21 мая 2002 г.
|
Новости науки и техники в "Scientific American"
21 мая 2002 г. |
ANTHRAX TO THE RESCUE?In the last two decades, researchers have discovered how the anthrax toxin forms a pore that provides an entryway for two other toxin proteins to get into a cell's inner recesses and wreak havoc. That breaking-and-entering strategy has not gone unnoticed by scientists seeking new ways to deliver vaccines into cells. And the lethality of one of the proteins has attracted the attention of investigators who have shown an interest in marshalling its killing power to combat tumors.SQUIGGLES IN SANDSTONE MAY DOUBLE AGE OF EARLIEST MULTICELLULAR ANIMALSTo the untrained eye, they're not much to look at - a smattering of tiny squiggles decorating slabs of sandstone. But don't let their modest appearance fool you: these may be the earliest traces of multicelluar animals, or metazoans, yet found - more than twice as old as the roughly 600-million-year-old remains considered by most paleontologists to be the first uncontroversial metazoans.SIMULATION SHEDS LIGHT ON FORMATION OF FIRST STAR CLUSTERSThe first star clusters in the universe may have arisen from cold gas clouds nearly 1,000 times more massive than any observed in our galaxy, according to new computer simulations. The results also suggest that globular star clusters - the oldest star clusters in the universe - were formed in a manner analogous to that of the relatively recent formation of clusters in the Milky Way.SINGLE MOLECULE CAN CONVERT LIGHT INTO WORKScientists have designed a single-molecule device capable of converting light into mechanical energy, according to a new report. The development could aid efforts to create motors or switches for future molecular machines.NEW DRUG HOLDS PROMISE FOR COMBATING ALZHEIMER'SA key feature of a number of diseases - most noticeably Alzheimer's - is the presence of so-called amyloid deposits comprised of insoluble clumps of proteins that kill surrounding cells. A naturally occurring protein present in the bloodstream known as serum amyloid P component (SAP) aids these plaques in destroying healthy tissue by binding to the amyloid fibers and preventing the body from breaking them down. New research indicates that a drug designed to thwart the action of SAP holds promise for treating human amyloid diseases.ASK THE EXPERT : HOW CAN GRAPHITE AND DIAMOND BE SO DIFFERENT IF THEY ARE BOTH COMPOSED OF PURE CARBON?Miriam Rossi, a professor of chemistry at Vassar College, provides an explanation.