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  • Springer  (79)
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  • Chemistry and Pharmacology  (79)
  • 1
    Electronic Resource
    Electronic Resource
    Studies on the Complexation Behavior of Thorium(IV). 1. Hydrolysis Equilibria (2000)
    Springer
    Journal of solution chemistry 29 (2000), S. 63-86 
    Details
    ISSN: 1572-8927
    Keywords: Thorium ; hydrolysis ; potentiometry ; solvent extraction ; temperature ; thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability constants of thorium(IV) hydrolysis species have been measured at15, 25, and 35°C (in 1.0 mol dm−3 NaClO4) using both potentiometry and solventextraction. The results indicate the presence of the monomeric speciesTh(OH)3+, Th(OH)2+ 2, Th(OH)+ 3, and Th(OH)4, in addition to the polymericspecies Th4(OH)8+ 8 and Th6(OH)9+ 15. The polymeric species were found to beimportant, although the total thorium concentration was limited to 0.01–0.1mmol-dm−3. The solvent extraction measurements required the use of acetylacetone.As such, the stability constants of thorium(IV) with acetylacetone were alsomeasured using both potentiometry and solvent extraction. All logarithms of thestability constants were found to be linear functions of the reciprocal absolutetemperature indicating that ΔH o and ΔSo of reaction are both independent oftemperature (over the temperature range examined in the study).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005166517699
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  • 2
    Electronic Resource
    Electronic Resource
    Conductivity of Dilute Aqueous Electrolyte Solutions at High Temperatures and Pressures Using a Flow Cell (2000)
    Springer
    Journal of solution chemistry 29 (2000), S. 217-235 
    Details
    ISSN: 1572-8927
    Keywords: Flow-through cell ; conductivity ; electrolyte ; ion association ; temperature ; pressure ; LiCl ; NaCl ; KCl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A flow-through electrical conductance cell was assembled in order to measuremolar conductances of dilute aqueous electrolytes with a high degree of accuracyat high temperatures and pressures. The design of the cell is based on the conceptdeveloped at the University of Delaware and built in 1995, with modificationsthat will allow the cell to operate at much higher temperatures (to 600°C) andpressures (to 300 MPa). At present, the cell has been tested successfully bymeasuring aqueous (10−4-10−3 mol-kg−1) solutions of LiCl, NaCl, and KCl attemperatures 25–410°C and pressures 9.8–33 MPa. The results are in goodagreement with reported values, including those measured with the Delawareflow-through cell. These new results are also complementary to our previousresults, which were measured with a static high-pressure cell. Measurements attemperatures near the critical point of water (374°C, 22.1 MPa) require the useof lower solution concentrations that were unachievable in the past with thestatic cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005146332605
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  • 3
    Electronic Resource
    Electronic Resource
    On the Development of the Temperature Concept (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 1081-1091 
    Details
    ISSN: 1572-8943
    Keywords: second law of thermodynamics ; temperature ; thermometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A brief outline of the history of development of the temperature concept in physics is given. Simultaneously, some persisting imperfections in the conceptual basis of classical thermodynamics closely related to the first and the second law of thermodynamics are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010196716770
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of Temperature and Photoperiod on Phytotoxic Root Exudates of Cucumber (Cucumis sativus) in Hydroponic Culture (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 1953-1967 
    Details
    ISSN: 1573-1561
    Keywords: Allelopathy ; autotoxicity ; activated charcoal ; cucumber ; Cucumis sativus L ; 2,4-dichlorobenzoic acid ; organic acids ; photoperiod ; temperature ; root exudates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In order to elucidate the effects of temperature and photoperiod on the quality and quantity of plant root exudates, a Japanese cucumber (Cucumis sativus, cv. Shougoin-Aonaga-Fushinari) was grown hydroponically in growth chambers under controlled temperature and photoperiod conditions with or without the addition of activated charcoal (AC) to the nutrient solutions. Fresh AC was used to trap the organic compounds exuded from cucumber roots every two weeks. Cucumber plants without AC were severely retarded in root growth and in the accumulation of dry matter, especially at high temperature and long photoperiod, compared to those with AC. The growth inhibitors, adsorbed on the AC or accumulated in the nutrient solution without AC, were extracted by organic solvents and analyzed by GC-MS. Benzoic acid and its derivatives, cinnamic acid derivatives, and fatty acids were identified. The rate of root exudation in vegetative and reproductive stages for some of these organic acids increased with the elevation of temperature and the elongation of photoperiod, and the mean rate was two or more times higher than the minimum exudation at low temperature with short photoperiod. Some of the identified compounds significantly inhibited the germination and/or root growth of lettuce and cucumber.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005509110317
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  • 5
    Electronic Resource
    Electronic Resource
    Differences in the Denaturation Behavior of Ribonuclease A Induced by Temperature and Guanidine Hydrochloride (2000)
    Springer
    The protein journal 19 (2000), S. 345-352 
    Details
    ISSN: 1573-4943
    Keywords: Ribonuclease A ; limited proteolysis ; temperature ; guanidine hydrochloride ; unfolding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Moderate temperatures or low concentrations of denaturants diminish the catalytic activity of some enzymes before spectroscopic methods indicate protein unfolding. To discriminate between possible reasons for the inactivation of ribonuclease A, we investigated the influence of temperature and guanidine hydrochloride on its proteolytic susceptibility to proteinase K by determining the proteolytic rate constants and fragment patterns. The results were related to changes of activity and spectroscopic properties of ribonuclease A. With thermal denaturation, the changes in activity and in the rate constants of proteolytic degradation coincide and occur slightly before the spectroscopically observable transition. In the case of guanidine hydrochloride-induced denaturation, however, proteolytic resistance of ribonuclease A initially increases accompanied by a drastic activity decrease far before unfolding of the protein is detected by spectroscopy or proteolysis. In addition to ionic effects, a tightening of the protein structure at low guanidine hydrochloride concentrations is suggested to be responsible for ribonuclease A inactivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026479212350
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  • 6
    Electronic Resource
    Electronic Resource
    Will changes in soil organic carbon act as a positive or negative feedback on global warming? (2000)
    Springer
    Biogeochemistry 48 (2000), S. 21-51 
    Details
    ISSN: 1573-515X
    Keywords: carbon cycle ; decomposition ; global change ; soil organic matter ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The world's soils contain about 1500 Gt of organic carbon to a depth of 1m and a further 900 Gt from 1--2m. A change of total soil organic carbon by just 10% would thus be equivalent to all the anthropogenic CO2 emitted over 30 years. Warming is likely to increase both the rate of decomposition and net primary production (NPP), with a fraction of NPP forming new organic carbon. Evidence from various sources can be used to assess whether NPP or the rate of decomposition has the greater temperature sensitivity, and, hence, whether warming is likely to lead to an increase or decrease in soil organic carbon. Evidence is reviewed from laboratory-based incubations, field measurements of organic carbon storage, carbon isotope ratios and soil respiration with either naturally varying temperatures or after experimentally increasing soil temperatures. Estimates of terrestrial carbon stored at the Last Glacial Maximum are also reviewed. The review concludes that the temperature dependence of organic matter decomposition can be best described as: d(T) = exp[3.36 (T − 40)/(T + 31.79)] where d(T) is the normalised decomposition rate at temperature T (in °C). In this equation, decomposition rate is normalised to ‘1’ at 40 °C. The review concludes by simulating the likely changes in soil organic carbon with warming. In summary, it appears likely that warming will have the effect of reducing soil organic carbon by stimulating decomposition rates more than NPP. However, increasing CO2 is likely to simultaneously have the effect of increasing soil organic carbon through increases in NPP. Any changes are also likely to be very slow. The net effect of changes in soil organic carbon on atmospheric CO2 loading over the next decades to centuries is, therefore, likely to be small.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006238902976
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  • 7
    Electronic Resource
    Electronic Resource
    Seasonal Variation in Amount and Composition of Monoterpenes Emitted by Young Pinus pinea Trees – Implications for Emission Modeling (2000)
    Springer
    Journal of atmospheric chemistry 35 (2000), S. 77-99 
    Details
    ISSN: 1573-0662
    Keywords: monoterpene emission ; Mediterranean pine ; seasonal variation ; light ; temperature ; algorithms ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Current inventories of terpenes released from vegetation consider only the short-term influences of light and temperature on emissions to simulate temporal variation during the year. We studied whole canopy emissions from young Pinus pinea during a 15-month enclosure in greenhouse chambers and examined data for other long-term influences. Mean daytime emission rates strongly increased during spring, reached an annual maximum of ≈ 200 pmol m−2 total needle area s−1 (1.1 μg g−1 leaf dry weight h−1) between mid June and mid August, strongly declined in fall and reached an annual minimum of ≈ 1 pmol m−2 s−1 (0.006 μg g−1 h−1) between January and February. Normalization to standard temperature and light conditions did not change the annual time course of emissions, but reduced summer to winter ratio from a factor of 200 to about 45. Seasonal variation was characterized also by changes in terpene composition: among the six main compounds, three (t-β-ocimene, linalool, 1.8-cineol) were exclusively emitted during sunlit hours in the main vegetation period, whereas the other (limonene, α-pinene, myrcene) were emitted day and night and throughout the seasons. The results suggest that different terpene sources in P. pinea foliage exist and that a great part of the annual emission course observed here results from seasonal influences on these sources. A global model to simulate plant emissions is proposed, which accounts for seasonal influences on emissions in addition to the short-term effects of temperature and light. The model is tested on field data and discussed for its general application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006233010748
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  • 8
    Electronic Resource
    Electronic Resource
    Temperature Effects on Soil Mineralization of Polylactic Acid Plastic in Laboratory Respirometers (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 101-108 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; respirometers ; soil degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A respirometric system was used to analyze the biodegradation of high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films in soil under laboratory conditions. The respirometric system consisted of air-conditioning pretraps, a soil reactor, and a carbon dioxide (CO2) posttrap. A 200-g homogeneous soil mixture of all-purpose potting soil : manure soil : sand [1 : 1 : 1 (w/w)] and 1.5 g of PLA plastic films in 1 × 1-cm2 squares was added to each bottle. The respirometers were placed in a 28, 40, or 55°C water bath for 182 days. Treatments (three replicates) included native corn starch (positive control), polyethylene (Glad Cling Wrap; negative control), and three PLA films: Ca-I (Cargill Dow Polymers LLC, monolayer), GII (Cargill Dow Polymers LLC, Generation II), and Ch-I (Chronopol; monolayer). The degree of polymer mineralization was indicated by the cumulative CO2 liberated from each respirometer. The initial average mineralization rate and total percentage mineralized of the PLA plastic films at 28, 40, and 55°C was 24.3, 41.5, and 76.9 mg/day with a 27, 45, and 70% carbon loss, respectively. No decrease in soil pH was observed after 182 days of mineralization. Hence, increase in soil temperature drastically enhanced the biodegradation of PLA plastic films in soil under laboratory conditions (P 〈 0.0001).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021812418325
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  • 9
    Electronic Resource
    Electronic Resource
    Effects of Temperature and Relative Humidity on Polylactic Acid Plastic Degradation (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 83-92 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; relative humidity ; degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Three high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films from Chronopol (Ch-I) and Cargill Dow Polymers (GII and Ca-I) were analyzed for their degradation under various temperature and relative humidity (RH) conditions. Two sets of plastic films, each containing 11 samples, were randomly hung in a temperature/humidity-controlled chamber by means of plastic-coated paper clips. The tested conditions were 28, 40, and 55°C at 50 and 100% RH, respectively, and 55°C at 10% RH. The three tested PLA films started to lose their tensile properties when their weight-average molecular weight (M w) was in the range of 50,000 to 75,000 g mol−1. The average degradation rate of Ch-I, GII, and Ca-I was 28,931, 27,361, and 63,025 M w/week, respectively. Hence, GII had a faster degradation rate than Ch-I and Ca-I under all tested conditions. The degradation rate of PLA plastics was enhanced by the increase in temperature and relative humidity. This trend was observed in all three PLA plastics (Ca-I, GII, and Ch-I). Of the three tested films, Ch-I was the first to lose its mechanical properties, whereas Ca-I demonstrated the slowest loss, with mechanical properties under all tested conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021808317416
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  • 10
    Electronic Resource
    Electronic Resource
    Electrochemical synthesis of cupric oxide powder Part II: Process conditions (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 81-85 
    Details
    ISSN: 1572-8838
    Keywords: cupric oxide ; powder ; current density ; temperature ; sodium sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Electrosynthesis of cupric oxide powder was carried out on a laboratory scale in an electrochemical cell under various experimental conditions. The electrolysis was appraised in terms of the particle size of the cupric oxide product and the anodic dissolution of the copper electrode. Using a previously determined pH value of 7.50, the other optimum electrolysis operating conditions established were a current density of 4000Am−2, temperature of 353K, and Na2SO4 concentration of 0.5m. The optimum values of current efficiency, cell voltage and specific energy consumption for the electrochemical synthesis of cupric oxide powder were determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003464914657
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  • 11
    Electronic Resource
    Electronic Resource
    Sulfate solubility algorithms for CaSO4–NaCl–H2O and Na2SO4–NaCl–H2O in chlor alkali brine at 25, 65, 75 and 85 ∘C (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 525-528 
