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  • 1
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 2213-2224 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Guided ion-beam techniques are used to measure the cross sections for reaction of SiF4 with Ar+, Ne+, and He+ from thermal to 50 eV. Charge transfer followed by loss of F atoms are the sole processes observed. All SiF+x (x=0–4) products are observed, except for SiF+4 from reaction with Ne+ and He+, and Si+ from reaction with Ar+. At high energies, the dominant products are SiF+3 in the Ar system, and SiF+ in both the Ne and He systems. There is some evidence in the Ne system for an excited state of SiF+3 at 5.7 eV. In the Ar+ and Ne+ reactions, the observed energetics are consistent with literature thermochemistry, but with He+, reaction barriers are observed. A value of ΔH0f,298 (SiF+3)=−30.1±0.9 kcal/mol is derived, which is in agreement with previous values but is much more precise. The observed product distributions and energetics are explained by consideration of the potential energy surfaces and the difference in ionization potentials of the rare gases. Finally, the relationships of these reactions to plasma deposition and etching are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 63 (1988), S. 3118-3118 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Materials exhibiting strong Faraday rotation are of interest for components in laser systems. These include optical isolators, circulars, modulators, and switches in sizes ranging from microdevices for integrated optics to 30-cm-diam rotators for Nd:glass lasers used in inertial confinement fusion research. Properties of diamagnetic, paramagnetic, ferromagnetic, dilute magnetic semiconductors and free carrier rotators have been evaluated for various laser applications and for operation in the spectral range from the infrared to the ultraviolet and at various temperatures. Both crystalline and amorphous materials are considered; forms include bulk materials, fibers, and thin films. The characteristics of selected materials, including bismuth-substituted rare-earth iron garnets, Cd1−xMnxTe, and rare-earth doped glasses and crystals, are discussed. Relative figures of merit based on specific rotation, losses, cost, and special properties such as the nonlinear refractive index are also given.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 93 (1989), S. 1596-1604 
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 6898-6910 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The title reaction is studied using guided ion beam mass spectrometry. Absolute reaction cross sections are measured as a function of kinetic energy from thermal to 40 eV, and three endothermic product channels are observed. The dominant SiF++SiF3 channel is only slightly endothermic, while the SiF+3 +SiF and SiF+2 +SiF2 channels have much higher thresholds. The SiF+3 cross section magnitude is about half that of SiF+, while the SiF+2 cross section is an order of magnitude smaller than that of SiF+. A second feature which appears in the SiF+2 cross section is due to dissociation of SiF+3 . There is evidence that SiF+ and SiF+3 are produced via a direct mechanism. Competition between these two channels is interpreted in terms of molecular orbital correlations and qualitative potential energy surfaces. One surface is found to correlate only with the SiF+3 +SiF channel, while another correlates diabatically with this channel and adiabatically with the SiF++SiF3 channel. Competition on this latter surface has an energy dependence which is consistent with the Landau–Zener model. Reaction thresholds are analyzed to yield 298 K heats of formation for SiFx and SiF+x species. From an evaluation of these and literature values, we recommend the following values: ΔH0f(SiF+) =170.4±2.2 kcal/mol, IP(SiF)=7.54±0.16 eV, ΔH0f (SiF3)=−258±3 kcal/mol, and IP(SiF3)=9.99±0.24 eV.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 84 (1986), S. 1521-1529 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The endothermic reaction of Al+ with O2 is studied using a guided ion-beam apparatus. The reaction cross section is measured as a function of kinetic energy from 0 to 20 eV. The threshold energy for the reaction, E0, is determined from an empirical model to be 3.64±0.04 eV. Phase space calculations of the cross section performed with E0 as the only adjustable parameter yield a similar result, E0=3.60±0.02 eV, and predict the absolute magnitude of the reaction cross section within experimental error. We conservatively quote the threshold energy as 3.62±0.12 eV which is somewhat higher than the thermodynamic threshold calculated using literature thermochemistry, 3.40±0.16 eV. This may indicate that a slight barrier to the reaction exists, or that AlO+ is produced in an excited state, or that the literature thermochemistry needs revision. Our results suggest D00 (AlO+)≥1.50±0.12 eV and I.P.(AlO)≤9.75±0.13 eV.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Annals of operations research 16 (1988), S. 149-160 
    ISSN: 1572-9338
    Schlagwort(e): Utility theory ; utility function assessment ; bias ; incomplete information
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Notizen: Abstract The procedure UFAP is presented which allows a decision maker to interactively assess his von Neumann/Morgenstern single attribute utility function. UFAP puts special emphasis on potential biases in the assessment process. In the first part of the procedure three different assessment methods are used to derive ranges for the utility function. Using different methods enables us to point out a possible bias in the elicitation process. In the second part a consistent class of utility functions is derived based on the ranges assessed in the first part. In case inconsistencies between methods arise the decision maker has to reconsider selected preference statements previously given.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 66 (1988), S. 892-898 
    ISSN: 1432-1440
    Schlagwort(e): Diabetic nephropathy ; Urine analysis ; Albumin ; Single proteins ; α-1-microglobulin ; SDS-PAGE ; Diabetische Nephropathie ; Harnanalyse ; Albumin ; Einzelproteine ; α-1-Mikroglobulin ; SDS-PAGE
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Zahlreiche Untersuchungen haben in den vergangenen 10 Jahren belegt, daß die Quantifizierung von Albumin im Urin zur frühzeitigen Diagnose der diabetischen Nephropathie geeignet ist. Dabei wurde die Albuminbestimmung aufgrund ihrer hohen Treffsicherheit bei geringem methodischen Aufwand in den Vordergrund gehoben. Die parallele Untersuchung des Harnproteinspektrums mittels SDS-Polyacrylamidgelektrophorese zeigt jedoch, daß auch andere hoch- und niedermolekulare Proteine in den verschiedenen Stadien der diabetischen Nephropathie vermehrt ausgeschieden werden, so daß eine Erweiterung der reinen Albuminbestimmung um je ein makromolekulares (z.B. Transferrin) und ein mikromolekulares (z.B. α-1-Mikroglobulin) Protein sinnvoll erscheint. Nach der vorliegenden Untersuchung können beide Verfahren (kombinierte quantitative bzw. qualitative Analyse) in der Frühdiagnostik und der Verlaufskontrolle der diabetischen Nephropathie eingesetzt werden.
