Recently in Medical physics Category

Daily Mail: Neuroscientists at the University of California, Berkeley, have been developing a computer program that can decode brain activity and put it into words, writes Tamara Cohen for the Daily Mail. To monitor information from the temporal lobe, where sounds are processed, the scientists inserted electrodes into the brains of 15 patients whose skulls had been cut open for an epilepsy treatment. As the patients listened to a person speaking, the computer analyzed how the brain processed the words they heard. It was able to translate the spoken words into patterns of electrical activity and then translate them back into the original sounds, or something very similar. Brian Pasley, coauthor of a paper published in PLoS Biology, said that with more work, brain recordings could allow scientists to "synthesize the actual sound a person is thinking." Such technology could benefit people whose speech has been affected by stroke or degenerative disease.

BBC: Researchers at the Stanford University School of Medicine have succeeded in converting mouse skin cells into "neural precursor" cells, which can develop into three types of brain cell. The group's findings, published in the Proceedings of the National Academy of Sciences, may be important for certain medical therapies, such as bone marrow transplants. Until now such transplants have relied on stem cells, which can divide and differentiate into many different specialized cell types. Stem-cell research has been hampered by ethical concerns, however, because one source of the cells has been human embryos. More work will have to be done to re-create the experiment using human skin cells.

BBC: Researchers at Duke University have been working to develop synthetic nanoparticles that can boost the human body's immune system. They have engineered tiny capsules that mimic mast cells—which respond to fight infections near the skin—by releasing a body chemical called tumor necrosis factor, which battles certain types of bacteria and viruses. The nanoparticles, when injected into mice simultaneously with a vaccine, have been shown to improve the infected animals’ survival rate. Soman Abraham and colleagues said different immune system chemicals could be added to the nanoparticles, depending on which vaccine will be used.

BBC: Global climate shifts and flu pandemics may be linked, say researchers. Weather can influence the migratory patterns of wild birds; thus different species are brought together that don’t normally mix. The birds then share viruses, which can morph into different strains to which the human population has not been previously exposed. In a paper published yesterday in the Proceedings of the National Academy of Sciences, Jeffrey Shaman of Columbia University and Marc Lipsitch of Harvard University note that the four most recent human influenza pandemics—in 1918, 1957, 1968, and 2009—were preceded by a climate pattern called La Niña. However, the researchers emphasize, most La Niñas have not preceded a pandemic. Rather, climate patterns could be one of several factors that affect the spread of viruses.

Inside Science: The American Association of Physicists in Medicine (AAPM) has stated that the benefits of diagnostic radiation procedures far outweigh the risks. Specifically, the association said that the risks from medical imaging at effective doses below 50 millisieverts for a single procedure, or 100 mSv for multiple procedures over a short period of time, are so low as to be undetectable. A full-body CT scan results in 12 mSv; a mammogram, 0.13 mSv. The risks from those procedures, according to AAPM, are too low to have been determined reliably and may be "nonexistent." Media stories uncovering improper use of machines that use much higher levels of radiation to treat cancer and journal articles cautioning physicians to minimize diagnostic CT scans in children have raised unfounded fears about radiation procedures in general, AAPM said. The scientific community is not unanimous on the issue, and the statement has drawn criticism from scientists who think that even very small doses of radiation are potentially damaging.

BBC: A radiologist at the University of Minnesota is using computed tomography (CT) to replicate antique musical instruments. Steven Sirr first got the idea to take a CT scan of a violin in 1988. Such scans, he discovered, can reveal characteristics of the wood, worm holes and cracks, and previous repairs, all of which help create an instrument’s unique sound. Teaming up with a couple of violin makers, Sirr used more than 1000 CT images to reproduce a 1704 Stradivarius violin borrowed from the US Library of Congress. Over the years, the team has scanned hundreds of instruments, including guitars, mandolins, and other violins. "The copies are amazingly similar to originals in their sound quality," said Sirr, who hopes that the process will allow more music students to have access to high-quality instruments on a par with rare vintage pieces. The team’s findings were presented at a Radiological Society of North America conference.

BBC: Current cancer treatments involve radiation, surgery, or drugs that kill the cancerous cells. All three have side effects that can damage healthy tissue. Makoto Mitsunaga and colleagues at Maryland's National Cancer Institute have demonstrated a more precisely targeted therapy. They created a photosensitizer specific to cancer cells by combining an antibody that targets proteins on the surface of cancerous cells with a chemical, IR700, that is activated when hit by near-IR light. They then implanted squamous cell carcinoma tumors into the backs of mice, gave the mice the antibody-IR700 combo, and exposed them to near-IR light. Near-IR can penetrate several centimeters into the skin; it activated the drug, and tumor volume in the mice was significantly reduced, with no observable toxic effects.

Science: The International Classification of Diseases has served for more than 100 years as a standard for the World Health Organization, physicians, and the healthcare industry to track disease incidence, make diagnoses, and determine reimbursement for care. Last year, however, the National Institutes of Health decided it was time to update it. What the resulting National Research Council panel has proposed is a massive data network that would combine cutting-edge genomic and molecular data on patients' diseases with their routine medical records, writes Jocelyn Kaiser for Science. That system would be used to develop a new disease taxonomy and personalize medical care, according to the 108-page report, titled Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease. Creating such a network of data is expected to take a decade or two, and it will require a change in the public’s attitude toward patient privacy and the use of personal medical data for research.

BBC: A team of researchers at the Joseph Fourier University in Grenoble, France, is working on a biofuel cell that uses glucose and oxygen at concentrations found in the human body to generate electricity. Serge Cosnier and colleagues estimate that within a decade or two, biofuel cells may be used to power a range of medical implants, from sensors and drug delivery devices to entire artificial organs, writes David Cohen for the BBC. The fundamental limitation on such devices has always been the battery needed to keep them running; whereas batteries need to be continuously replaced over a patient’s lifetime, biofuel cells could keep working indefinitely. A biofuel cell is made of two special electrodes. One removes electrons from glucose, and the other donates electrons to oxygen and hydrogen molecules, producing water. Although biofuel cells were first proposed in the 1970s, recent breakthroughs in the understanding of enzymes have resulted in several groups around the world working on such devices.

Medical News Today: An “intelligent” T-shirt has been developed that can monitor body temperature and heart rate, locate the wearer within a hospital, and even determine whether the person is sitting, walking, running, or lying down. Researchers at Carlos III University in Madrid say their device could allow doctors to monitor patients at home and thus reduce the length of hospital stays. The garment is made of textiles that have electrodes integrated into the fabric. Data is collected by an acquisition device worn around the neck under the shirt, which sends the data wirelessly to a management system. The device also includes a thermometer and accelerometer. “The idea of it is to be nonintrusive,” said developer Jose Ignacio Moreno to the Daily Mail. “The patient can be monitored in real-time without any cables due to the wireless platform, so they can stay in bed or walk around as they wish.”

Washington Post: The way our brains interpret visual stimuli has been translated into video. Jack Gallant of the University of California, Berkeley and colleagues used functional magnetic resonance imaging (fMRI) to measure the blood flow through the brain's visual cortex as test subjects watched video clips. The participants' brain activity was recorded by a computer program, which learned how to associate the visual patterns in the video clips with the corresponding brain activity. Test participants then viewed a second set of clips, and the resulting brain activity was used to test the computer's reconstruction algorithm, which was fed 18 million seconds of random video from YouTube that the participants had not seen. The program then chose the hundred clips that were most similar to the video the subjects had watched and combined them to produce a rough reconstruction of the original video. The process, while indirect, is still a dramatic and somewhat eerie demonstration of how the human brain sees things.

