Showing papers by "Hiroshima University published in 1976"
TL;DR: In this paper, two new glucosides, rebaudiosides A and B, were isolated from the leaves of Stevia rebaudiana and formulated as β-glucosyl ester.
228 citations
TL;DR: When a strand of the rabbit sinoatrial node tissue was shortened by ligation, the spatial decay of electrotonic potential decreased and the input impedance increased, and in a piece of the tissue apparently uniform current spread was obtained.
Abstract: When a strand of the rabbit sinoatrial node tissue was shortened by ligation, the spatial decay of electrotonic potential decreased and the input impedance increased. In a piece of the tissue 0.2-0.3 mm in diameter apparently uniform current spread was obtained. Action potentials recorded from three different sites in this small piece occurred simultaneously and were superimposable. In voltage clamp experiments using the double microelectrode method, the membrane potential was usually held at -30 to -40 mV, where no net current flowed. When membrane potential was suddenly changed from the holding potential, the sign and the time course of the ionic current varied with membrane potential. Hyperpolarization gave an inward current which increased with time. Depolarization gave a transient inward current followed by sustained outward current, and repolarization gave an outward current tail which exponentially subsided with a time constant of 0.37 s. The membrane time constant was 12.0 ms. When the specific membrane capacitance was assumed to be 1 muF/cm2, the specific membrane resistance at the resting potential was 12 Komega cm2. The peak of the transient inward current on depolarization was 1.3 X 10(-5) A/cm2.
223 citations
TL;DR: In this paper, the shape and orientation of the strain ellipsoid were determined by using deformed elliptical objects as strain markers, assuming that the objects are of truly ellipseidal shape with random orientation in the undeformed state, and that they deform homogeneously with their matrix.
178 citations
TL;DR: A brief review of stochastic models on system-reliability lists selected references on system reliability models using stochastics processes such as Markov chains, Markov processes, renewal processes, and semi-Markov (Markov renewal) processes.
Abstract: A brief review of stochastic models on system-reliability lists selected references on system reliability models using stochastic processes such as Markov chains, Markov processes, renewal processes, and semi-Markov (Markov renewal) processes.
148 citations
TL;DR: In this article, the shrinkage in dehydration of root vegetables such as carrots, potatoes, sweet potatoes and radishes was investigated, and three drying models were postulated for the formulation of the relation between the changes of the surface area and the moisture contents.
Abstract: The shrinkage in dehydration of root vegetables such as carrots, potatoes, sweet potatoes and radishes was investigated. The samples were dried in flowing hot air. The surface areas were measured by photographing the samples. Three drying models were postulated for the formulation of the relation between the changes of the surface area and the moisture contents. The uniform drying model, which in the case of drying is that the shrinkage in volume equals the volume of water lost by the evaporation, agreed with the measured values during the early stages of the drying. The core drying model by assuming the formation of the dried layer at outer side of material was better in agreement with the experimental results. The semicore drying model, which is the intermediate model between the uniform and the core drying model, and the empirical equations of the shrinkage were also considered.
142 citations
TL;DR: Findings indicate that the outward current tail in the S-A node cell is attributable to a single component of K current (pacemaker current component), which is mainly responsible for the slow diastolic depolarization.
Abstract: Voltage clamp experiments were conducted in the rabbit sinoatrial node (S-A node) using the double microelectrode technique. When the membrane was repolarized to the resting potential after depolarizing test pulses, the outward current slowly decayed to the steady level (outward current tail). The magnitude of the outward current tail was a sigmoid function of the amplitude of the preceding depolarization. The degree of activation of this current varied from 0 at about − 50 mV to 1 at about +20 mV. The time course of the current change was a simple exponential and was independent of the preceding depolarization. The reciprocal time constant appeared to be a U-shaped function of the membrane potential with a minimum value of about 3 s−1 at −40 mV. The instantaneous current voltage relation was an inward-going rectifier, but showed no detectable negative slope. The reversal potential, obtained between 10 and 50 mM [K]
o
, decreased with a slope of 58 mV for a 10-fold increase in [K]
o
. These findings indicate that the outward current tail in the S-A node cell is attributable to a single component of K current (pacemaker current component). The pacemaker current component is mainly responsible for the slow diastolic depolarization.
