438 results on '"F, Matsubara"'
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2. The best defense is a good defense: adapting negotiation methods for tackling pressure over software project estimates.
- Author
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Patrícia G. F. Matsubara, Igor Steinmacher, Bruno Gadelha, and Tayana Conte
- Published
- 2022
- Full Text
- View/download PDF
3. Buying time in software development: how estimates become commitments?
- Author
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Patrícia G. F. Matsubara, Igor Steinmacher, Bruno Gadelha, and Tayana Uchôa Conte
- Published
- 2021
- Full Text
- View/download PDF
4. Much more than a prediction: Expert-based software effort estimation as a behavioral act.
- Author
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Patrícia G. F. Matsubara, Igor Steinmacher, Bruno Gadelha, and Tayana Conte
- Published
- 2023
- Full Text
- View/download PDF
5. Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: a multi-biomarker reconstruction from Paru Co
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A. Callegaro, D. Battistel, N. M. Kehrwald, F. Matsubara Pereira, T. Kirchgeorg, M. D. C. Villoslada Hidalgo, B. W. Bird, and C. Barbante
- Subjects
Environmental pollution ,TD172-193.5 ,Environmental protection ,TD169-171.8 ,Environmental sciences ,GE1-350 - Abstract
The fire history of the Tibetan Plateau over centennial to millennial timescales is not well known. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, can provide continuous records of local environmental change on millennial scales during the Holocene through the accumulation and preservation of specific organic molecular biomarkers. To reconstruct Holocene fire events and vegetation changes occurring on the southeastern Tibetan Plateau and the surrounding areas, we used a multi-proxy approach, investigating multiple biomarkers preserved in core sediment samples retrieved from Paru Co, a small lake located in the Nyainqentanglha Mountains (29°47′45.6′′ N, 92°21′07.2′′ E; 4845 m a.s.l.). Biomarkers include n-alkanes as indicators of vegetation, polycyclic aromatic hydrocarbons (PAHs) as combustion proxies, fecal sterols and stanols (FeSts) as indicators of the presence of humans or grazing animals, and finally monosaccharide anhydrides (MAs) as specific markers of vegetation burning processes. Insolation changes and the associated influence on the Indian summer monsoon (ISM) affect the vegetation distribution and fire types recorded in Paru Co throughout the Holocene. The early Holocene (10.7–7.5 cal kyr BP) n-alkane ratios demonstrate oscillations between grass and conifer communities, resulting in respective smouldering fires represented by levoglucosan peaks, and high-temperature fires represented by high-molecular-weight PAHs. Forest cover increases with a strengthened ISM, where coincident high levoglucosan to mannosan (L ∕ M) ratios are consistent with conifer burning. The decrease in the ISM at 4.2 cal kyr BP corresponds with the expansion of regional civilizations, although the lack of human FeSts above the method detection limits excludes local anthropogenic influence on fire and vegetation changes. The late Holocene is characterized by a relatively shallow lake surrounded by grassland, where all biomarkers other than PAHs display only minor variations. The sum of PAHs steadily increases throughout the late Holocene, suggesting a net increase in local to regional combustion that is separate from vegetation and climate change.
- Published
- 2018
- Full Text
- View/download PDF
6. Molecular‐Multiproxy Assessment of Land‐Derived Organic Matter Degradation Over Extensive Scales of the East Siberian Arctic Shelf Seas
- Author
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F. Matsubara, B. Wild, J. Martens, A. Andersson, R. Wennström, L. Bröder, O. V. Dudarev, I. Semiletov, and Ö. Gustafsson
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Atmospheric Science ,Global and Planetary Change ,Environmental Chemistry ,General Environmental Science - Published
- 2022
- Full Text
- View/download PDF
7. Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: a multi-biomarker reconstruction from Paru Co
- Author
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A. Callegaro, D. Battistel, N. M. Kehrwald, F. Matsubara Pereira, T. Kirchgeorg, M. D. C. Villoslada Hidalgo, B. W. Bird, and C. Barbante
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010504 meteorology & atmospheric sciences ,Environmental change ,Stratigraphy ,lcsh:Environmental protection ,Climate change ,010502 geochemistry & geophysics ,01 natural sciences ,chemistry.chemical_compound ,Ice core ,lcsh:Environmental pollution ,Settore CHIM/01 - Chimica Analitica ,lcsh:TD169-171.8 ,Global and Planetary Change ,Paleontology ,Holocene ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,lcsh:GE1-350 ,geography ,Plateau ,geography.geographical_feature_category ,Levoglucosan ,Sediment ,Vegetation ,15. Life on land ,chemistry ,13. Climate action ,lcsh:TD172-193.5 ,Environmental science ,Physical geography - Abstract
The fire history of the Tibetan Plateau over centennial to millennial timescales is not well known. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, can provide continuous records of local environmental change on millennial scales during the Holocene through the accumulation and preservation of specific organic molecular biomarkers. To reconstruct Holocene fire events and vegetation changes occurring on the southeastern Tibetan Plateau and the surrounding areas, we used a multi-proxy approach, investigating multiple biomarkers preserved in core sediment samples retrieved from Paru Co, a small lake located in the Nyainqentanglha Mountains (29∘47′45.6′′ N, 92∘21′07.2′′ E; 4845 m a.s.l.). Biomarkers include n-alkanes as indicators of vegetation, polycyclic aromatic hydrocarbons (PAHs) as combustion proxies, fecal sterols and stanols (FeSts) as indicators of the presence of humans or grazing animals, and finally monosaccharide anhydrides (MAs) as specific markers of vegetation burning processes. Insolation changes and the associated influence on the Indian summer monsoon (ISM) affect the vegetation distribution and fire types recorded in Paru Co throughout the Holocene. The early Holocene (10.7–7.5 cal kyr BP) n-alkane ratios demonstrate oscillations between grass and conifer communities, resulting in respective smouldering fires represented by levoglucosan peaks, and high-temperature fires represented by high-molecular-weight PAHs. Forest cover increases with a strengthened ISM, where coincident high levoglucosan to mannosan (L ∕ M) ratios are consistent with conifer burning. The decrease in the ISM at 4.2 cal kyr BP corresponds with the expansion of regional civilizations, although the lack of human FeSts above the method detection limits excludes local anthropogenic influence on fire and vegetation changes. The late Holocene is characterized by a relatively shallow lake surrounded by grassland, where all biomarkers other than PAHs display only minor variations. The sum of PAHs steadily increases throughout the late Holocene, suggesting a net increase in local to regional combustion that is separate from vegetation and climate change.
- Published
- 2019
8. Monte Carlo Simulation of the ±JHeisenberg Model in Parisi States
- Author
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Shinsuke Takahashi, F. Matsubara, and Takayuki Shirakura
- Subjects
Physics ,Magnetization ,Spin glass ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Heisenberg model ,Phase (matter) ,Transition temperature ,Monte Carlo method ,Condensed Matter::Statistical Mechanics ,Relaxation (physics) ,State (functional analysis) ,Condensed Matter::Disordered Systems and Neural Networks - Abstract
We performed Monte Carlo simulation of the three dimensional ±J Heisenberg model in a Parisi state. That is, having started with one of Parisi states A, we calculated the magnetization M A (t) projected on A. We found that at low temperatures (T < T SG ) M A (t) for small t exhibits a relaxation similar to that of the ferromagnetic phase, where T SG is the spin glass transition temperature estimated before. From this behavior, we estimated temperature dependence of the order parameter of that Parisi state.
