A search for quantum computers led to a medical aplication. One day we may get MRI-like devices that can probe individual drug molecules and living cells.
K.S.Parthasarathy
Public release date: 22-Sep-2009
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Contact: Chad Boutin
boutin@nist.gov
301-975-4261
National Institute of Standards and Technology (NIST)
Diamonds may be the ultimate MRI probe, say Quantum physicists
Diamonds, it has long been said, are a girl's best friend. But a research team including a physicist from the National Institute of Standards and Technology (NIST) has recently found* that the gems might turn out to be a patient's best friend as well.
The team's work has the long-term goal of developing quantum computers, but it has borne fruit that may have more immediate application in medical science. Their finding that a candidate "quantum bit" has great sensitivity to magnetic fields hints that MRI-like devices that can probe individual drug molecules and living cells may be possible.
The candidate system, formed from a nitrogen atom lodged within a diamond crystal, is promising not only because it can sense atomic-scale variations in magnetism, but also because it functions at room temperature. Most other such devices used either in quantum computation or for magnetic sensing must be cooled to nearly absolute zero to operate, making it difficult to place them near live tissue. However, using the nitrogen as a sensor or switch could sidestep that limitation.
Diamond, which is formed of pure carbon, occasionally has minute imperfections within its crystalline lattice. A common impurity is a "nitrogen vacancy", in which two carbon atoms are replaced by a single atom of nitrogen, leaving the other carbon atom's space vacant. Nitrogen vacancies are in part responsible for diamond's famed luster, for they are actually fluorescent: when green light strikes them, the nitrogen atom's two excitable unpaired electrons glow a brilliant red.
The team can use slight variations in this fluorescence to determine the magnetic spin of a single electron in the nitrogen. Spin is a quantum property that has a value of either "up" or "down," and therefore could represent one or zero in binary computation. The team's recent achievement was to transfer this quantum information repeatedly between the nitrogen electron and the nuclei of adjacent carbon atoms, forming a small circuit capable of logic operations. Reading a quantum bit's spin information—a fundamental task for a quantum computer—has been a daunting challenge, but the team demonstrated that by transferring the information back and forth between the electron and the nuclei, the information could be amplified, making it much easier to read.
Still, NIST theoretical physicist Jacob Taylor said the findings are "evolutionary, not revolutionary" for the quantum computing field and that the medical world may reap practical benefits from the discovery long before a working quantum computer is built. He envisions diamond-tipped sensors performing magnetic resonance tests on individual cells within the body, or on single molecules drug companies want to investigate—a sort of MRI scanner for the microscopic. "That's commonly thought not to be possible because in both of these cases the magnetic fields are so small," Taylor says. "But this technique has very low toxicity and can be done at room temperature. It could potentially look inside a single cell and allow us to visualize what's happening in different spots."
The Harvard University-based team also includes scientists from the Joint Quantum Institute (a partnership of NIST and the University of Maryland), the Massachusetts Institute of Technology and Texas A&M University.
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* L. Jiang, J.S. Hodges, J.R. Maze, P. Maurer, J.M. Taylor, D.G. Cory, P.R. Hemmer, R.L. Walsworth, A. Yacoby, A.S. Zibrov and M.D. Lukin. Repetitive readout of a single electronic spin via quantum logic with nuclear spin ancillae. Science, DOI: 10.1126/science.1176496, published online Sept. 10, 2009.
See http://www.nist.gov/public_affairs/techbeat/tb2009_0922.htm#diamonds for illustration to accompany story.
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Showing posts with label MRI image. Show all posts
Showing posts with label MRI image. Show all posts
Wednesday, September 23, 2009
Tuesday, November 27, 2007
Secondhand smoke damages lungs, MRIs show
Researchers use MRI scanner to image damage in the lung due to second-hand smoke.They presented this work at RSNA 2007
K.S.Parthasarathy
Public release date: 26-Nov-2007
Contact: Rachel Salis-Silverman
Salis@email.chop.edu
267-426-6063
Children's Hospital of Philadelphia
Secondhand smoke damages lungs, MRIs show
The apparent diffusion coefficient (ADC) measures lung injury, indicated by different colors.
