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News Article | April 27, 2017
Site: www.prnewswire.com

Cancer develops by stepwise changes in growth characteristics of the cells that may be caused by genetic and epigenetic changes and environmental factors. With the use of new molecular biological methods the analyses of the biological mechanisms behind cancer development have started and generated new important knowledge. Joydeep Bhadury has in this thesis presented important translational cancer research that provides a better understanding of how genetic changes are related to the initiation and development of cancer. "The results of this research can contribute to identify new targets for future effective treatments of various cancer types", says Professor Eva Forssell-Aronsson, executive member of the Assar Gabrielsson Foundation. Assar Gabrielsson was one of the founders of Volvo. In accordance with his wishes, a foundation to provide funding for clinical research into cancer diseases was created in 1962. It primarily supports research projects which are considered to be promising but which do not yet have the necessary weight to attract grants from central funds. The Assar Gabrielsson Award will be presented Thursday May 18 between 12.30 and 14.00 in the Birgit Thilander room at the Academicum at Sahlgrenska Academy, Gothenburg. During the ceremony the award winner will present his research. The ceremony will be held in English. Journalists who would like further information, please contact: Eva Forssell-Aronsson, Professor of Radiation Physics and Executive member of the Assar Gabrielsson Foundation phone: +46-703722626 Urban Wass, Senior Vice president, Research & Innovation policy, Volvo Group and Chair of the Assar Gabrielsson Foundation phone: +46-739028661 For more stories from the Volvo Group, please visit www.volvogroup.com/press. The Volvo Group is one of the world's leading manufacturers of trucks, buses, construction equipment and marine and industrial engines. The Group also provides complete solutions for financing and service. The Volvo Group, which employs about 95,000 people, has production facilities in 18 countries and sells its products in more than 190 markets. In 2016 the Volvo Group's sales amounted to about SEK 302 billion (EUR 31,9 billion). The Volvo Group is a publicly-held company headquartered in Göteborg, Sweden. Volvo shares are listed on Nasdaq Stockholm. For more information, please visit www.volvogroup.com. This information was brought to you by Cision http://news.cision.com http://news.cision.com/volvo/r/assar-gabrielsson-award-for-effective-treatment-of-cancer,c2248561 The following files are available for download: To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/volvo---assar-gabrielsson-award-for-effective-treatment-of-cancer-300447005.html


News Article | May 2, 2017
Site: www.rdmag.com

Crustaceans may hold the key for a new type of wound dressing, preventing thousands of people from developing infections. Researchers have developed a bandage that uses an antibacterial substance formed from chitosan, a fiber taken from crustacean shells. A team from Lodz University of Technology in Poland led by Radoslaw Wach, Ph.D., developed the protective dressing. Hydrogel dressings—which are durable and elastic to easily adapt to the shape of the affected body part—can speed up healing and cool the wound down by providing moisture to the wound. “Since wound healing in severe cases may take a long time—up to several weeks—the probability of bacteria-mediated infection is high,” Wach said in a statement. “Our novel hydrogel dressing could, therefore, prevent many such infections and avoid serious complications.” According to the study, hydrogels are created from two-or multi-component systems of cross-linked polymer chains and water or aqueous medium filling the network voids. Wach was able to adapt the hydrogel dressing manufacturing technique and incorporate an antibacterial and biodegradable substance extracted from the crustacean shells within the dressing itself. According to the study, the essential physical characteristics of the hydrogel remained mostly unchanged, with only a somewhat increased water uptake capacity. This improves functionality of the dressing as extensive exudate for the wound can be efficiently absorbed. The researchers were able to extract the substance by isolating a substance called chitin that is found in the shells and changing its structure by removing most chemical branches from its acetyl groups. This resulted is a purified chitosan that has antimicrobial properties and helps to stop bleeding when added to bandages. They used a technique called irradiation that comprises cross-linking of hydrophilic polymers next to water to form the firm and durable structure of the dressing and sterilize it in a single step. They then used an electron beam to shine the polymer— which contained a solution of chitosan in lactic acid—while making the dressing, allowing the chitosan to become part of the dressing itself. “We developed a composition where chitosan is dissolved in lactic acid and, when added to the regular composition of the dressing, it does not adversely change its ability to cross-link during manufacturing or alter its mechanical and functional properties,” Wach said. “The new hydrogel wound dressing is biologically active.” According to a report by the Review on Antimicrobial Resistance commissioned in 2014 by the U.K., antimicrobial resistance could kill 10 million people each year by 2050. The study was published in Radiation Physics and Chemistry


