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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 155 (1968), S. 0 
    ISSN: 1749-6632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Allgemeine Naturwissenschaft
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 155 (1969), S. 0 
    ISSN: 1749-6632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Allgemeine Naturwissenschaft
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 113 (1964), S. 0 
    ISSN: 1749-6632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Allgemeine Naturwissenschaft
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Journal of School Psychology 29 (1991), S. 319-329 
    ISSN: 0022-4405
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Psychologie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Mund-, Kiefer- und Gesichtschirurgie 3 (1999), S. S147 
    ISSN: 1434-3940
    Schlagwort(e): Schlüsselwörter Fluoreszierende Mikrosphären ; Ossäre Perfusion ; Mikrozirkulation ; Key words Fluorescent microspheres ; Osseous perfusion ; Microcirculation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary The aim of this study was to establish a novel model permitting repetitive analysis of osseous perfusion over a period of 33 days using the fluorescent microsphere technique. After implantation of two port systems into the right and left carotid artery in New Zealand rabbits (n = 3), fluorescent microspheres were injected into the left ventricle, while blood samples for reference probes were taken from the descending aorta. Using seven different fluorescently labeled microspheres, injections were repeatedly performed starting 3 days after implantation (t = 0) at days 1, 3, 5, 12, 19, 26, and 33. Osseous blood flow was semiquantitatively analyzed by counting the number of trapped microspheres within the bone sections performed through the distal femur condyle (n = 8) using a fluorescence microscope. Over the entire observation period of 33 days, intraindividual variance in the number of trapped microspheres was low, while there were marked interindividual differences between animals. The mean osseous perfusion in the three animals evaluated so far remained constant over the observation period of 33 days. The present model is the first to allow repetitive analysis of osseous perfusion over an observation period of 33 days. Using this model, the role of regional osseous perfusion can be studied under conditions such as impaired bone healing following radiotherapy- and/or chemotherapy, implantation of biomaterials, and transplantation of bone.
    Notizen: Zusammenfassung Fragestellung: Es war das Ziel der vorliegenden Untersuchung, ein neues Modell zu etablieren, das es erlaubt, unter Verwendung fluoreszierender Mikrosphären den Blutfluß im Knochen über einen Zeitraum von 33 Tagen repetitiv zu erfassen. Material und Methode: Nach Implantation von jeweils einem Portsystem in die Aa. carotis dextra und sinistra bei Neuseelandkaninchen (n = 3) erfolgten die Injektion von Mikrosphären in den linken Ventrikel einerseits sowie die Entnahme einer Referenzprobe aus der Aorta descendens andererseits. Unter Verwendung von insgesamt 7 verschiedenen fluoreszenzmarkierten Mikrosphären wurde 3 Tage nach der Implantation (t = 0) die Injektion an den Tagen 1, 3, 5, 12, 19, 26 und 33 durchgeführt. Der Blutfluß wurde semiquantitativ erfaßt, indem die im Bereich des distalen Femurs gewonnenen Knochensägeschnitte (n = 8) unter dem Fluoreszenzmikroskop im Hinblick auf die Zahl der arretierten Mikrosphären ausgezählt wurden. Ergebnisse: Innerhalb der Tiere war über den Beobachtungszeitraum von 33 Tagen nur eine geringe intraindividuelle Varianz der Meßwerte zu erkennen, während interindividuell deutliche Unterschiede zwischen den Tieren nachweisbar waren. Die mittlere ossäre Durchblutung in den bisher 3 ausgewerteten Tieren blieb über den Beobachtungszeitraum von 33 Tagen konstant. Schlußfolgerungen: Mit dem vorliegenden Modell ist es erstmals möglich, Veränderungen der ossären Durchblutung über einen Zeitraum von 33 Tagen repetitiv zu messen. Damit könnte bei Störungen der Knochenheilung, wie etwa nach Radio- und/oder Chemotherapie, bei Implantation von Biomaterialien sowie Transplantation von Knochen der Stellenwert der regionalen Durchblutung des Knochens repetitiv erfaßt werden.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Optics Communications 32 (1980), S. 133-135 
    ISSN: 0030-4018
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Optics Communications 28 (1979), S. 213-216 
    ISSN: 0030-4018
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 16 (1982), S. 679-704 
    ISSN: 0021-9304
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin , Technik allgemein
