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540 results on '"Takimoto M"'

1. Energy of the $^{229}$Th Nuclear Clock Isomer Determined by Absolute $\gamma$-ray Energy Difference

Author

Yamaguchi, A., Muramatsu, H., Hayashi, T., Yuasa, N., Nakamura, K., Takimoto, M., Haba, H., Konashi, K., Watanabe, M., Kikunaga, H., Maehata, K., Yamasaki, N. Y., and Mitsuda, K.

Subjects
Nuclear Experiment, Physics - Atomic Physics
Abstract

The low-lying isomeric state of $^{229}$Th provides unique opportunities for high-resolution laser spectroscopy of the atomic nucleus. We determine the energy of this isomeric state by taking the absolute energy difference between the excitation energy required to populate the 29.2-keV state from the ground-state and the energy emitted in its decay to the isomeric excited state. A transition-edge sensor microcalorimeter was used to measure the absolute energy of the 29.2-keV $\gamma$-ray. Together with the cross-band transition energy (29.2 keV$\to$ground) and the branching ratio of the 29.2-keV state measured in a recent study, the isomer energy was determined to be 8.30$\pm$0.92 eV. Our result is in agreement with latest measurements based on different experimental techniques, which further confirms that the isomeric state of $^{229}$Th is in the laser-accessible vacuum ultraviolet range., Comment: 6 pages, 4 figures, 2 tables

Published
2019
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3. $\alpha$ cluster states in $^{44, 46, 52}$Ti

Author

Fukada, M., Takimoto, M. K., Ogino, K., and Ohkubo, S.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

$\alpha$ decaying states of $^{44, 46, 52}$Ti were investigated with angular correlation functions between $t$ and $\alpha$ with the $^{40, 42, 48}$Ca($^7$Li, $t\alpha$)$^{40, 42, 48}$Ca reactions at E = 26.0 MeV. Many $\alpha$ cluster states were newly observed in the 10 - 15 MeV excitation energy of $^{44}$Ti and their spin-parities were assigned, in which $J^\pi=7^-$ state was found at 11.95 MeV as a candidate for the member of the $K=0_1^-$ negative parity band. In $^{46}$Ti many $\alpha$ cluster states were also found in the 11 - 17 MeV excitation energy with the $^{42}$Ca($^7$Li, $t\alpha$)$^{42}$Ca reaction, though its strength is weak compared to $^{44}$Ti. No $\alpha$ cluster states were detected for the $^{48}$Ca($^7$Li, $t\alpha$)$^{48}$Ca reaction, in which the number of coincidence events decaying from $^{48}$Ca was very small.

Published
2011
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4. Metal-insulator transition in PrRu$_4$P$_{12}$ and SmRu$_4$P$_{12}$ investigated by optical spectroscopy

Author

Matsunami, M., Chen, L., Takimoto, M., Okamura, H., Nanba, T., Sekine, C., and Shirotani, I.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Electronic structures of the filled-skutterudite compounds PrRu$_4$P$_{12}$ and SmRu$_4$P$_{12}$, which undergo a metal-insulator transition (MIT) at $T_{\rm MI}$ = 60 K and 16 K, respectively, have been studied by means of optical spectroscopy. Their optical conductivity spectra develop an energy gap of $\sim$ 10 meV below $T_{\rm MI}$. The observed characteristics of the energy gap are qualitatively different from those of the Kondo semiconductors. In addition, optical phonon peaks in the spectra show anomalies upon the MIT, including broadening and shifts at $T_{\rm MI}$ and an appearance of new peaks below $T_{\rm MI}$. These results are discussed in terms of density waves or orbital ordering previously predicted for these compounds., Comment: 4pages, 4figures, submitted to Physical Review B

Published
2005
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19. Multifactorial Regulation of the Human c-myc Oncogene

Author

Zajac-Kaye, M., Avigan, M., Takimoto, M., Pittaluga, S., Quinn, J., Gelmann, E., Levens, D., Compans, R. W., editor, Cooper, M., editor, Koprowski, H., editor, McConell, I., editor, Melchers, F., editor, Oldstone, M., editor, Olsnes, S., editor, Saedler, H., editor, Vogt, P. K., editor, Wagner, H., editor, Wilson, I., editor, Potter, Michael, editor, and Melchers, Fritz, editor

Published
1988
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21. Suppression of metastatic cancer by N116Y

Author

Takeuchi, M., Shichinohe, T., Senmaru, N., Miyamoto, M., Fujita, H., Takimoto, M., Kondo, S., Katoh, H., and Kuzumaki, N.

