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ABSTRACT: Spin-flip M1 strengths in Pb208 have been measured in photon scattering experiments with a quasi-monochromatic, linearly polarized photon beam. The data resolve an M1 giant resonance into at least seven, possibly eight, discrete transitions at excitation energies between 7.1 and 7.4 MeV below the neutron separation energy. The M1 strengths are measured with uncertainties considerably smaller than those in a previous study, which leads to a reexamination of the total strength. Experimental results are compared with an estimation of self-consistent random phase approximation using a semirealistic interaction.
Physical Review C - PHYS REV C. 01/2008; 78(6).
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ABSTRACT: Neutron activation analysis with multi-parameter coincidence method was developed at the Japan Atomic Energy Agency (JAEA)
and a non-destructive, ultra-high sensitive multi-elemental determination has been realized. The multi-parameter coincidence
method is carried out with an array of 19 germanium detectors, GEMINI-II. Using this system, very weak γ-rays emitted from
trace amounts of elements can be detected. The presolar grains were extracted from the Allende meteorite. Trace elements in
the presolar diamonds were measured by neutron activation analysis with multi-parameter coincidence method.
Journal of Radioanalytical and Nuclear Chemistry - J RADIOANAL NUCL CHEM. 01/2008; 276(1):213-216.
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T. Kishimoto, T. Hayakawa,
S. Ajimura,
F. Khanam, T. Itabashi, K. Matsuoka, S. Minami,
Y. Mitoma,
A. Sakaguchi, Y. Shimizu,
K. Terai,
R. E. Chrien
Progress of Theoretical Physics Supplement - PROG THEOR PHYS SUPPL. 01/2007; 168:573-580.
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ABSTRACT: Excited states in neutron-rich 187W have been populated via deep inelastic collisions of a 630-MeV 82Se beam on a 186W target. Projectilelike fragments were measured by an annular Si detector for reaction channel selection. Delayed gamma rays from target residues were detected by means of the so-called recoil shadow technique. A new isomer at 411 keV, based on the 11/2+[615] Nilsson configuration, has been identified with a half-life of 1.55(13) mus. The decay rates of the isomers are discussed in terms of the K quantum number by comparison with the systematics from neighboring nuclei.
Physical Review C - PHYS REV C. 01/2005; 71(6).
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ABSTRACT: Cross sections of the 186W, 187Re, 188Os(gamma,n) reactions were measured using quasi monochromatic gamma-ray beams from laser Compton scattering (LCS), and results for the latter reaction are presented here. Neutron capture cross sections of the inverse reactions were evaluated by the Hauser-Feshbach statistical calculation where the experimental data were used to constrain the model parameters, especially the E1 strength function. The influence of the neutron capture by the 9.75 keV first excited state in 187Os which is substantially populated in stellar plasmas at typical s-process temperatures is examined in connection with the 187Re-187Os cosmochronology.
Nuclear Physics A - NUCL PHYS A. 01/2005; 758:561-564.
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C. Y. Xie,
X. H. Zhou,
Y. Zheng,
Y. H. Zhang,
Z. Liu,
Z. G. Gan, T. Hayakawa,
M. Oshima,
T. Toh,
T. Shizuma,
J. Katakura,
Y. Hatsukawa
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ABSTRACT: The level structure of the doubly odd nucleus 146Tb has been studied via the 118Sn( 32S, 1p3n) reaction using techniques of in-beam $\gamma $ -ray spectroscopy. Measurements of $\gamma $ -ray anisotropies, X- $\gamma $ and $\gamma $ - $\gamma $ -t coincidences were performed with 12 BGO(AC)HPGe detectors. Based on the measured results, the level scheme of 146Tb has been revised significantly and extended up to an excitation energy of 8.39 MeV. The level structure has been interpreted qualitatively by coupling an h 11/2 proton-particle and an h 11/2 neutron-hole to the excited states in the 146Gd core.
European Physical Journal A - EUR PHYS J A. 01/2004; 19(1):7-9.
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H. Utsunomiya,
K. Y. Hara,
S. Goko,
H. Akimune,
T. Yamagata,
M. Ohta,
H. Ohgaki,
H. Toyokawa, T. Hayakawa,
T. Shizuma,
P. Mohr,
Y.-W. Lui
Nuclear Physics A - NUCL PHYS A. 01/2004; 738:136-142.
