2009 AIP Industrial Physics Forum: Thermal therapy is being used to kill cancer cells in tumors that other methods fail to eliminate, but there is the risk of overheating healthy cells, or not heating the tumor cells enough.
A new idea for improving thermal therapy was recently published in Proceeding of the National Academy of Sciences and presented at the AAPM session “Frontiers in Medical Physics,” by Leo Xuanfeng Ding from Wake Forest University. Using multi-walled carbon nanotubes (MWCN’s) Ding and his collaborators hope to make guided laser cancer removal safer and more effective.
The treatment injects cancer tumors with MWCN’s, and uses a guided near infrared laser to heat them up and deliver a fatal temperature rise to the cancer cells. The laser pulse is low energy (3 W/cm2) and fast (30 seconds per dose). The team uses Magnetic Resonance Temperature Imaging, MRTI, to identify the tumor and then to monitor the tumor’s temperature as well as the temperature of the surrounding tissue. Trials with mice showed a significant rise in the temperature of the cancer cells injected with the MWCN’s, compared to without. And, the tumors were far less likely to come back.
Monthly Archives: July 2009
Tourists flock to US nuclear facility
BBC NEWS: America’s first nuclear weapons production facility has become the center of a growing tourism industry.
More than 60 years after plutonium was first produced at Hanford, Washington State, the US government is running limited visits to the site.
Many locals are proud of their heritage, but Hanford has left another legacy: massive radioactive contamination.
And now billions of dollars of President Obama’s stimulus money is being spent on cleaning up what is one of the most polluted places in the US.
Physics police work on hit-and-runs
Star-Banner: If you decided to take a nighttime walk down one of the county’s unlit roads while wearing dark clothing, adding a ball cap to your attire might make work easier for Florida Highway Patrol troopers serving as traffic homicide investigators.
“Normally a ball cap will land close to the point of impact,” when a pedestrian is struck by a motor vehicle, said FHP Corporal Mark Weber.
Weber is one of six FHP traffic homicide investigators—part physicist, part policeman, and part victim’s advocate—who probe fatal crashes in unincorporated parts of the county.
Seeing Altinum after more than 1500 years
Various: How do you map a city with no visible ruins?
In July 2007, during a severe drought, Paolo Mozzi, a geomorphologist at the University of Padua in Italy, and his team took aerial photos of Altinum, a Roman trading center that thrived between the 1st and 5th centuries CE, that lay beneath farm fields close to Venice, reports the BBC and ScienceNow. The photos were taken in several wavelengths of visible light and in near-infrared, with a resolution of half a meter.
Above left is a digitally enhanced false-color composite image (NIR, red and green spectral bands) of the center of Altinum, with maize and soy crop marks. The right image is the interpretation of left image. Credit: Andrea Ninfo et al., Science (31 July 2009)
When the images were processed to tease out subtle variations in plant water stress, a buried metropolis emerged. Lighter crops traced the outlines of buildings—including a basilica, an amphitheater, a forum, and what may have been temples—buried at least 40 centimeters below the surface. To the south of the city center runs a wide strip of riper crops. They were growing above what clearly used to be a canal, an indication that Venice’s Roman forebears were already incorporating waterways into their urban fabric.
Related Links
The Map of Altinum, Ancestor of Venice Science
Maps reveal Venice ‘forerunner’ BBC
Ancient Roman City Rises Again ScienceNow
The future of China’s space program
NPR: In the last century, space exploration was dominated by the superpowers and developed nations. This century, developing nations, particularly in Asia, have begun rolling out ambitious space programs.
Chief among them is China, which in 2003 became the third country after the US and the Soviet Union to put a human in space. China may be a latecomer to the field, but it has big plans.
Accepting math papers that other journals reject
The Economist: Paul Lauterbur, the father of magnetic-resonance imaging, had his seminal paper rejected when he first submitted it to Nature. Peter Higgs, eponymous predictor of physics’s missing boson, faced similar trouble with Physics Letters. But Lauterbur went on to win a Nobel prize for his work, and Higgs is an odds-on favourite to get one soon. A good, rejected paper, then, is by no means an oxymoron.
And that observation is the basis of Rejecta Mathematica, an open-source academic journal that recently went online. As its name suggests, the new journal publishes only papers that, like Lauterbur’s and Higgs’s, have been previously submitted to, and rejected by, others.
Canada and Japan were blocking climate-change deal says former UK science adviser
Times Online: London Canada and Japan were blocking a possible deal on climate change at the Copenhagen summit, Sir David King, the former Chief Scientific Adviser, warned yesterday.
Speaking at the World Conference of Science Journalists, Sir David said that the two countries had stepped into the breach left by the Bush Administration, which had strongly resisted cutting CO2 emissions.
“Copenhagen [the site of upcoming global emission talks this december] is faltering at the moment,” said Sir David. “The Americans are now fully engaged. But several countries are blocking the process.”
Governments previously were able to hide behind the US’s intransigence on climate change, he said, but the pro-climate policies being launched by the Obama administration means this is no longer possible. “The time has come for people to reveal their cards,” he told delegates.
Opinion: Why we need space travel
Nature: Giovanni Bignami reflects on the people who persuaded him that we must send humans beyond Earth’s orbit to inspire public and political support for science.
A gamma camera to search for cancer
2009 AIP Industrial Physics Forum: For the past six years, Michael O’Connor and his colleagues at the Mayo Clinic have been investigating different molecular imaging techniques for screening for breast cancer, in the hope of finding a cheaper, equally reliable method to MRI.
They’ve focused many of their efforts on scintigraphy, which images the body by catching gamma rays emitted from the patient (thanks to an injected radioactive tracer), rather than passing xrays through them.
The gamma camera itself contains crystals that respond to the gamma rays by emitting a little pop of light. Collectively they create an image.
These crystals can be operated at room temperature, and they have no “dead space” so you can get very close to the breast tissue.
In a clinical trial of dense breast tissue the gamma camera caught 10 tumors out of 12 while the mammogram only caught 3. Its resolution is comparable, but not better than MRI.
However, the camera does have some drawbacks , reports AIP’s Calla Cofield. The radiation dose used is 6–7 times larger than a standard mammogram.
Related Link
2009 AIP Industrial Physics Forum
Comet may have hit Siberia in 1908
Science News: Michael C. Kelley, an atmospheric physicist at Cornell University, and his colleagues suggest in the July 28 Geophysical Research Letters that data gleaned from analyses of high-flying clouds formed by the space shuttle after takeoff, as well as knowledge about the speed at which shuttle exhaust wafted to polar regions, now hint that the Tunguska blast of June 1908 resulted from a comet slamming into Earth’s atmosphere.
Related Links
The Tunguska event
Two-dimensional turbulence, space shuttle plume transport in the thermosphere, and a possible relation to the Great Siberian Impact Event