    Notizen: It has been argued that various specific requirements based on known principles of good adhesion are not being met in the current procedures of formation of the implant-bone cement interface. It has been shown that an annealed thin film PMMA precoating, applied in a low-contact-angle form to surgical alloy surfaces devoid of weak boundary layers, satisfies the majority of the requirements during interface formation. Techniques for the application of the precoating have been developed for SS316LVM, Co-Cr-Mo, and Ti-6Al-4V based on fracture toughness and fatigue tests, and fractography of the interface. Implant surface preparation methods have been established to yield surfaces amenable to adhesive bonding. The composition of the coatings have been studied from the point of view of implant surface wetting, coating roughness and thickness, and interface strength. A biocompatible silane coupling agent (A-174), currently used in orthodontics, has been introduced to provide saline resistant interfaces. The final precoated metal-bone cement interfaces have demonstrated fracture toughnesses in excess of that of bone cement even after prolonged exposure to 37°C physiological saline. Fatigue tests have shown that the fatigue lives (6.5 MPa) of the precoated metal interfaces in saline are at least twice, and in one case several orders of magnitude greater than, that of the uncoated ones even when the latter are tested dry. Fractography of the interfaces show failures that are entirely cohesive in nature. For the UHMWPE (ultrahigh molecular weight polyethylene)-bone cement interface, similar improvement with precoating, however, could not be attained. Finally, the coated metal-bone cement interfaces have been tested as a function of some clinical variables such as cement type, joining time, clinical contamination, and sterilization procedure. Results show that coated metals exhibit a certain level of insensitivity to these variables and retain their performance under all conditions except after particular repeated sterilizations.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 15 (1981), S. 159-182 
    ISSN: 0021-9304
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin , Technik allgemein
    Notizen: Loosening is a major cause of failure in total arthroplasties. The efficacy of the fixation systems depends not only on the bulk properties of the components but also on the interfaces through which they interact. This study was initiated to examine the implant/bone-cement interface for four of the most commonly used implant materials, Co—Cr—Mo, Ti—6Al-4V, 316SSLVM and ultrahigh molecular weight polyethylene (UHMWPE). The surface preparation, specimen design, joining, and testing techniques were studied and then standardized in a manner which accurately represents current clinical procedures. The interfaces were tested for both their quasistatic and fatigue properties. Finite-element and fracture toughness analyses of the quasistatic shear specimens were performed in order to provide results of an absolute nature which could be subsequently compared to bulk material properties of bone cement. The interfaces were tested “dry” (i.e., at room temperature and 50% R.H.) and in physiological saline at 37°C. The interfaces demonstrated both fracture toughness and fatigue properties far inferior to those of bone cement. A predominantly interfacial type failure was observed using SEM fractography. The ultimate compressive strength (U.C.S.) of bone cement was measured after prolonged exposure to saline at 37°C and showed no decrease in U.C.S. suggesting that the reasons for the interface strength reductions were interfacial rather than bulk in nature. The “wetting'” ability of bone cement was measured using contact angles at various cure times on the four implant materials. These measurements showed that intimate interfacial contact is impossible with current clinical methods. This study indicates that failure of the implant/bonecement interface is likely only a short period after implantation and therefore may be a major contributor to implant loosening.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Hoboken, NJ [u.a.] : Wiley-Blackwell
    Journal of Orthopaedic Research 2 (1984), S. 105-118 
    ISSN: 0736-0266
    Schlagwort(e): Stem prosthesis loosening ; Bone cement ; Metal/cement interface ; Precoating ; Fracture mechanics ; Life and Medical Sciences
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: To characterize the strength of the interface between stem-type metal implants and bone cements, a fracture mechanics parameter was used. This parameter, the critical strain energy release rate (Gc), was determined from “push-out” tests of cylindrical specimens. The specimens, formed using molds of bone, were maintained and tested at body temperature. The strength of interfaces formed with cancellous bone surrounding the cement mantle was significantly less than the strength of those formed in apposition to cortical bone. A marked degradation of strength was found with saline immersion for SS316LVM/cement interfaces formed with Zimmer regular, Simplex-P, and Zimmer LVC cements. After 60 days of immersion the interface Gc was only 10-20% of the value for bulk cement. Interfaces formed with thin-film polymethylmetharcrylate-precoated metals (SS316LVM, Co-Cr-Mo, and Ti-6A1-4V) yielded “dry” Gc values one order of magnitude greater than those measured with interfaces formed with uncoated metals. Moreover, the strength of precoated SS316LVM/cement interfaces formed with all three brands of cement did not change after saline immersion for 60 days.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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