We report real-time observations of the folding and melting of DNA by probing two active sites of a hairpin structure, the bases and the stem end, and using an ultrafast T-jump. Studies at different initial temperatures (before, during, and after melting) provide the time scale of water heating (<20 ps), single-strand destacking (700 ps to 2 ns), and hairpin destacking (microseconds and longer)...

The purpose of this study was to evaluate the effect of degradation of a denture base resin on bond strength to relining resins. Denture base resin specimens were immersed under various conditions to simulate degradation. Tensile bond strength of denture base resin after immersion to relining resins was measured with or without surface grinding. The bond strength of denture base resin without g...

polymethyl methacrylate (pmma), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. this study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of com...

introduction: evaluation of bonding in atomic level, by sem/eds analysis of si atoms, is an exact method for determination of bond strength of metal and porcelain. the purpose of this study was to evaluate the bond strength of one noble alloy and two base metal alloys with and without beryllium. methods and materials: six specimens of each alloy begostar, rexillium iii, wiron 99 (10×10×1mm dime...

this paper deals with the interfacial effects of silica fume (sf) and styrene-butadiene polymer (sbr) on compressive strength of concrete. analyzing the compressive strength results of 32 concrete mixes performed over two water-binder ratios (0.35, 0.45), four percentages replacement of silica fume (0%, 5%, 7.5%, 10%) and four percentages of sbr (0%, 5%, 10%, 15%) were investigated. a mathemati...