120 citations
TL;DR: In this article, new correlations have been proposed for estimation of gas phase holdup, characteristic velocity, interfacial area for mass transfer and mean bubble size of bubble swarms under dispersed and fluidized operation of bubble columns employing single and multi-orifice distributors.
Abstract: New correlations have been proposed for estimation of gas phase holdup, characteristic velocity, interfacial area for mass transfer and mean bubble size of bubble swarms under dispersed and fluidized operation of bubble columns employing single — and multi-orifice distributors. The analysis of results include available literature data of other investigators.
117 citations
TL;DR: In this paper, it was shown that with increasing γ i of the dielectric panel material the firing voltage of an ac gas discharge display panel decreased, under the condition that the secondary electrons became greater than unity and unstable self-sustained emission was observed.
Abstract: From the measurement of the ion-induced secondary electron emission yield γ i it was shown that with increasing γ i of the dielectric panel material the firing voltage of an ac gas discharge display panel decreased. The measurement of the energy distributflon of the secondary electrons showed that the dielectric material with higher γ i has lower most-probable energy (MPE), and half-width (HW) values. The energy distribution introduced by Stolz in the ease of secondary electrons emitted from a metal was applied to the dielectric panel material and solved by using a computer. From this result, it was shown that the lower the electron affinity of the dielectric panel material, the higher is the γ i . Under the condition when γ i became greater than unity, unstable self-sustained emission was observed even though the primary ion beam was cut off.
113 citations
TL;DR: The results suggested that innervation of monoaminergic neurons in the brain progressed with increasing age, that projections of both NE and 5-HT neurons were relatively high into hypothalamus and limbic-striatum and that DA neuron projections concentrated at striatum.
107 citations
TL;DR: In this paper, the authors investigated the mechanism of cooking rice and concluded that the cooking process comprises two mechanisms; at temperatures below 110°C the cooking rate is limited by the reaction rate of rice components with water; and at temperatures above 120°C it is limited due to the rate of diffusion of water through the cooked layer toward the interface of uncooked core where the reaction occurs.
Abstract: The mechanism of cooking rice was investigated in this study. The rheological method using the parallel plate plastometer was adopted for measurement of the degree of cooking. The range of temperatures measured ran from 75–150°C. Experimental results showed that cooking rate followed the equation of a first order chemical reaction. We designated the proportional constant as the cooking rate constant, but the slope of Arrhenius plots of the cooking rate constants changed around 110°C. The activation energy of cooking at temperatures below 110°C and above 110°C was about 19,000 and 8,800 cal/mol respectively. The influences of water soaking time before cooking were also studied. We concluded that the cooking process comprises two mechanisms; at temperatures below 110°C the cooking rate is limited by the reaction rate of rice components with water; and at temperatures above 110°C it is limited by the rate of diffusion of water through the cooked layer toward the interface of uncooked core where the reaction occurs. The reaction rate constant and the diffusion coefficient of water were calculated by assuming the core model or shell-type model.
102 citations
TL;DR: Prawns fed diets supplemented with 4% sardine oil or 4% clam oil, rich in ω3 PUFA had a high moulting rate, the best growth and a high level of ω 3 polyunsaturated fatty acids, indicating that regulation of palmitic acid synthesis could be exercised through desaturation and chain elongation.
TL;DR: A phenanthrene-assimilating bacterium which belongs to the genus Aeromonas was isolated from soil and it was suggested that the aeromonas sp.
Abstract: A phenanthrene-assimilating bacterium which belongs to the genus Aeromonas was isolated from soil. The cells which adapted to phenanthrene required a growth lag time on a naphthalene medium. The cells oxidized l-hydroxy-2-naphthoate (1H2NA), 2-carboxybenzaldehyde (2CBAL), o-phthalate (OPA) and protocatechuate (PCA) but did not oxidize salicylaldehyde (SAL), salicylate (SA) and catechol (CAT) which are intermediates in naphthalene catabolism. Using the cell-free extract, the same results were obtained in oxidative capacity. The intact cells metabolized 1H2NA and 2CBAL without the lag time, giving 2CBAL and PCA, respectively. The ammonium sulfate-treated extract prepared from the cells grown in phenanthrene medium, converted 1H2NA to 2CBAL and 2CBAL to OPA. It was suggested that the Aeromonas sp. degraded phenanthrene through OPA.
