Showing papers by "University of Tokyo published in 1969"
837 citations
TL;DR: As is well known, the memorable discovery of Galvani (1791) was followed by the development of two new fields of science, electrochemistry and electrophysiology, which resulted in a marked progress of physiological and morphological studies which were intentionally or unintentionally concerned with the mechanism of the link between excitation at the surface membrane, and the contractile process.
Abstract: As is well known, the memorable discovery of Galvani (1791) was followed by the development of two new fields of science, electrochemistry and electrophysiology. During the course of this development, the most remarkable feature of the original finding, i.e. ‘contraction of muscle induced by a piece of metal’, gradually came to be ignored. As a consequence, the simple question as to how electrical stimulation might induce muscle contraction was left unanswered until the middle of this century, when several physiologists became aware of the crucial nature of the problem and tried to attack it from various directions. This resulted in a marked progress of physiological and morphological studies which were intentionally or unintentionally concerned with the mechanism of the link between excitation, that is the electrical phenomenon at the surface membrane, and the contractile process.
734 citations
TL;DR: In this article, a dynamical theory of X-ray and electron diffraction for a distorted crystal which has been briefly explained elsewhere (Acta cryst. 15 (1962) 1311) is presented in more detail.
Abstract: A dynamical theory of X-ray and electron diffraction for a distorted crystal which has been briefly explained elsewhere (Acta cryst. 15 (1962) 1311) is presented in more detail. The fundamental equations for both the X-ray and electron cases are deduced from the Maxwell or the Schrodinger equations, respectively, inside crystalline media which may contain distortions. A method of solution of the equations using the Riemann function is given together with the following general results; (1) the intensities and integrated intensities, with respect to the incident angle, of the transmitted and diffracted rays at a point on the exit surface are given by integrals over the entrance surface, (2) a theoretical basis for the column approximation in the electron case is provided, (3) the intensities of the X-ray projection topographs (traverse pattern) is not dependent upon the type of the incident waves but upon the total intensity to which the crystal is exposed. The limit of the applicability of the present theo...
628 citations
557 citations
TL;DR: Factors indicate that the pre-illumination of pigment system II changes the efficiency of excitation transfer between chlorophyll a molecules and the fluorescence yields at liquid nitrogen temperature.
548 citations
TL;DR: In this paper, the first success in using carbon dioxide as a direct starting material for synthesizing high polymers was reported, which was confirmed with the aid of IR, NMR and elemental analysis.
Abstract: Attempts to copolymerize carbon dioxide with epoxide led us to the first success in using carbon dioxide as a direct starting material for synthesizing high polymers. Some organometallic catalyst systems were found to catalyze the alternate copolymerization of carbon dioxide and epoxide, resulting in the formation of polycarbonates, the structures of which were confirmed with the aid of IR, NMR and elemental analysis. Diethylzinc-water system produced a methanol insoluble aliphatic polycarbonate of much higher molecular weight than that produced by polycondensation. Thermal properties of the methanol insoluble polycarbonate were studied by differential thermal analysis and thermogravimetric analysis.
521 citations
TL;DR: The neural substance has been renamed gonad stimulating substance (GSS), and the second substance, produced in the ovary, is meiosis inducing substance (MIS), which seems to be non-species specific among starfishes7.
Abstract: INVESTIGATIONS of the mechanism of starfish spawning induced by injection of a water extract of radial nerves have shown that an active polypeptide acts on the ovary and induces the production of a second substance which is, in the true sense, a meiosis inducing factor as well as a spawning inducing factor1–7. The neural substance has therefore been renamed gonad stimulating substance (GSS), and the second substance, produced in the ovary, is meiosis inducing substance (MIS)5,7. Isolated ovarian fragments immersed in seawater containing MIS discharge their eggs4,5,7, while isolated oocytes with germinal vesicles treated with MIS mature4–7. The production of MIS by GSS has been demonstrated in isolated ovarian fragments of seven species of starfish, and it seems to be non-species specific among starfishes7. MIS is heat stable (100° C, 30 min) and is not a peptide5,6.
446 citations
TL;DR: The facts indicate that Mg2+ controls the distribution of excitation energy between the two pigment systems and that the control consists mainly in change in rate ofexcitation transfer from the bulk chlorophyll a molecules in pigment system II to those in pigmentSystem I.
350 citations
TL;DR: The studies of the healing process of the produced ulcer and the usefulness for the assay method of the curative drugs of gastric ulcer are dealt with.
