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  • richardmitnick 8:09 am on July 24, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , ,   

    From physicsworld.com: “Plasmonic chip diagnoses diabetes” 

    physicsworld
    physicsworld.com
    Jul 23, 2014
    Belle Dumé

    A plasmonic chip that can diagnose type-1 diabetes (T1D) has been unveiled by researchers at Stanford University in the US. The chip is capable of detecting diabetes-related biomarkers such as insulin-specific autoantibodies and could be used in hospitals and doctors’ surgeries as a quick and simple way to detect early-stage T1D.

    Diabetes could affect nearly 370 million people worldwide by 2030, according to the World Health Organization. More worrying still, diabetes is now the second most common chronic disease in children. For reasons that are still unclear, the rate of T1D (also known as autoimmune diabetes) in children is increasing by about 3% every year, with a projected increase of a staggering 70% between 2004 and 2020.

    Although T1D was once thought of as being exclusively a childhood disease, around a quarter of individuals now contract it as adults. The rate of type-2 diabetes (T2D) (also called metabolic or diet-induced diabetes), normally seen in overweight adults, has also alarmingly escalated in children since the early 1990s, in part because of the global obesity epidemic. Until quite recently, it was fairly simple to distinguish between T1D and T2D because the diseases had occurred in different groups of people. However, this is becoming more and more difficult because the groups are beginning to overlap. The main problem is that existing diagnostic tests are slow and expensive, and it would be better to detect diabetes as early as possible to ensure the best possible treatment.
    Higher concentration of autoantibodies

    T1D is different from T2D in that patients with the disorder have a much higher concentration of autoantibodies. These are produced by the body and work against one or more pancreatic islet antigens such as insulin, glutamic acid decarboxylase and/or tyrosine phosphatase. Detecting these autoantibodies, and especially those against insulin (which are the first to appear), is therefore a good way to detect T1D. Again, standard tests are not very efficient and even the most widely used technique, radioimmunoassay (RIA) with targeted antigens, is far from ideal because it is slow and relies on toxic radioisotopes.

    In an attempt to overcome these problems, the Stanford researchers have developed an autoantibody test that is more reliable, simple and faster than RIA and similar tests. It comprises a microarray of islet antigens arranged on a plasmonic gold (pGOLD) chip. It can be used to diagnose T1D by detecting the interaction of autoantibodies in a small blood sample with insulin, GAD65 and IA-2, and potentially new biomarkers of the disease. It works with just 2 µL of whole human blood (from a finger-prick sample, for example) and results can be obtained in the same day.

    chip
    Good as gold: detecting diabetes with plasmons

    Enhancing the fluorescence emission

    The team, led by Hongjie Dai, made its pGOLD chip by uniformly coating glass slides with gold nanoparticles that have a surface plasmon resonance in the near-infrared part of the electromagnetic spectrum. Plasmons are collective oscillations of the conduction electrons on the surfaces of the nanoparticles. They allow the nanoparticles to act like tiny antennas, absorbing light at certain resonant frequencies and transferring it efficiently to nearby molecules.

    The result can be a large boost in the fluorescence of the molecule, and the researchers have shown that the pGOLD chip is capable of enhancing the fluorescence emission of near-infrared tags of biological molecules by around 100 times. Together with Brian Feldman’s group, the researchers robotically printed the islet antigens in triplicate spots onto the plasmonic gold slide to create a chip containing a microarray of antigens.

    “We tested our device by applying 2 µL of human serum or blood (diluted by 10 or 100 times) to it,” explains Dai. “If the sample contains autoantibodies that match one or more of the islet antigens on the chip, those antibodies bind to the specific antigens, which are then tagged by a secondary antibody with a near-infrared dye to make the islet spots brightly fluoresce.”
    Antibody detected at much lower concentrations

    The samples came from Feldman’s patients who had new-onset diabetes. They were tested against non-diabetic controls at Stanford University Medical Center.

    The antigen spots fluoresce 100 times more brightly thanks to the plasmonic gold substrate, which allows the antibody to be detected at much lower concentrations (down to just 1 femtomolar) than if ordinary gold were to be employed in the microarray platform.

    “We believe that our technology will be able to address the current clinical need for improved diabetes diagnostics,” Dai says. “The pGOLD platform is also being commercialized by a new start-up company, Nirmidas Biotech, based in San Francisco, aimed at better detecting proteins for a range of research and diagnostic applications. It might even be able to detect biomarkers for other diseases such as heart disease with ultrahigh sensitivity.”

    The researchers describe their plasmonic chip in Nature Medicine.

    This article first appeared on nanotechweb.org

    See the full article here.

