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  • 1
    Electronic Resource
    Electronic Resource
    A multiple pin, flip-chip system for microwave and gigabit per second cryogenic device testing at variable temperatures (2001)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 1542-1547 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We have developed a cryogenic probe and cryostat system to test both active and passive superconducting devices and circuits up to microwave frequencies at variable temperatures. Our system consists of two basic parts: the cryostat and the matching probe. The cryostat is a unique, very efficient, variable temperature, flow-type cryostat, where we control temperature without electrical heaters. It is magnetically shielded and allows rapid testing between 4.2 K and room temperature. Probes developed for this cryostat have a larger number of shorter cables than standard dip-type probes. They are designed to test chips or chip assemblies without additional packaging. Chips or chip assemblies can be quickly mounted and dismounted from a fixed spring-contact assembly. Each probe has 56 wide-bandwidth signal cables. We have repeatedly used these probes for testing both active and passive superconducting integrated circuits up to 20 GHz. The probe and cryostat combination provides a testing capability that is simultaneously high frequency, dc magnetic shielded, has variable cryogenic temperature, and quick turnaround. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1337072
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  • 2
    Electronic Resource
    Electronic Resource
    Antioxidant and anti-inflammatory activities of melanocortin peptides (2004)
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc
    Experimental dermatology 13 (2004), S. 0 
    Details
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: α-Melanocyte-stimulating hormone (α-MSH) has previously been identified as a potent anti-inflammatory agent in various tissues including the skin. It operates by binding to the melanocortin-1 receptor (MC-1R) which results in the elevation of cyclic AMP. α-MSH opposes the action of several proinflammatory cytokines including tumour necrosis factor-α (TNF-α). We have shown that α-MSH can inhibit TNF-α-stimulated activation of nuclear factor-κB (NF-κB) in human cultured melanocytes, melanoma cells, keratinocytes, fibroblasts, Schwann cells and olfactory ensheathing cells. It also inhibits TNF-α-stimulated upregulation of intercellular adhesion molecule-1 (ICAM-1) in many of these cells and can inhibit peroxide-stimulated activation of glutathione peroxidase, suggesting an antioxidant role. α-MSH is also able to stimulate intracellular calcium release in keratinocytes and fibroblasts (which do not readily show detectible cyclic AMP elevation) but only in the presence of PIA (an adenosine agonist). The carboxyl terminal tripeptides KPV/KP-D-V are reported to be the minimal sequences necessary to convey anti-inflammatory potential, but evidence on how they act is not fully known. Stable transfection of Chinese hamster ovary cells with MC-1R suggests that the KPV peptides operate by this receptor, at least by elevating intracellular calcium. Elevation of cyclic AMP by these tripeptides has not been detected in any cell type studied; however, calcium elevation can inhibit TNF-α-stimulated NF-κB activity (as for cyclic AMP). In conclusion, the MSH peptides convey anti-inflammatory and antioxidant activity in many cell types in skin and nerve, by counteracting proinflammatory cytokine signalling. The KPV peptides appear to act functionally via the MC-1R and can also elevate intracellular calcium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.0906-6705.2004.0212ak.x
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  • 3
    Electronic Resource
    Electronic Resource
    Characterization of an in vitro model of human melanoma invasion based on reconstructed human skin (2000)
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 142 (2000), S. 0 
    Details
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The purpose of this study was to compare the invasive properties of normal human cutaneous melanocytes and of a cutaneous melanoma cell line (HBL) in a three-dimensional model of reconstructed human skin. Specifically, we asked to what extent the pigmentary and invasive behaviour of both cells is influenced by their interaction with adjacent skin cells (keratinocytes and fibroblasts) and the basement membrane (BM). In the presence of a BM, normal human melanocytes within this model remained within the basal layer of keratinocytes and did not pigment spontaneously. When the BM was removed, melanocytes were found suprabasally and pigmented extensively. No significant invasion of melanocytes into the dermis was detected in the presence or absence of the BM. HBL melanoma cells showed no significant ability to invade into the dermis in the absence of other cells, irrespective of the presence or absence of the BM. However, when added to keratinocytes and fibroblasts, HBL cells showed a capacity to invade into the dermis, both in the presence and absence of the BM. Associated with HBL invasion into the dermis, we noted significant keratinocyte entry into the dermis. On their own, keratinocytes entered the dermis in the absence of the BM but showed no significant penetration into the dermis when the BM was present. In summary, this model demonstrates clear differences between melanocytes and a melanoma cell line with respect to their invasive properties. It also allows demonstration of interactions between cells, and between cells and the BM. The study also provides evidence for a synergistic interaction between this melanoma cell line and keratinocytes in penetrating the BM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2133.2000.03287.x
