Showing papers by "Tohoku University published in 1980"

Establishment and characterization of a human acute monocytic leukemia cell line (THP‐1)

Abstract: A human leukemic cell line (THP-1) cultured from the blood of a boy with acute monocytic leukemia is described. This cell line had Fc and C3b receptors, but no surface or cytoplasmic immunoglobulins. HLA haplotypes of THP-1 were HLA-A2, -A9, -B5, -DRW1 and -DRW2. The monocytic nature of the cell line was characterized by: (1) the presence of alpha-naphthyl butyrate esterase activities which could be inhibited by NaF; (2) lysozyme production; (3) the phagocytosis of latex particles and sensitized sheep erythrocytes; and (4) the ability to restore T-lymphocyte response to Con A. The cells did not possess Epstein-Barr virus-associated nuclear antigen. These results indicate that THP-1 is a leukemia cell line with distinct monocytic markers. During culture, THP-1 maintained these monocytic characteristics for over 14 months.

Horizontal Symmetry and Masses of Neutrinos

Abstract: Assuming a horizontal symmetry SU_F(n), we demonstrate a possibility that the left-handed neutrinos receive masses of order 1eV, which is consistent with recent experiments on neutrino oscillations. The smallness of the neutrino masses is an indication of a large breaking of the horizontal symmetry.

Direct Simulation Scheme Derived from the Boltzmann Equation. I. Monocomponent Gases

Abstract: The stochastic law that prescribes the velocities of simulated molecules after a small time increment was derived from the Boltzmann equation. The scheme to determine the velocity of a molecule after a small time increment is divided into three steps. The first step gives the collision probability of the molecule without specifying its collision partner. The second step gives a conditional probability distribution. If the molecule is accepted in the first step as a colliding molecule, its collision partner is sampled from this probability distribution. The last step gives a probability density from which the direction of the relative velocity after collision is sampled, and hence the step gives the post-collision velocity of the molecule. It is shown that the use of the present simulation scheme gives an exact solution of the Boltzmann equation.

Perpendicular magnetic recording

Abstract: This paper describes the recent studies for the magnetic head, the medium and the recording properties on a new perpendicular magnetic recording system. The complemental features between the perpendicular and the longitudinal recording are discussed to establish an efficient magnetic recording system. Superior response in the amplitude and the peak shift characteristics for a digital signal proves that the perpendicular magnetization mode is basically free from the recording demagnetization in high densities and the maximum density has been limited merely by the resolution of the reproducing head. Significant improvement for the recording and the reproducing sensitivities of a perpendicular head has been made by using a composite anisotropy medium composed by double layers of Fe-Ni and Co-Cr thin films.

Multi‐institutional Study on the Teratogenicity and Fetal Toxicity of Antiepileptic Drugs: A Report of a Collaborative Study Group in Japan