    PhysicsWorld is a publication of the Institute of Physics. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

    We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.
    IOP Institute of Physics


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  • richardmitnick 6:57 pm on July 23, 2014 Permalink | Reply
    Tags: Applied Research & Technology, ,   

    From isgtw: “A case for computational mechanics in medicine” 

    international science grid this week

    July 23, 2014
    Monica Kortsha

    Members of the US National Committee on Theoretical and Applied Mechanics and collaborators, including Thomas Hughes, director of the computational mechanics group at the Institute for Computational Engineering and Sciences (ICES) at The University of Texas at Austin, US, and Shaolie Hossain, ICES research fellow and research scientist at the Texas Heart Institute, have published an article reviewing the new opportunities computational mechanics is creating in medicine.

    New treatments for tumor growth and heart disease are just two opportunities presenting themselves. The article is published in the Journal of the Royal Society Interface. “This journal truly serves as an interface between medicine and science,” Hossain says. “If physicians are looking for computational research advancements, the article is sure to grab their attention.”

    The article presents three research areas where computational medicine has already made important progress, and will likely continue to do so: nano and microdevices, biomedical devices — including diagnostic systems, and organ models — and cellular mechanics.

    “[Disease is a] multi-scale phenomena and investigators research diverse aspects of it,” says Hossain, explaining that although disease may be perceived at an organ level, treatments usually function at the molecular and cellular scales.

    Hughes and Hossain’s research on vulnerable plaques (VPs), a category of atherosclerosis responsible for 70% of all lethal heart attacks, is an example of applied research incorporating all three notable areas.

    two
    Hughes and Hossain pictured next to a simulation of a vulnerable plaque within an artery. Current medical techniques cannot effectively detect vulnerable plaques. However, Hughes and Hossain say that nano-particles and computational modeling technologies offer diagnostic and treatment solutions. Image courtesy the Institute for Computational Engineering and Sciences at The University of Texas at Austin, US.

    “The detection and treatment of VPs represents an enormous unmet clinical need,” says Hughes. “Progress on this has the potential to save innumerable lives. Computational mechanics combined with high-performance computing provides new and unique technologies for investigating disease, unlike anything that has been traditionally used in medical research.”

    heart
    HeartFlow uses anatomic data from coronary artery CT scans to create a 3D model of the coronary arteries. Coronary blood flow and pressure are computed by applying the principles of coronary physiology and computational fluid dynamics. Fractional flow reserve (FFRCT) is calculated as the ratio of distal coronary pressure to proximal aortic pressure, under conditions simulating maximal coronary hyperemia. The image demonstrates a stenosis (narrowing) of the left anterior descending coronary artery with an FFRCT of 0.58 distal to the stenosis (in red). FFR values ≤0.80 are hemodynamically significant (meaning they obstruct blood flow) and indicate that the patient may benefit from coronary revascularization (removing or bypassing blockages). Image courtesy HeartFlow.

    The high mortality rate attributed to VPs stems from their near clinical invisibility; conventional plaque detection techniques such as MRI and CT scanning do not register VPs because significant vascular narrowing is not present. Hughes and Hossain, however, have developed a computational toolset that can aid in making the plaques visible through targeted delivery of functionalized nanoparticles.

    Their computational models draw on patient-specific data to predict how well nanoparticles can adhere to a potential plaque, thus enabling researchers to test and refine site-specific treatments. If a VP is detected, the same techniques can be employed to send nanoparticles containing medicine directly to the VP.

    The models are being applied at the Texas Heart Institute, where Hossain is a research scientist and assistant professor. “Early intervention and prevention of heart attacks are where we certainly want to go and we are excited about the possibilities for computational mechanics being a vehicle to get us there safely and more rapidly,” says James Willerson, Texas Heart Institute president.

    Other computationally aided models are already being used to help physicians evaluate and treat patients. HeartFlow, a company founded by Charles Taylor, uses CT scan data to create patient-specific models of arteries, which can be used to diagnose coronary artery disease.

    Despite its success and demonstrated potential, computational mechanics in the medical field is still a new concept for scientists and physicians alike, says Hossain. “The potential that we have, in my opinion, hasn’t been tapped to the fullest because of the gap in knowledge.”

    To help integrate medicine into a field that has historically focused on more traditional engineering domains, the article advocates for incorporating biology and chemistry questions into computational mechanics classes, as well as offering classes that can benefit both medical and computational science students.

    See the full article here.

    iSGTW is an international weekly online publication that covers distributed computing and the research it enables.

    “We report on all aspects of distributed computing technology, such as grids and clouds. We also regularly feature articles on distributed computing-enabled research in a large variety of disciplines, including physics, biology, sociology, earth sciences, archaeology, medicine, disaster management, crime, and art. (Note that we do not cover stories that are purely about commercial technology.)

    In its current incarnation, iSGTW is also an online destination where you can host a profile and blog, and find and disseminate announcements and information about events, deadlines, and jobs. In the near future it will also be a place where you can network with colleagues.

    You can read iSGTW via our homepage, RSS, or email. For the complete iSGTW experience, sign up for an account or log in with OpenID and manage your email subscription from your account preferences. If you do not wish to access the website’s features, you can just subscribe to the weekly email.”


