Satoh, K. H., Hiraishi, M., Miyazaki, M., Takeshita, S., Koda, A., Kadono, R., ...
A weakening of superconductivity upon substitution of Cu by Zn (0.5~1 %) is observed in a high-T_c cuprate, Ca_{2-x}Na_xCuO2Cl2, near the hole concentration of 1/8 per Cu. The superconducting...
Mesoscopic Phase Coherence in a Quantum Spin Fluid (2008)
Xu, Guangyong, Broholm, C., Soh, Yeong-Ah, Aeppli, G., DiTusa, J. F., Chen, Ying, ...
Mesoscopic quantum phase coherence is important because it improves the prospects for handling quantum degrees of freedom in technology. Here we show that the development of such coherence can be...
Studies on ac losses in $Bi_2Sr_2CaCu_2O_8$ single crystals (2007)
Chockalingam, SP, Sarangi, S, Bhat, SV, Oka, K, Nishihara, Y
Using a novel technique of measuring absolute ac losses at radio frequencies, the temperature, magnetic field and angle dependence of rf losses in superconducting single crystals of...
Studies on ac losses in $Bi_2Sr_2CaCu_2O_8$ single crystals (2007)
Chockalingam, SP, Sarangi, S, Bhat, SV, Oka, K, Nishihara, Y
Using a novel technique of measuring absolute ac losses at radio frequencies, the temperature, magnetic field and angle dependence of rf losses in superconducting single crystals of...
Mitsumoto, M., Jahanara, B., Matsuda, T., Oka, K., Bisikalo, D. V., Kilpio, E. Yu., ...
The results of 3D modelling of the flow structure in the classical symbiotic system Z~Andromedae are presented. Outbursts in systems of this type occur when the accretion rate exceeds the upper limit...
Angular dependence of direct rf power absorption studies in Bi2Sr2CaCu2O8 single crystals (2005)
Chockalingam, S. P., Sarangi, S., Bhat, S. V., Oka, K., Nishihara, Y.
We have studied rf power dissipation in Bi2Sr2CaCu2O8 single crystals as a function of angle between the applied field and c-axis of the crystal by using a novel technique of measuring direct rf...
Laser ARPES, the sudden approximation, and quasiparticle-like peaks in Bi2Sr2CaCu2O8+delta (2005)
Koralek, J. D., Douglas, J. F., Plumb, N. C., Sun, Z., Fedorov, A., Murnane, M., ...
A new low photon energy regime of angle resolved photoemission spectroscopy is accessed with lasers and used to study the superconductor Bi2Sr2CaCu2O8+delta. The low energy increases bulk...
Chockalingam, S. P., Sarangi, S., Bhat, S. V., Oka, K., Nishihara, Y.
Using a novel technique of measuring direct rf power dissipation, the temperature and magnetic field dependence of rf absorption in superconducting single crystals of Bi_2Sr_2CaCu_2O_8 is studied. An...
Chockalingam, SP, Sarangi, S, Bhat, SV, Oka, K, Nishihara, Y
We have studied rf power dissipation in $Bi_{2}Sr_{2}CaCu_{2}O_{8}$ single crystals as a function of angle \Theta between the applied field and c-axis of the crystal by using a novel technique of...
Chockalingam, SP, Sarangi, S, Bhat, SV, Oka, K, Nishihara, Y
We have studied rf power dissipation in $Bi_{2}Sr_{2}CaCu_{2}O_{8}$ single crystals as a function of angle \Theta between the applied field and c-axis of the crystal by using a novel technique of...
Matsuda, M., Kakurai, K., Kurogi, S., Kudo, K., Koike, Y., Yamaguchi, H., ...
Neutron scattering experiments were performed on the undoped and hole-doped Ca$_{2+x}$Y$_{2-x}$Cu$_5$O$_{10}$, which consists of ferromagnetic edge-sharing CuO$_2$ chains. It was previously reported...
Wind accretion in binary stars - I. Mass accretion ratio (2004)
Nagae, T., Oka, K., Matsuda, T., Fujiwara, H., Hachisu, I., Boffin, H. M. J.
Three-dimensional hydrodynamic calculations are performed in order to investigate mass transfer in a close binary system, in which one component undergoes mass loss through a wind. The mass ratio is...
Gas flow in close binary star systems (2004)
Oka, K., Matsuda, T., Hachisu, I., Boffin, H.
We first present a summary of our numerical work on accretion discs in close binary systems. Our recent studies on numerical simulations of the surface flow on the mass-losing star in a close binary...
Kadono, R., Higemoto, W., Koda, A., Larkin, M. I., Luke, G. M., Savici, A. T., ...
The vortex core radius \rv, defined as the peak position of the supercurrent around the vortex, has been determined by muon spin rotation measurements in the mixed state of \lscox for $x=0.13$, 0.15,...
