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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 4 (1990), S. 139-143 
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Analysis of the profiles of isotope clusters can be used to determine the charge state of ions in thermospray mass spectrometry. This observation was verified by comparison of experimental results with theoretical calculations. The applicability of this technique was illustrated by the characterization of peptides whose molecular weights were in the range of 500 to 5000 Da. Using thermospray ionization on a quadrupole mass spectrometer, [M + 2H]2+ and [M + 3H]3+ ions of the peptides were identified. These multiply charged ions enabled us to characterize molecules with molecular weights exceeding the normal mass range of the instrument.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 30 (1995), S. 1505-1511 
    ISSN: 1076-5174
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Δ8,9-Dehydroestrone is the fifth most abundant component in the conjugated equine estrogen preparation Premarin®, representing about 2 to 6% of the total steroids in the tablet. The metabolism of this estrogen has been determined in female beagle dogs after acute peroral administration. 17β-Dihydro-Δ8,9-dehydroestrone(17β-Δ8,9-dehydroestradiol) and 17α-dihydro-Δ8,9dehydroestrone(17α-Δ8,9-dehydroestradiol) have been identified as the major metabolites in plasma and urine. These metabolites, along with the unchanged drug, were isolated and purified by ether extraction and thin-layer chromatography of the urine samples after enzyme hydrolysis. The trimethylsilyl ether derivatives of the isolated metabolites were characterized by comparison of their mass spectra and chromatographic properties with those of synthetic reference standards.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 12 (1978), S. 541-555 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The corrosion of carved, burnished, polished, and burnished-polished samples of a conventional spherical amalgam was studied by anodic polarization in Ringer's solution. The effect of the variation of the mercury content from 40 to 60 wt% on the corrosion of burnished or polished samples was also investigated. It was found that burnished and burnished-polished samples corrode the least and carved samples the most. The current-density peak associated with γ2 was of greater magnitude in polished specimens than in burnished specimens throughout the range of mercury concentrations investigated. It is hypothesized that lower porosity and more ready passivation of the surface due to a high amount of γ2 are the reasons that burnished samples corroded less than polished samples in this anodic polarization test.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 23 (1989), S. 819-831 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: This study was conducted to investigate some fundamental fatigue testing variables as they apply to the response characteristics of acrylic bone cement. Cyclic loading under load control was conducted at frequencies of 1, 2, 5, 10, and 20 Hz in air at room temperature. At a tensile stress range of 0.3-20.0 MPa the fatigue life increased linearly with logarithmic frequency. The effect of conditioning and testing in saline at both room temperature and 37°C at similar stress levels and a frequency of 10 Hz were also examined. When compared to dry testing at room temperature, testing in saline at 37°C resulted in a reduction in fatigue life while testing in saline at room temperature produced an increase in fatigue life. Of a number of statistical distributions considered, the Weibull was found to be the most appropriate in documenting the findings of this investigation. A companion fractographic investigation of the failure surfaces demonstrated distinct regions of crack growth and fast fracture.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Electrophoresis 12 (1991), S. 402-408 
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Gangliosides are sialic acid-containing glycosphingolipids. In aqueous media, these glycolipids have been shown to exist as stable micelles. Ganglioside micelles could be analyzed by high-performance zonal capillary electrophoresis in uncoated fused-silica capillaries within 10 min. The mass sensitivity determined by monitoring the absorption of ultraviolet light at 195 nm was in the order of 10-11 mol. Increasing the pH of the running buffer from 3.0 to 7.4 or the voltage from 10 to 30 kV increased the relative mobilities of gangliosides. By contrast, increasing the ionic strength of the buffer decreased the migration and broadened the elution peak widths of gangliosides. GangliosideThe abbreviations used for gangliosides are according to the recommendations of the Nomenclature Committee, International Union of Pure and Applied Chemistry [46]. The basic designation of ganglio-series gangliosides are based on the Svennerholm system [47]. For example: GMl, II3NeuAc-GgOse4Cer. micelles including GM1, GD1b and GT1b were resolved into separate peaks by capillary electrophoresis at physiological pH shortly after mixing. Upon prolonged inc ubation, the ganglioside peaks merged to form a single species. The fusion process was temperature-dependent. At 50°C, formation of mixed micelles between polysialogangliosides GD1b and GT1b was complete within 30 min. In contrast, no fusion of the ganglioside peaks was observed at 0°C even after 75h. Formation of mixed micelles between GD1b and other polysialogangliosides including GD1a, GT1b and GQ1b at 37°C required 1.5, 3.0 and 2.0 h, respectively. Formation of mixed micelles between monosialoganglioside GM1 and polysialogangliosides were 6- to 36-fold slower. No fusion was observed between monosialogangliosides GM1 and GM2 after 2 days of incubation. These findings indicate that polysialogangliosides may have higher propensities than monosialoganglioside to form mixed micelles.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 16 (1981), S. 374-375 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 58 (1962), S. 545-552 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dilatometric data for the glass transition temperature Tg of poly(4-methyl-1-pentene) (PMP) have been extended to more crystalline samples and rendered more precise. Tg is definitely shown to decrease with increasing degree of crystallinity, an effect which tentatively is related to increasing free volume of the amorphous part of the polymer as the less dense crystalline phase increases and pulls apart the polymer chains in the amorphous regions. Tg is determined to be 14 ± 2°C. for 78% crystalline PMP, and 25 ± 2°C., for amorphous polymer. The existence of a higher-order transition at 125 ± 10°C. is confirmed by x-ray measurements and ascribed to transverse chain segment motion.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 61 (1962), S. S29 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 18 (1980), S. 607-612 
    ISSN: 0360-6384
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salze einer isomeren Form des Chloro-n-butylamin-, Chloro-iso-butylamin- und Chloro-sec-butylamin-bis(ätylendiamin)-kobalt(III)-Kations wurden dargestellt und spektroskopisch als Komplexe mit cis-Konfiguration charakterisiert. Die Geschwindigkeitskonstanten des spontanen bzw. durch HgII induzierten Ligandenaustausches mit H2O und des hydrolytischen OH-Eintausches wurden bestimmt und die Aktivierungsparameter berechnet. Die Ergebnisse werden mit den an den n-Propylaminkomplexen erhaltenen verglichen, besonders in Hinsicht auf den Einfluß der (α, β, γ) Methylgruppen auf die Reaktivitäten. Die geschwindigkeitsbestimmende Abdissoziation von Cl-oder HgCl+ verläuft entweder über einen quadratisch-pyramidalen oder einen trigonal-bi-pyramidalen Zwischenzustand, je nachdem, ob die Aktivierungsentropie negativ oder positiv ist.
    Notes: Salts of one isomeric form of the chloro-n-butylamine-, chloro-iso-butyl-amine- and chloro-sec-butylamine-bis(ethylenediamine)cobalt(III) cations have been prepared and characterised to have a cis-configuration (IR and VIS spectroscopy). Rate constants for their spontaneous aquation, mercury(II)-induced aquation and base hydrolysis have been determined and the activation parameters calculated. The results are compared with data obtained for the n-propylamine complex with a view to investigate the effects of methyl (α, β, γ) substituents on reactivities.The rate-determining dissociation of the outgoing group (Cl- or HgCl+) takes place via either a square-pyramidal or a trigonal-bipyramidal intermediate, depending on whether the activation entropy is negative or positive.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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