Showing papers by "Osaka University published in 1980"
TL;DR: In this article, a series of native and sonicated samples of schizophyllan and extracellular β-1,3-D-glucan were collected from sedimentation equilibrium, light scattering, and viscosity measurements on a set of native species.
Abstract: From sedimentation equilibrium, light scattering, and viscosity measurements on a series of native and sonicated samples of schizophyllan, and extracellular β-1,3-D-glucan, the following results were obtained: (i) weight-average and z-average molecular weights (Mw and Mz) in water are about three times as large as those in dimethylsulfoxide (DMSO); (ii) the exponent in the Houwink-Mark-Sakurada intrinsic viscosity relation in water is close to 1.7, whereas in DMSO it is 0.68; (iii) intrinsic viscosities of samples with Mw below 5 × 105 in water at 25°C can be fitted by Yamakawa's theory for along rigid rod if the pitch (1.836 nm) of the triple helix of Atkins et al. and the diameter (3 nm) estimated from the model triple helix are used; (iv) intrinsic viscosities in water-DMSO mixtures at 25°C undergo and almost discontinuous decrease when the weight fraction of DMSO in the mixture increases to about 87%. These results combined lead to the conclusion that schizophyllan dissolves in water as a triple helix similar to that proposed by Atkins et al. and that the triple helix in aqueous DMSO solution “melts” abruptly to single chains when the DMSO coposition reaches about 87 wt%. It was also found that the triple helix is not recoverable once it is broken in DMSO.
310 citations
TL;DR: The control mechanism of the coordinated finger tapping by both hands may be composed of a coupled system of two neural oscillators each of which controls the right and the left finger tapping respectively.
Abstract: Recently, it was found that rhythmic movements (e.g. locomotion, swimmeret beating) are controlled by mutually coupled endogeneous neural oscillators (Kennedy and Davis, 1977; Pearson and Iles, 1973; Stein, 1974; Shik and Orlovsky, 1976; Grillner and Zangger, 1979). Meanwhile, it has been found out that the phase resetting experiment is useful to investigate the interaction of neural oscillators (Perkel et al., 1963; Stein, 1974). In the preceding paper (Yamanishi et al., 1979), we studied the functional interaction between the neural oscillator which is assumed to control finger tapping and the neural networks which control some tasks. The tasks were imposed on the subject as the perturbation of the phase resetting experiment. In this paper, we investigate the control mechanism of the coordinated finger tapping by both hands. First, the subjects were instructed to coordinate the finger tapping by both hands so as to keep the phase difference between two hands constant. The performance was evaluated by a systematic error and a standard deviation of phase differences. Second, we propose two coupled neural oscillators as a model for the coordinated finger tapping. Dynamical behavior of the model system is analyzed by using phase transition curves which were measured on one hand finger tapping in the previous experiment (Yamanishi et al., 1979). Prediction by the model is in good agreement with the results of the experiments. Therefore, it is suggested that the neural mechanism which controls the coordinated finger tapping may be composed of a coupled system of two neural oscillators each of which controls the right and the left finger tapping respectively.
300 citations
TL;DR: The instrument has been useful in monitoring arterial oxygenation in patients with respiratory failure in the authors' intensive-care unit and the reproducibility was assessed in a healthy subject by measuring the oxygen saturation repeatedly 60 times.
Abstract: A noninvasive oximeter that analyses the oxygen saturation of arterial blood in the fingertip is described. The light, after attenuating the infrared portion to avoid thermal injury, is applied to the fingertip through an optical transmitter made of glass fibres. The transmitted light is transferred to an optical reception system where a spectrophotometric determination of oxygen saturation is performed. The determination is performed by considering only the change in the attenuation of light caused by the inflow of arterial blood into the fingertip. The correlation between the oxygen saturation measured with the present instrument (y) and that with the blood-gas method (x), was y=0·907x+8·592 with a standard deviation and a correlation coefficient of 0·135% and 0·983, respectively. The reproducibility was assessed in a healthy subject by measuring the oxygen saturation repeatedly 60 times. The mean saturation was 95·82±0·675% (mean±standard deviation). The instrument has been useful in monitoring arterial oxygenation in patients with respiratory failure in our intensive-care unit. One of the disadvantages of the instrument is that the measurement is interrupted when the fingertip changes its position against the light beam.