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  • richardmitnick 10:29 am on July 23, 2014 Permalink | Reply
    Tags: , Applied Research & Technology, , , , TITAN Supercomputer   

    From DOE Pulse: “Ames Lab scientist hopes to improve rare earth purification process” 

    pulse

    July 21, 2014
    Austin Kreber, 515.987.4885,
    ajkreber@iastate.edu

    Using the second fastest supercomputer in the world, a scientist at the U.S. Department of Energy’s Ames Laboratory is attempting to develop a more efficient process for purifying rare-earth materials.

    Dr. Nuwan De Silva, a postdoctoral research associate at the Ames Laboratory’s Critical Materials Institute, said CMI scientists are honing in on specific types of ligands they believe will only bind with rare-earth metals. By binding to these rare metals, they believe they will be able to extract just the rare-earth metals without them being contaminated with other metals.

    nd
    Nuwan De Silva, scientist at the Ames
    Laboratory, is developing software to help improve purification of rare-earth materials. Photo credit: Sarom Leang

    Rare-earth metals are used in cars, phones, wind turbines, and other devices important to society. De Silva said China now produces 80-90 percent of the world’s supply of rare-metals and has imposed export restrictions on them. Because of these new export limitations, many labs, including the CMI, have begun trying to find alternative ways to obtain more rare-earth metals.

    Rare-earth metals are obtained by extracting them from their ore. The current extraction process is not very efficient, and normally the rare-earth metals produced are contaminated with other metals. In addition the rare-earth elements for various applications need to be separated from each other, which is a difficult process, one that is accomplished through a solvent extraction process using an aqueous acid solution.

    CMI scientists are focusing on certain types of ligands they believe will bind with just rare-earth metals. They will insert a ligand into the acid solution, and it will go right to the metal and bind to it. They can then extract the rare-earth metal with the ligand still bound to it and then remove the ligand in a subsequent step. The result is a rare-earth metal with little or no contaminants from non rare-earth metals. However, because the solution will still contain neighboring rare-earth metals, the process needs to be repeated many times to separate the other rare earths from the desired rare-earth element.

    The ligand is much like someone being sent to an airport to pick someone up. With no information other than a first name — “John” — finding the right person is a long and tedious process. But armed with a description of John’s appearance, height, weight, and what he is doing, finding him would be much easier. For De Silva, John is a rare-earth metal, and the challenge is developing a ligand best adapted to finding and binding to it.

    To find the optimum ligand, De Silva will use Titan to search through all the possible candidates. First, Titan has to discover the properties of a ligand class. To do that, it uses quantum-mechanical (QM) calculations. These QM calculations take around a year to finish.

    ORNL Titan Supercomputer
    TITAN at ORNL

    Once the QM calculations are finished, Titan uses a program to examine all the parameters of a particular ligand to find the best ligand candidate. These calculations are called molecular mechanics (MM). MM calculations take about another year to accomplish their task.

    “I have over 2,500,000 computer hours on Titan available to me so I will be working with it a lot,” De Silva said. “I think the short term goal of finding one ligand that works will take two years.”

    The CMI isn’t the only lab working on this problem. The Institute is partnering with Oak Ridge National Laboratory, Lawrence Livermore National Laboratory and Idaho National Laboratory as well as numerous other partners. “We are all in constant communication with each other,” De Silva said.

    See the full article here.

    DOE Pulse highlights work being done at the Department of Energy’s national laboratories. DOE’s laboratories house world-class facilities where more than 30,000 scientists and engineers perform cutting-edge research spanning DOE’s science, energy, National security and environmental quality missions. DOE Pulse is distributed twice each month.

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  • richardmitnick 8:21 pm on July 22, 2014 Permalink | Reply
    Tags: Applied Research & Technology, Imaging, , ,   

    From physicsworld.com: “New medical probe combines sound and electromagnetic induction” 

    physicsworld
    physicsworld.com

    Jul 22, 2014
    Tim Wogan

    The Lorentz force combined with acoustic shear waves could help doctors detect dangerous diseases, say researchers in France. The team has shown that the electromagnetic force could create oscillations in living tissue, producing shear waves that can be detected to reveal the tissue’s elasticity. The technique has shown promise in the laboratory and could now be developed as a clinical technique.

    shear
    shear wave

    An experienced doctor can determine a lot about the human body by simply pressing on it with their fingers, a process called palpation. Many serious medical conditions such as breast cancer can be diagnosed this way because they cause tissue to be firmer than normal. Some internal organ diseases such as liver fibrosis also cause the tissue to stiffen, but, in general, these organs are inaccessible to manual palpation. While the texture of internal tissue can be probed by medical imaging techniques such as ultrasound, these techniques measure a different quantity from palpation.