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- 2005
- Full Text
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9. Parisi states in a Heisenberg spin-glass model in three dimensions
- Author
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Y. Baba, F. Matsubara, and Takayuki Shirakura
- Subjects
Physics ,Spin glass ,Heisenberg model ,FOS: Physical sciences ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Metastability ,Quantum mechanics ,Ising model ,Ground state ,Mathematical Physics ,Energy (signal processing) ,Excitation - Abstract
We have studied low-lying metastable states of the $\pm J$ Heisenberg model in two ($d=2$) and three ($d=3$) dimensions having developed a hybrid genetic algorithm. We have found a strong evidence of the occurrence of the Parisi states in $d=3$ but not in $d=2$. That is, in $L^d$ lattices, there exist metastable states with a finite excitation energy of $\Delta E \sim O(J)$ for $L \to \infty$, and energy barriers $\Delta W$ between the ground state and those metastable states are $\Delta W \sim O(JL^{\theta})$ with $\theta > 0$ in $d=3$ but with $\theta < 0$ in $d=2$. We have also found droplet-like excitations, suggesting a mixed scenario of the replica-symmetry-breaking picture and the droplet picture recently speculated in the Ising SG model., Comment: 4 pages, 6 figures
- Published
- 2004
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10. Three-dimensional Heisenberg spin-glass models with and without random anisotropy
- Author
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Shin-ichi Endoh, F. Matsubara, Takayuki Shirakura, and Saburo Takahashi
- Subjects
Physics ,Phase transition ,Spin glass ,Phase transition temperature ,Condensed matter physics ,Monte Carlo method ,FOS: Physical sciences ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Lattice (order) ,Exponent ,Anisotropy ,Scaling ,Mathematical Physics - Abstract
We reexamine the spin glass (SG) phase transition of the $\pm J$ Heisenberg models with and without the random anisotropy $D$ in three dimensions ($d = 3$) using complementary two methods, i.e., (i) the defect energy method and (ii) the Monte Carlo method. We reveal that the conventional defect energy method is not convincing and propose a new method which considers the stiffness of the lattice itself. Using the method, we show that the stiffness exponent $\theta$ has a positive value ($\theta > 0$) even when $D = 0$. Considering the stiffness at finite temperatures, we obtain the SG phase transition temperature of $T_{\rm SG} \sim 0.19J$ for $D = 0$. On the other hand, a large scale MC simulation shows that, in contrary to the previous results, a scaling plot of the SG susceptibility $\chi_{\rm SG}$ for $D = 0$ is obtained using almost the same transiton temperature of $T_{\rm SG} \sim 0.18J$. Hence we believe that the SG phase transition occurs in the Heisenberg SG model in $d = 3$., Comment: 15 pages, 9 figures, to be published in J. Phys. A
- Published
- 2003
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11. Heat transfer characteristics of a non-premixed turbulent flame formed in a curved rectangular duct
- Author
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Yasuhiko Ohta, F. Matsubara, and Masato Tagawa
- Subjects
Turbulent diffusion ,Turbulence ,Chemistry ,General Chemical Engineering ,Diffusion ,General Physics and Astronomy ,Energy Engineering and Power Technology ,Thermodynamics ,General Chemistry ,Reynolds stress ,Mechanics ,Physics::Fluid Dynamics ,Fuel Technology ,Heat transfer ,Duct (flow) ,Pressure gradient ,Schlieren photography - Abstract
Heat transfer characteristics of a non-premixed turbulent flame formed in a curved rectangular duct (180° bend) were investigated experimentally. Key turbulence quantities of velocity and thermal fields such as Reynolds stress components and turbulent heat fluxes were measured using a combined LDV and fine-wire thermocouple technique. These measurements provided direct evidence of the occurrence of the anomalous phenomenon of counter-gradient heat transfer, which can be ascribed to the presence of a strong pressure-gradient in the radial direction of the curved duct. The experiment also revealed that the onset region of this “counter-gradient” diffusion was adjacent to the strong “gradient” diffusion region. The quantitative appraisal of the production terms for the turbulent heat flux showed that the pressure gradient promoted gradient diffusion on the inner-wall (low-pressure) side of the curved-duct flame and caused counter-gradient diffusion on the outer-wall (high-pressure) side. The schlieren photography for visualizing the density field showed a totally different behavior of the burned gas parcels between the high- and low-pressure sides of the flame. The essential mechanism causing the counter-gradient diffusion can be explained by the unique motion of the high-temperature (low-density) gas parcel on the high-pressure side of the flame. High-temperature fluid motions tend to be preferentially damped by the pressure gradient imposed on the flow field. The occurrence of the counter-gradient diffusion phenomenon will of course lead to the collapse of the “gradient-diffusion hypothesis,” on which most conventional turbulence models rely. In such a field, the analogy between heat and mass transfer processes, which holds almost always in normal turbulent passive-scalar transport, can disappear.
- Published
- 2002
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12. Stiffness of the Heisenberg Spin-Glass Model at Zero- and Finite-Temperatures in Three Dimensions
- Author
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Shin-ichi Endoh, Takayuki Shirakura, and F. Matsubara
- Subjects
Physics ,Spin glass ,Phase transition temperature ,Condensed matter physics ,Spins ,FOS: Physical sciences ,General Physics and Astronomy ,Stiffness ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Lattice size ,Lattice (order) ,medicine ,Zero temperature ,medicine.symptom - Abstract
We examine the stiffness of the Heisenberg spin-glass (SG) model at both zero temperature (T=0) and finite temperatures ($T \ne 0$) in three dimensions. We calculate the excess energies at T=0 which are gained by rotating and reversing all the spins on one surface of the lattice, and find that they increase with the lattice size $L$. We also calculate the excess free-energies at $T \ne 0$ which correspond to these excess energies, and find that they increase with $L$ at low temperatures, while they decrease with increasing $L$ at high temperatures. These results strongly suggest the occurrence of the SG phase at low temperatures. The SG phase transition temperature is estimated to be $T_{\rm SG} \sim 0.19J$ from the lattice size dependences of these excess free-energies., Comment: 9pages, 8figures, submitted to J. Phys. Soc. Jpn
- Published
- 2001
- Full Text
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13. Magnetic properties of mesoscopic ultrathin magnetic films with uniaxial anisotropy
- Author
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J. Sasaki and F. Matsubara
- Subjects
Physics ,Magnetization ,Phase transition ,Mesoscopic physics ,Magnetic anisotropy ,Condensed matter physics ,Ferromagnetism ,Mean field theory ,General Physics and Astronomy ,Ising model ,Anisotropy - Abstract
We study magnetic properties of micron- and submicron-scale ultrathin ferromagnetic films with uniaxial anisotropy by means of a two-dimensional Ising model with both exchange and dipolar interactions using both a mean field approximation and a Monte Carlo method. We find that, in those films, the size of the surface area is an important parameter to determine their magnetic properties. In particular, we find three lattice size ranges A, B, and C. In the range A (small lattices), the model exhibits properties similar to those of a usual Ising model. In the range B (moderate lattices), the specific heat exhibits a double peak around T1 and T2 (
- Published
- 2000
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14. Equilibrium properties of an axial next-nearest-neighbor Ising model in two dimensions
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F. Matsubara and A. Sato
- Subjects
Physics ,Square-lattice Ising model ,Ising model ,Statistical physics ,k-nearest neighbors algorithm - Published
- 1999
- Full Text
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15. Phase diagram of
- Author
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S. Ohigashi, S. Niidera, and F. Matsubara
- Subjects
Materials science ,Spin glass ,Ferromagnetism ,Condensed matter physics ,Phase (matter) ,Monte Carlo method ,Condensed Matter::Strongly Correlated Electrons ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Phase diagram ,Spin-½ - Abstract
We have theoretically studied the spin ordering of Eu x Sr 1 - x S using a Monte Carlo method. We found the spin glass phase occurs for x 0.50 in addition to the ferromagnetic phase for x > 0.50 . An obtained phase diagram is in agreement with the experimental one fairly well.
