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  • 1
    Electronic Resource
    Electronic Resource
    Thermal stability of the cellulose synthase complex of Acetobacter xylinum (1999)
    Springer
    Cellulose 6 (1999), S. 137-152 
    Details
    ISSN: 1572-882X
    Keywords: Acetobacter xylinum ; cellulose synthase ; thermostability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The thermal stability of the cellulose synthase complex of Acetobacter xylinum has been analyzed in terms of enzyme activity loss as well as detection of its two major components (83 kDa and 93 kDa polypeptides) in polyacrylamide gels under different electrophoretic sample treatment conditions. The cellulose synthase complex intrinsically is a thermally unstable enzyme and quickly loses its in vitro activity beyond 35° C. The 83 kDa polypeptide has been found to be more labile than the 93 kDa polypeptide. When boiled in lithium dodecyl sulfate (LDS) buffer, the 83 kDa polypeptide is destroyed through peptide hydrolysis while the 93 kDa polypeptide remains uncleaved. The 83 kDa polypeptide is destroyed in LDS buffer at elevated temperatures beyond 55° C. When boiled in the absence of LDS buffer, the 83 kDa polypeptide is completely aggregated, while the 93 kDa polypeptide is only partially aggregated. In the absence of LDS buffer, the complete thermal aggregation of the 83 kDa polypeptide occurs at elevated temperatures beyond 85° C. The aggregation process has been quantitatively analyzed by a newly‐introduced quantitative index, Td (the temperature at which half the quantity of 83 kDa polypeptide disappears due to aggregation). The Td determined for the 83 kDa polypeptide in the product‐entrapped fraction is 48° C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009208610922
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  • 2
    Electronic Resource
    Electronic Resource
    Faint field galaxies: an explanation of the faint blue excessusing number evolution models (2000)
    Springer
    Astrophysics and space science 274 (2000), S. 557-579 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Pure luminosity evolution models for galaxies provide an unacceptable fit to the redshifts and colors of faint galaxies. In this paper we demonstrate, using HST morphological number counts derived both from the I 814-band of WFPC2 in the Medium Deep Survey (MDS) and the Hubble Deep Field (HDF) and from the H 1.6-band of NICMOS, and ground-based spectroscopic data of the Hawaii Deep Field and the Canada-France Redshift Survey, that number evolution is necessary for galaxies, regardless of whether the cosmic geometry is flat, open, or Λ-dominated. Furthermore, we show that the number evolution is small at redshifts of z〈1, but large at z〉1, and that this conclusion is valid for all the three cosmological models under consideration. If the universe is open or Λ-dominated, the models, which are subject to the constraint of the conservation of the comoving mass density of galaxies, naturally predict a population of star-forming galaxies with the redshift distribution peaking at z=2∼ 3, which seems to be consistent with the recent findings from Lyman-break photometric selection techniques. If the cosmological model is flat, however, the conservation of the comoving mass density is invalid. Hence, in order to account for the steep slope of B-band number counts at faint magnitudes in the flat universe, such a star-forming galaxy population has to be introduced ad hoc into the modelling alongside the merger assumption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026535611877
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  • 3
    Electronic Resource
    Electronic Resource
    Immunochemical studies of the cellulose synthase complex inAcetobacter xylinum (1996)
    Springer
    Cellulose 3 (1996), S. 63-75 
    Details
    ISSN: 1572-882X
    Keywords: antibodies ; cellulose synthase ; Acetobacter xylinum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract An immunochemical method was used to analyse the 83 and 93 Kd polypeptides of cellulose synthase from Acetobacter xylinum.Polyclonal antibodies were raised against the LDS-PAGE-fractionated 83 and 93 Kd polypeptides isolated from A. xylinum.Using these antibodies, the 83 and 93 Kd polypeptides were localized in the different fractions during purification of cellulose synthase, and the ratio of these two polypeptides was determined to be 1∶1. A differential solubilization of the 83 and 93 Kd polypeptides from the cell strongly suggested that the mechanism by which these two polypeptides originate from a single acsAB gene product (Saxena et al.,1994) must be via a post-translational cleavage. The results of trypsin treatment of the membrane fraction used in the purification of cellulose synthase were analysed to determine the fate of these two polypeptides and their relationship to the enzyme activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02228791