Nature: Fluorescent labels have helped surgeons spot cancerous ovarian cells smaller than a millimeter in size. About 90% of malignant ovarian tumors have high numbers of receptors for the molecule folate. Vasilis Ntziachristos of the Technical University of Munich in Germany and colleagues attached folate to the fluorescent molecule fluorescein iso-thiocyanate, then injected it into patients. Cells with excess folate receptors, now effectively labeled with the glowing molecule, shone white when viewed with a specially designed camera and light. Surgeons were then able to find and remove cancerous tissue that would otherwise have been indistinguishable from healthy ovarian tissue.

Washington Post: A recent federal study found that screening heavy smokers and former smokers who are 55–74 years old reduced by 20% the chances of their dying of lung cancer. As a result, CT scans are being used more frequently to screen people for lung cancer, prompting significant disagreement about how widely the testing should be done. Lung cancer, the leading cause of cancer death in the US, is still difficult to treat, partly because it's often diagnosed late. The three-dimensional images created by CT scans are more detailed than 2D x rays and, therefore, more likely to reveal small tumors in the lungs, earlier in the course of the disease. The potential downside is that greater detail can produce more false positives, and follow-up procedures, such as biopsy and surgery, have significant risks of their own; of the 16 patients in the study who died of follow-up procedures, 6 did not have cancer. Some testing centers are offering CT scans to patients outside the age and risk profile of the test participants, which may increase the false-positive rate as well as the number of unnecessary and risky follow-up procedures performed.

Nature: Genetic diseases such as hemophilia may one day be treated through a gene-editing process. Katherine High, a hemophilia researcher at the Children's Hospital of Philadelphia, teamed up with researchers at Sangamo BioSciences in Richmond, California, who are experts on enzymes called zinc-finger nucleases (ZFNs). They treated hemophilia in mice that were engineered to carry the faulty human gene; the researchers used ZFNs as molecular scissors to cleave the genome at the F9 gene—where people with hemophilia B have multiple mutations—and insert a healthy gene. After treatment, the animals' blood clotted in 44 seconds, compared with more than a minute for mice with hemophilia. "In theory, almost all genetic diseases could be amenable to this type of treatment," said Mark Kay, a gene-therapy researcher at Stanford University. Much more work must be done, however; many questions remain about how to get the right amount of DNA to the right cells and how to guarantee the ZFNs cut the right bit of DNA. High and colleagues' work was published yesterday in Nature.

Nature: Sangeeta Bhatia of MIT and colleagues have designed two different types of cancer-fighting nanoparticles to work in tandem and piggyback on the body's rapid response to clotting, writes Nature's Corie Lok. Bhatia's team created a scout particle to fit through the abnormally large pores in a tumor's blood vessels; when near-IR light is shone on the scout particles, they heat up just enough to damage the tumor and trigger a rapidly escalating molecular response known as the clotting cascade. The drug-bearing nanoparticle has a protein on its surface that is a substrate for an enzyme called factor XIII, which crosslinks fibrin at the end of the cascade; the particles are attracted as the clotting process occurs. Factor XIII crosslinks the nanoparticles' protein to the fibrin in the clot, and the particles then deliver the drug. The factor XIII and fibrin generated during the clotting process create additional binding sites for the particles; that process leads to a 40-fold increase in the amount of drug delivered compared with drug-delivering nanoparticles already in use.

BBC: A new imaging method can detect the electrical activity in the brain in the moments after anesthesia is administered, writes Jennifer Carpenter for the BBC. The new technique, called functional electrical impedance tomography, is more compact than other imaging techniques and is easily transported to the operating room. Tens of electrodes attached to the patient's head send low electrical currents through his or her skull; the currents are impeded by the brain's tissues and electrical signals. As anesthesia begins to take effect, different parts of the brain seem to be communicating, possibly inhibiting one another to produce unconsciousness. The technique could be used to monitor brain activity after a stroke or head injury and could give insight into the nature of consciousness in general.

Science: A laser built into a single cell may one day be used for light-based therapeutics, writes Jon Cartwright for Science. Physicists Malte Gather and Seok-Hyun Yun of Harvard Medical School used cells derived from a human kidney and added the DNA that codes for green fluorescent protein (GFP), then placed some of the cells producing GFP between two mirrors a single cell's width apart. To lase, the GFP in the cells needed to be pumped with another laser, which sends pulses of blue light at about 1 nanojoule. The light bounced back and forth, amplifying the diffuse light from the GFP into a coherent green beam. Gather and Yun are interested in the therapeutic applications of their device. They also speculate that it might eventually help the backbone of optical communications shift to biotechnology.

CNET: Currently the only method for thinning blood, and thus reducing the risk of heart attacks and strokes, is through drugs such as aspirin. But physicists at Temple University in Philadelphia have been working on a procedure that uses magnets. Rongjia Tao and coworkers were able to use a magnetic field of 1.3 tesla (roughly equivalent to what is used in magnetic resonance imaging) to polarize red blood cells, which contain iron, thereby causing those cells to link together in short, streamlined chains, writes Elizabeth Armstrong Moore for CNET. The blood then flowed more smoothly through the blood vessels, and the friction along the walls was reduced. The researchers found that after just 1–12 minutes of exposure to the magnetic field via a 1000-pound magnet, blood viscosity decreased by 20–30% for several hours. Eventually, blood viscosity returned to previous levels. Unlike the ionizing radiation found in CT scans, Tao’s method is not expected to have any harmful biological effects. The study is to be published in the journal Physical Review E.

Science: The safety of the full-body x-ray scanners used at airports is being questioned by several scientists. Five professors at the University of California, San Francisco, and one at Arizona State University have written a letter to White House science adviser John Holdren in which they question why the Transportation Security Administration won’t allow independent testing of the scanners by outside scientists. Although the TSA says the scanners have already been evaluated by the Food and Drug Administration, NIST, and the Johns Hopkins University's Applied Physics Laboratory, the letter writers point out flaws in the testing. In addition, studies published in scientific journals in the last few months have also “cast doubt on the radiation dose and the machines' ability to find explosives,” according to Michael Grabell of ProPublica.

Daily Mail: A super-resolution microscopy technique developed at Sandia National Laboratories is allowing researchers to study a cell membrane with extraordinary spatial resolution. The technique builds on super-resolution capabilities developed in recent years, but it goes another step by adding dual-color capabilities to the relatively new stochastic optical reconstruction microscopy, or STORM. Sandia researchers Jesse Aaron, Jeri Timlin, and Bryan Carson have been using the new technique to discover why a cell can defend against some invaders, such as Escherichia coli, while failing against others, such as the bacteria that cause bubonic plague. They have been able to view the clustering of receptor proteins—tasked with recognizing intruders—on the surface of immune cells when those proteins are confronted with lipopolysaccharides derived from E. coli; LPS derived from bacteria that cause the plague do not cause the same effects. Such studies could open doors to new diagnostic, prevention, and treatment methods. For more details, see Sandia’s press release.