    Details
    ISSN: 1572-8838
    Keywords: brine ; chlor-alkali cells ; solubility ; sulfate ions ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026405806916
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  • 12
    Electronic Resource
    Electronic Resource
    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m- 2 yr-1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m-2 yr-1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006061814731
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  • 13
    Electronic Resource
    Electronic Resource
    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m−2 yr−1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m−2 yr−1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00992979
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  • 14
    Electronic Resource
    Electronic Resource
    Voltammetric Analysis of Iodide and Diffusion Coefficients Between 25 and 85°C (1998)
    Springer
    Journal of solution chemistry 27 (1998), S. 373-393 
    Details
    ISSN: 1572-8927
    Keywords: Iodide ; voltammetry ; diffusion coefficients ; temperature ; Stokes–Einstein equation ; solvation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The oxidation wave of iodide in 0.075 mol-L−1 H2SO4 was analyzed at 25, 40, 55, 70, and 85°C. The reversibility of the I2/I− system was checked using logarithmic transforms, half-wave potentials, and by studying I −1 = f(ω−1/2). The limiting currents obtained enabled us to determine the diffusion coefficient of I− using Newman's equation. These experimental results were compared with Nernst's limiting values. The Stokes–Einstein equation is not verified. Hydration numbers for I− at different temperatures were established. An empirical equation is proposed to predict the evolution of diffusion coefficients in a sulfuric acid medium with temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022679716395
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  • 15
    Electronic Resource
    Electronic Resource
    Thermodynamics of Polyvinylacetate from 0 to 350 K (1998)
    Springer
    Journal of thermal analysis and calorimetry 54 (1998), S. 731-740 
    Details
    ISSN: 1572-8943
    Keywords: enthalpy ; entropy ; Gibbs energy ; heat capacity ; limiting polymerization temperature ; polyvinylacetate ; temperature ; thermodynamics of polymerization ; vinyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The temperature dependence of the heat capacity of vinyl acetate in the range 13 to 330 K and of polyvinylacetate between 4.9 and 330 K was determined by adiabatic vacuum calorimetry with an error of about 0.2%. Temperatures and enthalpies of physical transitions were measured. From the data obtained, the thermodynamic characteristics of melting of vinyl acetate and parameters of glass transition and glassy state of the monomer and polymer were calculated. The thermodynamic functions Ho(T)-Ho(0), So(T), Go(T)-Ho(0) were estimated for both materials from 0 to 350 K. The results of calculation and the literature value of enthalpy of bulk polymerization of vinyl acetate at T=350 K were used for the estimation of the thermodynamic parameters of its polymerization process ΔHpol o, ΔSpol o, ΔGpol oin the interval 0 to 350 K. A ceiling limiting temperature of polymerization Tceil owas evaluated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010179517532
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  • 16
    Electronic Resource
    Electronic Resource
    High temperature conjugation of proteins with carbohydrates (1998)
    Springer
    Glycoconjugate journal 15 (1998), S. 131-138 
    Details
    ISSN: 1573-4986
    Keywords: protein ; conjugate ; carbohydrate ; lyophilization ; vaccine ; temperature ; heating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new procedure was used to conjugate lactose and dextran with BSA without using coupling or activating reagents. The method is simple, rapid and cheap. Reducing sugars covalently bind to proteins when lyophilized together and briefly heated to a high temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007067513242
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  • 17
    Electronic Resource
    Electronic Resource
    Integrated Pharmacokinetic–Pharmacodynamic Model for Acetaminophen, Ibuprofen, and Placebo Antipyresis in Children (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 559-579 
    Details
    ISSN: 1573-8744
    Keywords: acetaminophen ; age ; antipyretic ; fever ; ibuprofen ; pediatrics ; pharmacokinetics ; pharmacodynamics ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A descriptive profile for antipyretic drug action has been documented for children. However, a linked pharmacokinetic–pharmacodynamic (PK/PD) model is central to the understanding of antipyretic drug action in febrile children. This was examined for previously reported data from 178 febrile children who received a single oral dose of acetaminophen (APAP) (12.5 mg/kg), ibuprofen (IBU) (5 or 10 mg/kg), or placebo. Rectal temperatures and plasma levels (μg/ml) of APAP and IBU were measured for up to 12 hr after drug administration. Nonlinear regression analyses were applied to these measurements and yielded simultaneous solutions of an integrated one-compartment PK, link, and SigmoidEmax effect model in 102/153 febrile children given APAP or IBU. The PK parameters (tlag ,ka , β,T1 / 2β ,AUC0–∞ ,Vd/F,andClp/F) were not different than those reported previously, except the APAPka was significantly lower. The link component yieldedkeo s of 0.58±0.06 (X±SE), 0.70±0.11 and 0.57 ± 0.11 hr -1 for APAP, IBU05, and IBU10, respectively: the SigmoidEmax component yieldedEC50 s (μg/ml) and sigmoidicity (γ) of 4.63±0.39 and 3.98±0.42 for APAP, 11.33±1.35 and 3.97±0.58 for IBU05 and 12.83±1.89 and 4.27±0.63 for IBU10. On visual inspection of the efficacy–time profiles of the febrile children, a number of them had an apparent linear function (slope; Δ°C/hr) and/or a sinusoidal cyclic function “confounding” standard approaches to PD analysis. Thus, the temperature profiles of 91/102 children given APAP or IBU required the addition of a slope (Δ°C/hr) and/or a sinusoidal cyclic function to the SigmoidEmax component to fit the data satisfactorily. All 22 children given a placebo also required a slope and/or a cyclic function in their PD model. The residual Δ°Cs (observed-predicted) of the placebo group were not significantly different from 0. Thus, no placebo antipyretic effect was observed. Dose dependency of IBUAUC0–∞ was confirmed; doubling the dose from 5 to 10 mg/kg increased theAUC0→∞ by only 1.5-fold. The confounding effect of initial temperature (Tempi ) on antipyretic efficacy in all treatment groups except placebo was also confirmed to expose nonlinear pharmacodynamics. A significant (p=0.03) contribution ofTempi (but not age) on the value of the slope function was found. There was no consistent effect of age orTempi , on the cyclic component of the integrated model of antipyresis. In addition, a multiple linear relationship of age andTempi was observed with a large number of the PK, link, and PD variables in those who received IBU. Dose, age, andTempi interacted with β in a significant multiple linear relationship withAUC0–∞ . The effects of IBU dose, age, andTempi are pervasive and cascade down the chain of events leading to the PD response. The etiology of pyresis may create the slope function, the magnitude of which may be partially due to the underlying disease. In some cases, the cyclic function may be explained by temperature regulation. Regardless of their cause, both confound analysis of drug action and make the simple, unmodified SigmoidEMax effect model less than satisfactory for interpretation of antipyretic drug effects. The influence of Tempi on the magnitude of antipyretic drug response is also a finding with major impact on PD investigations of antipyretic medications. In children receiving IBU, dose and age are also confounders, in addition toTempi . A multiplicity of covariables must be taken into account when developing appropriate dosing regimens for these antipyretics in febrile children.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1023225217108
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  • 18
    Electronic Resource
    Electronic Resource
    Hysteresis in the temperature response of carbon dioxide and methane production in peat soils (1998)
    Springer
    Biogeochemistry 43 (1998), S. 253-272 
    Details
    ISSN: 1573-515X
    Keywords: carbon dioxide ; hysteresis ; methane ; peat ; temperature ; wetlands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The ability to predict the effects of climate change on trace gas fluxes requires a knowledge of microbial temperature responses. However, the response of a microbial community to temperature in a given substrate may be complicated by its thermal history. To examine the effect of sequentially changing temperature on methane and carbon dioxide production in different peat types, we incubated anaerobic peat samples from 3 types of northern peatlands, a bog, a sedge fen and a cedar swamp, in both rising and falling temperature regimes. Graphic and statistical comparisons of the different temperature regimes suggest hysteresis in microbial response to temperature, although the absolute rates at any given temperature often did not differ. Where regressions for temperature response (Arrhenius plots) were significant, they generally differed between temperature regimes. The greatest differences among treatments occurred during the first half of the 40-d incubation. Increases in carbon dioxide production were similar across all peat types, but methanogenesis varied widely: methane production was uniformly low in the bog peat but increased sharply with temperature in the other two peat types. The complicating effect of history or chronology on substrate responses to environmental stimuli may restrain our ability to model the responses of complex systems to changing conditions.
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    URL: http://dx.doi.org/10.1023/A:1006097808262
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    Effect of temperature on performanceof LaNi4.76Sn0.24 metal hydride electrode’ (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1328-1332 
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    ISSN: 1572-8838
    Keywords: metal hydride ; capacity ; temperature ; performance ; enthalpy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The effect of temperature on the performance of a LaNi4.76Sn0.24 metal hydride electrode was investigated in the temperature range of 0 to 50°C. The electrode showed a maximum discharge capacity at 25°C. The total resistance increases with a decrease of temperature from 50°C to 0°C. The apparent activation enthalpies at different states of charge were determined by evaluating the polarization resistance at different temperatures. It was found that the apparent activation enthalpy is an indicator of the relative reaction rate of the charge-transfer reaction and hydrogen absorption.
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    URL: http://dx.doi.org/10.1023/A:1018460709968
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    Comparative studies on some analytical methods (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 857-862 
    Details
    ISSN: 1572-8943
    Keywords: analytical methods ; kinetics ; powder milk ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.
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    URL: http://dx.doi.org/10.1007/BF01996770
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    Micellization of triblock copoly(ethyleneoxide/tetrahydrofuran/ethylene oxide) (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 467-473 
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    ISSN: 1435-1536
    Keywords: Key words Block copolymers ; micelle ; temperature
    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 association behaviour of triblock copoly(ethylene oxide/tetrahydrofuran/ethylene oxide), in particular E100T27E100, in aqueous solutions has been investigated by means of static and dynamic light scattering, nuclear magnetic reso-nance (NMR) and surface tension techniques. On raising the polymer concentration at room temperature, the copolymer aggregates to form micelles with an aggregation number of about 105 (R G, mic≈15 nm and R H, mic≈13 nm, as revealed by light scattering and FT-PGSE NMR measurements, respectively). The micelles are kinetically quite stable, the micellar lifetime is shown to be more than 1 h. The residence time of a single unimer in a micelle is more than 140 ms. The apparent radius of gyration R G, mic is fairly independent of concentration, but large effects are observed on varying the temperature. Raising the temperature initially results in an increase of the apparent micellar size, followed by a maximum at an intermediate temperature (≈45 °C). At higher temperatures a contraction of the micelles is observed. The shape of the micelles also appear to vary in this temperature interval. The interactions responsible for these phenomena are discussed in terms of, e.g., the temperature-dependent solubility of the alkylene oxide segments in water and polydispersity effects.
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    URL: http://dx.doi.org/10.1007/s003960050105
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    Effects of air pollutant-temperature interactions on mineral-N dynamics and cation leaching in reciplicate forest soil transplantation experiments (1997)
    Springer
    Biogeochemistry 39 (1997), S. 295-326 
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    ISSN: 1573-515X
    Keywords: acidification ; aluminium ; Arrhenius’ law ; calcium ; cation leaching ; climate ; ion equilibrium ; forest soil ; N-cycle ; N-deposition ; nitrification ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Increased emissions of nitrogen compounds have led to atmosphericdeposition to forest soils exceeding critical loads of N overlarge parts of Europe. To determine whether the chemistry offorest soils responds to changes in throughfall chemistry, intactsoil columns were reciprocally transplanted between sites, withdifferent physical conditions, across a gradient of N and Sdeposition in Europe. The transfer of a single soil to the various sites affected itsnet nitrification. This was not simply due to the nitrificationof different levels of N deposition but was explained bydifferences in physical climates which influenced mineralizationrates. Variation in the amount of net nitrification between soiltypes at a specific site were explained largely by soil pH. Within a site all soil types showed similar trends in netnitrification over time. Seasonal changes in net nitrificationcorresponds to oscillations in temperature but variable time lagshad to be introduced to explain the relationships. WithArrhenius‘ law it was possible to approximate gross nitrificationas a function of temperature. Gross nitrification equalled netnitrification after adaptation of the microbial community oftransplanted soils to the new conditions. Time lags, andunderestimates of gross nitrification in autumn, were assumed tobe the result of increased NH 4 + availability due either tochanges in the relative rates of gross and net N transformationsor to altered soil fauna-microbial interactions combined withimproved moisture conditions. Losses of NO 3 - were associated with Ca2+and Mg2+ in non-acidified soil types and with losses ofAl3+ in the acidified soils. For single soils the ionequilibrium equation of Gaines-Thomas provided a useful approximationof Al3+ concentrations in the soil solution as a functionof the concentration of Ca2+. The between site deviationsfrom this predicted equilibrium, which existed for single soils, couldbe explained by differences in throughfall chemistry which affectedthe total ionic strength of the soil solution. The approach of reciprocally transferring soil columnshighlighted the importance of throughfall chemistry, interactingwith the effect of changes in physical climate on forest soilacidification through internal proton production, in determiningsoil solution chemistry. A framework outlining the etiology offorest die-back induced by nitrogen saturation is proposed.
