Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Hydroxyapatite induction by a synthesized pure silica hydrogel was examined in various simulated body fluids (SBFs) having different magnesium, calcium, and phosphate ion concentrations as well as pH values. The silica hydrogel generated biologically active apatite on its surface by taking up calcium and phosphorous ionic groups from a surrounding SBF that was prepared to emulate the human plasma in inorganic composition. The induction period for apatite nucleation on the surface of the silica was largely decreased with the addition of a small amount of the calcium or phosphate ions to the SBF and with an increase in pH, but increased with the addition of magnesium ion. Bioactivity of bioactive materials like Bioglass® and glass-ceramic A-W was well interpreted in terms of the rate of apatite formation reflected in these results. Moreover, the results provide the basic knowledge for designing new bioactive materials. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Through the oxygen exposure experiments on 3d transition metals (Cr, Fe, Co and Ni) and rare earth (Tb), we studied the initial oxidation by means of Auger peak-to-peak height (APPH) method. Based on the results obtained, a simple technique using the ratio of APPH was applied to the Auger depth profile analysis of magneto-optical disk (MOD). It was clearly indicated that the preferential oxidation of Tb occurred only at the lower interface between the TbFeCo and metal-oxide layers, and this technique can be used to obtain the chemical information about the interface oxidation in Auger depth profiling.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0142-2421
    Keywords: SIMS ; GaAs ; round-robin ; sensitivity factor ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Round-robin studies on relative sensitivity factors (RSFs) in secondary ion mass spectrometry (SIMS) were conducted using bulk GaAs samples uniformly doped with various impurity elements. A total of 31 laboratories participated in two round-robins. More than 30 sets of relative ion intensities were obtained for B, Si, Cr, Mn, Fe, Cu, Zn, In and Te in GaAs. The RSFs for both positive and negative ions were derived for several types of SIMS instruments. The effect of primary ion incident angle was examined using quadrupole-based instruments and found to be the determining factor of the instrumental dependence of RSF. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 117-118 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The chemical shift of V Kβ1, 3 and width of V Kα1 were measured with a two crystal X-Ray spectrometer. It was found that V Kβ1, 3 shift and V Kα1width can be utilized for identification of the vanadium oxidation state. Applications to vanadium containing catalysts and several perovskite structure compounds are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0021-9304
    Keywords: porous A-W GC ; bBMP ; rxBMP-4/7 ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: To accelerate the integration of ceramic implants with the surrounding bone and to search for a suitable carrier for bone morphogenetic protein (BMP), we studied ectopic bone induction in porous apatite-wollastonite-containing glass ceramic (A-W GC) combined with partially purified bovine BMP (bBMP) and recombinant Xenopus BMP-4/7 (rxBMP-4/7). Porous A-W GC rods [4 mm in diameter, 5 mm in height, 70% porosity, 200 μm mean pore size, 17.54 ± 3.82 MPa (mean ± SD) compressive strength] were used. An apatite coating formed on the surface of porous A-W GC that had been immersed in simulated body fluid at 36.5°C for 7 days. In experiment 1, porous A-W GC rods were combined with either bBMP, collagen, or with both bBMP and collagen. The rods were implanted into subcutaneous pouches in rats and were harvested 4 weeks after implantation. Low-energy radiographic, scanning electron microscopic (SEM), and histological examinations showed ectopic bone formation and within the rods only in the porous A-W GC combined with the bBMP and collagen group. Quantitative analysis also revealed that this group alone showed a significant increase in bone formation. In experiment 2, porous A-W GC rods were combined with rxBMP and collagen, implanted into rats, and harvested as described above. SEM and histological examination showed ectopic bone formation around and within the rods. Because of its relatively high mechanical strength, ease of handling, and good osteoinductivity, porous A-W GC combined with BMP and collagen may be clinically useful in patients with large cancellous bone defects or craniomaxillofacial lesions. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 35, 421-432, 1997.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0021-9304