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- 2007
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16. Reentrant spin-glass transition in a dilute Heisenberg ferromagnet
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F. Matsubara and S. Niidera
- Subjects
Physics ,Spin glass ,Condensed matter physics ,Heisenberg model ,Monte Carlo method ,Condensed Matter Physics ,Condensed Matter::Disordered Systems and Neural Networks ,Electronic, Optical and Magnetic Materials ,Magnetization ,Reentrancy ,Ferromagnetism ,Phase (matter) ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons - Abstract
We perform a large-scale Monte Carlo simulation of a dilute ferromagnetic Heisenberg model with antiferromagnetic next-nearest neighbor interactions. We find that the model reproduces a reentrant spin-glass (RSG) transition. That is, as the temperature is decreased, the magnetization M once increases rapidly below a certain temperature, reaches a maximum value, and then disappears at some lower temperature. The low-temperature phase is suggested to be a spin-glass (SG) phase that is characterized by ferromagnetic clusters. We present a possible mechanism responsible for the RSG transition.
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- 2007
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17. phase diagram of a 3D Heisenberg spin glass
- Author
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Yuichi Iyama, F. Matsubara, Takayuki Shirakura, and Daisuke Ninomiya
- Subjects
Physics ,Phase transition ,Spin glass ,Condensed matter physics ,Monte Carlo method ,Stiffness ,Critical magnetic field ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Exponent ,medicine ,medicine.symptom ,Phase diagram - Abstract
We study the three-dimensional (3D) ± J Heisenberg spin glass in a magnetic field. Two different methods are applied to examine the phase transition, i.e., an equilibrium Monte Carlo method and a non-equilibrium relaxation method. Both methods give qualitatively the same results. That is, the Gabay–Toulouse (GT) phase transition occurs at H ≠ 0 . We also calculate the stiffness exponent θ to estimate the critical magnetic field H c at T = 0 and give a phase diagram.
- Published
- 2007
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18. Thermodynamic properties of the quantum antiferromagnet on the triangular lattice in a magnetic field
- Author
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N. Suzuki and F. Matsubara
- Subjects
Physics ,Condensed matter physics ,Heisenberg model ,Quantum mechanics ,Antiferromagnetism ,Hexagonal lattice ,Quantum ,Lattice model (physics) ,Magnetic field - Published
- 1998
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19. Phase diagrams of the S= quantum antiferromagnetic XY model on the triangular lattice in magnetic fields
- Author
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N. Suzuki and F. Matsubara
- Subjects
Physics ,Magnetization ,Paramagnetism ,Condensed matter physics ,Ferrimagnetism ,Antiferromagnetism ,Ground state ,Classical XY model ,Magnetic field ,Spin-½ - Abstract
We study the S=1/2 quantum antiferromagnetic XY model on finite triangular lattices with N sites in both longitudinal and transverse magnetic fields. We calculate physical quantities in the ground state using a diagonalization for spins $N \leq 27$, and those at finite temperatures using a quantum transfer Monte Carlo method for $N \leq 24$. In the longitudinal magnetic field, the long-range chiral order parameter seems to have a finite, nonzero value at low temperatures suggesting the occurrence of a classical umbrella-type phase. In the transverse magnetic field, the 1/3-plateau of the magnetization curve appears even at low temperatures, in contrast with the classical model. The magnetic field dependences of the order parameters suggest that the chiral-ordered, the ferrimagnetic, and the spin flop phases appear successively as the magnetic field is increased. The transition temperatures are estimated from the peak position of the specific heat, and the phase diagrams are predicted in both longitudinal and transverse magnetic fields.
- Published
- 1997
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20. Fiber review in these 50 years ( Part six ) 50 years of silk
- Author
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F. Matsubara
- Subjects
SILK ,Materials science ,Polymers and Plastics ,Materials Science (miscellaneous) ,Fiber ,Composite material ,Industrial and Manufacturing Engineering - Published
- 1997
- Full Text
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21. Establishment of a rapid bone resorption in vitro assay using previiously frozen mouse unfractionated bone cells pretreated with parathyroid hormone
- Author
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M. Katoh, Masayoshi Kumegawa, K. Kitamura, O. Komiyama, F. Matsubara, and H. Kitagawa
- Subjects
medicine.medical_specialty ,Time Factors ,Histology ,Physiology ,Endocrinology, Diabetes and Metabolism ,Acid Phosphatase ,Osteoclasts ,Parathyroid hormone ,Bone resorption ,Andrology ,Leukocyte Count ,Mice ,Multinucleate ,Osteoclast ,Internal medicine ,Freezing ,Bone cell ,medicine ,Animals ,Bone Resorption ,Tartrates ,Cells, Cultured ,Mice, Inbred ICR ,biology ,Acid phosphatase ,Reproducibility of Results ,Resorption ,Endocrinology ,medicine.anatomical_structure ,Parathyroid Hormone ,Calcitonin ,Leukocytes, Mononuclear ,biology.protein ,Biological Assay - Abstract
We established a useful assay system for evaluating osteoclast-mediated bone resorption based on the use of unfractionated bone cells obtained from 10- to 11-day-old mice. When cells from 10 to 11 mice were treated for 7 days with rat parathyroid hormone (rPTH, 10(-8) M), a total of 4 to 5 x 10(7) cells could be obtained from the culture by treatment with 0.05% trypsin and 0.02% EDTA in PBS. These harvested cells contained about 20% tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells. When the harvested cells were cultured on dentine slices without rPTH, after 1 day, they formed TRAP-positive multinucleate cells that were active in bone resorption. Eel calcitonin (eCT) decreased the number of pits in a dose-dependent manner, and its half maximal inhibition dose (ID50) was 1.08 x 10(-11) M. Even after having been frozen in liquid nitrogen for 5 months, upon thawing, these cells were capable for forming pits; and this pit formation was inhibited by eCT. Since no appropriate osteoclastic cell line for evaluating bone resorption is available at present, this system can provide a useful, practical means for assaying osteoclastic bone-resorbing activity.