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    URL: http://dx.doi.org/10.1023/A:1005814929879
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    Temperature effect on shear induced transition in surfactant solution (1997)
    Springer
    Colloid & polymer science 105 (1997), S. 322-325 
    Details
    ISSN: 1435-1536
    Keywords: Rheology ; surfactant solutions ; micelles ; phase transition ; temperature
    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 Aqueous solutions of cationic surfactant with binding counterions exhibit a transition under shear. In this paper the steady shear properties of semidilute aqueous micellar solutions (cetylpyridinium chloride and sodium salicylate in brine) are presented as a function of concentration and temperature. The shear thinning behavior of this system could be described by the Carreau model at low shear rate and by a power law at higher shear rate. The temperature dependence of the zero shear viscosity follows an Arrhenius relationship. The critical shear rate at which the viscosity departs from its zero shear value is found to increase with temperature indicating the influence of this parameter on transition.
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    Low ambient temperature decreases cadmium accumulation in the liver and kidneys of the bank vole (Clethrionomys glareolus) (1996)
    Springer
    BioMetals 9 (1996), S. 363-369 
    Details
    ISSN: 1572-8773
    Keywords: cadmium ; copper ; iron ; photoperiod ; temperature ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The importance of photoperiod and ambient temperature on the accumulation of cadmium in the liver and kidneys of bank voles was determined in the present study. Males and females, aged 1 month, were given 3.0 μg Cd ml−1 drinking water and divided into four groups according to photoperiod (16 h light/8 h dark and 8 h light/16 h dark) and ambient temperature (20 or 5°C); liver and kidneys were removed for cadmium as well as copper, iron and zinc analyses at the end of 6 weeks. Bank voles exposed to 5°C in both photoperiods consumed approximately 30% less water containing cadmium than those kept at 20°C. However, the total accumulation of cadmium in the liver and kidneys of males and females exposed to the low temperatures was 4.3–4.8 and 2.2–3.3 times less than that in animals maintained at room temperature in the long and short photoperiod, respectively. Simultaneously, the low temperature brought about an increase in the copper concentrations in the liver (12–43%) and kidneys (47–78%), giving rise to an inverse correlation between the cadmium accumulation and the tissue copper concentration. In contrast to cadmium and copper, the concentrations of iron and zinc were affected primarily by photoperiod. These findings indicate that ambient temperature is an important determinant of cadmium retention in the bank vole. It appears that low temperature decreases tissue cadmium accumulation not only by reducing cadmium intake but also through changes in copper metabolism.
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    URL: http://dx.doi.org/10.1007/BF00140605
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    Ion association of dilute aqueous sodium hydroxide solutions to 600°C and 300 MPa by conductance measurements (1996)
    Springer
    Journal of solution chemistry 25 (1996), S. 711-729 
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    ISSN: 1572-8927
    Keywords: Conductivity ; aqueous ; sodium hydroxide ; ion association ; temperature ; pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The limiting molar conductances Λ0 and ion association constants of dilute aqueous NaOH solutions (〈0.01 mol-kg−1) were determined by electrical conductance measurements at temperatures from 100 to 600°C and pressures up to 300 MPa. The limiting molar conductances of NaOH(aq) were found to increase with increasing temperature up to 300°C and with decreasing water density ρw. At temperatures ≥400°C, and densities between 0.6 to 0.8 g-cm−3, Λ0 is nearly temperature-independent but increases linearly with decreasing density, and then decreases at densities 〈0.6 g-cm−3. This phenomenon is largely due to the breakdown of the hydrogen-bonded, structure of water. The molal association constants K Am for NaOH( aq ) increase with increasing temperature and decreasing density. The logarithm of the molal association constant can be represented as a function of temperature (Kelvin) and the logarithm of the density of water by $$\begin{gathered} log K_{Am} = 2.477 - 951.53/T - (9.307 \hfill \\ - 3482.8/T)log \rho _{w } (25 - 600^\circ C) \hfill \\ \end{gathered} $$ which includes selected data taken from the literature, or by $$\begin{gathered} log K_{Am} = 1.648 - 370.31/T - (13.215 \hfill \\ - 6300.5/T)log \rho _{w } (400 - 600^\circ C) \hfill \\ \end{gathered} $$ which is based solely on results from the present study over this temperature range (and to 300 MPa) where the measurements are most precise.
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    Modeling the temperature response of nitrification (1996)
    Springer
    Biogeochemistry 35 (1996), S. 433-445 
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    ISSN: 1573-515X
    Keywords: ammonium oxidation ; growth rate ; maintenance energy ; modeling ; nitrification ; soil nitrate ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract To model nitrification rates in soils, it is necessary to have equations that accurately describe the effect of environmental variables on nitrification rates. A variety of equations have been used previously to describe the effect of temperature on rates of microbial processes. It is not clear which of these best describes the influence of temperature on nitrification rates in soil. I compared five equations for describing the effects of temperature on nitrification in two soils with very different temperature optima from a California oak woodland-annual grassland. The most appropriate equation depended on the range of temperatures being evaluated. A generalized Poisson density function best described temperature effects on nitrification rates in both soils over the range of 5 to 50 °C; however, the Arrhenius equation best described temperature effects over the narrower range of soil temperatures that normally occurs in the ecosystem (5 to 28 °C). Temperature optima for nitrification in most of the soils were greater than even the highest soil temperatures recorded at the sites. A model accounting for increased maintenance energy requirements at higher temperatures demonstrates how net energy production, rather than the gross energy production from nitrification, is maximized during adaptation by nitrifier populations to soil temperatures.
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    Excess volumes of binary mixtures of ethylbenzene with octanol, nonanol and dodecanol from 50 to 100°C and 0.1 to 7.5 MPa (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 153-170 
    Details
    ISSN: 1572-8927
    Keywords: Densities ; excess volume ; pressure ; temperature ; ethylbenzene ; octanol ; nonanol ; dodecanol ; order creation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The excess volume V E of binary mixtures of octanol, nonanol and dodecanol in ethylbenzene have been calculated from the densities measured with a vibrating tube densimeter at temperatures from 50 to 100 °C and at pressures from 0.1 to 7.5 MPa. The values of V E are positive for all the three mixtures in the complete temperature, pressure and mole fraction ranges studied. The maxima in V E is observed at 0.4 mole fraction of alkanol. The results are discussed in terms of specific interactions present in the binary mixtures. The second order thermodynamic quantities (∂V E /∂T)p,(∂V E /∂P)T and (∂V E /∂P)T which have been derived from the effect of temperature and pressure on V E , indicate an overall net creation of order in the binary mixtures of ethylbenzene with higher homologues of alkanols.
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    URL: http://dx.doi.org/10.1007/BF00972839
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    Electrical conductances of aqueous sodium trifluoromethanesulfonate from 0 to 450°C and pressures to 250 MPa (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 753-769 
    Details
    ISSN: 1572-8927
    Keywords: Conductivity ; sodium trifluoromethanesulfonate ; ion association ; temperature ; pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrical conductances of dilute (0.001 to 0.1 mol-kg−1) aqueous sodium trifluoromethanesulfonate (NaCF3SO3) solutions have been measured from 0 to 450°C and pressures to 250 MPa. The limiting molar conductance $$\Lambda _0 $$ increases with increasing temperature from 0 to 300°C and decreasing density from 0.8 to 0.3 g-cm−3. Above 300°C, $$\Lambda _0 $$ is nearly temperature independent, but increases linearly with decreasing density. The logarithm of the molal association constant of NaCF3SO3 calculated at temperatures from 372 to 450°C is represented as a function of temperature (Kelvin) and density of water (g-cm−3) by $$\log K_m = 0.888 - 330.4/T - (12.83 - 5349/T)\log \rho _w $$ The relative strengths of NaCF3SO3 and NaCl are similar within the accuracy of the current measurements over the limited range of temperature and pressure that could be investigated here.
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    Characterization of a twin-torch transferred dc arc (1995)
    Springer
    Plasma chemistry and plasma processing 15 (1995), S. 309-331 
    Details
    ISSN: 1572-8986
    Keywords: Transferred arc ; voltage-current characteristic ; inhomogeneous plasma ; optical emission spectroscopy ; electron density ; temperature ; spatial distribution
    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 results of a twin-torch transferred de arc .study are presented. The arc system consists of two torches of opposite polarity, and a coupling zone of plasma jets located between them. The torch configuration increases the system reliability and efficiency during material plasma processing. The results of the study present data for the voltage-current characteristics, general behavior of the twin-torch arc, and spatial distribution of the plasma parameters. The plasma parameters have been measured using optical emission spectroscopy for a 200 A (20 k W) do arc, at atmospheric pressure, with argon and nitrogen introduced as plasma forming gases into the anode and the cathode units, respectively. The measurement technique used has allowed the determination of local electron density and temperature values in an inhomogeneous plasma volume having no axial sysmmetry. The data obtained illustrate the novel features of the twin-torch transfrred do arc for its applications in plasma processing.
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    Hydrogen/argon plasma jet with methane addition (1995)
    Springer
    Plasma chemistry and plasma processing 15 (1995), S. 333-351 
    Details
    ISSN: 1572-8986
    Keywords: Hydrogen/argon plasma ; methane ; do arc jet ; atmospheric pressure ; optical emission spectroscopy ; temperature ; density ; spatial distribution
    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 Spatial distributions of plasma parameters are presented for a H2/Ar plasma jet with addition of methane. The plasma has been generated at atmospheric pressure by a 200 A (20 kW) nontransferred do arc. Optical emission spectroscopy has been used for the measurements assuming the plasma jet to be optically thin and to have an axial symmetry. Local spectral ernissivity values have been evaluated using a routine Abel inversion procedure. Half- width and emissivity of Hβ spectral line have been measured to determine the electron density and temperature of the plasma. The densities of excited C, CH radicals have been evaluated from the absolute emissivities of relevant molecular emission bands measured in limited spectral intervals in the visible spectrum. The emissivity ratios have been used to fund rotational and vibrational temperatures. The results supply information on methane decomposition and the behavior of molecular radicals in close-to-thermal plasma jets.
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    URL: http://dx.doi.org/10.1007/BF01459702
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    PGSE-NMR studies of solvent diffusion in poly(N-isopropylacrylamide) colloidal microgels (1995)
    Springer
    Colloid & polymer science 273 (1995), S. 405-411 
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    ISSN: 1435-1536
    Keywords: NMR diffusion ; solvent diffusion ; hydrogels ; microgels ; temperature
    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 solvent self-diffusion coefficient has been studied in thermoshrinking poly(N-isopropyl acrylamide) microgel dispersions by the pulsed-gradient spin-echo PGSE-NMR technique, as a function of temperature and mass fraction. After suitable corrections for the temperature, the H2O/D2O ratio and the relative volume fractions, all the self-diffusion data obtained over a temperature range of approximately 40 °C and mass fraction (2–12 % wt/wt) could be superimposed with the volume fraction as the universal factor. The observed reduction in the solvent self-diffusion coefficient with volume fraction was greater than that predicted by simple obstruction theory. After correction for-, and the subsequent removal of the obstruction effect, the diffusion of the solvent through the core of the particle is elucidated. As found for other polymer-solvent systems, there were no specific binding effects. The diffusion of the solvent in these dispersions over such temperature and mass fraction ranges could be rationalised assuming a constant solvent self-diffusion coefficient in the core of the particles.