327 citations
316 citations
TL;DR: The utricular-ocular reflex reacted from very low to very high frequencies, as high as 1600 cps, in comparison, the cupulo-ocular Reflex arc did not respond well to high frequencies.
Abstract: Single utricular nerves were electrically stimulated in the cat. The induced eye movements were almost pure rotation in both eyes. In addition to rotation, there were upward shifts in the ipsilateral eye and downward shifts in the contralateral eye. Slight contralateral horizontal shifts occurred in both eyes. Tension increases in extraocular muscles were strongest in the ipsilateral superior oblique and contralateral inferior oblique. They were weaker in the ipsilateral superior rectus and contralateral inferior rectus, and were weakest in the ipsilateral medial rectus and contralateral lateral rectus muscles. The tension increase in the contralateral inferior oblique and the lateral rectus was studied by changing the frequency of stimulation. The utricular-ocular reflex reacted from very low to very high frequencies, as high as 1600 cps. In comparison, the cupulo-ocular reflex arc did not respond well to high frequencies. The temporal summation in the vestibulo-ocular reflexes appeared different between...
TL;DR: There seemed to be a large seasonal variation in boreal zooplankton due to great fluctuations of environmental conditions, especially the amount of food available; in tropical species the range was small because of environmental uniformity.
Abstract: Wet and dry weight, total carbon, nitrogen, hydrogen, and ash contents were determined on 33 species of zooplankton distributed predominantly in the open sea region of the North Pacific. Sampling covered the waters from 44°N to the equator. Average percentage of dry weight to wet weight was about 19% of all samples from the whole area. Percentage dry weight of carbon in copepods was on an average 51.5%. The highest value, 66.6%, was obtained in eggs of the copepod Pareuchaeta sarsi. Mixed zooplankton was assumed to contain carbon comprising about 35 to 45% of the dry weight. Carbon contained in the zooplankton biomass existing in the upper 200 m in the western parts of the northern North Pacific and Bering Sea during spring and summer was estimated to range from 20 to 85 mg C/m3. Nitrogen content varied considerably with localities. Average ratio of carbon to nitrogen was 8.5 in subarctic copepods, and 4.1 in subtropic-tropic copepods. This ratio also varied with season. In the copepod Calanus cristatus the ratio was highest (10.0) in May, immediately after the spring bloom of phytoplankton, when the animals contained much fat. The ratio fell to 5.1 in December. There seemed to be a large seasonal variation in boreal zooplankton due to great fluctuations of environmental conditions, especially the amount of food available; in tropical species the range was small because of environmental uniformity. Average hydrogen content was about 6 to 10%. The percentage of ash to dry weight amounted to 39.3% in pteropods and 3.4% in copepods.
TL;DR: l-Methyladenine brings about spawning as well as oocyte maturation in vitro in starfish, Marthasterias glacialis, Astropecten aurantiacus and Ceramaster placenta and appears to act only on the full-grown oocytes.
TL;DR: Two anti-H(O) phytohemagglutinins have been separated by (NH4)2SO4 fractionation of extracts of Ulex europeus seeds and one was found to be inhibited by L-fucose and the other was inhibited most by di-N-acetylchitobiose.
TL;DR: It is concluded that nocturnal sleep is a potent stimulator for the development of human growth hormone (HGH) and blood sugar and the secretion of plasma HGH was inhibited during paradoxical sleep.
Abstract: EEG, pulse rate, respiration and eye movement were polygraphically recorded throughout the night in 10 normal adult male subjects. Blood was collected every 20 min throughout the night by means of an indwelling venous catheter without disturbing the natural course of sleep. Human growth hormone (HGH) and blood sugar were measured in these plasma samples. Depth of sleep was classified into 5 stages by EEG. A marked elevation of plasma HGH was constantly observed coincident with the onset of sleep. Following the initial large HGH peak, additional peaks of HGH, with a decrease in the size of subsequent peaks, were observed. Shifting the time of the onset of sleep by 3 hr before or after the usual bedtime did not change the elevation of plasma HGH coincident with the onset of sleep. When a state of full wakefulness was maintained at night, plasma HGH did not rise. The secretion of plasma HGH was inhibited during paradoxical sleep. It is concluded that nocturnal sleep is a potent stimulator for the se...
TL;DR: In this article, the discrepancy between the r a o and r z structures of acrolein reported in a previous study has been removed by taking into account small isotopic differences in the distances among the carbon and oxygen atoms.
