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41.
R. Kruse und H. A. Rüssel 《Fresenius' Journal of Analytical Chemistry》1977,286(3-4):226-228
Zusammenfassung Zur gas-chromatographischen Bestimmung von Arsen in biologischem Material wird die Probe in einer Teflon-Bombe aufgeschlossen, das Arsen mit Dithiocarbamat extrahiert, oxidiert und mit Methyltrimethylsilylheptafluorbutyramid silyliert. Die gas-chromatographische Bestimmung läßt sich bis zu einem Arsengehalt von 0,1 ppm ausführen. Die Methode wurde radiochemisch überprüft. Der Einsatz eines flammenphotometrischen Detektors gegenüber einem Flammenionisationsdetektor brachte keine Vorteile.Die Arbeiten wurden dankenswerterweise von der Deutschen Forschungsgemeinschaft und vom Fonds der Chemischen Industrie unterstützt. 相似文献
42.
Positron-sensitive detection was used to measure the spatial decay in intensity of twelve transitions in Fe XIII to Fe XVI. A two-meter grazing incidence spectrometer was equipped with a 25 mm microchannel plate coupled to a resistive anode encoder and was positioned to simultaneously record all EUV radiation in the wavelength range from 24.5 to 31 nm. Data for foil-excited Fe ions at 35 MeV was accumulated at each of 37 foil positions until a fixed amount of beam charge had been collected in a Faraday cup. The considerable advantages of this improved beam-foil time-of-flight technique are discussed. 相似文献
43.
Sarcomeres are the basic force generating units of striated muscles and consist of an interdigitating arrangement of actin and myosin filaments. While muscle contraction is usually triggered by neural signals, which eventually set myosin motors into motion, isolated sarcomeres can oscillate spontaneously between a contracted and a relaxed state. We analyze a model for sarcomere dynamics, which is based on a force-dependent detachment rate of myosin from actin. Our numerical bifurcation analysis of the spontaneous sarcomere dynamics reveals notably Hopf bifurcations, canard explosions, and gluing bifurcations. We discuss possible implications for experiments. 相似文献
44.
Zhao S Kruse DE Ferrara KW Dayton PA 《The Journal of the Acoustical Society of America》2006,120(6):EL63-EL69
In ultrasonic molecular imaging, encapsulated micron-sized gas bubbles are tethered to a blood vessel wall by targeting ligands. A challenging problem is to detect the echoes from adherent microbubbles and distinguish them from echoes from nonadherent agents and tissue. Echoes from adherent contrast agents are observed to include a high amplitude at the fundamental frequency, and significantly different spectral shape compared with free agents (p <0.0003). Mechanisms for the observed acoustical difference and potential techniques to utilize these differences for molecular imaging are proposed. 相似文献
45.
Methods are developed to describe catalytic reactions on multi-facetted surfaces in high electric fields in the conditions of field emission microscopy. These methods are applied to the hydrogen–oxygen–rhodium system for which a mean-field kinetic model is established. This model is shown to reproduce not only the nonequilibrium regimes of bistability and oscillations and their nanopatterns, but also the temperature-programmed desorption spectra of hydrogen and oxygen on rhodium, as well as the equilibrium phase diagram of oxygen on rhodium with the transition to the trilayer surface oxide ORhO. The dependence of the kinetic constants on the surface orientation of the facets is taken into account by expanding them in kubic harmonics suitable for the fcc rhodium crystal. The electric field modifies the gas pressure as well as the activation energies of the different kinetic processes. The tip of the field emission microscope is shown to behave as a nanoreactor. 相似文献
46.
