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  • 1
    Electronic Resource
    Electronic Resource
    Cross polarization induced by temporary adsorption: NMR investigations on nanocapsule dispersions (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 4242-4250 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Nanocapsule dispersions are investigated by 1H–13C cross polarization experiments. The capsule walls, made up from polybutylcyanoacrylate, are detectable merely as a solid state signal, whereas the triglyceride forming the liquid core and the surfactant on the outside of the capsules give rise to narrow resonance lines in the cp-spectrum indicating their mobility. In order to clarify the mechanism of cross polarization for the mobile components, the time-resolved polarization of the corresponding 13C-signals is investigated. Further, the spin-lattice relaxation times for the proton magnetization in the rotating frame are studied under direct excitation as well as under cross polarization conditions. Based on the results, we propose a special mechanism of cross polarization which is initiated by a temporary adsorption of mobile molecules to the more rigid capsule surface. During this short period of immobilization, the polarization is transferred from 1H to 13C nuclei. After desorption, the freshly generated 13C-signal is essentially conserved, now being motionally averaged by a high molecular mobility and detectable as a narrow line in the corresponding spectrum. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.480970
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  • 2
    Electronic Resource
    Electronic Resource
    Electrical conduction and electronic structures of novel tetrathionaphthalene derivatives (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 1475-1478 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electrical conduction of pristine (undoped) and iodine doped vacuum deposited films of the novel donors, dibenzodithiotetra-thionaphthalene and dibenzodithiotetraselenonaphthalene were measured. The electronic structures of these donor compounds were examined experimentally by ultraviolet photoelectron spectroscopy and theoretically by semiempirical MO calculations and compared with the corresponding data of tetrathiotetracene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347234
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  • 3
    Electronic Resource
    Electronic Resource
    Proton spin-lattice relaxation dispersion of liquid crystal polymers: Characterization of local and collective motions (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 3794-3802 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: This paper reports on studies of the longitudinal proton spin relaxation dispersion T1Z(ω) of a nematic main chain liquid crystal polymer (M¯n=30 000) over a very broad Larmor frequency range (1 kHz≤ω/2π≤120 MHz). Analysis of the experiments is achieved in terms of a density operator treatment employing the Redfield approximation. The results show that collective motions contribute to the proton spin relaxation process in the kilohertz regime, as found for low molar mass liquid crystals, whereas the conventional megahertz range is dominated by reorientation of individual molecules. The intramolecular motions consist of trans–gauche isomerization and phenyl ring flips. These motions are the fastest in the hierarchy of time with correlation times of 10−10 s in the nematic melt of the polymer at T≈460 K. The intermolecular (whole molecule) motions are interpreted as rotational diffusion in an orienting potential. They exhibit a T1Z(ω)∼ω0.65 dispersion in the megahertz range and have correlation times ranging from 10−9 to 10−7 s at this temperature. The slowest motions affecting longitudinal spin relaxation can be assigned to nematic order director fluctuations characterized by a broad distribution of thermally activated modes. Analysis of the dispersion profiles in the kilohertz regime provides the viscoelastic parameters of the main chain liquid crystal polymer. At T=460 K, an average elastic constant of K=8×10−11 N and an effective viscosity of η=1×103 Pa s have been determined. Using the experimentally accessible value for the short wavelength cutoff of the elastic modes, one obtains the mean-square amplitude of the director fluctuations 〈θ02(approximately-greater-than)=0.02, corresponding to a director order parameter of SOF=0.98. Thus, the contributions of the collective chain motions to the measured order parameters are negligible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.462960
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  • 4
    Electronic Resource
    Electronic Resource
    Topically applied lactic acid increases spontaneous secretion of vascular endothelial growth factor by human reconstructed epidermis (2001)
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 145 (2001), S. 0 
    Details