Structure of end states for a Haldane Spin Chain (2002)
Kenzelmann, M., Xu, G., Zaliznyak, I. A., Broholm, C., DiTusa, J. F., Aeppli, G., ...
Inelastic neutron scattering was used to probe edge states in a quantum spin liquid. The experiment was performed on finite length antiferromagnetic spin-1 chains in Y_2BaNi_{1-x}Mg_xO_5. At finite...
Gromko, A. D., Fedorov, A. V., Aiura, Y., Yamaguchi, Y., Oka, K., ...
A well-known peak-dip-hump structure exists near $(\pi, 0)$ in superconducting state ARPES spectra of $Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta}$ (Bi2212). Here we report results on optimal and overdoped...
Gromko, A. D., Fedorov, A. V., Koralek, J. D., Aiura, Y., Yamaguchi, Y., ...
Using high-resolution angle-resolved photoemission spectroscopy on $Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta}$, we have made the first observation of a mass renormalization or "kink" in the E vs. $\vec k$...
Hu, Z., Knupfer, M., Kielwein, M., Rossler, U., Golden, M.S., Fink, J., ...
Gromko, A. D., Fedorov, A. V., Aiura, Y., Oka, K., Ando, Yoichi, ...
Using high energy resolution angle resolved photoemission spectroscopy, we have resolved the bilayer splitting effect in a wide range of dopings of the bilayer cuprate...
Optical conductivity of the nonsuperconducting cuprate La(8-x)Sr(x)Cu(8)O(20) (2001)
Lucarelli, A., Lupi, S., Calvani, P., Maselli, P., De Marzi, G., Roy, P., ...
La(8-x)Sr(x)Cu(8)O(20) is a non-superconducting cuprate, which exhibits a doubling of the elementary cell along the c axis. Its optical conductivity sigma (omega) has been first measured here, down...
Holes in a Quantum Spin Liquid (2001)
Xu, Guangyong, Aeppli, G., Bisher, M. E., Broholm, C., DiTusa, J. F., Frost, C. D., ...
Magnetic neutron scattering provides evidence for nucleation of antiferromagnetic droplets around impurities in a doped nickel-oxide based quantum magnet. The undoped parent compound contains a spin...
Gromko, A. D., Fedorov, A., Dessau, D. S., Aiura, Y., Oka, K., ...
We present high resolution ARPES data of the bilayer superconductor Bi2Sr2CaCu2O8 (Bi2212) showing a clear doubling of the near EF bands. This splitting approaches zero along the (0,0)-(pi,pi) nodal...
Holes in a quantum spin liquid (2000)
Xu, G, Aeppli, G, Bischer, P, Broholm, C, DiTusa, J F, Frost, C D, ...
Lamination of the masticatory muscles in the kangaroo according to their innervation (2000)
Nakajimq, K., Townsend, Grant Clement, Tomo, Soichiro, Ide, Y., Oka, K., Wakatsuki, E.
Lamination of the masticatory muscles in the kangaroo according to their innervation (2000)
Nakajimq, K., Townsend, Grant Clement, Tomo, Soichiro, Ide, Y., Oka, K., Wakatsuki, E.
Chuang, Y. D., Gromko, A. D., Dessau, D. S., Aiura, Y., Yamaguchi, Y., Oka, K., ...
We present a re-examination of the electronic structure and Fermi Surface (FS) of Bi-Sr-Ca-Cu-O (BSCCO) as obtained from angle-resolved photoemission experiments. By applying a stricter set of FS...
Sudershan, YS, Rastogi, Amit, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
The magnetic field dependent r.f. (20 MHz) power dissipation, P(H) vs H, for $H_{r.f.}$ \parallel c \parallel H in $Bi_2Sr_2CaCu_20_8$ (Bi 2 2 1 2) single crystals shows an onset at T \sim 102 K,...
Sudershan, YS, Rastogi, Amit, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the isothermal, magnetic field $(H\parallel c)$ dependent rf power P(H) dissipation $(H_{rf}\parallel a)$ in the superconducting state of $Bi_2Sr_2CaCu_2O_8$ single crystals prior to...
Sudershan, YS, Rastogi, Amit, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
The magnetic field dependent r.f. (20 MHz) power dissipation, P(H) vs H, for $H_{r.f.}$ \parallel c \parallel H in $Bi_2Sr_2CaCu_20_8$ (Bi 2 2 1 2) single crystals shows an onset at T \sim 102 K,...
Sudershan, YS, Rastogi, Amit, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the isothermal, magnetic field $(H\parallel c)$ dependent rf power P(H) dissipation $(H_{rf}\parallel a)$ in the superconducting state of $Bi_2Sr_2CaCu_2O_8$ single crystals prior to...