Flörsheimer M Kruse K Polly R Abdelmonem A Schimmelpfennig B Klenze R Fanghänel T 《Langmuir : the ACS journal of surfaces and colloids》2008,24(23):13434-13439
By employing the nonlinear optical, interface selective experiment of sum frequency spectroscopy together with independent ab initio and density functional theory calculations, we determine the functional species of a corundum (001) surface: doubly coordinated OH groups which differ in their bond tilt angles. The interaction of the functional species with the adjacent water molecules is also observed. In a large pH range around the point of zero charge, the interaction is not controlled electrostatically but by hydrogen bonding. The functional species' tilt angles are crucial parameters, determining whether the species act as hydrogen bond donors or acceptors. 相似文献
47.
The reaction of C2 radicals with NO was studied behind reflected shock waves in the temperature range 3150 K≤T≤3950 K. The shock‐induced pyrolysis of acetylene, highly diluted in argon, was used as a well defined source for C2 radicals, which were detected by ring‐dye‐laser absorption spectroscopy (RDLAS) at 516.646 nm. The perturbation of the C2 by the addition of NO to the initial mixtures results in a fast removal of the C2 radicals, which is mainly caused by the reaction: ((R5)) for which the overall rate coefficient was obtained. The product channels of this reaction were studied by additional measurements of O‐atoms, N‐atoms, and CN radicals. O and N were detected using atomic resonance absorption spectroscopy (ARAS) and the CN radicals were followed by their emission using a spectrograph and an intensified CCD‐camera. The reactions leading to the product channels C2N+O (R5a) and to C2O+N (R5b) were identified as the main channels with a branching ratio of k5a/k5=70% and k5b/k5=30%, while the channel leading to CN+CO (R5c) was found to be neglectable. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 11–21, 1999 相似文献
48.
Feenstra RW van den Hoogenband A Stroomer CN van Stuivenberg HH Tulp MT Long SK van der Heyden JA Kruse CG 《Chemical & pharmaceutical bulletin》2006,54(9):1326-1330
The syntheses of several 1-aryl-4-(arylpyridylmethyl)piperazines (4) and their affinities for dopamine D(2) and serotonin 5-HT(1A) receptors are described. The compounds were evaluated both in vitro and in vivo, resulting in the identification of the drug candidate SLV313 (4e) with equipotent and full D(2) receptor antagonism and 5-HT(1A) receptor agonism. Minor structural modifications in SLV313 revealed the possibility of designing compounds possessing varying degrees of partial agonism on one or both target receptors. 相似文献
49.
50.
Lasse Jrgensen Cehofski Anders Kruse Alexander Nrgaard Alsing Benn Falch Sejergaard Jonas Ellegaard Nielsen Anders Schlosser Grith Lykke Sorensen Jakob Grauslund Bent Honor Henrik Vorum 《Molecules (Basel, Switzerland)》2022,27(11)
Aflibercept is a frequently used inhibitor of vascular endothelial growth factor (VEGF) in the treatment of macular edema following central retinal vein occlusion (CRVO). Retinal proteome changes following aflibercept intervention in CRVO remain largely unstudied. Studying proteomic changes of aflibercept intervention may generate a better understanding of mechanisms of action and uncover aspects related to the safety profile. In 10 Danish Landrace pigs, CRVO was induced in both eyes with an argon laser. Right eyes were treated with intravitreal aflibercept while left control eyes received isotonic saline water. Retinal samples were collected 15 days after induced CRVO. Proteomic analysis by tandem mass tag-based mass spectrometry identified a total of 21 proteins that were changed in content following aflibercept intervention. In retinas treated with aflibercept, high levels of aflibercept components were reached, including the VEGF receptor-1 and VEGF receptor-2 domains. Fold changes in the additional proteins ranged between 0.70 and 1.19. Aflibercept intervention resulted in a downregulation of pigment epithelium-derived factor (PEDF) (fold change = 0.84) and endoplasmin (fold change = 0.91). The changes were slight and could thereby not be confirmed with less precise immunohistochemistry and Western blotting. Our data suggest that aflibercept had a narrow mechanism of action in the CRVO model. This may be an important observation in cases when macular edema secondary to CRVO is resistant to aflibercept intervention. 相似文献