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    Electrical conductivity measurements of aqueous sodium chloride solutions to 600°C and 300 MPa (1994)
    Springer
    Journal of solution chemistry 23 (1994), S. 997-1018 
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    ISSN: 1572-8927
    Keywords: Conductivity ; aqueous ; sodium chloride ; pressure ; ion association ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electrical conductance measurements of dilute (〈0.1 mol-kg−1) aqueous NaCl solutions were made primarily to quantify the degree of ion association which increases with increasing temperature and decreasing solvent density. These measurements were carried out at temperatures from 100 to 600°C and pressures up to 300 MPa with a modified version of the apparatus used previously in the high temperature study in this laboratory. Particular emphasis was placed on conditions close to the critical temperaturelpressure region of water, i.e., at 5° intervals from 370 to 400°C. The results verify previous findings that the limiting equivalent conductance Ao of NaCl increases linearly with decreasing density from 0.75 to 0.3 g-cm−1 and also with increasing temperature from 100 to 350°C. Above 350°C. Ao is virtually temperature independent. The logarithm of the molal association constant as calculated exclusively from the data≥400°C is represented as a function of temperature (Kelvin) and the logarithm of the density of water (g-cm−3) as follows: $$log K_m = 0.997 - 650.07/T - (10.420 - 2600.5/T)log\rho _w $$ Note that this function also provides a good representation of the log Km values obtained from 350 to 395°C at densities greater than ca. 0.6 g-cm−3. More precise conductance data now available in the literature suggest a systematic error of unknown origin may exist in the data obtained at lower densities in this region. The relevant thermodynamics quantities derived from differentiation of this equation with respect to temperature and pressure are listed in the text.
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    The effect of temperature and pressure on the protonation ofo-phosphate ions at 348.15 and 398.15 K, and at 1.52 and 12.50 MPa (1994)
    Springer
    Journal of solution chemistry 23 (1994), S. 449-468 
    Details
    ISSN: 1572-8927
    Keywords: Phosphate ; protonation ; temperature ; pressure ; calorimetry ; equilibrium constants ; enthalpy and entropy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Flow calorimetry has been used to study the interaction of HPO 4 2− and H2PO 4 − with H+ in water at temperatures of 348.15 and 398.15 K and at pressures of 1.52 and 12.50 MPa. The protonations of HPO 4 2− and H2PO 4 − are exothermic and endothermic, respectively, under these experimental conditions. Under the conditions of this study, the effect of pressure on the enthalpy changes for both reactions is small. Equilibrium constant K, enthalpy change ΔH, and entropy change ΔS values are given for the protonation reactions at each temperature. These values are compared with those reported in the literature. Incorporation into the calculation procedure of reactions involving association between protonated phosphate species to form hydrogen-bonded dimers does not result in better fits of the experimental data.
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    Temperature and flow-induced viscosity transitions for CTAB surfactant solutions (1994)
    Springer
    Rheologica acta 33 (1994), S. 431-437 
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    ISSN: 1435-1528
    Keywords: Cetyltrimethylammonium bromide (CTAB) ; temperature ; shear-induced structure ; non-Newtonian viscosity ; micelles ; phase transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract We report in this work new results concerning the temperature dependence of the non-Newtonian viscosity of semi-diluted aqueous micellar solutions of cetyltrimethylammonium bromide (CTAB) in the presence of potassium bromide (KBr). Two structural transitions are responsible for the unusual flow curves obtained. The first transition induced by the shear flow corresponds to an induced liquid crystalline phase of the nematic type; the second corresponds to the disappearing of this phase with increase of the temperature.
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    Air microwave-induced plasma: Detection of NO in the post-discharge using an ArF laser (1993)
    Springer
    Plasma chemistry and plasma processing 13 (1993), S. 351-364 
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    ISSN: 1572-8986
    Keywords: Air microwave plasma ; laser-induced fluorescence ; temperature ; nitrogen monoxide density
    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 ArF laser-induced fluorescence (LIF) spectroscopy was applied to the investigation of the density of NO achieved in the post-discharge of an N2-O2 microwave-induced plasma (2450 MHz). The fluorescence spectrum provides a determination of NO vibrational temperature downstream the discharge. Absolute concentration profiles were determined in the low-temperature region of the post-discharge.
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    Outwardly rectifying chloride channels in lymphocytes (1992)
    Springer
    The journal of membrane biology 127 (1992), S. 49-56 
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    ISSN: 1432-1424
    Keywords: chloride channel ; lymphocyte ; outward rectification ; temperature ; regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Outwardly rectifying Cl− channels in cultured human Jurkat T-lymphocytes were activated by excising a patch of membrane using the inside-out (i/o) patch-clamp configuration and holding at depolarized voltages for prolonged periods of time (1–6 min at +80 mV, 20°C). The single-channel current at +80 mV was 4.5 ± 0.3 pA and at −80 mV, it was 1.0 ± 0.4 pA. After activation, the probability of being open (P 0)for the lymphocyte channel was voltage independent. Activation of the Cl− channel in lymphocytes was temperature dependent. Nineteen percent of i/o recordings from lymphocytes made at 20°C exhibited Cl− channel activity. In contrast, 49% of recordings made at 30°C showed channel activity. The number of channels in an active patch was not significantly different at the two temperatures. Channel activation in excised, depolarized patches also occurred 20-fold faster at 30°C than at 20°C. There was no marked change in the single-channel conductance at 30°C. Open-channel conductance was blocked by 200 μm indanyloxyacetic acid (IAA) or 1 mm SITS when applied to the intracellular side of the patch. The characteristics of this channel are similar to epithelial outwardly rectifying Cl− channels thought to be involved in fluid secretion
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    Cl− channels in intact human T lymphocytes (1992)
    Springer
    The journal of membrane biology 125 (1992), S. 171 
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    ISSN: 1432-1424
    Keywords: chloride channel ; cell-attached patches ; lymphocyte ; T cell ; temperature ; voltage dependence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary We recently described a large, multiple-conductance Cl− channel in excised patches from normal T lymphocytes. The properties of this channel in excised patches are similar to maxiCl− channels found in a number of cell types. The voltage dependence in excised patches permitted opening only at nonphysiological voltages, and channel activity was rarely seen in cell-attached patches. In the present study, we show that Cl− channels can be activated in intact cells at physiological temperatures and voltages and that channel properties change after patch excision. Maxi-Cl− channels were reversibly activated in 69% of cellattached patches when the temperature was above 32°C, whereas fewer than 2% of patches showed activity at room temperature. Upon excision, the same patches displayed large, multiple-conductance Cl− channels with characteristics like those we previously reported for excised patches. After patch excision, warm temperatures were not essential to allow channel activity; 37% (114/308) of inside-out patches had active channels at room temperature. The voltage dependence of the channels was markedly different in cell-attached recordings compared with excised patches. In cell-attached patches, Cl− channels could be open at cell resting potentials in the normal range. Channel activation was not related to changes in intracellular Ca2+ since neither ionomycin nor mitogens activated the channels in cell-attached patches, Ca2+ did not rise in response to warming and the Cl− channel was independent of Ca2+ in inside-out patches. Singlechannel currents were blocked by internal or external Zn2+ (100–200 μm), 4-acetamido-4′ isothiocyanostilbene-2,2′-disulfonate (SITS, 100–500 μm) and 4,4′-diisothiocyanostilbene 2,2′disulfonate (DIDS, 100 μm). NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate) reversibly blocked the channels in inside-out patches.
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    URL: http://dx.doi.org/10.1007/BF00233356
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    Soil surface CO2 flux in a Minnesota peatland (1992)
    Springer
    Biogeochemistry 18 (1992), S. 37-51 
    Details
    ISSN: 1573-515X
    Keywords: carbon dioxide ; microhabitat ; peat ; temperature ; water table
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Soil surface CO2 flux was measured in hollow and hummock microhabitats in a peatland in north central Minnesota from June to October in 1991. We used a closed infrared gas exchange system to measure soil CO2 flux. The rates of CO2 evolution from hummocks (9.8 ± 3.5 g m−2 d−1, [mean ± SE]) were consistently higher than those from hollows (5.4 ± 2.9 g m−2 d−1) (the hummock values included the contribution of moss dark respiration, which may account for 10–20% of the total measured flux). The soil CO2 flux was strongly temperature-dependent (Q10 ≈ 3.7) and appeared to be linearly related to changes in water table depth. An empirical multiplicative model, using peat temperature and water table depth as independent variables, explained about 81% of the variance in the CO2 flux data. Using the empirical model with measurements of peat temperature and estimates of hollow/hummock microtopographic distribution (relative to water table elevation), daily rates of “site-averaged” CO2 evolution were calculated. For the six-month period (May–October), the total soil CO2 released from this ecosystem was estimated to be about 1340 g CO2 m−2.
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    URL: http://dx.doi.org/10.1007/BF00000425
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    Temperature dependence of the non-Newtonian viscosity of elongated micellar solutions (1992)
    Springer
    Colloid & polymer science 270 (1992), S. 1035-1041 
    Details
    ISSN: 1435-1536
    Keywords: Elongated micelles ; cetyltrimethylammonium bromide (CTAB) ; non-Newtonianviscosity ; shearrate ; concentration ; temperature
    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 We report in this work new results of the study on the non-Newtonian viscosity of aqueous micellar solutions of cetyltrimethylammonium bromide (CTAB) in the presence of potassium bromide (KBr), in the concentration range where the elongated micelles overlap. The experiments have been performed as a function of the surfactant concentration, temperature and shear rate by use of a Couette-viscosimeter. In the non-Newtonian range, at relatively low surfactant concentration (≲0.25 M/l), our results show that the flow curves obtained at different temperatures converge to a single liner curve with a characteristic slope varying with the surfactant concentration. These same data can be superposed on a master curve when appropriate reduced variables are used. The shape of the flow curves obtained at different temperatures for a sufficiently high surfactant concentration is similar to that obtained for monodisperse polymer solutions at different molecular weights. The slope obtained of about −1 is also predicted by Graessley's model in the theory of microviscoelasticity based on the concept of entanglement for polymer solutions. However, at surfactant concentration higher than 0.25 M/l our results show an unusual behavior. Above some critical shear rate it is possible to obtain an increase of the apparent viscosity with temperature. One possible explanation of this effect can be found in the increase of the entanglement with concentration coupled with the temperature and direct now effects on scission and recombination rate of the micelles.
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    An Electrically Modulated Drug Delivery Device. II. Effect of Ionic Strength, Drug Concentration, and Temperature (1992)
    Springer
    Pharmaceutical research 9 (1992), S. 215-219 
    Details
    ISSN: 1573-904X
    Keywords: electrophoresis ; electrically modulated drug delivery device ; chronotherapeutics ; ionic strength ; drug concentration ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The effects of various physicochemical parameters on the changes in drug delivery rate produced by an electrophoretic current are examined using a model system. It was shown that ionic strength has an inverse relationship with the change in delivery rate produced by a given current. Small changes in pH were measured during electrophoresis experiments which were considered to be insignificant. Drug reservoir concentration selection is critical in the design of an electrophoretic device and is based on achieving a balance between providing a suitable reservoir and allowing adequate electrophoretic control. Electrophoretic control is affected by temperature in a manner which can be predicted using the Arrhenius relationship. The low power requirements of the model system demonstrate the feasibility of using the principle of electrophoresis to control drug delivery rates in a therapeutic system.
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    URL: http://dx.doi.org/10.1023/A:1018937407071
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    Thermodynamic properties for binary liquid mixtures of 1-chlorobutane+n-alkanes (1991)
    Springer
    Journal of solution chemistry 20 (1991), S. 805-816 
    Details
    ISSN: 1572-8927
    Keywords: Alkanes ; 1-chlorobutane ; compressibilities ; excess volume ; expansibilities ; heat capacities ; heat of mixing ; liquids ; pressure ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Isothermal compressibilities KΥ and isobaric thermal expansion coefficients αp have been measured at 25 and 45°C for pure components and the following binary mixtures: 1-chlorobutane+normal alkanes (n-Cn) where n=6, 8, 10, 12, 14 and 16. With these results and other thermodynamic data from literature the next mixing quantities have also been reported: (∂V E/∂T)P, − (∂V)E/∂P)T, K S v , ∂H E/∂P)T, Δ(αpγVT and ΔCv. The obtained results have been compared at 25°C with the calculated values by using the Prigogine-Flory-Patterson theory of liquid mixtures. The theory predicts the excess volume VE and ∂V E/∂P)T values rather well, the C P E quite poorly, while for ∂V E/∂T)P and ∂V E/∂P)T it is only predicted the trend with the chain length of the n-alkane. The last two quantities show deviations between theoretical and experimental, slightly higher in systems with longer n-alkanes than for shorter ones. Our conclusion is that a nonrigid linear molecule, like 1-chlorobutane, has a low ability as a breaker of the pure n-Cn orientation correlations, in between that which we found for toluene and p-xylene and much smaller than for cyclohexane or benzene.