- Published
- 1993
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22. Ground-State Properties of a Heisenberg Spin Glass Model with a Hybrid Genetic Algorithm
- Author
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Yuh-ichi Iyama and F. Matsubara
- Subjects
Physics ,Spin glass ,Heisenberg model ,Mathematical analysis ,Crossover ,General Physics and Astronomy ,Perturbation (astronomy) ,Stiffness ,FOS: Physical sciences ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Genetic algorithm ,medicine ,Boundary value problem ,medicine.symptom ,Ground state - Abstract
We developed a genetic algorithm (GA) in the Heisenberg model that combines a triadic crossover and a parameter-free genetic algorithm. Using the algorithm, we examined the ground-state stiffness of the $\pm J$ Heisenberg model in three dimensions up to a moderate size range. Results showed the stiffness constant of $\theta = 0$ in the periodic-antiperiodic boundary condition method and that of $\theta \sim 0.62$ in the open-boundary-twist method. We considered the origin of the difference in $\theta$ between the two methods and suggested that both results show the same thing: the ground state of the open system is stable against a weak perturbation., Comment: 11 pages, 5 figures
- Published
- 2008
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23. Stochastic Cutoff Method for Long-Range Interacting Systems
- Author
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F. Matsubara and Munetaka Sasaki
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Particle system ,Physics ,Spins ,Statistical Mechanics (cond-mat.stat-mech) ,Stochastic modelling ,Monte Carlo method ,General Physics and Astronomy ,FOS: Physical sciences ,Detailed balance ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Dipole ,Dimension (vector space) ,Cutoff ,Statistical physics ,Condensed Matter - Statistical Mechanics - Abstract
A new Monte-Carlo method for long-range interacting systems is presented. This method consists of eliminating interactions stochastically with the detailed balance condition satisfied. When a pairwise interaction $V_{ij}$ of a $N$-particle system decreases with the distance as $r_{ij}^{-\alpha}$, computational time per one Monte Carlo step is ${\cal O}(N)$ for $\alpha \ge d$ and ${\cal O}(N^{2-\alpha/d})$ for $\alpha < d$, where $d$ is the spatial dimension. We apply the method to a two-dimensional magnetic dipolar system. The method enables us to treat a huge system of $256^2$ spins with reasonable computational time, and reproduces a circular order originated from long-range dipolar interactions., Comment: 18 pages, 9 figures, 1 figure and 1 reference are added
- Published
- 2007
24. Fluctuating clusters in a reentrant spin-glass system
- Author
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F. Matsubara and S. Niidera
- Subjects
Materials science ,Reentrancy ,Spin glass ,Spin polarization ,Condensed matter physics ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2007
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25. The self-organization of the orientation selectivity through learning by inhibitory interneurons
- Author
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Y. Musha, S. Inawashiro, F. Matsubara, and S. Miyake
- Subjects
Physics ,Artificial neural network ,business.industry ,Orientation (graph theory) ,Inhibitory postsynaptic potential ,Winner-take-all ,medicine.anatomical_structure ,Biological neural network ,Excitatory postsynaptic potential ,medicine ,Artificial intelligence ,Neuron ,Layer (object-oriented design) ,Biological system ,business - Abstract
A three-layered model of a neural network is proposed, where the learning by interneurons plays an important role in self-organizing the orientation selectivity. The first layer simply provides input patterns to the 2nd layer through plastic excitatory synapses and also to the 3rd layer through constant excitatory synapses. Each neuron of the 2nd layer gives inhibitory output to the corresponding neuron of the 3rd layer. Lateral inhibitions are also assumed among the neurons of the 3rd layers. The bar patterns of various orientation are applied as input to the neural network. After applying the input patterns for a long time, the synaptic strengths cease to be modified and come to an equilibrium. We carry out numerical calculations for the equilibrium and obtained the orientation selectivity in the 3rd layer of the output neurons. The numerical results are shown and discussed.
- Published
- 2005
- Full Text
- View/download PDF
26. Phase diagram of a dilute ferromagnet model with antiferromagnetic next-nearest-neighbor interactions
- Author
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S. Niidera, S. Abiko, and F. Matsubara
- Subjects
Physics ,Spin glass ,Condensed matter physics ,Statistical Mechanics (cond-mat.stat-mech) ,Heisenberg model ,FOS: Physical sciences ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Classical Heisenberg model ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Binder parameter ,Magnetization ,Phase (matter) ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Condensed Matter - Statistical Mechanics ,Phase diagram - Abstract
We have studied the spin ordering of a dilute classical Heisenberg model with spin concentration $x$, and with ferromagnetic nearest-neighbor interaction $J_1$ and antiferromagnetic next-nearest-neighbor interaction $J_2$. Magnetic phases at absolute zero temperature $T = 0$ are determined examining the stiffness of the ground state, and those at finite temperatures $T \neq 0$ are determined calculating the Binder parameter $g_L$ and the spin correlation length $\xi_L$. Three ordered phases appear in the $x-T$ phase diagram: (i) the ferromagnetic (FM) phase; (ii) the spin glass (SG) phase; and (iii) the mixed (M) phase of the FM and the SG. Near below the ferromagnetic threshold $x_{\rm F}$, a reentrant SG transition occurs. That is, as the temperature is decreased from a high temperature, the FM phase, the M phase and the SG phase appear successively. The magnetization which grows in the FM phase disappears in the SG phase. The SG phase is suggested to be characterized by ferromagnetic clusters. We conclude, hence, that this model could reproduce experimental phase diagrams of dilute ferromagnets Fe$_x$Au$_{1-x}$ and Eu$_x$Sr$_{1-x}$S., Comment: 9 pages, 23 figures
- Published
- 2005
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27. [Lung cancer with ground glass opacity diagnosed by transbronchial lung biopsy using an ultrathin bronchoscope and virtual bronchoscopy]
- Author
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Motoyasu, Sagawa, M, Sugita, K, Higashi, T, Isobe, T, Hirose, F, Matsubara, M, Ida, K, Isse, and T, Sakuma
- Subjects
Bronchoscopes ,Lung Neoplasms ,Biopsy ,Bronchoscopy ,Humans ,Female ,Glass ,Tomography, X-Ray Computed ,Lung ,Aged - Abstract
Although thoracic computed tomography (CT) screening indicated that there are many patients who have pulmonary shadow with ground glass opacity, it is sometimes difficult to obtain the appropriate specimens for histological diagnosis of such patients. We herein report a lung cancer patient with ground glass opacity who was diagnosed preoperatively by an ultrathin bronchoscope and virtual bronchoscopy. A 78-year-old female was admitted to our hospital due to bacterial pneumonia. At the admission, CT showed another abnormal small shadow in her right middle lobe. Since the shadow was not visible by fluoroscopy, we reconstructed the images of virtual bronchoscopy using the data obtained by multidetector CT. The location of the shadow was determined in the peripheral area of a dorsal branch of right B4aialpha. Then the transbronchial lung biopsy using an ultrathin bronchoscope with simultaneous CT guidance was performed. The histological findings of the biopsy specimens revealed that the shadow was highly suspicious for malignancy. Therefore, the right middle lobectomy was conducted, and the tumor was diagnosed as an adenocarcinoma. An ultrathin bronchoscope with virtual bronchoscopy is useful to diagnose a pulmonary shadow with ground glass opacity.
- Published
- 2004
28. Ground state and low-lying excitations in a Heisenberg spin-glass model in three dimensions
- Author
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F. Matsubara, Y. Baba, Saburo Takahashi, and Takayuki Shirakura
- Subjects
Physics ,Spin glass ,Condensed matter physics ,Heisenberg model ,Quantum mechanics ,Excited state ,Condensed Matter Physics ,Ground state ,Lying ,Electronic, Optical and Magnetic Materials ,Three dimensional model - Published
- 2004
- Full Text
- View/download PDF
29. Binder Parameter of a Heisenberg Spin-Glass Model in Four Dimensions
- Author
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F. Matsubara and Takayuki Shirakura
- Subjects
Maple ,Physics ,Phase transition ,Spin glass ,Condensed matter physics ,Heisenberg model ,FOS: Physical sciences ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,engineering.material ,Condensed Matter - Disordered Systems and Neural Networks ,Condensed Matter::Disordered Systems and Neural Networks ,Binder parameter ,Lattice (order) ,engineering ,Anisotropy - Abstract
We studied the phase transition of the $\pm J$ Heisenberg model with and without a random anisotropy on four dimensional lattice $L\times L\times L\times (L+1)$ $(L\leq 9)$. We showed that the Binder parameters $g(L,T)$'s for different sizes do not cross even when the anisotropy is present. On the contrary, when a strong anisotropy exists, $g(L,T)$ exhibits a steep negative dip near the spin-glass phase transition temperature $T_{\rm SG}$ similarly to the $p-$state infinite-range Potts glass model with $p \geq 3$, in which the one-step replica-symmetry-breaking (RSB) occurs. We speculated that a one-step RSB-like state occurs below $T_{\rm SG}$, which breaks the usual crossing behavior of $g(L,T)$., 4 pages including 4 figures, submitted to Phys. Rev. B
- Published
- 2002
30. Overexpression of p8 is inversely correlated with apoptosis in pancreatic cancer
- Author
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S B, Su, Y, Motoo, J L, Iovanna, P, Berthézène, M J, Xie, H, Mouri, K, Ohtsubo, F, Matsubara, and N, Sawabu
- Subjects
Aged, 80 and over ,Male ,DNA, Single-Stranded ,Gene Expression ,Apoptosis ,DNA, Neoplasm ,Middle Aged ,Immunohistochemistry ,Survival Analysis ,Neoplasm Proteins ,DNA-Binding Proteins ,Pancreatic Neoplasms ,Basic Helix-Loop-Helix Transcription Factors ,Bisbenzimidazole ,Humans ,Female ,Growth Substances ,Aged ,Fluorescent Dyes - Abstract
A recently identified gene, p8, has cell growth-promoting activity and is strongly induced in acute pancreatitis. In this study, we detected p8 and single-stranded DNA (ssDNA) for apoptosis by immunohistochemistry in human pancreatic cancer. The p8 was overexpressed (30% per 1000 cancer cells) in 26 of 44 (59%) pancreatic cancers, and apoptosis (ssDNA-positive cells10% per 1000 cancer cells) was recognized in 18 of 44 (41%) pancreatic cancers. There was a significant inverse correlation between the p8 overexpression and apoptosis (P0.05). Moreover, the expression pattern of high p8 and low ssDNA was seen significantly more often in lower age (65 years), in moderately or poorly differentiated cancers, and in node-positive cases (P0.05). The p8 expression and apoptosis were not significantly correlated with survival. These results suggest that p8 overexpression is involved in antiapoptotic activity and the biological characteristics of pancreatic cancer.
