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  • 1
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We present the design and calibration of a scanning force microscope which can be used to study friction, adhesion, and contact potential differences between the cantilever tip and surface. The microscope uses a modular design where the laser, cantilever/sample holder, reflecting mirror, and detector are mounted directly on an optical table. The laser, reflecting mirror, and detector are mounted on translation and rotation stages. With this design the components can be rearranged to calibrate the Z piezo motion as a function of applied voltage. Using the detector micrometers, the detector response (voltage-to-distance relationship) can be determined after each series of measurements. The cantilever/sample holder is constructed such that the components are material matched and thermally compensated from a common reference point. This design feature minimizes thermal drift of the instrument. The instrument can be used in a contact scanning mode where both normal and lateral deflections of the cantilever are measured. In addition, the instrument can be used in frictional force studies, force curve mapping of the surface, and contact potential measurements. We present examples of each, including a detailed account of the instrument design and calibration. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 2449-2451 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The friction behavior of a diamond-like carbon coating was studied in reciprocating sliding contact at speeds from 0.01 to 5 mm/s, in dry nitrogen. "Superlow" friction coefficients of 0.003–0.008 were obtained in continuous sliding at the higher speeds (〉1 mm/s). However, friction coefficients rose to values typical of diamond-like carbon in dry and ambient air (0.01–0.1) at lower speeds (〈0.5 mm/s) as well as in time-delayed, higher speed tests. The rise of the friction coefficients in both speed and time-delay tests was in good quantitative agreement with gas adsorption kinetics predicted by the Elovich equation for adsorption onto carbon. More generally, superlow friction could be sustained, suppressed, and recovered as a function of exposure time, demonstrating that duty cycle cannot be ignored when predicting performance of superlow friction coatings in devices. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of natural products 44 (1981), S. 190-192 
    ISSN: 1520-6025
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 115 (1993), S. 5869-5870 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 114 (1992), S. 5897-5898 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 115 (1993), S. 803-804 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The cytokine profile of CD4+, CD8+ T cells, γδ+ T cells and natural killer (NK) cells (CD94+CD3–) was studied in a patient with visceral leishmaniasis (VL). The otherwise healthy, human immunodeficiency virus-negative patient acquired the disease in Tuscany, Italy. Diagnosis was made by demonstration of high concentrations of antibodies against Leishmania antigens in serum. Flow cytometry for the detection of intracellular interferon-γ (IFN-γ), interleukin (IL)-2, IL-4, IL-6, IL-10, IL-13 and tumour necrosis factor (TNF)-α expression in peripheral blood mononuclear cells stimulated with phorbol 12-myristate 13-acetate and ionomycin was performed, followed by treatment with liposomal amphotericin B. CD4+ cells were identified as major cytokine-expressing cells, capable of producing both type 1 and type 2 cytokines. A high frequency of IL-4- and IL-13-expressing CD8+ cells was noted. NK cells and γδ+ T cells, thought to be involved in innate host defences against Leishmania, expressed IFN-γ and TNF-α. Ten per cent of γδ+ T cells expressed IL-10, predominantly together with IFN-γ, suggesting additional immune-regulatory roles for this T-cell subset in VL.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0021-9673
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 41 (1986), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In analogy with findings from animal experiments, people with low glutathione-peroxidase (GSH-Px) activity could be expected to have altered sensitivities to effects of drugs, chemicals and possibly food. We have investigated GSH-Px activity in 12 patients with intrinsic asthma and food and aspirin intolerance. Ten of the 12 patients had very low or low GSH-Px activity and the frequency of low GSH-Px activity in this group was statistically significant (P 〈 0.001) compared with the control material of age- and sex-matched healthy individuals. Our finding of lowered GSH-Px activity in patients with aspirin intolerance may indicate the involvement of hitherto unknown mechanisms in the pathogenesis of asthmatic disorders.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-1440