    Shear propagation

    When tissue oscillates, it supports both pressure wave (back-and-forth motion) and shear waves (side-to-side movement). Traditional ultrasound techniques operate in the megahertz range and at these frequencies shear waves propagate just a few microns in tissue. As a result, most ultrasound techniques rely on using pressure waves to determine the compression modulus of the tissue.

    sw
    Shear waves propagating through a tissue dummy

    However, tissue is mainly water – an incompressible fluid – so its firmness to the touch depends on how easily it moves aside to allow a doctor’s fingers to sink in. This is defined by the shear modulus, which can be calculated from the speed of the shear waves in the tissue. Therefore, measuring the sheer modulus can give doctors a map of the inside of the human body as if they could “touch organs and evaluate their stiffness”, says team member Stephan Catheline of the University of Lyon.
    Frequency drop

    In the past few years, researchers have developed ways of measuring the shear modulus by using shear waves with a much lower frequency, which propagate further in soft tissue. These waves are created inside the body by firing focused ultrasound through the skin, but this has its drawbacks. The brain, for example, is protected against shock and vibration by both the skull and the thin layer of cerebrospinal fluid lining it, which makes inducing shear waves difficult.

    Now Catheline and colleagues have adapted an idea called magneto-acoustical electrical tomography to create the shear waves. This involves passing an alternating electric current through tissue in an applied magnetic field. The resulting electromagnetic Lorentz force induces shear-wave oscillations in the tissue. While other researchers had used a high-frequency alternating current, the team used a frequency of only 10–1000 Hz. Using a synthetic tissue substitute called a phantom, and then a sample of pig liver, the researchers tested out their idea, showing that they could induce low-frequency waves with an electric current and detect them using ultrasound transducers. Their results for the pig liver agreed with accepted values for the shear elasticity of healthy liver tissue.
    High electric fields

    Before the research can be used in medicine, there are some difficulties to address. First, the researchers needed high electric fields to generate a large enough Lorentz force. They estimate that the electrical current passing through the tissue was 100 times higher than accepted safety limits, albeit only momentarily. However, modern magnetic resonance imaging (MRI) scanners can generate magnetic fields many times higher than the 100 mT available from the permanent magnets in the team’s laboratory: using these, one could generate the same Lorentz force with a lower electric field. Second, the cerebrospinal fluid that prevents ultrasound from getting into the brain would also stop it getting out, so one would need another way to detect cerebral shear waves. Here too, MRI might provide the answer, as it has been used in the clinic to detect tissue oscillations.

    Kathy Nightingale, an elastography expert at Duke University in North Carolina, says that “so far, what’s exciting about this research is that it’s the first demonstration that I’m aware of of the generation of shear waves using this Lorentz force approach”. There are clear challenges in liver elastography, her own specialism, on patients with livers further below the skin, such as obese patients, she explains. “If this were to be successful in that population, that could be significant,” she says, but stresses that we will have to “wait and see”.

    The research will be published in Physical Review Letters.

    See the full article here.

    PhysicsWorld is a publication of the Institute of Physics. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

    We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.
    IOP Institute of Physics


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  • richardmitnick 7:36 pm on July 22, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , , , ,   

    From SLAC: “Bringing High-energy X-rays into Better Focus” 


    SLAC Lab

    July 22, 2014
    SLAC-invented Etching Process Builds Custom Nanostructures for X-ray Optics

    Scientists at the Department of Energy’s SLAC National Accelerator Laboratory have invented a customizable chemical etching process that can be used to manufacture high-performance focusing devices for the brightest X-ray sources on the planet, as well as to make other nanoscale structures such as biosensors and battery electrodes.

    “The tools researchers use to manipulate X-rays today are very limited,” said Anne Sakdinawat, an associate staff scientist at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) who developed the new “V-MACE” process with Chieh Chang, an SSRL research associate.

    scan
    Scanning electron microscope image of a cleaved spiral zone plate, a type of X-ray optic, created using a chemical etching technique that was developed at SLAC. (Chieh Chang, Anne Sakdinawat)

    “Our new technique for fabricating high performance X-ray optics involves just a few chemicals in a simple, easy-to-implement, one-step technology,” Sakdinawat said. “It offers significant advantages in many far-ranging applications.” The patent-pending technique is detailed in the June 27 edition of Nature Communications.

    Focusing X-rays, particularly higher-energy or “hard” X-rays, is particularly challenging at the nanoscale, though it is key to the success of many scientific studies at two of SLAC’s DOE Office of Science user facilities, SSRL and the Linac Coherent Light Source (LCLS) X-ray laser.

    It is also of great interest for commercial applications such as X-ray microscopy, complex electronics, and biomedical devices and imaging tools.

    Existing tools for focusing hard X-rays, such as specialized mirrors and sequences of concave metal structures that form lenses, are generally limited in how they can shape the X-ray light. Focusing the highest-energy X-rays to produce crisp images remains a challenge, as the focusing tools themselves generally lack nanoscale precision and sap away much of the X-ray energy.

