martes, 26 de agosto de 2008


AUSTIN, Texas, Aug. 19, 2008 -- A new grant will allow a researcher to continue developing and testing a device that uses light to detect skin cancer without the need for an invasive biopsy. University of Texas at Austin biomedical engineer James Tunnell has been awarded a $260,000 Phase II Early Career Award from the Wallace H. Coulter Foundation. The grant will support his work for the next two years to refine the device called a "clinical spectrometer" and to conduct additional clinical trials. He previously received one of 23 Phase I awards from the foundation, and was one of seven Phase II awards selected from that pool to continue his research. Using a pen-sized probe, weak pulses of light are emitted from the tip onto the skin or tissue and then recaptured by the probe and sent back to a computer system for analysis.

"Within a second, it can take a measurement and tell you whether or not its cancer," said Tunnell, an assistant professor at the university. "And you can move the probe around quickly to different spots of the skin." The light measures the cellular and molecular signatures of skin cancer without the need for a biopsy or the excision of a tissue sample. "It can tell if the structures of the cells and the biochemicals present are associated with the progression of these cancers," Tunnell said. "Many biopsies and surgeries would be unnecessary if you had a device that could catch the cancer earlier and identify the margins of where it exists."

Throughout the world, melanoma, the most serious form of skin cancer, has been increasing over the past 20 years, accounting for 3 percent of cancer deaths. In the United States, more than one million new cases occur annually, according to the National Cancer Institute (NCI). Survival rates increase substantially when the disease is diagnosed at an early stage. So far, the device has been tested on 80 people in clinical trials at M.D. Anderson Cancer Center in Houston and with The University of Texas Medical Branch clinicians in Austin. A total of 300 people will be screened at those institutions using the device. "The early results look very promising," Tunnell said.


Northwestern University nanoscientist Chad A. Mirkin, who led the study, and his colleagues printed the logos as well as an integrated gold circuit using a new printing technique, called Polymer Pen Lithography (PPL), that can write on three different length scales using only one device. The new printing method could find use in computational tools (the electronics that make up these tools), medical diagnostics (gene chips and arrays of biomolecules) and the pharmaceutical industry (arrays for screening drug candidates), among others.

"While watching the Olympics opening night ceremonies I was delighted to see that printing was highlighted as one of ancient China's four great inventions," said Mirkin, George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences, professor of medicine and professor of materials science and engineering. "We consider Dip-Pen Nanolithography (DPL), which is nanotechnology's version of the quill pen, and now Polymer Pen Lithography to be two of Northwestern's most important inventions." Polymer Pen Lithography uses arrays of tiny pens made of polymers to print over large areas with nanoscopic through macroscopic resolution. By simply changing contact pressure (and the amount the pens deform), as well as the time of delivery, dots of various diameters can be produced. (The pen tips snap back to their original shape when the pressure is removed.)

"We can go, in a sense, from an ultrafine-point Sharpie® to one with a fat tip," said Mirkin, director of Northwestern's International Institute for Nanotechnology. "The tip of each polymer pen starts with nanometer-scale sharpness, but if we press down harder the tip flattens out. This gives us great flexibility in the structures we can produce." In the case of the Olympic logo, the researchers started with its bitmap image and uniformly printed 15,000 replicas onto a gold substrate using an "ink" of the molecule 16-mercaptohexadecanoic acid. (The ink is one molecule thick.) This took less than 40 minutes.

The letters and numbers, "Beijing 2008," were generated from approximately 20,000 dots that were 90 nanometers in diameter. Then, with more force applied to the pens, the stylized human figure and the Olympic rings were made from approximately 4000 dots that were 600 nanometers in diameter.

sábado, 2 de agosto de 2008

Alternative energy sources

One of the biggest interests in research right now is to find alternative energy sources to help overcome the current energy crisis we are facing. One important research topic is to find a way to purify water at a lower price and using less energy; this will help people in both industrialized and developing countries considerably. Eric Hoek and his research team at the University of California at Los Angeles created a membrane of nanoparticles that aims to reduce the cost needed to desalinate seawater and clean wastewater. This groundbreaking technology may be adapted in municipal desalination plants in water-thirsty areas. In an effort to bring about new energy sources, a newsletter, NanoFrontiers, discusses the international nanotechnology research and development news. It explores the question of whether developing nations will share the benefits of nanotechnology with other countries. The examples include nanotechnology advances in therapeutic and preventive treatments for HIV/AIDS, "fog harvesting" in Thailand, China and Nepal and improved desalination technology to turn seawater into drinking water.
The publication of these investigations was led by Visions for the Future of Nanotechnology and written by Karen F. Schmidt
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