Breaks in DNA happen all the time, whether due to radiation or the error-prone process of duplicating DNA for cell division. If those breaks are repaired incorrectly, a cell can become cancerous. Now, using a plate of glass and a tiny magnetic bead, scientists in Holland have watched a repair process called homologous recombination. Cees Dekker of the Delft University of Technology and his colleagues suspended individual strands of DNA between the glass and the bead. Also present was an enzyme that broke the DNA, along with another enzyme, RecA (shown here as transparent blobs). The researcher...
Credit: TU Delft/Thijn van der Heijden and Frank van Heesch

Researchers in Japan have developed a heat-treated steel (TF, at right) that’s tougher at both high and low temperatures than conventional steel (QT, left). At a brisk -100 degrees Celsius, the heated steel absorbed more than 10 times the energy from an impact test before breaking than regular steel. Unlike the alloyed steels used for low-temperature applications, the tougher new steel doesn’t require that any other elements be added to it, and so would be much cheaper.
Credit: AAAS/Science