TL;DR: A theoretical study was made on the dynamic behavior of a single‐vessel continuous fermentation subject to a growth inhibition at, high concentration of the rate limiting substrate, which showed three steady states to exist; namely, a “washout”; state, a nontrivial stable state, and an unstable state.
Abstract: A theoretical study was made on the dynamic behavior of a single-vessel continuous fermentation subject to a growth inhibition at, high concentration of the rate limiting substrate. Phase plane plotting and stability analysis showed three steady states to exist; namely, a “washout”; state, a nontrivial stable state, and an unstable state. Whether the system attains a nontrivial steady state or is to be washed-out depends upon the initial values of the cell and/or substrate concentration(s). Since this property is a characteristic feature of the present system, an experimental procedure was suggested to insure a stable operation in practice.
TL;DR: Experiments in vitro as well as in vivo show that DGLP-I can stimulate the release ofDiglyceride from the insect fat body and efficiently take up the released diglyceride, whereas DGLp-II appears to lack such a physiological function.
01 Jan 1969
TL;DR: In this article, an experimental study of the structure and the blow-off mechanism of the laminar counterflow diffusion flame established in the forward stagnation region of a porous cylinder was made.
Abstract: An experimental study has been made of the structure and the blow-off mechanism of the laminar counterflow diffusion flame established in the forward stagnation region of a porous cylinder. Concentration profiles of the stable species were determined using a microprobe sampling technique and gas-chromatographic analysis for hydrocarbon flames at atmospheric pressure. The over-all structure of the flame was examined by optical interferometry. Experimental results show that there are always various intermediate hydrocarbons and some oxygen on the fuel side of the flame. Hydrogen and carbon monoxide, which are the intermediate products, exist on both the fuel and air sides of the flame. The maximum concentrations of hydrogen and various intermediate hydrocarbons are found near the stagnation point of the counterflow. Although the flame approaches the cylinder surface when the fuel-ejection rate is decreased or the stagnation velocity gradient is increased, the differences in the concentration profiles for the case of a low fuel-ejection rate and for the case of a large stagnation velocity gradient are remarkable. It has been confirmed that critical blow-off of the flame is due to chemical limitations on the combustion rate in the flame zone and is clearly distinguished from blow-off caused by thermal quenching of the flame.
TL;DR: Plasma DS levels were suppressed up to 21% of the control values after administration of dexamethasone, 2 mg daily for 3 days, and chronic treatment with prednisolone lowered plasma DS levels to near zero values.
Abstract: Dehydroepiandrosterone sulfate (DS) in human peiipheral plasma was estimated under various experimental conditions. In both sexes base-line plasma levels of DS were found to be low before puberty, to reach their maximum between the late stage of the second decade and the early period of the third decade, and to decline with advancing age. The values were higher in young male than those in young female subjects. ACTH administration caused a definite increase in plasma DS as compared to the control values, and there was no difference between young and aged groups in per cent increase in plasma DS values after ACTH stimulation. Plasma DS levels were suppressed up to 21% of the control values after administration of dexamethasone, 2 mg daily for 3 days, and chronic treatment with prednisolone lowered plasma DS levels to near zero values. HCG produced no significant effect on plasma DS levels. Concentrations of plasma DS in 20 patients with hypoadrenocorticism were distinctly low in all cases. In 9 of...
TL;DR: The time response of the ‘fluorescence lowering’ differed from that of the light-scattering change in the chloroplasts, thus indicating that the “fluorescence lowered” was not caused by the conformational change corresponding to the light, scattering change of the chlorplasts.
TL;DR: Diet limitation which resulted in marked body weight loss in young rats had little influence on both the formation and the maintenance of the carrageenin granuloma.
TL;DR: In this paper, it was shown that a relation between the distribution of grain size and the spectrum of coercivities exists, not only for prepared samples, but for rocks as well.
Abstract: Summary
Most tests of the magnetic stability of a rock provide only a crude evaluation. A better estimation could be obtained by measuring the spectrum of coercivities possessed by a rock; a simple means of obtaining the coercivity spectrum is presented.
It is also shown that a relation between the distribution of grain size and the spectrum of coercivities exists, not only for prepared samples, but for rocks as well. An evaluation of the sizes of the opaque grains effectively controlling the magnetic properties must not only take account of initial crystallization processes but must include consideration of post-consolidation, high- and low-temperature oxidation modifications. The development of effective grain size is discussed.
