ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • kinetics
  • Springer  (29)
  • American Meteorological Society
  • 1995-1999
  • 1985-1989  (29)
  • 1965-1969
  • 1955-1959
  • 1950-1954
  • 1987  (14)
  • 1986  (15)
Collection
Keywords
Publisher
Years
  • 1995-1999
  • 1985-1989  (29)
  • 1965-1969
  • 1955-1959
  • 1950-1954
Year
  • 1
    Electronic Resource
    Electronic Resource
    Human vitamin C requirements (1987)
    Springer
    European journal of nutrition 26 (1987), S. 125-137 
    Details
    ISSN: 1436-6215
    Keywords: vitamin C ; functions ; kinetics ; pool ; saturation ; requirements ; RDA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Bedeutung von Vitamin C für den menschlichen Organismus wird aus den wichtigen Funktionen ersichtlich, an denen das Vitamin beteiligt ist, wie zum Beispiel Kollagen- und Karnitinsynthesen. In neuerer Zeit entdeckt wurde seine Rolle bei der Noradrenalinsynthese, der Inaktivierung von freien Radikalen sowie der Verhinderung der Nitrosaminbildung. Die Vielfalt dieser Vitamin-C-abhängigen Funktionen läßt erkennen, daß die Bedarfsfestsetzung für Vitamin C nicht nur die Verhütung der Mangelkrankheit Skorbut anvisieren, sondern auch berücksichtigen sollte, daß alle diese Funktionen jederzeit genügend Vitamin C zur Verfügung haben müßten, um optimal reagieren zu können. Das Konzept der Gewebesättigung kommt diesem Ziel am nächsten. Studien mit einem kinetischen Modell haben ergeben, daß eine Sättigung mit täglicher Einnahme von 100 mg Vitamin C bei Nichtrauchern und von 140 mg bei Rauchern eintritt, Mengen, die als optimale Werte gelten können. Bei verschiedenen Krankheiten dürfte der Bedarf höher sein; die genauen Mengen müssen jedoch erst noch ermittelt werden.
    Notes: Summary The importance of vitamin C is reflected in its multifunctional roles which include participation in collagen and carnitine syntheses, promotion of iron absorption and the more recently discovered participation in noradrenaline synthesis, inactivation of free radical chain reactions, prevention of N-nitroso compound formation and more. Given the many extra-antiscorbutic functions of the vitamin, the Recommended Dietary Allowances (RDA) should not just prevent deficiency disease but should aim at providing sufficient amounts for all vitamin C-dependent functions to operate at full capacity. The concept of vitamin C tissue saturation is best able to meet this demand. The use of kinetic models has shown that the body pool is saturated with a daily intake of 100 mg vitamin C in non-smokers and 140 mg in smokers, amounts that may be regarded as optimal RDA values. Certain disease states may be accompanied by still higher vitamin C requirements but the exact amounts are not yet known.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02019608
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Radical desorption in the emulsion polymerisation of vinyl monomers (1987)
    Springer
    Colloid & polymer science 265 (1987), S. 58-64 
    Details
    ISSN: 1435-1536
    Keywords: Polymerisation ; emulsion ; styrene ; methylmethacrylate ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The dependence of emulsion polymerisation rates on a number of important parameters is considered. Attention is paid to the use of seeded emulsion systems for the evaluation of radical desorption coefficients (k o). Experimental conditions are shown to be important. When the average number of radicals per particle is low, large changes in the rate coefficient for chain termination do not have a large effect on the kinetics. With styrene and methylmethacrylate, radical re-absorption by the polymer particles is shown to be important and radical capture efficiences can be high. Consistency is established between the results of a number of workers and values fork o are shown to be lower than those calculated from chain transfer rates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01422665
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ultrasonic absorption of the oxyethylene group in aqueous nonelectrolyte solutions (1986)
    Springer
    Journal of solution chemistry 15 (1986), S. 221-229 
    Details
    ISSN: 1572-8927
    Keywords: Ultrasonics ; kinetics ; aqueous solution ; triethylene glycol monobutyl ether
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The ultrasonic absorption from 6.5 to 220 MHz and velocities at 2.5 MHz have been measured in aqueous solution of triethylene glycol monobutyl ether as a function of concentration at 25°C. A single relaxational excess absorption, observed from 0.60 to 2.5 mol-dm−3, is attributed to a perturbation of an equilibrium associated with solute-solvent interaction. Rate constants for the forward and reverse processes have been determined from the concentration dependence of the relaxation frequency, and the influence on the water structure by an addition of the solute has been considered. Solution densities were also measured in order to obtain the expansivity of the solution. The standard volume and enthalpy changes of the reaction have been estimated from the concentration dependence of the maximum excess absorption per wave length. A linear relationship between the number of oxyethylene groups and the free energy change between bonded water and nonbonded water is established.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00646689
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Extradural and parenteral pethidine as analgesia after total hip replacement: Effects and kinetics. A controlled clinical study (1986)
    Springer
    European journal of clinical pharmacology 29 (1986), S. 529-534 
    Details
    ISSN: 1432-1041
    Keywords: pethidine ; epidural injections ; pain scores ; kinetics ; spinal cord
