introduction: the success of endodontic retreatment is related to the complete removal of the obturation material from the root canal system. the aim of this study was to evaluate the efficacy of mtwo r and protaper retreatment files in removing the resilon/epiphany system with or without chloroform during retreatment. materials and methods: sixty distal roots of first mandibular molars were pr...

The assessment of biodurability of man-made vitreous fibers is essential to the limitation of health hazards associated with human exposure to environments in which respirable fibers are present. In vitro acellular systems provide effective test methods of measuring fiber solubility provided care is taken to select the most suitable solvent and test conditions for the specific fiber type and di...

Different studies have demonstrated that solvents may induce auditory damage. It has been suggested that part of this damage may be localised in central auditory pathways. The present study aimed to investigate possible auditory processing disorders related to solvent exposure. Thirty solvent-exposed workers and 30 gender-, age- and educational level-matched control subjects were selected to pa...

Polyethersulfone (PES)-based anion exchange blend membranes were prepared from quaternized-PES (Q-PES) and N-Methyl-2-pyrrolidone (NMP) casting solutions with water as coagulant via non-solvent induced phase inversion. The compatibility of the blend system was investigated through thermodynamic studies while membrane formation was determined using the cloud point techni...

1. Introduction. In this paper we are interested in travelling wave solutions u = u(x; t) of the

Sesquiterpenes lactones including costunolide and dehydrocostus lactone, were isolated from Saussurea lappa roots, which had exhibited a wide range of biological activities such as anti-cancer, anti-inflammatory, antiulcer, and immunomodulatory activities. High-speed counter-current chromatography (HSCCC) was applied for the rapid preparative isolation of sesquiterpenes lactones from <...

Two significant advances are reported for solvent-based self-healing of epoxy materials. First, an autonomic system yielding complete recovery of fracture toughness after crack propagation was achieved by embeddingmicrocapsules containing amixture of epoxy monomer and solvent into an epoxy matrix. Healing with epoxy-solvent microcapsules is superior to capsules that contain solvent alone, and m...

the effect of different solvent systems on the extraction of antioxidant and anti radical agents of grape seed was studied. for this purpose 6 different solvent systems with similar polarity and different selectivity were used to prepare grape seed extract. extraction efficiency, reducing activity, radical scavenging property and the effect of each extract on the increase of thermal resistance ...