterized spectroscopically. The single-crystal X-ray analysis of (CH=CH-N,N')[(OEP)Co(II)Cl][(TPP)Zn(II)Cl] (TPP: meso-tetraphenylporphyrin dianion) showed a face-to-face structure with an average inter-ring separation of 4.39 Å (triclinic P&onemacr;; Z = 2; a = 14.806(4), b = 18.703(10), c = 13.796(3) Å, alpha = 97.69(3), beta = 99.57(2), gamma = 96.74(3) degrees ).