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  • 1
    Electronic Resource
    Electronic Resource
    Electron spin resonance studies of plasma-induced polystyrene radicals (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1-7 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma-induced polystyrene radicals were first studied by electron spin resonance (ESR). The room temperature ESR spectrum was compared with those obtained by γ-irradiation, UV-irradiation, and mechanical fracture. It was found that even less than a few seconds of plasma-irradiation gave rise to a large amount of polystyrene radicals and the ESR spectrum consisted of two types of spectra, a triplet and a single broad line. The spectral feature of the triplet was nearly identical with that of γ-irradiated polystyrene. Thus, it was assigned to the structure of a cyclohexadienyl-type radical formed by a nearly random addition of a hydrogen atom to the aromatic ring. The single broad line, thought to be an outline of multicomponent spectrum, was assigned to an immobilized dangling-bond sites at the plasma-induced crosslinked portion of the polystyrene surface.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080290102
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  • 2
    Electronic Resource
    Electronic Resource
    Mechanistic study on mechanochemical polymerization of acrylamide (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 489-494 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ESR study of the radicals formed in mechanochemical polymerization of acrylamide (AAM) was undertaken. The nature of the radical formation was compared with the mechano-radical formation produced by mechanical fracture of polyacrylamide (PAAM). The structure of radicals formed were all identified to be an end-chain radical, equivalent to a polymer-chain propagating radical. The computer simulation disclosed that the observed spectra of the propagating radical can be approximated essentially by two kinds of component spectra, a large amount of triplet, and a small amount of quarter (a triplet of doublets). Thus, the existence of two major conformers in a single end-chain radical has been proposed. The ESR kinetics of the radical formation were further studied and its correlation with the nature of polymerization (the changes in molecular weight and polymer conversion) was discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080290405
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  • 3
    Electronic Resource
    Electronic Resource
    A novel hydrogen rearrangement of bifunctional o-xylylene derivatives in chemical ionization mass spectrometry (1994)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 8 (1994), S. 126-128 
    Details
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A novel hydrogen rearrangement reaction was found in benzyl ions that have a (benzyl) group (Z=O or N) at their ortho position. From deuterium labeling experiments, mass analyzed ion kinetic energy spectra with collisional activation, and examination of structure-peak intensity correlation, a mechanism is proposed which involves a direct transfer of hydrogen (hydride) to the structurally remote but spatially close cationic center. The possibility of an alternative, less likely mechanism including an ion/neutral complex and/or a proton-bridged complex has also been discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/rcm.1290080123
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  • 4
    Electronic Resource
    Electronic Resource
    Viscoelastic properties of polystyrene-poly(vinyl methyl ether) blends in oscillatory and steady shear flows near the phase separation temperature (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Polymer International 34 (1994), S. 327-331 
    Details
    ISSN: 0959-8103
    Keywords: polystyrene-poly(vinyl methyl ether) ; oscillatory shear flow ; steady shear flow ; shear induced homogenization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Viscoelastic properties of a polystyrene-poly(vinyl methyl ether) blend were measured in oscillatory and steady shear flows near the phase separation temperature. In the one-phase region, the viscoelastic properties are independent of the type of flow and flow geometry, and their shear and frequency dependences are the same as those of homopolymers. When phase separation occurred, a change in viscoelastic properties was observed in all types of flow and flow geometries, and they are different in the different types of flow and/or different flow geometries in the two-phase region.In the shear rate dependence of viscosity of the polymer blend in the two-phase region at quiescence, a plateau region was observed, in which the shear viscosity can be regarded as the zero shear viscosity of the homogenized polymer blend at that temperature.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pi.1994.210340313
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  • 5
    Electronic Resource
    Electronic Resource
    Involvement of superoxide radicals in the mouse two-cell block (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 28 (1991), S. 356-360 
    Details
    ISSN: 1040-452X
    Keywords: Oxygen toxicity ; Superoxide dismutase ; Embryo development ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effect of oxygen toxicity on the development of mammalian embryos was asssessed by the use of superoxide dismutase (SOD), a potent scavenger of superoxide radicals. Mouse pronuclear embryos recovered 17 h after human chorionic gonadotropin (hCG) were cultured in medium BWW at 37°C under an atmosphere of 5% CO2 in air. Culture of mouse pronuclear embryos in the presence of Cu ∣ Zn-SOD (500 μg/ml) significantly increased the blastulation rate (44.6%) when compared with the control culture system (4.2%). Essentially the same effects were observed in SOD containing either Mn or Fe in the catalytic center. Heat treatment of the SOD preparation, and the addition of anti-SOD antibodies to the culture medium, significantly reduced the attenuation of the two-cell block by SOD, indicating that this effect is SOD dependent. SOD activity was detected in rabbit oviduct fluid (3,675 ± 3,084 mlU/mg protein) by electron spin resonance. These results suggest that active oxygen is involved in the two-cell block phenomenon in mouse embryos exposed to air and that SOD in the oviduct may play an important role in the protection of embryos from superoxide radicals.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080280408