Abstract: Summary: A multi-institutional collaborative study was conducted concerning the course of pregnancy and delivery and the incidence of abnormal infants delivered of epileptic women. Of 657 women receiving antiepileptic drugs, 73% delivered live infants, 14% had miscarriage or stillbirth, and 13% underwent induced abortion. In contrast to the above findings, 80% of 162 patients not receiving antiepileptic drugs delivered live infants and 4% had miscarriage or stillbirth. The latter outcome was significantly increased in the medicated patients. In this series, 63 (9.9%) of 638 live births were malformed, 55 (11.5%) being from medicated mothers and 3 (2.3%) from nonmedicated mothers. The incidence of fetal malformation in medicated mothers was thus five times as high as that in nonmedicated mothers. Cleft lip and/or palate and malformations involving the cardiovascular system were found frequently in the infants from medicated mothers. General background factors that might exert teratogenic effects on pregnant patients with epilepsy were studied, and the potential toxicity of antiepileptic drugs to the fetus was also analyzed. In this regard, consideration should be given to whether the patient has partial epileptic seizures, whether the patient herself exhibits any malformation, or whether her previous pregnancy resulted in an abnormal outcome. The incidence of fetal malformation was the highest (12.7%) in the medicated patients who had epileptic seizures during the pregnancy. It is presumed on the basis of the results of analysis of the data that a combination of more than three drugs and a daily dose greater than a certain minimal level is likely to produce malformed infants. ZUSAMMENFASSUNG In vielen Institutionen wurde eine kollaborative Studie uber den Verlauf der Schwangerschaft, der Geburt und die Haufigkeit von Abnormitaten bei Kin-dern von Schwangeren mit Epilepsie durchgefuhrt. 73% der 657 Frauen unter antiepileptischer Therapie bekamen lebende Kinder, 14% hatte eine Fehl- oder Totgeburt und bei 13% wurde ein Abort eingeleitet ImGegensatz zu diesen Ergebnissen hatten 80% von 162 Patienten ohne Antiepileptica Lebendgeburten, 4% eine Fehloder Totgeburt. Die letztere war signifikant hoher bei den Patientinnen, die Antiepileptica erhielten. In dieser Serie waren 63 von 638 Lebendgeburten (9.9%) miRbildet, 55 (1 1.5%) stammten von therapier-ten Muttern, 3 (2,3)%) von nicht therapierten Muttern. Die Haufigkeit fetaler Fehlbildungen bei therapierten war 5mal hoher als bei nicht therapierten Muttern. Lippen- und/oder Gaumenspalte und MiRbildungen im kardiovaskularen Bereich wurden haufig bei Kindern therapierter Mutter gefunden. Die allgemeinen Hintergrundsfaktoren, die einen teratogenen EinfluR auf Schwangere mit Epilepsie ausuben konnten, wurden untersucht und die mogliche Toxicitat der Antiepileptica auf den Fetus analysiert. In diesen Untersuchungen sollte berucksichtigt werden, ob der Patient fokale epileptische Anfalle hat, o b e r selbst eine MiDbildung hat oder ob fruhere Schwangerschaften abnorm endeten. Die Haufigkeit der fetalen Fehlbildungen war am groRten (12.7%) bei therapiertenPatienten, die epileptische Anfalle wahrend der Schwangerschaft bekamen. Aufgrund dieser Resultate wird angenommen, daR die Kombination von mehr als 3 Medikamenten und eine tagliche Dosierung oberhalb eines Grenzwertes wahrscheinlich zu fehlgebildeten Kindern fuhren.

Spiral vortices in boundary layer transition regime on a rotating disk

Abstract: Behavior of spiral vortices on a disk rotating in still fluid is studied theoretically and experimentally in detail. A linear stability analysis, in which effects of streamline curvature and Coriolis force are considered, gives a critical Reynolds number at the onset of instability close to the one measured here by using a hot wire probe. Gradient of the vortex axis is determined under a condition of the maximum amplification. Flow patterns in the transition regime are experimentally visualized. The results show that the number of the spiral vortices is 31 or 32 as mean value and the gradient of the vortex axis decreases from 14° to 7° as the local Reynolds number is increased.

The short-range structure of alkali disilicate glasses by pulsed neutron total scattering

Abstract: Time-of-flight total neutron scattering experiments using pulsed neutrons with short wavelength produced by an electron linear accelerator have been carried out to measure the structure factors of SiO2 and M2O · 2 SiO2 (M = Li, Na and Li0.63Na0.37) glasses over a wide range of the scattering vector up to Q (=4π sin θ/λ) ∼480 nm−1. The Placzek correction has been considered up to the second order in the energy transfer. The Fourier transform of the structure factors yield the pair distribution functions highly resolved in real space, from which the stretching of the SiO and OO atomic distances and the number of bridging and non-bridging oxygen atoms in the alkali disilicate glass have been obtained.

Carbide reactions (M3C→M7C3→M23C6→M6C) during tempering of rapidly solidified high carbon Cr-W and Cr-Mo steels

Abstract: Carbide transformations of M3C → M7C3 → M23C6 → M6C and crystallographic relationships among these carbides were examined by transmission electron microscopy. Two kinds of high carbon-chromium steels containing tungsten or molybdenum were quenched rapidly from the melts and tempered at temperatures up to 700°C. By tempering at 600°C, M7C3 carbides nucleated mostly on cementite/ferrite interfaces and grew inward the cementite byin- situ transformation.In-situ transformations from M7C3 to M23C6 and from M23C6 to M6C were also found in these alloy steels during tempering at higher temperatures. Mutual relationships of crystal orientations among M3C, M7C3, M23C6 and M6C were decided as follows: {fx739-01}.

