When Evan T. Keller and his Ann Arbor team compared tissues from aggressive prostate tumors with samples from tumors that hadn't spread, they found much lower levels of a protein called RKIP in the metastasized tissue. They then injected the gene associated with RKIP into mice engineered to develop human prostate cancer. As the team reports in the June 18 Journal of the National Cancer Institute, the injected mice developed 70% fewer metastases than an untreated group.
RKIP is not involved in the growth of the tumor, only its spread. That could still be a lifesaver, though -- and perhaps not just for patients with prostate cancer. Keller says the same mechanism may exist in other cancers, and his team is now looking for the same gene differences in breast, colon, and brain cancers. Spider silk has long been admired for its great strength. Now, researchers at the University of California at Riverside are putting to use its fineness and consistency, too. They are utilizing spider thread as a template for making hollow optical fibers, aiming to create tubes just 2 nanometers wide, or 50,000 times thinner than a human hair.
Currently, most optical fibers are made of solid glass, with pulses of light traveling through the core. If the glass core were replaced by air, which impedes light much less than glass, signals could zip along faster and farther. A team led by chemical engineer Yushan Yan is developing a cheap and simple process for making hollow fibers: coat spider silk with liquid crystalline silica. After the silica shell solidifies, the strand is baked to burn out the spider silk, leaving a thin hollow tube. If engineers can find a way to obtain enough silk and solve some production kinks, hollow fibers could provide a major performance boost to the telecom industry -- all thanks to nature's web weavers. Big commercial fuel cells are already turning hydrogen into electricity in factories, office buildings, and power plants around the country. Most are fed by so-called reformers -- mini chemical plants that convert natural gas into hydrogen at around 2,000F. Such infernal temperatures are O.K. in industrial settings, but it's hard to imagine those reformers in homes.
Scientists at Georgia Institute of Technology have found a way to cool things down to as low as 600F -- "closer to the heat in your kitchen oven," says Zhong Lin Wang, a professor of materials science. It's done with certain oxides of rare-earth elements such as cerium. When doped with iron, the oxides efficiently transform methane into hydrogen, Wang's team reports in the March issue of Advanced Materials.
What's more, the Georgia Tech materials are self-renewing and work continuously. The oxides are recharged by exposing them to water vapor, from which they absorb the oxygen that was used in the conversion process. And despite their name, Wang's rare-earth oxides are plentiful, so they should be cheaper than the catalysts used in high-temperature units. In time, he hopes to slash the heat needed to levels so low that solar power could drive the reformer. Meanwhile, fuel-cell makers are lining up to fund the project. -- It's dental dogma that adult human teeth can't grow or repair themselves. But that may change. A research collaboration between the National Institute of Standards & Technology and the American Dental Assn. has developed a compound that promotes tooth regrowth. Laboratory tests of the material -- an amorphous calcium phosphate encapsulated in polymers -- have been so successful that plans for clinical trials are now being laid, and several companies are negotiating for commercial licenses.
-- Irritated that "we still live and work in fairly dumb buildings," University of Illinois electrical engineer Chang Liu wants to bring construction materials into the electronics age. The first result of his Urbana-Champaign team's work is a "smart" brick. Buried in it are sensors and a radio, turning the brick into a sort of combination seismograph and fire-alarm system. It could report on earthquake damage or structural problems and warn firefighters of hot spots in buildings where fires are blazing on some floors. The technology could also be embedded in concrete blocks and laminated-wood beams.