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Issue no. 6, 2011
Published: Feb 11, 2011 |
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 Team makes nanosheet breakthrough | | Nanowire processor signals route to ever-smaller chips | | Hong Kong researchers store data in bacteria | | Toward a fast, simple test for detecting cholera | | X-ray device zaps deep cancers in 15 minutes | | Paper archives reveal pollution's history | | World's shift from analogue to digital is nearly complete | | Ninetendo's Wii used to help measure sprinter's speed |
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| Team makes nanosheet breakthrough |
Splitting materials into sheets just one atom thick could lead to new
electronic and energy storage technologies. An international team of
researchers say they have invented a versatile way to create one atom
thick 'nanosheets' from a range of layered materials, using ultrasonic
pulses and common solvents. The new method is simple, cheap, fast, and
could be scaled up to work on an industrial scale, the scientists say.
The research adds to previous studies by two Russian-born scientists,
who last year won the Nobel Prize for physics for their work on
graphene, a form of carbon that is just one atom thick and yet 100 times
stronger than steel.
The new materials the team had created - which include boron nitride,
molybdenum disulfide, and bismuth telluride - have chemical and
electronic properties that make them suitable for use in new electronic
devices, super-strong composite materials and energy generation and
storage. The materials could for example be made into devices that
generate electricity from waste heat, according to the scientists.
These new materials could also be used in next generation batteries
known as 'supercapacitors', which can deliver energy thousands of times
faster than standard batteries and could vastly improve technologies
such as electric cars. |
| ABC News / Reuters / Science
Feb 04, 2011 |
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| Nanowire processor signals route to ever-smaller chips |
Engineers at Harvard University have developed a computer chip made of
tiny 'nanowires' whose computing functions can be changed by applying
small electric currents. These 'programmable logic tiles' may represent
the building blocks of a new generation of ever-smaller computers.
Instead of etching chips down from chunks of material, the
nanoprocessors can be built up from minuscule parts.
The team has spent the last few years developing the nanowires - each
made of a core of the element germanium and sheathed in a silicon shell.
The latest report is a demonstration that the wires can be made reliably
enough to enter the world of computing. Small circuits made of nanowires
have been assembled before, but the latest work is unique in the sheer
complexity of the resulting circuit, along with the fact that the tiles
can be 'cascaded' to yield far more complex circuits.
The group's prototype design is based on a mesh of the nanowires. It
contains nearly 500 of them in a 1mm-square area, criss-crossed with
normal metal wires. Together with a whisker-thin stack of semiconductor
materials laid on top, this mesh acts as a collection of transistors.
Passing an electric current through the normal wires can change the
so-called 'threshold voltages' of each transistor; the whole ensemble is
in this way completely programmable. The team demonstrated the
changeable nature of their chip by re-programming it to do a number of
mathematical and logical functions. |
| BBC News / Nature
Feb 10, 2011 |
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| Hong Kong researchers store data in bacteria |
A group of students at Hong Kong's Chinese University are making strides
towards storing such vast amounts of information in an unexpected home:
the E.coli bacterium better known as a source of food poisoning. The
group says that one gram of bacteria could store the same amount of
information as 450 2,000-gigabyte hard disks.
In 2007, a team at Japan's Keio University said they had successfully
encoded the equation that represents Einstein's theory of relativity,
E=MC2, in the DNA of a common soil bacterium. They pointed out that
because bacteria constantly reproduce, a group of the single-celled
organisms could store a piece of information for thousands of years.
But the Hong Kong researchers have leapt beyond this early step,
developing methods to store more complex data. The group has developed a
method of compressing data, splitting it into chunks and distributing it
among different bacterial cells, which helps to overcome limits on
storage capacity. They are also able to 'map' the DNA so information can
be easily located. This opens up the way to storing not only text, but
images, music, and even video within cells.
They have also developed a three-tier security fence to encode the data.
The team have even coined a word for this field - biocryptography - and
the encoding mechanism contains built-in checks to ensure that mutations
in some bacterial cells do not corrupt the data as a whole. |
| Expatica / AFP
Feb 07, 2011 |
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| Toward a fast, simple test for detecting cholera |
With cholera on the rampage in almost 40 countries, scientists are
reporting the development of a key advance that could provide a fast,
simple test to detect the toxin that causes the disease. Cholera affects
more than 200,000 people annually, mainly in developing countries, and
causes about 5,000 deaths every year.
Cholera is an intestinal infection from food or water contaminated with
the bacterium Vibrio cholerae. It produces a toxin that can cause severe
diarrhoea, which can lead to rapid dehydration and death. Prompt
treatment thus is essential, and yet existing tests to diagnose cholera
are time-consuming, expensive, and require the use of complex equipment.
The scientists describe a key advance toward a better, faster test. The
new method uses specially prepared nanoparticles of iron oxide coated
with a type of sugar called dextran. To achieve this, they looked for
specific characteristics of the cholera toxin receptor (GM1) found on
cells' surface in the victim's gut, and then they introduced these
features to their nanoparticles.