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M. Koizumi,
A. Seki,
Y. Toh,
A. Osa,
Y. Utsuno,
A. Kimura,
M. Oshima, T. Hayakawa,
Y. Hatsukawa,
J. Katakura,
M. Matsuda,
T. Shizuma
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ABSTRACT: Coulomb excitation experiment was carried out with a 68Zn beam bombarding a natPb target. Two E2 matrix elements and the quadrupole moment of the 21+ state were newly derived with the least-squares search code GOSIA. The potential energy surface (PES) was calculated with the Nilsson–Strutinsky model, showing two shallow minima: the first minimum does not contain the 1g9/2 orbit below the Fermi surface, while the second minimum does. The ground state band and the intruder band seem to be constructed on the first and the second minimum, respectively. As for the ground state band, the asymmetric rotor model and the IBM in O(6) limit reproduced the experimental values rather well. The shallow PES may suggest instability of the shape. The ground state band structure may be explained assuming a soft triaxial deformation.
Nuclear Physics A - NUCL PHYS A. 01/2004; 730(1):46-58.
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Wang Shou-Yu,
Ma Ying-Jun,
T. Komatsubara,
Liu Yun-Zuo,
Zhang Yu-Hu,
K. Furuno, T. Hayakawa,
J. Mukai,
Y. Iwata,
T. Morikawa,
G. B. Hagemann,
G. Sletten
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ABSTRACT: High spin states of the odd proton nucleus 123I have been populated in the reaction 116Cd(14N, 5n2p) at a beam energy of 65 MeV. Two previously known positive-parity ΔI = 2 sequences have been extended up to 31/2+ and 41/2+. In addition, a number of ΔI = 1 transitions linking the two ΔI = 2 sequences have been observed. It is suggested that both the ΔI = 2 sequences are built upon the oblate πg7/2[404]7/2+ Nilsson configuration.
Chinese Physics Letters - CHIN PHYS LETT. 01/2004; 21(6):1024-1026.
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M. Ukai,
S. Ajimura,
H. Akikawa,
D. Alburger, A. Banu,
R. Chrien,
G. Franklin,
J. Franz, O. Hashimoto, T. Hayakawa,
H. Hotchi,
K. Imai
Physical Review Letters - PHYS REV LETT. 01/2004; 93(23).
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T. Hayakawa, Y. Toh, M. Oshima,
M. Matsuda,
Y. Hatsukawa,
T. Shizuma,
J. Katakura,
H. Iimura, S. Mitarai,
Y. Zhang, M. Sugawara,
H. Kusakari
Physical Review C - PHYS REV C. 01/2003; 68(6).
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ABSTRACT: : Excited states in 187Re populated by inelastic scattering of a 500 MeV 82Se beam have been studied by means of in-beam γ-ray spectroscopy. Levels built on the 5/2+[402] and 9/2-[514] one-quasiparticle states were measured up to I
π = (21/2+) and (21/2-), respectively. In addition, several new levels including an isomer at 1682 keV with a half-life of 114(23) ns have been
found. Quasiparticle configurations of the levels and the transition rates are discussed.
European Physical Journal A - EUR PHYS J A. 01/2003; 17(2):159-165.
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ABSTRACT: High-spin states in 180Ir have been investigated by means of in-beam gamma-ray spectroscopy techniques with the 154Sm(31P,5ngamma)180Ir reaction. Excitation functions, x-gamma and gamma-gamma-t coincidences, DCO (directional correlation of gamma rays deexciting oriented states) ratios, and intraband B(M1)/B(E2) ratios were measured. Five rotational bands have been identified and their configurations are proposed on the basis of B(M1)/B(E2) ratios and by comparing the band properties with known bands in neighboring odd-mass and even-mass nuclei. The neutron AB crossing is observed at homegac=0.26(1) MeV for the pi1/2-[541]⊗nu1/2-[521] and pi1/2-[541]⊗nu5/2-[512] bands, respectively. Staggering of levels as a function of the number of neutron pairs is revealed in the pi1/2-[541]⊗nu1/2-[521] doubly decoupled bands of 178-186Ir. The gradual alignment gains at low rotational frequencies are observed in the two strongly coupled bands. Band crossings and alignments in 180Ir are discussed with reference to the total Routhian surface and cranked shell model calculations performed for the neighboring odd-mass nuclei.