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Twenty-one patients who had undergone total hip replacement were randomly assigned to one of three groups in order to compare a single dose of 1 mg/kg of pethidine im (I) and 20 mg (II) or 60 mg of extradural pethidine (III) in a double-blind design. The degree of analgesia, the adverse effects, and the kinetics were studied for 18 h. Pain was monitored using a visual analogue scale (VAS). Supplementary doses of oxycodone if required were given no earlier than 0.75 h after pethidine. Plasma concentrations of pethidine were measured with gas chromatography mass spectrometry (GCMS). Hypoalgesia to pin prick test was evaluated. Low pain scores were observed in the extradural groups between 0.25 and 1.5 h after the dose. A significant difference in pain score compared with the im group was found after the higher extradural dose only between 0.5 and 1 h (p〈0.05). The area under the curve (AUC) of pain score versus time (0–18 h) was not significantly different between groups. The recorded adverse effects were minor in all three groups. The terminal half-lives and plasma clearances of pethidine, and the time to peak concentration were not different between the groups. Single patients in the extradural groups showed hypoalgesia to pin prick in parallel to the effect. The present study shows that extradural pethidine produces shortlived analgesia, in contrast to the long-lasting effect of morphine found in other studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00635888
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Dimyristoylphosphatidic acid/cholesterol bilayers (1986)
    Springer
    European biophysics journal 13 (1986), S. 343-353 
    Details
    ISSN: 1432-1017
    Keywords: Lipid/cholesterol ; phase transition ; kinetics ; second order transition ; pressure jump relaxation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Lipid bilayers and monolayers composed of dimyristoylphosphatidic acid (DMPA) and cholesterol were characterized by differential scanning calorimetry and film balance measurements. Increasing cholesterol content decreases the bilayer phase transition temperature and enthalpy in a manner similar to that observed before for other lipid/cholesterol systems. In monomolecular films at the air-water interface cholesterol exhibits the well known condensing effect in the liquid-expanded phase, while the liquid-condensed phase is less affected. As with the bilayer phase transition, the transition temperature and change in area at the liquid-condensed to liquid-expanded phase transition, as measured from isobars at 25 dynes/cm, decreases with increasing cholesterol content. The kinetics of the phase transition of DMPA/cholesterol bilayers were measured using the pressure jump relaxation technique with optical detection. Three relaxation times were observed. The relaxation times and amplitudes pass through maximum values at the transition midpoint. With increasing cholesterol content the maximum values of the relaxation times decrease but not in a linear fashion. The time constants display an intermediate maximum at ca. 10% to 12 mol% cholesterol. This observation is discussed in terms of a possible change in the nature of the phase transition from first-order with phase separation to a continuous second-order transition. The dependence of the relaxation amplitudes on cholesterol content gave evidence for nucleation being the rate limiting step for the transition in this particular system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00265670
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Dynamics of the formation and decay of C2(a 3II u ,v″=0) radical in a pulse discharge in methane (1986)
    Springer
    Plasma chemistry and plasma processing 6 (1986), S. 429-436 
    Details
    ISSN: 1572-8986
    Keywords: Plasma ; laser ; diagnostics ; free radicals ; kinetics
    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 The plasma of a pulse discharge (0.05 J/cm3) in methane at low pressure (200 Pa) is studied. The dynamics of formation and decay of C2(a3IIu, v″=0) is monitored using a stroboscopic laser absorption method. It was found that substantial amounts of C2, 1015 cm−3, arise with a 1-µs delay after the current pulse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00565554
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The oxidation of cobalt-chromium-titanium alloys at 1000°C (1986)
    Springer
    Oxidation of metals 26 (1986), S. 139-155 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; Co-Cr-Ti alloys ; kinetics ; scale morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cobalt-based alloys containing 3,5,10,15, and 20% Cr with 1 and 3% Ti were oxidized at 1000°C in slowly flowing oxygen gas. In general, titanium additions decreased the oxidation rate with the most pronounced effect being observed at the 10% Cr level. Titanium accelerated the formation of Cr2O3 layers at the metal-oxide interface. Faceted CrxTiyOz spinel particles were found at the metal-oxide interface which varied in composition according to microprobe results. There was no evidence of spalling on the Co-Cr-Ti alloys studied in contrast to the severe spalling normally encountered in Ni-Cr-Ti alloys. Distinct morphological differences existed on the outer CoO layer of the 1% Ti alloys in comparison to the O and 3% Ti alloys.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00664278
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Effect of scale constitution on the carburization of heat resistant steels (1986)
    Springer
    Oxidation of metals 26 (1986), S. 417-430 
    Details
    ISSN: 1573-4889
    Keywords: cyclic carburization-oxidation ; carbides ; austenite ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Several austenitic heat-resistant steels were exposed to alternating periods of carburization at 1273 K [a c= 1,po2〈10−28 atm] and oxidation at 973°K [a c≈ O,po2 = 0.2 atm]. In all cases the depth of internal carbide precipitation increased with cumulative carburization time. It was found that the carburization rates of high nickel content alloys were unaffected by intermittent oxidation cycles, whereas the low nickel, high iron content alloys experienced a reduction in carburization rate subsequent to oxidation treatment. The latter group of alloys formed external scales of chromium-rich M7C3 which were shown by sulfur tracing experiments to be gas permeable. It was concluded, therefore, that oxidation of these materials led to blockage of cracks and holes in the scales, thereby decreasing the surface carbon activity and hence the carburization rate. High nickel, low iron alloys formed external scales of chromium-rich M7C3 covered by Cr3C2. These scales were shown to have very low gas permeabilities. It was concluded that the carbon activity at the surface of these alloys was controlled by scale-alloy equilibration, and was therefore not affected by brief periods of oxidation. The pattern of carbide scale formation is qualitatively consistent with the thermodynamics of the Fe-Cr-C system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00659345
