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CLOCKWISE FROM TOP LEFT: NIGEL CATTLIN/ALAMY STOCK PHOTO; MIKKEL JUUL JENSEN/SCIENCE SOURCE; WYSS INSTITUTE AT HARVARD UNIVERSITYStuck on You
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TO PROTECT THEMSELVES
against predatory birds, some
slugs have evolved to produce
a defensive mucus that secures them
to virtually any surface. Strong, stretchy and effective even in
wet environments, the adhesive could be useful for surgeons
struggling to plug and patch patients’ slippery organs — if
only the substance could be efficiently manufactured.
Harvard University bioengineer Jianyu Li has now
mimicked this slug mucus in the lab, making synthetic glues
using extracts from shrimp shell and algae. “Our adhesives
are engineered to copy the essential biochemical and
microstructural characteristics of the mucus,” he says.
Like defensive mucus, Li’s concoctions can bond surfaces
chemically, physically and electrostatically. Initial tests,
reported July in Science, have demonstrated effective
adhesion to animal hearts and livers, as well as cartilage and
arteries. The slime that saves slugs’ lives could do the same
for humans. — JONATHON KEATSMathematicians
See Within
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JULES VERNE MIGHT BE
disappointed to learn that we still
can’t journey to the center of the
Earth. But those curious about what’s
down there — metal or monsters? — can
take heart from a mathematical proof
nearly four decades in the making.
The proof, posted online in February,
demonstrates that an object’s insides
can be mapped exactly without
cutting it open. All you need to know
is how quickly waves travel between
every possible pair of points on the
object’s surface.
Strictly speaking, the proof applies only
to certain mathematically perfect objects.
“The Earth is far from mathematical
idealization,” says Stanford University’s
András Vasy, one of three mathematicians
behind the proof. Still, he hopes their
work will lead to better tools for geology,
which already investigates Earth’s interior
by studying seismic waves, and medical
imaging, which infers the internal details
of bodies from electromagnetic waves
like X-rays. — DEVIN POWELLBioengineers inspired by slug secretions (top) have created an adhesive
that sticks to even wet biological tissues (above).