    “It’s been technologically very difficult to fabricate structures that offer both high resolution and high efficiency,” Sakdinawat said, and the effectiveness of the structures, which are examples of X-ray “diffractive optics,” is typically based on the height and precision of their features.

    The new fabrication technique is adapted from a process used to create hairlike silicon wires for research on advanced batteries and electronics. It can fabricate structures up to 100 times as tall as they are wide, with dimensions accurate to billionths of a meter. The technique reduces the need to stack multiple layers to create tall structures.

    The researchers used the etching technique to build tall, precise X-ray diffractive optics, called zone plates, whose thinly spaced lines, symmetric rings or spiral patterns alternately obstruct or phase-shift X-rays and allow them to pass through in a way that separates and refocuses them. This improves the focus and produces higher-quality images.

    zone
    Scanning electron microscope (SEM) image of a zone plate pattern produced using a chemical etching technique invented at SLAC. (Chieh Chang, Anne Sakdinawat)

    zone2
    This scanning electron microscope image shows a cross-sectional view of a zone plate produced using a patent-pending chemical etching technique called “V-MACE” developed at SLAC. (Chieh Chang, Anne Sakdinawat)

    “Basically, this is like an artificial crystal,” Sakdinawat said, diffracting the X-ray light in a predictable pattern, as a crystal would. “You can basically manipulate the light in whatever fashion you want – you can shape the light in different ways,” she said, based on the design of the optics and the needs of the experiment.

    Sakdinawat and Chang tested and imaged a sample zone plate at SSRL, and they hope to construct similar plates for use in experiments at SSRL and LCLS.

    The same technique can be used to build other types of precise silicon and metal-coated nanostructures, such as filtration devices, thermoelectric devices that can create electricity from heat and components for tiny bio-sensors that can be embedded in the body, and researchers are working to tailor the process to suit the needs of government agencies and corporate partners.

    “We’re trying to expand into other fields,” Sakdinawat said. “There are many different applications for this.”

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
    i1


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  • richardmitnick 10:16 pm on July 21, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , , , , ,   

    From WCG: “Pioneering a Molecular Approach to Fighting AIDS” 

    World Community Grid

    Dr. Arthur Olson
    Professor, The Scripps Research Institute
    21 Jul 2014

    Summary
    World Community Grid is being featured at the 20th International AIDS Conference which begins today in Melbourne, Australia. Dr. Arthur Olson, FightAIDS@Home principal investigator, shares his perspective on how World Community Grid is helping his team develop therapies and a potential cure for AIDS.

    The Scripps Research Institute’s FightAIDS@Home initiative is a large-scale computational research project whose goal is to use our knowledge of the molecular biology of the AIDS virus HIV to help defeat the AIDS epidemic. We rely on World Community Grid to provide massive computational power donated by people around the world to speed our research. The “virtual supercomputer” of World Community Grid enables us to model the known atomic structures of HIV molecules to help us design new drugs that could disrupt the function of these molecules. World Community Grid is an essential tool in our quest to understand and subvert the HIV virus’s ability to infect, spread and develop resistance to drug therapies.

    FightAidsOlsonLab@home

    Since the early 1980s – when AIDS was first recognized as a new epidemic and a serious threat to human health – our ability to combat the HIV virus has evolved. Using what we call “structure-based drug discovery,” researchers have been able to use information about HIV’s molecular component to design drugs to defeat it. Critical to this process has been our ability to develop and deploy advanced computational models to help us predict how certain chemical compounds could affect the HIV virus. The development of our AutoDock modelling application – combined with the computational power of World Community Grid – represents a significant breakthrough in our ability to fight HIV.

    By the mid 1990s, the first structure-based HIV protease inhibitors were approved for the treatment of AIDS. These inhibitors enabled the development of highly active antiretroviral therapy (HAART), which in turn resulted in a rapid decline of AIDS deaths where such treatment was available. In the intervening years, thanks in part to the U.S. National Institute of General Medical Sciences AIDS-related Structural Biology Program, we have learned a lot about the molecular structure of HIV. But the more we understand the structure of the virus, the more complex our computational models need to be to unlock the secrets of HIV.

    World Community Grid has enabled our research to progress well beyond what we could have dreamed of when we started our HIV research in the early 1990s. Through our FightAIDS@Home project, we can screen millions of chemical compounds to evaluate their effectiveness against HIV target proteins – including those known to be drug-resistant. By deploying these and other methods, we have significantly increased our understanding of HIV and its ability to evolve to resist treatment. Using these computational capabilities, we have just begun working with an HIV Cure researcher to help us move beyond treatment in search of a cure.

    See the full article here.