Science: Traditional microscopes can't resolve objects smaller than half the wavelength of the light used to illuminate them; electron microscopes get around this by replacing the visible light with electron beams, which have a much shorter wavelength and a much smaller intrinsic blur. However, electrons pass right through thin samples of most living tissue unless it's been prepared in a radical way—which prevents researchers from viewing living organisms. E. G. van Putten, of MESA+ Institute for Nanotechnology in Twente, the Netherlands, and colleagues etched a gallium phosphide lens with sulfuric acid to produce a frosted surface that scattered light in all directions. They then used a computer to design a light wave that, when passed through and scattered by the lens, would focus to a point. It seems counterintuitive, but the randomization and reconstruction process allowed the researchers to form a sharper image than would otherwise have been possible. They were also able to create an ultrasharp image of the entire sample by rotating the incoming light wave and scanning the focus across the sample. Thus far, they have imaged gold nanoparticles with a resolution as small as 97 nm. With a more powerful light source and some fine-tuning, it should be possible to see details of living tissue samples, including nanoscale processes such as viruses invading cells.

Los Angeles Times: A US appeals court ruled last week that federal funding for stem cell research may continue, writes David G. Savage for the Los Angeles Times. Last year US District Judge Royce Lamberth ordered a temporary halt to new research grants because he believed the funding appeared to violate a 15-year-old congressional ban on using federal money for research in "which embryos are destroyed." Since 1999 the National Institutes of Health had interpreted the ban more narrowly. Its lawyers said that stem cells are not "embryos" and, that while no federal funds may be used to destroy embryos in order to extract stem cells, the funds may be used for research on stem cells that already exist. Although some states have used their own money to fund embryonic stem cell research, "federal funding is still the engine that drives this train," said Sidney Golub, an expert on stem cell research policy at the University of California, Irvine. "That's why this decision is very important."

New Scientist: Two techniques involving magnets could significantly reduce the time it takes—from days to hours—to diagnose a fatal infection, writes Jessica Hamzelou for New Scientist. A team at MIT has created a device that uses magnetic resonance to detect a fungus called Candida, which has a 40% mortality rate. Because there are five species of Candida, the team engineered five types of molecular probe, each of which contains a magnetic particle. When the probes are put into blood samples and a magnetic pulse is applied, the water molecules begin to spin; the time it takes for the molecules to return to rest determines whether a species of Candida is present and how much of it there is. A second team at Harvard University has been working to diagnose sepsis. Team members coated magnetic particles with an immune-system protein that binds to the cell walls of pathogens in the blood. The entire cluster can be pulled out using a magnet, and the pathogen can then be identified. "In my opinion both techniques could significantly advance the field of diagnostics.... It's pretty cool," said Dirk Kuhlmeier at the Fraunhofer Institute for Cell Therapy and Immunology in Leipzig, Germany.

New Scientist: A company based in Australia has been working on a cochlear implant for the hearing impaired. Unlike a traditional hearing aid, which acoustically amplifies sound, the bionic device translates sound into electrical signals that are used to electrically stimulate the cochlea—a spiral-shaped part of the inner ear attached to the auditory nerve, writes Duncan Graham-Rowe for New Scientist. Because of its small size, the new device can be fully implanted in a patient's ear—unlike current devices, which require an external unit containing the power supply, processors, and microphone. The fully implantable system, would, however, require replacement every 10 years when its batteries run out.

The Independent: A medical trainer and a Hollywood special-effects artist have teamed up to produce more realistic training dummies for university hospitals. Jane Kleinman, who trains future doctors and nurses at Loma Linda Hospital in East Los Angeles, got the idea to form the company Simureal when she saw the realistic scene in the movie 127 Hours in which James Franco’s character amputates his own arm with a blunt penknife. Kleinman tracked down the arm’s creator, Tony Gardner, and together they are using his state-of-the-art expertise to create silicone training aids. "It's incredible for a guy like me, who’s worked in film for years, to realize that the stuff we do can also affect people in the real world, in a life-or-death situation," said Gardner at his workshop in the LA suburb of Irwindale last week.

BBC: Weeks after Wilhelm Röntgen published his discovery of x rays in 1895, the directors of a high school and a hospital in Maastricht, the Netherlands, built their own x-ray imager. Now, more than a century later, Gerrit Kemerink of Maastricht University Medical Center has tested the old device, comparing it with a modern x-ray imager. In a paper to be published in Radiology, Kemerink reports that the old device produces images that are blurrier than those produced by its modern counterpart. Nevertheless, the vintage images are of medically useful quality. They do, however, require the use of radiation doses that are unacceptably high by modern standards.

BBC: A team from the US and Canada has built a miniaturized scanner that can perform positron emission tomography (PET) on mobile, wide-awake rats. The new scanner, which is described in a paper in Nature Methods, is potentially useful because PET is a molecular probe. Thanks to the use of radioactive tracers, PET can locate concentrations in the brain of neurotransmitters and other biochemically significant molecules. Subjecting lab rats to PET scans usually entails immobilizing and anesthetizing them, a restriction that limits the kinds of brain activity that can be studied. The new scanner is small enough and light enough that it can be attached to a rat's head while the rat moves about.

NPR: Nanodiamonds—clusters of a few hundred carbon atoms—may find a use in the treatment of cancer. Researchers at Northwestern University infected lab mice with chemo-resistant breast and liver cancers and then tested two treatments. Mice that were injected with nanodiamonds covered in the drug doxorubicin fared better than those given unbound doxorubicin. Nanodiamond-bound doxorubicin tends to stick around in mice up to 10 times longer than unbound doxorubicin does, leading to a slower, more sustained therapy. The high retention of the nanodiamonds within tumors means that smaller, less harmful doses can be used. As nanodiamonds are already in use in the automotive industry as a lubricant, they are mass-produced and don’t cost much. The results of their work appear in the latest issue of Science Translational Medicine.

BBC: Researchers in the UK and Singapore have demonstrated the highest-resolution optical microscope ever—imaging objects down to just 50 nanometers. Ordinarily, it's impossible to use visible light to resolve objects smaller than its wavelength (380–750 nm). However, you can beat this diffraction limit by detecting "evanescent" waves, whose intensity falls to zero within one wavelength of the emitter's surface. As reported in Nature Communications, the new technique uses tiny glass beads to gather evanescent light waves and refocus them, channeling them into a standard microscope. It is believed that the technique holds great promise for biological studies, for viewing cells, bacteria, and viruses.

New Scientist: James Urquhart, writing for New Scientist, describes a camera inspired by the operation of the human eye. The camera can zoom without the need for bulky lenses, making it more compact than conventional cameras. The device builds on a non-zooming eyeball camera developed in 2008 by John Rogers of the University of Illinois at Urbana-Champaign. Now he has given the technology a twist by building in a stretchable lens and a flexible photodetector whose shape alters as the magnification of the lens changes. The technology could be used in such devices as night-vision cameras and endoscopes.

New Scientist: Argento Diagnostics, a company spun off from the UK's National Physical Laboratory, has used nanotechnology and microfluidics to tackle a problem in the training of elite athletes: How do you monitor the levels of key metabolic molecules without having to send samples to a lab? Argento's solution is a handheld device that can take a sample of an athlete's blood, saliva, or urine and send it through microfluidic channels, where it mixes with silver nanoparticles and larger magnetic nanoparticles, both of which are coated with antibodies. In the presence of a biomolecule of interest, the silver nanoparticles stick to the magnetic nanoparticles. Flushing off the silver nanoparticles creates a concentration of silver ions whose charge is proportional to the amount of biomolecule in the sample.

New Scientist: Jeppe Seidelin Dam and colleagues at the Technical University of Denmark in Roskilde are developing a device that can convert IR radiation into visible light. Attached to a digital camera fitted with an IR flash, it could detect tumors by recording the telltale pattern of IR light they reflect. "This would allow a surgeon to quickly determine if the entire tumor has been removed before finishing an operation," he says. Their results have been published in Optics Letters.