Click here for more information.
It’s not a smoking gun, but it’s smoking-related, and it’s there in bright medical images: evidence of microscopic structural damage deep in the lungs, caused by secondhand cigarette smoke. For the first time, researchers have identified lung injury to nonsmokers that was long suspected, but not previously detectable with medical imaging tools.
The researchers suggest that their findings may strengthen public health efforts to restrict secondhand smoke.
“We used a special type of magnetic resonance imaging to find these structural changes in the lungs,” said study leader Chengbo Wang, Ph.D., a magnetic resonance physicist in the Department of Radiology at The Children’s Hospital of Philadelphia. “Almost one-third of nonsmokers who had been exposed to secondhand cigarette smoke for a long time developed these structural changes.” Formerly at the University of Virginia, Wang collaborated with radiology researchers at that institution, where they acquired the MRIs from adult smokers and nonsmokers.
Wang presented the team’s findings in Chicago at the annual meeting of the Radiological Society of North America. Although the participants in the research study were adults, Wang said the results have implications for the 35 percent of American children who live in homes where regular smoking occurs.
The researchers studied 60 adults between ages 41 and 79, 45 of whom had never smoked. The 45 non-smokers were divided into groups with low and high exposure to secondhand smoke; the high-exposure subjects had lived with a smoker for at least 10 years, often during childhood. The 15 current or former smokers formed a positive control group.
The research team prepared an isotope of helium called helium-3 by polarizing it to make it more visible in the MRI. Researchers diluted the helium in nitrogen and had research subjects inhale the mixture. Unlike ordinary MRIs, this MRI machine measured diffusion, the movement of helium atoms, over 1.5 seconds. The helium atoms moved a greater distance than in the lungs of normal subjects, indicating the presence of holes and expanded spaces within the alveoli, tiny sacs within the lungs.
The researchers found that almost one-third of the non-smokers with high exposure to secondhand smoke had structural changes in their lungs similar to those found in the smokers. “We interpreted those changes as early signs of lung damage, representing very mild forms of emphysema,” said Wang. Emphysema, a lung disease that is a major cause of death in the U.S., is commonly found in heavy smokers.
The researchers also found a seemingly paradoxical result among two-thirds of the high-exposure group of non-smokers—diffusion measurements that were lower than those found in the low-exposure group. Although these findings require more study, said Wang, they may reflect a narrowing in airways caused by early stages of another lung disease, chronic bronchitis.
“To our knowledge, this is the first imaging study to find lung damage in non-smokers heavily exposed to secondhand smoke,” said Wang. “We hope our work strengthens the efforts of legislators and policymakers to limit public exposure to secondhand smoke.”
###
The study received financial support from the National Heart, Lung and Blood Institute, the Flight Attendant Medical Research Institute, the Commonwealth of Virginia Technology Research Fund, and Siemens Medical Solutions.
Wang’s co-authors were Talissa A. Altes, M.D., and Kai Ruppert, Ph.D., now of the Children’s Hospital Radiology Department; and G. Wilson Miller, Ph.D., Eduard E. deLange, M.D., Jaime F. Mata, Ph.D., Gordon D. Cates, Jr., Ph.D., and John P. Mugler III, Ph.D., all of the University of Virginia Department of Radiology. Drs. Wang, Altes, and Ruppert were previously at the University of Virginia as well.
About The Children's Hospital of Philadelphia: The Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals and pioneering major research initiatives, Children's Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country, ranking third in National Institutes of Health funding. In addition, its unique family-centered care and public service programs have brought the 430-bed hospital recognition as a leading advocate for children and adolescents. For more information, visit http://www.chop.edu.