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Alpha-hydroxy acids (AHAs) are widely used for the treatment of hyperkeratotic skin disorders and photodamaged skin. Objectives To investigate the effect of lactic acid (LA) on the secretion of cytokines by keratinocytes (KCs) of human reconstructed epidermis. Methods Creams containing 1·5%, 3% or 5% LA or vehicle controls were topically applied on to human epidermal equivalents (EEs). After 24 h, EEs were analysed for morphology and for the presence of apoptotic cells. Secretion of vascular endothelial growth factor (VEGF), angiogenin (ANG) and interleukin (IL)-8 was measured in the supernatants by enzyme-linked immunosorbent assay. Results LA led to a concentration-dependent increase in apoptotic cells as determined by cell morphology and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling. VEGF secretion was increased 2·5- and 2·8-fold (P 〈 0·05) over vehicle control after treatment with 1·5% and 3% LA, respectively. No significant increase in VEGF secretion was detected with 5% LA. In contrast to VEGF, secretion of ANG was decreased by LA in a concentration-dependent manner (0·5-fold for 5% LA; P 〈 0·01). No significant changes in IL-8 secretion were found with any of the concentrations tested. Conclusions Our data demonstrate that the topical application of AHAs modulates the secretion of cytokines by KCs. Regulation of KC-derived growth factors and cytokines by AHAs might represent a mechanism contributing to their therapeutic effects in disorders such as photoageing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2133.2001.04274.x
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  • 5
    Electronic Resource
    Electronic Resource
    Polygalacturonase (pectinase), a new oilseed rape allergen (2003)
    Oxford, UK : Munksgaard International Publishers
    Allergy 58 (2003), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Type I hypersensitivity to rapeseed pollen allergens was described as the result of a cross-sensitization with various pollens that could constitute an aggravating factor in birch or grass pollen allergies. Recently, a few rapeseed pollen allergens were described. The aim of the present work was to identify new rapeseed pollen allergens by using two-dimensional gel analysis, microsequencing, and mass spectrometry.Methods:  Water extractable proteins from oilseed rape pollen or stamen were separated by two-dimensional gel electrophoresis. The proteins were then electroblotted onto a nitrocellulose (NC) sheet. The NC sheets were successively incubated with (1) individual human sera pre-selected for their immunoglobulin E (IgE) reactivity to rapeseed pollen proteins, (2) alkaline phosphatase (AP)-conjugated goat anti-human IgE and (3) AP substrate. The allergens localized by this method were then identified by microsequencing andMALDI-TOF mass spectrometry analysis.Results:  Of the 18 sera studied, five recognized a wide multispot zone with a molecular mass around 43 kD and pIs between 6.5 and 8.5. The results obtained with two representative sera are shown. From this zone, two isoforms of the polygalacturonase enzyme were identified by microsequencing. Confirmation was obtained through MALDI-TOF mass spectrometry analysis.Conclusion:  The present results allow the identification of a new rapeseed allergen that can be the main allergen for some patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1398-9995.2003.00094.x
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  • 6
    Electronic Resource
    Electronic Resource
    The State of the Field in UK Management Research: Reflections of the Research Assessment Exercise (RAE) Panel (2003)
    Oxford, UK and Boston, USA : Blackwell Publishing Ltd
    British journal of management 14 (2003), S. 0 
    Details
    ISSN: 1467-8551
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This paper reviews the state of the field of the sub-disciplines within UK management research, based upon the submissions of 94 UK higher education institutions to the Business and Management Studies Panel in the UK's 2001 Research Assessment Exercise (RAE). It offers observations on the UK model of the assessment of quality in, and funding of, research conducted in publicly funded higher education institutions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/1467-8551.00265
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  • 7
    Electronic Resource
    Electronic Resource
    Deuteron nuclear magnetic resonance study of the dynamic organization of phospholipid/cholesterol bilayer membranes: molecular properties and viscoelastic behavior (1992)
    s.l. : American Chemical Society
    Biochemistry 31 (1992), S. 1100-1112 
    Details
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bi00119a019
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  • 8
    Electronic Resource
    Electronic Resource
    Photochemistry of 5,6-heptadien-2-one (1969)
    s.l. : American Chemical Society
    The @journal of organic chemistry 34 (1969), S. 2814-2817 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo01262a003
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  • 9
    Electronic Resource
    Electronic Resource
    Voltammetric study of the underpotential deposition of copper on polycrystalline and single crystal palladium surfaces
    Amsterdam : Elsevier
    Electrochimica Acta 33 (1988), S. 341-345 
    Details
    ISSN: 0013-4686
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0013-4686(88)85026-6
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  • 10
    Electronic Resource
    Electronic Resource
    Structural investigation of the initial stages of copper electrodeposition on polycrystalline and single crystal palladium electrodes
    Amsterdam : Elsevier
    Electrochimica Acta 35 (1990), S. 1189-1194 
    Details
    ISSN: 0013-4686
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0013-4686(90)80038-P
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