New York Times: Congressman Edward Markey (D-MA) has complained to the Nuclear Regulatory Commission that its radiation safety rules are less stringent for human patients than they are for animal patients. At issue is the in-patient recovery time for people and pets who receive radiation therapy for thyroid disease. During and after the treatment, the patients emit radioactivity, which can be harmful to children and pregnant women. Whereas pets are required to stay at the animal hospital for several days, humans are dismissed on the day of the treatment—even though they typically receive much higher radiation doses than pets do.

NPR: A company in South Africa has developed the ability to manufacture molybdenum-99 from low-enriched uranium. The innovation is important for two reasons. First, ⁹⁹Mo decays into another isotope, technetium-99m, which emits 140-keV gamma rays with a half-life of 6 hours. Those two properties make ^99mTc a useful medical tracer. Before the South African source came online, the US supply of ⁹⁹Mo came from just two sources, in Canada and the Netherlands. The Canadian and Dutch sources make ⁹⁹Mo from highly enriched uranium, which accounts for the second reason for the new, South African source's importance: decreased risk that terrorists could get their hands on the raw material for making a nuclear weapon.

Ecoseed: Scientists at the University of Missouri used cinnamon to replace almost all the toxic chemicals needed for making gold nanoparticles. They mixed gold salts with cinnamon and stirred the mixture in water. Kattesh Katti, professor of radiology and physics in the School of Medicine and the College of Arts and Science, said the process is environmentally friendly because it uses no electricity and utilizes no other toxic chemicals. Gold nanoparticles are used in electronics and healthcare. Katti uses his for cancer treatment, which was the focus of his study published in Pharmaceutical Research.

Nature: Researchers at Harvard Medical School believe they are a step closer to reversing the aging process after rejuvenating worn-out organs in elderly mice. They found that premature aging can be reversed by reactivating an enzyme—telomerase—that protects the tips of chromosomes. It is possible that normal human aging could be slowed by reawakening the enzyme in cells where it has stopped working, according to Ronald DePinho, a cancer geneticist at the Dana-Farber Cancer Institute and Harvard Medical School in Boston, Massachusetts, who led the new study. "This has implications for thinking about telomerase as a serious anti-aging intervention," he said.

Baltimore Sun: Reminiscent of the 2004 film Eternal Sunshine of the Spotless Mind, researchers say that someday it may be possible to selectively erase memories. Richard L. Huganir, professor and chair of neuroscience in the John Hopkins School of Medicine, and colleagues—who performed their experiments on mice, the results of which have been published in Science—claim that proteins can be removed from the brain's fear center to erase memories forever. Such therapy could help treat pain or drug abuse, or erase memories for people suffering from post-traumatic stress syndrome. Critics have raised ethical and practical questions, however. Kate Farinholt, executive director of the mental health support and information group NAMI Maryland, asks, “How do you remove a memory without removing a whole part of someone's life, and is it best to do that, considering that people grow and learn from their experiences."

BBC: Some people are unable to lower their blood pressure to healthy levels by taking diuretics, ACE inhibitors, or other antihypertensive drugs. Now, as the BBC's Michelle Roberts reports, radiation therapy might provide an alternative. Murray Esler of the Baker IDI Heart and Diabetes Institute in Melbourne, Australia, and his collaborators have found that radio waves, when directed at the kidney via a catheter, destroy certain nerves that would otherwise signal blood vessels to constrict. The reduction in systolic blood pressure observed in trials is a modest 10 mmHg, but it was achieved without apparent side effects.

Washington Post: David Mann of the University of South Florida and his collaborators have adapted a technique used to test the hearing of infants and applied it to beached or stranded dolphins. By measuring the electrical impulses evoked by an auditory stimulus, Mann and his team discovered that some beached or stranded dolphins are deaf. As the researchers report in a paper in PLoS One, the deafness appears to depend on species:

Approximately 57% of the bottlenose dolphins and 36% of the rough-toothed dolphins had significant hearing deficits with a reduction in sensitivity equivalent to severe (70–90 dB) or profound (>90 dB) hearing loss in humans. The only stranded short-finned pilot whale examined had profound hearing loss. No impairments were detected in seven Risso's dolphins from three different stranding events, two pygmy killer whales, one Atlantic spotted dolphin, one spinner dolphin, or a juvenile Gervais' beaked whale.

Mann notes there are five possible causes of hearing loss in dolphins: intense chronic noise, transient intense noise, age-related hearing loss, congenital hearing impairment, and the side effects of certain antibiotics that are given to sick, stranded dolphins. Because dolphins rely on hearing to find food, Mann argues "that hearing screening should be part of the standard veterinary examination of stranded cetaceans." A deaf dolphin, even if it recovers from being stranded, is unlikely to fare well when returned to the sea.

NPR: By the end of next year, one out of every six airline passengers at US airports will be asked to go through a scanner that uses backscattered x rays to find concealed weapons. In absolute terms, the radiation dose delivered to each passenger in one scan is tiny: 0.02 microsieverts, about 1/1000th of the dose the same passenger would receive from cosmic rays during a transcontinental flight. But, as NPR's Richard Knox reported earlier this year, a group of biochemists and biophysicists from the University of California, San Francisco, has challenged the assumption that the scanners are safe, despite the low dose. The scientists question whether the prime safety criterion should be the overall dose, if, as they suspect, the dose is concentrated in the passenger's skin.

SPACE.com: New research shows that not only does space travel weaken bones but the effects can last for a year or more after astronauts return to Earth. Humans develop strong bones particularly in their hips and legs due to Earth’s gravity. Study leader Shreyasee Amin, an associate professor at the Mayo Clinic in Minnesota, and colleagues have found that in the microgravity of space those bones in particular tend to become weaker and remain weaker for some time even after the astronauts landed back on Earth. Amin and colleagues present their results today at the American College of Rheumatology annual scientific meeting in Atlanta.

Nature: Daniel Zalko of the French National Institute for Agricultural Research in Paris and his colleagues have used radioactive tracers to prove that bisphenol A (BPA) is readily absorbed through the skin. The chemical, which is widely used as an additive in plastics and other consumer products, has been banned in Canada because of its implication in a range of medical conditions, including birth defects. Zalko and company's findings might help clear up a mystery. Some people have higher levels of BPA in their bodies than would be expected if they ingested it in food or drink. Among the BPA-containing products that people routinely touch is the thermal paper used for store receipts.

New Scientist: Researchers at the University of Oxford report in Current Biology that applying an electric current to a particular area of the human brain can improve mathematical abilities for at least six months. Roi Cohen Kadosh’s team applied transcranial direct current stimulation to the right parietal cortex while simultaneously using the opposite current to subdue activity in the left parietal cortex. "This isn't going to turn you into a genius," said Cohen Kadosh, "but it could be turned into a device to help children with poor numeracy skills improve their mathematical abilities."

BBC: A collaboration between the University of Tübingen and Retina Implant AG—both in Germany—has successfully tested a chip that, once installed behind a damaged retina, can partially restore a blind person's sight. As the BBC's Neil Bowdler explains, the sub-retinal chip works like an undamaged retina. Light focused by the eye's lens strikes the chip, which converts the energy into electrical impulses and sends them to the optic nerve.