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effect of yttrium on the sulfidation behavior of Ni-Cr-Al alloys at 700°C (1986)
    Springer
    Oxidation of metals 25 (1986), S. 1-28 
    Details
    ISSN: 1573-4889
    Keywords: sulfidation ; yttrium ; duplex-sulfide scales ; lamellar sulfides ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The sulfidation of Ni-10Cr-5Al, Ni-20Cr-5Al, and Ni-50Cr-5Al, and of the same alloys containing 1% Y, was studied in 0.1 atm sulfur vapor at 700°C. The sulfidation process followed linear kinetics for all the alloys except Ni-50Cr-5Al-1Y, and possibly Ni-50Cr-5Al, which followed the parabolic law. The reaction rates decreased with increasing chromium content in alloys without yttrium, and the addition of yttrium reduced the rates by at least a factor of two for the alloys containing 10 and 20% Cr and by an order of magnitude for Ni-50Cr-5Al. Alloys containing 10 and 20% Cr (with and without yttrium) formed duplex scales consisting of an outer layer of NiS1.03 and an inner lamellar layer of a very fine mixture of Cr2S3 and A12O3 in a matrix of NiS1.03. The two alloys containing 50% Cr formed only a compact layer of Cr2S3, which was brittle and spalled during cooling. The lamellae in the duplex scales were parallel to the specimen surface and bent around corners. The lamellae were thicker than those on Ni-Al binary alloys. The lamellae were also thicker in scales on the 20% Cr alloy than on the 10% Cr alloy. The presence of yttrium refined the lamellae and increased the lamellae density near the scale/metal interface in the 10% alloy, but in the 20% Cr alloy the lammellae were thicker and more closely spaced. Platinum markers were found in the inner portion of the exterior NiS1.03 layer close to the lamellar zone. A counter-current diffusion mechanism is proposed involving outward cation diffusion and inward sulfur diffusion, although diffusion was not rate controlling for alloys containing 10 and 20% Cr. Auger analysis of scales formed on Ni-50Cr-1Y showed an even distribution of yttrium throughout the layer of Cr2S3, suggesting that some yttrium dissolved in the sulfide. The reduced sulfidation rate of samples containing yttrium is explained by the possible dissolution of yttrium as a donor. The presence of Y4+ would then decrease the concentration of interstitial chromium ions in the N-type layer of Cr2S3, which would decrease the reaction rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00807994
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Kinetic mechanisms and interaction of rat liver DNA methyltransferase with defined DNA substrates (1987)
    Springer
    Molecular and cellular biochemistry 76 (1987), S. 45-54 
    Details
    ISSN: 1573-4919
    Keywords: DNA methyltransferase ; hemimethylated DNA ; kinetics ; affinity chromatography ; (rat liver)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract DNA substrate analogs were constructed from poly(dC-dG), M13, and XP12 DNA which do not contain a mixture of types of methylation sites. These were used to distinguish different kinetic mechanisms for maintenance and de novo methylation using a highly purified rat liver DNA (cytosine-5)-methyltransferase (DMase−) preparation. De novo methylation on single (ss) and double-stranded (ds) DNA was found to obey Michaelis-Menten kinetics while methylation of hemimethylated sites showed differences depending on size of the hemimethylated region. On long stretches analogous to maintenance methylation of newly replicated DNA, saturation could not be achieved and the kinetics showed non-ideal positive cooperative kinetics, while short stretches showed non-Michaelis-Menten kinetics and rapid saturation. Two types of DMase-DNA complexes could be distinguished by means of affinity chromatography on DNA-agarose matrices and in preincubation assays. The later complex, which is engaged in methyl group turnover, exhibited enhanced stability. The competitiveness of variously configured DNAs was found to parallel the stability of complex formation, e.g., ss, hemi- and ds DNA, respectively. In studies utilizing 5-bromodeoxyuridine, the thymine analog left the basic reaction mechanisms unchanged but increased the km and S0.5 while reducing the velocity of these reactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219397
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Kinetics of oxidation of ferrous alloys by super-heated steam (1987)
    Springer
    Oxidation of metals 28 (1987), S. 237-258 
    Details
    ISSN: 1573-4889
    Keywords: Steel oxidation ; duplex scale ; steam ; activation energy ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The kinetics of the oxidation of ferrous alloys in steam (10–60 kPa) at 450–550°C have been studied by measuring both the rate of hydrogen emission and the amount of metal oxidized. Excellent agreement has been found between the amount of metal oxidized calculated from both the total mass of hydrogen produced in the reaction and the thickness of the oxide layer formed; rate constants calculated from the rate of hydrogen emission, the mass of hydrogen produced as the reaction proceeds, and the oxide formed agree within experimental error. The rate of oxidation of a 9%Cr-1%Mo alloy at 501°C was found to be independent of the partial pressure of the steam. For this alloy, the activation energy agreed with literature values obtained at higher temperatures and pressures. The effect of the chromium and silicon content on the oxidation rates is compared. The rate constants are compared with theoretical calculations, assuming that the rate is determined by diffusion of iron in the magnetite lattice. For the 9%Cr-1%Mo alloy, the parabolic rate constant and activation energy are in excellent agreement with values calculated using Wagner's theory. The experimental rate constants are greater for the alloys containing smaller amounts of chromium; diffusion of iron along magnetite grain boundaries may be the dominant mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00666721