News Article | May 10, 2017
Site: phys.org

"Historically, radiation has been a blunt tool," said Matt Vaughn, Director of Life Science Computing at the Texas Advanced Computing Center. "However, it's become ever more precise because we understand the physics and biology of systems that we're shooting radiation into, and have improved our ability to target the delivery of that radiation." The science of calculating and assessing the radiation dose received by the human body is known as dosimetry - and here, as in many areas of science, advanced computing plays an important role. Current radiation treatments rely on imaging from computed tomography (CT) scans taken prior to treatment to determine a tumor's location. This works well if the tumor lies in an easily detectable and immobile location, but less so if the area is moving, as in the case of lung cancer. At the University of Texas MD Anderson Cancer Center, scientists are tackling the problem of accurately attacking tumors using a new technology known as an MR-linac that combines magnetic resonance (MR) imaging with linear accelerators (linacs). Developed by Elekta in cooperation with UMC Utrecht and Philips, the MR-linac at MD Anderson is the first of its kind in the U.S. MR-linacs can image a patient's anatomy while the radiation beam is being delivered. This allows doctors to detect and visualize any anatomical changes in a patient during treatment. Unlike CT or other x-ray based imaging modalities, which provide additional ionizing radiation, MRI is harmless to healthy tissue. The MR-linac method offers a potentially significant improvement over current image-guided cancer treatment technology. However, to ensure patients are treated safely, scientists must first correct for the influence of the MRI's magnetic field on the measurements used to calibrate the radiation dose being delivered. Researchers use software called Geant4 to simulate radiation within the detectors. Originally developed by CERN to simulate high energy particle physics experiments, the MD Anderson team has adapted Geant4 to incorporate magnetic fields into their computer dosimetry model. "Since the ultimate aim of the MR-linac is to treat patients, it is important that our simulations be very accurate and that the results be very precise," said Daniel O'Brien, a postdoctoral fellow in radiation physics at MD Anderson. "Geant4 was originally designed to study radiation at much higher energies than what is used to treat patients. We had to perform tests to make sure that we had the accuracy that we needed." Using the Lonestar supercomputer at the Texas Advanced Computing Center (TACC), the research team simulated nearly 17 billion particles of radiation per detector to get the precision that they needed for their study. In August 2016, they published magnetic field correction factors in Medical Physics for six of the most-used ionization chamber detectors (gas-filled chambers that are used to ensure the dose delivered from a therapy unit is correct). They are now working on verifying these results experimentally. "The MR-linac is a very promising technology but it also presents many unique challenges from a dosimetry point of view," O'Brien said. "Over time, our understanding of these effects has improved considerably, but there is still work to be done and resources like TACC are an invaluable asset in making these new technologies safe and reliable." "Our computer simulations are important because their results will serve as the foundation to extend current national and international protocols to perform calibration of conventional linacs to MR-linacs," said Gabriel Sawakuchi, assistant professor of Radiation Physics at MD Anderson. "However, it is important that our results be validated against measurements and independent simulations performed by other groups before used clinically." X-ray radiation is the most frequently used form of high-energy treatment, but a new treatment is emerging that uses a beam of protons to deliver energy directly to the tumor with minimal damage to surrounding tissues and without the side effects of x-ray therapy. Like x-ray radiation, proton therapy blasts tumors with beams of particles. But whereas traditional radiation uses photons, or focused light beams, proton therapy uses ions - hydrogen atoms that have lost an electron. Proton beams have a unique physical characteristic known as the 'Bragg peak' that allows the greatest part of its energy to be transferred to a specific area within the body, where it has maximum destructive effect. X-ray radiation, on the other hand, deposits energy and kills cells along the whole length of the beam. This can lead to unintended cell damage and even secondary cancer that can develop years later. In comparison with current radiation procedures, proton therapy saves healthy tissue in front of and behind the tumor. Since the patient is irradiated from all directions and the intensity of beams can be well modulated, the method provides further reduction of adverse effects. Proton therapy is particularly effective when irradiating tumors near sensitive organs—for instance near the neck, spine, brain or lungs—where stray beams can be particularly damaging. Medical physicists and radiation oncologists from Mayo Clinic in Phoenix, Arizona in collaboration with MD Anderson researchers, recently published a series of papers describing improved planning and use of proton therapy. Writing in Medical Physics in January 2017, they showed that in the three clinical cases included in this study, their chance-constrained model was better at sparing organs at risk than the current method. The model also provided a flexible tool for users to balance between plan robustness and plan quality and was found to be much faster than the commercial solution. The research used the Stampede supercomputer at TACC to conduct computationally intensive studies of the hundreds of factors that go into maximizing the effectiveness of, and minimizing the risk and uncertainties involved in, these treatments. Proton therapy was first developed in the 1950s and came into mainstream in the 1990s. There are currently 12 proton therapy centers nation-wide and the number is growing. However, the cost of the proton beam devices—$200 million dollars, or 30 to 50 times more expensive than a traditional x-ray system—means they are still rare. They are applied only in cases that require extra precision and