    World Community Grid (WCG) brings people together from across the globe to create the largest non-profit computing grid benefiting humanity. It does this by pooling surplus computer processing power. We believe that innovation combined with visionary scientific research and large-scale volunteerism can help make the planet smarter. Our success depends on like-minded individuals – like you.”

    WCG projects run on BOINC software from UC Berkeley.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing.

    CAN ONE PERSON MAKE A DIFFERENCE? YOU BETCHA!!

    “Download and install secure, free software that captures your computer’s spare power when it is on, but idle. You will then be a World Community Grid volunteer. It’s that simple!” You can download the software at either WCG or BOINC.

    Please visit the project pages-

    Say No to Schistosoma

    GO Fight Against Malaria

    Drug Search for Leishmaniasis

    Computing for Clean Water

    The Clean Energy Project

    Discovering Dengue Drugs – Together

    Help Cure Muscular Dystrophy

    Help Fight Childhood Cancer

    Help Conquer Cancer

    Human Proteome Folding

    FightAIDS@Home

    Computing for Sustainable Water

    Mapping Cancer Markers
    Mapping Cancer Markers Banner

    World Community Grid is a social initiative of IBM Corporation
    IBM Corporation
    ibm

    IBM – Smarter Planet
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  • richardmitnick 3:24 pm on July 21, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , , ,   

    From DOE Pulse: “Diamond plates create nanostructures through pressure, not chemistry “ 

    pulse

    July 21, 2014
    Darrick Hurst, 505.844.8009,
    drhurst@sandia.gov

    You wouldn’t think that mechanical force — the simple kind used to eject unruly patrons from bars, shoe a horse or emboss the raised numerals on credit cards — could process nanoparticles more subtly than the most advanced chemistry.

    Yet, in a recent paper in Nature Communications, Sandia National Laboratories researcher Hongyou Fan and colleagues appear to have achieved a start toward that end.

    three
    Sandia National Laboratories researcher Hongyou Fan, center, points out a nanoscience result to Sandia paper co-authors Paul Clem, left, and Binsong Li.
    (Photo by Randy Montoya)

    Their newly patented and original method uses simple pressure — a kind of high-tech embossing — to produce finer and cleaner results in forming silver nanostructures than do chemical methods, which are not only inflexible in their results but leave harmful byproducts to dispose of.

    Fan calls his approach “a simple stress-based fabrication method” that, when applied to nanoparticle arrays, forms new nanostructures with tunable properties.

    “There is a great potential market for this technology,” he said. “It can be readily and directly integrated into current industrial manufacturing lines without creating new expensive and specialized equipment.”

    Said Sandia co-author Paul Clem, “This is a foundational method that should enable a variety of devices, including flexible electronics such as antennas, chemical sensors and strain detectors.” It also would produce transparent electrodes for solar cells and organic light-emitting diodes, Clem said.

    The method was inspired by industrial embossing processes in which a patterned mask is applied with high external pressure to create patterns in the substrate, Fan said. “In our technology, two diamond anvils were used to sandwich nanoparticulate thin films. This external stress manually induced transitions in the film that synthesized new materials,” he said.

    The pressure, delivered by two diamond plates tightened by four screws to any controlled setting, shepherds silver nanospheres into any desired volume. Propinquity creates conditions that produce nanorods, nanowires and nanosheets at chosen thicknesses and lengths rather than the one-size-fits-all output of a chemical process, with no environmentally harmful residues.

    While experiments reported in the paper were performed with silver — the most desirable metal because it is the most conductive, stable and optically interesting and becomes transparent at certain pressures — the method also has been shown to work with gold, platinum and other metallic nanoparticles

    Clem said the researchers are now starting to work with semiconductors.

    Bill Hammetter, manager of Sandia’s Advanced Materials Laboratory, said, “Hongyou has discovered a way to build one structure into another structure — a capability we don’t have now at the nanolevel. Eight or nine gigapascal —the amount of pressure at which phase change and new materials occur — are not difficult to reach. Any industry that has embossing equipment could lay a film of silver on a piece of paper, build a conductive pattern, then remove the extraneous material and be left with the pattern. A coating of nanoparticles that can build into another structure has a certain functionality we don’t have right now. It’s a discovery that hasn’t been commercialized, but could be done today with the same equipment used by anyone who makes credit cards.”

    The method can be used to configure new types of materials. For example, under pressure, the dimensions of ordered three-dimensional nanoparticle arrays shrink. By fabricating a structure in which the sandwiching walls permanently provide that pressure, the nanoparticle array will remain at a constant state, able to transmit light and electricity with specific characteristics. This pressure-regulated fine-tuning of particle separation enables controlled investigation of distance-dependent optical and electrical phenomena.

    At even higher pressures, nanoparticles are forced to sinter, or bond, forming new classes of chemically and mechanically stable nanostructures that no longer need restraining surfaces. These cannot be manufactured using current chemical methods.

