NANOTECHNOLOGY

Thursday, 19 December 2013

DNA Clamp to Grab Cancer Before It Develops

Dec. 19, 2013 — As part of an international research project, a team of researchers has developed a DNA clamp that can detect mutations at the DNA level with greater efficiency than methods currently in use. Their work could facilitate rapid screening of those diseases that have a genetic basis, such as cancer, and provide new tools for more advanced nanotechnology. The results of this research is published this month in the journal ACS Nano.

Artist’s rendering of the discovery: the research team took advantage of the ability of certain DNA sequences to form a triple helix, in order to develop a DNA clamp. This nanometer-scale clamp recognizes and binds DNA sequences more strongly and more specifically, allowing the development of more effective diagnostic. Professor Alexis Vallée-Bélisle, Department of Chemistry, Université de Montréal worked with the researcher Andrea Idili and Professor Francesco Ricci of the University of Rome Tor Vergata, and Professor Kevin W. Plaxco, University of California Santa Barbara, to develop this diagnostic nanomachine. (Credit: Marco Tripodi)

Toward a new generation of screening tests
An increasing number of genetic mutations have been identified as risk factors for the development of cancer and many other diseases. Several research groups have attempted to develop rapid and inexpensive screening methods for detecting these mutations. "The results of our study have considerable implications in the area of diagnostics and therapeutics," says Professor Francesco Ricci, "because the DNA clamp can be adapted to provide a fluorescent signal in the presence of DNA sequences having mutations with high risk for certain types cancer. The advantage of our fluorescence clamp, compared to other detection methods, is that it allows distinguishing between mutant and non-mutant DNA with much greater efficiency. This information is critical because it tells patients which cancer(s) they are at risk for or have."
"Nature is a constant source of inspiration in the development of technologies," says Professor Alexis Vallée-Bélisle. "For example, in addition to revolutionizing our understanding of how life works, the discovery of the DNA double helix by Watson, Crick and Franklin in 1953 also inspired the development of many diagnostic tests that use the strong affinity between two complementary DNA strands to detect mutations."
"However, it is also known that DNA can adopt many other architectures, including triple helices, which are obtained in DNA sequences rich in purine (A, G) and pyrimidine (T, C) bases," says the researcher Andrea Idili, first author of the study. "Inspired by these natural triple helices, we developed a DNA-based clamp to form a triple helix whose specificity is ten times greater than a double helix allows."
"Beyond the obvious applications in the diagnosis of genetic diseases, I believe this work will pave the way for new applications related in the area of DNA-based nanostructures and nanomachines," notes Professor Kevin Plaxco, University of California, Santa Barbara. "Such nanomachines could ultimately have a major impact on many aspects of healthcare in the future."
"The next step is to test the clamp on human samples, and if it is successful, it will begin the process of commercialization," concludes Professor Vallée-Bélisle.

New Pictures of the Solar Corona from IRIS

NASA Captures Unprecedented Views of Sun's Mystery Layer

During its first six months in space, NASA's IRIS telescope has snapped stunning images of an obscure layer of the sun, revealing previously unseen violence and complexity in the lowest slivers of our star's atmosphere, scientists say.
Solar

The IRIS Observatory launched in June and its name is short for Interface Region Imaging Spectrograph. The small spacecraft is designed to collect data on the interface region, a little-understood area spanning the 3,000 to 6,000 miles between the solar surface and outer atmosphere, or corona.
Scientists have hoped IRIS could shed light on some of the sun's secrets, such as why temperatures shoot from 10,000 degrees Fahrenheit at the sun's surface to about 1.8 million degrees F at the corona. Researchers working on the mission presented some of the probe's observations thus far Monday at the American Geophysical Union meeting in San Francisco.
IRIS snaps high-resolution images every few seconds and can capture areas of the sun as small as 150 miles. The spacecraft is also equipped with a spectrograph that analyzes the sun's light, splitting it into various wavelengths, which can reveal variations in temperature, density and velocity. Supercomputers on the ground help check this data against current models of the sun.
"We are seeing rich and unprecedented images of violent events in which gases are accelerated to very high velocities while being rapidly heated to hundreds of thousands of degrees," Bart De Pontieu, the IRIS science lead at Lockheed Martin, said in a statement. "These types of observations present significant challenges to current theoretical models."
In particular, DePontieu has been focusing on IRIS's data on two solar features: prominences and spicules.
video:
http://www.space.com/22138-iris-vs-sdo-new-sun-observatory-raises-the-resolution-video.html

Extending above the sun's surface, prominences are cool, giant loops of solar material that can lead to solar storms when they erupt. DATA from IRIS revealed that highly dynamic and finely structured flows sweep through these prominences, mission scientists said.
Spicules, meanwhile, are huge fountains of gas that shoot away from the sun's surface at 150,000 miles per hour and may play a role in heating the corona. IRIS data has allowed researchers to see for the first time how spicules evolve, according to NASA.
"We see discrepancies between these observations and the models and that is great news for advancing knowledge," Mats Carlsson, an astrophysicist at the University of Oslo in Norway, said of IRIS's data on prominences and spicules. "By seeing something we don't understand we have a chance of learning something new."
IRIS is part of NASA's Small Explorer program, an effort to fund missions that cost less than $120 million. Designed by Lockheed Martin, the spacecraft is just 400 pounds and measures just 7 by 12 feet with its power-generating solar panels deployed.