OBJECTIVES The aim of this in vitro study was to evaluate the influence of different light curing units and modes on microleakage of flowable composite resins. METHODS Eighty Class V cavities were prepared in buccal and lingual surfaces of 40 extracted human premolars with cervical wall located in dentin and the occlusal wall in enamel. These teeth were randomly assigned into two groups (n=20...

Highly fluorinated epoxides were polymerized under mild conditions regioregularly, which gave easy access to isotactic polymers by using optically pure epoxides.

Borysko and Sapranauskas (1) and independently Gay (2) have described a method of making coverslip preparations of biological material from which small selected cell groups or single cells may be transferred to methacrylate for sectioning for electron microscopy. In both procedures it is suggested that the selected material viewed under light and phase microscopy be covered with a capsule conta...

Differential scanning calorimetry (DSC) analysis of ring opening methatesis polymerization (ROMP) derived polydicyclopentadiene (PDCPD) revealed an unexpected thermal behavior. A recurring exothermic signal can be observed in the DSC analysis after an elapsed time period. This exothermic signal was found to be proportional to the resting period and was accompanied by a constant increase in the ...

Abstract: The phase structure of self-avoiding polymerized membranes is studied by extensive Hybrid Monte Carlo simulations. Several folding transitions from the flat to a collapsed state are found. Using a suitable order parameter and finite size scaling theory, these transitions are shown to be of first order. The phase diagram in the temperature-field plane is given. PACS numbers: 87.22.Bt –...

Connection between discrete and continuum models of polymerized (tethered) surfaces has been investigated by applying a transfer matrix method to a discrete rigid-bond triangular lattice, which is allowed to fold on itself along its bonds in a two-dimensional embedding space. As its continuum counterpart, the model has an extensive entropy and the mean squared distance between two sites of a fo...

The mechanism by which trophozoites of the protozoan parasite, Entamoeba histolytica destroy mammalian cells is not clear. A variety of amoeba-associated properties have been correlated with virulence (reviewed in 1 and 2). In vitro studies (3-6) have shown that contact of the trophozoite with a target cell is required. Contact killing has been described (6) as occurring in the sequence: adhere...