doctors must maximize their benefit when they are used. Mayo Clinic and MD Anderson operate the most advanced versions of these devices, which perform scanning beam proton therapy and are able to modulate the intensity of the beam. Wei Liu, one of the lead proton therapy researchers at Mayo Clinic, likens the process to 3-D printing, "painting the tumor layer by layer." However, this is accomplished at a distance, through a protocol that must be planned in advance. The specificity of the proton beam, which is its greatest advantage, means that it must be precisely calibrated and that discrepancies from the ideal must be considered. For instance, hospital staff situate patients on the operating surface of the device, and even placing a patient a few millimeters off-center can impact the success of the treatment. Moreover, every patient's body has a slightly different chemical composition, which can make the proton beam stop at a different position from what is intended. Even patients' breathing can throw off the location of the beam placement. "If a patient has a tumor close to the spinal cord and this level of uncertainty exists, then the proton beam can overdose and paralyze the patient," Liu said. The solution to these challenges is robust optimization, which uses mathematical techniques to generate a plan that can manage and mitigate the uncertainties and human errors that may arise. "Each time, we try to mathematically generate a good plan," he said. "There are many unknown variables. You can choose different beam angles or energy or intensity. There are 25,000 variables or more, so generating a plan that is robust to these mistakes and can still get the proper dose distribution to the tumor is a large-scale optimization problem." To solve these problems, Liu and his team use supercomputers at the Texas Advanced Computing Center. "It's very computationally expensive to generate a plan in a reasonable timeframe," he continued. "Without a supercomputer, we can do nothing." Liu has been working on developing the proton beam planning protocols for many years. Leading commercial companies have adopted methods similar to those that Liu and his collaborators developed as the basis for their radiation planning solutions. Recently, Liu and his collaborators extended their studies to include the uncertainties presented by breathing patients, which they call "4D robust optimization," since it takes into account the time component and not just spatial orientation. In the May 2016 issue of the International Journal of Radiation Oncology, they showed that compared to its 3D counterpart, 4D robust optimization for lung cancer treatment provided more robust target dose distribution and better target coverage, while still offering normal tissue protection. "We're trying to provide the patient with the most effective, most reliable, and most efficient proton therapy," Liu said. "Because it's so expensive, we have to do the best job to take advantage of this new technology." Like many forms of cancer therapy, clinicians know that proton therapy works, but precisely how it works is a bit of a mystery. The basic principle is not in question: proton ions collide with water molecules, which make up 70 percent of cells, triggering the release of electrons and free radicals that damage the DNA of cancerous cells. The proton ions also collide with the DNA directly, breaking bonds and crippling DNA's ability to replicate. Because of their high rate of division and reduced ability to repair damaged DNA, cancerous cells are much more vulnerable to DNA attacks than normal cells and are killed at a higher rate. Furthermore, a proton beam can be focused on a tumor area, thus causing maximum damage on cancerous cells and minimum damage on surrounding healthy cells. However, beyond this general microscopic picture, the mechanics of the process have been hard to determine. "As happens in cancer therapy, they know empirically that it works but they don't know why," said Jorge A. Morales, a professor of chemistry at Texas Tech University and a leading proponent of the computational analysis of proton therapy. "To do experiments with human subjects is dangerous, so the best way is through computer simulation." Morales has been running computer simulations of proton-cell chemical reactions using quantum dynamics models on TACC's Stampede supercomputer to investigate the fundamentals of the process. Computational experiments can mimic the dynamics of the proton-cell interactions without causing damage to a patient and can reveal what happens when the proton beam and cells collide from start to finish, with atomic-level accuracy. Quantum simulations are necessary because the electrons and atoms that are the basis for proton cancer therapy's effectiveness do not behave according to the laws of classical physics. Rather they are guided by the laws quantum mechanics which involve probabilities of location, speed and reactions' occurrences rather than to the precisely defined versions of those three variables. Morales' studies on Stampede, reported in PLOS One in March 2017, as well as in Molecular Physics, and Chemical Physics Letters (both 2014), have determined the basic byproducts of protons colliding with water within the cell, and with nucleotides and clusters of DNA bases - the basic units of DNA. The studies shed light on how the protons and their water radiolysis products damage DNA. The results of Morales' computational experiments match the limited data from physical chemistry experiments, leading to greater confidence in their ability to capture the quantum behavior in action. Though fundamental in nature, the insights and data that Morales' simulations produce help researchers understand proton cancer therapy at the microscale, and help modulate factors like dosage and beam direction. "The results are all very promising and we're excited to extend our research further," Morales said. "These simulations will bring about a unique way to understand and control proton cancer therapy that, at a very low cost, will help to drastically improve the treatment of cancer patients without risking human subjects." Explore further: What is cancer radiotherapy, and why do we need proton beam therapy? More information: Austin J. Privett et al, Exploring water radiolysis in proton cancer therapy: Time-dependent, non-adiabatic simulations of H+ + (H2O)1-6, PLOS ONE (2017). DOI: 10.1371/journal.pone.0174456


