Esophageal stenting has been shown to be a convenient and long-lasting method of palliation for malignant dysphagia.1 Use of covered self-expandable metal stents (SEMS) and, more recently, self-expandable plastic stents (SEPS)2 has led to increased success rate in the palliative treatment of malignant strictures of the esophagus. Experience with SEPS is scant. We report our experience with the ...

BACKGROUND This report describes a one-step insertion of an expandable metallic stent to treat obstructive jaundice due to unresectable common bile duct carcinoma. METHODS A percutaneous transhepatic cholangiogram is obtained, and the bile duct obstruction is negotiated with a guide wire. After advancing the catheter into the duodenum, contrast material is injected to measure the length of th...

Transcatheter treatment of aortic coarctation, with balloon angioplasty or stent implantation, is now an acceptable alternative to surgical repair. However these procedures may result in complications, such as vascular wall injury and re-stenosis of the lesion. A nitinol self-expandable stent, when deployed at the coarctation site, produces low constant radial force, which may result in a gradu...

OBJECTIVE Balloon-expandable stent valves require flow reduction during implantation (rapid pacing). The present study was designed to compare a self-expanding stent valve with annular fixation versus a balloon-expandable stent valve. METHODS Implantation of a new self-expanding stent valve with annular fixation (Symetis, Lausanne, Switzerland) was assessed versus balloon-expandable stent val...

Polystyrene nanoring arrays with outer diameters ranging from 130 to 230 nm were fabricated using low cost and simple fabrication techniques, including nanosphere lithography, argon plasma treatment, immersion in organic solvents and sonication. These nanorings were developed from polystyrene nanospheres pre-assembled on substrates. Scanning electron microscopy revealed that the argon plasma tr...

Polystyrene grafted with acrylonitrile using gamma-irradiation technique was successfully synthesized. This process was carried out at various gamma dose (0.2-1.5 Mrad). The new grafted polymer was characterized and its properties were investigated. The results indicate that best grafting percentage ratio could be revealed when the concentration of the catalyst Ferrous Ammonium Sulphate (FAS) i...

The adhesion of Streptococcus mitis to solid substrata from phosphate suspensions with various ionic strengths was studied and compared with the adhesion of polystyrene particles. At all ionic strengths, the interfacial free energy of adhesion governed the relative number of bacteria or polystyrene particles adhering at equilibrium, except that in a low-ionic-strength buffer, adhesion occurred ...

The main goal of this study was to prepare and characterize ion exchangers on nanofibrous polystyrene matrix. Starting nanofibers were sulfonated and crosslinked at the same time by sulfuric acid. Strongly acidic cation exchanger was obtained in such a way. Anion exchanger was prepared by reaction of ethylene diamine with sulfochlorides on nanofibers acquired from sulfogroups. The polymer matri...

Thin films of polystyrene on silicon substrate were investigated for thickness-dependent interface properties. To better understand the desirable electrical, mechanical, and optical properties of a polymer thin film, the interfacial structures must be first understood. Using x-ray reflectivity, data from polystyrene-air and polystyrene-silicon interfaces were collected and correlated with a the...