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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 1475-1478 
    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
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  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 3794-3802 
    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
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 34 (1969), S. 2814-2817 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    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
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  • 5
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 4242-4250 
    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
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc
    Experimental dermatology 13 (2004), S. 0 
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Bearing the sensory nerve end organ, the skin establishes contact to our environment. So far, the analysis of the cutaneous nervous system was dependent on the use of tissue serial sections. Because such samples inherently allow visualization of only a small part of the mainly horizontally oriented nervous system of the skin, we searched for possibilities enabling a more comprehensive view. Here, we present a method based on the immunostaining of dermal sheet preparations for subsequent analysis by electron microscopy and light, or laser scanning microscopy. We used antibodies against PgP9.5 and NCAM/CD56, both showing a regular network of fibers covering the entire superficial dermis. The bulk of free ending nerve fibers ramified within 25 µm of the dermo–epidermal junction, whereas below that only larger nerve bundles were present. Along the course of nerve fibers, we observed NCAM/CD56+ protrusions with diameters ranging from 5 to 15 µm. We further characterized these protrusions demonstrating the ultrastructural features of terminal non-myelinating Schwann cells ensheathing nerve fibres. Depending on the body region, we detected between 140 and over 300 individual terminal Schwann cells/mm2 skin surface. In a double staining for NCAM/CD56 and vWF, we analyzed the topographical relationship of the nerve end organ to the blood vessels of the skin. In conclusion, this novel method allows for the first time a complex three-dimensional depiction of the cutaneous nervous system over several cm2. Additionally, terminal Schwann cells can be studied in detail in situ for the first time. Furthermore, application of this method may provide new impetus in the investigation of the cutaneous nerve end organ under physiological and pathological conditions.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Copenhagen : Blackwell Publishing Ltd
    Allergy 54 (1999), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Latex allergy is now known to be related to type I hypersensitivity. In latex products, several reports have identified at least 10 allergens. However, 56 polypeptides have been shown to react to IgE by two-dimensional gel electrophoresis and immunoprints. All studies using immunoprints have analyzed a relatively small number of sera. The aim of the present study was to analyze the specificity and the isotypic expression of a wide sample of latex-sensitive patients. Latex proteins were separated by SDS–PAGE in an 8–18% gel gradient, transferred onto a nitrocellulose sheet by Western blot, and revealed by serum from latex-sensitive patients. The presence of IgE, IgA, IgG1, IgG2, IgG3, and IgG4 was analyzed for each of the 54 sera. The results showed Hev b 3 to be the most frequently recognized protein, followed by Hev b 1, Hev b 7, and molecules of 94 kDa and 6–8 kDa. The most common isotypic association was IgE-IgG1, frequently with IgA. IgG4 was also present in a little less than half of the IgE-positive sera. IgG3 was also expressed but frequently recognized nonallergenic molecules. IgG2 was present in only two cases. Thus, as several authors have proposed a protective role for IgG in the allergic reaction, it may be of interest to compare these results with the course of the disease.
    Type of Medium: Electronic Resource
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  • 9
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    Cambridge : Periodicals Archive Online (PAO)
    The Modern language review. 46 (1951) 196 
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 145 (2001), S. 0 
    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
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