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    In situ high temperature and high pressure exafs studies of Pt/Al2O3 Catalysts. Part II: Carbon removal (1991)
    Springer
    Catalysis letters 8 (1991), S. 297-304 
    Details
    ISSN: 1572-879X
    Keywords: EXAFS ; Pt/Al2O3 catalyst ; temperature ; pressure ; carbon deposition ; carbon removal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract EXAFS has been used to follow in situ the structural evolution of a Pt/Al2O3 catalyst during removal of carbon by hydrogenation, after reduction and carbon deposition. After reduction at 350 °C, the total hydrogen pressure was raised to 3 atm. and n-heptane was injected over the sample. EXAFS measurements at the Pt edge were carried out with simultaneous on-line EXAFS analysis of the spectra. After observing the rapid formation of a carbon-platinum bond which is unmodified with time, we stopped the heptane flow, raised the temperature to 450 °C, and maintained hydrogen flow at 3 atm. The disappearance of the platinum-carbon bond during heat treatment in hydrogen was monitored via on-line analysis. No sintering of the metal particles was observed. EXAFS is thus proven to be an efficient tool to study not just structural changes of a catalyst during a hydrocarbon reaction [1], but also to use it as a technique to study other catalytic phenomena as well.
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    In situ high temperature and high pressure exafs studie of Pt/Al2O3 catalysts. Part I: Reduction and deactivation (1991)
    Springer
    Catalysis letters 8 (1991), S. 283-295 
    Details
    ISSN: 1572-879X
    Keywords: EXAFS ; Pt/Al2O3 catalysts ; chlorine ; temperature ; pressure ; reduction ; deactivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract EXAFS has been used to follow in situ the structural evolution of a chlorinated and non-chlorinated Pt/Al2O3 catalyst during reduction in the temperature range of 300–500 °C. Smaller metal clusters are formed from the hydrogen reduction of the chlorinated catalyst, in contrast to the larger cluster formed from the non-chlorinated one. At 460 °C, the total hydrogen pressure was raised to 5 atm. and n-heptane was injected over the samples. EXAFS measurements at the Pt edge were carried out while hydrocarbon conversion was monitored with a gas Chromatograph. We observe the rapid formation of a carbon-platinum bond. This is unmodified while turnover rates and selectivities indicate evidence for deactivation. From this structural information supplied by EXAFS, correlated with the data obtained from gas chromatography, we find that our results are consistent with a model proposed by others where deactivation is due to the build-up of a multilayer of carbon.
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    Response of chloride efflux from skeletal muscle ofRana pipiens to changes of temperature and membrane potential and diethylpyrocarbonate treatment (1991)
    Springer
    The journal of membrane biology 123 (1991), S. 223-233 
    Details
    ISSN: 1432-1424
    Keywords: skeletal muscle ; Cl− efflux ; Cl− channel ; pH ; muscle membrane ; temperature ; diethylpyrocarbonate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Efflux of36Cl− from frog sartorius muscles equilibrated in two depolarizing solutions was measured. Cl− efflux consists of a component present at low pH and a pH-dependent component which increases as external pH increases. For temperatures between 0 and 20°C, the measured activation energy is 7.5 kcal/mol for Cl− efflux at pH 5 and 12.6 kcal/mol for the pH-dependent Cl− efflux. The pH-dependent Cl− efflux can be described by the relationu=1/(1+10n(pK a -pH)), whereu is the Cl− efflux increment obtained on stepping from pH 5 to the test pH, normalized with respect to the increment obtained on stepping from pH 5 to 8.5 or 9.0. For muscles equilibrated in solutions containing 150mm KCl plus 120mm NaCl (internal potential about −15 mV), the apparent pK a is 6.5 at both 0 and 20°C, andn=2.5 for 0°C and 1.5 for 20°C. For muscles equilibrated in solutions containing 7.5mm KCl plus 120mm NaCl (internal potential about −65 mV), the apparent pK a at 0°C is 6.9 andn is 1.5. The voltage dependence of the apparent pK a suggests that the critical pH-sensitive moiety producing the pH-dependent Cl− efflux is sensitive to the membrane electric field, while the insensitivity to temperature suggests that the apparent heat of ionization of this moiety is zero. The fact thatn is greater than 1 suggests that cooperativity between pH-sensitive moieties is involved in determining the Cl− efflux increment on raising external pH. The histidine-modifying reagent diethylpyrocarbonate (DEPC) applied at pH 6 reduces the pH-dependent Cl− efflux according to the relation, efflux=exp(−k·[DEPC]·t), wheret is the exposure time (min) to DEPC at a prepared initial concentration of [DEPC] (mm). At 17°C,k −1=188mm·min. For temperatures between 10 and 23°C,k has an apparent Q10 of 2.5. The Cl− efflux inhibitor SCN− at a concentration of 20mm substantially retards the reduction of the pH-dependent Cl− efflux by DEPC. The findings that the apparent pK a is 6.5 in depolarized muscles, that DEPC eliminates the pH-dependent Cl− efflux, and that this action is retarded by SCN− supports the notion that protonation of histidine groups associated with Cl− channels is the controlling reaction for the pH-dependent Cl− efflux.
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    Extremely low temperatures in the stratosphore and very low total ozone amount above northern and central Europe during winter 1989 (1991)
    Springer
    Journal of atmospheric chemistry 12 (1991), S. 381-390 
    Details
    ISSN: 1573-0662
    Keywords: Ozone ; total ozone ; temperature ; stratosphere ; stratospheric warming ; Antarctic ozone hole ; polar stratospheric clouds ; ozone depletion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract On 1 February 1989, -83.5°C was recorded in 27.8 hPa over Hohenpeißenberg, the lowest temperature in the 22-year series. This was measured together with a very low total ozone amount of 266 DU. This may be compared with nearly twice this amount on 27 February 1989. The situation was very unusual: following an extremely cold winter in the Arctic stratosphere, the stratospheric cold pole was located over southern Scandinavia on 1 February in a very southerly position. The analyzed temperatures of -92 °C in 30 hPa were also unusual. Even though the low ozone amounts over Hohenpeißenberg were probably dynamically caused, an additional very small ozone decrease due to heterogeneous reactions in altitudes from 23–28 km, where the temperatures lie below -80 °C, cannot be ruled out. Extinction measurements by the orbitting SAGE II instrument indeed show polar stratospheric clouds over Europe near 50° N during the period 31 January–2 February. Also, polar stratospheric clouds were previously observed over Kiruna at similarly low temperatures and signs of a corresponding small ozone decrease were noted there.
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    Studies in Phlebitis. II. Early Detection of Amiodarone-Induced Phlebitis in a Rabbit Model (1991)
    Springer
    Pharmaceutical research 8 (1991), S. 801-803 
    Details
    ISSN: 1573-904X
    Keywords: phlebitis ; thrombophlebitis ; temperature ; detection ; thermocouple ; amiodarone ; prevention ; parenteral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1023/A:1015874722653
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    First and second thermodynamic mixing properties of ethylbenzene +n-alkanes: Experimental and theory (1990)
    Springer
    Journal of solution chemistry 19 (1990), S. 1137-1151 
    Details
    ISSN: 1572-8927
    Keywords: Ethylbenzene ; excess entalphy ; excess volume ; experimental ; heat capacity ; isobaric expansibility ; isentropic and isothermal compressibility ; liquid mixtures ; mixing function ; n-alkanes ; n-hexadecane ; n-tetradecane ; pressure ; temperature ; theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Isobaric expansibilities α P and isothermal compressibilities κ T have been determined at 25 and 45°C for binary mixtures of ethylbenzene + n-tetradecane and + n-hexadecane and the corresponding excess functions (∂V E /∂T)P and (∂V E /∂P)T have also been obtained. With these data and supplementary literature values, the following second order mixing properties are also reported at 25°C: κ S E , (∂V E /∂P)T, ΔCV and Δ(ΔγVT). All mixing quantities have been compared with the results obtained at 25°C by using the Prigogine-Flory-Patterson theory of liquid mixtures. The predicted values suggest that the ability of ethylbenzene as a breaker of the pure n-Cn orientations is similar to what we found for toluene and higher than for p-xylene.
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    Release rates of tetradecen-1-ol acetates from polymeric formulations in relation to temperature and air velocity (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 1041-1058 
    Details
    ISSN: 1573-1561
    Keywords: Air velocity ; controlled release ; formulation ; pheromone ; release rate ; temperature ; tetradecen-1-ol acetates ; vapor collection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An apparatus was developed for investigating the release rates of pheromone formulations at temperatures and air velocities that correspond with those in the field. Polyurethane foam proved an excellent adsorbent for the recovery of tetradecen-1-ol acetates, allowing high air flows at low differential pressure and without breakthrough of these compounds. The experimental setup and procedures are described. The release rates of all formulations investigated were almost proportional to the square root of air velocity, and their logarithms were proportional to the reciprocal of temperature (K). When temperature is increased from 15°C to 25°C, the release rates increase by about 2-2.5 ×. Both relationships were combined into one equation that allows a reliable estimate to be made of the actual release rates of a formulation, under varying conditions, on the basis of its specific parameters and the relevant meteorological data.
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    Raman spectroscopic studies of hen egg-white lysozyme at high temperatures and pressures (1990)
    Springer
    The protein journal 9 (1990), S. 475-486 
    Details
    ISSN: 1573-4943
    Keywords: Lysozyme ; pressure ; temperature ; Raman
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In situ high-temperature, high-pressure Raman experiments on 3 mM (pH 5) aqueous solutions of hen egg-white (HEW) lysozyme show a decrease in the relative height of the 505 cm−1 band associated with S-S stretching vibrations at 72°C (1 bar). The peak height changes are accompanied by significant band broadening, and the integrated band intensity does not change within experimental error. The effect of increased pressure at 72°C was to hinder broadening of the 505 cm−1 band. HEW lysozyme (2.4 mM,pH 5) was also heated at 76°C, 80°C, and 95°C for different periods of time, and aliquots were quenched to room temperature for Raman and enzymatic activity measurements. After 9 hr at 76°C, the protein exhibits enzyme activity less than 50% of the initial value, and approximately 50% reduction in activity is achieved after 3 hr at 80°C or 1 hr at 95°C. The Raman results suggest that different irreversibly denatured conformations are attained during prolonged exposures at these different temperatures. It is apparent from these studies that the S-S stretch intensity is decreased irreversibly.
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    Rheological properties of skim milk gels at various temperatures; interrelation between the dynamic moduli and the relaxation modulus (1990)
    Springer
    Rheologica acta 29 (1990), S. 223-230 
    Details
    ISSN: 1435-1528
    Keywords: Milkgels ; rheology ; stressrelaxation ; dynamicmoduli ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract The rheological properties of rennet-induced skim milk gels were determined by two methods, i.e., via stress relaxation and dynamic tests. The stress relaxation modulusG c (t) was calculated from the dynamic moduliG′ andG″ by using a simple approximation formula and by means of a more complex procedure, via calculation of the relaxation spectrum. Either calculation method gave the same results forG c (t). The magnitude of the relaxation modulus obtained from the stress relaxation experiments was 10% to 20% lower than that calculated from the dynamic tests. Rennet-induced skim milk gels did not show an equilibrium modulus. An increase in temperature in the range from 20° to 35 °C resulted in lower moduli at a given time scale and faster relaxation. Dynamic measurements were also performed on acid-induced skim milk gels at various temperatures andG c (t) was calculated. The moduli of the acid-induced gels were higher than those of the rennet-induced gels and a kind of “permanent” network seemed to exist, also at higher temperatures.
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    Temperature dependence of gating current in myelinated nerve fibers (1989)
    Springer
    The journal of membrane biology 112 (1989), S. 277-289 
    Details
    ISSN: 1432-1424
    Keywords: myelinated nerve fiber ; gating current ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Asymmetrical displacement currents and Na currents of single myelinated nerve fibers ofXenopus laevis were studied in the temperature range from 5 to 24°C. The time constant of the on-response atE=4 mV,τ on, was strongly temperature dependent, whereas the amount of displaced charge atE=39 mV, Qon, was only slightly temperature dependent. The mean Q10 forτ on -1 was 2.54, the mean Q10 for Qon was 1.07. The time constant of charge immobilization,τ i , atE=4 mV varied significantly (α=0.001) with temperature. The mean Q10 forτ i -1 was 2.71±0.38. The time constants of immobilization of gating charge and of fast inactivation of Na permeability were similar in the temperature range from 6 to 22°C. The Qoff/Qon ratio forE=4 mV pulses of 0.5 msec duration decreased with increasing temperature. The temperature dependence of the time constant of the off-response could not be described by a single Q10 value, since the Q10 depended on the duration of the test pulse. Increasing temperature shifted Qon (E) curves to more negative potentials by 0.51 mVK −1, but shiftedP Na (E) curves andh ∞ (E) curves to more positive potentials by 0.43 and 0.57 mV K−1, respectively.h ∞ (E=−70 mV) increased monotonously with increasing temperature. The present data indicate that considerable entropy changes may occur when the Na channel molecule passes from closed through open to inactivated states.