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  • 4
    Electronic Resource
    Electronic Resource
    Back Flow Creep Phenomena in Short Fibre Reinforced Aluminium Alloys (2002)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 396-402 (July 2002), p. 1303-1308 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/06/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.396-402.1303.pdf
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  • 5
    Electronic Resource
    Electronic Resource
    Heck reactions catalyzed by oxide-supported palladium – structure–activity relationships (2000)
    Springer
    Topics in catalysis 13 (2000), S. 319-326 
    Details
    ISSN: 1572-9028
    Keywords: Heck reaction ; formation of carbon–carbon bonds ; oxide-supported palladium ; Pd dispersion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The catalytic activity and selectivity of palladium supported on various metal oxides in carbon–carbon coupling reactions of aryl bromides with styrene (Heck reaction) were investigated. The activity is determined by the nature of the oxide support and the Pd dispersion (structure–activity relationships). The relation of homogeneous (leaching) and heterogeneous mechanisms is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009022030636
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  • 6
    Electronic Resource
    Electronic Resource
    A new quantitative test method for cell proliferation based on detection of the Ki-67 protein (2000)
    Springer
    Journal of materials science 11 (2000), S. 125-132 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract A quantitative method to assess cell proliferation is one essential prerequisite for testing biomaterial cytocompatibility in vitro. Currently used methods, e.g. bromodeoxyuridine incorporation, show serious disadvantages concerning either sensitivity, specificity or handling. A new enzyme linked immunosorbent assay (ELISA) system for the quantification of cell proliferation based on detection of the Ki-67 protein is described. This protein has turned out to be strictly correlated with the active parts of the cell cycle but to be absent in G0. The measurement of Ki-67 expression by different human cell types, e.g. endothelial cells and HeLa cells, was evaluated in order to answer the question of whether the data obtained using the Ki-67 ELISA method correlate with the proliferation measured with flow cytometrical DNA analysis and microscopical evaluation. Methods currently used for the evaluation of cell proliferation were compared to the new Ki-67 ELISA method. In addition, the functionality of adherent endothelial cells, and the viability and morphology of the cells were investigated. Cells were treated with standard culture medium with or without the transcription inhibitor, actinomycin D, or growth factors, e.g. endothelial cell growth factor (ECGF), and were exposed to metal ion standard solutions. These solutions were in a cytotoxic–non-cytotoxic range. Ki-67 ELISA was found to be a reliable quantitative method to assess proliferation of cultured human cells in vitro. It has advantages over methods that are currently being used. It is easy to perform and corresponds to the requirements for a test to be selected for biomaterial testing according to ISO standard 10 993.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008953319485
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  • 7
    Electronic Resource
    Electronic Resource
    Cone prosthesis for the hip joint (2000)
    Springer
    Archives of orthopaedic and trauma surgery 120 (2000), S. 88-95 
    Details
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The shape of the proximal segment of the femur must be taken into account when implanting femoral endoprostheses, especially those intended for cementless anchorage. Numerous femoral prostheses are available for the proximally broadly extending, “trumpet-shaped” morphology. However, the femur often has a narrow, more cylindrical configuration, as is frequently seen with dysplastic hip joints, but variants of the anatomical constitution or ethnic variants are also found. Conventional femoral prostheses with a proximal transverse oval or rectangular cross-section are often incorrectly positioned in those cases because they can fracture the narrow bones. In many instances, even a pathological anteversion attachment cannot be adequately corrected. The cone prosthesis is ideal for this morphology when pre-operative planning indicates good contact between the bone cortex and the middle third of the prosthetic stem. The tapered anchorage of the cone stem in the medullary cavity reamed to a cone shape promotes primary stability, which is a fundamental prerequisite for the osseointegration of a coarse blasted titanium implant. The sharp longitudinal ridges on the prosthetic stem, which tend to cut into the bone, ensure extensive rotational stability, which explains why thigh pain is not associated with the cone prosthesis. The cone prosthesis has proved its worth in 635 implants performed over 9 years, with highly satisfactory clinical and X-ray results. The surgical technique is relatively straightforward, and complications are rare. The patients’ subjective satisfaction is particularly remarkable. The success of the operation lies in correct preoperative planning, which ensures that the morphology of the selected femur guarantees contact between the bone cortex and the middle third of the prosthetic stem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004020050018
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  • 8
    Electronic Resource
    Electronic Resource
    Differential sustained attention/vigilance changes over time in schizophrenics and controls during a degraded stimulus Continuous Performance Test (2000)
