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  • Analytical Chemistry and Spectroscopy  (5)
  • tetraphenylphosphonium ion  (3)
  • Earthworms  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Partial molar heat capacities of selected electrolytes and benzene in methanol and dimethylsulfoxide at 25, 40, and 80°C (1987)
    Springer
    Journal of solution chemistry 16 (1987), S. 885-906 
    Details
    ISSN: 1572-8927
    Keywords: Heat capacities ; flow calorimetry ; densities ; partial molar heat capacities ; alkali metal ions ; halide ions ; tetraphenylphosphonium ion ; tetraphenylborate ion ; single ion values ; methanol ; dimethylsulfoxide ; Debye-Hückel limiting law slopes ; electrostriction and charge effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A high temperature-high pressure flow heat capacity calorimeter, designed to operate to 350°C and 20 Mpa, has been constructed and tested with aqueous sodium chloride solutions to 80°C. The calorimeter has been used to measure the specific heats for solutions of NaBr, NaClO4, φ4PBR, NaBφ4, and benzene in methanol (MeOH) and dimethylsulfoxide (DMSO) at 40 and 80°C. A commercial calorimeter was used to measure the same systems at 25°C. Apparent molar heat capacities C〉p,ϕ have been evaluated and extrapolated to infinite dilution to obtain standard partial molar heat capacities $$\bar C_{p,2}^{\text{o}} $$ . For electrolytes $$\bar C_{p,2}^{\text{o}} $$ are positive and insensitive to temperature to 80°C in DMSO, but in MeOH, C p, 2 0 for simple electrolytes are negative and become increasingly negative with temperature. The behavior in MeOH is attributed to strong electrostriction by ionic charge and solvation of anions by MeOH molecules which increases with temperature. This is similar to observed behavior of electrolytes in water above 100°C. For benzene $$\bar C_{p,2}^{\text{o}} $$ is positive in MeOH and DMSO, and increases with temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00650993
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  • 2
    Electronic Resource
    Electronic Resource
    Isentropic compressibilities of univalent electrolytes in methanol at 25°C (1984)
    Springer
    Journal of solution chemistry 13 (1984), S. 699-720 
    Details
    ISSN: 1572-8927
    Keywords: Apparent molar isentropic compressibility ; apparent molar volume ; electrolytes ; tetraalkylammonium ions ; tetraphenylphosphonium ion ; methanol ; single ion values ; Debye-Huckel limiting law
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A flow densimeter and an ultrasonic sound velocimeter have been used to measure densities and isentropic compressibilities of solutions of LiBr, NaCl, NaBr, Nal, KF, KCl, KBr, Kl, RbBr, Rbl, CsF, CsBr, Ph 4 PBr, and NaBPh 4 in anhydrous methanol at 25°C. the latter two electrolytes were also investigated in water at 25°C. Concentrations ranged from about 0.005 m to above 0.25m, solubility permitting. Apparent molar isentropic compressibilities, KS,ϕ, have been calculated and extrapolated to infinite dilution to obtain K S,ϕ o . The K S,ϕ o values in methanol are all negative, and significantly more negative than the corresponding data in water. Additional data from the literature for acetonitrile and ethanol solutions show that K S,ϕ o for the alkali metal halides become more negative in direct proportion to increasing solvent isentropic compressibility. Furthermore, the dependence of K S,ϕ o in ionic size also varies in proportion to solvent isentropic compressibility. An explanation of this behavior is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00649010
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  • 3
    Electronic Resource
    Electronic Resource
    Partial molar isentropic compressibilities and volumes of selected electrolytes and nonelectrolytes in dimethylsulfoxide (1987)
    Springer
    Journal of solution chemistry 16 (1987), S. 753-765 
    Details
    ISSN: 1572-8927
    Keywords: Densities ; sound velocites ; partial molar volumes and isentropic compressibilities ; alkali metal ions ; halide ions ; tetraphenylphosphonium ion ; tetraphenylborate ion ; single ion values, DMSO, and Debye-Huckel limiting law slopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Precision densities and sound velocities for solutions of selected univalent electrolytes and nonelectrolytes in DMSO have been measured at 25°C, and apparent molar isentropic compressibilities and volumes evaluated. The data were extrapolated to infinite dilution to obtain standard state partial molar quantities, K s,2 ° , and V 2 ° . Values of V 2 ° and K s,2 ° for alkali metal halides in DMSO are very similar to those in water. The results confirm conclusions derived from data in water and other nonaqueous solvents that K s,2 ° and V 2 ° for alkali metal halides are strongly dependent on solvent compressibility. K s,2 ° becomes more negative and V 2 ° decreases as solvent compressibility increases. Attempts to determine ionic K s,2 ° values suggest that a significant dissymmetry exists between φ4P+ and φ4B− in DMSO, whereas in water and MeOH, these large ions appear to behave similarly. Ionic V 2 ° values support this conclusion. Steric hindrance in the DMSO molecule is believed to be responsible for this dissymmetry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00652578