    Keywords: titanium metal ; NaOH treatment ; bioactivity ; apatite ; simulated body fluid ; bonding strength ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Our previous study showed that titanium metal forms a bonelike apatite layer on its surface in simulated body fluid when it was subjected to NaOH and heat treatments to form a sodium titanate hydrogel or amorphous sodium titanate surface layer. In the present study, bonding strength of the apatite layer formed on the titanium metals to the substrates were examined under tensile stress, in comparison with those of the apatite layers formed on Bioglass 45S5-type glass, dense sintered hydroxyapatite, and glass-ceramic A-W, which are already clinically used. The NaOH-treated titanium metals showed higher bonding strength of the apatite layer to the substrates, which was maximized by heat treatments at 500 and 600 °C, than all the examined bioactive ceramics. It is believed that bioactive metals thus obtained are useful as bone substitutes, even under load-bearing conditions. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 38: 121-127, 1997
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The interfaces between four kinds of surfaceactive ceramic and bone were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using undecalcified specimens. The materials were Bioglass®-type glass (Bioglass®), Ceravital-type glass-ceramic (KGS), apatite and wollastonitecontaining glass-ceramic (A-W · GC) and hydroxyapatite (HA)· Particles of these materials, ranging between about 100 and 300 μm in diameter, were implanted into rat tibiae, and specimens were prepared for observation at 8 weeks after implantation. All materials were observed to bond to bone through a collagen-free layer consisting of fine apatite crytals distinct from those in bone. The crystals of this apatite layer and those of bone were intermingled at their interface, suggesting chemical bonding. In Bioglass®, which had only a glassy phase, several tens of microns of the material surface had changed to such an apatite layer. In KGS and A-W · GC, which had macrocrystals in the glassy phase, an intervening apatite layer about 0.5 μm thick was observed between the materials and bone. Furthermore, fine apatite crystals were also observed among the macrocrystals near the surface of the materials. In HA, which had no glassy phase, an intervening apatite layer was much less distinct and sometimes absent. These differences were considered to be attributable to the differences in chemical composition, crystallization, and solubility of the materials. © 1992 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: It has been proposed that the formation of a surface apatite layer in vivo on surface active ceramics is an essential condition for chemical bonding between ceramics and bone tissue. To clarify the difference in bone-bonding mechanisms between surface active ceramics and bioresorbable ceramics, two experiments were performed using plates of dense β-tricalcium phosphate (β-TCP). First, plates of β-TCP were implanted subcutaneously in rats for 8 weeks. Surface change due to bioresorption was observed with scanning electron microscopy. Formation of the apatite layer on the surface was investigated using thin-film x-ray diffraction and Fourier transform infrared reflection spectroscopy. Second, plates of β-TCP were implanted in tibiae of rabbits for 8 and 25 weeks and subjected to the detaching test to measure bone-bonding strength. β-TCP bonded strongly to bone. Undecalcified sections of the interface of bone and β-TCP were examined with SEM-EPMA. However, by physicochemical methods, no formation of surface apatite layer was observed. These results suggest that β-TCP bonds to bone through microanchoring between bone and rough surface of resorbed β-TCP.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The interface between bioactive ceramics and bone was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The materials were apatite-wollastonite-containing glass ceramic (A-W · GC) as a representative surface-active ceramic, and calcite and p-tricalcium phosphate (p-TCP) as resorbable ceramics. Particles of these materials, ranging between about 100 pm and 300 pm in diameter, were implanted into rat tibiae, and specimens were prepared for observation at 8 weeks after implantation. Both SEM and TEM demonstrated that A-W · GC was bonded t o bone through a thin Ca-P-rich layer consisting of fine apatite crystals apparently different from those of bone in shape, size, and orientation. Collagen fibers of the bone reached the surface of this layer, and chemical bonding between A-W · GC and the bone was speculated. Calcite and p- TCP, on the other hand, made direct contact with the bone, and no apatite layer was present at the interface. The surfaces of the implants became rough due to degradation, and bone grew into the finest surface irregularities. However, we were unable to demonstrate any continuity of crystals between the resorbable implants and bone by high-resolution TEM. Ac- cordingly, the bonding strength was considered to be mainly attributable to mechanical interlocking.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...