    Depending on the size, composition and phase orientation of the initial nanoparticle arrays, a variety of nanostructures or nanocomposites and 3-D interconnected networks are achievable.

    The stress-induced synthesis processes are simple and clean. No thermal processing or further purification is needed to remove reaction byproducts.
    This work was funded by the Department of Energy’s Office of Science. Other authors of the paper are from Cornell University and Los Alamos National Laboratory.

    See the full article here.

    DOE Pulse highlights work being done at the Department of Energy’s national laboratories. DOE’s laboratories house world-class facilities where more than 30,000 scientists and engineers perform cutting-edge research spanning DOE’s science, energy, National security and environmental quality missions. DOE Pulse is distributed twice each month.

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  • richardmitnick 9:17 am on July 21, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , ,   

    From Fermilab: “Prototype CT scanner could improve targeting accuracy in proton therapy treatment” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Monday, July 21, 2014
    Rhianna Wisniewski

    A prototype proton CT scanner developed by Fermilab and Northern Illinois University could someday reduce the amount of radiation delivered to healthy tissue in a patient undergoing cancer treatment.

    ct
    Members of the prototype proton CT scanner collaboration move the detector into the CDH Proton Center in Warrenville. Photo: Reidar Hahn

    The proton CT scanner would better target radiation doses to the cancerous tumors during proton therapy treatment. Physicists recently started testing with beam at the CDH Proton Center in Warrenville.

    To create a custom treatment plan for each proton therapy patient, radiation oncologists currently use X-ray CT scanners to develop 3-D images of patient anatomy, including the tumor, to determine the size, shape and density of all organs and tissues in the body. To make sure all the tumor cells are irradiated to the prescribed dose, doctors often set the targeting volume to include a minimal amount of healthy tissue just outside the tumor.

    Collaborators believe that the prototype proton CT, which is essentially a particle detector, will provide a more precise 3-D map of the patient anatomy. This allows doctors to more precisely target beam delivery, reducing the amount of radiation to healthy tissue during the CT process and treatment.

    “The dose to the patient with this method would be lower than using X-ray CTs while getting better precision on the imaging,” said Fermilab’s Peter Wilson, PPD associate head for engineering and support.

    Fermilab became involved in the project in 2011 at the request of NIU’s high-energy physics team because of the laboratory’s detector building expertise.

    The project’s goal was a tall order, Wilson explained. The group wanted to build a prototype device, imaging software and computing system that could collect data from 1 billion protons in less than 10 minutes and then produce a 3-D reconstructed image of a human head, also in less than 10 minutes. To do that, they needed to create a device that could read data very quickly, since every second data from 2 million protons would be sent from the device — which detects only one proton at a time — to a computer.

    NIU physicist Victor Rykalin recommended building a scintillating fiber tracker detector with silicon photomultipliers. A similar detector was used in the DZero experiment.

    “The new prototype CT is a good example of the technical expertise of our staff in detector technology. Their expertise goes back 35 to 45 years and is really what makes it possible for us to do this,” Wilson said.

    In the prototype CT, protons pass through two tracking stations, which track the particles’ trajectories in three dimensions. (See figure below.) The protons then pass through the patient and finally through two more tracking stations before stopping in the energy detector, which is used to calculate the total energy loss through the patient. Devices called silicon photomultipliers pick up signals from the light resulting from these interactions and subsequently transmit electronic signals to a data acquisition system.

    scheme
    In the prototype proton CT scanner, protons enter from the left, passing through planes of fibers and the patient’s head. Data from the protons’ trajectories, including the energy deposited in the patient, is collected in a data acquisition system (right), which is then used to map the patient’s tissue. Image courtesy of George Coutrakon, NIU

    Scientists use specialized software and a high-performance computer at NIU to accurately map the proton stopping powers in each cubic millimeter of the patient. From this map, visually displayed as conventional CT slices, the physician can outline the margins, dimensions and location of the tumor.

    Elements of the prototype were developed at both NIU and Fermilab and then put together at Fermilab. NIU developed the software and computing systems. The teams at Fermilab worked on the design and construction of the tracker and the electronics to read the tracker and energy measurement. The scintillator plates, fibers and trackers were also prepared at Fermilab. A group of about eight NIU students, led by NIU’s Vishnu Zutshi, helped build the detector at Fermilab.

    “A project like this requires collaboration across multiple areas of expertise,” said George Coutrakon, medical physicist and co-investigator for the project at NIU. “We’ve built on others’ previous work, and in that sense, the collaboration extends beyond NIU and Fermilab.”

    See the full article here.

    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.


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  • richardmitnick 9:08 am on July 21, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , , , ,   

    From M.I.T.: “More than glitter” 


    M.I.T.

    July 21, 2014
    Anne Trafton | MIT News Office

    Scientists explain how gold nanoparticles easily penetrate cells, making them useful for delivering drugs.

    A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells.

