MEDICINE
Update
THE LATEST INTELLIGENCE
Tiny light-activated semiconductors could be used in the fight
against infections such as E. coli and salmonella
QUANTUM DOTS TO COMBAT
PROTECTION DRUG-RESISTANT BACTERIA
ENCOURAGES
RECKLESSNESS
Recent research suggests
safety kit may increase the
urge to take risks. Volunteers
at the University of Bath were
asked to inflate a virtual
balloon as much as possible
without bursting it. Some were
given a cycling helmet to wear
during the task; those that
did were more likely to fill the
balloon for longer.
OPACITY IS NO
GUIDE TO DENSITY
Data from NASA’s Cassini
mission shows that although
the opacity of Saturn’s B ring
varies, the amount of material
it contains is almost
uniform throughout.
VENUS FLYTRAPS
CAN COUNT
Researchers at Germany’s
Universität Würzburg mimicked
an insect landing on the
carnivorous plants and were
able to show that one touch
didn’t trigger the trap. Only
after a second touch would the
plant close its jaws around the
insect.
MOON LANDING
FAKE IN FOUR
YEARS
According to Dr David Grimes of
Oxford University, the number of
people required to fake the first
Moon landing would mean the
plot would have been exposed
within four years.
WHAT WE LEARNED
THIS MONTH
PHOTOS: GETTY, SCIENCE PHOTO LIBRARY, WIKIPEDIA
Salmonella bacteria (red)
can cause severe fever, vomiting
and diarrhoea
Quantum dots – tiny flecks of
semiconducting materials that react to light
- may solve the growing problem of drug-
resistant bacteria, according to researchers
at the University of Colorado Boulder.
Infections such as E. coli, staphylococcus
and salmonella, which are contracted by two
million people each year, are becoming
harder to treat. This is because the bacteria
that cause them are adapting to become
immune to antibiotic drugs.
The scientists, based at the Department of
Chemical and Biological Engineering, have
managed to create light-activated
therapeutic nanoparticles – quantum dots- that are able to destroy 92 per cent of drug-
resistant bacteria in experiments. The
quantum dots are made from the
semiconductor cadmium telluride – a
material that can conduct electricity under
certain conditions – and are 20,000 times
smaller than the width of a human hair. The
dots are activated by light, which triggers a
chemical reaction to break down the
bacteria. And as the quantum dots are so
small, they can be easily absorbed by the
invading bacteria.
“By shrinking these semiconductors
down to the nanoscale, we’re able to create
highly specific interactions within the cellular
environment that only target the infection,” said
Prashant Nagpal, a senior author of the study.
There have been attempts at using
nanoparticles made from metals, including
gold and silver, to fight drug-resistant
bacteria, but these were found to damage
the cells surrounding the bacteria
indiscriminately. The semiconductor
quantum dots, however, target the
bacteria specifically.
More importantly, the quantum dots
can be altered so that they remain effective
even if the bacteria adapts to this form
of treatment.
- that are able to destroy 92 per cent of drug-