News Article | May 10, 2017
Site: www.eurekalert.org

Researchers use supercomputers at the Texas Advanced Computing Center to improve, plan, and understand the basic science of, radiation therapy Radiation therapy shoots high-energy particles into the body to destroy or damage cancer cells. Over the last century, the technologies used have constantly improved and it has become a highly effective way to treat cancer. However, physicians must still walk a fine line between delivering enough radiation to kill tumors, while sparing surrounding healthy tissue. "Historically, radiation has been a blunt tool," said Matt Vaughn, Director of Life Science Computing at the Texas Advanced Computing Center. "However, it's become ever more precise because we understand the physics and biology of systems that we're shooting radiation into, and have improved our ability to target the delivery of that radiation." The science of calculating and assessing the radiation dose received by the human body is known as dosimetry - and here, as in many areas of science, advanced computing plays an important role. Current radiation treatments rely on imaging from computed tomography (CT) scans taken prior to treatment to determine a tumor's location. This works well if the tumor lies in an easily detectable and immobile location, but less so if the area is moving, as in the case of lung cancer. At the University of Texas MD Anderson Cancer Center, scientists are tackling the problem of accurately attacking tumors using a new technology known as an MR-linac that combines magnetic resonance (MR) imaging with linear accelerators (linacs). Developed by Elekta in cooperation with UMC Utrecht and Philips, the MR-linac at MD Anderson is the first of its kind in the U.S. MR-linacs can image a patient's anatomy while the radiation beam is being delivered. This allows doctors to detect and visualize any anatomical changes in a patient during treatment. Unlike CT or other x-ray based imaging modalities, which provide additional ionizing radiation, MRI is harmless to healthy tissue. The MR-linac method offers a potentially significant improvement over current image-guided cancer treatment technology. However, to ensure patients are treated safely, scientists must first correct for the influence of the MRI's magnetic field on the measurements used to calibrate the radiation dose being delivered. Researchers use software called Geant4 to simulate radiation within the detectors. Originally developed by CERN to simulate high energy particle physics experiments, the MD Anderson team has adapted Geant4 to incorporate magnetic fields into their computer dosimetry model. "Since the ultimate aim of the MR-linac is to treat patients, it is important that our simulations be very accurate and that the results be very precise," said Daniel O'Brien, a postdoctoral fellow in radiation physics at MD Anderson. "Geant4 was originally designed to study radiation at much higher energies than what is used to treat patients. We had to perform tests to make sure that we had the accuracy that we needed." Using the Lonestar supercomputer at the Texas Advanced Computing Center (TACC), the research team simulated nearly 17 billion particles of radiation per detector to get the precision that they needed for their study. In August 2016, they published magnetic field correction factors in Medical Physics for six of the most-used ionization chamber detectors (gas-filled chambers that are used to ensure the dose delivered from a therapy unit is correct). They are now working on verifying these results experimentally. "The MR-linac is a very promising technology but it also presents many unique challenges from a dosimetry point of view," O'Brien said. "Over time, our understanding of these effects has improved considerably, but there is still work to be done and resources like TACC are an invaluable asset in making these new technologies safe and reliable." "Our computer simulations are important because their results will serve as the foundation to extend current national and international protocols to perform calibration of conventional linacs to MR-linacs," said Gabriel Sawakuchi, assistant professor of Radiation Physics at MD Anderson. "However, it is important that our results be validated against measurements and independent simulations performed by other groups before used clinically." X-ray radiation is the most frequently used form of high-energy treatment, but a new treatment is emerging that uses a beam of protons to deliver energy directly to the tumor with minimal damage to surrounding tissues and without the side effects of x-ray therapy. Like x-ray radiation, proton therapy blasts tumors with beams of particles. But whereas traditional radiation uses photons, or focused light beams, proton therapy uses ions - hydrogen atoms that have lost an electron. Proton beams have a unique physical characteristic known as the 'Bragg peak' that allows the greatest part of its energy to be transferred to a specific area within the body, where it has maximum destructive effect. X-ray radiation, on the other hand, deposits energy and kills cells along the whole length of the beam. This can lead to unintended cell damage and even secondary cancer that can develop years later. In comparison with current radiation procedures, proton therapy saves healthy tissue in front of and behind the tumor. Since the patient is irradiated from all directions and the intensity of beams can be well modulated, the method provides further reduction of adverse effects. Proton therapy is particularly effective when irradiating tumors near sensitive organs -- for instance near the neck, spine, brain or lungs -- where stray beams can be particularly damaging. Medical physicists and radiation oncologists from Mayo Clinic in Phoenix, Arizona in collaboration with MD Anderson researchers, recently published a series of papers describing improved planning and use of proton therapy. Writing in Medical Physics in January 2017, they showed that in the three clinical cases included in this study, their chance-constrained model was better at sparing organs at risk than the current method. The model also provided a flexible tool for users to balance between plan robustness and plan quality and was found to be much faster than the commercial solution. The research used the Stampede supercomputer at TACC to conduct computationally intensive studies of the hundreds of factors that go into maximizing the effectiveness of, and minimizing the risk and uncertainties involved in, these