TL;DR: In this article, a single viscous layer embedded in a less viscous medium is analyzed by use of the finite-element method and the results are correlated with data on natural folds of Sambagawa metamorphic rocks.
TL;DR: In this paper, the relaxation of a relativistic electron beam in plasma with random density inhomogeneities is studied, and the model attributing the formation of random density in the beam to the modulational instability of the Langmuir condensate produced by the beam plasma interaction is used to estimate self-consistently the level of inhomalities.
Abstract: The relaxation of kinetically unstable relativistic electron beam in plasma with random density inhomogeneities is studied. Their effect is treated as angular diffusion of resonantly excited Langmuir waves in the wavenumber space. Formulas effective for obtaining the beam energy deposition rate and the Langmuir-wave fluctuation spectrum are presented. The result shows a strong reduction of the energy relaxation rate due to diffusion of Langmuir waves from linearly unstable region to the region where they are damped by the beam itself. The model attributing the formation of random density inhomogeneities to the modulational instability of the Langmuir condensate produced by the beam plasma interaction is used to estimate self-consistently the level of inhomogeneities.
TL;DR: The 3beta-hydroxysteroid oxidase produced by Streptomyces violascens was purified from the culture broth by procedures including batch-wise treatment on DEAE-cellulose, ammonium sulfate fraction, gel filtration on Sephadex G-75, and column chromatography onDEAE- cellulose and showed a high substrate specificity for 3 beta-Hydroxysteroids and the activity was not influenced by the addition of external electron donors.
Abstract: The 3beta-hydroxysteroid oxidase produced by Streptomyces violascens was purified from the culture broth by procedures including batch-wise treatment on DEAE-cellulose, ammonium sulfate fraction, gel filtration on Sephadex G-75, and column chromatography on DEAE-cellulose. The highly purified enzyme preparation exhibited no significant absorption maxima in the visible region other than a maximum at 280 nm. Optimum pH and temperature for the enzyme activity were approximately pH 7.5 and 50 degree, respectively. The Michaelis constant (Km) for cholesterol determined under two different experimental conditions were 4.5 and 6.7 X 10(-4) M. The enzymatic activity was remarkably inhibited by various metal salts such as FeC1(3), FeSO4, AgNO3, etc. On the other hand, neither EDTA nor Fe-chelating agents had any inhibitory effect on the enzymatic activity, while other metal-binding agents, KCN and NaN3, caused significant inhibition. The enzyme activity was inhibited almost completely by N-bromosuccinimide and iodine but not p-chloromercuribenzoate. The highly purified enzyme did not require any external electron acceptors other than oxygen. In addition, the activity was not influenced by the addition of external electron donors. The enzyme showed a high substrate specificity for 3beta-hydroxysteroids and the relative oxidation rates were 100 for cholesterol, 91 for 5alpha-cholestan-3beta-ol, 83 for pregn-5-en3beta-ol-one, 80 for androst-5-en-3beta-ol-17-one, 64 for 5alpha-androstan-3beta-ol-17-one, ect. The oxidation of cholesterol by the enzyme was remarkably inhibited by the addition of 5alpha-cholestan-3beta-ol, 5alpha-cholestan-3-one, 5beta-cholestan-3beta-ol, 5alpha-cholestane3beta, 5alpha-doil or 5alpha-lanosta-8, 24-den 3beta-ol. These findings indicate the present enzyme belongs to the class of 3beta-hydroxysteroid oxidase but some of its physical and enzymatic properties obviously differ from those of 3beta-hyroxysteroid oxidase of Brevibacterium.
TL;DR: The proposed methods are applied satisfactorily for determination of As(III) and As(V) in various types of water.
TL;DR: It is impossible to differentiate this organism provisionally classified as Vibrio anguillicida BRUUN and HEIBERG in the previous report from Vibria fischeri in terms of the above-mentioned two characters.