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    The adaptation of biological membranes to temperature and pressure: Fish from the deep and cold (1989)
    Springer
    Journal of bioenergetics and biomembranes 21 (1989), S. 115-135 
    Details
    ISSN: 1573-6881
    Keywords: Membrane fluidity ; fish membranes ; homeoviscous adaptation ; temperature ; hydrostatic pressure ; acclimation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract The homoeostatic regulation of bilayer order is a property of functional importance. Arguably, it is best studied in those organisms which experience and must overcome disturbances in bilayer order which may be imposed by variations in temperature of hydrostatic pressure. This article reviews our recent work on the adaptations of order in brain membranes of those fish which acclimate to seasonal changes in temperature or which have evolved in extreme thermal or abyssal habitats. The effects of temperature and pressure upon hydrocarbon order and phase state are reviewed to indicate the magnitude of the disturbances experienced by animals in their environments over the seasonal or evolutionary timescale. Acclimation of fish to altered temperature leads to a partial correction of order, while comparison of fish from extreme cold environments with those from temperate or tropical waters reveals a more complete adaptation. Fish from the deep sea also display adaptations of bilayer order which largely overcome the ordering effects of pressure.
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    The Effect of Ultrasound on the in Vitro Penetration of Ibuprofen Through Human Epidermis (1989)
    Springer
    Pharmaceutical research 6 (1989), S. 697-701 
    Details
    ISSN: 1573-904X
    Keywords: ultrasound ; phonophoresis ; temperature ; ibuprofen ; human skin ; in vitro percutaneous absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The objective of this study was to develop an in vitro method to investigate the effect of ultrasound on the in vitro absorption of ibuprofen from a propylene glycol/water vehicle through human epidermis. A diffusion cell was modified so ultrasound could be applied to the vehicle and skin. Since ultrasound can increase the temperature underneath the area of application, control representing temperature effects ran concurrently to the ultrasound experiment. The results demonstrate that ultrasound can increase the penetration of ibuprofen through human skin. This increase in diffusion was greater than for controls where an equivalent increase in temperature was utilized. The results also indicate that evaporation of vehicle components may alter the skin/vehicle partition coefficient, decreasing the effects of ultrasound on the penetration of ibuprofen through the skin.
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    Involvement of photosynthesis in the action of temperature on plasmalemma transport inNitella (1988)
    Springer
    The journal of membrane biology 103 (1988), S. 149-158 
    Details
    ISSN: 1432-1424
    Keywords: H+ pump ; K+ channel ; light ; Nitella ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary At membrane potentials different fromE K, the temperature effect on membrane potential ofNitella consists of two components. One of them changes its sign atE K, the other one does not. This leads to the assignment of these components to changes in the K+ channel and in the H+ pump, respectively. It is shown that the fast time constant (3 to 30 sec) of the temperature effect on the H+ pump measured as a change in membrane potential and that of the temperature effect on the K+ channel measured as a change in resistance (having about twice the value of that of the pump) are sensitive to light intensity. Both time constants measured inNitella become smaller if light intensity increases from 0 to 15 Wm−2. This supports the suggestion of Fisahn and Hansen (J. Exp. Bot. 37:440–460, 1986) that temperature acts on plasmalemma transport via photosynthesis via the same mechanism as light does.
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    Thermal instability of red blood cell membrane bilayers: Temperature dependence of hemolysis (1988)
    Springer
    The journal of membrane biology 101 (1988), S. 67-72 
    Details
    ISSN: 1432-1424
    Keywords: hemolysis ; membrane ; erythrocyte ; pyrexia ; phospholipid ; phase transition ; unilamellar ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Rates of human red blood cell hemolysis were measured as a function of temperature. Three distinct temperature intervals for hemolysis were noted: a) At temperatures equal to or less than 37°C no hemolysis was observed for the duration of the incubation (30 hr). b) For temperatures exceeding 45°C hemolysis rates are rapid and are accompanied by gross changes in cellular morphology. The activation energy for hemolysis is 80 kcal/mole; this value is characteristic of protein denaturation and enzyme inactivation suggesting that these processes contribute to hemolysis at these high temperatures. c) Between 38 and 45°C the energy of activation is 29 kcal/mole, indicating that a fundamentally different process than protein inactivation is responsible for hemolysis at these relatively low temperatures. A mechanism based on the concept of the critical bilayer assembly temperature of cell membranes (N.L. Gershfeld,Biophys. J. 50:457–461, 1986) accounts for hemolysis at these relatively mild temperatures: The unilamellar state of the membrane is stable at 37°C, but is transformed to a multibilayer when the temperature is raised; hemolysis results because formation of the multibilayer requires exposing lipid-free areas of the erythrocyte surface. An analysis of the activation energy for hemolysis is presented that is consistent with the proposed unilamellar-multibilayer transformation.
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    URL: http://dx.doi.org/10.1007/BF01872821
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    The modification of the triple helical structure of gelatin in aqueous solution I. The influence of anionic surfactants, pH-value, and temperature (1988)
    Springer
    Colloid & polymer science 266 (1988), S. 1061-1067 
    Details
    ISSN: 1435-1536
    Keywords: Circular dichroism ; gelatin ; sodium alkyl sulphates ; aqueousgelatinsolutions ; secondary structure ; pH ; temperature
    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 modification of the triple helical structure in aqueous gelatin solutions by changing pH and adding alkyl sulphates at 298 K and after rechilling the solution to 283 K was investigated by CD-measurement. At 298 K the triple helical content at the IEP of the gelatin has its maximum value. It is only weakly affected by adding sodium dodecyl sulphate (SDDS) at concentrations 〈10−4 M/dm3. The unfolding of the triple helix affected by pH and SDDS is reversible by rechilling the solution. The triple helical content of gelatin solutions decreases at SDDS concentrations higher than 10−4 M/dm3. In all cases the decrease of the amount of triple helical structure is connected with an increase of the cis-configuration in single chains and leads to chain reversals. At sufficiently high SDDS concentrationsβ-sheets are formed. These changes are thermally irreversible. Sodium decyl sulphate (SDS) has a more minor influence than SDDS except in the range of the c.m.c. of SDS. At sufficiently high SDS concentrations,β-turns appear.
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    URL: http://dx.doi.org/10.1007/BF01428818
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    Macromolecular interaction and the electrophoretic mobility of esterase-5 from Drosophila pseudoobscura (1987)
    Springer
    Biochemical genetics 25 (1987), S. 287-307 
    Details
    ISSN: 1573-4927
    Keywords: macromolecular interactions ; temperature ; electrophoresis ; esterase-5 ; Drosophila pseudoobscura
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Esterase-5 is one of the most polymorphic loci in Drosophila pseudoobscura. Some variants reportedly produce a dimeric enzyme, while a few produce a monomeric form. This paper reports the finding that during electrophoresis ESTERASE-5 exists in a dynamic equilibrium between monomers and dimers, an equilibrium that is dependent on the running temperature of the gels. This is shown by a series of analytical electrophoresis experiments in which the apparent molecular weights of several variants are determined at four different temperatures. Increasing temperatures result in a linear decrease in the logarithm of apparent molecular weights. Macromolecular interactions thus are a significant determinant of EST-5 electrophoretic mobility.
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    URL: http://dx.doi.org/10.1007/BF00499322
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    Characterization and temperature regulation of soluble proteins of a male sterile tomato mutant (1987)
    Springer
    Biochemical genetics 25 (1987), S. 717-728 
    Details
    ISSN: 1573-4927
    Keywords: male sterility ; mutant ; proteins ; temperature ; tomato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The soluble proteins of the normal and male-sterile stamenless-2 (sl-2/sl-2) mutant of tomato(Lycopersicon esculentum) grown in different temperatures were analyzed by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The normal and mutant stamens had some common proteins, but certain proteins were either present or more enriched in one genotype than in the other. The other floral organs of the normal and mutant showed no major differences in proteins, suggesting that the sl-2/sl-2 allele is active primarily in anther development. Normal and mutant stamens grown in high temperatures were enriched in some proteins in comparison to the intermediate temperatures. At low temperatures, the protein pattern of normal and mutant stamens was essentially similar.
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    URL: http://dx.doi.org/10.1007/BF00556214
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    Effects of anisosmotic medium on cell volume, transmembrane potential and intracellular K+ activity in mouse hepatocytes (1987)
    Springer
    The journal of membrane biology 100 (1987), S. 53-61 
    Details
    ISSN: 1432-1424
    Keywords: hepatocyte ; cell volume ; K+ conductance ; temperature ; quinine HCl ; intracellular K+ activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Mouse hepatocytes in primary monolayer culture (4 hr) were exposed for 10 min at 37°C to anisosmotic medium of altered NaCl concentration. Hepatocytes maintained constant relative cell volume (experimental volume/control volume) as a function of external medium relative osmolality (control mOsm/experimental mOsm), ranging from 0.8 to 1.5. In contrast, the relative cell volume fit a predicted Boyle-Van't Hoff plot when the experiment was done at 4°C. Mouse liver slices were used for electrophysiologic studies, in which hepatocyte transmembrane potential (V m ) and intracellular K+ activity (a K i ) were recorded continuously by open-tip and liquid ion-exchanger ion-sensitive glass microelectrodes, respectively. Liver slices were superfused with control and then with anisosmotic medium of altered NaCl concentration.V m increased (hyperpolarized) with hypoosmotic medium and decreased (depolarized) with hyperosmotic medium, and ln [10(experimentalV m /controlV m )] was a linear function of relative osmolality (control mOsm/experimental mOsm) in the range 0.8–1.5. Thea K i did not change when medium osmolality was decreased 40–70 mOsm from control of 280 mOsm. Similar hypoosmotic stress in the presence of either 60mm K+ or 1mm quinine HCl or at 27°C resulted in no change inV m compared with a 20-mV increase inV m without the added agents or at 37°C. We conclude that mouse hepatocytes maintain their volume anda K i in response to anisosmotic medium; however,V m behaves as an osmometer under these conditions. Also, increases inV m by hypoosmotic stress were abolished by conditions or agents that inhibit K+ conductance.
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    URL: http://dx.doi.org/10.1007/BF02209140
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    Efficiency, Na+/K+ selectivity and temperature dependence of ion transport through lipid membranes by (221)C10-Cryptand, an ionizable mobile carrier (1987)
    Springer
    The journal of membrane biology 97 (1987), S. 79-95 
    Details
    ISSN: 1432-1424
    Keywords: cryptand ; Na+ selectivity ; temperature ; ionizable mobile carrier ; nonactin ; cation transport kinetics ; lipid membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The kinetics of Na+ and K+ transport across the membrane of large unilamellar vesicles (LUV) were determined at two pH's when transport was induced by (221)C10-cryptand (diaza-1,10-decyl-5-pentaoxa-4,7,13,16,21-bicyclo [8.8.5.] tricosane) at various temperatures, and by nonactin at 25°C and (222)C10-cryptand at 20 and 25°C. The rate of Na+ and K+ transport by (221)C10 saturated with the cation and carrier concentrations. Transport was noncooperative and exhibited selectivity for Na+ with respect to K+. The apparent affinity of (221)C10 for Na+ was higher and less pH-dependent than that for K+, and seven times higher than that of (222)C10 for K+ ions (20.5vs. 1.7 kcal·mole−). The efficiency of (221)C10 transport of Na+ was pH-and carrier concentration-dependent, and was similar to that of nonactin; its activation energy was similar to that for (222)C10 transport of K+ (35.5 and 29.7 kcal · mole−1, respectively). The reaction orders in cationn(S) and in carrierm(M), respectively, increased and decreased as the temperature rose, and were both independent of carrier or cation concentrations; in most cases they varied slightly with the pH.n(S) varied with the cation at pH 8.7 and with the carrier for Na+ transport only, whilem(M) always depended on the type of cation and carrier. Results are discussed in terms of the structural, physico-chemical and electrical characteristics of carriers and complexes.