treatments. Proton therapy was first developed in the 1950s and came into mainstream in the 1990s. There are currently 12 proton therapy centers nation-wide and the number is growing. However, the cost of the proton beam devices -- $200 million dollars, or 30 to 50 times more expensive than a traditional x-ray system -- means they are still rare. They are applied only in cases that require extra precision and doctors must maximize their benefit when they are used. Mayo Clinic and MD Anderson operate the most advanced versions of these devices, which perform scanning beam proton therapy and are able to modulate the intensity of the beam. Wei Liu, one of the lead proton therapy researchers at Mayo Clinic, likens the process to 3-D printing, "painting the tumor layer by layer." However, this is accomplished at a distance, through a protocol that must be planned in advance. The specificity of the proton beam, which is its greatest advantage, means that it must be precisely calibrated and that discrepancies from the ideal must be considered. For instance, hospital staff situate patients on the operating surface of the device, and even placing a patient a few millimeters off-center can impact the success of the treatment. Moreover, every patient's body has a slightly different chemical composition, which can make the proton beam stop at a different position from what is intended. Even patients' breathing can throw off the location of the beam placement. "If a patient has a tumor close to the spinal cord and this level of uncertainty exists, then the proton beam can overdose and paralyze the patient," Liu said. The solution to these challenges is robust optimization, which uses mathematical techniques to generate a plan that can manage and mitigate the uncertainties and human errors that may arise. "Each time, we try to mathematically generate a good plan," he said. "There are many unknown variables. You can choose different beam angles or energy or intensity. There are 25,000 variables or more, so generating a plan that is robust to these mistakes and can still get the proper dose distribution to the tumor is a large-scale optimization problem." To solve these problems, Liu and his team use supercomputers at the Texas Advanced Computing Center. "It's very computationally expensive to generate a plan in a reasonable timeframe," he continued. "Without a supercomputer, we can do nothing." Liu has been working on developing the proton beam planning protocols for many years. Leading commercial companies have adopted methods similar to those that Liu and his collaborators developed as the basis for their radiation planning solutions. Recently, Liu and his collaborators extended their studies to include the uncertainties presented by breathing patients, which they call "4D robust optimization," since it takes into account the time component and not just spatial orientation. In the May 2016 issue of the International Journal of Radiation Oncology, they showed that compared to its 3D counterpart, 4D robust optimization for lung cancer treatment provided more robust target dose distribution and better target coverage, while still offering normal tissue protection. "We're trying to provide the patient with the most effective, most reliable, and most efficient proton therapy," Liu said. "Because it's so expensive, we have to do the best job to take advantage of this new technology." Like many forms of cancer therapy, clinicians know that proton therapy works, but precisely how it works is a bit of a mystery. The basic principle is not in question: proton ions collide with water molecules, which make up 70 percent of cells, triggering the release of electrons and free radicals that damage the DNA of cancerous cells. The proton ions also collide with the DNA directly, breaking bonds and crippling DNA's ability to replicate. Because of their high rate of division and reduced ability to repair damaged DNA, cancerous cells are much more vulnerable to DNA attacks than normal cells and are killed at a higher rate. Furthermore, a proton beam can be focused on a tumor area, thus causing maximum damage on cancerous cells and minimum damage on surrounding healthy cells. However, beyond this general microscopic picture, the mechanics of the process have been hard to determine. "As happens in cancer therapy, they know empirically that it works but they don't know why," said Jorge A. Morales, a professor of chemistry at Texas Tech University and a leading proponent of the computational analysis of proton therapy. "To do experiments with human subjects is dangerous, so the best way is through computer simulation." Morales has been running computer simulations of proton-cell chemical reactions using quantum dynamics models on TACC's Stampede supercomputer to investigate the fundamentals of the process. Computational experiments can mimic the dynamics of the proton-cell interactions without causing damage to a patient and can reveal what happens when the proton beam and cells collide from start to finish, with atomic-level accuracy. Quantum simulations are necessary because the electrons and atoms that are the basis for proton cancer therapy's effectiveness do not behave according to the laws of classical physics. Rather they are guided by the laws quantum mechanics which involve probabilities of location, speed and reactions' occurrences rather than to the precisely defined versions of those three variables. Morales' studies on Stampede, reported in PLOS One in March 2017, as well as in Molecular Physics, and Chemical Physics Letters (both 2014), have determined the basic byproducts of protons colliding with water within the cell, and with nucleotides and clusters of DNA bases - the basic units of DNA. The studies shed light on how the protons and their water radiolysis products damage DNA. The results of Morales' computational experiments match the limited data from physical chemistry experiments, leading to greater confidence in their ability to capture the quantum behavior in action. Though fundamental in nature, the insights and data that Morales' simulations produce help researchers understand proton cancer therapy at the microscale, and help modulate factors like dosage and beam direction. "The results are all very promising and we're excited to extend our research further," Morales said. "These simulations will bring about a unique way to understand and control proton cancer therapy that, at a very low cost, will help to drastically improve the treatment of cancer patients without risking human subjects."