    Springer
    European archives of psychiatry and clinical neuroscience 250 (2000), S. 24-30 
    Details
    ISSN: 1433-8491
    Keywords: Key words Schizophrenia ; Continuous Performance Test ; Decrements of Vigilance ; Sustained Attention ; Neuropsychology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The Continuous Performance Test (CPT) is a widely used procedure for sustained attention/vigilance measurement. However, though the key index of vigilance impairment is the decrement of sensitivity over time during the test period, only few studies have examined whether schizophrenics show a larger drop in CPT performance than do healthy controls. 48 schizophrenic inpatients and 48 controls were investigated with the Munich CPT (480 visual stimuli, 25% target stimuli, one stimulus per second). Stimuli were degraded by randomly inverting 40%, 41%, 42%, or 43% of the pixels. Results were calculated separately for three consecutive trial sections. Additionally, PANSS ratings, medication, and other clinical data were documented. Schizophrenics show a vigilance decrement over time, controls show a vigilance increase. Differential vigilance changes were not related to the level of stimulus degradation. Schizophrenics performed worse than controls only at the lowest degradation level. While overall sensitivity correlated negatively with the dose of atypical neuroleptics and benzodiazepines, vigilance shifts over time correlated negatively with the dose of typical neuroleptics. Furthermore, sensitivity was related to the cognitive PANSS syndrome, number of admissions/duration of illness. Differential sensitivity decrements of schizophrenics and controls can be shown if suited CPT procedures are used. The need for basic research on experimental conditions of the CPT as well as examination of the relationship between sustained attention/vigilance decrements and clinical features of schizophrenia is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00007535
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  • 9
    Electronic Resource
    Electronic Resource
    Eine neue Technik zur Rekonstruktion des vorderen Kreuzbandes unter Verwendung von Hamstring-Sehnen und biodegradierbaren Interferenzschrauben (2000)
    Springer
    Arthroskopie 13 (2000), S. 280-286 
    Details
    ISSN: 1434-3924
    Keywords: Schlüsselwörter Vorderes Kreuzband ; Rekonstruktion ; Semitendinosussehne ; Interferenzschrauben ; Biodegradierbar ; Keywords Anterior cruciate ligament ; Reconstruction ; Hamstring tendons ; Interference screws ; Biodegradable
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: A new technique for hamstring tendon anterior cruciate ligament reconstruction is introduced which facilitates an anatomic graft fixation close to the joint line. An anatomic graft fixation has been shown to increase knee stability and graft isometry. Fixation is performed using biodegradable poly-(D-, L-lactide) interference screws which promotes tendon-to-bone incorporation. Preliminary clinical results at one year demonstrate 95% normal or nearly normal knees according to the criteria of the IKDC. These data suggest that hamstring tendon interference fit fixation combines minimal invasive aspects of the use of hamstring tendons with biomechanical advantages of anatomic interference screw fixation, thus offering a reasonable alternative to the use of the mid third patellar tendon graft.
    Notes: Eine neue Technik zur Rekonstruktion des vorderen Kreuzbandes unter Verwendung des Semitendinosus- und Grazilis-Sehnentransplantats wird vorgestellt, die eine anatomische Transplantatverankerung direkt auf Gelenkniveau ermöglicht. Eine anatomische Transplantatverankerung hat den Vorteil, die Kniestabilität und die Transplantatisometrie zu erhöhen. Biodegradierbare Poly-(D-,L-Laktid-)Interferenzschrauben werden zur Verankerung verwendet, was zu einer beschleunigten ossären Integration des Transplantats führt. Klinische Frühergebnisse nach einem Jahr zeigen 95% normale oder fast normale Kniegelenke nach den Kriterien des IKDC. Die Daten der vorliegenden Studie unterstützen die Annahme, dass die beschriebene Technik den minimal-invasiven Aspekt der Verwendung von Hamstring-Sehnentransplantaten mit den biomechanischen Vorteilen der Interferenzschrauben-Verankerung kombiniert und so eine Alternative zu herkömmlichen Techniken darstellt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001420050175
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  • 10
    Electronic Resource
    Electronic Resource
    Pontryagin Principle for State-Constrained Control Problems Governed by a First-Order PDE System (2000)
    Springer
    Journal of optimization theory and applications 107 (2000), S. 297-330 
    Details
    ISSN: 1573-2878
    Keywords: multidimensional control problems ; state constraints ; Young measure relaxation ; Pontryagin principle ; first-order necessary conditions ; solutions of first Baire class
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract This paper considers multidimensional control problems governed by a first-order PDE system and state constraints. After performing the standard Young measure relaxation, we are able to prove the Pontryagin principle by means of an ∈-maximum principle. Generalizing the common setting of one-dimensional control theory, we model piecewise-continuous weak derivatives as functions of the first Baire class and obtain regular measures as corresponding multipliers. In a number of corollaries, we derive necessary optimality conditions for local minimizers of the state-constrained problem as well as for global and local minimizers of the unconstrained problem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026481403476
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