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  • 4
    Electronic Resource
    Electronic Resource
    Low temperature co-fired AlN multilayer substrates (1997)
    Springer
    Journal of materials science 8 (1997), S. 233-238 
    Details
    ISSN: 1573-482X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A process for low temperature co-fired AlN multilayer substrates is introduced. Some key factors about this technology are delineated and discussed. A two-step burnout process may solve the contradiction between tungsten oxidation and carbon removal. Sintering with additives appears to improve densification at low temperature. DyN was found as a second phase in AlN ceramics, which suggests that Dy2O3 efficiently removes oxygen from the AlN lattice. The microstructure of AlN ceramics is ideal for achieving high thermal conductivity. Analysis of the AlN-W interface showed there were no second phases, but there was probably an intricate interlocking structure between the grains of tungsten and AlN. Co-firing at 1650°C for 4 h produced an AlN multilayer substrate with a thermal conductivity of up to 130 W m−1 K−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018514717837
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  • 5
    Electronic Resource
    Electronic Resource
    Heat transfer from a rarefied plasma flow to a metallic or nonmetallic particle (1986)
    Springer
    Plasma chemistry and plasma processing 6 (1986), S. 313-333 
    Details
    ISSN: 1572-8986
    Keywords: Heat transfer to metallic and nonmetallic particles ; free-molecule flow regime ; two-temperature plasma ; reduced pressure ; analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Heat transfer from a plasma flow to a metallic or nonmetallic spherical particle is studied in this paper for the extreme case of free-molecule flow regime. Analytical expressions are derived for the heat flux due to, respectively, atoms, ions, and electrons and for the floating potential on the sphere exposed to a two-temperature plasma flow. It has been shown that the local or average heat flux density over the whole sphere is independent of the sphere radius and approximately in direct proportion to the gas pressure. The presence of a macroscopic relative velocity between the plasma and the sphere causes substantially nonuniform distributions of the local heat flux and enhances the total heat flux to the sphere. The heat flux is also enhanced by the gas ionization. Appreciable difference between metallic and nonmetallic spheres is found in the distributions along the oncoming flow direction of the floating potential and of the local heat flux densities due to ions and electrons. The total heat flux to the whole sphere is, however, almost the same for these different spheres. For a fixed value of the electron temperature, the heat flux decreases with increasing temperature ratio Te/Th.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00565548
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of platelet-activating factor (PAF) on sodium calcium exchange in cardiac sarcolemmal vesicles (1990)
    Springer
    Molecular and cellular biochemistry 92 (1990), S. 45-51 
    Details
    ISSN: 1573-4919
    Keywords: heart ; sarcolemma ; platelet-activating factor ; sodium-calcium exchange ; calcium binding ; calcium efflux
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The effects of platelet-activating factor (PAF) on Na+-dependent calcium uptake in myocardial sarcolemmal vesicles were examined in order to clarify its mechanism of inotropic action on the heart. PAF (40 and 20 µM) significantly inhibited Na+-Ca2+ exchange by 61% and 37%, respectively. Both initial rate of exchange and maximal exchange were inhibited. The Km for the reaction was not altered but Vmax was lowered 55% by PAF. Lyso-PAF inhibited Na+-Ca2+ exchange to a similar degree as PAF. CV-3988, a specific PAF receptor antagonist, failed to diminish the inhibitory effect of PAF on Na+-Ca2+ exchange, suggesting that the effect of PAF on Na+-Ca 2+ exchange is not via a receptor mechanism. The passive permeability of sarcolemmal vesicles to Ca2+ was markedly elevated after PAF treatment. However, this effect could not account for the decrease in Na+-Ca2+ exchange. Interestingly, passive Ca2+ binding to cardiac sarcolemma was increased by 40 µM PAF. This study indicates that a depression of Na+-Ca2+ exchange probably does not play a role in the negative inotropic effect of PAF on the myocardium under physiological conditions. Its mechanism of action on Na+-Ca2+ exchange is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220718
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  • 7
    Electronic Resource
    Electronic Resource
