Plasma needle for dentists

No one likes the dentist’s drill, a fact that has inspired scientists to come up with an alternative - a needle with a flaming plasma tip.

While that may sound like an even less welcoming oral intrusion, the needle is cold to the touch and can painlessly kill bacteria without harming other living cells.

As well as dentistry the needle could also have other uses such as cutting away cancerous tissue, say the inventor Eva Stoffels-Adamowicz, a physicist from Eindhoven University of Technology in the Netherlands, in a story from New Scientist.

Plasma is a highly ionised gas, sometimes known as the fourth state of matter. Ninety-nine per cent of all matter in the universe is in a plasma state with lightning, neon lights and fire being natural examples of plasma on Earth.

Ms Stoffels-Adamowicz and her team came up with the idea for the needle after working with low-pressure plasmas which are created in a vacuum.

But for the plasma to be used on people it had to be able to work in air, so the scientists housed a 50mm long wire in a quartz tube filled with gas. A voltage passing through the needle produced a small plasma spark at the tip, described as “like a children’s sparkler”.

By flushing helium - which helps plasma to form from air efficiently - and gas and air into the tube, the team generated a nitric oxide plasma. Because the body uses nitric oxide to fight infection and inflammation, the researchers discovered that when the plasma is applied in short bursts using small amounts of energy it could kill bacteria while leaving human cells unharmed.

In addition, because nitric oxide is also used in cell messaging, it can be used to trigger cell death. When the scientists used higher energy doses of plasma for longer periods, the needle could also be used cauterise living tissue while leaving surrounding tissues unaffected. The team says the technology could be used for removing tumours or skin cancers without cutting.

Looking further ahead, Ms Stoffels-Adamowicz’s team are working on how to generate a plasma that could be sent down blood vessels via a catheter in order to clear unblocked arteries.

Plastics based on sugar

The soaring price of petrol has sparked a race to develop alternative transport fuels to petroleum from plant matter, with both biodiesel and gasoline containing ethanol beginning to make an impact on the market.

But what about the millions of tons of chemical intermediates - compounds which are the raw material for many modern chemicals from plastics to drugs - which are largely based on petrol or natural gas?

A group of scientists from the University of Wisconsin-Madison have applied for a patent for their new method of creating a chemical intermediate called HMF (hydroxymethylfurfural) from fructose, the sugar found in fruit. HMF can be fairly simply converted into plastics or diesel-fuel but is seldom used because it is costly to make.

The new method combines the right balance of chemistry, pressure, temperature and reactor design to produce HMF from fructose more efficiently than before, raising output and making the chemical intermediate easier to extract.

A catalyst coverts the fructose into HMF. The HMF then moves to a solvent that carries it to a separate location where the HMF is extracted.

The method when perfected could allow countries to use agriculturally-produced biomass as the building block for many of its chemical needs, so that they are be less reliant on expensive oil imports, often coming from parts of the world marked by instability. Also, the method is greener because, unlike fossil, using biomass does not introduce additional carbon dioxide into the atmosphere and less harmful ingredients are used in the process of making industrial chemicals.

Talking camera helps

Described as “the camera that talks”, a new handheld device that reads print aloud will allow visually impaired people to “read” simple text formats such as menus and recipes.

The reader, which has been developed by Ray Kurzweil - a pioneer of text-into-audio technology - in partnership with the National Federation of the Blind in the US, combines a digital camera and personal data assistant with proprietary software.

Resembles a multi-bodied camera slightly larger than the human hand, the device works by positioning the reader over print and taking a picture. Within seconds, the printed message is read out aloud.

The device is good news for the 10m blind and visually-impaired people in the US, a figure that is expected to double over the next 30 years as baby boomers grow old.

Mr Kurzeil invented the first reading machine about thirty years ago but it was the size of a washing machine. The breakthrough with the new reader, which has been tested by approximately 500 visually-impaired people, is the gadget’s portability.

He hopes that in future the technology will allow for the deciphering of more complex formats and eventually identifying objects and people.

The Kurzweil-National Federation of the Blind reader is set to be launched this year with a price tag of about $3,500.

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