Oxygen displacement in a $^{107}Ag^{17+}$ ion irradiated $Bi_2Sr_2CaCu_2O_8$ single crystal (1997)
Sudershan, YS, Rastogi, Amit, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the magnetic field $(H\Vert c)$ dependent rf dissipation $(H_{rf}\Vert fa)$ in an as-grown $Bi_2Sr_2CaCu_2O_8$ single crystal prior to and after irradiation with 250 MeV...
Sudershan, YS, Amit, Rastogi, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the magnetic field dependent rf (20 MHz) losses in $Bi_2Sr_2CaCu_2O_8$ single crystals in the low field and high temperature regime. Above $H_C_l$ the dissipation begins to decrease...
Sudershan, YS, Amit, Rastogi, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the magnetic field dependent rf (20 MHz) losses in $Bi_2Sr_2CaCu_2O_8$ single crystals in the low field and high temperature regime. Above $H_C_l$ the dissipation begins to decrease...
Oxygen displacement in a $^{107}Ag^{17+}$ ion irradiated $Bi_2Sr_2CaCu_2O_8$ single crystal (1997)
Sudershan, YS, Rastogi, Amit, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the magnetic field $(H\Vert c)$ dependent rf dissipation $(H_{rf}\Vert fa)$ in an as-grown $Bi_2Sr_2CaCu_2O_8$ single crystal prior to and after irradiation with 250 MeV...
Rastogi, Amit, Sudershan, YS, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
The results of nonresonant microwave absorption (NRMA) studies in Bi2212 single crystals for the $H\Vert c$ axis and $H\Vert ab$ plane are reported. In the former orientation, over a few degrees...
Rastogi, Amit, Sudershan, YS, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
The results of nonresonant microwave absorption (NRMA) studies in Bi2212 single crystals for the $H\Vert c$ axis and $H\Vert ab$ plane are reported. In the former orientation, over a few degrees...
Heavy ion irradiation effects on magnetic field dependent rf losses in Bi2212 single crystals (1996)
Sudershan, YS, Rastogi, A, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the magnetic field dependent non-resonant rf losses in as-grown Bi2212 single crystals prior to and after irradiation with 250 MeV $^{107}Ag^{17+}$ ions. In the pristine state the...
Microwave response of vortex dynamics in Bi2212 single crystals (1996)
Rastogi, A, Sudershan, YS, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
The response of the vortices in a dynamic state is studied in single crystals of Bi2212 using the technique of non-resonant microwave absorption (NRMA). It is observed that with the magnetic field...
Heavy ion irradiation effects on magnetic field dependent rf losses in Bi2212 single crystals (1996)
Sudershan, YS, Rastogi, A, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
We have studied the magnetic field dependent non-resonant rf losses in as-grown Bi2212 single crystals prior to and after irradiation with 250 MeV $^{107}Ag^{17+}$ ions. In the pristine state the...
Microwave response of vortex dynamics in Bi2212 single crystals (1996)
Rastogi, A, Sudershan, YS, Bhat, SV, Grover, AK, Yamaguchi, Y, Oka, K, ...
The response of the vortices in a dynamic state is studied in single crystals of Bi2212 using the technique of non-resonant microwave absorption (NRMA). It is observed that with the magnetic field...
RAMAN STUDY OF La2-xBaxCuO4 (x= 0, 0.016) SINGLE CRYSTALS (1988)
Koshizuka, N., Unoki, H., Oka, K., Hayashi, K., Okuda, T., Kimura, Y.
Raman scattering of La2-xBaxCuO4 (x = 0, 0.016) single crystals has been measured at various temperatures in the frequency range between 100 and 5000 cm-1. Besides an A1g phonon line at 430 cm-1, the...
RAMAN STUDY OF La2-xBaxCuO4 (x= 0, 0.016) SINGLE CRYSTALS (1988)
Koshizuka, N., Unoki, H., Oka, K., Hayashi, K., Okuda, T., Kimura, Y.
Raman scattering of La2-xBaxCuO4 (x = 0, 0.016) single crystals has been measured at various temperatures in the frequency range between 100 and 5000 cm-1. Besides an A1g phonon line at 430 cm-1, the...
RAMAN STUDY OF La2-xBaxCuO4 (x= 0, 0.016) SINGLE CRYSTALS (1988)
Koshizuka, N., Unoki, H., Oka, K., Hayashi, K., Okuda, T., Kimura, Y.
Raman scattering of La2-xBaxCuO4 (x = 0, 0.016) single crystals has been measured at various temperatures in the frequency range between 100 and 5000 cm-1. Besides an A1g phonon line at 430 cm-1, the...
Internal Ca2+ mobilization is altered in fibroblasts from patients with Alzheimer disease.