Specific perforation of muscle cell membranes with preserved SR functions by saponin treatment.

Abstract: The effects of saponin on Xenopus and frog skeletal muscle fibres were examined. The twitch of Xenopus single fibres was first potentiated slightly and then irreversibly abolished by 5-10 microgram/ml of saponin. Treatment with saponin at 5-10 microgram/ml or higher concentrations for 30 min resulted in perforation of the muscle cell membrane, indicated by the following evidence. (i) Fibres became responsive to contractile activating solutions with a pCa-tension relationship similar to that of mechanically skinned fibres. (ii) Removal and re-introduction of MgATP became effective in bringing fibres into rigor and the relaxed state, respectively. (iii) After the saponin treatment large contractions due to Ca release from the SR could be elicited by substitution of Cl for methanesulphonate in the medium. (iv) The treatment decreased the optical path length across the fibre, indicating loss of soluble proteins. (v) The lattice spacing of myofilaments was wider after the treatment as in mechanically skinned fibres. Contractile response of mechanically skinned fibres and their SR responses such as Ca uptake, Ca-induced Ca release and Cl-induced Ca release were not affected by treatment with 50 microgram/ml saponin for 30 min, while 150 microgram/ml or higher concentrations severely impaired by the SR functions. It is possible, therefore, to make chemically skinned skeletal muscle fibres in which the functions of the SR are preserved by applying 10-50 microgram/ml saponin.

Studies of the perpendicular magnetization mode in Co-Cr sputtered films

Abstract: The extremely high resolution properties in a perpendicular magnetic recording system were studied with a recently developed Co-Cr film medium. Bitter technique was used to observe magnetization distribution in the medium, and the transition of magnetization was directly observed on the top and the bottom surfaces of the film. It was proved that an ideal perpendicular magnetization mode, having a very narrow transition width, takes place even in a high recording density over 40 kBPI. From the angular variation of H c and the micro-structure of the Co-Cr film, it was concluded that the high recording resolution of the film results from the fine columnar particles which show the rotational mechanism of magnetization reversal accompanied by a perpendicular magnetocrystalline anisotropy. The Co-Cr film was also found to be superior in perpendicular anisotropy to any other Co-M films studied here in.

Surfaces of revolution with prescribed mean curvature

Abstract: In this paper we study a surface of revolution in the Euclidean three space Λ. The generating curve of the surface satisfies a nonlinear differential equation which describes the mean curvature. The purpose of this note is to solve the differential equation by an elementary method. Solutions are represented explicitly by generalized FresnePs integrals which involve the mean curvature. Therefore, for a given continuous function H(s), we can construct a 3-parameter family of surfaces of revolution admitting H(s) as the mean curvature. We shall remark that these computations are different from the one in Delaunay [1]. About 140 years ago, he solved the differential equation under the constancy of the mean curvature and gave a method of geometric constructions for such surfaces. For the proof, he first obtains a solution of an evolute of the generating curve. By making use of this solution, he found a representation formula of the generating curve. Therefore these solutions hold only on some intervals on which the evolute can be defined. It seems not to be simple to obtain a global solution from his method. Our calculations will easily find global solutions and the corollary of the main theorem of this note describes all complete surfaces of revolution with constant mean curvature. During this research I stayed in Kδln and received many nice advices from Professors Peter Dombrowski and Helmut Reckziegel. By their suggestions, my original computations could be simplified and generalized. And also I shall mention that Reckziegel got interested in drawing graphs of these generating curves by making use of the computer and obtained many beautiful pictures. He permitted me with favor to include some of the graphs by his programming in this paper. The author wishes to express his deep gratitude to both of them for helpful

Conjugate maps and duality in multiobjective optimization

Abstract: This paper considers duality in convex vector optimization. A vector optimization problem requires one to find all the efficient points of the attainable value set for given multiple objective functions. Embedding the primal problem into a family of perturbed problems enables one to define a dual problem in terms of the conjugate map of the perturbed objective function. Every solution of the stable primal problem is associated with a certain solution of the dual problem, which is characterized as a subgradient of the perturbed efficient value map. This pair of solutions also provides a saddle point of the Lagrangian map.