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K.S.Parthasarathy
Public release date: 26-Nov-2007
Contact: Rachel Salis-Silverman
Salis@email.chop.edu
267-426-6063
Children's Hospital of Philadelphia
Secondhand smoke damages lungs, MRIs show
The apparent diffusion coefficient (ADC) measures lung injury, indicated by different colors.
Click here for more information.
It’s not a smoking gun, but it’s smoking-related, and it’s there in bright medical images: evidence of microscopic structural damage deep in the lungs, caused by secondhand cigarette smoke. For the first time, researchers have identified lung injury to nonsmokers that was long suspected, but not previously detectable with medical imaging tools.
The researchers suggest that their findings may strengthen public health efforts to restrict secondhand smoke.
“We used a special type of magnetic resonance imaging to find these structural changes in the lungs,” said study leader Chengbo Wang, Ph.D., a magnetic resonance physicist in the Department of Radiology at The Children’s Hospital of Philadelphia. “Almost one-third of nonsmokers who had been exposed to secondhand cigarette smoke for a long time developed these structural changes.” Formerly at the University of Virginia, Wang collaborated with radiology researchers at that institution, where they acquired the MRIs from adult smokers and nonsmokers.
Wang presented the team’s findings in Chicago at the annual meeting of the Radiological Society of North America. Although the participants in the research study were adults, Wang said the results have implications for the 35 percent of American children who live in homes where regular smoking occurs.
The researchers studied 60 adults between ages 41 and 79, 45 of whom had never smoked. The 45 non-smokers were divided into groups with low and high exposure to secondhand smoke; the high-exposure subjects had lived with a smoker for at least 10 years, often during childhood. The 15 current or former smokers formed a positive control group.
The research team prepared an isotope of helium called helium-3 by polarizing it to make it more visible in the MRI. Researchers diluted the helium in nitrogen and had research subjects inhale the mixture. Unlike ordinary MRIs, this MRI machine measured diffusion, the movement of helium atoms, over 1.5 seconds. The helium atoms moved a greater distance than in the lungs of normal subjects, indicating the presence of holes and expanded spaces within the alveoli, tiny sacs within the lungs.
The researchers found that almost one-third of the non-smokers with high exposure to secondhand smoke had structural changes in their lungs similar to those found in the smokers. “We interpreted those changes as early signs of lung damage, representing very mild forms of emphysema,” said Wang. Emphysema, a lung disease that is a major cause of death in the U.S., is commonly found in heavy smokers.
The researchers also found a seemingly paradoxical result among two-thirds of the high-exposure group of non-smokers—diffusion measurements that were lower than those found in the low-exposure group. Although these findings require more study, said Wang, they may reflect a narrowing in airways caused by early stages of another lung disease, chronic bronchitis.
“To our knowledge, this is the first imaging study to find lung damage in non-smokers heavily exposed to secondhand smoke,” said Wang. “We hope our work strengthens the efforts of legislators and policymakers to limit public exposure to secondhand smoke.”
###
The study received financial support from the National Heart, Lung and Blood Institute, the Flight Attendant Medical Research Institute, the Commonwealth of Virginia Technology Research Fund, and Siemens Medical Solutions.
Wang’s co-authors were Talissa A. Altes, M.D., and Kai Ruppert, Ph.D., now of the Children’s Hospital Radiology Department; and G. Wilson Miller, Ph.D., Eduard E. deLange, M.D., Jaime F. Mata, Ph.D., Gordon D. Cates, Jr., Ph.D., and John P. Mugler III, Ph.D., all of the University of Virginia Department of Radiology. Drs. Wang, Altes, and Ruppert were previously at the University of Virginia as well.
About The Children's Hospital of Philadelphia: The Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals and pioneering major research initiatives, Children's Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country, ranking third in National Institutes of Health funding. In addition, its unique family-centered care and public service programs have brought the 430-bed hospital recognition as a leading advocate for children and adolescents. For more information, visit http://www.chop.edu.
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