Ito, E, Oka, K, Etcheberrigaray, R, Nelson, T J, McPhie, D L, Tofel-Grehl, B, ...
The recent demonstration of K+ channel dysfunction in fibroblasts from Alzheimer disease (AD) patients and past observations of Ca(2+)-mediated K+ channel modulation during memory storage suggested...
Potassium channel dysfunction in fibroblasts identifies patients with Alzheimer disease.
Etcheberrigaray, R, Ito, E, Oka, K, Tofel-Grehl, B, Gibson, G E, Alkon, D L
Since memory loss is characteristic of Alzheimer disease (AD), and since K+ channels change during acquisition of memory in both molluscs and mammals, we investigated K+ channel function as a...
Long-term transformation of an inhibitory into an excitatory GABAergic synaptic response.
Alkon, D L, Sánchez-Andrés, J V, Ito, E, Oka, K, Yoshioka, T, Collin, C
For a constant membrane potential, a predominantly inhibitory GABAergic synaptic response is shown to undergo long-term transformation into an excitatory response after pairing of exogenous...
Tokunaga, T, Oka, K, Takemoto, A, Ohtsubo, Y, Gotoh, N, Nishino, T
The antimicrobial activity of trimethoprim is antagonized by thymidine in in vitro susceptibility tests. The purpose of this investigation was to determine whether this antagonism also occurred...
Determination of pipemidic acid in plasma by normal-phase high-pressure liquid chromatography.
Ito, H, Inoue, M, Morikawa, M, Tsuboi, M, Oka, K
An improved high-pressure liquid chromatography procedure for determining the concentration of pipemidic acid in human plasma was developed, which uses a normal-phase silica gel column and aqueous...
Molecular cloning and sequence of a cDNA coding for bovine lipoprotein lipase.
Senda, M, Oka, K, Brown, W V, Qasba, P K, Furuichi, Y
Lipoprotein lipase (LPL; triacylglycero-protein acylhydrolase, EC 3.1.1.34) was purified from bovine milk. Synthetic oligonucleotides were prepared, based on the amino acid sequences of three...
Presence and formation of codeine and morphine in the rat.
Donnerer, J, Oka, K, Brossi, A, Rice, K C, Spector, S
Endogenous codeine and morphine were identified in rat brain by immunological determination following HPLC. To demonstrate occurrence of a biosynthetic pathway to morphine in mammals similar to that...
Isolation of morphine from toad skin.
Oka, K, Kantrowitz, J D, Spector, S
A nonpeptide opioid was found in toad skin and purified to homogeneity by using HPLC with electrochemical detection. A nonpeptide opioid also was detected in bovine brain and adrenals as well as...
Jong, M C, Van Dijk, K W, Dahlmans, V E, Kobayashi, K, Oka, K, ...
We have shown previously that human apolipoprotein (apo)C1 transgenic mice exhibit hyperlipidaemia, due primarily to an impaired clearance of very-low-density lipoprotein (VLDL) particles from the...
Ishimura-Oka, K, Faustinella, F, Kihara, S, Smith, L C, Oka, K, Chan, L
We have investigated a patient of English ancestry with familial chylomicronemia caused by lipoprotein lipase (LPL) deficiency. DNA sequence analysis of all exons and intron-exon boundaries of the...
Internal Ca2+ mobilization is altered in fibroblasts from patients with Alzheimer disease.
Ito, E, Oka, K, Etcheberrigaray, R, Nelson, T J, McPhie, D L, Tofel-Grehl, B, ...
The recent demonstration of K+ channel dysfunction in fibroblasts from Alzheimer disease (AD) patients and past observations of Ca(2+)-mediated K+ channel modulation during memory storage suggested...
Potassium channel dysfunction in fibroblasts identifies patients with Alzheimer disease.
Etcheberrigaray, R, Ito, E, Oka, K, Tofel-Grehl, B, Gibson, G E, Alkon, D L
Since memory loss is characteristic of Alzheimer disease (AD), and since K+ channels change during acquisition of memory in both molluscs and mammals, we investigated K+ channel function as a...
Long-term transformation of an inhibitory into an excitatory GABAergic synaptic response.
Alkon, D L, Sánchez-Andrés, J V, Ito, E, Oka, K, Yoshioka, T, Collin, C
For a constant membrane potential, a predominantly inhibitory GABAergic synaptic response is shown to undergo long-term transformation into an excitatory response after pairing of exogenous...
Tokunaga, T, Oka, K, Takemoto, A, Ohtsubo, Y, Gotoh, N, Nishino, T
The antimicrobial activity of trimethoprim is antagonized by thymidine in in vitro susceptibility tests. The purpose of this investigation was to determine whether this antagonism also occurred...