    Comparative mapping of QTLs for agronomic traits of rice across environments by using a doubled-haploid population (1997)
    Springer
    Theoretical and applied genetics 94 (1997), S. 145-150 
    Details
    ISSN: 1432-2242
    Keywords: Key wordsDoubled-haploid population  ; Quantitative trait loci (QTLs)  ;  Molecular map  ; Rice  ;  G×E interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report here the RFLP mapping of quantitative trait loci (QTLs) which affect some important agronomic traits in cultivated rice. An anther culture-derived doubled-haploid (DH) population was established from a cross between indica and japonica rice varieties. A molecular linkage map comprising 137 markers was constructed based on this population which covered the rice genome at intervals of 14.8 cM on average. The linkage map was used to locate QTLs for such important agronomic traits as heading date, plant height, number of spikelets per panicle, number of grains per panicle, 1 000-grain weight and the percentage of seed set, by interval mapping. Evidence of genotype-by-environment interaction was found by comparing QTL maps of the same population grown in three diverse environments. A total of 22 QTLs for six agronomic traits was detected which were significant in at least one environment, but only seven were significant in all three environments; seven were significant in two environments and eight could only be detected in a single environment. However, QTLs-by-environment interaction was trait dependent. QTLs for spikelets and grains per panicle were common across environments while traits like heading date and plant height were more sensitive to environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050393
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  • 8
    Electronic Resource
    Electronic Resource
    Morphologies and growth mechanisms of aluminium nitride whiskers (1997)
    Springer
    Journal of materials science 32 (1997), S. 1969-1975 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Morphologies of AlN whiskers grown by the vapour–liquid–solid mechanism (VLS) were investigated. Several types of whisker structures, such as growth hill, wavy, crossed and stack structures, were found due to the variation of growth conditions. Growth mechanisms and orientations of AlN whiskers were also studied. Besides preferential crystallographic planes, several other planes were found to be growth layers due to the perturbation of the AlN lattice change caused by dissolution of oxygen. A screw dislocation growth mechanism was clearly confirmed. An oblique growth mechanism was found in this work, which may be the result of two processes: the vapour–liquid–solid process and dissolution of oxygen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018589831042
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  • 9
    Electronic Resource
    Electronic Resource
    Structure characteristics of AlN whiskers fabricated by the carbo-thermal reduction method (1998)
    Springer
    Journal of materials science 33 (1998), S. 4249-4253 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract With Al2O3 and graphite as raw materials, CaF2 and B2O3 as additives, AlN whiskers were fabricated by a carbo-thermal reduction method. The fabrication mechanism and growth characteristics of AlN whiskers were investigated. At the beginning of the high-temperature fabrication, AlN whiskers grew by the vapour/liquid/solid (VLS) mechanism, and defects existed on the surfaces of the whiskers. In later stages, the VLS mechanism possibly changed to a vapour/solid (VS) mechanism, and the defects disappeared. The orientation of most AlN whiskers was normal to $$\{ 10\bar 1n\} $$ (n=0, 1, 2, 3), and normal to $$\{ \bar 12\bar 1n\} $$ (n=0, 1, 2). The growth processes of both two-dimensional nucleation and screw dislocations existed at the same time. © 1998 Kluwer Academic Publishers
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004438210417
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  • 10
    Electronic Resource
    Electronic Resource
    Fractal geometry derived from geometric inversion (1990)
    Springer
    Applied mathematics and mechanics 11 (1990), S. 1075-1079 
    Details
    ISSN: 1573-2754
    Keywords: geometric inversion ; self-inverse fractal ; fractal osculation ; fractal envelope
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Mathematics , Physics
    Notes: Abstract In this paper, the conception of fractal geometry derived from geometric inversion is introduced. A ramified self-inverse fractal with symmetry and a self-inverse fractal dust set are constructed. The authors extend the conception of the fractal osculation and propose a new notion—fractal envelope. Finally, two examples of self-inverse fractal (soap and egg) are given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02015691
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