Scientists make nanosheets with high-tech potential

A novel way of splitting materials into sheets just one atom thick could lead to new electronic and energy storage technologies, scientists said Thursday.

An international team of researchers said they had invented a versatile way to create one atom thick "nanosheets" from a range of layered materials, similar to the graphite used in pencils, 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 said in a report of their work published in the journal Science.

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.

"Because of its extraordinary electronic properties graphene has been getting all the attention...as physicists hope that it might one day compete with silicon in electronics," said Valeria Nicolosi, of Britain's Oxford University, who led the study with Jonathan Coleman of Ireland's Trinity College Dublin.

"But in fact there are hundreds of other layered materials that could enable us to create powerful new technologies."

Coleman said the new materials this team had created -- which include Boron Nitride, Molybdenum disulfide, and Bismuth telluride -- have chemical and electronic properties which make them suitable for use in new electronic devices, super-strong composite materials and energy generation and storage.

"Of the many possible applications of these new nanosheets, perhaps the most important are as thermoelectric materials," he said in a statement about the findings.

He said the materials could for example be made into devices that generate electricity from waste heat lost from places like gas, oil or coal-fired power plants, which lose between 50 and 70 percent of the energy they produce in waste heat.

"The development of efficient thermoelectric devices would allow some of this waste heat to be recycled cheaply and easily," Coleman said.

Scientists have been trying for decades to create nanosheets of these kind of materials, because arranging them in atom-thick layers enables their unusual electronic and thermoelectric properties to be unlocked, the researchers explained.

But all previous methods were very time consuming and laborious, and the resulting materials were fragile and not suitable for most applications.

"Our new method offers low-costs, a very high yield and a very large throughput -- within a couple of hours, and with just 1 milligram of material, billions and billions of one-atom-thick graphene-like nanosheets can be made at the same time from a wide variety of exotic layered materials," said Nicolosi.

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.

Source:http://www.reuters.com/article/2011/02/03/us-science-nanosheets-idUSTRE7127EB20110203?feedType=RSS&feedName=scienceNews&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+reuters/scienceNews+(News+/+US+/+Science)

Laser blasts sunlight protein into view

(Image: Thomas White/DESY)

Meet photosystem I, a plant protein that converts sunlight into energy during photosynthesis, in all its crystalline glory.

To create this image, researchers led by Henry Chapman of the Centre for Free-Electron Laser Science at the German national laboratory DESY sprayed 15,000 nanocrystals of the protein into the path of the Linac Coherent Light Source, an X-ray laser at the SLAC National Accelerator Laboratory in Menlo Park, California.

Powerful laser pulses vaporised the nanocrystals almost instantly, but not before the crystals had scattered X-rays, producing diffraction patterns that could be combined to render the crystal's detailed structure in three dimensions.

The ability to glean structural data from such tiny crystals could allow many more proteins to be understood. Other methods of elucidating structure require larger crystals, which, for some proteins, can be difficult or impossible to prepare.

Journal reference: Nature, DOI:10.1038/nature09750

Caffeinated Gene Therapy

Many people in society simply cannot function without a daily dose of caffeine. It is so prevalent in many diets. From coffee, to tea, to soft drinks, it has become a staple on par with corn or wheat, or even water. Of course caffeine is not necessary to survive, but it is sure good at keeping our eyes open. However, according to a new study from researchers at the University of Texas, caffeine does more than just keep us awake. It also energizes cells into producing more viruses used for gene therapy.

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Caffeine is the world's most widely consumed psychoactive substances, and amazingly, is completely legal and unregulated. It is found naturally in many plant species such as coffee, tea, and cocoa beans. Plants generate it because it paralyzes and kills certain insects which feed upon them. Therefore, it is the only stimulate we consume that is also a pesticide.

However, the amazing new property discovered by researchers can have lasting impacts on gene therapy research. Gene therapy is the manipulation of genes within the body's tissue cells with the goal of treating disease. It can correct defective genes which are responsible for disease development.

The problem is how to manipulate the genes. For a long time, scientists have known that viruses reproduce by binding to their hosts and introducing their unique genetic material into the cell. This genetic material gives instructions to the cell to produce copies of itself, hijacking the cell’s natural production. For gene therapists, viruses can be used to manipulate cells with "good" genetic material. This is known as the viral vector.

The new study recently published in the journal Human Gene Therapy claims that caffeinated cells used to produce viruses for gene therapy can generate up to 8 times more than non-caffeinated cells. According to the researchers, using caffeine should decrease the cost of producing lentiviruses for research and clinical uses. Lentiviruses are a common type of virus used in gene therapy.

"It is ironic that the ingredient in beverages like colas and coffees that helps keep us awake and alert is also useful in jazzing up cells to produce more gene therapy vectors. An increase in vector production of 5-fold may prove critical in establishing the commercial viability of lentiviral based products," says James M. Wilson, MD, PhD, and Director of the Gene Therapy Program.

The researchers emphasize that the timing of introducing caffeine into cells is critical for increased virus production. Also the concentration of caffeine cannot be too high because it can be toxic to the cells, and would not cause them to increase virus production.

Researchers involved with the study from the University of Texas Southwestern Medical Center, Dallas include Brian Ellis, Patrick Ryan Potts, and Matthew Porteus. Their work can be found in the journal Human Gene Therapy which is published by Mary Ann Liebert, Inc.

Link to published article: http://www.liebertpub.com/contentframe.aspx?code=MDoqsls2tWBQ0c%2bZWT0nPtZ1zyJ60HXWr8kmqZBHbUfkxIBDwf3RDtPbRDToWe2xigdyewz

source:http://www.enn.com/top_stories/article/42297