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  • 1
    Electronic Resource
    Electronic Resource
    Calcium regulating activity of 26,27-dimethyl analog of 24R,25-dihydroxyvitamin D3 (1994)
    Springer
    Calcified tissue international 55 (1994), S. 190-197 
    Details
    ISSN: 1432-0827
    Keywords: Bone resorption ; Osteoclast-like cell formation ; Bone Ca mobilization ; Intestinal Ca transport ; 24R,25-dihydroxy-26,27-dimethylvitamin D3
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract To determine the possibility that methyl substitution in 26- and 27-positions of 24R,25-dihydroxyvitamin D3 [24,25(OH)2D3] alters activities of the original compound, the effects of 24,25(OH)2D3 on calcium (Ca) regulating activity were compared with those of its methyl analog [24,25(OH)2(CH3)2D3] in addition to 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3]. 24,25(OH)2D3 at 10-6 M and 24,25(OH)2(CH3)2D3 at 10-7 M and above significantly stimulated both bone resorption in neonatal mouse calvaria cultures and formation of osteoclast-like multinucleated cells (MNC) in mouse bone marrow cultures. A stimulative effect of 1,25(OH)2D3 on bone resorption and MNC formation was recognized in very low concentrations (10-11 M and above). Although a potency of 24,25(OH)2(CH3)2D3 in stimulating bone calcium (Ca) mobilization and intestinal Ca transport was higher than that of 24,25(OH)2D3, the potencies of both compounds were similar to that of 1,25(OH)2D3 unlike in vitro experiments. As 1,24R,25-trihydroxy-26,27-dimethylvitamin D3 showed almost the same effect as 24,25(OH)2(CH3)2D3, the dihydroxy form is suggested to be hydroxylated at 1α position and converted to trihydroxy form in vitamin D-deficient rats. From these results, methyl substitution in 26- and 27-position of 24,25(OH)2D3 was found to elevate Ca regulating activity of the original compound. In addition, it is suggested that the basis for a similarity in potency between 1,25(OH)2D3 and 24,25(OH)2D3 or its dimethyl analog in vitamin D-deficient rats is likely the result of 1 α-hydroxylation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425874
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  • 2
    Electronic Resource
    Electronic Resource
    A new approach for n-beam dynamical calculations (1990)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 46 (1990), S. 94-98 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: With the use of modulated plane waves, a new method for n-beam dynamical calculations has been established on the basis of a paper by Watanabe, Kikuchi, Hiratsuka & Yamaguchi [Phys. Status Solidi A (1988), 109, 119-126]. The computing time is reduced to about one-sixth of what it originally was and a large reduction of memory is achieved, n-beam dynamical calculations of aluminium, copper and gold at several accelerating voltages and orientations were carried out in a completely parallel manner by the present method, the multi-slice method and Bethe's eigen-value method [Fujiwara (1959). J. Phys. Soc. Jpn 14, 1513-1524]. The present method turned out to be competitive with respect to accuracy and speed in comparison with the latter two methods. The new method makes n-beam dynamical calculations of complex systems and defects possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108767389010135
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  • 3
    Electronic Resource
    Electronic Resource
    Enhancement of protein secretion by optimizing protein synthesis: isolation and characterization of Escherichia coli mutants with increased secretion ability of alkaline phosphatase (1994)
    Springer
    Applied microbiology and biotechnology 41 (1994), S. 163-169 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Overexpression of the Escherichia coli phoA gene, coding for alkaline phosphatase, on multicopy plasmids caused the accumulation of the precursor form of alkaline phosphatase. The cells lost their viability by a half-life of 60 min and exhibited high sensitivity to 1% sodium dodecyl sulfate (SDS), suggesting that the assembly of the surface proteins were affected by overexpression of the phoA gene. From the cells exhibiting resistance to 1% SDS, we obtained 20 mutants that secrete more alkaline phosphatase into the periplasmic space. Three representatives of the mutants accumulated no precursor molecules and secreted alkaline phosphatase by five- to six-fold that of the wild-type cells carrying multicopy phoA. In all of the three mutants, the amount of phoA transcripts were two to four times less than those in the wild-type cells, indicating that the ability to secrete a large amount of alkaline phosphatase was conferred by decreasing the synthetic rates of the phoA gene product. When the promoter of phoA was replaced with the tacI promoter and the expression level of the phoA gene was regulated with isopropyl-1-thio-β-d-galactoside, the secretion of alkaline phosphatase into the periplasm decreased as the synthetic rate of the phoA gene product increased over a threshold. All these results indicate that overproduction of the phoA gene product causes defects in the secretion of alkaline phosphatase and that the regulation of the expression level is essential for efficient translocation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186954