Abstract: The preceding papers(MUROGA et al., 1976 a, b)dealt with the biochemical characteristics, taxonomical status, physiological characters and pathogenicity of Vibrio sp. isolated from a new eel vibriosis.In this paper the effect of NaCl concentrations of cultrue media on the NaCl tolerance and on the flagellation of the vibrio were examined, and these two characters of the organism were reconsidered by way of comparison with those of Vibrio fischeri.The experimental results together with considerations are given as under.1) NaCl tolerance : The lower limit falled to 0.1% after consecutive culture in the media containing 0.3% NaCl. The upper limit, in contrast with this, raised to 6% in case of the media with 4% NaCl. The range of 0.1 to 6% is applicable to the NaCl tolerance range of this organism in view of these results.2) flagellation: Cells having more than one flagellum at one pole occurred in cultures grown on nutrient agar plate, of which the higher the NaCl concentration (0.5-4.5%), the higher the percent occurrence (0.22-20%). Cells, however, had one polar flagellum in cultures grown in nutrient broth except in the broth with extremely high concentration (4%) of NaCl. Accordingly it may be safely said that the flagellation of this organism is monotrichous.In conclusion it is impossible to differentiate this organism provisionally classified as Vibrio anguillicida BRUUN and HEIBERG in the previous report (MUROGA et al., 1976a) from Vibrio fischeri in terms of the above-mentioned two characters.
TL;DR: It is suggested that significant intraoperative increases in serum LH levels occur in males but not in females, and there were significant intra- and post-operative decreases in testosterone levels in male patients.
Abstract: Effects of surgical stress under the same general anesthesia (nitrous oxide, oxygen and halothane following induction with thiopental and succinylcholine chloride) on serum LH levels were studied in 18 postmenopausal females, 15 menstruating females and 17 males. In addition, serum FSH levels in female patients and testosterone levels in male patients were estimated. As controls without surgery and anesthesia, serum levels of LH, FSH and testosterone were estimated at identical time intervals to the experimental group in 15 normal postmenopausal females, 15 normal menstruating females and 10 normal males. In male patients, serum LH levels at 30 min and 1 hr after onset of anesthesia increased significantly over those of pre-anesthesia, while no significant intra-operative increase in LH levels was found in female patients. In male and female patients, the LH levels decreased slightly 5-6h and 2 days after onset of anesthesia, though the decreases were not statistically significant except in postmenopausal females. On the 7th postoperative day, the LH levels returned toward the baseline. In female patients, no significant intra-operative changes in FSH levels were found. In male patients, there were significant intra- and post-operative decreases in testosterone levels. In control subjects, no significant changes in serum levels of LH, FSH and testosterone were demonstrated. These observations suggest that significant intraoperative increases in serum LH levels occur in males but not in females.
TL;DR: Meyer et al. as discussed by the authors isolated six saponins from the leaves of Panax ginseng and formulated them as 20-O-β-glucopyranosyl-20 (S)-protopanaxatriol.
Abstract: From the leaves of Panax ginseng C. A. MEYER, six saponins I, II, III, IV, V, and VI were isolated. Saponins IV, V, and VI were proved to be identical, respectively with ginsenosides-Rg1, -Re, and-Rd, all of which have already been isolated from Ginseng roots. The high contents of these saponins in the leaves indicate significance of the leaves as the source of the dammarane-type saponins and their sapogenins. New saponins I, II, and III designated as ginsenosides-F1, -F2, and-F3 were established to be formulated as 20-O-β-glucopyranosyl-20 (S)-protopanaxatriol, 3, 20-di-O-β-glucopyranosyl-20 (S)-protopanaxadiol, and 20-O-(α-arabinopyranosyl-(1→6)-β-glucopyranosyl)-20 (S)-protopanaxatriol, respectively, on the basis of the enzymatic hydrolysis, mass spectra of their acetates, nuclear magnetic resonance, and chemical evidences.
TL;DR: Asymptotic expansions of the joint distributions of the latent roots of the Wishart matrix and multivariate F matrix are obtained for large degrees of freedom when the population latent roots have arbitrary multiplicity as mentioned in this paper.
