ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 25 (1987), S. 1903-1911 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The permittivity and loss of poly(methyl methacrylate) (PMMA) network crosslinked with trimethylol-1,1,1 propane and its interpenetrating network polymers with 10, 34, and 50% (by weight) poly(urethane) have been measured from 100 to 400 K over a frequency range of 12 to 1 × 105 Hz. Two relaxation processes, γ and β, are observed in the PMMA network, and a third process, αpu, in the 10% poly(urethane) IPN. At higher concentrations of poly(urethane), the γ process is removed from the temperature-frequency range of our study. Crosslinking in pure PMMA slows the segmental motions involved in the β process and raises its activation energy. Physical aging of the 10 wt% poly(urethane)-PMMA causes its γ process to become indiscernible and the αpu process to become better resolved. A discussion of these results in terms of local regions of segmental motion is provided.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Biomaterials 2 (1991), S. 29-35 
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Anteior cruciate ligament (ACL) grafts made from expanded polytetrafluorethylene (ePTFE) were examined after failure (n = 7; 3 instabilities, 2 partial and 2 complete ruptures) to provide information about secondary fixation mechanisms via ingrowth of the different tissues. The ultrastructural evaluation clearly evidenced the existence of two main interface areas of ePTFE ACL-replacement: First, in areas without a dense cellular infiltrate there was interdigitating collagen producing a dense ePTFE-collagen network. Additionally, in a few areas of the graft/bone-tunnel interface a fibrous cartilage or bone regenerate could be demonstrated to be in contact with the prosthesis. Second, there was a dense infiltration of macrophages and multinuclear giant cells, partially containing birefringent material of implant origin, with and without a neosynovia-like reaction product, indicating a disturbance of tissue integration of the prosthesis. In areas of inflammation there was no bone development and only few collagen interdigitation with the graft material. This study provides further knowledge about mechanisms of secondary graft fixation due to tissue ingrowth. The interdigitation of collagen fibers and ePTFE filaments provides interfaces which should be at least partially resistant against load.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Type, size and distribution of extracellular matrix vesicles (MV), known mediators of primary calcification, were studied around bone-bonding and metal-oxide containing, nonbonding, glass-ceramic implants. This was performed in order to further understand the different effects of implants on bone healing. At 14 days after implantation in adult rat tibial bone the effects of different implants on MV were studied by transmission electron microscopy and computerized morphometry. A total number of 4607 MV in 245 electron micrographs were counted and grouped according to diameter, distance from the calcifying front, and classified as four types: “empty,” “amorphous,” “crystal,” and “rupture.” The sequence of types according to diameter and distance was recorded as follows around both implants tested: “rupture” MV were the closest to the front with the largest diameter, followed by “crystal,” “amorphous,” and “empty,” MV with the largest distance from the front and the smallest diameter. Most vesicles were concentrated in a distance of less than 2.4 μm from the front and between diameters of 0.06 μm and 0.22 μm. The noncalcified extracellular matrix around bone-bonding implants contained more MV than the matrix around the nonbonding type (26.24 MV/10 μm2 and 18.76 MV/10μm2). MV distribution according to type showed that around bonding implants ther was a higher percentage of “crystal” and a lower percent age of “rupture” when compared to the nonbonding type. These results indicate that bonding implansts affect osteoblastic function by increasing tht vesicular number and retardation of intravesicular crystal fromation. It might be suggested that bonding implants induce an increase in the process of primary calcification and a decreased rate of crystal formation resulting with the highest organization of the healing bone.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 29 (1995), S. 9-18 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: This article reports on the reaction of bone to a new family of nanocrystalline hydroxyapatite biomaterials with crystal sizes similar to those of human bone. Pure nanoapatite cylinders and organoapatite cylinders containing a synthetic nanopeptide were analyzed 28 days after implantation into the spongy bone of Chinchilla rabbits. The experimental techniques used for analysis were light microscopy, scanning electron microscopy, and transmission electron microscopy. Both implant types were well incorporated, and interface events were found to be similar to those observed on human bone surfaces with regard to resorption by osteoclast-like cells and bone formation by osteoblasts. Different types of giant cells were observed resorbing the outermost surfaces of implants. There seemed to be both dissolution of the implant and particulate biodegradation leading to less dense implant regions near the interface, whereas the bulk of the implants remained denser. Transmission electron micrographs revealed that bone bonding occurred with and without an afibrillar intervening layer. Given the biologic reaction observed, these implant materials should be suitable for bone replacement and the organoapatite form could be useful for additional functions such as the release of drugs and optimized release of antibiotics, growth factors, or other substances. The organic component can also be used to control physical properties in a bony implantation bed. © 1995 John Wiley & Sons, Inc.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 17 (1904), S. 1601-1605 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...