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    URL: http://dx.doi.org/10.1007/BF01869415
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    I/V-Curve studies of the control of a K+ transporter inNitella by temperature (1987)
    Springer
    The journal of membrane biology 98 (1987), S. 1-13 
    Details
    ISSN: 1432-1424
    Keywords: control ; curve fitting ; I/V curves ; K+ transporter ; Nitella ; lazy state ; reaction-kinetic model ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary InNitella, current-voltage relationships were measured at different temperatures ranging from 5 to 25°C. Sets of theseI/V curves were subject to curve fitting on the basis of a cyclic reaction scheme (Class I model). Different hypotheses of the mode of action of temperature on theI/V curve were tested, including changes in reaction constants in the transport cycle and deactivation of transport molecules. It was found that models assuming an influence of temperature on pairs of rate constants of the transport cycle gave very bad fits. Good fits were obtained with models implying that temperature influences the number of active transporters. The lazy-state model (the exchange of an inactive state with a stateN 3 in the transport cycle is influenced by temperature) gave a slightly better fit than the assumption of an unspecific inactivation (independent of the state of the transport molecule). According to the lazy-state analysis, the inactive state is kinetically closer toN o , the state in which the transport molecule is open to the outside substrate than toN i , the state in which it is open to the inside substrate. The two inactivation models imply that temperature does not act directly on the properties of the plasmamembrane, but that temperature-sensitive metabolic processes in the cell send signals which control the activation and deactivation of the transporter.
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    URL: http://dx.doi.org/10.1007/BF01871041
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    Pitzer-Debye-Hückel limiting slopes for water from 0 to 350°C and from saturation to 1 kbar (1986)
    Springer
    Journal of solution chemistry 15 (1986), S. 749-764 
    Details
    ISSN: 1572-8927
    Keywords: Apparent molar enthalpy ; heat capacity ; volume ; compressibility ; expansitivity ; Debye-Hückel limiting law ; dielectric constant ; PVT properties ; pressure ; temperature ; thermodynamic properties ; water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Using internationally recognized critical evaluations for the dielectric constant of water by Uematsu and Franck and the thermodynamic surface of water by Haar, Gallagher, and Kell, the Bureau of Mines presents values for the Pitzer-Debye-Hückel limiting slopes for osmotic coefficients, apparent molal enthalpies, apparent molal heat capacities, apparent molal volumes, molal compressibilities, and apparent molal expansivities from 0 to 350°C and from saturation to 1 kbar.
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    The effect of temperature on biochemical and molecular properties ofDrosophila alcohol dehydrogenase (1986)
    Springer
    Biochemical genetics 24 (1986), S. 873-889 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; alcohol dehydrogenase ; temperature ; adaptation ; enzyme polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The gene products of the two major alleles of alcohol dehydrogenase (ADH-F and ADH-S) have been subjected to kinetic and biochemical analyses over a range of temperatures. Although temperature was found to have a significant effect on both kinetic and biochemical properties ofDrosophila ADH, no significant differential effect was observed between the major ADH allozymes. The results are discussed within the context of the selective maintenance ofAdh polymorphism in natural populations.
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    Temperature effects on cholinesterases from rat brain capillaries (1986)
    Springer
    Bioscience reports 6 (1986), S. 573-577 
    Details
    ISSN: 1573-4935
    Keywords: temperature ; cholinesterases ; brain capillaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The activities of acetylcholinesterase (ACHE) and butyrylcholinesterase (BuChE) in rat brain capillaries were measured as a function of temperature. Arrhenius plots of the data revealed that AChE exhibits a biphasic Arrhenius plot with a distinct break (transition temperature) at about 15.2 kcal/mol. In contrast, BuChE did not show evidence of discontinuity. BuChE showed an activation energy higher than that of AChE in the physiological range of temperature. These data suggest a lack of lipid-protein interaction in the case of BuChE. Although the possibility exists that BuChE is weakly anchored to the membranes, our results indicate that BuChE is not bound, at least significantly, to cellular membranes in brain capillaries as is ACHE.
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    Dynamics of 6-methoxybenzoxazolinone in winter wheat (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 2011-2020 
    Details
    ISSN: 1573-1561
    Keywords: 6-Methoxybenzoxazolinone ; hydroxamic acids ; wheat ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 6-Methoxybenzoxazolinone (6-MBOA), a compound derivable from some freshly growing plants, is known to stimulate reproduction in some mammals and birds. Winter wheat was studied under controlled laboratory conditions to determine the effects of photoperiod and temperature on derivable 6-MBOA content. Longer photoperiods decrease the amount of derivable 6-MBOA per gram of fresh material in 4-day-old wheat seedlings. Higher temperatures also decrease the amount of derivable 6-MBOA in 4-day-old wheat. 6-MBOA content decreases as the plant ages. Comparisons of only the first centimeter above the seed produced the same age-related result. 6-MBOA is concentrated in the meristematic region with decreasing amounts found in higher portions of the plant. Roots from 9-day-old plants contain 6-MBOA. Unsprouted wheat seeds contain negligible amounts of 6-MBOA. These results demonstrate that environmental variables have a significant effect on derivable 6-MBOA levels, but that under all the regimes studied, 6-MBOA is present in freshly sprouted wheat.
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    Kinetic studies on void formation during liquid epoxy resin impregnation through polyester non-woven fabric (1985)
    Springer
    Colloid & polymer science 263 (1985), S. 454-461 
    Details
    ISSN: 1435-1536
    Keywords: Impregnation ; void ; liquid ; fabric ; temperature
    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 Under the condition that liquid epoxy resin impregnation was through polyester non-woven fabric sheets, sandwiched between two circular glass plates, the increase in gas pressure caused by decrease in the volume of non-impregnating area was not as much as expected according to Boyle's law. Hence, the quantity of the gas consumed by dissolution and diffusion into the liquid resin and the polyester fibers, as well as by the void formation in the impregnating area of liquid resin, was calculated. According to the results, the quantities of gas decreased by dissolution and diffusion from the non-impregnating area into the impregnating liquid resin and into the polyester fiber are found to be so small that the deviation from Boyle's law mostly depends on the gas consumption due to the void formation in the impregnating area. Observing the impregnating region with a microscope, many voids were found in the area between the non-impregnating area and the completely impregnated area. The number and size of voids are theoretically estimated by assuming the non-uniformity of the fiber distribution in the polyester non-woven fabric.
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    Temperature-related kinetic differentiation of glucosephosphate isomerase alleloenzymes isolated from the blue mussel,Mytilus edulis (1985)
    Springer
    Biochemical genetics 23 (1985), S. 705-728 
    Details
    ISSN: 1573-4927
    Keywords: glucosephosphate isomerase (EC 5.3.1.9) ; Mytilus edulis ; alleloenzymes ; enzyme kinetics ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two glucosephosphate isomerase (GPI;D-glucose-6-phosphate ketolisomerase; EC 5.3.1.9) alleloenzymes from the blue mussel,Mytilus edulis, were purified to homogeneity. The steady-state kinetic properties of GPI1.00 and GPI.96, which exhibit latitudinal clines in frequency along the Atlantic coast of North America, were determined in both the glycolytic and the gluconeogenic reaction directions at physiological temperatures and pH levels. The two alleloenzymes are catalytically similar at low temperatures (5–10°C), while GPI1.00 diverges to become more efficient at higher physiological temperatures (15–25°C). This pattern of differentiation is consistent with the latitudinal distributions of the alleloenzymes and is due to the greater temperature sensitivities of GPI1.00 V max /K m values of the two alleloenzymes are virtually the same over the physiological range of temperatures. The observed pattern of catalytic differentiation is similar to that seen for interspecific GPI variants.
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    Temperature-related kinetic differentiation of glucosephosphate isomerase alleloenzymes isolated from the blue mussel,Mytilus edulis (1985)
    Springer
    Biochemical genetics 23 (1985), S. 705-728 
    Details
    ISSN: 1573-4927
    Keywords: glucosephosphate isomerase (EC 5.3.1.9) ; Mytilus edulis ; alleloenzymes ; enzyme kinetics ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two glucosephosphate isomerase (GPI;D-glucose-6-phosphate ketolisomerase; EC 5.3.1.9) alleloenzymes from the blue mussel,Mytilus edulis, were purified to homogeneity. The steady-state kinetic properties of GPI1.00 and GPI.96, which exhibit latitudinal clines in frequency along the Atlantic coast of North America, were determined in both the glycolytic and the gluconeogenic reaction directions at physiological temperatures and pH levels. The two alleloenzymes are catalytically similar at low temperatures (5–10°C), while GPI1.00 diverges to become more efficient at higher physiological temperatures (15–25°C). This pattern of differentiation is consistent with the latitudinal distributions of the alleloenzymes and is due to the greater temperature sensitivities of GPI1.00 V max /K m values of the two alleloenzymes are virtually the same over the physiological range of temperatures. The observed pattern of catalytic differentiation is similar to that seen for interspecific GPI variants.
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    The NO2-O3 system at sub-ppm concentrations: Influence of temperature and relative humidity (1985)
    Springer
    Journal of atmospheric chemistry 2 (1985), S. 387-403 
    Details
    ISSN: 1573-0662
    Keywords: Night-time NO2 oxidation ; nitrate radical ; nitrogen pentoxide ; wall scavening ; stoichiometry ; kinetic study ; temperature ; relative humidity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The stoichiometry and kinetics of the reaction of NO2 with O3 at sub-ppm concentration level have been investigated as a function of temperature and relative humidity. The experiments were performed in a continuous flow reactor using chemiluminescent and wet chemical methods of analysis. The rate constant found can be described by the Arrhenius expression: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiaaik% dacaGGUaGaaGyoaiaaiEdacqGHXcqScaaIWaGaaiOlaiaaigdacaaI% 0aGaaiykaiabgEna0kaaigdacaaIWaWaaWbaaSqabeaacqGHsislca% aIXaGaaG4maaaakiaabwgacaqG4bGaaeiCaiaacIcadaWcgaqaaiaa% cIcacqGHsislcaaIYaGaaGOnaiaaikdacaaIWaGaeyySaeRaaGyoai% aaicdacaGGPaaabaGaamivaiaacMcacaqGGaGaae4yaiaab2gadaah% aaWcbeqaaiaabodaaaGccaqGGaWaaSGbaeaacaqGTbGaae4BaiaabY% gacaqGLbGaae4yaiaabwhacaqGSbGaaeyzamaaCaaaleqabaGaaeyl% aiaabgdaaaaakeaacaqGZbWaaWbaaSqabeaacaqGTaGaaeymaaaaaa% aaaaaa!62A3!\[(2.97 \pm 0.14) \times 10^{ - 13} {\text{exp}}({{( - 2620 \pm 90)} \mathord{\left/ {\vphantom {{( - 2620 \pm 90)} {T){\text{ cm}}^{\text{3}} {\text{ }}{{{\text{molecule}}^{{\text{ - 1}}} } \mathord{\left/ {\vphantom {{{\text{molecule}}^{{\text{ - 1}}} } {{\text{s}}^{{\text{ - 1}}} }}} \right. \kern-\nulldelimiterspace} {{\text{s}}^{{\text{ - 1}}} }}}}} \right. \kern-\nulldelimiterspace} {T){\text{ cm}}^{\text{3}} {\text{ }}{{{\text{molecule}}^{{\text{ - 1}}} } \mathord{\left/ {\vphantom {{{\text{molecule}}^{{\text{ - 1}}} } {{\text{s}}^{{\text{ - 1}}} }}} \right. \kern-\nulldelimiterspace} {{\text{s}}^{{\text{ - 1}}} }}}}\] and are independent of the relative humidity. As commonly encountered in previous studies a lower-than-two reaction stoichiometry is observed. Heterogeneous reactions occurring at the reactor wall seem to be essential in the reaction mechanism. The NO3 wall conversion to NO2 and the N2O5 wall scavenging in the presence of H2O are suggested to account for the observed stoichiometric factors.
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    Attraction of male spruce budworm moths,Choristoneura fumiferana (Clemens), to pheromone-baited traps in small-tree thinnings (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 125-133 
    Details
    ISSN: 1573-1561
    Keywords: Spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; sex pheromone ; small-tree thinnings ; temperature ; precipitation ; wind ; attraction distance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mean catches of spruce budworm,Choristoneura fumiferana (Clemens), moths were not significantly different among four small-tree thinning treatments of young spruce-fir-hemlock regeneration. Significant inverse relationships were found between trap catches and distances to nearby spruce-fir-hemlock overstory. Prevailing wind directions indicated that moths were attracted anemotactically to upwind pheromone sources. No definite trends were detected between catches and temperature or precipitation.