TL;DR: A consistent chromosome abnormality of C‐G translocation, t(8;21)(q22;q22), was found in 15 acute myelocytic leukemia (AML) patients with low neutrophil alkaline phosphatase (N‐AP) activity and may offer additional evidence towards the possible relations between alkaline phosphate activity and C or G chromosome.
Abstract: A consistent chromosome abnormality of C-G translocation, t(8;21)(q22;q22), was found in 15 acute myelocytic leukemia (AML) patients with low neutrophil alkaline phosphatase (N-AP) activity Granulocytes of these patients also had specific morphologic abnormalities The bone marrow showed a tendency to relatively good maturation of leukemic cells for the disease AML Clinical courses of the patients were mild and median survival was longer than that of patients with normal or high N-AP activity (p = 0065, suggestive difference) Three out of six male patients with these type of AML had missing Y chromosome in addition to C-G translocation The results suggest that specific cytogenetic abnormality of C-G translocation would be significantly associated with AML Contrasting with low N-AP activity and the Philadelphia chromosome in chronic myelocytic leukemia, the findings in AML may offer additional evidence towards the possible relations between alkaline phosphatase activity and C or G chromosome
TL;DR: By comparing the nucleotide alignment from the juxtaposed 5S RNA secondary structures, a phylogenic tree of nineteen organisms was constructed and found that prokaryotic and eukaryotic 5S RNAs are quite similar to each other, except for a difference in a specific region.
Abstract: Based on the comparative analyses of the primary structure of 5S RNAs from 19 organisms, a secondary structure model of 5S RNA is proposed. 5S RNA has essentially the same structure among all prokaryotic species. The same is true for eukaryotic 5S RNAs. Prokaryotic and eukaryotic 5S RNAs are also quite similar to each other, except for a difference in a specific region. By comparing the nucleotide alignment from the juxtaposed 5S RNA secondary structures, a phylogenic tree of nineteen organisms was constructed. The time of divergence between prokaryotes and eukaryotes was estimated to be 2.5 X 10(9) years ago (minimum estimate: 2.1 X 10(9).
TL;DR: The incidence of salivary gland tumors among the exposed individuals was significantly higher, 2.6 times greater than that among the nonexposed individuals for all tumors, and 10 times greater for malignant tumors.
Abstract: An epidemiologic investigation was undertaken in Hiroshima to study the relationship of salivary gland tumors to exposure to ionizing radiation. Two hundred and eleven cases examined between 1953-1971 were confirmed by a review of histologic specimens. Of these, 66 cases occurred in residents of Hiroshima City who were born before the A-bomb: 30 among A-bomb-exposed, and 36 in non-exposed individuals. The incidence of salivary gland tumors among the exposed individuals was significantly higher, 2.6 times greater than that among the nonexposed individuals for all tumors, and 10 times greater for malignant tumors. The incidence increased with proximity to the hypocenter for the directly exposed. An increased incidence was also found among early entrants, particularly those entering the city within 3 days of the A-bomb.
TL;DR: The distribution in six Porella species of drimane-, aromadendrane-and pinguisane-type sesquiterpenes and norsesquiterbenes is described in this article.
TL;DR: The conventional Markov renewal process is based on the regeneration points at which the process enters each of the states as mentioned in this paper, but it is of great interest to discuss the non-regeneration points.
TL;DR: In this paper, an atomic-absorption spectrophotometric method for the rapid and sensitive determination of arsenic, antimony, and selenium with the hydride-argon/hydrogen flame system has been studied.
Abstract: An atomic-absorption spectrophotometric method for the rapid and sensitive determination of arsenic, antimony, and selenium with the hydride-argon/hydrogen flame system has been studied. The comparison of the zinc tablet combined with stannous chloride and potassium iodide, and the sodium borohydride tablet reduction systems are described. The sensitivities and precisions of both reduction systems are estimated to be nearly the same. From the results of the comprehensive study on interferences, the zinc system is concluded to be more selective than the sodium borohydride system, which is especially true for arsenic.