BACKGROUND Frontalis suspension surgery is considered the procedure of choice in cases of blepharoptosis. Among all the materials used in this type of surgery, ophthalmic and plastic surgeons prefer to use autologous Fascia Lata. However, during years, other autogenous and exogenous materials have been introduced. OBJECTIVES The aim of this study was therefore that of systematically reviewing...

CONTEXT Reports of polytetrafluoroethylene (PTFE) bypass grafting to the infrapopliteal arteries have often used survival analysis of acceptable quality to describe a wide range of long-term results. In theory, these results may be combined if variability between series and time intervals is considered. OBJECTIVE Meta-analysis was performed to gain insight into long-term graft patency and foo...

The residual effects of cumulative thermal aging on the crystal structural characteristics of the fluoro carbon poly(tetra fluoro ethylene) (PTFE) have been studied by X-ray diffraction methods. The initial hexagonal arrangement of the PTFE chains in a 157 helical conformation is left unaffected by the exposures to temperatures (T), up to and beyond its melting point, Tm. The unit cell register...

We appreciate the fluency of the original article by Uzun et al. (1) entitled “Long-term patency of autogenous saphenous veins vs. PTFE interposition graft for prosthetic hemodialysis access,” which was recently published in Anatol J Cardiol 2014; 14: 542-6.” The authors divided the study population in two groups, those who used autogenous saphenous grafts and those who used PTFE. Although the ...

AIM Published clinical series suggest the osteoodontokeratoprosthesis (OOKP) may have a lower extrusion rate than current synthetic keratoprostheses. The OOKP is anchored in the eye wall by autologous tooth. The authors' aim was to compare adhesion, proliferation, and morphology for telomerase transformed keratocytes seeded on calcium hydroxyapatite (the principal mineral constituent of tooth) ...

Functionalization of Polytetrafluoroethylene (PTFE) powders of ~6 μm particle size is carried out using low-pressure 2.45 GHz H2, NH3 microwave plasmas for various durations (2.5, 10 h) to chemically modify their surface and alter their surface energy. The X-ray Photoelectron Spectroscopy (XPS) analyses reveal that plasma treatment leads to significant defluorination (F/C atomic ratio of 1.13 a...

The influence of pad facing material on hydrodynamic lubrication in tilting-pad thrustbearings is investigated in terms of pad and oil-film temperatures and oil-film thickness. Two tilting-pad thrust bearings are examined: one with babbitt pad facing, the other with a layer of a PTFE based composite material. Frictional torque, pad, collar and oil-film temperatures and oil-film thicknes...

Metal/fluoropolymer composites represent a new category of energetic structural materials that release energy through exothermic chemical reactions initiated under shock loading conditions. This paper describes an experiment designed to study the reaction characteristics of energetic materials with low porosity under explosive loading. Three PTFE (polytetrafluoroethylene)/Ti/W mixtures with dif...

Abstract Carbon fibre/fabric (CF) is a privileged reinforcement for advanced polymer composites in tribological applications where performance is primary criteria rather than the cost due to the combination of distinct properties such as high specific strength, thermo-oxidative resistance, thermal and electrical conductivity along with self-lubricity etc. However problems associated with its ch...

over a seven year period from 1982 to 1989,3337 conduits were created in 3137 patients with end stage renal disease (esrd) as access for chronic dialysis. these included 2690 side-to-side arteriovenous fistulae (a vf), 168 end-to-side a vfs, 10 autogenous vein grafts, 51 homogenous frozen vein grafts, 109 polytetrafluoroethylene (ptfe) grafts, 209 emergency external arteriovenous shunts, three ...