270 citations
TL;DR: ML-236B, a competitive inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase, was administered to 11 patients with primary hypercholesterolemia and saw a marked reduction in tuberous xanthomas, but here the drug was less effective in reducing the serum cholesterol level and a higher dose was required for treatment.
217 citations
TL;DR: In this article, a palladium-catalyzed reaction of vinyl bromide with dialkyl phosphite is described, which is stereoselectively prepared by palladium catalyzed reaction.
212 citations
TL;DR: It is proposed that the 216 cm−1 line of deoxy Hb is associated primarily with the FeNe(HisF8) stretching mode and accordingly that the Fe £1,000,000 bond is stretched in the T state due to a strain exerted by globin.
198 citations
194 citations
TL;DR: Results are interpreted with respect to the replicating fork of DNA, a structure postulated to be involved in the formation of spontaneous and UV-induced SCE, and a new model for SCE formation is proposed.
Abstract: Effects of inhibitors of DNA synthesis on spontaneous and ultraviolet light (UV)-induced sister-chromatid exchanges (SCE) were examined in a Chinese hamster cell line, V79 B-1. The inhibitors used were hydroxyurea (HU), 1-beta-D-arabinofuranosylcytosine (ara-C), aphidicolin (APC), 2',3'-dideoxythymidine triphosphate (ddTTP), neocarzinostatin (NCS), novobiocin (NB) and cycloheximide (CHX). HU, ara-C, and APC increased spontaneous SCE frequency, and had a synergistic effect on UV-induced SCE frequency. DdTTP, NCS and NB failed to show any statistically significant effect on either spontaneous or UV-induced SCE frequencies, though NCS and NB did slightly increase both spontaneous and UV-induced SCE frequencies. On the contrary, CHX decreased spontaneous SCE frequency, and more drastically, also UV-induced SCE frequency. These results are interpreted with respect to the replicating fork of DNA, a structure postulated to be involved in the formation of spontaneous and UV-induced SCE. A new model for SCE formation is proposed.
185 citations
TL;DR: In this article, the Schottky barrier formed at the interface between palladium film and n-type titanium oxide (TiO 2 ) single crystal is sensitive to hydrogen or other reducing gases in the ambient.
178 citations
TL;DR: It is pointed out that the consequence inferred by the methods suggested does not always fit intuitions and improved methods are suggested which fit the authors' intuitions under several criteria.
171 citations
TL;DR: The three-dimensional structure of a [2Fe-2S] ferredoxin of Spirulina platensis, a blue-green alga, determined by X-ray crystallography at 2.5 Å resolution is reported and the characteristic features of the molecule are discussed in relation to the molecular evolution of ferredoxins of this class.
Abstract: Ferredoxins are iron–sulphur proteins with either one or two [4Fe-4S] clusters or one [2Fe-2S] cluster and they function as electron carriers in diverse metabolic systems. Extensive comparative studies on the primary structures of ferredoxins with low oxidation–reduction potentials from a wide variety of organisms have provided information on the structure–function and evolutionary relationships of these proteins1,2. In addition, the three-dimensional structure of Peptococcus aerogenes 2[4Fe-4S] ferredoxin has been elucidated3. However, nothing is known about the three-dimensional structure of [2Fe-2S] ferredoxins such as those of chloroplasts. Here we report the three-dimensional structure of a [2Fe-2S] ferredoxin of Spirulina platensis, a blue-green alga, determined by X-ray crystallography at 2.5 A resolution, and discuss the characteristic features of the molecule in relation to the molecular evolution of ferredoxins of this class.
TL;DR: Results correspond well with the observed fact that stroke incidence or death rate in Japan is higher in populations with high prevalence of hypertension and low concentration of cholesterol, and also with the fact that death rate from hemorrhage declines with the increment of serum total cholesterol and the westernization of diet.
TL;DR: The central fiber connections of the gustatory system (VII, IX, and X nerves) in the crucian carp were examined by the Fink‐Heimer method and its modification.
Abstract: The central fiber connections of the gustatory system (VII, IX, and X nerves) in the crucian carp were examined by the Fink-Heimer method and its modification.