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Kinetic studies on human lactate dehydrogenase isoenzyme-catalyzed lactate-to-pyruvate reaction (1987)
    Springer
    The protein journal 6 (1987), S. 413-429 
    Details
    ISSN: 1573-4943
    Keywords: lactate dehydrogenase isoenzymes ; lactate-to-pyruvate reaction ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In order to evaluate the functional differences that may exist in human lactate dehydrogenase (LDH) isoenzymes widely used for clinical examination the kinetic and thermodynamic properties of the lactate to pyruvate reaction that they catalize were examined. Small but significant differences in the kinetic properties of the three isoenzymes were observed. The difference in the rate constants might affect the activity measurement of the individual isoenzyme as the initial velocity for the L-P reaction catalyzed will not be the same for an equal amount of enzyme. Equilibrium constants for the overall reaction in the presence and absence of pyruvate have been determined. On the basis of transition-state theory, the standard enthalpy and free-energy changes for formation of ternary activated complex were positive, while the standard entropy change was negative. Although the standard free-energy change was the same for activation by the three isoenzymes, the enthalpy and entropy changes for the LDH-3-catalyzed reaction were different from the respective values for others. A large positive value for the free-energy change and a negative value for the entropy change indicated unfavorable production of the activated complex (K infeq. sup╪ =1.89×10-16). The enzyme appears to stabilize and retain the activated complex until it dissociates into the products.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02343339
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Generalized kinetic analysis of ion-driven cotransport systems: II. Random ligand binding as a simple explanation for non-Michaelian kinetics (1986)
    Springer
    The journal of membrane biology 90 (1986), S. 67-87 
    Details
    ISSN: 1432-1424
    Keywords: cotransport ; kinetics ; reaction kinetic model ; dual isotherm ; random binding ; slip
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Solute uptake in many cells is characterized by a series of additive Michaelis-Menten functions. Several explanations for these kinetics have been advanced: unstirred layers, transport across more than one membrane, effects of solute concentration on membrane potential, numerous carrier systems. Although each of these explanations might suffice for individual cases, none provides a comprehensive basis for interpretation of the kinetics. The most common mechanism of solute absorption involves cotransport of solute with a driver ion. A model is developed in which solute and driver ion bind randomly to a membrane-bound carrier which provides a single transmembrane pathway for transport. The kinetic properties of the model are explored with particular reference to its capacity to generate additive Michaelian functions for initial rate measurements of isotopic solute influx. In accord with previous analysis of ordered binding models (Sanders, D., Hansen, U.-P., Gradmann, D., Slayman, C.L. (1984)J. Membrane Biol. 77:123), the conventional assumption that transmembrane transit rate-limits transport has not been applied. Random binding carriers can exhibit single or multiple Michaelian kinetics in response to changing substrate concentration. These kinetics include high affinity/low velocity and low affinity/high velocity phases (so-called “dual isotherms”) which are commonly observed in plant cells. Other combinations of the Michaelis parameters can result incis-(substrate) inhibition. Despite the generality of the random binding scheme and the complexity of the underlying rate equation, a number of predictive and testable features emerge. If external driver ion concentration is saturating, single Michaelian functions always result and increasing internal substrate concentration causes uncompetitive inhibition of transport. Numerical analysis of the model in conditions thought to resemble those in many experiments demonstrates that small relative differences in a few key component rate constants of the carrier reaction cycle are instrumental in generation of dual isotherms. The random binding model makes the important prediction that the contributions of the two isotherms show opposing dependence on external concentration of driver ion as this approaches saturation. In the one case in which this dependence has been examined experimentally, the model provides a good description of the data. Charge translocation characteristics of the carrier can be determined from steady-state kinetic data on the basis of the response of substrate flux to modulation of internal driver ion concentration. The application of the model to dual isotherm kinetics is discussed in relation to “slip” models of cotransport, in which the carrier is assumed to have the capability to transport substrate alone or with the driver ion. A method for distinguishing between the two models is suggested on the basis of measurement of charge/solute transport stoichiometry as a function of external driver ion concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869687
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Effect of dose of injected hematopoietic cells on number of daughter CFU-S in splenic colonies (1986)