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  • 6
    Electronic Resource
    Electronic Resource
    Effects of oxygen toxicity on early development of mouse embryos (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 28-33 
    Details
    ISSN: 1040-452X
    Keywords: Mouse embryo ; Superoxide dismutase ; Low-oxygen culture ; Two-cell block ; Oxygen radical ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To examine the effects of oxygen toxicity on embryonic development, mouse pronuclear embryos were cultured under low oxygen conditions with or without superoxide dismutase (SOD), and the blastulation rate was compared with that of embryos cultured under standard conditions. The blastulation rate of mouse pronuclear embryos cultured under standard conditions was only 1.5% (2/131). This rate was increased significantly, to 28.5% (43/151), when the embryos were cultured under low oxygen conditions; and to 31.0% (35/113) when SOD (500 μg/ml) was added to the medium under standard conditions; the rate was increased to 75.2% (115/153) when the embryos were cultured under low oxygen conditions in the presence of SOD. The minimum effective concentration of SOD in the culture medium was 50 μg/ml under conditions of 5% O2. The blastulation rate was significantly decreased after 1-hr exposure of pronuclear embryos to room atmospheric oxygen concentration (20% O2), and subsequent culture under 5% O2 with SOD did not result in an improved blastulation rate. Culture with SOD under 5% O2 promoted the development of two-cell stage embryos to the blastocyst stage. When two-cell stage embryos were collected 48 hr after hCG and cultured for 66 hr, their blastulation rate was similar to that of embryos collected from mice 114 hr after hCG. These results suggested that embryonic development in vitro is greatly affected by atmospheric oxygen throughout the early embryonic stages and that this harmful effect can be prevented by culturing embryos under low oxygen conditions and in the presence of SOD.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310106
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of hydroxyapatite coating on bone growth into porous titanium alloy implants under loaded conditions (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Biomaterials 5 (1994), S. 23-37 
    Details
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Titanium alloy tibial segmented defect repair devices whose stems were coated with two layers of titanium alloy beads (Ti-6A1-4V, bead diameter c. 750 μm) were implanted in six beagle dogs. In four of the animals stems had been plasma-sprayed with hydroxyapatite (HA); the other two animals received devices with uncoated stems. Devices intended for 6-month and 3-month evaluation were implanted in right and left tibiae, respectively. Because the amount of bone ingrowth into pore spaces was greater in cortical bone than in cancellous bone, stems were more stable and firmer in the cortical bone. In stems coated with HA, new bone tissue came into contact with the surface of beads in the superficial layer of the stem faster than in stems not so coated. Furthermore, new bone tissue entered into pore spaces in these stems earlier, in larger amounts, and reached more deeply, binding directly to the beads. Rate and quality of bone ingrowth did not differ between the 3-month and 6-month tibiae; in other words, optimal bone ingrowth was attained within 3 months postimplantation. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jab.770050105
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  • 8
    Electronic Resource
    Electronic Resource
    Effects of the anabolic steroid nandrolone phenylpropionate on craniofacial growth in rats (1994)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 220 (1994), S. 25-33 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Primary testosterone and its derivatives are anabolic steroids used in the treatment of osteoporosis and Turner syndrome. They also enhance fast-twitch muscle weight in female rats. The present study examines the effect of an anabolic steroid on craniofacial growth and development in rats. Five-week-old female Sprague-Dawley rats (125) were divided into experimental and control groups. The experimental group was injected subcutaneously with 1 mg nandrolone phenylpropionate in the interscapular region on alternate days, whereas those in the control group were injected with a vehicle, arachis oil. Rats were sacrificed at 60 and 120 days of age. Cephalometric analysis of soft X-ray cephalograms showed that chronic administration of the anabolic steroid, nandrolone phenylpropionate, resulted in: (1) about a 20% increase in body weight, (2) an increase in total skull length, (3) elongation of the maxillary and mandibular incisors, (4) an increase in the depth of the antegonial notch, and (5) downward-forward growth of the viscerocranium against the neurocranium. These results suggest that nandrolone phenylpropionate may accelerate craniofacial growth and/or induce high functional activity of the masticatory muscles in female rats. © 1994 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052200104
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  • 9
    Electronic Resource
    Electronic Resource
    Sensitive determination of midazolam in human plasma by capillary gas chromatography with surface ionization detection (1992)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 15 (1992), S. 195-198 
    Details
    ISSN: 0935-6304
    Keywords: Capillary gas chromatography ; Surface ionization detection (SID) ; Midazolam ; Human plasma ; Simple extraction ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240150312
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  • 10
    Electronic Resource
    Electronic Resource
    Breakdown corrosion potential of ceramic coated metal implants (1990)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 24 (1990), S. 1111-1113 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820240813
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