The sensory and recurrence roots of the VII enter the brainstem separately and terminate in the ipsilateral half of the facial lobe (L-VII). Afferent fibers of the IX terminate in the glossopharyngeal lobe (L-IX). Most afferent fibers of the X terminate in the sensory layer of the vagal lobe (L-X), in which degenerating terminals occur in some laminae. Some vagal afferents project bilaterally to the commissural nucleus of Cajal. The cutaneous component of the X projects to the nucleus of the spinal trigeminal tract (SpV) and the medial funicular nucleus (nFM).
Ascending secondary fibers from the L-VII project bilaterally to the secondary gustatory nucleus (nGS) in the isthmus region. Descending secondary fibers from the L-VII turn caudally in the SpV. These fibers terminate mostly in the nucleus of the SpV and sparsely in the nFM. The L-IX and L-X give rise to the long and short secondary paths. The long path projects as the ascending secondary tract to the ipsilateral nGS. The short path includes secondary fibers projecting to the motor layer of the L-X and the medullary reticular formation.
Tertiary gustatory fibers arising in the nGS project ipsilaterally to two diencephalic nuclei: the nucleus glomerulosus and the nucleus diffusus lobi inferioris.
TL;DR: In this paper, an equation of the residual excess pore pressure, represented as a function of both the maximum cyclic shear strain and the overconsolidation ratio, is deduced.
Abstract: Effects of some factors on the excess pore pressure are clarified, followed by an examination of the reliability of cyclic pore pressure measurement, the normalization of stresses, and the failure due to cyclic loading of clays. An equation of the residual excess pore pressure, represented as a function of both the maximum cyclic shear strain and the overconsolidation ratio, is deduced. An overconsolidated state due to the cyclic stress-strain history is similar in strength to one due to the ordinary overconsolidation history. In spite of the temporary loss in strength and deformation modulus immediately after cyclic loading, the dissipation of pore pressures leads to higher strength and deformation modulus than the initial ones before cyclic loading. It is implied that cyclic stress-strain history can be one of the factors causing natural ground to become lightly overconsolidated.
TL;DR: It is suggested that this side-chain locks helix A firmly to its neighbouring segments in the polypeptide chain, and by doing so, mimics the action of DPG in stabilizing the tertiary deoxy structure of the β subunits.
TL;DR: The present study further clarified the organization of the components of the MFB ascending from the lowerbrain stem, and provided some additional anatomical substrates for the physiology of the control of the forebrain by the lower brain stem neurons.
TL;DR: In this paper, an algorithm for the solution of optimal control problems with constraints on the control, but without constraints on trajectory or the terminal state, is presented, where reduction of a cost at each iteration is guaranteed.
Abstract: This paper presents an algorithm for the solution of optimal control problems with constraints on the control, but without constraints on the trajectory or the terminal state In this algorithm, reduction of a cost at each iteration is guaranteed Global convergence conditions for the algorithm are investigated and an example is worked out
TL;DR: The ultrastructure of the optic tectum in the squirrel fish, Holocentrus rufus, has been studied and the normal synaptic organization is described.
Abstract: The ultrastructure of the optic tectum in the squirrel fish, Holocentrus rufus, has been studied and the normal synaptic organization is described. Synaptic terminals were classified into eight types (S1-S6, F1, F2) by their morphology and synaptic relations. The distribution pattern for each type of terminal was determined by counting the relative number of terminals in each layer. Most S1 terminals are localized in Stratum marginale (SM), whereas S2 terminals are most common in Stratum fibrtosum et griseum superficiale (SFGS). S3, S4, S5, F1, and F2 terminals are limited mainly to SFGS and Stratum griseum centrale (SGC). S6 terminals are most frequently seen in SGC and Stratum griseum periventriculare (SPV). In order to determine the origins of the various types of synaptic terminals in the optic tectum, the telencephalon, eye, and optic tectum were removed unilaterally and areas of resultant degeneration examined. Electron microscopic observations show that nearly all S2 terminals in SFGS of the contralateral optic tectum degenerate after eye enucleation, whereas some S4 terminals in SFGS and SGC exhibit degenerative changes after removal of the ipsilateral telencephalon. Unilateral ablation of the optic tectum was associated with degenerative changes in occasional S5 terminals within SGC of contralateral optic tectum. All experiments resulted in some increased electron density of S3 and F terminals, some of which were identified as F2 terminals. The possible origins of S1 and S6 terminals, which were not altered in the present experiments, are discussed.