SPACE.com: Genomics pioneer J. Craig Venter asserts that human space exploration could benefit from more genetic screening and genetic engineering. Genetic screening could help better identify individuals most suited for long space missions, by identifying certain genes that would be desirable, such as ones that encode robust bone regeneration or rapid repair of DNA. Genetic engineering could make space travel safer and more efficient, by engineering microbes to help astronauts take up nutrients more efficiently or to eliminate body odor, for example. However, engineering humans would only come after long consideration and debate, Venter said.

BBC: In a paper in the latest issue of Nature, Caltech's Moran Cerf and his collaborators report experiments that directly probed how our imaginations can shape, and even override, what our senses tell us. Cerf's team looked at the output from detectors attached to single neurons in the brains of 12 epilepsy patients. The patients were shown hybrid images of actors Josh Brolin and Marilyn Monroe and asked to "see" one or the other—that is, to mentally change what was before their eyes. Having already determined which neurons hold either image, Cerf and his team could tell that the patients could reliably override the hybrid image and "see" the image of the requested actor. According to Cerf, his findings suggest that it might be possible one day to record people's dreams.

Science: A new robotic hand that has no fingers is being developed by Eric Brown (University of Chicago) and colleagues, who published their findings in the Proceedings of the National Academy of Sciences. When their hand—a rubber sack filled with coffee grains or small glass spheres, like a beanbag—comes in contact with an object, a pipe sucks air from the sack, causing it to contract and mold to the object’s shape. So far, the prototype has been able to perform such tasks as pouring water and using a pen. It holds great promise for amputees because it would be much easier to operate than the more complex prosthetic hands currently available.

Science News: Scientists at the Johns Hopkins University have created millimeter-sized machines that operate without batteries or any other source of power. Engineer David Gracias and coworkers, who published their results in the Journal of the American Chemical Society, developed the tiny tools, which have five finger-like extensions that snap shut when exposed to a certain chemical or combination of chemicals. Their invention could have medical applications such as to biopsy tiny bits of tissue or to deliver small amounts of drugs to disease sites in the body.

CNET News: A mini-atom-based magnetic sensor has successfully tracked a human heartbeat, say physicists at NIST, who are working with researchers at a German national metrology institute. A key advantage, says principal investigator John Kitching, is that the magnetic signals detected by magnetocardiograms aren't affected by fluids in the body, as are the electric signals used with electrocardiograms; MCGs also do not require contact with the body. Nevertheless, such a device would require powerful shielding from Earth's magnetic field. Kitching and coworkers have published their findings in Applied Physics Letters.

New Scientist: Researchers led by Derrick Rossi of the Children's Hospital Boston have created induced pluripotent stem cells (iPSCs) from adult skin cells; the resulting iPSCs have the same capacity as primordial embryonic stem cells to turn into almost every tissue of the body, but don’t involve the use of embryos. The group’s research was published in the journal Cell Stem Cell. Robert Lanza, chief scientific officer at Advanced Cell Technology in Worcester, Massachusetts, called it a game-changer. "If repeatable, it would solve some of the most important problems in the field," he said. The announcement comes as the future of federal funding for embryonic stem-cell research hangs in doubt.

New York Times: The three-dimensional imaging techniques of the movies are being used to improve athletic performance. Motion capture produces a 3D image on a computer using a combination of advanced sensors, biomechanics, orthopedic research, and animated-film technology such as that used in the film Avatar (2009). The images generated, which can be viewed from any direction, provide a wealth of data regarding limb angles, ball speeds, and g-forces. Some of the innovative uses of the new technology include sports players studying their peak performances to improve their technique and avoid injury, dancers in different locations being able to practice with each other using 3D re-creations, and coaches working remotely with teams by watching them perform drills in three dimensions in another location.

Science: A three-judge panel of the US Court of Appeals for the District of Columbia, which had on 9 September lifted a judge’s ban on stem-cell research, has now decided to allow federal funding for human embryonic stem-cell research to continue while the court considers a judge’s decision that such research is illegal. US District Judge Royce C. Lamberth had ruled in August that a 14-year-old congressional spending restriction prohibited federal support for all research on embryonic stem cells. The National Institutes of Health, however, maintains that the restriction prohibits for research purposes only the creation of embryos, not the use of existing embryos. It could take more than a year for the legal case to be resolved.

Daily Mail: Researchers at the University of California, Berkeley, have developed a touch-sensitive artificial "skin"—dubbed "e-skin"—made of thin flexible material embedded with inorganic semiconductor nanowires. According to Ali Javey, head of the Berkeley research team, ''The idea is to have a material that functions like the human skin, which means incorporating the ability to feel and touch objects." The material could be used on robots and perhaps even on humans with artificial limbs, which would require more sophisticated techniques involving integration of electronic sensors with the human nervous system. The group has published its findings in Nature Materials.

Daily Mail: A new laser machine that vaporizes lung tumors was introduced this year at the Royal Brompton Hospital in London. The machine—which fires 70 kilowatts of energy per square centimeter, the equivalent power of 70 microwave ovens—is most often used on secondary tumors, because they are smaller and more numerous, and because primary tumors usually require more of the lung be removed. According to George Ladas, the hospital's leading thoracic surgeon, the new method means patients are under general anesthetic for about half the time of the old operating method, operating times and hospital stays are reduced, and patients recover faster.

Los Angeles Times: An appeals court in Washington, DC, ruled yesterday that the National Institutes of Health may temporarily resume funding research that involves human embryonic stem cells. NIH had halted research last month in response to a court-ordered injunction that stated that federal funds cannot be used for such purposes. "We are pleased with the court's interim ruling, which will allow this important, life-saving research to continue while we present further arguments to the court in the weeks to come," said NIH Director Francis Collins.

Daily Mail: A free iPhone app has been replacing an essential piece of equipment for hundreds of doctors: the stethoscope. To use the app, which is called iStethoscope, one presses the iPhone’s built-in microphone against the bare chest for a few seconds, then gives the device a shake. Its motion sensors and camera capture the heart’s waveform, which is then displayed on the iPhone’s screen. Developed by Peter Bentley at University College London, the iStethoscope can capture a more accurate reading than a simple acoustic stethoscope.

Science: Possibly unprecedented in its history, the National Institutes of Health yesterday ordered a shutdown of human embryonic stem cell experiments by researchers in labs on the NIH campus. According to Jocelyn Kaiser of Science, the message came from NIH intramural research chief Michael Gottesman. The action was a response to a court-ordered injunction a week ago, which stated that using NIH funding to study human embryonic stem cells violates a law prohibiting the use of federal funds to destroy embryos.

Nature: Leo Gross of IBM's research center in Zurich, Switzerland, and his coworkers have used an atomic force microscope (AFM) and a scanning tunneling microscope (STM) to determine the structure of cephalandole A, an organic molecule found in a deep-sea-dwelling bacterium. Cephalandole A contains three six-membered benzene rings and one five-membered pyrrole ring. Four possible structures had previously been identified. As Nature’s Philip Ball reports, Gross and his team immobilized molecules of cephalandole A on a crystal surface, then probed their electronic structure with an STM and their shape with an AFM. Drug companies are interested in cephalandole A. One of its chemical relatives, camptothecin, showed promise as an anticancer drug.

Daily Mail: An implantable miniature telescope has received FDA approval for use in the US.

The device was developed by VisionCare to treat end-stage age-related macular degeneration—when a blind spot develops in the central vision of the eye.

Implanted in the cornea, the device expands an incoming image onto the peripheral parts of the retina that are undamaged from AMD, thereby reducing the blind spot's effect. So far, the device is slated for use in people over the age of 75 and doesn't treat AMD directly; it can only be implanted in one eye, and the patient has to learn how to merge the two images rendered in order to see.

