New Solution for Low Mass Hip Prostheses using Carbon Fiber

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

Download Full-text

Novel methods for demonstrating osseointegration of hydroxylapatite-coated titanium hip prostheses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084478 ◽

1991 ◽

Vol 49 ◽

pp. 34-35 ◽

Cited By ~ 1

Author(s):

P. Frayssinet ◽

J. Hanker ◽

D. Hardy ◽

B. Giammara

Keyword(s):

Hip Prosthesis ◽

Ethanol Concentration ◽

Bone Matrix ◽

Electron Microscopic Examination ◽

Electron Microscopic ◽

Hip Prostheses ◽

Cellular Inclusions ◽

Microscopic Studies ◽

Diamond Saw ◽

Plasma Sprayed

Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed methods allowing light and electron microscopic studies as well as microanalysis of the interface between bone and a metal biomaterial coated by plasma-sprayed hydroxylapatite(HA) ceramic.An HA-coated titanium hip prosthesis (Corail, Landos, France), which had been implanted for two years, was removed after death (unrelated to the orthopaedic problem). After fixation it was dehydrated in solutions of increasing ethanol concentration prior to embedment in polymethylmethacrylate(PMMA). Transverse femur sections were obtained with a diamond saw and the sections then carefully ground to a thickness of 200 microns. Plastic-embedded sections were stained for calcium with a silver methenamine modification of the von Kossa method for calcium staining and coated by carbon. They have been examined by back-scatter SEM on an ISI-SS60 operated at 25 KV. EDAX has been done on cellular inclusions and extracellular bone matrix.

Download Full-text

Effects of high pressure on the crystallization of carbon fiber reinforced polyetheretherketone (CF/PEEK) laminate composites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177519 ◽

1990 ◽

Vol 48 (4) ◽

pp. 876-877

Author(s):

Hong-Ming Lin ◽

C. H. Liu ◽

R. F. Lee

Keyword(s):

High Pressure ◽

Carbon Fiber ◽

Sample Surface ◽

High Yield ◽

Fiber Reinforced ◽

Laminate Composites ◽

Peek Composite ◽

Continuous Carbon Fiber ◽

Carbon Fiber Reinforced

Polyetheretherketone (PEEK) is a crystallizable thermoplastic used as composite matrix materials in application which requires high yield stress, high toughness, long term high temperature service, and resistance to solvent and radiation. There have been several reports on the crystallization behavior of neat PEEK and of CF/PEEK composite. Other reports discussed the effects of crystallization on the mechanical properties of PEEK and CF/PEEK composites. However, these reports were all concerned with the crystallization or melting processes at or close to atmospheric pressure. Thus, the effects of high pressure on the crystallization of CF/PEEK will be examined in this study.The continuous carbon fiber reinforced PEEK (CF/PEEK) laminate composite with 68 wt.% of fibers was obtained from Imperial Chemical Industry (ICI). For the high pressure experiments, HIP was used to keep these samples under 1000, 1500 or 2000 atm. Then the samples were slowly cooled from 420 °C to 60 °C in the cooling rate about 1 - 2 degree per minute to induce high pressure crystallization. After the high pressure treatment, the samples were scanned in regular DSC to study the crystallinity and the melting temperature. Following the regular polishing, etching, and gold coating of the sample surface, the scanning electron microscope (SEM) was used to image the microstructure of the crystals. Also the samples about 25mmx5mmx3mm were prepared for the 3-point bending tests.

Download Full-text

Enhanced performance of supercapacitors by constructing a “mini parallel-plate capacitor” in an electrode with high dielectric constant materials

Journal of Materials Chemistry A ◽

10.1039/d0ta04364h ◽

2020 ◽

Vol 8 (32) ◽

pp. 16661-16668

Author(s):

Huayao Tu ◽

Shouzhi Wang ◽

Hehe Jiang ◽

Zhenyan Liang ◽

Dong Shi ◽

...

Keyword(s):

Dielectric Constant ◽

Carbon Fiber ◽

Parallel Plate ◽

Sandwich Structure ◽

High Dielectric Constant ◽

Parallel Plate Capacitor ◽

Plate Capacitor ◽

Fiber Metal ◽

High Dielectric ◽

Mini Plate

The carbon fiber/metal oxide/metal oxynitride layer sandwich structure is constructed in the electrode to form a mini-plate capacitor. High dielectric constant metal oxides act as dielectric to increase their capacitance.

Download Full-text

Very Low-Mass Stars and Brown Dwarfs

10.1017/cbo9780511564758 ◽

2000 ◽

Cited By ~ 2

Keyword(s):

Brown Dwarfs ◽

Low Mass Stars ◽

Low Mass

Download Full-text

Modification of activated carbon fiber pore structure by coke deposition

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2001335 ◽

2001 ◽

Vol 11 (PR3) ◽

pp. Pr3-279-Pr3-286

Author(s):

X. Dabou ◽

P. Samaras ◽

G. P. Sakellaropoulos

Keyword(s):

Activated Carbon ◽

Carbon Fiber ◽

Pore Structure ◽

Activated Carbon Fiber ◽

Coke Deposition

Download Full-text

Analysis of 18F-FDG uptake patterns in PET for diagnosis of septic and aseptic loosening after total hip arthroplasty

Nuklearmedizin ◽

10.1055/s-0038-1625733 ◽

2003 ◽

Vol 42 (06) ◽

pp. 234-239 ◽

Cited By ~ 21

Author(s):

T. Mumme ◽

P. Reinartz ◽

D. Wirtz ◽

F. U. Niethard ◽

U. Büll ◽

...

Keyword(s):

Aseptic Loosening ◽

Femoral Component ◽

Hip Prosthesis ◽

Prosthetic Infection ◽

Clinical Value ◽

Septic Loosening ◽

Hip Prostheses ◽

Fdg Uptake ◽

Positron Emission ◽

Painful Hip

Summary Aim: Identification of typical patterns for fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) to detect aseptic loosening of hip prosthesis (ace-tabular and/or femoral component) and prosthetic infection. Methods: 18 patients with painful hip prosthesis underwent PET using a dedicated full ring scanner after application of 200-300 MBq FDG. The interface between bone and surrounding soft tissue or bone as displayed on coronal slices was divided into 12 segments in accordance with the classifications of Delee and Gruen. FDG uptake in each of the segments was scored (0-3) by two independent observers. Intraoperative findings were regarded as the gold standard. Results: After surgical revision 14 acetabular components and 9 femoral components were found to be loose and prosthetic infection was present in 7 prostheses. Loosening of the acetabular component was correlated to enhanced uptake in the middle of the acetabular interface, while loosening of the femoral component was correlated to enhanced uptake in the proximal and middle segment of the lateral femoral interface and the proximal segment of the medial femoral interface. A similar pattern was found in prosthetic infection with high uptake along the middle portion of the lateral fe-moral interface. In 6 of 7 infected prostheses loosening of the acetabular and of the femoral component was present. Taking the typical uptake patterns as criteria for loosening and grade 3 uptake as an additional criterion for septic loosening the accuracy of PET imaging in the detection of loosening of the acetabular or the femoral component and of prosthetic infection was 72, 78 and 89%, respectively. Conclusion: This pilot study presents FDG-PET as a promising diagnostic tool for patients with painful hip prostheses. Its clinical value should be evaluated in a larger patient population.

Download Full-text