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  • 4
    Electronic Resource
    Electronic Resource
    The role of the earthworm Lumbricus terrestris in the transport of bacterial inocula through soil (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 132-139 
    Details
    ISSN: 1432-0789
    Keywords: Key words Bacterial inocula lux modified ; Pseudomonas fluorescens ; Repacked soil microcosms ; Earthworms ; Lumbricus terrestris ; Leaching patterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two laboratory experiments were used to investigate the effect of the earthworm Lumbricus terrestris on transport of genetically marked Pseudomonas fluorescens inocula through soil microcosms. The microcosms comprised cylindrical cores of repacked soil with or without earthworms. Late log-phase cells of P. fluorescens, chromosomally marked with lux genes encoding bioluminescence, were applied to the surface of soil cores as inoculated filter paper discs. In one experiment, 5 and 10 days after inoculation, cores were destructively harvested to determine concentrations of marked pseudomonads with depth relative to the initial inoculum applied. Transport of the bacteria occurred only in the presence of earthworms. In a second experiment cores were subjected to simulated rainfall events 18 h after inoculation with lux-marked bacteria at 3-day intervals over a 24-day period. Resulting leachates were analysed for the appearance of the marked bacteria, and after 28 days cores were destructively harvested. Although some marked cells (less than 0.1% of the inoculum applied) were leached through soil in percolating water, particularly in the presence of earthworms, the most important effect of earthworms on cell transport was through burial of inoculated litter rather than an increase in bypass flow due to earthworm channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336053
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  • 5
    Electronic Resource
    Electronic Resource
    The role of the earthworm Lumbricus terrestris in the transport of bacterial inocula through soil (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 132-139 
    Details
    ISSN: 1432-0789
    Keywords: Bacterial inocula lux modified ; Pseudomonas fluorescens ; Repacked soil microcosms ; Earthworms ; Lumbricus terrestris ; Leaching patterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two laboratory experiments were used to investigate the effect of the earthworm Lumbricus terrestris on transport of genetically marked Pseudomonas fluorescens inocula through soil microcosms. The microcosms comprised cylindrical cores of repacked soil with or without earthworms. Late log-phase cells of P. fluorescens, chromosomally marked with lux genes encoding bioluminescence, were applied to the surface of soil cores as inoculated filter paper discs. In one experiment, 5 and 10 days after inoculation, cores were destructively harvested to determine concentrations of marked pseudomonads with depth relative to the initial inoculum applied. Transport of the bacteria occurred only in the presence of earthworms. In a second experiment cores were subjected to simulated rainfall events 18 h after inoculation with lux-marked bacteria at 3-day intervals over a 24-day period. Resulting leachates were analysed for the appearance of the marked bacteria, and after 28 days cores were destructively harvested. Although some marked cells (less than 0.1% of the inoculum applied) were leached through soil in percolating water, particularly in the presence of earthworms, the most important effect of earthworms on cell transport was through burial of inoculated litter rather than an increase in bypass flow due to earthworm channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336053
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  • 6
    Electronic Resource
    Electronic Resource
    Gas chromatography/mass spectrometric analysis of urinary nucleosides in cancer patients; potential of modified nucleosides as tumour markers (1993)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 7 (1993), S. 427-434 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Analysis of urine from cancer patients by capillary gas chromatography/mass spectrometry positively identified 14 urinary nucleosides including several modified nucleosides. Levels of the modified nucleosides 1-methyl-adenosine, 2-methylguanosine, N2,N2-dimethylguanosine and 1-methylinosine as well as the total nucleoside level were elevated in the urine when a malignant tumour was present; the levels of N2,N2-dimethylguanosine were found to correlate with the stage of the cancer.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290070605
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  • 7
    Electronic Resource
    Electronic Resource