New Scientist: Do suckling babies extract milk by squeezing the nipple like a milkmaid or by sucking from the nipple like a milking machine? Donna Geddes from the University of Western Australia found in favor of sucking after they combined ultrasound movies of suckling infants with measurements of the pressure the babies created as they fed. The results could help solve the problem of why some babies don’t take up breast feeding.

Physics Today: Rice University undergraduates Lila Kerr and Lauren Theis have developed a rudimentary blood centrifuge that does not require electricity, by adapting a standard salad spinner.

symmetry: Business in the particle accelerator world is booming, as is business at Advanced Energy Systems, where Tony Favale is president. His company is doing research and design work for the next generation of accelerators, which will be employed in electron lasers for the Navy, radiation detectors for the Department of Homeland Security, and more efficient particle colliders at US national laboratories.

But of the seven positions he was advertising in November, three were still unfilled in mid-March because Favale can't find enough qualified accelerator scientists.

ABC News: Shahram Amiri, an Iranian nuclear scientist who has been missing since last summer, has defected to the US, reports ABC News.

NYTimes.com: Urgent warnings by government experts about the risks of routinely using powerful CT scans to screen patients for colon cancer were brushed aside by the Food and Drug Administration, according to agency documents and interviews with agency scientists.

After staying quiet for a year, the scientists say they plan to make their concerns public at an FDA meeting to discuss how to protect patients from unnecessary radiation exposure. The two-day meeting is part of a reassessment of the risks of routine radiology. The average lifetime dose of diagnostic radiation has increased sevenfold since 1980, driven in part by the increasing popularity of CT scans. Such scans can deliver the radiation equivalent of 400 chest x rays.

NYTimes.com: Specialists say such safeguards, such as ear muffs at loud stadiums, are critical for young ears in a deafening world. Hearing loss from exposure to loud noises is cumulative and irreversible; if such exposure starts in infancy, children can live “half their lives with hearing loss,” said Brian Fligor, director of diagnostic audiology at Children’s Hospital Boston.

AAAS Meeting: Margaret Murnane and Henry Kapteyn group at JILA, a joint institute of the University of Colorado at Boulder and NIST, has made some breakthroughs on how to build a tabletop x-ray laser. The laser could be used for super high-resolution imaging, while also giving scientists a new way to at the nanoscale at objects such as a single cell.

Murnane and Kapteyn presented highlights of their research at the American Association for the Advancement of Science annual meeting in San Diego.

"Our goal is to create a laser beam that contains a broad range of x-ray wavelengths all at once that can be focused both in time and space," Murnane said. "If we have this source of coherent light that spans a huge region of the electromagnetic spectrum, we would be able to make the highest resolution light-based tabletop microscope in existence that could capture images in 3-D and tell us exactly what we are looking at. We're very close."

Most of today's x-ray lasers require so much power that they rely on fusion laser facilities the size of football stadiums or larger, making their use impractical. Murnane and Kapteyn generate coherent laser-like x-ray beams by using an intense femtosecond laser and combining hundreds or thousands of visible photons together with a desktop-size system.

They can already generate laser-like x-ray beams in the soft x-ray region and believe they have discovered how to extend the process all the way into the hard x-ray region of the electromagnetic spectrum.

"If we can do this, it could lead to all kinds of possibilities," Kapteyn said. "It might make it possible to improve x-ray imaging resolution at your doctor's office by a thousand times. The x-rays we get in the hospital now are limited. For example, they can't detect really small cancers because the x-ray source in your doctor's office is more like a light bulb, not a laser. If you had a bright, focused laser-like x-ray beam, you could image with far higher resolution."

Their method can be thought of as a coherent version of the x-ray tube, according to Murnane. In an x-ray tube, an electron is boiled off a filament, then it is accelerated in an electric field before hitting a solid target, where the kinetic energy of the electron is converted into incoherent x-rays. These incoherent x-rays are like the incoherent light from a light bulb or flashlight—they aren't very focused.

In the tabletop setup, instead of boiling an electron from a filament, they pluck part of the quantum wave function of an electron from an atom using a very intense laser pulse. The electron is then accelerated and slammed back into the ion, releasing its energy as an x-ray photon. Since the laser field controls the motion of the electron, the x-rays emitted can retain the coherence properties of a laser, Murnane said.

Being able to build a tabletop x-ray laser is just the beginning, said Kapteyn.

"An analogy that is pretty close to what is going on in this field is the MRI, which started as just a fundamental investigation," said Kapteyn. "People then started using it for microscopy, and then it progressed into a medical diagnostic technique."

NPR: Doctors use expensive CT scanners and MRI machines thousands of times every day to look for brain damage. But sometimes cheap and simple is definitely better.

The Economist: The great hope of transplant surgeons is that they will, one day, be able to order replacement body parts on demand. That possibility may be closer with the arrival of the first commercial 3D bio-printer for manufacturing human tissue and organs.

The new machine, which costs around $200,000, has been developed by San Diego–based Organovo, a company that specializes in regenerative medicine, and an Australian engineering and automation firm called Invetech.

To start with, only simple tissues, such as skin, muscle, and short stretches of blood vessels, will be made for research purposes.

Organovo expects that within five years, once clinical trials are complete, the printers will produce blood vessels for use as grafts in bypass surgery.

WSJ.com: Scientific revolutions are often led by the youngest scientists, and yet such innovation in the US could be at risk, says Jonah Lehrer in the Wall Street Journal, as the number of successful young scientists is dramatically shrinking.

In 1980, the largest share of grants from the National Institutes of Health went to scientists in their late 30s. By 2006 the curve had been shifted sharply to the right, with the highest proportion of grants going to scientists in their late 40s. This shift came largely at the expense of young scientists.

In 1980, researchers between the ages of 31 and 33 received nearly 10% of all grants; by 2006 they accounted for approximately 1%. And the trend shows no signs of abating: In 2007, the most recent year available, there were more grants to 70-year-old researchers than there were to researchers under the age of 30.

NYTimes.com: Just as the worldwide shortage of technetium 99—radioactive isotope used in millions of medical procedures—is about to get worse, officials say a new source for the substance has emerged: a nuclear reactor in Poland.

NYTimes.com: Americans today receive far more medical radiation than ever before. The average lifetime dose of diagnostic radiation has increased sevenfold since 1980, and more than half of all cancer patients receive radiation therapy. Without a doubt, radiation saves countless lives, and serious accidents are rare.

But patients often know little about the harm that can result when safety rules are violated and ever more powerful and technologically complex machines go awry. To better understand those risks, the New York Times has examined thousands of pages of public and private records and interviewed physicians, medical physicists, researchers and government regulators.

It found that while this new technology allows doctors to more accurately attack tumors and reduce certain mistakes, its complexity has created new avenues for error—through software flaws, faulty programming, poor safety procedures, or inadequate staffing and training. When those errors occur, they can be crippling.

New Scientist: Canada is one of the world's biggest suppliers of radioactive isotopes for medical use through an aging 50-year-old reactor based at Chalk River in Ontario.

Two brand-new reactors, constructed on the same site for more than Can$350 million ($330 million), called MAPLE 1 and MAPLE 2 were built as replacements.

But the sad truth is that the MAPLEs have never been officially switched on, and the chances are they never will be.

This has led to a furious row over who is to blame for this costly and embarrassing debacle.

Many in the nuclear industry point the finger at Canada's nuclear regulator. The regulator's view is that the reactors' manufacturer failed to deliver a crucial safety feature that it had promised would underpin the design.