- Published
- 2001
31. Expression of p8 in human pancreatic cancer
- Author
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S B, Su, Y, Motoo, J L, Iovanna, M J, Xie, H, Mouri, K, Ohtsubo, Y, Yamaguchi, H, Watanabe, T, Okai, F, Matsubara, and N, Sawabu
- Subjects
Aged, 80 and over ,Male ,Reverse Transcriptase Polymerase Chain Reaction ,Gene Expression ,Middle Aged ,Polymerase Chain Reaction ,Neoplasm Proteins ,DNA-Binding Proteins ,Immunoenzyme Techniques ,Pancreatic Neoplasms ,Carcinoma, Adenosquamous ,Basic Helix-Loop-Helix Transcription Factors ,Tumor Cells, Cultured ,Humans ,Female ,RNA, Messenger ,Growth Substances ,Aged ,Carcinoma, Pancreatic Ductal ,DNA Primers - Abstract
The p8 gene is a recently identified gene with mitogenic activity. p8 expression is induced in acute pancreatitis, pancreatic development, and regeneration. However, the expression of p8 in pancreatic cancer is not reported. We investigated p8 expression in 72 human pancreatic tissues, including 38 pancreatic cancers (PCs), by immunohistochemistry. p8 was overexpressed (positive cells25% in 1,000 cells) in 71% (27 of 38) of PCs, but in only 17% (3 of 18) of chronic pancreatitis cases. There was no overexpression in mucinous cystadenoma or in normal pancreas. The p8 overexpression rate in PC was significantly higher than that in other conditions (P0.05). Reverse transcription-PCR analysis confirmed p8 mRNA overexpression (tumor/nontumor ratio2) in 75% (3 of 4) of PCs. p8 was overexpressed also in human pancreatic cancer cell lines (MIA PaCa-2 and PANC-1). These results suggest that p8 is involved in the development of pancreatic cancer, reflecting its mitogenic activity.
- Published
- 2001
32. Effect of simulating temperature to resemble hyperthermia therapy on thermal stability of thyroxin-binding globulin
- Author
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T Hashimoto and F Matsubara
- Subjects
medicine.medical_specialty ,Endocrinology ,Chemistry ,Thyroxin-Binding Globulin ,medicine.medical_treatment ,Internal medicine ,Biochemistry (medical) ,Clinical Biochemistry ,medicine ,Thermal stability ,Hyperthermia therapy - Published
- 1990
- Full Text
- View/download PDF
33. Low Temperature Phase of Asymmetric Spin Glass Model in Two Dimensions
- Author
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T. Shirakura and F. Matsubara
- Subjects
Physics ,Phase transition ,Spin glass ,Condensed matter physics ,Heat bath ,Lattice (order) ,General Physics and Astronomy ,FOS: Physical sciences ,Ising model ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Power law ,Scaling - Abstract
We investigate low temperature properties of a random Ising model with $+J$ and $-aJ (a \neq 1)$ bonds in two dimensions using a cluster heat bath method. It is found that the Binder parameters $g_L$ for different sizes of the lattice come together at almost the same temperature implying the occurrence of the spin glass(SG) phase transition. From results of finite size scaling analyses, we suggest that the SG phase really occurs at low temperatures which is characterized by a power law decay of spin correlations., Comment: 9 pages, 5 Postscript figures, REVtex
- Published
- 1997
- Full Text
- View/download PDF
34. Computer simulation of magnetic domains in ultrathin magnetic films with a few monolayers
- Author
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F. Matsubara and S Endoh
- Subjects
Physics ,Condensed matter physics ,Magnetic domain ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Physics::Fluid Dynamics ,Condensed Matter::Materials Science ,Magnetization ,Condensed Matter::Superconductivity ,Monolayer ,Magnetic films ,Thin film ,Anisotropy ,Magnetic bubbles ,Spin (physics) - Abstract
We performed a Monte-Carlo simulation of magnetic domains in an ultrathin film with surface anisotropy. We found that the out-of-plane spin component S i ⊥ forms magnetic domains and that the shape of the domains is closely related to the arrangement of the in-plane spin component S i || . When in-plane magnetization is absent ( M || =0), isolated bubble-like domains of S i ⊥ appear, whereas stripe domains appear when M || ≠0. The bubble-like domains were found in thin films, and the stripe domains were found in less thin films.
- Published
- 2004
- Full Text
- View/download PDF
35. Expression of the Newcastle disease virus (NDV) fusion glycoprotein and vaccination against NDV challenge with a recombinant baculovirus
- Author
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H, Mori, H, Tawara, H, Nakazawa, M, Sumida, F, Matsubara, S, Aoyama, Y, Iritani, Y, Hayashi, and K, Kamogawa
- Subjects
Gene Expression Regulation, Viral ,Newcastle Disease ,Newcastle disease virus ,Animals ,Viral Vaccines ,Transfection ,Chickens ,Viral Fusion Proteins ,Nucleopolyhedroviruses ,Plasmids - Abstract
The hybrid baculovirus constructed from Autographa california nuclear polyhedrosis virus (NPV) and Bombyx mori (silkworm) NPV was used for expression of fusion glycoprotein (F) of Newcastle disease virus (NDV) strain D26. The gene encoding F protein was introduced into the improved baculovirus expression vector derived from the host-range-expanded baculovirus. In Spodoptera frugiperda (fall armyworm) cells infected with a recombinant baculovirus, HyF121, the expressed F protein was properly located onto the cell surface. After silkworm pupae were infected with HyF121, a subunit vaccine against NDV was prepared from the HyF121-infected pupae. Chickens inoculated with the subunit vaccine were protected against virulent NDV challenge.
