Ultrafast Light and Electrons: Imaging the Invisible

In this chapter, the evolutionary and revolutionary developments of microscopic imaging are overviewed with focus on ultrashort light and electrons pulses; for simplicity, we shall use the term “ultrafast” for both. From Alhazen’s camera obscura, to Hooke and van Leeuwenhoek’s optical micrography, and on to three- and four-dimensional (4D) electron microscopy, the developments over a millennium have transformed humans’ scope of visualization. The changes in the length and time scales involved are unimaginable, beginning with the visible shadows of candles at the centimeter and second scales, and ending with invisible atoms with space and time dimensions of sub-nanometer and femtosecond, respectively. With these advances it has become possible to determine the structures of matter and to observe their elementary dynamics as they fold and unfold in real time, providing the means for visualizing materials behavior and biological function, with the aim of understanding emergent phenomena in complex systems. Both light and light-generated electrons are now at the forefront of femtosecond and attosecond science and technology, and the scope of applications has reached beyond the nuclear motion as electron dynamics become accessible

1-year clinical evaluation of One-Step in non-carious cervical lesions

Purpose: To evaluate the 1-year clinical retention rate of restorations of non-carious cervical lesions placed using a "one-bottle" adhesive (One-Step) and one of two low modulus resin-based composite (RBC) restorative materials (Æliteflo or Bisco Glaze) or a microfilled RBC (Silux Plus). Materials and Methods: 105 non-carious cervical lesions in 14 patients, mean age 60 years, were restored using either Æliteflo, Bisco Glaze or Silux Plus with One-Step dentin bonding agent. The dentin surface was lightly roughened with a fine diamond stone, cleaned with pumice and water and restored according to the manufacturers' instructions. Patients were recalled at 6 months and 1 year, and the restoration sites examined. Results: At 6 months all restorations were present. At 1 year, five restorations were missing (two Silux, three Æliteflo), three of which were in one patient. A cumulative retention rate of 95% was recorded. A small number of restorations exhibited marginal discoloration, but this was believed to be due to excess RBC on unetched enamel.link_to_subscribed_fulltex