    Notizen: Summary During the last ten years, several studies proved the applicability of urinary albumin quantification in the early diagnosis of diabetic nephropathy. Owing to its high accuracy and its comparable low methodological effort, only the albumin determination was emphasised. Parallel studies of urinary protein patterns, however, using sodium dodecylsulfate-polyacrylamidegel-electrophoresis demonstrated the increased excretion of other high- and low-molecular mass proteins in different stages of diabetic nephropathy. Consequently an extension of the mere albumin assay including a macromolecular (e.g., transferrin) and a micromolecular (e.g. α-1-microglobulin) protein seems meaningful. According to this study, both methodological lines (combined quantitative and qualitative analysis, respectively) are useful tools in the early detection and the follow up of diabetic nephropathy.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 66 (1988), S. 1196-1196 
    ISSN: 1432-1440
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 67 (1989), S. 707-712 
    ISSN: 1432-1440
    Schlagwort(e): Ketoconazole ; Androgens ; Inhibition of adrenal androgen secretion ; Hirsutism ; Hyperandrogenism therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effect of ketoconazole on adrenal androgen secretion was examined in 15 patients with elevated serum androgens. In a dose of 600 mg per day orally ketoconazole inhibited the biosynthesis of all measured androgens. The mean reduction in serum levels of dehydroepiandrosterone sulfate was 32%, of dehydroepiandrosterone 54%, of androstenedione 52%, and of testosterone 43%; mean serum levels of cortisol only fell by 19%. The reduction in serum androgen levels was first significant 24 h after beginning of treatment and persisted as long as the drug was administered. We conclude that ketoconazole inhibits adrenal androgen biosynthesis more pronouncedly than cortisol biosynthesis. This might be of clinical benefit in the treatment of hirsutism and other states of androgen hypersecretion.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 67 (1989), S. 907-918 
    ISSN: 1432-1440
    Schlagwort(e): Kidney transplantation ; Cyclosporin ; Azathioprine ; Lipoproteins ; Carbohydrate metabolism ; Hormones
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Various endocrine and metabolic disturbances associated with long standing uremia persist after kidney transplantation or arise from the use of immunosuppressive drugs. Hyperlipidemia for long time being implicated as the cause of corticosteroids is also observed in renal transplant recipients treated with cyclosporin A monotherapy. After conversion from cyclosporin to azathioprine serum cholesterol and triglyceride concentration fall, and elevation of LDL-cholesterol may also be reversed. There is a tendency for higher HDL-cholesterol in azathioprine and prednisolone treated transplant patients. Those patients who are at risk for clinically significant cholesterol elevations can be predicted by their pretransplant lipid levels, specifically the LDL-fraction. Risk-benefit ratio of conversion and of treatment with lipid-lowering drugs, especially with lovastatin, should be carefully examined, also in view of glucose intolerance. Higher incidence of diabetes mellitus requiring insulin therapy in cyclosporin treated transplant recipients has been reported. Cyclosporin may cause toxic effects on pancreatic beta-cells resulting in inhibition of insulin secretion. High doses of cyclosporin induce inhibition of glycogen synthesis in rat liver. Glucose intolerance is reversible after reduction of cyclosporin dose or conversion to azathioprine. Therefore glucose metabolism in kidney transplant recipients treated with cyclosporin should be carefully followed. Immunosuppressive therapy may affect reproductive function, arachidonate metabolism and renin-angiotensin-aldosterone system as well as posttransplant calcium and phophate metabolism. Endocrine and metabolic abnormalities are associated with long standing uremia. After successful kidney transplantation several observations are normalized but further complications arise from the use of immunosuppressive drugs. The present paper reviews various endocrine and metabolic disturbances described following renal transplantation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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