- Published
- 1994
36. [Modified CHOP and radiation therapy in an aged patient with angioendothelial lymphoma]
- Author
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C, Hisano, Y, Asano, K, Ohe, F, Matsubara, O, Okamoto, G, Shiraishi, and H, Okubo
- Subjects
Male ,Lymphoma, B-Cell ,Chemotherapy, Adjuvant ,Doxorubicin ,Vincristine ,Adrenal Glands ,Antineoplastic Combined Chemotherapy Protocols ,Adrenal Gland Neoplasms ,Humans ,Prednisone ,Cyclophosphamide ,Aged - Abstract
A 77-year-old man was admitted because of high fever and general malaise. Whole-body CT showed large bilateral adrenal masses and para-aortic lymphadenopathy. Needle biopsy of the adrenal mass revealed mononuclear tumor cells within the lumens of small vessels, indicating the features of angioendothelial lymphoma. Immunohistochemically, these tumor cells were B cell lineage (positive for LCA, Mx-pan B, MB-1, and negative for factor VIII-related antigen, UEA-1, QB/ENDO 10). We used a modified CHOP therapy (500 mg of cyclophosphamide, 40mg of 4'-o-tetrahydropyranyl doxorubicin, 2mg of vindesine, and 50 mg of prednisolone) due to the patient's advanced age and general condition. Following the first course of this modified CHOP, the adrenal masses and para-aortic lymph nodes decreased dramatically in size, and his subjective symptoms also improved remarkably. Following three courses of modified CHOP, the patient developed dementia and disturbance of consciousness. Brain MRI revealed enhanced multiple nodular lesions. A diagnosis of multiple brain metastasis was made and modified CHOP and radiation therapy were begun, which relieved his symptoms for some time. However, he later died of pneumonia with severe leukopenia. A postmortem examination was performed. Microscopic examination showed no residual tumor cells in the adrenal gland. brain lymph nodes, or other organs. These results suggest that modified CHOP and radiation therapy may have beneficial anti-tumor effects against angioendothelial lymphoma.
- Published
- 1994
37. Gabay–Toulouse phase transition in Heisenberg spin glasses in three dimensions
- Author
-
Y. Iyama, D. Ninomiya, F. Matsubara, and Takayuki Shirakura
- Subjects
Statistics and Probability ,Chirality ,Physics ,Phase transition ,Spin glass ,Condensed matter physics ,Heisenberg model ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Condensed Matter::Disordered Systems and Neural Networks ,Magnetic field ,Modeling and Simulation ,Exponent ,Anisotropy ,Spin (physics) ,Mathematical Physics - Abstract
We examine three-dimensional ±J Heisenberg models with and without random anisotropies in a magnetic field. We calculate both the stiffness exponent θs at zero temperature and spin-glass correlation lengths for the longitudinal and transverse spin components at finite temperatures. We suggest that, contrary to a chirality scenario predicted by Kawamura and his co-workers (Kawamura 1992 Phys. Rev. Lett. 68 3785, 1998 Phys. Rev. Lett. 80 5421, Hukushima and Kawamura 2000 Phys. Rev. E 61 R1008), a Gabay–Toulouse phase transition might occur when the anisotropies are absent, although the results, except for the correlation length of the chirality for larger sizes, suggest no phase transition when they are present.
- Published
- 2009
- Full Text
- View/download PDF
38. Evaluation of a new chemiluminescence technique for human thyrotropin (BeriLux hTSH): diagnostic value of five immunometric assay methods
- Author
-
T, Hashimoto, F, Matsubara, M, Nishibu, and K, Kawai
- Subjects
Adult ,Immunoassay ,Male ,Methimazole ,Thyrotropin ,Middle Aged ,Graves Disease ,Immunoenzyme Techniques ,Thyroxine ,Evaluation Studies as Topic ,Propylthiouracil ,Luminescent Measurements ,Humans ,Triiodothyronine ,Female ,Immunoradiometric Assay ,Thyrotropin-Releasing Hormone - Abstract
A new commercially available human thyrotropin immunochemiluminometric assay (ICMA) kit was evaluated. The BeriLux assay (Hoechst Co., Germany) was compared with two other non-radioisotopic methods (AIA-1200 and IMx) and two other immunoradiometric assays (RIA-gnost TSH IRMA and EIKEN IRMA kits) in 32 normal subjects and 104 patients with Graves' disease, divided into seven groups: 1) untreated hyperthyroidism; 2) hyperthyroidism during treatment; 3) euthyroid with negative thyroliberin test (subclinical hyperthyroidism); 4) euthyroid with low thyroliberin test; 5) euthyroid with normal thyroliberin test; 6) euthyroid with high thyrotropin level (subclinical hypothyroidism); and 7) primary hypothyroidism. Patients in groups 2-6 were undergoing treatment with mercazole and propylthiouracil. The new immunoluminometric assay (ILMA) BeriLux kit was shown to have a remarkably improved analytical and clinical sensitivity. The minimal detectable level of thyrotropin in the assay was 0.006 mU/l. The precision was 2.8% and 6.1% at 0.093 +/- 0.003 mU/l and 0.028 +/- 0.002 mU/l, respectively, whereas the precision of the other methods was above 17.2% and 59.4% respectively. Seven patients from the untreated hyperthyroid group were given 500 micrograms thyroliberin i.v. (the thyroliberin test). The thyrotropin pattern before and after thyroliberin administration was always less than 0.006 mU/l with the BeriLux kit, whereas the other methods showed random fluctuations indicating their low accuracy at this concentration. Using the BeriLux kit, 7 of the 16 overt hyperthyroid patients undergoing treatment showed a measurable thyrotropin level below 0.01 mU/l but a negative thyroliberin test.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1991
39. [Thyroid dysfunction and histologic correlation using thyroid needle biopsy specimens]
- Author
-
Y, Mizukami, T, Michigishi, A, Nonomura, T, Hashimoto, and F, Matsubara
- Subjects
Adult ,Hypothyroidism ,Biopsy, Needle ,Thyroid Gland ,Thyroiditis, Autoimmune ,Humans ,Female ,Puerperal Disorders ,Middle Aged ,Prognosis ,Hyperthyroidism ,Thyroid Diseases ,Aged - Abstract
In this article, we describe the usefulness of thyroid needle biopsy in the differential diagnosis of thyroid disorders revealing unusual thyroid function. Firstly, we describe the relationship between thyroid function and its histology in 601 cases of chronic thyroiditis. In the histologic group A, the majority of the cases showed a latent or overt hypothyroidism and in histologic group B, hyperthyroid, euthyroid and latent hypothyroid cases were found in nearly equal frequency, respectively. In histologic group C, most cases were in euthyroid and in histologic group D, most cases showed a hyperthyroidism. In the silent thyroiditis and postpartum thyroiditis, known to show a characteristic clinical and laboratory finding, the histologic features of thyroid gland were as follows: the observed characteristic histologic changes in both diseases were an extensive follicular destruction associated with chronic diffuse thyroiditis. These destructive changes disappeared in association with the clinical and laboratory recovery. In the patients with iodine-excess hypothyroidism, the thyroid glands also revealed characteristic histologic changes. A marked hyperplastic change of follicular cells and a lack of colloid material in the follicular lumen was the predominant histologic feature. Based on our personal experiences, thyroid needle biopsy should be recommended as a useful tool for differentiation of causes of hyper- or hypothyroidism.
- Published
- 1991
40. [Recent developments of measurements for pituitary-thyroid hormones: evaluation of five immunometric assay methods (RI and non RI methods]
- Author
-
T, Hashimoto, M, Nishibu, K, Kawai, H, Horita, T, Ayukawa, and F, Matsubara
- Subjects
Thyroxine ,Evaluation Studies as Topic ,Radioimmunoassay ,Humans ,Thyrotropin ,Triiodothyronine ,Immunoradiometric Assay ,Reagent Kits, Diagnostic ,Sensitivity and Specificity - Abstract
We evaluated five commercially available immunoassay kits for pituitary-thyroid function tests. The possible interference in analysis by immunoglobulin G (IgG) has also been examined. The BeriLux TSH assay kit (Hoechst co. FRG) was compared with two other non-RI methods (AIA-1200 and IMx) and two other immunoradiometric assays (RIA-gnost TSH IRMA and EIKEN IRMA kits) in 32 normal subjects and 92 patients with Graves' disease. The new ICMA BeriLux kit had a marked improved analytical and clinical sensitivity. The minimal detectable level of TSH in the assay was 0.006 mU/l. The precision was 2.8% and 6.1% at 0.093 +/- 0.003 mU/l and 0.028 +/- 0.002 mU/l, respectively, whereas the levels for the other methods were above 17.2% and 59.4% respectively. The TSH pattern was always less than 0.006 mU/l with the BeriLux kit, before and after TRH administration whereas the other methods showed random fluctuations which indicated their low accuracy at this concentration. This new ICMA BeriLux kit appears far more reliable than the ordinary immunometric assay kits.
