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  • 2000-2004  (4)
  • 1955-1959  (4)
  • 1925-1929  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Temperature and density dependent solute vibrational relaxation in supercritical fluoroform (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 115 (2001), S. 4689-4695 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Temperature- and density-dependent vibrational relaxation data for the v6 asymmetric stretch of W(CO)6 in supercritical fluoroform (trifluoromethane, CHF3) are presented and compared to a recent theory of solute vibrational relaxation. The theory, which uses thermodynamic and hydrodynamic conditions of the solvent as input parameters, shows very good agreement in reproducing the temperature- and density-dependent trends of the experimental data with a minimum of adjustable parameters. Once a small number of parameters are fixed by fitting the functional form of the density dependence, there are no adjustable parameters in the calculations of the temperature dependence. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1389853
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  • 2
    Electronic Resource
    Electronic Resource
    Vibrational dynamics of large hot molecules in the collisionless gas phase (2002)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 116 (2002), S. 3540-3553 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Infrared ps pump-probe experiments are presented for the P, Q, and R rotational branches of the asymmetric CO stretching mode of tungsten hexacarbonyl (1997 cm−1) in the collisionless gas phase. The pump-probe decays are tri-exponentials (140 ps, 1.3 ns, and 〉100 ns) in contrast to single exponential decays observed in supercritical fluids and liquid solvents. The 1.3 ns decay component is the vibrational energy relaxation (VER) time. The long component occurs following intramolecular VER into a distribution of low-frequency modes. After VER is complete, the R signal is 48%, the Q signal is 29%, and the P signal is −10% (absorption increase) compared to the t=0 signal. These long-lived signals result from an increase in the occupation numbers of low-frequency modes (internal heating) that causes a shift of the vibrational spectrum. The fastest decay is produced by spectral diffusion. The spectrally narrow pump pulse burns a hole in the inhomogeneous ground state spectrum and generates a narrow spectral population in the excited state (excited state peak). The inhomogeneity arises from the distribution of occupation numbers of the low-frequency modes that produces different combination band spectral shifts. Spectral diffusion is caused by the time evolution of the complex low-frequency thermal vibrational wave packet. Two possible models for the spectral diffusion are evaluated, one in which spectral diffusion reduces the pump-probe signal by hole filling and broadening of the excited state peak, and one in which the spectral diffusion only broadens the excited state peak. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1446850
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    High-salt diet and responses of the pressurized mesenteric artery of the dog to noradrenaline and acetylcholine (2004)
    Oxford, UK : Blackwell Science Pty
    Clinical and experimental pharmacology and physiology 31 (2004), S. 0 
    Details
    ISSN: 1440-1681
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: 1. A high-salt diet in rats has been shown to result in enhanced vasoconstrictor and/or reduced vasodilator responses of isolated arteries to agonists. The present experiments were designed to investigate the effects of dietary salt on the responses of the pressurized mesenteric resistance artery of the dog to constrictor and dilator agents.2. Dogs were fed diets containing three different levels of salt with sodium concentrations (in mmol/kg per day) of 0.4 (low salt; LS), 3.0 (intermediate salt; IS) and 6.0 (high salt; HS) for a period of 4 weeks. At the end of the feeding period, animals were killed and lengths of third-order mesenteric artery were obtained and mounted in a perfusion myograph and changes in internal diameter were measured using a microscope and video-tracking device. The responses to noradrenaline (NA), acetylcholine (ACh) and sodium nitroprusside (SNP) were then determined.3. The vasoconstrictor responses to NA were identical in the three groups. However, the relaxation response of the vessels to ACh was attenuated in HS dogs compared with LS dogs (P 〈 0.05), but not with IS dogs. The application of NG-nitro-l-arginine methyl ester, an inhibitor of nitric oxide synthase, reduced the relaxation responses to ACh comparably in all three groups. The relaxation responses of the vessels to SNP were similar in all groups.4. These results indicate that, in the dog mesenteric resistance artery, a high-salt diet does not affect vasoconstrictor responses to NA, but does attenuate the vasorelaxant action of ACh, largely by inhibiting the production of endothelium-derived relaxing factor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1440-1681.2004.04069.x
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Effect of Inhibition of Cholinesterase on the Motility of the Small Intestine (1955)
    [s.l.] : Nature Publishing Group
    Nature 176 (1955), S. 468-469 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Later experiments indicated that the contractions of the longitudinal muscle of the small intestine were increased by diisopropyl phosphonofluoridate in amounts which did not cause more than 20 per cent inhibition of the true cholinesterase while inhibiting the pseudocholinesterase almost ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/176468a0
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  • 5
    Electronic Resource
    Electronic Resource
    Metabolism of Triaryl Phosphates in Rodents (1955)
    [s.l.] : Nature Publishing Group
    Nature 176 (1955), S. 259-260 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] It had been shown previously by Gross and Grosse4 that, two hours after intravenous injection of tri-o-cresyl phosphate into rabbits, an amount of cresol ester equivalent to 70 per cent of the administered compound can be recovered from the intestinal tract and an amount equivalent to 50 per cent ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/176259a0
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    Identification of Pseudocholinesterase in the Tissues of Ruminants (1955)
    [s.l.] : Nature Publishing Group
    Nature 176 (1955), S. 783-784 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] A study of the characteristics of the cholinesterases in ox spleen has shown that approximately 90 percent of the activity towards butyrylcholine (0-03 M) is due to a pseudocholinesterase, and the remaining 10 per cent to one of the unidentified eserine-resistant enzymes similar to those found in ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/176783b0
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    Paper (German National Licenses)
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  • 7
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    Unknown
    Secrets of State (1927)
    Philadelphia : Periodicals Archive Online (PAO)
    Social studies. 18:8 (1927:Dec.) 361 
    Details
    ISSN: 0037-7996
    Topics: History
    URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pao:&rft_dat=xri:pao:article:3111-1927-018-08-000001
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  • 8
    Electronic Resource
    Electronic Resource
    Hydrolysis of Adenosine Triphosphate by Mitochondrial Preparations (1957)
    [s.l.] : Nature Publishing Group
    Nature 179 (1957), S. 363-364 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] LIVER mitochondria, freshly prepared in isotonic sucroso, are unable to hydrolyse adenosine tri-phosphate at an appreciable rate1, but acquire this property upon the addition of dinitrophenol, or after various treatments which damage the structure of the mitochondria. Coincident with the ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/179363a0
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    Paper (German National Licenses)
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  • 9
    Electronic Resource
    Electronic Resource
    Derivatives of Spatial Variances of Growing Windows and the Variogram (2000)
    Springer
    Mathematical geology 32 (2000), S. 851-871 
    Details
    ISSN: 1573-8868
    Keywords: scales ; multiresolution ; moving windows ; regularized variograms ; spatial variances ; spatial covariances
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract Geostatistical analysis of spatial random functions frequently uses sample variograms computed from increments of samples of a regionalized random variable. This paper addresses the theory of computing variograms not from increments but from spatial variances. The objective is to extract information about the point support space from the average or larger support data. The variance is understood as a parametric and second moment average feature of a population. However, it is well known that when the population is for a stationary random function, spatial variance within a region is a function of the size and geometry of the region and not a function of location. Spatial variance is conceptualized as an estimation variance between two physical regions or a region and itself. If such a spatial variance could be measured within several sizes of windows, such variances allow the computation of the sample variogram. The approach is extended to covariances between attributes that lead to the cross-variogram. The case of nonpoint sample support of the blocks or elements composing each window is also included. A numerical example illustrates the application of this conceptualization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007548507649
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