Subjects
liver metastasis, ras suppressor, pancreatic cancer, 491.69
Abstract

In pancreatic cancer, the mutation of c-K-ras is a critical event of tumor growth and metastasis.1 We have previously demonstrated a dominant negative effect of N116Y on the growth of pancreatic cancer cells.2 To evaluate the potential of N116Y for suppressing the metastatic growth of pancreatic tumor cells, we made a replication-deficient recombinant N116Y adenovirus driven by the carcinoembryonic antigen (CEA) promoter (Ad CEA-N116Y). We demonstrated that the expression of N116Y, growth inhibition, and apoptotic death induction were all specific to pancreatic cancer cell lines (PCI-35 and PCI-43) that were promoter positive, whereas no growth retardation was observed in human embryonic pancreas-derived cell line 1C3D3 after Ad CEA-N116Y infection. We examined the effect of Ad CEA-N116Y on the metastatic growth of PCI-43 colonies in liver, which were generated by tumor injection into the spleen of nude mice. The results showed that Ad CEA-N116Y effectively reduced the number of metastatic colonies without any complication by injecting intrasplenically five days after tumor cell inoculation. Thus N116Y can selectively suppress the metastatic growth of pancreatic tumor cell by using the CEA promoter driven adenovirus vector indicating that N116Y gene therapy may be potentially useful for the treatment of pancreatic cancer patients with liver micrometastasis.

Published
2000

27. A case of low-grade fibromyxoid sarcoma

Author

Ebara H, Takimoto M, Matsuda M, Takaba E, Katsura T, Kataoka Y, Yoshida F, and Tanaka K

Subjects
Aged, 80 and over, Pathology, medicine.medical_specialty, business.industry, Abdominal Neoplasms, Fibrosarcoma, medicine, Humans, General Medicine, medicine.disease, business, Aged, Low-grade fibromyxoid sarcoma
Published
1997

31. A new method for measuring dynamic change of tracer distribution using dynamic single photon emission tomography with a slip-ring rotational gamma camera

Author

Yoshiharu Miyazaki, Katsuhito Yoshioka, Shiozaki J, Murata Y, Inoue H, Kenichi Nakajima, Seigo Kinuya, Junichi Taki, Hashimoto M, and Takimoto M

Subjects
Male, Quality Control, Materials science, Rotation, Imaging phantom, Slip ring, law.invention, Time frame, Nuclear magnetic resonance, law, TRACER, Single Photon Emission Tomography, Humans, Radiology, Nuclear Medicine and imaging, Gamma Cameras, Cysteine, Gamma camera, Aged, Tomography, Emission-Computed, Single-Photon, business.industry, Phantoms, Imaging, Brain, General Medicine, Organotechnetium Compounds, Middle Aged, Pharmacokinetic analysis, Acetazolamide, Cerebrovascular Disorders, Distribution (mathematics), Feasibility Studies, Female, Radiopharmaceuticals, Nuclear medicine, business, Meningioma
Abstract

The clinical applicability of dynamic single photon emission tomograpy (SPET) using a dual-head gamma camera equipped with a slip-ring rotational mechanism, referred to as serial SPET, was examined in the present investigation. Serial SPET enables the production of tomographic images for any arbitrary time frame from an arbitrary range of data to 360°. In a pre-clinical evaluation, a correlation between radioactivity concentration and serial SPET counts was evaluated in a phantom with continuous changes in 99m Tc concentration. A differential value was obtained from each pair of SPET images; moreover, moving average approximation processing was investigated with respect to the elimination of noise in the data. In 11 and one patient presenting with cerebrovascular disease and meningioma, respectively, changes in SPET counts were evaluated when 99m Tc ethyl cysteinate dimer ( 99m Tc-ECD) was continuously administered at a constant rate in the resting state. Furthermore, in six of 11 subjects with cerebrovascular disease, changes occurring in SPET counts were examined by using acetazolamide loading while continuously administering 99m Tc-ECD at a constant rate. Consequently, serial SPET enabled the evaluation of changes in radioactivity concentration over time in both the phantom and preliminary clinical studies. Data analysis by differential processing utilizing moving average approximation processing enabled the detection of minor changes in radioactivity concentration. An increase of 15.1±5.4% was observed in SPET counts of the unaffected cerebral hemisphere with acetazolamide loading. The response of the affected hemisphere was less prominent. These findings suggest that serial SPET would be an effective technique for the pharmacokinetic analysis of radiopharmaceuticals in vivo.

Published
2002

45. BRAF mutations and phosphorylation status of mitogen-activated protein kinases in the development of flat and depressed-type colorectal neoplasias

Author

Konishi, K, primary, Takimoto, M, additional, Kaneko, K, additional, Makino, R, additional, Hirayama, Y, additional, Nozawa, H, additional, Kurahashi, T, additional, Kumekawa, Y, additional, Yamamoto, T, additional, Ito, H, additional, Yoshikawa, N, additional, Kusano, M, additional, Nakayama, K, additional, Rembacken, B J, additional, Ota, H, additional, and Imawari, M, additional

Published
2005
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