Physical Review C - PHYS REV C. 01/2002; 65(1).
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ABSTRACT: We previously demonstrated that high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) equipped with a graphitized carbon column (GCC) is useful for the structural analysis of carbohydrates in glycoproteins. Using LC/MS with GCC, sulfated N-linked oligosaccharides were found in erythropoietin (EPO) expressed in baby hamster kidney cells. Sulfation occurs in a part of the N-linked oligosaccharides in the EPO. Sulfated monosaccharide residue in the sulfated N-linked oligosaccharide was determined by exoglycosidase digestion followed by sugar mapping by LC/MS. The linkage position and branch-location of the sulfate group in the tetraantennary oligosaccharide were analyzed by (1)H-nuclear magnetic resonance. It was suggested that sulfation occurs on the C-6 position of GlcNAc located in the GlcNAcbeta1-4Manalpha1-3 branch.
Glycobiology 01/2002; 11(12):1043-9. · 3.58 Impact Factor
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ABSTRACT: We previously reported that ganglioside GD1a, which is highly expressed in poorly metastatic FBJ-S1 cells, inhibits the serum-induced motility of FBJ-LL cells and that the metastatic potential of FBJ-LL cells is completely suppressed by enforced GD1a expression (Hyuga et al., Int J Cancer 1999;83:685-91). We recently discovered that hepatocyte growth factor (HGF) induces FBJ-LL cell motility. In the present study, the HGF-induced motility of FBJ-S1 cells was found to be one-thirtieth that of FBJ-LL cells. This motility of GD1a-expressing transfectants, which were produced by transfection of FBJ-LL cells with GM2/GD2 synthase cDNA, decreased with increases in their GD1a expression and HGF induced almost no motility in GD1a-pretreated FBJ-LL cells, indicating that GD1a inhibits the HGF-induced motility of FBJ-LL cells. The expression of the HGF receptor c-Met on FBJ-S1 cells, FBJ-LL cells, transfectants and a mock-transfectant was almost the same. The level of tyrosine phosphorylation of c-Met after HGF stimulation in FBJ-S1 cells, GD1a-pretreated FBJ-LL cells and a GD1a-expressing transfectant was significantly lower than in FBJ-LL cells and a mock-transfectant. These findings suggested that GD1a inhibits the HGF-induced motility of FBJ-LL cells through suppression of tyrosine phosphorylation of c-Met. HepG2 cells, a human hepatoma cell line, were used to investigate whether GD1a interferes with other cancer cells expressing c-Met. HepG2 cells did not express GD1a. HGF induced cell scattering of HepG2 cells and the scattering was inhibited by pretreating the cells with GD1a. The c-Met in the cells was autophosphorylated by stimulation with HGF, but after treating the cells with GD1a, the HGF-induced autophosphorylation of c-Met was suppressed. These results suggest that GD1a acts as a negative regulator of c-Met in cancer cells.
International Journal of Cancer 12/2001; 94(3):328-34. · 5.44 Impact Factor
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ABSTRACT: Selective glycopeptide mapping of recombinant human erythropoietin (rhEPO) used as a model glycoprotein was successfully carried out by on-line high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) using a Vydac C18 column eluted in acetonitrile-1 mM ammonium acetate, pH 6.8. rhEPO expressed in a Chinese hamster ovary clone was exhaustively digested into four glycopeptides and nine peptides with endoproteinase Glu-C. Both glycopeptides and peptides were eluted with trifluoroacetic acid as the eluent, whereas only glycopeptides were eluted selectively with ammonium acetate in the following order: N38, N24, 0126, and N83. Furthermore, many glycoforms included in each glycopeptide were found to be separated by differences in the numbers of sialic acid and N-acetyllactosaminyl repeats. Twenty, 16 and 22 different N-linked oligosaccharides were determined at Asn24, 38, and 83, respectively, and two different O-linked oligosaccharides were observed at Ser126. Our method is simple, rapid, and useful for determining the carbohydrate structures at each glycosylation site and for elucidating the site-specific carbohydrate heterogeneity.
