Molecules/Matter & Energy

How leeches are able to swell tenfold, plus not-so-super solids, new natural toxins and more in this week's news

Not so super after all? A team of researchers is challenging the claim that scientists have spotted a new state of matter. First reported in 2004, “supersolidity” would occur in solid helium at extremely low temperatures, allowing atoms to slide through one another ( SN: 9/11/10, p. 22 ). In the May 13 Science , Séamus Davis of Cornell and his colleagues report new work on frozen helium. They say they see a bizarre type of crystallization that could explain the helium’s behavior without invoking supersolidity. —
Alexandra Witze Garden-variety poisons Move over Monsanto, Bayer and Syngenta. A new study finds that some plants produce chemicals that “are as toxic as commonly used herbicides and biocides.” Scandinavian researchers acquired cyclotides, unusual circular poisons made by coffee plants, violets and members of the melon family (to name a few), and applied them to everything from lettuce and algae to soil bacteria. The particular compounds the researchers selected — typical of cyclotides produced by the African plant Oldenlandia affinis and the English violet — “were toxic to all test organisms,” the scientists report in the May Environmental Toxicology and Chemistry . These data point to plants that could harm nearby crops by releasing the compounds into soil. — Janet Raloff Quick infection test Researchers are closer to a quick and easy test for bacterial urinary tract infections. Standard techniques for detecting UTIs, the second most common infection in the U.S., involve growing collected bacteria in a dish, which can take up to three days. Now, using a bit of
E. coli genetic material as a self-seeking flashlight, Stanford researchers detected the bacterium’s genetic material in urine samples and quantified the infection load in less than 15 minutes. The researchers would like to make the test even more sensitive and tune it to other kinds of bacteria, but preliminary work, to appear in Analytical Chemistry , suggests rapid diagnostic tests aren’t far off. — Rachel Ehrenberg Bloodsucker’s body booster The multitasking compound that plays a role in depression, milk production, bone health and digestion also helps bloodsucking leeches swell to more than 10 times their size when eating. Serotonin seems to make muscles of the medicinal leech, Hirudo verbena , resistant to overstretching, while also boosting contractibility, scientists from Wellesley College in Massachusetts have discovered. But there isn’t much potential for human therapies — with or without serotonin, leech muscles are arranged differently than those of animals with bones, aiding in leeches’ remarkable enlargement, the team notes in the May 11 Biology Letters . — Rachel Ehrenberg

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