    Springer
    Bulletin of experimental biology and medicine 101 (1986), S. 365-366 
    Details
    ISSN: 1573-8221
    Keywords: hematopoietic stem cells ; CFU-S ; self-maintenance ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00835948
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Biotransformation of a14C-hydrogenated phenazepam analog in inbred micein vivo (1987)
    Springer
    Bulletin of experimental biology and medicine 103 (1987), S. 660-662 
    Details
    ISSN: 1573-8221
    Keywords: hydrogenated phenazepam analog ; metabolism ; kinetics ; excretion ; differences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00841831
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Diketopiperazine Formation, Hydrolysis, and Epimerization of the New Dipeptide Angiotensin-Converting Enzyme Inhibitor RS-10085 (1987)
    Springer
    Pharmaceutical research 4 (1987), S. 392-397 
    Details
    ISSN: 1573-904X
    Keywords: angiotensin-converting enzyme (ACE) inhibitor ; RS-10085 ; degradation ; kinetics ; products ; diketopiperazine ; peptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The degradation kinetics, products, and mechanisms of RS-10085(1), 2-[2-(l-ethoxycarbonyl)-3-phenylpropyl]amino-l-oxopropyl]-6,7-dimethoxy-l,2,3,4-tetrahydroisoquinoline-3-carboxylic acid(S,S,S), in aqueous solution were investigated at 40, 60, and 80°C from pH 1 to pH 13. Pseudo-first-order kinetics were observed throughout the pH range studied and the log(rate)−pH profiles reflected four kinetic processes (k o, k′o, k″o, and k OH) as well as the two pKa's of 1. Excellent (〉98%) mass balance was obtained through products 2–5. At pH 4 or below, intramolecular cyclization leading to diketopiperazine 5 accounted for greater than 93% of the observed neutral- or water-catalyzed processes (k o and k′o). At pH levels greater than 5, hydrolysis giving 2 predominated and was responsible for the observed neutral- or water-catalyzed (k″o) and specific base-catalyzed (k OH) kinetic processes. Some epimerization leading to the S,S,R drug isomer (4) was also observed at pH levels greater than 7. The relative acidity of the protons at the three chiral centers of 1 was qualitatively compared and was used to explain the observed specificity in epimerization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1016430211480
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Development of Acute Tolerance to Bumetanide: Bolus Injection Studies (1987)
    Springer
    Pharmaceutical research 4 (1987), S. 379-384 
    Details
    ISSN: 1573-904X
    Keywords: acute tolerance ; bumetanide ; kinetics ; dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Bumetanide was administered intravenously to four mongrel dogs, in a random crossover fashion, at doses of 0.05 mg/kg (I), 0.15 mg/kg (II), and 0.5 mg/kg (III) where urinary losses were replaced with lactated Ringer's solution at 1.5 ml/min (hydropenic conditions) or at a dose of 0.5 mg/kg (IV) where urinary losses were replaced with lactated Ringer's solution isovolumetrically (euvolemic conditions). Serial plasma and urine samples were assayed for bumetanide by high-performance liquid chromatography (HPLC) and for sodium by flame photometry. There were no significant differences in the pharmacokinetic parameters of bumetanide among Treatments I–IV. The dynamic parameters E max (maximum effect attributable to the drug) and s (slope factor) were not different between treatments. However, a consistent, demonstrable increase in ER50 (urinary excretion rate of drug producing 50% of E max) was observed among Treatments I (2.34 µg/min), II (3.92 µg/min), and III (6.54 µg/min); also, a significant decrease in ER50 was observed between Treatment III (6.54 µg/min) and Treatment IV (2.66 µg/min). These results show that hydration status has a marked effect on natriuretic and diuretic response and that tolerance can rapidly develop within a single intravenous dose of bumetanide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1016426110571
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    In situ SAXS investigations of isothermal crystallization in poly(TMPS) fractions (1987)
    Springer
    Colloid & polymer science 265 (1987), S. 193-205 
    Details
    ISSN: 1435-1536
    Keywords: Poly(TMPS) ; in situ ; SAXS ; crystallization ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The isothermal crystallization kinetics of poly(TMPS) has been measured by ISSAXS and results obtained for a molecular weight fraction (21,000) below the critical entanglement molecular weight (25,000) and another one above it (371,000). The SAXS intensity vs. time curves suggest that a single transformation mechanism exists. The SAXS long period is independent of crystallization time for both poly(TMPS) fractions. However the interlamellar thickness contribution to the long period is dependent upon molecular weight and crystallization temperature, increasing with temperature and molecular weight. The crystallite contribution also increases over the range studied. Both fractions exhibit a significant, but reversible decrease in thickness on cooling the sample from the crystallization temperature to room temperature and recyling again. The change is more pronounced for 371,000 specimen in keeping with its lower crystallinity. The path dependence of lamellar dimensions has significant implications in the morphological characterization of polymers annealed or crystallized at one temperature and then measured at another one.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01412707
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Migration of small hydrophobic molecules between micelles in aqueous solution (1987)
    Springer
    Colloid & polymer science 74 (1987), S. 55-63 
    Details
    ISSN: 1435-1536