News Article | February 22, 2017
Site: phys.org

The metallic chemical elements known as actinides take their name from the first element in the series: actinium. Actinium is one of the heavy, radioactive elements in Mendeleev’s table that are still largely beyond the frontiers of knowledge. Credit: Shutterstock Little is known about the heaviest, radioactive elements in Mendeleev's table. But an extremely sensitive technique involving laser light and gas jets makes it possible for the very first time to gain insight into their atomic and nuclear structure. An international team led by scientists from the Institute for Nuclear and Radiation Physics at KU Leuven report these findings in Nature Communications. In 2016 scientists added four more elements to Mendeleev's periodic table. These heavy elements are not found on Earth and can only be generated using powerful particle accelerators. "The elements are usually generated in minuscule quantities, sometimes just a couple of atoms per year. These atoms are also radioactive, so their decay is quick: sometimes they only exist for a fraction of a second. That is why scientific knowledge of these elements is very limited," say nuclear physicists Mark Huyse and Piet Van Duppen from the KU Leuven Institute for Nuclear and Radiation Physics. The KU Leuven researchers are now hoping to change that through a new use of the laser ionization technique. "We produced actinium (Ac), the name-giving element of the heavy actinides, in a series of experiments using the particle accelerator at Louvain-la-Neuve. The quickly decaying atoms of this element were captured in a gas chamber filled with argon, sucked into a supersonic jet, and spotlighted with laser beams. By doing so we bring the outer electron in a different orbit. A second laser beam then shoots the electron away. This ionizes the atom, meaning that it becomes positively charged and is now easy to manipulate and detect. The colour of the laser light is like a fingerprint of the atomic structure of the element and the structure of its nucleus." In itself, laser ionization is a well-known technique but its use in a supersonic jet is new and very suitable for the heavy, radioactive elements: "By ionizing the atom we significantly increase the sensitivity of the technique. The production of a few atoms per second is already enough for measurements during the experiments. This technology increases the sensitivity, accuracy, and speed of the laser ionization by at least ten times. This marks an entirely new era for research on the heaviest elements and makes it possible to test and correct the theoretical models in nuclear physics. Our method will be used in the new particle accelerator of GANIL, which is currently under construction in France." Explore further: First spectroscopic investigation of element nobelium More information: R. Ferrer et al. Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion, Nature Communications (2017). DOI: 10.1038/NCOMMS14520


