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  • 1
    Electronic Resource
    Electronic Resource
    Clinical chemistry (1991)
    s.l. : American Chemical Society
    Analytical chemistry 63 (1991), S. 165-270 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00012a011
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  • 2
    Electronic Resource
    Electronic Resource
    Preparation and evaluation of a bimodal size-exclusion chromatography column containing a mixture of two silicas of different pore diameter (1991)
    s.l. : American Chemical Society
    Analytical chemistry 63 (1991), S. 1350-1354 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00014a003
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Liquid chromatographic retention behavior of polystyrene homopolymers on a C4, bimodal pore diameter, reversed-phase column (1992)
    s.l. : American Chemical Society
    Analytical chemistry 64 (1992), S. 16-21 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00025a004
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  • 4
    Electronic Resource
    Electronic Resource
    Non-RRKM kinetics in gas-phase SN2 nucleophilic substitution (1990)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 94 (1990), S. 6148-6150 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100379a002
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  • 5
    Electronic Resource
    Electronic Resource
    Trajectory studies of SN2 nucleophilic substitution. I. Dynamics of Cl−+CH3Cl reactive collisions (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 7962-7980 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Classical trajectories were used to study the dynamics of the Cl−+CH3Cl→Cl−---CH3Cl association and the Cl−+CH3Cl→ClCH3+Cl− substitution reactions. Substantial deviations are found between the underlying microscopic dynamics of the reactions and the assumptions of statistical rate theories. The energy dependence of the trajectory rate constant for the majority of Cl−---CH3Cl→Cl−+CH3Cl dissociation is in accord with a model in which only the Cl−---C stretch and the two Cl−---CH3Cl bend modes are active degrees of freedom. At 300 K the trajectory rate constant for Cl−+CH3Cl→Cl−---CH3Cl association is approximately forty percent smaller than that of microcanonical variational transition state theory, with the difference increasing with an increase in temperature. For thermal conditions substitution occurs by an indirect mechanism in which the reactive system is initially trapped in the Cl−---CH3Cl potential well. The cross section for this process decreases dramatically as the reactant relative translational energy is increased. The effect of rotational energy is less precipitous. Exciting the C–Cl stretch normal mode of CH3Cl opens up a direct substitution mechanism without trapping in either of the two potential wells. There is a significant decrease in the cross section for this direct substitution when CH3Cl is rotationally excited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459326
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  • 6
    Electronic Resource
    Electronic Resource
    Trajectory studies of SN2 nucleophilic substitution. II. Nonstatistical central barrier recrossing in the Cl−+CH3Cl system (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 8275-8287 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: For the Cl−+CH3Cl SN2 nucleophilic substitution reaction transition-state theory predicts that crossing the central barrier region of the potential-energy surface is the rate-controlling step. In this work classical trajectories are initialized at the central barrier. Four different models are considered for the potential-energy surface. A significant amount of central barrier recrossing is observed in the trajectories, which suggests that transition-state theory is an incomplete model for calculating the Cl−+CH3Cl SN2 rate constant. Two types of recrossings are observed in the trajectories: intermediate recrossings in which trajectories linger near the central barrier and complex recrossings in which trajectories trapped in the Cl−⋅⋅⋅CH3Cl complex return to the central barrier region. Intermediate recrossings are important if, in the trajectory initial conditions, zero-point energy is added to the vibrational modes orthogonal to the reaction coordinate. Rice–Ramsperger–Kassel–Marcus (RRKM) theory predicts extensive dissociation of the Cl−⋅⋅⋅CH3Cl complex to Cl−+CH3Cl and negligible complex recrossings in the trajectory calculations. In contrast to this prediction, negligible Cl−+CH3Cl formation is observed and continual complex recrossings occur, on a time scale longer than the complex's RRKM lifetime. These results indicate the ergodic assumption is invalid for the Cl−⋅⋅⋅CH3Cl complex. Phase-space bottlenecks which give rise to the intermediate and complex recrossings are considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.462331
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  • 7
    Electronic Resource
    Electronic Resource
    Monitoring an Arizona Ponderosa Pine Restoration: Sampling Efficiency and Multivariate Analysis of Understory Vegetation (2004)
    Oxford, UK; Malden, USA : Blackwell Science Inc
    Restoration ecology 12 (2004), S. 0 
    Details