    Keywords: Triplet energy transfer ; micelle ; solubilization ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Triplet energy transfer from 9-methylanthracene to azulene or guajazulene has been used to probe the migration of azulenes between micelles in aqueous solution. The migration of the hydrophobic solutes between small ionic and nonionic micelles had the temperature dependence expected for a process controlled by diffusion through the intermicellar solution, although the rate in some cases was substantially less than calculated from the Smoluchowski equation. Under conditions in which the micelles grow into large, probably rod-like structures, there are severe difficulties in separating the inter- and intramicellar deactivation processes. The intermicellar migration was enhanced under these conditions, in cetyltrimethylammonium surfactants on addition of chlorate ions, and in hexaethylene glycol dodecylether at temperatures approaching the cloud-point. The mechanism of this migration is discussed and compared with pertinent results from micelle relaxation kinetics and surfactant self-diffusion measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01191012
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Nitrogen mineralization rates in salinevs. salt-amended soils (1987)
    Springer
    Plant and soil 104 (1987), S. 13-21 
    Details
    ISSN: 1573-5036
    Keywords: ammonification ; kinetics ; nitrification ; osmotic potentials ; soluble salts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Studies were conducted to compare N mineralization rates in salt-amended nonsaline soils to naturally-occurring saline soils. NaCl, CaCl2, and Na2SO4 were added to nonsaline soils at rates that produced electrical conductivities of the saturation extracts (ECe) of 5, 10, 15, and 20 dS m−1. Saline soils with similar properties were leached to the same ECc levels. N mineralization in the Chino soil was inhibited by salt addition, particularly with sodium and calcium chlorides. In the Domino soil there was some inhibition of N mineralization with the chloride salts, but enhancement with Na2SO4 was observed. Nitrification in both soils was more sensitive to salt addition than ammonification. N mineralization occurred more slowly in both leached saline soils compared to the salt-amended soils. Leached saline soils often accumulated greater amounts of inorganic N compared to their native saline counterparts, particularly with the 5 dS m−1 Chino soil (native, 44 dS m−1) and with the 5, 10, 15 and 20 dS m−1 Domino soils (native, 32 dS m−1). Kinetic parameters were estimated by the linear least squares (LLS) and the nonlinear least squares (NLLS) methods. Generally, the LLS transformation estimated greater values of potentially mineralizable N (No) and lower rate constants (k). With the NLLS equation, No values for the leached saline soils were usually lower, and k values usually higher than in the salt-amended soils. The nonsaline controls generally had the highest No and lowest k estimates. Average LLS rate constants for the salt-amended and leached saline soils were 0.055 and 0.083 for the Chino, and 0.104 and 0.137 week−1, respectively, for the Domino soils. With the NLLS equation, average k values for the salt-amended and leached saline soils were 0.087 and 0.089 for the Chino, and 0.181 and 0.387 week−1, respectively, for the Domino soils. These results suggest that N mineralization rates obtained in salt-amended nonsaline soils may not be representative of those in naturally-occurring saline soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02370619
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    A Monte Carlo method for the simulation of kinetie models (1986)
    Springer
    Photosynthesis research 9 (1986), S. 273-283 
    Details
    ISSN: 1573-5079
    Keywords: Monte Carlo ; kinetics ; simulation ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The purpose of this note is to illustrate the feasibility of simulating kinetic systems, such as commonly encountered in photosynthesis research, using the Monte Carlo (MC) method. In this approach, chemical events are considered at the molecular level where they occur randomly and the macroscopic kinetic evolution results from averaging a large number of such events. Their repeated simulation is easily accomplished using digital computing. It is shown that the MC approach is well suited to the capabilities and resources of modern microcomputers. A software package is briefly described and discussed, allowing a simple programming of any kinetic model system and its resolution. The execution is reasonably fast and accurate; it is not subject to such instabilities as found with the conventional analytical approach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029750
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Microbial manganese(II) oxidation in the marine environment: a quantitative study (1986)
    Springer
    Biogeochemistry 2 (1986), S. 149-161 
    Details
    ISSN: 1573-515X
    Keywords: Microbial manganese(II) oxidation ; manganese(II) oxidation ; kinetics ; bacteria ; O2H2S interface 04
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract A great number of important chemical reactions that occur in the environment are microbially mediated. In order to understand the kinetics of these reactions it is necessary to develop methods to directly measure in situ reaction rates and to develop models to help elucidate the mechanisms of microbial catalysis. The oxidation of Mn(II) in a zone above the O2/H2S interface in Saanich Inlet, B.C., Canada is one such reaction. We present here a method by which in situ rates of microbial Mn(II) oxidation are measured and a model based on our experimental results to describe the general mechanism of Mn(H) oxidation. We propose a two step process in which Mn(II) is first bound by a site on the bacterial surface and then oxidized. The model is analogous to the Langmuir isotherm model for surface catalyzed gas reactions or the Michaelis-Menten model for enzyme kinetics. In situ Mn(II) oxidation rates were measured during five cruises to Saanich Inlet during the summers of 1983 and 1984. We use the model to calculate the apparent equilibrium binding constant (Ks ≈ 0.18 μM), the apparent half saturation constant for biological Mn(H) oxidation (Km = 0.22 to 0.89 μM), the maximum rate of Mn(II) oxidation (Vmax = 3.5 to 12.1 nM·h-1) and the total microbial surface binding site concentration (Σ E ≈ 51 nM). Vmax for Mn(II) oxidation agrees with the rates calculated from the value of the flux of Mn(II) to the oxidizing zone using the Mn(II) gradient and estimates of the eddy diffusion coefficient. This consistancy verifies our methodology and indicates that the rate of Mn(II) oxidation is nearly equal to the (Vmax for the reaction. We conclude that in this environment the Mn(II) oxidation rate is more a function of the total number of surface binding sites than the Mn(H) concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02180192