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  • 4
    Electronic Resource
    Electronic Resource
    Enhancement of protein secretion by optimizing protein synthesis: isolation and characterization of Escherichia coli mutants with increased secretion ability of alkaline phosphatase (1994)
    Springer
    Applied microbiology and biotechnology 41 (1994), S. 163-169 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Overexpression of the Escherichia coli phoA gene, coding for alkaline phosphatase, on multicopy plasmids caused the accumulation of the precursor form of alkaline phosphatase. The cells lost their viability by a half-life of 60 min and exhibited high sensitivity to 1% sodium dodecyl sulfate (SDS), suggesting that the assembly of the surface proteins were affected by overexpression of the phoA gene. From the cells exhibiting resistance to 1% SDS, we obtained 20 mutants that secrete more alkaline phosphatase into the periplasmic space. Three representatives of the mutants accumulated no precursor molecules and secreted alkaline phosphatase by five- to six-fold that of the wild-type cells carrying multicopy phoA. In all of the three mutants, the amount of phoA transcripts were two to four times less than those in the wild-type cells, indicating that the ability to secrete a large amount of alkaline phosphatase was conferred by decreasing the synthetic rates of the phoA gene product. When the promoter of phoA was replaced with the tacI promoter and the expression level of the phoA gene was regulated with isopropyl-1-thio-β-D-galactoside, the secretion of alkaline phosphatase into the periplasm decreased as the synthetic rate of the phoA gene product increased over a threshold. All these results indicate that overproduction of the phoA gene product causes defects in the secretion of alkaline phosphatase and that the regulation of the expression level is essential for efficient translocation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050125
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  • 5
    Electronic Resource
    Electronic Resource
    Immunocytochemical survey of the neuropeithelial endocrine system in the respiratory tract of the Tokyo salamander, Hynobius neubulosus tokyoensis Tago (1994)
    Springer
    Histochemistry and cell biology 102 (1994), S. 425-431 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The epithelial lining of the respiratory tract of urodeles has been shown to harbor an innervated system of neuroepithelial endocrine (NEE) cells. Even between phylogenetically closely related species, large differences have been reported in the appearance and chemical coding of the NEE system. Although urodeles are well suited for the purpose, none of the prior studies have provided an immunocytochemical survey of the NEE system in all parts of the respiratory tract. In the present study, many bioactive substances and a general marker were immunocytochemically demonstrated in serial sections of the entire respiratory tract of the Tokyo salamander, Hynobius nebulosus tokyoensis, a species in which neuroepithelial bodies (NEBs) were previously characterized at the electron microscopic level. In the current study, serotonin-immunoreactive solitary NEE cells were observed in variable numbers in the larynx, in all parts of the trachea, and in areas of the lungs covered with ciliomucous epithelium. Serotonin-containing NEBs, however, were detected in small cranial areas of the lung only. Solitary NEE cells were seen in the trachea and lungs of H. nebulosus tokyoensis by immunocytochemical staining for somatostatin, calcitonin, calcitonin gene-related peptide, and bombesin, but the number, localization, and appearance of the labeled NEE cells differed considerably. Only calcitonin-like immunoreactivity was also noted in some NEB-like cell clusters in the cranial parts of the lungs. Unlike many other vertebrates, neuron specific enolase was found to be a poor marker for the NEE system in the salamander species used in this investigation. It may be concluded that the NEE system of H. nebulosus tokyoensis contains at least five different bioactive substances. The different markers, however, demonstrate the presence of NEE cells with obvious differences in respect to appearance and topographical distribution. The necessity is emphasized of reliable methods for adequate sampling of all regions of the respiratory tract in comparative histological studies of the NEE system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00269573