Correlation between CT findings and subsequent development of cerebral infarction due to vasospasm in subarachnoid haemorrhage.

Abstract: We have studied the correlations between computed tomograms (CT), clinical severity at the time of onset, and subsequent development of cerebral infarction due to vasospasm in 32 cases with subarachnoid haemorrhage secondary to rupture of cerebral aneurysms. It was found that the clinical severity could be judged by CT as shown by the amount of blood in subarachnoid space. Furthermore, it was possible to predict the subsequent occurrence of cerebral infarction by sequential findings of CT. A Hounsfield number of the high density area over 60 showed good correlation with the development of cerebral infarction.

Sensitivity to salts and organic compounds of soil bacteria isolated on diluted media

Abstract: Bacteria were isolated from soil on a 100-fold dilution of nutrient broth agar, a 10-fold dilution of alubumin yeast extract agar, or agar without additional nutrient. Their growth was severely suppressed by full strength nutrient broth but well supported by a 100-fold dilution of nutrient broth and these organisms were proposed to be called dilute nutrient broth (DNB) organisms.One percent each of peptone and meat extract, and 1% or 2% casamino acids severely suppressed growth of most of them. Glycine, arginine, serine, or lysine (10mM), yeast extract (0.1%), nicotinic acid or thiamine (20μg/ml), and sodium succinate (20-50mM) inhibited growth of many organisms though sensitivity of each organism to organic compounds was of a great variety. They were also highly sensitive to NaCl and KCl. Growth inhibition of some isolates by serine was recovered by coexisting threonine, alanine, or leucine and valine. Inhibitive effect of serine was also influenced by NaCl, KCl, CaCl2, or MgCl2.

Effect of Molybdenum on the Anodic Behavior of Amorphous Fe‐Cr‐Mo‐B Alloys in Hydrochloric Acid

Abstract: The addition of a small amount of molybdenum to amorphous Fe‐Cr‐B alloys improves the corrosion resistance in hydrochloric acid. In particular, amorphous alloys containing 5 atomic percent or more molybdenum passivate spontaneously even in , showing no pitting by anodic polarization. However, an excess addition of molybdenum lowers the corrosion potential and raises the anodic current density in the passive region. This dual function of molybdenum was investigated with XPS and electrochemical methods. In the active region, an increase in the molybdenum content of the alloys decreases the anodic current density by the formation of a surface film containing large amounts of chromium and some molybdenum. The addition of molybdenum assists the formation of the passive hydrated chromium oxyhydroxide film. However, a passive film of molybdenum oxyhydroxide is unstable in comparison with the passive hydrated chromium oxyhydroxide film even at lower potentials in the passive region, and molybdenum suffers transpassive dissolution at higher potentials in the passive region. An excess of molybdenum results in a passive film whose content of molybdenum in an unstable valence state is high. Consequently, the addition of molybdenum is significantly effective in increasing the corrosion resistance, particularly in aggressive hydrochloric acid, but the lower the molybdenum content of the passive film the better is the protective quality of the film.

Sink-float separators using permanent magnets and water based magnetic fluid

Abstract: The development of sink-float separators for materials of different densities, which utilize the levitation force of magnetic fluid, have been recently reported. The system usually consists of an electromagnet, separation cell, equipment for recovery of magnetic fluid smeared on the separated products, and controlling system. This paper describes and discusses the construction of sink-float separators using permanent magnets and provides test results for artificial mixtures of nonferrous metals. Ferrite magnet and rare-earth cobalt magnet were used as magnetic field generators in two separators. One for separating aluminum from other nonmagnetic metals, and the other to separate copper, zinc and lead from each other. A series of tests were performed on samples of 6 to 30 mm size, and it was found that the separators operated as expected. The separation of finer metals, however, proved difficult due to the attractive force which acts between nonmagnetic bodies immersed in magnetic fluid in a magnetic field. The chemical process to recover the magnetic fluid from smeared separation products is also proposed.