    Keywords: Intraperitoneal insulininjection ; Bolus injection ; Pharmakokinetics of insulin ; Intraperitoneale Insulingabe ; Bolusinjektion ; Pharmakokinetik von Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Obgleich bei der Insulinbehandlung des insulinpflichtigen Diabetikers Kohlenhydratmahlzeiten und subcutane Insulingaben aufeinander abgestimmt werden, besteht oft ein Mißverhältnis zwischen dem augenblicklichen Insulinbedarf und dem aktuellen Insulinangebot, da Insulin relativ langsam aus dem subcutanen Injektionsdepot resorbiert wird. Während die Plasmainsulinkonzentration beim Gesunden nach einer kohlenhydratreichen Mahlzeit nach ca. 45 Minuten ihr Maximum erreicht, wird nach subcutaner Gabe von Normalinsulin das Maximum des Insulinspiegels erst nach ca. 2 Stunden beobachtet. Deswegen wurde untersucht, ob mit intraperitonealerBolusgabe von Insulin ein rascherer Insulinspiegelanstieg zu erreichen ist. 5 stoffwechselgesunden freiwilligen Probanden wurde 20 Einheiten Normalinsulin in isotoner Kochsalzlösung verdünnt intraperitoneal injiziert. Anschließend wurde das Verhalten der Insulinkonzentration im peripher-venösen Blut gemessen. Zur Vermeidung von Hypoglykämien waren die Versuchspersonen an einen „Biostator“ (sogenannte künstliche Betazelle) angeschlossen, der automatisch bei Unterschreiten einer Blutzuckerkonzentration von 60 mg/dl bedarfsgerecht Glukose infundiert und derart ein stärkeres Absinken des Blutzukkers verhindert. Bei allen Probanden kam es nach der intraperitonealen Bolusgabe von Insulin innerhalb weniger Minuten zu einem raschen Anstieg der peripher venösen Insulinkonzentration. Nach ca. 20 Minuten wurde das Maximum der Insulinkonzentration erreicht. Nach ca. 2 Stunden waren die Seruminsulinspiegel bereits deutlich abgefallen und näherten sich dem Ausgangswert. Die Insulinkonzentrationsänderungen nach intraperitonealer Bolusgabe von Insulin entsprechen somit weitgehend den Insulinkonzentrationsabläufen, die im peripher-venösen Blut bei stoffwechselgesunden Personen nach einer kohlenhydratreichen Mahlzeit beobachtet werden. Die intraperitoneale Bolusgabe von Insulin stellt daher eine Applikationsmöglichkeit dar, die für die Behandlung insulinpflichtiger Diabetiker weiterverfolgt werden sollte.
    Notes: Summary Although carbohydrate-intake and subcutaneous insulin injection in the insulin dependent diabetics are brought to match with one another, there is often an incongruity between the momentary insulin need and the actual insulin supply, because insulin is resorbed relatively slow from the subcutaneous injection site. While the plasma insulin concentration in healthy persons after carbohydrate-intake reaches its maximum after ca. 45 min, the maximum insulin concentration after subcutaneous application of regular insulin is observed only after ca. 2 h. For this reason, we studied whether a faster rise in the insulin concentration can be obtained by intraperitonealbolus application of insulin. 5 metabolic healthy volunteers received 20 UI regular insulin diluted in isotonic saline solution injected intraperitoneal. The insulin concentration in the peripherovenous system was examined. In order to prevent severe hypoglycaemia the test persons were connected to a Biostator (so-called artificial Beta-cell), which delivered glucose automatically when the blood glucose concentration fell below the 60 mg/dl — level, and thus avoided a drastic fall of the blood glucose. A rapid increase in the plasma insulin concentration was observed within a few minutes after the intraperitoneal bolus injection of insulin. After ca. 20 min the maximal insulin concentration was reached. Already after ca. 2 h the plasma insulin levels fell off and approached the initial values. Consequently, the changes of insulin concentration after intraperitoneal bolus application of insulin correspond widely to the insulin curve characteristic of metabolic healthy persons after carbohydrate-intake. Thus, the intraperitoneal bolus injection of insulin presents a mode of application, which must be pursued further in the treatment of insulin dependent diabetics.
    Type of Medium: Electronic Resource
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