Journal of Chromatography 03/2001; 910(1):1-11. · 4.53 Impact Factor
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ABSTRACT: We reported previously that peptide mapping using high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) and liquid chromatography with tandem mass spectrometry (LC/MS/MS) are useful for determination of the glycosylation sites, carbohydrate structure, and site-specific carbohydrate heterogeneity of glycoproteins. Here, with intention to enhance the sensitivity and shorten the time-span of analysis to characterize glycoproteins, especially biotechnological products with carbohydrate moieties, we studied the introduction of HPLC with a microbore column to LC/MS with recombinant erythropoietin (rh-EPO). In addition, we evaluated the ability of LC/MS/MS precursor-ion scanning to make identification of glycopeptides and facilitate the analysis of carbohydrate moieties. We found that the peptide mapping with microbore HPLC is highly sensitive and more rapid than the previous method, and the precursor-ion scanning is helpful for identifying glycopeptides. Our results indicate that these methods are very useful for characterization and quality control of the carbohydrate moieties of biotechnological products.
Kokuritsu Iyakuhin Shokuhin Eisei Kenkyūjo hōkoku = Bulletin of National Institute of Health Sciences 02/2001;
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ABSTRACT: A simple, rapid, and accurate assay using surface plasmon resonance (SPR) apparatus with anti-follistatin antibody (SPR immunoassay) has been developed for the quantitation of recombinant follistatin. This assay can be performed with a direct injection of conditioned medium; results were obtained within 10 min. The quantitation component of this assay was precise and accurate with a limit of quantitation of 62.5 ng/ml in Ham's F12 medium containing 2% fetal bovine serum. These results demonstrate that SPR immunoassay is a powerful technique for several researches, especially for screening of gene transfectant and monitoring of protein production.
Kokuritsu Iyakuhin Shokuhin Eisei Kenkyūjo hōkoku = Bulletin of National Institute of Health Sciences 02/2001;
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ABSTRACT: High-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) and liquid chromatography with tandem mass spectrometry (LC/MS/MS) were applied to the analysis of the site-specific carbohydrate heterogeneity in erythropoietin (EPO) used as a model of the sialylated glycoprotein. N-linked oligosaccharides were released from recombinant human EPO expressed in Chinese hamster ovary cells enzymatically and reduced with NaBH(4). Many different sialylated oligosaccharides of EPO were separated and characterized by LC/MS equipped with a graphitized carbon column (GCC). Glycosylation sites and the preliminary glycosylation pattern at each glycosylation site were determined by LC/MS of endoproteinase Glu-C-digested EPO. The detailed site-specific carbohydrate heterogeneity caused by the differences in the molecular weight, branch, linkage, and sequence was elucidated by GCC-LC/MS of the N-linked oligosaccharides released from the isolated glycopeptides. Structural details of the isomers were analyzed by LC/MS/MS, and it was indicated that di- and trisialylated tetraantennary oligosaccharides are attached to Asn24, 38, and 83, whereas their isomers, di- and trisialylated triantennary oligosaccharides containing N-acetyllactosamines, are combined with Asn24. Our method is useful for the determination of glycosylation sites, the site-specific carbohydrate heterogeneity of glycoproteins, and the carbohydrate structure.
Analytical Biochemistry 11/2000; 285(1):82-91. · 3.00 Impact Factor
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ABSTRACT: The molecular mechanism of organ-specific metastasis to the liver remains largely unknown. However, it is conceivable that paracrine growth factors produced by a target organ induce migration and proliferation of malignant cells to that organ, and this is the cause of organ-specific metastasis. In this study, we investigated the effect of hepatocyte growth factor/scatter factor (HGF/SF) and activin A, which are known to be produced by the liver, on the motility and growth of liver-metastatic cell line FBJ-LL. HGF/SF and activin A induced motility synergistically, but they did not affect the proliferation of FBJ-LL cells. Expression of the HGF/SF receptor, the c-met gene, and the activin-receptor type IA, type IB, and type IIA genes in FBJ-LL cells was detected by reverse transcription polymerase chain reaction. These findings suggest that both HGF/SF and activin A promote organ-specific metastasis to the liver by induction of migration through their specific receptors on liver-metastatic cells.
Cancer Letters 06/2000; 153(1-2):137-43. · 4.24 Impact Factor