Others blame the Canadian government for killing off the project before crucial technical questions had been resolved.

Alison Motluk takes a look at the technical difficulties faced by the reactors, why the Canadian government shut them down, and why it is building a billion-dollar replacement.

Nature News: The US Department of Energy should build two dedicated isotope-production facilities, costing about $65 million in total, to solve worsening supply problems for researchers in medicine, physical sciences, and national security. That's the conclusion from a panel convened by the energy department's Nuclear Science Advisory Committee (NSAC).

Various: A new study from the National Cancer Institute projects 29 000 excess cancers from the 72 million CT scans that Americans got in 2007 alone. Nearly 15 000 of those cancers could be fatal.

It has been known for sometime that doctors had been overprescribing the number of CT scans for their patients, but this is one of the first comprehensive studies in the US that has quantified the risk using actual medical data.

Richard Knox at NPR reports that one of the reasons for the large number of scans is because doctors have been seduced by the high-resolution images CT scans produce, and have not considered the risk to the patient of using high-intensity x rays.

"Physicians [and their patients] cannot be complacent about the hazards of radiation or we risk creating a public health time bomb," said Rita Redberg, editor of Archives of Internal Medicine, which published the paper.

Children, younger adults and women are especially susceptible. Two-thirds of the excess cancers will occur in women, the NCI researchers say.

Projected Future Cancers Possibly Related To CT Scans In U.S.

The bars in the chart above indicate the projected average number of future cancers for each age range (95% uncertainty limits) that could be related to 2007 CT scans performed in the US, according to age at exposure. The lower and upper values represent the possible margin of error from the mean estimate.

"Although a guiding principle in medicine is to ensure that the benefit of a procedure or therapy outweighs the risk, the explosion of CT scans in the past decade has outpaced evidence of their benefit," said Redberg.

Related Links
Projected cancer risks from computed tomographic scans performed in the United States in 2007
Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer
Radiation from CT scans may raise cancer risk NPR
CT scans may pose higher risk of cancer than first thought The Daily Telegraph
Overuse of CT scans will lead to new cancer deaths, a study shows The Los Angeles Times

Times Online: Last year John Gurney was told he had prostate cancer.

His specialist suggested a wait-and-watch approach. But at the age of 67, and with the prospect of having to live with the disease for years, Gurney decided that the uncertainty was going to be less bearable than surgery. "Everyone I had met said it wasn't going to kill me till I was 80, but if you are waiting around like that you want to do something. I had to get on the robot."

The robot in question is the $2 million da Vinci Surgical System, and one Monday a few weeks back, John Gurney got on it—or more precisely was maneuvered under it.

Urologist surgeon's who use robots are finding that up to 50% of their surgeries are now with the device, and 40% of the remaining are laparoscopic operations using small incisions, cameras and probes. The robots limit back pain, a common complaint among surgeon's who carry out prostate surgery.

The da Vinci is a spider-like unit the size of a double fridge, with overhanging mechanical joints wrapped in transparent sheeting.

The surgeon marked out four small incisions on Gurney's stomach and after using his scalpel "for the first and only time", started screwing a camera port into place.

Justin Vale, consultant urologist and pre-eminent robotic surgeon, said that the advantage is that you can pull things in and out easily.

Within a few minutes, two robotic arms were busying away removing John Gurney's prostate.

Backreaction: The Heidelberg Ion-Beam Therapy Center (HIT)—the first medical heavy-ion machine in Europe—has opened.

Close to the GSI facility near Darmstadt, the Heidelberg Ion-Beam Therapy Center is a dedicated heavy-ion accelerator for deployment in radiotherapy to treat tumors.

Treatment center at the focus of the HIT Gantry. Credit: HIT

Physicist Stefan Scherer briefly takes a look at this new facility and the physics behind it.

latimes.com: Three federal agencies—the Food and Drug Administration, the Defense Department, and the National Eye Institute—announced last week that they are launching a three-year effort to gauge how many, and which, patients suffer troubling symptoms after undergoing the vision correction procedure called Lasik.

Physics Today: Batteries can power anything from small sensors to large systems. University of Missouri researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

"To provide enough power, we need certain methods with high energy density," said Jae Kwon, assistant professor of electrical and computer engineering at MU. The radioisotope battery can provide power density that is six orders of magnitude higher than chemical batteries.

Kwon and his research team have been working on building a small nuclear battery, currently the size and thickness of a penny, intended to power various micro/nanoelectromechanical systems. Although nuclear batteries can pose concerns, they are safe are already powering a variety of devices, such as pace-makers, space satellites and underwater systems.

Kwon's innovation is not only in the battery's size, but also in its semiconductor. Kwons battery uses a liquid semiconductor rather than a solid semiconductor.

The critical part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure of the solid semiconductor, said Kwon. By using a liquid semiconductor, we believe we can minimize that problem.

Kwon has been collaborating with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, and is working to build and test the battery at the facility.

In the future, they hope to increase the battery's power, shrink its size and try with various other materials. Kwon said that the battery could be thinner than the thickness of human hair.

NYTimes.com: Two cases involving CT scans are under scrutiny in California—one involving a large, well-known Los Angeles hospital, the other a tiny hospital in the northern part of the state—underscoring the risks that powerful CT scans pose when used incorrectly.

Raven Knickerbocker, then an X-ray technologist at Mad River Community Hospital in Arcata, activated a CT scan 151 times on the same area of the head of 2 ½-year-old Jacoby Roth, investigators concluded.

A week ago, Cedars-Sinai Medical Center in Los Angeles disclosed that it had mistakenly administered up to eight times the normal radiation dose to 206 possible stroke victims over an 18-month period during a procedure intended to get clearer images of the brain.

Although CT scans are useful in determining internal injuries, there are major risks associated to patients because of the intensity of the X-rays used in the device, either through human error, or through too frequent exposure to X-rays.

In 2000-2001, CT scans constituted 7% of all radiologic examinations, but contributed 47% of the total collective dose from medical X-ray examinations.

BBC News: Scientists in Italy think they may have come up with a new way to scan for cancer of the stomach or colon.

The "spider pill," which is fitted with a camera, is swallowed by the patient and once within the colon or intestine the legs are opened and the device crawls along the intestinal tract, taking pictures as it goes.

The Economist: Dialysis is an unpleasant process that involves being hooked up to a huge machine—often at a hospital—at least three times a week, in order to have your blood cleansed of waste that would normally be voided, via the kidneys, as urine.

Victor Gura, of the University of California, Los Angeles, hopes to make this process more pleasant with an invention that is now undergoing clinical trials. By going back to basics, he has come up with a completely new sort of dialyser—one you can wear.

At the heart of the machine is a lightweight pump. The pump drives blood from a patient through a hollow fiber filter as well as water containing some minerals. The water is constantly purified by circulating through chemicals that capture the blood's impurities. The blood is then pumped back to the patient. The filter needs to be replaced about once a week and the chemicals once a day.

In clinical trials reported in the 15 December 2007 issue of the medical journal Lancet, five men and three women with end-stage kidney failure successfully dialyzed themselves with Gura's prototype device for up to eight hours.

Related Links
A wearable artificial kidney for patients on the go UCLA news
Some related publications
A wearable haemodialysis device for patients with end-stage renal failure: a pilot study The Lancet

IEEE Spectrum: The human eye is a perceptual powerhouse. It can see millions of colors, adjust easily to shifting light conditions, and transmit information to the brain at a rate exceeding that of a high-speed Internet connection.