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    Effect of temperature on the occluding junctions of monolayers of epithelioid cells (MDCK) (1984)
    Springer
    The journal of membrane biology 79 (1984), S. 175-184 
    Details
    ISSN: 1432-1424
    Keywords: epithelial monolayers ; MDCK cells ; occluding junctions ; intramembrane particles ; electrical resistance ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary In previous works it was demonstrated that the monolayer of MDCK cells behaves as a leaky epithelium where the electrical resistance across reflects the sealing capacity of the occluding junction. In the present work we study whether this sealing capacity can be modified by temperature and whether this is accompanied by changes in the structure of the occluding junction. Monolayers were prepared on disks of nylon cloth coated with collagen and mounted as a flat sheet between two Lucite chambers. The changes in resistance elicited by temperature were large (306% between 3 and 37°C), fast (less than 2 sec), and reversible. An Arrhenius plot of conductance versus the inverse of temperature shows a broken curve (between 22 and 31°C), and the activation energies calculated (3.2 and 4.0 kcal·mol−1) fall within the expected values for processes of simple diffusion. The morphology of the occuluding the number of evaluated in freeze-fracture replicas by counting the number of strands and the width of the band occupied by the junction every 133 nm. In spite of the change by 306% of the electrical resistance and the phase transition, we were unable to detect any appreciable modification of the morphology of the occluding junction. Since the freeze-fracture replicas also show a density of intramembrane particles (IMP) different in the apical from that in the basolateral regions of the plasma membrane, as well as differences between faceE and faceP, we also investigated whether this is modified by temperature. Cold increases the population of IMP, but does not affect their polarization with the incubation time it takes to elicit changes in electrical resistance.
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    Effects of divalent cations, temperature, osmotic pressure gradient, and vesicle curvature on phosphatidylserine vesicle fusion (1984)
    Springer
    The journal of membrane biology 77 (1984), S. 265-275 
    Details
    ISSN: 1432-1424
    Keywords: vesicle fusion ; surface energy ; divalent cations ; osmotic pressure gradient ; temperature ; membrane curvature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Fusion of phosphatidylserine vesicles induced by divalent cations, temperature and osmotic pressure gradients across the membrane was studied with respect to variations in vesicle size. Vesicle fusion was followed by two different methods: 1) the Tb/DPA fusion assay, whereby the fluorescent intensity upon mixing of the internal aqueous contents of fused lipid vesicles was monitored, and 2) measurement of the changes in turbidity of the vesicle suspension due to vesicle fusion. It was found that the threshold concentration of divalent cations necessary to induce vesicle fusion depended on the size of vesicles; as the diameter of the vesicle increased, the threshold value increased and the extent of fusion became less. For the osmotic pressure-induced vesicle fusion, the larger the diameter of vesicles, the smaller was the osmotic pressure gradient required to induce membrane fusion. Divalent cations, temperature increase and vesicle membrane expansion by osmotic pressure gradient all resulted in increase in surface energy (tension) of the membrane. The degree of membrane fusion correlated with the corresponding surface energy changes of vesicle membranes due to the above fusion-inducing agents. The increase in surface energy of 9.5 dyn/cm from the reference state corresponded to the threshold point of phosphatidylserine membrane fusion. An attempt was made to explain the factors influencing fusion phenomena on the basis of a single unifying theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01870574
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    Far infrared remote sounding of stratospheric temperature and trace gas distributions (1984)
    Springer
    Journal of atmospheric chemistry 2 (1984), S. 145-161 
    Details
    ISSN: 1573-0662
    Keywords: Stratosphere ; remote sensing ; trace gases ; temperature ; Far infrared ; remote sensing ; stratosphere ; Spectroscopy ; stratosphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The thermal emission spectrum of the Earth's stratosphere in the far infrared exhibits rotational transitions of a large number of trace constituents in addition to the magnetic dipole lines of molecular oxygen. Stratospheric lines that have been identified in the far infrared spectrum include H2O, O3, HNO3, N2O, CO, HCl, HF, HCN and OH. This paper discusses the potential usefulness of far infrared thermal emission measurements for simultaneous retrieval of temperature and constituent distributions. A description of the high-resolution Michelson interferometer currently employed for balloon-borne far infrared stratospheric studies is given, along with a summary of the mode of limbscan observations and an example of an observed spectrum. Numerical results based on synthetic limb radiance data for model atmospheres are presented. Formal inversion techniques with a radiative transfer model based on line-by-line transmittance calculations are employed. Temperature profiles are retrieved from synthetic spectra by an inversion of the O2 magnetic dipole lines. Vertical trace gas mixing ratio profiles are determined from an analysis of the corresponding spectral emission features. Numerical results based on synthetic limb radiance data are presented in order to assess the retrieval accuracies of the temperature profiles and the vertical mixing ratio profiles of O3, HCl, and OH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114128
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    Growth analysis of corn and soybean response to allelopathic effects of weed residues at various temperatures and photosynthetic photon flux densities (1983)
    Springer
    Journal of chemical ecology 9 (1983), S. 1263-1280 
    Details
    ISSN: 1573-1561
    Keywords: Amaranthus retroflexus ; Setaria glauca ; allelochemicals ; temperature ; light condition ; Zea mays ; corn ; glycine max ; soybeans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The effects of redroot pigweed (Amaranthus retroflexus L.) and yellow foxtail [Setariaglauca (L.) Beauv.] residues on corn (Zea mays L.) and soybeans [Glycine max (L.) Merr.] were evaluated at various temperatures and photosynthetic photon flux densities (PPFD) in a Biotron. Mathematical growth analysis techniques were used for the evaluation. Redroot pigweed markedly reduced leaf area duration (LAD), leaf weight ratio (LWR), and total dry matter production in both crops. Yellow foxtail residue inhibited total dry matter production in corn and soybeans 20 and 30 days after planting (DAP). It also reduced growth rate (GR) and LAD in corn and biomass increment (Δ W) in soybeans. Biomass increment was more closely correlated to LAD than net assimilation rate (NAR) in soybeans, whereas in corn NAR contributed more to Δ W than LAD. The 30/20 ° C temperature with a PPFD of 380 μE/m2/sec produced a larger Δ W with a greater NAR and larger LAD in corn, resulting in maximum dry matter accumulation than 20/10 ° C and other levels of PPFD. Under similar conditions, soybeans showed little or no response to the changes. The results demonstrate the allelopathic effects of weed residues on growth and dry matter production, affecting LAD, LWR, and GR. The results also show that environmental temperature and PPFD may alter the allelopathic effects of weeds on crops. The possible interference with photosynthesis and the partitioning of biomass into leaf component relative to the total biomass produced by the plant may be the inhibitory effects of allelochemicals present in redroot pigweed and yellow foxtail residues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00982228
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    Temperature dependence of liquid epoxy resin impregnation through polyester non-woven fabric (1983)
    Springer
    Colloid & polymer science 261 (1983), S. 834-845 
    Details
    ISSN: 1435-1536
    Keywords: Impregnation ; capillary ; liquid ; fabric ; temperature
    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 temperature dependence of liquid epoxy resin impregnation under atmospheric pressure was measured under the condition that the impregnation was through polyester non-woven fabric sheets, sandwiched between two circular glass plates. It was expected that impregnation would take place to a small extent, because the pressure in the sheet increases to more than atmospheric pressure in the course of impregnation from the perimeter of the circular sheet toward its center, but the liquid resin impregnates to a great extent and impregnating velocity increases with a rise in temperature. This phenomenon can be analyzed by the Kozeny-Carman equation improved by the introduction of the theoretically calculated capillary force in the modeled fiber bed structure and a parameter to postulate gas solubility and diffusion into the liquid resin. An increase in the impregnating velocity with the temperature rise is caused by decrease in the resin viscosity, by increase of the capillary force pressure and by decrease in the gas pressure corrected by a parameter.
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    URL: http://dx.doi.org/10.1007/BF01421437
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    Selection at the alcohol dehydrogenase locus of Drosophila melanogaster: Effects of ethanol and temperature (1982)
    Springer
    Biochemical genetics 20 (1982), S. 681-688 
    Details
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; Drosophila ; selection ; ethanol ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Drosophila melanogaster larvae were subjected to 10 generations of selection on 6% ethanol at 17, 25, and 30°C. For each temperature there was a significant (P〈0.01) increase in the frequency of the Adh isoallele. Controls with no ethanol showed no change in the frequency of the Adh F isoallele. Larvae subjected to stronger selection on 8% ethanol confirmed the results. When adults of various ages were subjected to 16 and 32°C, the ADHF isoenzyme retained its twofold advantage in activity over ADHS regardless of the temperature. The same result was obtained with larvae at 16 and 35°C. Although some effect of temperature was demonstrated, it was concluded that the effect was not strong enough for temperature to be a selective factor under the conditions studied. However, ethanol is a strong selective factor for laboratory populations.
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    URL: http://dx.doi.org/10.1007/BF00483965
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    Pressure dependence of the sodium currents of squid giant axon (1982)
    Springer
    The journal of membrane biology 69 (1982), S. 23-34 
    Details
    ISSN: 1432-1424
    Keywords: axon ; hydrostatic pressure ; Na currents ; kinetics ; temperature ; activation volume
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The effects of hydrostatic pressures up to 62 MPa upon the voltage-clamp currents of intact squid giant axons were measured using mineral oil as the pressure transmitting medium. The membrane resistance and capacitance were not appreciably affected over the whole range of pressures explored. The predominant effect of pressure is to slow the overall kinetics of the voltage-clamp currents. Both the early (Na) currents and the delayed (K) ones were slowed down by approximately the same time scale factor, which was in the range of 2 to 3 when pressure was increased from atmospheric to 62 MPa. Finer details of the effects, most evident at moderate depolarizations, are: the apparent initial delay in the turn-on of Na currents is increased by pressureless than is the phase of steepest time variation, and the later decay is slowedmore than is the rising phase. The initial time course of the currents at high pressures can be made to overlap with that at normal pressure by a constant time compression factor, Θm, together with a small, voltage-dependent delay. In a given axon, Θm was fairly independent of voltage, and it increased exponentially with pressure according to an apparent activation volume, ΔV∓, ranging between 32 and 40 cm3/mole. ΔV∓ tended to decrease with increasing temperature. Contrary to what is observed for moderate or large depolarizations, the kinetics of Na inactivation produced by conditioning prepulses of −50 or −60 mV was little affected over the whole range of pressures explored. Inferences about the pressure dependence of the steady-state Na activation were made from the comparison of the plots of early peak currents,I p, versus membrane potential,E. The Na reversal potential,E Na, and the slope of the plots nearE Na did not change significantly with pressure, but the peak Na conductancevs. E relationship was shifted by about +9 mV upon increasing pressure to 62 MPa. Steady-state Na inactivation,h ∞, was slightly affected by pressure. At 62 MPa the midpoint potential of theh ∞ (E) curve,E h, was shifted negatively by about 4 mV, while the slope atE h decreased by about 38%. Under the tentative assumption that pressure directly affects the gating of Na channels, the Na activation data follows a simple Hodgkin-Huxley scheme if the opening of anm gate involves an activation volume of about 58 Å3 and a net volume increase of about 26 Å3. However, a self-consistent description of the totality of the effects of pressure on Na inactivation cannot be obtained within a similar simple context.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01871238
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    Viscosity of aqueous solutions of univalent electrolytes from 5 to 95°C (1980)
    Springer
    Journal of solution chemistry 9 (1980), S. 19-35 
    Details
    ISSN: 1572-8927
    Keywords: Viscosity ; automatic viscometer ; aqueous solution ; univalent electrolyte ; Jones-DoleB andD coefficient ; temperature ; coefficient ; water structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Viscosity measurements of a series of univalent electrolytes in water have been performed with an automatic dual viscometer system, covering the temperature range of 5 to 95°C. Results are discussed in terms of Jones-DoleB andD coefficients. TheB coefficients of the salts are divided into their ionic contributions according toB(K+)=B(Cl−) at all temperatures. On a simple model intrinsic and structural contributions inB are calculated for the different ions. The structural term depends exponentially on the temperature in a unique manner, independent of the ion (except for Li+).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00650134
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    Ultraviolet spectroscopic study of ferric hydroxide complexation (1978)
    Springer
    Journal of solution chemistry 7 (1978), S. 373-383 
    Details
    ISSN: 1572-8927
    Keywords: Ferric ; hydrolysis ; ionic strength ; temperature ; enthalpy ; ferric hydroxide ; ultraviolet ; spectroscopic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Ultraviolet absorbance spectra of ferric ions in 0.68m NaClO4 were studied as a function of pH at 4.0, 14.9, and 25.0°C. The results provided an evaluation of the stability constant for the formation of FeOH2+ which is *β1=[FeOH +][H +]/[Fe 3+]. The enthalpy change for the reaction Fe3++H2O⇌ FeOH2++H+ was calculated as 10.0±0.3 kcal-mole−1. Increasing temperature was also found to promote the reaction Fe3++2H2O⇌ Fe(OH) 2 + +2H+. Our results were combined with the results of other to produce an expression describing the first hydrolysis equilibrium at ionic strengths between 0 and 3m and temperatures between 4.0 and 45.0°C at 1 atm total pressure. At 25°C and 0.68m the ionic strength *β1=1.90×10-3
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    URL: http://dx.doi.org/10.1007/BF00662897
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