Magnets without metals
Magnetism is a rare property in matter, and until recently had only been seen in metals, or materials that contained metal. Now a new metal-free magnetic polymer more than 100 times as magnetic as any before it has been developed by researchers at the University of Nebraska. Andrzej Rajca and collaborators strung together molecular units, each made of 14 benzene molecules, to make the novel plastic. Iron still outperforms it by about a factor of 20, but progress with materials like this could lead to new technologies in which lightweight polymers take the place of iron and steel in generators and motors.
ref.: Science, Nov. 16, 2001.
Hope for Crohn's patients
Crohn's disease, which tortures patients with excruciating gut pains, soon may be treatable by homing in on a critical protein. Cox Terhorst and colleagues at Beth Israel Deaconess Medical Center have found that mice with intestinal inflammation that mimics that of Crohn's disease responded well to a treatment with antibodies to migration inhibitory factor, or MIH. People with Crohn's disease tend to have elevated blood levels of MIH, suggesting that this work may point to treatments that will work in humans.
ref.: Nature Immunology, November 2001.
Antibiotics from sweat
German scientists have shown that human sweat contains a natural germ-killer. Claus Garbe and his colleagues at the University of Tuebingen were studying skin cancer when they found a gene in sweat glands that is not present in other skin cells. The protein coded for by this gene is partially broken down by an as-yet-unknown enzyme, producing a peptide that has been dubbed ''dermicidin.'' Dermicidin kills at least four types of bacteria and one type of fungus, and has the unusual property of remaining active even in the salty and acidic environment of sweat where most other antimicrobial peptides fail. Its future as a therapeutic agent is still an open question.
ref.: Science News, Nov. 10, 2001.
The first star
The first cosmic structure to form after the big bang may have been a giant star. Tom Abel and his colleagues at the Harvard Smithsonian Center for Astrophysics have been studying the sorts of fluctuations in the density of matter in the early universe that could have seeded the formation of stars and galaxies. Their calculations suggest that everything started off with a single big star surrounded by a gas cloud, with nothing else forming until that star exploded in a supernova. In other words, it looks like the big bang was followed by a smaller bang before the ball really got rolling.
ref.: Science, Online Nov. 15, 2001.
The fastest X-ray
The shortest X-ray pulses ever have been made at the University of Vienna in Austria. Ferenc Krausz and collaborators used ultrashort pulses of visible light into neon gas to pull electrons away from the atoms. The electrons then crash back, releasing a burst of X-rays that lasts less than a millionth of a billionth of a second. Applications of this sort of super-fast X-ray flash are expected to be numerous, ranging from studies of chemical and biological processes with unprecedented time resolutions to fundamental questions in quantum mechanics such as whether scientists can watch a quantum jump in an atom as it happens.
ref.: Nature, Nov. 29, 2001.
Dopamine to blame?
Parkinson's disease arises when neurons that pump out dopamine die, leaving patients with muscle tremors and stiffness. Now Peter Lansbury of Harvard Medical School in Boston and his colleagues have made the remarkable suggestion that dopamine itself may play a contributory role in the deaths of these very neurons. This surprising result has scientists thinking hard about what is really understood about the mechanisms that underlie the disease. Therapies for Parkinson's disease normally aim to increase dopamine levels, and the specter now arises that such treatments may contribute to the damage.
ref.: Science, Nov. 9, 2001.
Like a dolphin
A new strategy to stop fouling of ship's hulls is based on making them more like dolphins. Christof Baum and colleagues at the Alfred Wegener Institute for Polar and Machine Research in Bremerhaven, Germany, have shown that dolphins owe their ease of swimming and resistance to barnacles to a sandpapery skin texture along with a gel that oozes out of their pores. They have recently patented a varnish that lets ships emulate dolphin skin, which could replace the costly and environmentally damaging antifouling agents like tributyl tin that are currently in use.
ref.: Ottawa Citizen, Nov. 25, 2001.
S tephen Reucroft and John Swain are experimental particle physicists who teach at Northeastern University.
