abstract background: after the umbilical cord is cut, premature neonates face numerous problems including hypothermia. with regard to serious complications of hypothermia and incapability of conventional methods in preservation of neonates’ temperature after admission, the researcher decided to conduct a study on the effects of two polyethylene covers in prevention of hypothermia among prematur...

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More than 60.000 hip arthroplasty are performed every year in Italy. Although Ultra-High-Molecular-Weight-Polyethylene remains the most used material as acetabular cup, wear of this material induces over time in vivo a foreign-body response and consequently osteolysis, pain, and the need of implant revision. Furthermore, oxidative wear of the polyethylene provoke several and severe failures. To...

An efficient and green procedure for the synthesis of 2, 4, 6-triaryl-1H-imidazole in polyethylene glycol under microwave irradiation in excellent yield has been developed. Polyethylene glycol is non toxic, reusable, inexpensive and easily available.

Abbreviations MEMS Microelectromechanical systems NEMS Nano-electromechanical systems PCL Polycaprolactone PET Polyethylene terephthalate PGA Polyglycolic acid PLA Polylactic acid PU Polyurethane PTFE Poly(tetrafl uoroethylene) PMMA Polymethylmethacrylate UHMWPE Ultrahigh molecular weight polyethylene

INTRODUCTION Highly crosslinked polyethylenes were introduced for hip arthroplasty more than 10 years ago [1]. The creation of highly crosslinked polyethylenes involves irradiation of the material followed by annealing or remelting. Higher doses of irradiation are desirable because it provides a sufficient level of cross-linking for wear reduction, which is why highly crosslinked polythethylene...

The elastic moduli of polymer-carbon nanotube composites are examined by molecular dynamics simulations of a single-walled carbon nanotube embedded in polyethylene. The overall system is modeled with a many-body bond order potential due to Brenner. Alternatively, only the carbon nanotube is modeled with Brenner’s potential and the polyethylene matrix is modeled by a united-atom potential. For t...

A dual mobility acetabular component has a structure that combines a polyethylene liner and a femoral head, unlike the general design of acetabular cups, making the dissociation of a polyethylene liner highly unlikely. In addition, it increases the range of motion and reduces the possibility of dislocations by increasing a jump distance. A fifty-one-year-old male who had received total hip arth...

Polyethylene wear has been accepted as a major cause of osteolysis in total hip arthroplasty. Submicron particles, which are secondary to abrasive wear, migrate into the effective joint space and stimulate a foreign-body response resulting in bone loss which is mainly mediated by macrophages. Diagnosis depends on serial radiographic evaluation and frequent follow-up. Polyethylene wear and osteo...

Polyethylene glycol dinitrates (PEGN) with molecular weights between 400 and 20 000 g·mol-1 were prepared from polyethylene glycols by esterification with nitric acid/sulfuric acid in dichloromethane. The products were characterized by gel permeation chromatography. The yield of PEGN increases with increasing reaction temperature (0-40 °C) however large liberation of nitrogen oxides was observe...