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Phospholipid transfer proteins: Mechanism of action (1986)
    Springer
    Journal of bioenergetics and biomembranes 18 (1986), S. 71-91 
    Details
    ISSN: 1573-6881
    Keywords: Phospholipid transfer protein ; phosphatidylcholine ; phosphatidyllinositol ; exchange ; net transfer ; lipid-protein interactions ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Phospholipid transfer proteins are generally localized in the cytosolic fraction of cells and are capable of catalyzing the flux of phospholipid molecules among membranes. Artificial membranes also participate in protein-catalyzed phospholipid movements. In this review the major phospholipid transfer proteins are discussed with respect to their phospholipid substrate specificity and the contributions of membrane physical properties to this process. The phenomenon of net transfer of phospholipids is described. The use of various kinetic approaches to the study of these catalysts is reviewed. A detailed consideration of the distinct phospholipid binding and membrane interaction domains of one phospholipid transfer protein is presented. Finally, some recent applications of phospholipid transfer proteins to the examination of membrane structure and function and further directions for the continued research activity with this class of proteins are summarized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00743477
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Synthesis of molecular sieve AlPO4-12 (1986)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 4 (1986), S. 325-331 
    Details
    ISSN: 1573-1111
    Keywords: Aluminophosphate ; molecular sieves ; crystallization ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A member of the novel family of crystalline microporous aluminophosphates, AlPO4-12, was synthesized by hydrothermal crystallization using different aluminum-containing compounds. Three new crystalline phases were obtained by varying the composition of the reaction mixture. The effect of the synthesis conditions on the hudrothermal process and the kinetics of crystallization are discussed. The apparent activation energies obtained for AlPO4-12 are 20.9 and 14.6 kcal/mol for nucleation and crystallization, respectively. The adsorption isotherms of one AlPO4-12 product were measured.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656159
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    ESR spectroscopic study and kinetic discussion of the disproportionation reaction of nitrogen monoxide on CaHY-type zeolite (1987)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 385-395 
    Details
    ISSN: 1573-1111
    Keywords: Nitrogen monoxide ; ESR spectroscopy ; disproportionation reaction ; CaHY-type zeclite ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An ESR spectroscopic study of adsorbed NO on CaHY-type zeolite was carried out and the kinetics are discussed on the basis of a mechanistic model of the disproportionation reaction. An amount of NO less than the amount of Ca2+ distributed in Site II of the faujasite structure was admitted onto the sample maintained at 373 K. ESR spectra were recorded at room temperature. The spectra consisted of well-resolved signals. It is proposed that NO molecules on CaHY-type zeolite have two kinds of adsorption patterns. The initial formation of N2O may be expressed by the following reactions: $$[ ] + NO\mathop \rightleftharpoons \limits_{}^{K_1 } [NO],[NO] + NO\mathop \rightleftarrows \limits_{\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\leftharpoonup}$}} {k} _2 }^{\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\rightharpoonup}$}} {K} _2 } [N_2 O_2 ],[N_2 O_2 ] + NO\mathop \to \limits_{}^{\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\rightharpoonup}$}} {K} _3 } [NO_2 ] + N_2 O,$$ where [], [NO] and [N2O2] denote vacant adsorption, NO adsorption, and N2O2 adsorption sites, respectively. A rate equation for N2O appearance (α) has been derived by a steady state approximation: $$\alpha = \frac{{\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\rightharpoonup}$}} {k} _3 K_1 K_2 P^3 }}{{1 + (K_1 + \overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\rightharpoonup}$}} {k} _3 /\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\leftharpoonup}$}} {k} _2 )P + K_1 (K_2 + \overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\rightharpoonup}$}} {k} _3 /\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\leftharpoonup}$}} {k} _2 )P^2 }},$$ WhereP is the pressure of NO. The rate equation was used to explain the kinetic results of the disproportionation of NO.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00665372
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Inclusion of rhodamine B byβ-cyclodextrin. An equilibrium and kinetic spectrophotometric study (1987)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 709-716 
    Details
    ISSN: 1573-1111
    Keywords: Cyclodextrin ; rhodamine B ; equilibrium ; kinetics ; temperature-jump
