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  • Author or Editor: S. Kobayashi x
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Abstract  

In this study, we aimed to recognize the body abnormalities through determining the metallic balance of hair. We determinated multiple elements of patients hair with acute chromium poisoning by burn from the worst clinical condition to complete recovery. Elements determined were Al, Au, Br, Ca, Cl, Co, Cr, Cu, Fe, Hg, I, K, Mg, Mn, Na, S, Se, V and Zn by mondestractive neutron activation analysis. Comparing the clinical findings of a patient with acute chromium poisoning and metallic balance of his hair, we demonstrated that the metallic balance returned to the normal range with recovery from sickness, which suggested a promising possiblity to utilize this as one parameter indicative of clinical state.

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We examined GABAergic modulation on “slow” oscillation (<1.0 Hz) of the procerebrum in the terrestrial mollusk, Limax valentianus. Short application of GABA-receptor agonists slightly increased the frequency of a periodic oscillation in the procerebrum, whereas persistent application decreased it. GABA-receptor antagonists decreased the oscillatory frequency. The GABA-like immunoreactivities were found in the neuropil and the cell body layers of the procerebrum. Because GABAergic inhibition is known to be essential for the generation of “fast” synchronous neuronal oscillation in the CNSs in othre many animals, our present findings are first evidence suggesting that GABA modulates ‘slow’ oscillation in the CNS.

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Abstract  

Mössbauer spectroscopy was applied to an investigation of ancient iron slags, excavated at the ancient ruins for iron manufacturing in order to deduce the raw materials and operative conditions of the furnace. From the Mössbauer spectra, it was found that the slags consisted of fayalite, wüstite, ulvöspinel and magnetite.

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Gamma-aminobutyric acid (GABA)-containing neurons are capable of controlling network oscillations and their patterns in the widely divergent species. In the terrestrial slug, Limax valentianus , oscillatory activity of the procerebrum neurons is considered to encode the odor information. Previous studies showed that GABA is present in the central nervous system and may be involved in the control of neuronal activity of Limax . In the present study, we examined the effects of GABA on the generation of oscillatory activity in the procerebrum. The results suggest that the GABAergic synaptic transmission may be involved in the oscillatory neural network of the procerebrum.

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Abstract  

It was found that not only111mCd but also105Ag and106mAg sublimate at 1050 °C under a reduced pressure from Pd foils irradiated with -particles. The sublimation method has enabled rapid separation of the isotopes and repeated use of valuable Pd foils. Adsorption onte -Fe2O3 and coprecipitation with ferric hydroxide were studied by using radioactive tracers.

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The postnatal development of the corticothalamic projection from the lateral suprasylvian cortex (LS) to the lateral medialis-suprageniculate nucleus (LM-Sg) of the cat thalamus was assessed by means of the anterograde tracer biocytin. In the adult, two types of corticothalamic fibers were found: type I established a network of fine fibers present throughout the LM-Sg, it was characterized by a linear sequence of small (less than 0.5 m in diameter), single terminal boutons making contact mainly with thin dendrites and/or dendritic spines. Type II, found less frequently, gave off short, side branches near axon terminals and formed clusters of 5-10 large terminal boutons (0.5-1.5 m in diameter), making contact predominately with medium-sized dendrites and/or vesicle-containing profiles, forming a synaptic glomerulus. At birth (P0), anterogradely-labeled fibers were found in the LM-Sg as in adults. In the early postnatal period (until P6) as well as around the time of eye-opening (P7-P10) to P21, neonatal fibers were largely unbranched many of them having axons tipped with growth cones. Axon terminals containing synaptic vesicles were rarely observed but when present these exhibited considerable variation in their morphological appearance of synapses. Thus, it was not possible to categorize them into the two types of axons which characterize the adult. After P25, terminal swellings bearing a close resemblance to those of type II fibers begin to appear. In this way, the main two corticothalamic fiber types could be identified. These findings demonstrate that significant postnatal changes occur in the synaptology of corticothalamic fibers in the LM-Sg, particularly with the maturation of type II fibers.

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Abstract  

Chemical compositions of spherules separated from deep sea sediment dredged off Hawaiian islands and from Antarctic ice were measured by instrumental neutron activation analysis (INAA) using Kyoto University Reactor (KUR). Iron, cobalt, nickel, iridium, scandium and manganese contents in those spherules were determined to be 19.3–97.7%, 23–4370 mg·kg−1, 0.08–7.04%, 0.84–35.4 mg·kg−1, 1.4–44.3 mg·kg−1 and 93.4 mg·kg−1–7.2 %, respectively, and compared with each other. Particularly, iridium was detected in seven spherules among fourteen from Hawaii, but only one spherule among twenty-two from Antarctic, and those spherules turned out to be extraterrestrial in origin. However, it was shown that there was little difference in characteristics of elemental contents between both kinds of spherules, except for Ir-detected spherules.

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Abstract  

Chemical composition of 15 magnetic spherules collected from deep sea sediment was determined by instrumental neutron activation analysis (INAA) under two different irradiation conditions using the Kyoto University Reactor (KUR). Based on their chemical composition, nine spherules were judged to be of extraterrestrial origin. The differences in the chemical composition of the nine spherules are discussed in terms of condensation temperatures for the elements. Comparing the detection limits derived from INAA under two different irradiation conditions, the sensitivity for INAA using KUR is discussed.

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Abstract  

Airborne particulate matter was collected at the intersection of Industrial Road in Kawasaki-city, Kanagawa, Japan using a 12-stage low-pressure impactor. High concentrations of airborne particulate matter have been observed in this area. The collected samples were analyzed for 34 elements by instrumental neutron activation analysis (INAA), and data on the elemental concentrations were obtained. High concentrations of fine particles of As, Br, Sb, V, and Zn were observed. It was further observed that these fine particles were originated predominantly from the wear of tires and brakes, and not from automobile exhaust emissions.

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Summary  

A simple and reliable sampling system for 3H and 14C in airborne release from nuclear facilities was designed. The sampling system can collect 3H and 14C simultaneously with a condensation technique using a commercially available cold trap equipment and a CO2 absorption technique using an organic alkali monoethanolamine solution, respectively. In situ performance tests for the effluent from a reprocessing plant showed that the system has high and stable efficiencies for collecting 3H and 14C for a one-week batch sampling at a sampling flow rate of 0.4 l . min-1. These collection techniques also provided a simple procedure of following sample preparation for activity measurements by liquid scintillation counting. The detectable concentrations of the proposed monitoring method were 3.0 Bq . m-3 for 3H and 1.6 Bq . m-3 for 14C, respectively. The sensitivity would be on an acceptable level for routine monitoring of airborne release at nuclear facilities.

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