Developments to Watch
Quicker Pulp, and That's No Fiction
Papermaking requires a lot of harsh and toxic chemicals to strip wood pulp of lignin, a tough polymer that makes trees strong and rigid. Wood chemist Vincent L. Chiang and a team of researchers from Michigan Technological University are trying to come up with a better solution: aspen trees that are bioengineered to produce less lignin. Their work was published in the August issue of Nature Biotechnology.
To create their trees, the scientists blocked the activity of a key lignin-producing molecule in the woody part of the tree. The result was a new strain of aspen with 45% less lignin. Surprisingly, engineered trees also grew 1.5 times faster and laid down more extensive root systems than their unmodified cousins. This may mean that more wood can be grown from less land using Chiang's trees, thus reducing the environmental impact of forestry. But aspens aren't normally processed to make paper, so Chiang's team is trying to repeat the result in two more popular pulpwood species, eucalyptus and pine. "It's a neat result that could make paper production easier and more economically viable," says Ronald R. Sederoff, a forestry expert at North Carolina State University.By Ellen LickingReturn to top
Sweet Relief for Victims of Earthquakes
As the death toll from Turkey's earthquake continues to climb, relief workers are busy caring for the survivors. Of these, up to 40% may be at risk for "crush syndrome," in which blood and other fluids accumulate in the muscles, resulting in substantial swelling. If left untreated, the condition can trigger kidney failure. A simple preventive measure--immediate and massive injections of fluid containing the synthetic sugar mannitol--is now being tried in Turkey. The new method was developed by Dr. Ori S. Better of the Technion-Israel Institute of Technology in Haifa.
Similar concoctions have been tried before, but two factors may give Better's formula an edge. Damaged muscles ooze toxins that, in large amounts, are poisonous to the kidneys. By injecting big doses of fluid into the body--up to 15 liters a day--Better claims he can preserve the body's normal fluid balance. He also has evidence that mannitol alleviates muscle swelling. After less than an hour's exposure to it, 15 patients all showed signs of decreased swelling. How mannitol works is a mystery--and the method has its own potential dangers: In large doses, the sugar can cause kidney failure. Still, Dr. James P. Knochel, an expert on muscle injury at Presbyterian Hospital of Dallas, says: "If this has the potential to save quake victims in Turkey, it is important to try it."By Ellen LickingReturn to top
Declaring a Germ War on Nuclear Waste
Cleaning up radioactive waste is a dirty job--but somebody, or something, has to do it. Now, researchers from the Energy Dept.'s Idaho National Engineering & Environmental Laboratory have devised a way to use the bacteria Thiobacillus thioxidans to clean up contaminated concrete walls and ceilings.
The researchers mixed millions of bacteria with sulfur and cellulose to create a fluorescent yellow gel thick enough to be slapped on walls and ceilings. At high temperatures and humidity, the bacteria feed on the sulfur and generate the corrosive byproduct sulfuric acid, which etches the concrete so that the contaminated layers flake away. When enough concrete has been loosened, the researchers kill off the bacteria by dropping the temperature and humidity. Then they vacuum up the contaminated material. Using this method, the researchers estimate they can remove up to half an inch of radioactive concrete a year.
The traditional cleanup method, called scabbling, requires workers to chip away layers of contaminated surface concrete until they reach a "clean" layer. But this process can expose laborers to damaging levels of radiation and generates a substantial amount of rubble and dust--all of which must be disposed of as radioactive waste. Because the microbial "goo" can be applied remotely, the risk to workers is minimized. And cleanup costs could be up to 10 times cheaper, since much less waste is generated. The researchers plan to field-test their microbial janitors at a closed nuclear reactor in Sellafield, England, this fall.By Ellen LickingReturn to top