- Published
- 1991
41. [EEG data filing system with personal computer and magneto-optical disc]
- Author
-
K, Kitamura, Y, Takizawa, A, Nishitani, H, Futamata, F, Matsubara, T, Furuta, I, Jibiki, and N, Yamaguchi
- Subjects
Microcomputers ,Filing ,Humans ,Electroencephalography ,Signal Processing, Computer-Assisted - Abstract
We established a new computerized EEG filing system, in which an EEG machine was connected to an EEG filing unit which consisted of a personal computer with a 32 bit CPU, 18 channel analog -to-digital and digital-to-analog converters, and a magneto-optical disc driver. This system has the following merits. The system was space-saving, the space required to store the EEG data, being only 1/500 of that required for storing EEG record. Though the system had two independent EEG filing units, our original file configuration enabled us to have access to all of the recorded EEG data anytime for more than 10 years. The system enabled us to display EEG data continuously on the high resolution CRT, just as if turning the page of an EEG record paper, and through the quick scanning, enabled us to view the entire EEG pattern. Furthermore, the system enabled us to conduct reliable digital analysis for EEG data by entering the EEG data without artifacts into a data processor after confirmation on the display. In the system, we used data files with the MS-DOS operating system. This enabled us to analyze the data obtained by a personal computer operating on other systems, by transferring the data to a floppy disc operating on our system. Our EEG filing system allows quick access to data as well as mass data storage.
- Published
- 1991
42. Immunohistochemical study of oncogene product ras p21, c-myc and growth factor EGF in breast carcinomas
- Author
-
Y, Mizukami, A, Nonomura, M, Noguchi, T, Taniya, N, Koyasaki, Y, Saito, T, Hashimoto, F, Matsubara, and N, Yanaihara
- Subjects
Epidermal Growth Factor ,Genes, myc ,Antibodies, Monoclonal ,Breast Neoplasms ,Prognosis ,Antibodies ,Proto-Oncogene Proteins c-myc ,Proto-Oncogene Proteins p21(ras) ,Carcinoma, Intraductal, Noninfiltrating ,Genes, ras ,Biomarkers, Tumor ,Humans ,Female ,Carcinoma in Situ ,Follow-Up Studies ,Neoplasm Staging ,Retrospective Studies - Abstract
The expression of the oncogene products ras p21, c-myc and the growth factor EGF (epidermal growth factor) was studied immunohistochemically in the tissue of 119 benign and malignant human breasts. In most cases, histologically normal breast tissues and benign lesions were found to be negative or poorly-expressive for reactivity with each antibody. Similar findings were observed in carcinoma in situ. Invading breast carcinomas demonstrated a significantly higher percentage of stained cells than that observed in benign lesions or carcinoma in situ; forty-two of 66 invasive breast carcinomas (63.6%) were highly-expressive for ras p21, thirty-eight (57.6%) for c-myc and twenty (30.3%) for EGF, but overall correlations between each oncogene expression and the clinical stage, tumor size or degree of differentiation were not found. The overall 5-year survival rate was studied in 58 patients with Stage II and III in association with each oncogene or EGF expression. Their survival rate was significantly effected by the EGF expression (0.05 less than p less than 0.1) but not by ras p21 or c-myc expression. Analysis of 36 specimens available with ER (estrogen-receptor) level revealed a significant correlation between the ER status and c-myc or E2 (estradiol) and a significant inverse correlation between ER status and ras p21 or EGF expression (P less than 0.05). The expression of ras p21, EGF and c-myc was not associated with metastatic tumor progression.
- Published
- 1991
43. Studies on endocrine changes induced by 8 MHz local radiofrequency hyperthermia in patients with bladder cancer
- Author
-
T. Hashimoto, F Matsubara, Haruo Hisazumi, and Kazuyoshi Nakajima
- Subjects
Adult ,Male ,endocrine system ,Cancer Research ,medicine.medical_specialty ,Physiology ,Thyroxine-binding globulin ,Thyroxine-Binding Proteins ,Physiology (medical) ,Internal medicine ,Endocrine Glands ,medicine ,Humans ,Hormone metabolism ,Aged ,Triiodothyronine ,biology ,business.industry ,Hyperthermia, Induced ,Middle Aged ,Prolactin ,Hormones ,Thyroxine ,Endocrinology ,Urinary Bladder Neoplasms ,biology.protein ,Thyroxine-binding proteins ,business ,Luteinizing hormone ,hormones, hormone substitutes, and hormone antagonists ,Hormone ,Endocrine gland - Abstract
To elucidate changes in hormone metabolism, especially thyroid, cortisol and sex hormone metabolism, during acute local heat stress, serum-free thyroxine (FT4), free tri-iodothyronine (FT3), reverse T3 (rT3), thyroxine binding globulin (TBG) and a number of other hormone levels [thyroid-stimulating hormone, thyroglobulin, calcitonine, luteinizing hormone, follicle-stimulating hormone, prolactin, growth hormone, cortisol and testosterone] were measured sequentially in 11 male patients with bladder cancer during and after local radiothermotherapy treatment. Hyperthermia was administered using 8 MHz radiofrequency (RF) capacity equipment. The core temperature was raised from 37 to 42 degrees C and maintained at 42 degrees C for 1 h. No significant change in hormone levels except for a slight decrease in TBG levels was observed. The clinical results indicated that 8 MHz RF hyperthermia at 42 degrees C can be applied safely as a therapeutic measure in patients with bladder tumours. Further studies concerning the changes in TBG are necessary in patients with other tumours, especially those with the complication of subclinical hyperthyroidism, to detect any corresponding rises in FT3 and FT4 levels. The effects of using higher temperatures also need to be examined.
- Published
- 1991
44. [Immunochemical analysis of two peak M proteinemia derived from structural differences of IgG Fc region]
- Author
-
J, Okumura, M, Nagahara, Y, Mizukami, T, Hashimoto, F, Matsubara, and S, Migita
- Subjects
Electrophoresis, Agar Gel ,B-Lymphocytes ,Molecular Structure ,Immunoglobulin G ,Humans ,Cell Differentiation ,Female ,Multiple Myeloma ,Aged ,Immunoglobulin Fc Fragments - Abstract
We found M-proteins with two peaks by agarose electrophoresis in the serum of a myeloma patient. The M-proteins were identified as both IgG 1-kappa type, and classified as IgG-F (fast mobility) and IgG-S (slow mobility). 1) The possibility that the two M-proteins were derived from the post translational differences of sugar moieties of the same IgG molecule was unlikely, because no migration changes were observed in IgG-F and IgG-S after the treatment with 4 different sugar enzymes. 2) Fab fractions of IgG-F and IgG-S were analyzed. After papain or pepsin digestion, western blotting with anti-Fab antiserum revealed that the Fab fraction of IgG-F and IgG-S had identical mobility by agarose electrophoresis. However the Fc fractions of IgG-F and IgG-S analyzed by the same procedures with anti-Fe antiserum, were different. 3) Anti-idiotype antiserum prepared in rabbits against IgG-S, or -F, and absorbed by normal IgG and normal human serum showed a fused precipitin line with IgG-F and IgG-S. These findings suggest that two M-proteins with both IgG 1 and kappa type, have the same VH and VL regions but have different constant regions of heavy chain. Since one copy of IgG 1 constant gene is found in each human haploid gene. It is speculated that the switching of the rearranged VDJ gene to constant region gene occurred not only between cis chromosome but also between trans chromosome.