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A UV/visible spectrophotometric temperature-jump study of the inclusion of the rhodamine B zwitterion (RB) by β-cyclodextrin (βCD) to form a 1:1 complex (RB·βCD) in aqueous 1.00 mol dm−3 NaCl at pH 6.40 and 298.2 K yields:k 1=(1.3±0.2)×108 dm3 mol−1 s−1,k −1=(2.2±0.5)×104 s−1, andK 1=(5.9±2.3)×103 dm3 mol−1 for the equilibrium: $${\text{RB + }}\beta {\text{CD}}{\text{RB}} \cdot \beta {\text{CD}} K_1 $$ Under the same conditions the dimerization of RB: $${\text{2}} {\text{RB}}({\text{RB}})_2 K_d $$ is characterized byK d =(1.8±1.0)×103 dm3 mol−1. The interaction of RB with αCD and γCD is weaker than with βCD, and is discussed in terms of the relative sizes of RB and the cyclodextrin annulus. Comparisons are made with the inclusions of other dyes by cyclodextrins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656590
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Methoxy formation in the reaction of CH3O2 radicals with NO (1986)
    Springer
    Journal of atmospheric chemistry 4 (1986), S. 241-251 
    Details
    ISSN: 1573-0662
    Keywords: Free radical reactions ; kinetics ; product distribution ; methane oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Formation of methoxy (CH3O) radicals in the reaction (1) CH3O2+NO→CH3O+NO2 at 298 K has been observed directly using time resolved LIF. The branching ratio % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqOXdyMaae% 4qaiaabIeadaWgaaWcbaGaae4maaqabaGccaqGpbGaaeiiaiaabIca% ieqacaWF9aGaa8hiaiaa-nbicaWFGaGaeuiLdqKaai4waiaaboeaca% qGibWaaSbaaSqaaiaabodaaeqaaOGaae4taiaac2facaWFVaGaeuiL% dqKaai4waiaaboeacaqGibWaaSbaaSqaaiaabodaaeqaaOGaae4tam% aaBaaaleaacaqGYaaabeaakiaac2facaqGPaaaaa!4E31!\[\phi {\rm{CH}}_{\rm{3}} {\rm{O (}} = -- \Delta [{\rm{CH}}_{\rm{3}} {\rm{O}}]/\Delta [{\rm{CH}}_{\rm{3}} {\rm{O}}_{\rm{2}} ]{\rm{)}}\] has been determined by quantitative cw-UV-laser absorption at 257 nm of CH3O2 and CH3ONO, the product of the consecutive methoxy trapping reaction (2) % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaae4qaiaabI% eadaWgaaWcbaGaae4maaqabaGccaqGpbacbeGaa83kaiaa-bcaieaa% caGFobGaa43taiaa+bcacaGFOaGaa83kaiaa+1eacaGFPaGaa4hiai% abgkziUkaabccacaqGdbGaaeisamaaBaaaleaacaqGZaaabeaakiaa% b+eacaqGGaGaaeOtaiaab+eacaqGGaGaa4hkaiaa-TcacaGFnbGaa4% xkaiaa+5cacaGFGaGaa4hiaiabeA8aMnaaBaaajqwaacqaaiaaboea% caqGibWaaSbaaKazcaiabaGaae4maaqabaqcKfaGaiaab+eaaSqaba% aaaa!55AC!\[{\rm{CH}}_{\rm{3}} {\rm{O}} + NO ( + M) \to {\rm{ CH}}_{\rm{3}} {\rm{O NO }}( + M). \phi _{{\rm{CH}}_{\rm{3}} {\rm{O}}} \] is found to be (1.0±0.2). The rate constant k 1 is (7±2) 10-12 cm3/molecule · s in good agreement with previous results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00052003
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    A simulation model of sulfur transformations in forested Spodosols (1986)
    Springer
    Biogeochemistry 2 (1986), S. 313-328 
    Details
    ISSN: 1573-515X
    Keywords: soil organic sulfur ; mineralization ; reaction rates ; kinetics ; immobilization ; soil adsorption ; sulfate ; first-order ; michaelis-menten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Transformations of organic and inorganic S in two forested Spodosols from the Hubbard Brook Experimental Forest, New Hampshire and the Huntington Forest in the Adirondack Mts. of New York were investigated using laboratory35SO4 2- incorporation experiments. Sulfur transformations were modeled as a set of three reversible, first-order reactions in which soluble SO 4 2- is converted to adsorbed SO 4 2- , ester sulfate and carbon-bonded S. Reaction rate contants for35SO 4 2- adsorption/desorption and immobilization reactions involving ester sulfate and carbon-bonded S were determined using a fifth order Runge-Kutta-Fehlberg integration routine combined with least squares fitting. Model simulations were able to account for over 93% of the variation in the distribution of35S in S fractions. A hypothetical application of immobilization rate constants to field situations at the Hubbard Brook Experimental Forest suggests that large quantities of S cycle through organic forms in Northern Hardwood Forest Ecosystems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02180323
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    The attachment to human buccal epithelial cells by Candida albicans: An in vitro kinetic study using concanavalin A (1987)
    Springer
    Mycopathologia 98 (1987), S. 179-184 
    Details
    ISSN: 1573-0832
    Keywords: adhesion ; C. albicans ; kinetics ; concanavalin A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The early in vitro kinetics of Candida albicans attachment to human buccal epithelial cells was studied with the aid of an adhesion assay and solutions of concanavalin A (Con A), a lectin which is capable of inhibiting yeast adhesion. Various saccharides and putative receptor analogues were also tested. Solutions of each single reagent were added to tubes containing aliquots of mucosal cells and germinated yeasts at the beginning of a 1-hour incubation period (time O) or at 10 minute intervals during the assay. The number of yeasts attached to 200 mucosal cells was subsequently determined microscopically. Yeast adhesion remained constant following addition of phosphate-buffered saline (PBS) at time 0 or at any time thereafter. However, addition of Con A at 0, 10 or 20 minutes of incubation decreased adhesion significantly to 38%, 45% and 63% of control values. This inhibitory effect dwindled as time of incubation prior to lectin addition increased and Con A could not inhibit adhesion significantly after twenty minutes. Results obtained with Con A using live germinated yeasts were similar to those obtained with formalin-killed C. albicans. The other reagents tested failed to decrease adhesion significantly. These included the putative receptor analogues fibronectin, N-acetyl-d-glucosamine and d-galactose, and several non-specific saccharides such as α-d-methylglucopyranoside, d-ribose and d-xylose. It is suggested that in vitro attachment to human mucosal cells by C. albicans is inhibitable up to a defined point in time by a lectin with affinity for mannosecontaining surface moieties, but becomes non-reversible thereafter. This experimentally-observed irreversibility is independent of yeast cell viability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00437653
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...