molecules to evolve in the test tube. With the discovery of catalytic RNA, and advances in nucleic acid amplification techniques such as the polymerase chain reaction, it became possible to construct laboratory systems that allow the Darwinian evolution of functional RNA (and later DNA) molecules. This is not evolution based on natural selection, but rather directed evolution based on selection...

Average stress during shear bond testing, and deformation behaviour during nano-indentation testing were calculated for the bonding area as a bonding site for copolymerization with resin composite in dentine bonding systems. First average stress was calculated in the bonding area between bovine dentine and composite resin. Secondly, the plastic deformation zone size was calculated using an elas...

Polymer modified concrete (PMC) consists of Portland cement concrete with a polymer modifier. Its advantages are proper bonding strength to substrate concrete, high tensile and flexural strength and low amount of shrinkage and permeability. Using PMC overlays can be considered as a method for preservation of damaged concrete structures due to their suitable performance and durability. In this r...

T he increasing number of older people and decrease in the birth rate means that the future is going to be a very different place in terms of population profile than today. And our response to the future older citizen will be different too. For one thing, people of today's generation, who have lived through the post-war years, are likely to be better informed, educated and wealthier than previo...