Laureates unveil revolutionary Teflon hybrid
This year’s Nobel physics laureates have created what promises to be a new “wonder material” by combining the remarkable properties of graphene, for which they won the prize, with Teflon.
Andre Geim and Kostya Novoselov of Manchester University worked with an international research team to modify graphene, the world’s thinnest material, consisting of carbon sheets just one atom thick, by making it react with fluorine.
Their resulting material, fluorographene, retains the astonishing strength and lightness of the original graphene – first made by the two Russian-born scientists in 2004 – but has different electrical and physical properties that could be extremely useful for many applications.
Just as graphene is two-dimensional graphite, fluorographene is essentially a 2D version of Teflon, the carbon fluoride polymer that has transformed the plastics industry since its creation 70 years ago by DuPont, the US chemicals giant.
The molecular structure of fluorographene is a flat hexagonal honeycomb of carbon atoms, with a fluorine atom attached to each carbon. The added fluorine atoms transform graphene from an excellent electrical conductor into a semiconductor, which could be extremely useful for electronic applications.
The Manchester researchers – and their collaborators in Russia, China, Poland and the Netherlands – published details of fluorographene in the scientific journal Small.
The compound is mechanically strong and chemically and thermally stable. “It is essentially a perfect one-molecule-thick crystal,” says Rahul Nair, who led the fluorographene research project in Geim’s Manchester laboratory. “We plan to use fluorographene [in electronics] as an ultra-thin tunnel barrier for the development of light-emitting devices and diodes.
“More mundane uses can be everywhere Teflon is currently used, as an ultra-thin protective coating, or as a filler for composite materials if one needs to retain the mechanical strength of graphene but avoid any electrical conductivity or optical opacity of a composite,” Nair adds.
According to Geim: “The mix of the incredible properties of graphene and Teflon is so inviting that you do not need to stretch your imagination to think of applications for the two-dimensional Teflon. The challenge is to exploit this uniqueness.”
The Manchester researchers plan next to make proof-of-concept devices and demonstrate various applications of fluorographene. They have patented the material and could make a lot of money if it lives up to their expectations.
New world, same old flu
The virus spread rapidly around the world from Asia to Europe and Africa; resisted all human efforts to limit its spread or effect; and caused disproportionate death among pregnant women and children, writes Andrew Jack.
It could have been almost any of the flu pandemics experienced globally in recent decades, but in fact it was the first known example recorded in history – from 1510.
A paper in the journal Clinical Infectious Diseases by David Morens and colleagues at the US National Institutes of Health describes how Christmas trees, pocket watches and Benedictine liquor were not the only phenomena to be spread with the opening of trade routes.
In July 1510 – not that long after Columbus’s arrival in the new world – reports emerged in many countries of a “gasping oppression”, with cough, fever and a sensation of constriction in the heart and lungs. It disrupted an assembly of bishops, prelates and professors convened by Louis XII, and caused the eight-year-old future Pope Gregory XIII to become dangerously ill, although he fully recovered.
The disease spread around the world via ships – entering Europe through Italy and Sicily – and many of the deaths came through excessive blood-letting. But in its impact, the “medieval” flu was little different from last year’s Mexican flu.
Despite the authors’ catalogue of subsequent improvements in scientific understanding of flu, the development of surveillance systems, vaccines and drugs, efforts to predict or restrain its spread remain limited.
“We are probably no better able today to anticipate and prevent the emergence of pandemic influenza than five centuries ago,” they conclude, before arguing more optimistically that progress “should one day lead to additional significant advances in influenza prevention, control and treatment”.
A nose for food
People with a higher body-mass index seem to be more susceptible to the smell of food, claims a University of Portsmouth study. Overweight people were better at smelling food than their slimmer counterparts
How the dragon got its snap
A powerful combination of computer modelling and experimental genetics is showing how the intricate shapes of organs found in nature are produced by a small number of interacting genes.
“Looking at the complex, beautiful and finely tuned shapes produced by nature, people have often wondered how they came about,” says Enrico Coen, who is leading a joint research project at the John Innes Centre and University of East Anglia. “We are beginning to understand the basic genetic and chemical cues that nature uses to make them.”
The Norwich scientists are using the snapdragon as a model. In its flowers, two upper and three lower petals come precisely together to form a tube with a hinge. When a bee lands on the lower petals the hinge opens up the flower, allowing access to nectar and pollen.
Four main genes control the shape of the petals. By switching these growth genes on and off and tracking how the changes affect the flower’s development, the researchers got pointers as to how genes control the overall shape.
A key finding of the study, published in the journal PLoS Biology, was that the genes control both how quickly different regions of the petal grow and their orientations of growth. Each cell has a chemical compass that allows it to get its bearings within the tissue, providing the information needed to grow more in some directions than others.
Computer simulations show how these principles allow very complex biological shapes to generate themselves.
New risk of antibiotic drug resistance
In a new warning about the dangers of excessive use of antibiotics, Swedish scientists have found that even short courses of antibiotics can leave normal gut bacteria harbouring drug-resistance genes for up to two years after treatment.
In the latest issue of the journal Microbiology, the researchers say that this reservoir increases the chances of resistance genes being passed on to harmful bacteria – suggesting that the long-term effects of antibiotic therapy are more significant than had previously been thought.
Antibiotics prescribed to treat harmful infections have an impact on the normal microbial flora of the human gut. They can alter the balance of microbial populations and allow bacteria that are naturally resistant to the antibiotic to flourish.
Doctors frequently assume that the impact of antibiotics on the normal gut flora is short-term, with any disturbances being restored several weeks after treatment. However, the Swedish research shows the unjustified complacency of this view.
“The long-term presence of resistance genes in human gut bacteria dramatically increases the probability of them being transferred to and exploited by harmful bacteria that pass through the gut,” says Cecilia Jernberg of the Swedish Institute for Infectious Disease Control. “This could reduce the success of future antibiotic treatments and potentially lead to new strains of antibiotic-resistant bacteria.”
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