But why stop there?

In the Terminator movies, Arnold Schwarzenegger's character sees the world with data superimposed on his visual field--virtual captions that enhance the cyborg's scan of a scene. In Rainbows End by the science fiction author Vernor Vinge, characters rely on electronic contact lenses, rather than smartphones or brain implants, for seamless access to information that appears right before their eyes.

"These visions might seem far-fetched, but a contact lens with simple built-in electronics is already within reach," says Babak A. Parviz.

"In fact, my students and I are already producing such devices in small numbers in my laboratory at the University of Washington, in Seattle. These lenses don't give us the vision of an eagle or the benefit of running subtitles on our surroundings yet. But we have built a lens with one LED, which we've powered wirelessly with RF. What we've done so far barely hints at what will soon be possible with this technology."

CNET News: New research being developed at Lawrence Livermore National Laboratory, could reduce the size of proton accelerator machines from that of a football field to that of a traditional X-ray machine.

The smaller size and cost could increase the availability of proton therapy treatments.

Related Link
Electromagnetic and Thermal Simulations for the Switch Region of a Compact Proton Accelerator

2009 AIP Industrial Physics Forum: Developments from CERN could make CT scanners even better at detecting early cancer cells or other disease indicators.

The particle physics research laboratory's work to create photon counters that can count ten million photons per second—up by a factor of one hundred from previous generation counters—have been integrated into CT systems and had their first trial run with patients. There are more developments that will have to take place before the photon-counters can fullfill their full potential, but early work presented at the recent AAPM meeting looks promising.

While CERN made the progress in photon counter technology, it has been representatives from industry who put them together with CT scanners. At the AIP and AAPM meeting, Reuven Levinson, a Technology Development Leader at GE Healthcare in the CT Engineering group in Haifa, Israel, announced the first use of a photon counting CT system on human patients. The CT's X-ray detector counts the individual photons and measures their energy. Levinson and his team built the photon counting CT system and had it installed last year at the Rabin Medical Center in Tel Aviv, Israel.

2009 AIP Industrial Physics Forum: It took scientists more than twenty years after the first DNA sequencing technology was discovered to sequence the entire human genome; yet our own cells complete this task every time our bodies produces a daughter cell.

So to achieve the goal of real time DNA sequencing, Pacific Biosciences had the idea to spy on Mother Nature as she goes to work copying DNA. Now, the company's commercial device planned to be on the market in 2010, promises to be 20,000 times faster than current second generation technology, with turn around time of about ten minutes rather than ten days.

Chief Technology Officer Steve Turner says in four to five years, new technologies promise to rocket this technology forward even further, making it will possible to sequence an entire human genome in fifteen minutes, on a chip that costs less than 100 dollars

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.

Physics Today: A new $120 million proton therapy center opened in Oklahoma City two weeks ago. It is only the sixth proton treatment center in the US and will treat approximately 1500 patients a year.

The 18,300 m² facility is a joint project between ProCure Treatment Centers, Inc, a four-year-old start-up company; Radiation Medicine Associates, one of the state's leading radiation oncology practices; and INTEGRIS Health, the state's largest Oklahoma-owned, not-for-profit healthcare corporation, which will offer ancillary care to patients that need it.

ProCure is currently building a US network of proton therapy centers, the second of which will be in Chicago, followed by locations in New Jersey, Detroit and South Florida.

Proton therapy is attractive to physicians because for some types of cancers, the higher doses of radiation can be used to control and manage cancer while significantly reducing damage to healthy tissue and vital organs that occur with more traditional radiation treatment.

The Oklahoma center was built in 27 months and makes use of a number of new innovations, such as the design of the treatment room, and the uses of robotic patient positioning systems to bring the cost of treatment down by a significant margin. The protons are created through use of a 220-ton cyclotron that is 5.4-meters in diameter and 2.4 meters high (see above. Photo credit: ProCure Treatment Centers).

"Right now, there are only about 6,000 treatment slots available in the United States for a quarter of a million cancer patients who are candidates for proton therapy," said Procure's CEO Hadley Ford.

Ford acknowledged that energy executive and philanthropist Aubrey K. McClendon, co-founder, chairman, and CEO of Oklahoma City-based Chesapeake Energy Corporation, personally provided the initial $70 million funding for ProCure. "ProCure's vision to make proton therapy more accessible to cancer patients caught my attention three years ago," says McClendon. "The company has done an exceptional job developing and constructing this facility since that time."

"Oklahoma City's proton center is the realization of what was not much more than a dream four years ago," said Procure's founder, physicist John Cameron (left) at the opening ceremony.

Cameron survived a bout of prostate cancer through proton therapy four years ago. "Many are talking about building proton centers; we're actually doing it," he says. "These are very exciting times for us and for patients with cancer."

"The nature of the proton therapy—a daily course of treatment that can last for up to eight weeks—argues for more centers in many more communities," said W.C. Goad, medical director of the new center. "In every center in the country, half or more of the patients treated come from out of state."

Related Physics Today articles
Accelerators shrink to meet growing demand for proton therapy March 2009
Weighing Proton Therapy's Clinical Readiness and Costs June 2003

Nature News: The worldwide shortage of medical isotopes is about to get much worse this week, as the High Flux Reactor in Petten, the Netherlands, closes for a month-long maintenance inspection.

It joins the National Research Universal reactor in Chalk River, Ontario, Canada, which has been closed since 15 May because of a heavy-water leak and is unlikely to restart before late 2009, according to Atomic Energy of Canada Limited, the government-sponsored body that runs the facility.

Related News Picks
Europe's isotope shortage will continue into 2009
Isotope shortage could delay cancer treatments
Canada pulls plug on costly medical reactor plan

Science News: Undergoing a virtual colonoscopy might be just the ticket for people at high risk of colorectal cancer who need screening every few years, a new study finds. By spotting 85 percent of polyps, computed tomography scans offer a way to detect the precancerous growths in a way that is less invasive than a conventional colonoscopy, a European team of researchers reports in the 17 June Journal of the American Medical Association.

Related Link
Diagnostic Accuracy of Computed Tomographic Colonography for the Detection of Advanced Neoplasia in Individuals at Increased Risk of Colorectal Cancer

Science: Pacemakers and bionic ears (cochlear implants) were the first medical bionic devices to be used successfully in humans.

On the horizon there is the prospect of a neural prosthesis capable of operating prosthetic limbs, a bionic eye, as well as other devices for the restoration of body function.

These developments are crucially dependent on successfully connecting the device to cellular tissue. The development of organic polymer conductors is contributing to achieving that success.

Related Physics Today articles
Sound Research Aids the Deaf April 2006
Cochlear Implants: Fundamentals and Applications November 2004

Nature: Optical imaging routinely uses multicoloured contrast agents ranging from traditional chemical dyes and fluorophores to specially engineered quantum dots. In magnetic resonance imaging (MRI), contrast agents have also proved extremely useful, but their effects are largely indistinguishable from one another, leading to essentially monochrome contrast based on increased or decreased signal strength. Gary Zabow Stephen Dodd, John Moreland & Alan Koretsky are bringing 'colour' to MRI. They have developed an approach to produce MRI contrast agents with characteristic spectral signals, based on the control of mechanical structures. Different versions of these probes can be used simultaneously, and are distinguishable by the geometry-dependent spectral 'colour' of their signals.

Related article
Micro-engineered local field control for high-sensitivity multispectral MRI (Nature 453, 1058-1063)