TL;DR: Specific radioimmunoassays were used to measure somatostatin and vasoactive intestinal peptide in portal and peripheral plasma from conscious dogs prepared with indwelling portal catheters, and in six animals with intact stomachs, a test meal induced a significant rise of portals and peripheral som atostatin.
TL;DR: In this paper, a new convenient route to silyl ethers and esters from alcohols and carboxylic acids using allylsilanes in the presence of an acid catalyst in acetonitrile was developed.
TL;DR: A unified treatment of a large class of multiterminal noiseless source coding problems including all previously studied situations is presented and a unified achievable rate region is established by a coding technique based on the typical sequence criterion.
Abstract: A unified treatment of a large class of multiterminal noiseless source coding problems including all previously studied situations is presented. A unified achievable rate region is established for this class by a coding technique based on the typical sequence criterion. This region is tight for all the previously studied situations.
TL;DR: In this article, the dynamics of the biped locomotion system with many degrees of freedom are analyzed from a control theoretic point of view, and a control system for dynamical bipeds locomotion is constructed based on this fact.
Abstract: The dynamics of the biped locomotion system with many degrees of freedom are analyzed from a control theoretic point of view. By the use of the singular perturbation technique, it is shown that biped locomotion can be divided into two modes with respective time scales, the fast mode and the slow mode. Based on this fact, a control system for dynamical biped locomotion is constructed. The effectiveness of the proposed control algorithm is verified using computer simulation.
TL;DR: In this paper, the slip geometry and the dislocation arrangements in the intermetallic compound FeAl with the CsCl structure have been studied at temperatures between 470 and 1000 K.
Abstract: Single crystals of the intermetallic compound FeAl with the CsCl structure have been deformed in compression at temperatures between 470 and 1000 K to study the slip geometry and the dislocation arrangements in this material at high temperatures. At temperatures below 0·44 of the melting temperature, T m, slip occurs on the {110}〈111〉 systems, while at 0·44T m, the transitions in the slip directions from 〈111〉 to 〈001〉 takes place for orientations in the right-hand side of the unit stereographic triangle, i.e. near the [011]-[111] boundary and, as the deformation temperature is increased, the region showing the 〈001〉-type slip becomes wider. The critical resolved shear stress for both types of slip exhibits a strong temperature dependence above 0·44T m. The dislocation arrangements in crystals deformed by the slip of 〈001〉 type is found to consist mostly of edge dislocations. The occurrence of the 〈001〉-type slip at such a high temperature is suggested to be associated with compositional deviatio...
TL;DR: The findings suggest that activation and destabilization have a common mechanism which involves a small molecular weight component(s) and that molybdate has a specific inhibitory effect on this mechanism.
Abstract: The effects of molybdate on activation and stability of glucocorticoid, androgen, and estrogen receptors were studied. The activation of steroid receptors by heating or dialysis was inhibited by molydate, but molybdate had no effect on the nuclear binding of previously activated steroid-receptor complexes. The inhibitory effect of molybdate on activation was concentration dependent and was reversed when molybdate was removed by dialysis or gel filtration on Sephadex G-25. The steroid-binding capacities of the unoccupied glucocorticoid and androgen receptors were markedly reduced by removal of a small molecular weight factor(s) from the cytosol by dialysis or gel filtration on Sephadex G-25, even at 0 C. Molybdate blocked both this loss of steroid-binding ability on dialysis and also the heat-induced destabilization of the receptors. The dialysate of rat liver cytosol and molybdate had synergistic effects in increasing the stability of the glucocorticoid receptor in the cytosol after gel filtration at 25 C. These findings suggest that activation and destabilization have a common mechanism which involves a small molecular weight component(s) and that molybdate has a specific inhibitory effect on this mechanism.
TL;DR: In this article, the surface structure of the CoO�MoO3Al2O3 catalysts was found to be highly sensitive to the preparation method, and Bilayer structures were proposed for the catalysts prepared by sequential impregnations.
TL;DR: A phenomenological two-oscillator model that shows simultaneous stability of the two alternative phase relationships and the hysteresis phenomena found in Tupaia is proposed.
TL;DR: Two new algorithms are proposed for enumerating all the cutsets or all the s-t cutsets separatmg two spectfied verttces s and t m an undirected graph and how good the performance of the old algorithm is, when a given graph is "dense."