When the magnetic nanoparticles are added to water, blood, or other
fluids to be tested, the cholera toxin binds to the nanoparticles in a
way that can be easily detected by instruments. The test hardware can be
turned into portable gear that health care workers could use in the
field, the scientists say. The approach also shows promise for treating
cholera intoxication. |
| PhysOrg / Bioconjugate Chemistry
Feb 09, 2011 |
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| X-ray device zaps deep cancers in 15 minutes |
A super-accurate radiotherapy device that can target tumours deep inside
the body is now bringing new hope to UK cancer patients.
Radiosurgery is a non-invasive cancer treatment in which targeted
radiation beams are used to destroy or shrink tumours. But the Novalis
Tx device tailors these beams to match the exact shape, size and
position of a tumour in the body. This means that a more intense beam
can be used without causing damage to surrounding tissue. The device can
also manoeuvre the beams to reach tumours deep inside the body, such as
in the spinal cord, which were previously inaccessible.
The system uses X-ray images of a tumour to monitor its position, and
can even adapt when growths - such as those in the lungs - move as the
patient breathes. It responds by only zapping the tumour when it returns
to its original position after each breath. Patients who would normally
have to spend months recovering from complicated open surgery to remove
brain tumours can now be treated in one session and return to normal
life the following day. In some cases, cancer patients can be treated in
just fifteen minutes.
The machine was launched at the Clatterbridge Cancer Centre in
Liverpool, UK, this week and is due to be set up in medical centres in
Manchester and Edinburgh later this year. |
| New Scientist
Feb 10, 2011 |
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| Paper archives reveal pollution's history |
Some of the history preserved in old tomes and journals may be hiding in
between the lines of print. A scientist at the Weizmann Institute in
Israel has found that the paper in such collections contains a record of
atmospheric conditions at the time the trees that went into making it
were growing.
By analysing the carbon isotopes in bits of paper clipped from old
magazines, Dan Yakir has traced the rising effects of atmospheric
pollution from burning fossil fuel going back to beginnings of the
industrial revolution. Yakir removed small samples from the margins of
successive volumes of journals going back more than 100 years for
analysis. The analysis was based on a finding that the proportion of
carbon 13 (13C) to its lighter counterpart carbon 12 (12C) could provide
information on the CO2 added to the atmosphere from burning fossil fuel.
Plants prefer to use CO2 made with the more common version of carbon,
12C, than the heavier 13C. Plant biomass from millions of years ago was
transformed into reservoirs of oil, gas and coal, and so these are
naturally low in 13C, as well. When mankind started to burn those
reservoirs following the industrial revolution, they began returning the
13C-poor CO2 to the atmosphere. Now the atmospheric 13C content has
become increasingly diluted, and this is reflected in the carbon ratios
in the trees milled for pulp and paper.
Yakir's work shows that this continuing dilution is, indeed, clearly
recorded in the archival paper and it demonstrates the increasing
intensity of our fossil fuel burning in the past 150 years. |
| PhysOrg / Weizmann Institute of Science
Feb 08, 2011 |
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| World's shift from analogue to digital is nearly complete |
The tipping point came in 2002 - that was when the world began storing
more information in digital than in analogue format, or so estimate the
researchers from the University of Southern California who recently
completed an inventory of the world's technological capacity.
As humanity races toward completing its shift from analogue to digital
data communication and storage, scientists can look back at how fast the
transition has been. In 2000, three-quarters of the world's information
was still in analogue form. By 2007, 94% had been preserved digitally.
The team surveyed 60 categories of analogue and digital technologies
during the period from 1986 to 2007, and the results reflect the near
complete transition from the analogue to the digital age. Over the course
of their research, they started to home in on the tipping point. The
year when digital information became dominant was 2002, they estimated.
The researchers also estimated that the world's technological capacity
to compute information via application-specific devices such as
electronics' microcontrollers or graphic processors roughly doubled
every 14 months over the past decades. The capacity of general-purpose
computers such as PCs and mobile phones has doubled every 18 months. |
| MSNBC / Science
Feb 10, 2011 |
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| Ninetendo's Wii used to help measure sprinter's speed |
We already knew it can be used to train surgeons, assist the military,
and rehabilitate stroke sufferers. Now researchers have discovered that
the Nintendo Wii can calculate running speed with impressive accuracy.
Ross Clark at the University of Melbourne, Australia uses a bastardised
Wii Remote hand controller to measure the speed of professional rugby
players. He found that it is more accurate than conventional stop
watches, easy to travel with, and much cheaper than the commercial
timing light systems, which can run up to USD 250,000.
Wii hand controllers have a small infrared camera that detects multiple
light sources and transfers their position via Bluetooth onto a Nintendo
Wii console, or computer. Clark placed two infrared LED light sources at
the beginning and end of a running track, and pointed a Wii hand
controller at the lights. Once someone runs past the light source it
'breaks the beam' - which is detected by the controller. Calculating the
time taken to break the first and then second beam reveals sprinter's
speed, says Clark. The whole system can fit into a travel bag, and costs
under USD 100. |
| New Scientist / Journal of Science and Medicine in Sport
Feb 11, 2011 |
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