News Article | December 20, 2016
Site: www.eurekalert.org

DALLAS - Dec. 20, 2016 - UT Southwestern Medical Center researchers have invented a transistor-like threshold sensor that can illuminate cancer tissue, helping surgeons more accurately distinguish cancerous from normal tissue. In this latest study, researchers were able to demonstrate the ability of the nanosensor to illuminate tumor tissue in multiple mouse models. The study is published in Nature Biomedical Engineering. "We synthesized an imaging probe that stays dark in normal tissues but switches on like a light bulb when it reaches solid tumors. The purpose is to allow surgeons to see tumors better during surgery," said senior author Dr. Jinming Gao, Professor of Oncology, Pharmacology and Otolaryngology with the Harold C. Simmons Comprehensive Cancer Center. The nanosensor amplifies pH signals in tumor cells to more accurately distinguish them from normal cells. "Cancer is a very diverse set of diseases, but it does have some universal features. Tumors do not have the same pH as normal tissue. Tumors are acidic, and they secrete acids into the surrounding tissue. It's a very consistent difference and was discovered in the 1920's," said Dr. Baran Sumer, Associate Professor of Otolaryngology, and co-senior author of the study. The researchers hope the improved surgical technology can eventually benefit cancer patients in multiple ways. "This new digital nanosensor-guided surgery potentially has several advantages for patients, including more accurate removal of tumors, and greater preservation of functional normal tissues," said Dr. Sumer. "These advantages can improve both survival and quality of life." For example, this technology may help cancer patients who face side effects such as incontinence after rectal cancer surgery. "The new technology also can potentially assist radiologists by helping them to reduce false rates in imaging, and assist cancer researchers with non-invasive monitoring of drug responses," said Dr. Gao. According to the National Cancer Institute, there are 15.5 million cancer survivors in the U.S., representing 4.8 percent of the population. The number of cancer survivors is projected to increase by 31 percent, to 20.3 million, by 2026. Dr. Sumer and Dr. Gao were joined in this study by Dr. Gang Huang, Instructor of Pharmacology; Dr. Xian-Jin Xie, Professor of Clinical Sciences; Dr. Rolf Brekken, Professor of Surgery and Pharmacology and an Effie Marie Cain Research Scholar; and Dr. Xiankai Sun, Director of Cyclotron and Radiochemistry Program in Department of Radiology and Advanced Imaging Research Center, Associate Professor of Radiology, and holder of the Dr. Jack Krohmer Professorship in Radiation Physics; Dr. Joel Thibodeaux, Assistant Professor of Pathology and Director of Cytopathology, Parkland Memorial Hospital. Additional UT Southwestern researchers who contributed to the study include: Dr. Tian Zhao, Dr. Xinpeng Ma, Mr. Yang Li, Dr. Zhiqiang Lin, Dr. Min Luo, Dr. Yiguang Wang, Mr. Shunchun Yang and Ms. Zhiqun Zeng in the Harold C. Simmons Comprehensive Cancer Center; and Dr. Saleh Ramezani in the Department of Radiology. Dr. Gao and Dr. Sumer are scientific co-founders of OncoNano Medicine, Inc. The authors declare competing financial interests in the full-text of the Nature Biomedical Engineering article. UT Southwestern Medical Center has licensed the technology to OncoNano Medicine and has a financial interest in the research described in the article. Funding for the project includes grants from the Cancer Prevention and Research Institute of Texas. Dr. Gao and Dr. Sumer are investigators for two Academic Research grants and OncoNano Medicine was the recipient of a CPRIT Product Development Research grant. Research reported in this press release was supported by the National Cancer Institute under Award Number R01 CA192221 and the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The Harold C. Simmons Comprehensive Cancer Center is the only NCI-designated Comprehensive Cancer Center in North Texas and one of just 47 NCI-designated Comprehensive Cancer Centers in the nation. Simmons Cancer Center includes 13 major cancer care programs. In addition, the Center's education and training programs support and develop the next generation of cancer researchers and clinicians. Simmons Cancer Center is among only 30 U.S. cancer research centers to be designated by the NCI as a National Clinical Trials Network Lead Academic Participating Site. UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution's faculty includes many distinguished members, including six who have been awarded Nobel Prizes since 1985. The faculty of almost 2,800 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in about 80 specialties to more than 100,000 hospitalized patients and oversee approximately 2.2 million outpatient visits a year. This news release is available on our website at http://www. . To automatically receive news releases from UT Southwestern via email, subscribe at http://www.


PubMed | Radiosurgery, Institute Of Cancerologie Gustave Roussy, Robotic Radiosurgery Unit, Virgen del Rocio University Hospital and 3 more.
Type: Journal Article | Journal: Cureus | Year: 2016

Modern technologies allow the delivery of high radiation doses to intramedullary spinal cord metastases while lowering the dose to the neighboring organs at risk. Whether this dosimetric advantage translates into clinical benefit is not well known. This study evaluates the acute and late toxicity outcomes in a patient treated with robotic radiosurgery for an intramedullary spinal cord metastasis. A 50-year-old woman diagnosed in May 2006 with invasive ductal carcinoma of the right breast T2N3M1 (two liver metastases) received chemotherapy with a complete response. Subsequently, she underwent adjuvant whole-breast radiotherapy, along with tamoxifen. After several distant relapses, treated mainly with systemic therapy, the patient developed an intramedullary lesion at the C3-C4 level and was referred to our CyberKnife unit for assessment. A total dose of 14 Gy prescribed to the 74% isodose line was administered to the intramedullary lesion in one fraction. One hundred and two treatment beams were used covering 95.63% of the target volume. The mean dose was 15.93 Gy and the maximum dose, 18.92 Gy. Maximum dose to the spinal cord was 13.96 Gy, V12 ~ 0.13 cc and V8 ~ 0.43 cc. Three months after treatment, magnetic resonance imaging showed a reduction in size and enhancement of the intramedullary lesionwith no associated toxicity. During this period, the patient showed a good performance statuswithout neurological deficits. Currently, with a follow-up of 37 months, the patient has the ability to perform activities of daily life. Intramedullary spinal cord metastases is a rare and aggressive disease, often treatment-refractory. Our case demonstrates that radiation therapy delivery with robotic radiosurgery allows the achievement of a high local control without adding toxicity.


