objective: different methods have been suggested to overcome the polymerization shrinkage of composite restorations. changing the light curing protocol to improve polymerization by using new light curing units is among these methods. the new devices are more efficient, portable and durable and produce less heat. this study aimed to assess the marginal microleakage of class v composite restorati...

adhesive bonding technology is being used in a variety of modern industries, including the automotive, aerospace, maritime, construction, defense and so on. on the other side, polymeric nano - composites attracted both academic and industrial interests in the past decades. the scope of this paper is experimental investigation on the effects of the addition of alpha-alumina nanoparticles to the ...

Understanding the impact of noise on marine fauna at the population level requires knowledge about the vulnerability of different life-stages. Here we provide the first evidence that noise exposure during larval development produces body malformations in marine invertebrates. Scallop larvae exposed to playbacks of seismic pulses showed significant developmental delays and 46% developed body abn...

There is an increasing number of ventilated patients who require aerosol medications, for various indications. While there are many studies of aerosol delivery through tracheostomy and endotracheal tubes in patients on mechanical ventilation, and also in patients with noninvasive positive pressure ventilation,1 a relatively neglected area of aerosol therapy is in non-ventilated patients, and pa...

Removal of large segments of the apical part of the stipe of Coprinus cinereus (extending to about half its length) affected neither the ability of the stipe to show gravitropic bending nor its ability to compensate the curvature so induced and adjust to the vertical. However, gravitropic reaction time was directly proportional to the amount of stipe removed. Application of lateral loads of up ...

American National Standards Institute (ANSI) standard Z88.10, Respirator Fit Testing Methods, includes criteria to evaluate new fit-tests. The standard allows generated aerosol, particle counting, or controlled negative pressure quantitative fit-tests to be used as the reference method to determine acceptability of a new test. This study examined (1) comparability of three Occupational Safety a...

This article gives an overview of recent research on the mechanical properties and spatial deformations of the DNA molecule. Globally the molecule behaves like a uniform elastic rod, and its twisting and writhing govern its compaction and packaging within a cell. Meanwhile high mechanical stresses can induce structural transitions of DNA giving, for example, a phase diagram in the space of the ...

Symmetric couplings among aggregates of n chromophores increase the transfer rate of excitons by a factor n(2), a quantum-mechanical phenomenon called 'supertransfer'. In this work, we demonstrate how supertransfer effects induced by geometrical symmetries can enhance the exciton diffusion length by a factor n along cylindrically symmetric structures, consisting of arrays of rings of chromophor...

There are important physiological and pathological cardiovascular consequences related to endothelial biomechanical properties. The endothelium, however, is not unique in responding to external forces; virtually all cells accommodate or respond to the mechanical environment.