Results of this study have provided additional insight into the relation of the shape of a Js-T curve and the opaque mineralogy.
TL;DR: In this article, a series of high pressure transformations are found to occur in the order of the packing sequence along the hexagonal c axis (or cubic 111 axis) of ( a b ), (a b a b c b c c a c ), ( b c a b a c b ) and ( b b c ) with increasing pressure.
Abstract: Phase stability relations among four hexagonal perovskite-like structures as well as the cubic perovskite structure have been studied for several oxides (BaMnO 3 and SrMnO 3 ) and fluorides (CsMnF 3 , RbNiF 3 and TlNiF 3 ) at high pressure. A series of high pressure transformations are found to occur in the order of the packing sequence along the hexagonal c axis (or cubic 111 axis) of ( a b ), ( a b a b c b c a c ), ( a b a c ), ( a b c a c b ) and ( a b c ) with increasing pressure. This order is corresponding with the increasing order of the proportion of the cubic close-packed layers in the hexagonal close-packed structure. It is suggested that the tolerance factor of the perovskite structure and the Coulomb repulsive force play an important role in determining the crystal structure and its order in the series of phase transformations at high pressure.
TL;DR: In this paper, the Fulde-Ferrel model was used to investigate the properties of the phase transitions from superconducting states to the other states, where the phase transition from a superconductor to a non-superconductor was studied.
Abstract: The Fulde-Ferrel model, in which a molecular field is acting on the spins of the con duction electrons responsible for supercond,uctivity, is investigated. The superconducting state, that is described by the condensate wave function oscillating in space and gives rise to a gapless energy spectrum, is shown to be the ground or equilibrium state for some values of the pairing interaction and the molecular field. Thermodynamic properties of such gapless superconducting. states are investigated extensively. Special attention is paid on the properties of the phase transitions from such superconducting states to the other states.
TL;DR: DNA must react with 2-mercaptoethanol since the T m of DNA after the reaction is decreased, as shown by the reaction with bleomycin A 2.
TL;DR: In this article, a model was proposed to analyze the dissolution phenomena involving simultaneous phase changes and its experimental demonstration was done with p-hydroxybenzoic acid and phenobarbital which change to the respective hydrates during dissolution.
Abstract: A model was proposed to analyze the dissolution phenomena involving simultaneous phase changes and its experimental demonstration was done with p-hydroxybenzoic acid and phenobarbital which change to the respective hydrates during dissolution. The mathematical expression for the dissolution according to this model was given by equation (3) or (4). Conbining the rotating disk method with the above equations, it was possible to determine the rate constant of crystallization process, kr, and the saturated concentration of anhydrate, CSA, which are hardly obtainable by other usual methods. At the same time, the rate constant of transport process, kt, and the saturated concentration of hydrate, CSH, were obtained. Analyzing the values of kt, kr, CSA, and CSH obtained at various temperatures, the activation energies of transport and crystallization process and the thermodynamic functions of the transition from anhydrate were determined, being reasonable compared with the past data reported on organic medicinals. The transition temperatures obtained from the intersections of the van't Hoff plots regarding anhydrate and hydrate were 84°for p-hydroxybenzoic acid and 37°for phenobarbital. In the case of p-hydroxybenzoic acid, (CSA-CSH) increased with temperature in the experimental temperature region.
TL;DR: E(t) is calculated of areflexive left ventricles of dogs under various v(o) controlled by occlusion of the vena cava and has ap-proximately unchanged time course and magnitude in a wide range of v(O).
Abstract: A variable, e(t)=p(t)/v(t), is proposed for formulating the ventricular pumping of blood, as a concept of the reciprocal of ventricular compliance, where t=time, p(t)=time course of the intraventricular pressure and v(t)=that of the intraventricular volume. For actual computation, e(t)=p(t)/{v(o)-∫toi(t)dt} where v(o)=v(t) at t=o or enddiastolic volume and i(t)=aortic blood flow. v(o)=(1-ρ)-1•vs, where ρ=residual volume ratio measured by a thermodilution method and vs=stroke volume or integral of i(t) in the cardiac cycle. e(t) is calculated of areflexive left ventricles of dogs under various v(o) controlled by occlusion of the vena cava. In spite of conspicuous changes of p(t), i(t) and v(t), e(t) has ap-proximately unchanged time course and magnitude in a wide range of v(o). A model of ventricular pumping is presented with e(t).