- Published
- 1991
45. The need for primary quality control of commercially available immunoassay kits
- Author
-
T Hashimoto and F Matsubara
- Subjects
Gynecology ,Quality Control ,medicine.medical_specialty ,medicine.diagnostic_test ,media_common.quotation_subject ,Radioimmunoassay ,Monitoring system ,General Medicine ,Biology ,Luteinizing Hormone ,Reference Standards ,Luteinising hormone ,World health ,Pathology and Forensic Medicine ,Immunoassay ,medicine ,Medical physics ,Quality (business) ,Reagent Kits, Diagnostic ,Reference standards ,media_common ,Research Article - Abstract
Discrepancies among three commercially available luteinising hormone (LH) radioimmunoassay RIA kits, all calibrated against the second-IRP-HMG (World Health Organisation International Laboratory for Biological Standards), were observed. Even though the Japan Radioisotope Association carries out external quality control in Japan every year, inaccuracies still exist. This problem also exists elsewhere, and it is proposed that a global monitoring system of primary quality control (PQC) should be introduced by a body such as the World Health Organisation.
- Published
- 1991
46. [Potentiating effect of spirometric maneuver on bronchial responsiveness to methacholine in asthmatic subjects--the role of deep inspiration and forced expiration]
- Author
-
Y, Kamio, M, Fujimura, H, Futamata, F, Matsubara, and T, Matsuda
- Subjects
Adult ,Male ,Inhalation ,Bronchospirometry ,Respiration ,Humans ,Bronchi ,Female ,Forced Expiratory Flow Rates ,Middle Aged ,Asthma ,Bronchial Provocation Tests ,Methacholine Chloride - Abstract
We previously reported that spirometric maneuver (SM) had potentiating effect on bronchial responsiveness (BR) in asthmatic subjects but not in normal subjects. SM consists of deep inspiration to TLC (DI) and forced expiration to RV (FE). In this study, we examined the effect of SM, DI and FE on BR in 9 asthmatic subjects. Provocative concentration of methacholine producing a 35% fall in respiratory conductance (PC35-Grs) was significantly (p less than 0.02 and p less than 0.025) decreased from 0.34 mg/ml (GSEM, 1.51) to 0.16 mg/ml (GSEM, 1.45) and 0.14 mg/ml (GSEM, 1.51) by SM and DI, respectively but it was not altered by FE. These findings indicate that potentiating effect of SM on BR which is characteristic of asthma may be due to DI effect.
- Published
- 1990
47. [Study of quantitative measurement of tricuspid regurgitation using Doppler echocardiography]
- Author
-
Y, Takizawa, H, Futamata, N, Yoshimoto, H, Mukai, and F, Matsubara
- Subjects
Adult ,Aged, 80 and over ,Male ,Humans ,Female ,Middle Aged ,Echocardiography, Doppler ,Tricuspid Valve Insufficiency ,Aged - Abstract
The volume of tricuspid regurgitation (VTR) was measured using two-dimensional color and continuous wave Doppler echocardiography. The value of VTR showed significant correlations with the maximum area (r = 0.77), the maximum distance (r = 0.73) and the maximum width (r = 0.59) in the regurgitant signal, right ventricular pressure (r = 0.63) and the diameter of right atrium (r = 0.40). When the tricuspid regurgitation was divided into two types in viewpoint of its flow direction-flow directed to center of atrium (A type) and that directed to atrial septum (B type), VTR showed closer correlations with the maximum area (r = 0.90) and the maximum distance (r = 0.87) in A type. But in B type, their relativities were decreased (r = 0.51 and r = 0.40, respectively). The VTR was well related with the severity of tricuspid regurgitation based on the Miyatake's classification. This evidence indicated that the quantitative measurement of tricuspid regurgitant volume using two-dimensional color and continuous wave Doppler echocardiography is more accurate and useful compared with conventional semi-quantitative method.
- Published
- 1990
48. Serum thyroxin binding globulin (TBG) changes during 8 MHz local radiofrequency hyperthermia
- Author
-
H. Hisazumi, T. Hashimoto, and F. Matsubara
- Subjects
Hyperthermia ,Adult ,Male ,medicine.medical_specialty ,Protein Denaturation ,Chemistry ,Biochemistry (medical) ,Clinical Biochemistry ,General Medicine ,Middle Aged ,medicine.disease ,Biochemistry ,Biological fluid ,Short-Wave Therapy ,Thyroxine ,Thyroxine-Binding Proteins ,Endocrinology ,Urinary Bladder Neoplasms ,Thyroxin-Binding Globulin ,Internal medicine ,medicine ,Humans ,Triiodothyronine ,Aged - Published
- 1990
49. Immunohistochemical demonstration of growth factors, TGF-alpha, TGF-beta, IGF-I and neu oncogene product in benign and malignant human breast tissues
- Author
-
Y, Mizukami, A, Nonomura, T, Yamada, H, Kurumaya, M, Hayashi, N, Koyasaki, T, Taniya, M, Noguchi, S, Nakamura, and F, Matsubara
- Subjects
Adult ,Receptor, ErbB-2 ,Breast Neoplasms ,Middle Aged ,Transforming Growth Factor alpha ,Immunohistochemistry ,Receptors, Estrogen ,Transforming Growth Factor beta ,Proto-Oncogene Proteins ,Humans ,Female ,Breast ,Insulin-Like Growth Factor I ,Receptors, Progesterone ,Aged - Abstract
The expression of growth factors, TGF-alpha, TGF-beta, IGF-I and neu oncogene product was studied immunohistochemically in the tissue of 120 benign and malignant human breasts. Growth factors were found only in benign or malignant mammary epithelial cells and not in stromal cells. Normal and benign lesions were found to be negative for reactivity with each antibody. Carcinoma in situ and invasive breast carcinomas demonstrated a significantly higher percentage of stained cells than that observed in benign lesions; forty (49%) of 82 invasive carcinomas were positive for TGF-alpha, 31 (38%) for TGF-beta, 31 (38%) for IGF-I and 34 (41%) for neu product. No overall correlations were found between expression of each growth factor and the clinical stage or degree of histologic differentiation of the carcinomas. A significant positive correlation was observed between ER status and IGF-I expression and between PgR status and TGF-beta expression. In the majority of the carcinomas, co-expression between TGF-alpha, TGF-beta and IGF-I was observed; the percentage of cases with parallel positive or negative expression of two growth factors was as follows; TGF-alpha - TGF-beta (70%), TGF-alpha - IGF-I (57%), TGF-beta - IGF-I (71%). The concomitant expression of TGF-alpha and neu oncogene product in cell surface was also observed. The relapse-free intervals of the patients were studied in association with expression of each growth factor. TGF-beta-positive tumors showed a significantly better prognosis than TGF-beta - negative tumors (within the first 2 years of observation). However, TGF-alpha, IGF-I and neu overexpression showed no effect on the prognosis of the patients.
- Published
- 1990
50. Discordant CA 125 measurements in normal healthy women
- Author
-
T, Hashimoto, N, Ohba, and F, Matsubara
- Subjects
Adult ,Immunoenzyme Techniques ,Health Status ,Humans ,Antigens, Tumor-Associated, Carbohydrate ,False Positive Reactions ,Female ,Immunoradiometric Assay ,Reagent Kits, Diagnostic - Published
- 1990
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