News Article | April 8, 2016
Site: www.techtimes.com

Researchers found that new composite metal foams (CMFs) have excellent thermal protection compared to plain metal, turning armor piercing bullet into dust. North Carolina State University researchers studied lightweight CMFs and found that the air pockets inside the metal foams are effective heat blockers. This makes CMFs a promising tool for use in transport and storage of hazardous materials, explosives, nuclear elements, and other heat sensitive materials. It could also prove beneficial for space exploration. Mechanical and aerospace engineering professor at NC State Afsaneh Rabiei shared that this property can be attributed to the hollow spheres in the CMFs, which is composed of stainless steel, carbon steel, or titanium implanted in a metallic matrix of aluminum, metallic alloys, and steel. "The presence of air pockets inside CMF make it so effective at blocking heat, mainly because heat travels more slowly through air than through metal," said Rabiei. The researchers employed two technologies in creating CMFs. One is by making a cast of low melting point matrix material using aluminum to surround the hollow spheres, which has a higher melting point like steel. Another technique is by having prefabricated hollow spheres covered with baked matrix powder, which creates a steel-steel CMF. To prove the heat and fire protection capability of CMFs, the researchers subjected samples of 2.5-inch x 2.5-inch steel-steel CMF that have 0.75 inch thickness to an 800 degree Celsius (1,472 degrees Fahrenheit) fire for 30 minutes. The researchers monitored the material and measured the length of time to reach the other side of the sample. The stainless steel sample only took 4 minutes to breach the 800 degree mark but for the CMF, it took 8 minutes to reach the same temperature. According to Rabiei, CMFs thermal conductivity could prevent accidents from leading to explosions. The research also found that CMFs made up of stainless steel has an 80 percent less expansion at 200 degrees Celsius. The expansion during high heat exposure is constant compared to conventional bulk metals and alloys. Researchers concluded that CMF has excellent thermal insulation, good flame retardant performance, and superior thermal stability when compared to conventional materials available in the market today. In Rabiei's previous study published in the journal Radiation Physics and Chemistry, lightweight metal foams have previously been proven to efficiently block neutron radiation, gamma rays, and X-ray, which can pave the way for more studies that focus on nuclear safety, healthcare applications, and space exploration. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | February 22, 2017
Site: www.eurekalert.org

Little is known about the heaviest, radioactive elements in Mendeleev's table. But an extremely sensitive technique involving laser light and gas jets makes it possible for the very first time to gain insight into their atomic and nuclear structure. An international team led by scientists from the Institute for Nuclear and Radiation Physics at KU Leuven (University of Leuven, Belgium) report these findings in Nature Communications. In 2016 scientists added four more elements to Mendeleev's periodic table. These heavy elements are not found on Earth and can only be generated using powerful particle accelerators. "The elements are usually generated in minuscule quantities, sometimes just a couple of atoms per year. These atoms are also radioactive, so their decay is quick: sometimes they only exist for a fraction of a second. That is why scientific knowledge of these elements is very limited," say nuclear physicists Mark Huyse and Piet Van Duppen from the KU Leuven Institute for Nuclear and Radiation Physics. The KU Leuven researchers are now hoping to change that through a new use of the laser ionization technique. "We produced actinium (Ac), the name-giving element of the heavy actinides, in a series of experiments using the particle accelerator at Louvain-la-Neuve. The quickly decaying atoms of this element were captured in a gas chamber filled with argon, sucked into a supersonic jet, and spotlighted with laser beams. By doing so we bring the outer electron in a different orbit. A second laser beam then shoots the electron away. This ionizes the atom, meaning that it becomes positively charged and is now easy to manipulate and detect. The colour of the laser light is like a fingerprint of the atomic structure of the element and the structure of its nucleus." In itself, laser ionization is a well-known technique but its use in a supersonic jet is new and very suitable for the heavy, radioactive elements: "By ionizing the atom we significantly increase the sensitivity of the technique. The production of a few atoms per second is already enough for measurements during the experiments. This technology increases the sensitivity, accuracy, and speed of the laser ionization by at least ten times. This marks an entirely new era for research on the heaviest elements and makes it possible to test and correct the theoretical models in nuclear physics. Our method will be used in the new particle accelerator of GANIL, which is currently under construction in France." This study is a collaboration between KU Leuven, CRC Louvain-la-Neuve, and research teams from France, Germany, the United Kingdom, and Finland. Additional material, including images, is available on the website of the Institute for Nuclear and Radiation Physics.

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