Abstract: Thts paper deals wRh the problem of enumerating all the cutsets or all the s-t cutsets separatmg two spectfied verttces s and t m an undirected graph A vanety of approaches have been proposed for this problem, among which one based on the partmon e ra set of veruces rote two sets is the most effi¢ienL It is first shown that an algorithm of this type has time complexity O((n + m)(n log2#)#), and two new algorithms with ume complexity O((n + m)O + I)) are then proposed One of these new algorithms has space complexity O(nZ), and the other has space complexity O(n + m), where n and m are the numbers of veraces and edges, respectively, and ta ts the number ofs-t cutsets m a given graph The results of some computatmnal experiments are also described. An mvest~gaUon ~s made of the extent to whtch the new algorithms are better, and how good the performance of the old algorithm is, especmlly when a given graph is \"dense,\" t e , 2m/(n(n 1)) _> 0.4.
TL;DR: Results clearly show that not only the sequence encoding the CH4 domain but also the 5'-flanking (S mu) sequence is conserved between human and mouse mu genes, suggesting that the nucleotide sequence in the S mu region has an important biological function.
Abstract: We have cloned a 12 kb DNA segment containing human mu gene and its flanking sequence from human fetal liver DNA library using mouse mu gene as a probe. Partial nucleotide sequence determination shows that the cloned DNA contains the sequence encoding human mu chain. This is the first constant region gene of the human heavy chain that is cloned. We have compared human and mouse mu genes by heteroduplex analysis and Southern blot hybridization. The results clearly show that not only the sequence encoding the CH4 domain but also the 5'-flanking (S mu) sequence is conserved between human and mouse mu genes, suggesting that the nucleotide sequence in the S mu region has an important biological function, presumably a recognition signal for the class switch recombinant as proposed previously.
TL;DR: The activity of ornithine decarboxylase in rabbit costal chondrocytes in culture increased markedly after addition of parathyroid hormone (PTH), followed by increase in the intracellular concentrations of polyamines, especially putrescine, which increased in 6 hr to about 3-fold that of untreated cultures.
Abstract: The activity of ornithine decarboxylase (OD-Case:L-ornithine carboxy-lyase, EC 4.1.1.17) in rabbit costal chondrocytes in culture increased markedly after addition of parathyroid hormone (PTH), reaching a maximum 4 to 5 hr after PTH addition. The increase in ODCase activity was followed by increase in the intracellular concentrations of polyamines, especially putrescine, which increased in 6 hr to about 3-fold that of untreated cultures. The induction of ODCase by PTH was not observed in L, 3T3, HeLa, buffalo rat liver, or BHK cells. Retinyl acetate and retinoic acid both inhibited expression of the differentiated phenotype of chondrocytes by rabbit costal chondrocytes in culture within 3 days after their addition, as judged by morphological change and decrease in sulfate incorporation into glycosaminoglycans but did not inhibit cell proliferation. PTH could not induce an increase in ODCase in de-differentiated cells that had been pretreated with retinyl acetate or retinoic acid for 3 days. but 4 days after removal of the retinoids, these de-differentiated cells regained the ability to synthesize ODCase in response to PTH. These facts suggest that the induction of ODCase and the formation of putrescine by PTH are good markers of the differentiated phenotype of cultured chondrocytes.
TL;DR: A revised GMDH (Group Method of Data Handling) algorithm is developed in which heuristics are not required such as dividing the available date and checking data, pred determining the structure of the partial polynomials, or predetermining the number of intermediate variables.
Abstract: In this paper a revised GMDH (Group Method of Data Handling) algorithm is developed in which heuristicsare not required such as dividing the available date. into training data and checking data, predetermining the structure of the partial polynomials, or predetermining the number of intermediate variables. In this algorithm the prediction error criterion, such as PSS (Prediction Sum of Squares) or AIC (Akaike's Information Criterion) evaluated from all the available data, in used as a criterion for generating optimal partial polynomials, for selecting intermediate variables and for stopping the multilayered iterative computation. This heuristics freeGMDH algorithm is applied to non-linear modelling for short-term prediction of air pollution concentration. By using the time series data of SO2, concentration, the wind velocity and the wind direction in Tokushima; Japan, a suitable model for predicting SO2concentration at a few hours in advance is developed. The predicted results obtained by the rev...