    ISSN: 1526-100X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: As monitoring plans for the restoration of Pinus ponderosa forests in the southwestern United States evolve toward examining multifactor ecosystem responses to ecological restoration, designing efficient sampling procedures for understory vegetation will become increasingly important. The objective of this study was to compare understory composition and diversity among thin/burn and control treatments in a P. ponderosa restoration, while simultaneously examining the effects of sampling design and multivariate analyses on which conclusions were based. Using multi-response permutation procedures (MRPP), we tested the null hypothesis of no difference in understory species composition among treatments using different data matrices (e.g., frequency and cover) for two different sampling methods. Treatment differences were subtle and were detected by an intensive 50, 1-m2 subplot sampling method for all data matrices but were not detected by a less intensive point-intercept sampling method for any matrix. Sampling methods examined in this study controlled results of multivariate analyses more than the data matrices used to summarize data generated by a sampling method. We partitioned data into plant life form and native/exotic species categories for MRPP, and this partitioning isolated plant groups most responsible for treatment differences. We also examined the effects of number of 1-m2 subplots sampled on mean-species-richness/m2 estimates and found that estimates based on 10 subplots and based on 50 subplots were highly correlated (r = 0.99). Species–area curves indicated that the 50, 1-m2 subplot sampling method detected the common species of sites but failed to detect the majority of rare species. Additional sampling-design studies are needed to develop single sampling designs that produce multifactor data on plant composition, diversity, and spatial patterns amenable to multivariate analyses as part of monitoring plans of vegetation responses to ecological restoration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1061-2971.2004.00317.x
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  • 8
    Electronic Resource
    Electronic Resource
    Development and use of an ultra thin fiber-reinforced denture palate (2002)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of prosthodontics 11 (2002), S. 0 
    Details
    ISSN: 1532-849X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1532-849X.2002.328_35.x
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  • 9
    Electronic Resource
    Electronic Resource
    Differential Effects of Acidic and Basic Fibroblast Growth Factors on Spinal Cord Cholinergic, GABAergic, and Glutamatergic Neurons (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 57 (1991), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: When spinal cord cultures from embryonic day 12 rats were cultured at low density, both acidic and basic fibroblast growth factors significantly increased neuronal survival and neurite outgrowth in a dose-dependent manner. The effects of acidic fibroblast growth factor were independent of heparin, in contrast to its mitogenic effects on both NIH3T3 cells and cerebral cortical astrocytes. In high-density cultures, acidic fibroblast growth factor increased choline acetyltransferase activity by 57%, glutamic acid decarboxylase activity by 58%, and aspartate aminotransferase activity by 65%. Basic fibroblast growth factor increased choline acetyltransferase activity by 73% and glutamic acid decarboxylase activity by 200% but decreased aspartate aminotransferase activity by 40%. Growing these cultures in the presence of a mitotic inhibitor did not significantly alter the effect of acidic or basic fibroblast growth factor on these enzyme activities. These results demonstrate that acidic and basic fibroblast growth factors differentially affect neurotransmitter enzyme levels of multiple classes of neurons, rather man having effects on a single neuronal population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1991.tb02121.x
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  • 10
    Electronic Resource
    Electronic Resource
    The psychophysiology of disgust: Differentiating negative emotional contexts with facial EMG (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 30 (1993), S. 0 
    Details
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: The goals of this study were (a) to examine differing views on the relationship between self-report of emotion and physiological expression of emotion, (b) to differentiate between negative emotional contexts during imagery using facial electromyogram (EMG), and (c) to describe the facial muscle patterning and autonomic physiology of situations that involve expelling or avoiding disgusting sensory stimulation. Fifty subjects imagined situations eliciting disgust, anger, pleasure, and joy in 8-s trials using a tone-cued imagery procedure. Heart rate, skin conductance level, and facial EMG at the corrugator, zygomatic, and levator labii superioris/alesque muscle regions were recorded during imagery, and self-reports of emotion were collected after imagery trials. Self-reports of emotion produced results consistent with the affective categorization of the images. Activity at the levator labii region was higher during disgust than during anger imagery. Corrugator region increase characterized the negative as compared with the positive emotional contents, and activity at the zygomatic region was higher during joy imagery than during the other three emotions. Heart rate acceleration was greater during disgust, anger, and joy imagery than during pleasant imagery. Disgust imagery could be discriminated from anger imagery using facial EMG, and the expressive physiology of disgust was occasioned by the action set of active avoidance or rejection of sensory stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1469-8986.1993.tb03354.x
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