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  • 6
    Electronic Resource
    Electronic Resource
    Cycling behaviour of lithium-aluminium alloys formed on various aluminium substrates as negative electrodes in secondary lithium cells (1992)
    Springer
    Journal of applied electrochemistry 22 (1992), S. 620-627 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The cycling efficiencies of lithium were examined on various metal substrates using different methods. The efficiency was found to be strongly dependent on the evaluating method and on the alloying process of lithium with the metal substrates. The electrochemical behaviour of the Li−Al alloys formed on several kinds of thin Al substrates were investigated in 1m propylene carbonate solution of LiClO4 at room temperature. It was found that the cycling behaviour was dependent on the alloying rate of lithium with the Al substrate, and the electrochemically etched Al substrate, having a microstructure of a considerably preferred (100) orientation and a larger effective surface area, gave excellent cycling behaviour, showing a high cycling efficiency of 90∼85% at a high current density of ∼7 mA cm−2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01092610
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  • 7
    Electronic Resource
    Electronic Resource
    Electrochemical investigation of the diffusion of lithium in β-LiAl alloy at room temperature (1992)
    Springer
    Journal of applied electrochemistry 22 (1992), S. 728-732 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The chemical diffusion coefficients of lithium in β-LiAl alloy were measured by the use of transient techniques such as chronopotentiometry, chronoamperometry and a.c. impedance spectroscopy in 1 M LiClO4-propylene carbonate at 25° C. A β-LiAl layer, formed by electrodepositing lithium on a thin aluminium substrate having a microstructure of preferred (100) orientation, was mainly used. The values of the diffusion coefficients were found to be of the order of 10−10 cm2s−1, which are close to those reported in the literature. A scatter in the coefficient was discussed in terms of the formation and disruption of the passivating layer on the alloy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01027501
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  • 8
    Electronic Resource
    Electronic Resource
    Residual stress analysis of joints of ceramics and metals (1994)
    Springer
    Experimental mechanics 34 (1994), S. 116-124 
    Details
    ISSN: 1741-2765
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Development of reliable bonding techniques for ceramics and metals is considered to be very important for more useful applications of ceramics to machinery parts. However, a high thermal stress concentration occurs at the corner of bonded interface in ceramics during the bonding process. This occurs because of the difference in thermal properties of the bond materials and reduces the strength of the bonded joint considerably. The authors have been investigating various methods for effectively decreasing this stress concentration. In this paper, they present theoretical and experimental evidence that the stress concentration can be successfully diminished by varying the apex angle of joints. It is found that the tensile strength of joints increases as the apex angle of metals decreases from 90 deg to 45 deg. It also increases with increasing the apex angle of metals. Numerical calculations confirm these experimental results and the proposed procedure may be useful in the design and manufacture dissimilar joints.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02325708
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  • 9
    facet.materialart.
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    Cleavage of tRNA within the mature tRNA sequence by the catalytic RNA of RNase P: implication for the formation of the primer tRNA fragment for reverse transcription in copia retrovirus-like particles. (1990)
    National Academy of Sciences
    Details
    Publication Date: 1990-10-01
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
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  • 10
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    Enhancement of protein secretion by optimizing protein synthesis: isolation and characterization of Escherichia coli mutants with increased secretion ability of alkaline phosphatase (1994)
    Springer
    Details
    Publication Date: 1994-04-01
    Print ISSN: 0175-7598
    Electronic ISSN: 1432-0614
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Published by Springer
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