The aim of the present study was to investigate the serum levels of 6-keto-prostaglandin (PG)F1α and thromboxane (TX)B2, as well as the endothelialization and hyperplasia of polytetrafluoroethylene (PTFE) and Dacron prostheses seeded with CD34+ cells in medium-term observation. A total of 24 crossbred dogs were randomly distributed into PTFE or Dacron groups. CD34+ cells were isolated from bone...

A review is given of the development of the concept of an artificial tympanic membrane. Starting with homologous tympanic membranes we compared biodegradable collagen materials (homologous and heterologous) and biodegradable synthetic materials, poly-glycolic acid, poly-lactic acid and poly-alpha-amino acids. As a non-degradable material microporous PTFE and bisphenol-A poly (carbonate) were in...

A new internet-based synchrotron experiment for students is presented. A polarimeter and computer software have been developed for measuring via the internet the X-ray magnetic circular dichroism of PtFe around its Pt L(II) and L(III) absorption edges. From the experiment, students can examine the X-ray magnetic circular dichroism of a thin PtFe foil utilizing circular-polarized synchrotron rad...

An analytic robust model is developed for estimating GDL thermal conductivity. The model considers PTFE addition to the GDL. Thermal conductivity of MPL is accurately measured in a compression range of 2e14 bar. Effect of thermal conductivity on PTFE, MPL, and compression is considered. Thermal contact resistances between GDL and MPL/iron surface are measured. a r t i c l e i n f o

In this work, a new framework and model for the digital generation and characterization of the microstructure of gas diffusion layer (GDL) materials with localized binder and polytetrafluoroethylene (PTFE) distributions were developed using 3D morphological imaging processing. This new generation technique closely mimics manufacturing processes and produces complete phase-differentiated (void, ...

The electrostatic charge on nylon, polypropylene (PP), and polytetrafluoroethylene (PTFE) after rubbing against stainless steel and against each other was examined using a newly developed rubbing device with automated features. It is observed that the charge generated on PTFE and PP increases as the contact force increases, while the charge generated on nylon is not affected by the contact forc...

This study deals with preparation of substrates suitable for surface-enhanced Raman spectroscopy (SERS) applications by sputtering deposition of gold layer on the polytetrafluorethylene (PTFE) foil. Time of sputtering was investigated with respect to the surface properties. The ability of PTFE-Au substrates to enhance Raman signals was investigated by immobilization of biphenyl-4,4'-dithiol (BF...

Approximation of the previously estimated excess specific heat Cexcess/T 5 of two fluoropolymers, PTFE and PCTFE, is presented using Orthonormal Polynomial Expansion Method (OPEM). The new type of weighting functions in OPEM involves the experimental errors in every point of the studied thermal characteristic. The investigated temperature dependence of the function Cexcess/T 5 is described in t...

BACKGROUND/AIMS Primary repair of a large hiatal hernia is associated with a published recurrence rate of up to 10%; anecdotal rates even higher than this have been reported to the authors. The use of prosthetic material in the repair of other abdominal wall defects has often produced better results than primary repair. We wanted to compare laparoscopic primary repair of large hiatus hernias wi...

To test the alternative possible locations for the placement of a liver graft and the relevant surgical technique issues, we developed a porcine model of auxiliary partial heterotopic liver transplantation (APHLT) and evaluated the difference between 2 styles of liver transplantation, either subhepatic fossa or splenic fossa APHLT, by comparing survival and biochemical indexes. Thirty-eight min...