    Analysis of cyclic nucleotide-related enzymes by continuous-flow fast-atom bombardment mass spectrometry (1993)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 7 (1993), S. 293-303 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Continuous-flow fast-atom bombardment mass Spectrometry has been developed to directly monitor cyclic nucleotide (substrate) and its product levels from an on-going phosphodiesterase reaction. Analysis of cAMP and cCMP phosphodiesterase incubates have been performed where the temporal evolution of the enzymic reaction is monitored and the effect of enzyme concentration upon the rate of reaction determined. Quantitative data on the enzyme kinetics have been obtained, in the form of Lineweaver-Burke plots, that are shown to correlate well with well-established radiometric methods.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290070407
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  • 8
    Electronic Resource
    Electronic Resource
    Quantitation by fast-atom bombardment mass spectrometry: Assay of cytidine 3′, 5′ -cyclic monophosphate-responsive protein kinase (1992)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 6 (1992), S. 601-607 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A protein kinase, stimulated by cytidine 3′, 5′ -cyclic monophosphate, is conventionally assayed by monitoring the incorporation of radiolabelled phosphate from adenosine triphosphate into a histone substrate. Here the assay of the protein kinase is carried out by positive-ion fast-atom bombardment mass spectrometric analysis of the enzyme incubation mixture after the reaction has been terminated. The data so obtained show good agreement with data obtained by the conventional radiometric assay: the intrinsic advantage of the mass spectrometric assay is the capacity for multiple component monitoring; the ability of the kinase to bind competing cyclic nucleotides togeter with integral adenosine triphosphatase (ATPase) and phosphodiesterase activity can also be assessed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290061004
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  • 9
    Electronic Resource
    Electronic Resource
    Fast-atom bombardment mass spectrometric analysis of cyclic nucleotide and nucleotide triphosphate analogues used in studies of cyclic nucleotide-related enzymes (1993)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 7 (1993), S. 725-733 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Two isomers of adenosine 3′,5′-cyclic monophosphate, which show agonist and antagonist activity with cyclic AMP-dependent protein kinase, were found to yield essentially identical positive-ion fast-atom bombardment (FAB) mass spectra, but S1 and S2 fragments of differing relative intensities in their collision-induced dissociations, studied using mass-analysed ion kinetic energy (CID/MIKE) spectra. Halogen-substituted cyclic nucleotides, used in differentiating between protein kinase cyclic nucleotide binding sites, produced FAB mass spectra and CID/MIKE spectra with fragmentations generally analogous to those of the parent cyclic nucleotides; the bromo-derivatives showed a greater propensity for dehalogenation than the chloro-derivatives. The adenosine triphosphate analogues, adenylyl-(β,γ-methylene)-diphosphate and adenylyl-imidodiphosphate, alternative substrates for adenylyl cyclase, showed similar fragmentations with the methylene and imido groups blocking cleavage between the β and γ phosphate groups. The fragmentations observed are discussed in the context of the use of these compounds in the assay of protein kinase and adenylyl cyclase activity by quantitative mass spectrometry.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290070809
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  • 10
    Electronic Resource
    Electronic Resource
    Determination of enzyme kinetic parameters of cyclic CMP-specific phosphodiesterase by quantitative fast atom bombardment tandem mass spectrometry (1991)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 26 (1991), S. 447-453 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The determination of cytidine 3′,5′-cyclic monophosphate-specific phosphodiesterase activity by means of fast-atom bombardment (FAB) mass Spectrometry with mass-analysed ion kinetic energy (MIKE) spectrum scanning is described. Initial efforts to determine the activity of the enzyme by this method were unsuccessful owing to the obfuscation of sample-related peaks by peaks emanating from the incubation buffer and cation adducts; dilution of buffer and a desalting procedure overcame these difficulties. In the resulting positive-ion FAB mass spectra, characteristic peaks of the enzyme substrate and product could be readily identified and the protonated molecular ions selected for MIKE scanning. By spiking enzyme incubates with known amounts of substrate and product, and measuring peak heights in the MIKE spectra of both spiked and unspiked samples, the substrate/product ratio at the end of a series of phosphodiesterase incubations was determined. From the data obtained, the Km and Vmax of the phosphodiesterase were calculated as 6.08 mM and 11 μmol min-1 mg-1, respectively, showing good agreement with the analogous values of 8.06 mM and 5.8 μmol-1 min-1 mg-1 obtained by radioactive assay.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210260514
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