    A new study from MIT materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons. In the July 21 issue of Nature Communications, the researchers describe in detail the mechanism by which these nanoparticles are able to fuse with a membrane.

    cell
    MIT engineers created simulations of how a gold nanoparticle coated with special molecules can penetrate a membrane. At left, the particle (top) makes contact with the membrane. At right, it has fused to the membrane. Image: Reid Van Lehn

    The findings suggest possible strategies for designing nanoparticles — made from gold or other materials — that could get into cells even more easily.

    “We’ve identified a type of mechanism that might be more prevalent than is currently known,” says Reid Van Lehn, an MIT graduate student in materials science and engineering and one of the paper’s lead authors. “By identifying this pathway for the first time it also suggests not only how to engineer this particular class of nanoparticles, but that this pathway might be active in other systems as well.”

    The paper’s other lead author is Maria Ricci of École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. The research team, led by Alfredo Alexander-Katz, an associate professor of materials science and engineering, and Francesco Stellacci from EPFL, also included scientists from the Carlos Besta Institute of Neurology in Italy and Durham University in the United Kingdom.

    Most nanoparticles enter cells through endocytosis, a process that traps the particles in intracellular compartments, which can damage the cell membrane and cause cell contents to leak out. However, in 2008, Stellacci, who was then at MIT, and Darrell Irvine, a professor of materials science and engineering and of biological engineering, found that a special class of gold nanoparticles coated with a mix of molecules could enter cells without any disruption.

    “Why this was happening, or how this was happening, was a complete mystery,” Van Lehn says.

    Last year, Alexander-Katz, Van Lehn, Stellacci, and others discovered that the particles were somehow fusing with cell membranes and being absorbed into the cells. In their new study, they created detailed atomistic simulations to model how this happens, and performed experiments that confirmed the model’s predictions.

    Stealth entry

    Gold nanoparticles used for drug delivery are usually coated with a thin layer of molecules that help tune their chemical properties. Some of these molecules, or ligands, are negatively charged and hydrophilic, while the rest are hydrophobic. The researchers found that the particles’ ability to enter cells depends on interactions between hydrophobic ligands and lipids found in the cell membrane.

    Cell membranes consist of a double layer of phospholipid molecules, which have hydrophobic lipid tails and hydrophilic heads. The lipid tails face in toward each other, while the hydrophilic heads face out.

    In their computer simulations, the researchers first created what they call a “perfect bilayer,” in which all of the lipid tails stay in place within the membrane. Under these conditions, the researchers found that the gold nanoparticles could not fuse with the cell membrane.

    However, if the model membrane includes a “defect” — an opening through which lipid tails can slip out — nanoparticles begin to enter the membrane. When these lipid protrusions occur, the lipids and particles cling to each other because they are both hydrophobic, and the particles are engulfed by the membrane without damaging it.

    In real cell membranes, these protrusions occur randomly, especially near sites where proteins are embedded in the membrane. They also occur more often in curved sections of membrane, because it’s harder for the hydrophilic heads to fully cover a curved area than a flat one, leaving gaps for the lipid tails to protrude.

    “It’s a packing problem,” Alexander-Katz says. “There’s open space where tails can come out, and there will be water contact. It just makes it 100 times more probable to have one of these protrusions come out in highly curved regions of the membrane.”

    Mimicking nature

    This phenomenon appears to mimic a process that occurs naturally in cells — the fusion of vesicles with the cell membrane. Vesicles are small spheres of membrane-like material that carry cargo such as neurotransmitters or hormones.

    The similarity between absorption of vesicles and nanoparticle entry suggests that cells where a lot of vesicle fusion naturally occurs could be good targets for drug delivery by gold nanoparticles. The researchers plan to further analyze how the composition of the membranes and the proteins embedded in them influence the absorption process in different cell types. “We want to really understand all the constraints and determine how we can best design nanoparticles to target particular cell types, or regions of a cell,” Van Lehn says.

    “One could use the results from this paper to think about how to leverage these findings into improved nanoparticle delivery vehicles — for instance, perhaps new surface ligands for nanoparticles could be engineered to have improved affinity for both surface groups and lipid tails,” says Catherine Murphy, a professor of chemistry at the University of Illinois at Urbana-Champaign who was not involved in the study.

    The research was funded by the National Science Foundation and the Swiss National Foundation.

    See the full article, with video, here.


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  • richardmitnick 8:51 am on July 21, 2014 Permalink | Reply
    Tags: Applied Research & Technology, , , , , Solar Energy   

    From M.I.T.: “Steam from the sun” 


    M.I.T.

    July 21, 2014
    Jennifer Chu | MIT News Office

    New spongelike structure converts solar energy into steam.

    A new material structure developed at MIT generates steam by soaking up the sun.

    beaker

    On the left, a representative structure for localization of heat; the cross section of structure and temperature distribution. On the right, a picture of enhanced steam generation by the DLS structure under solar illumination. Courtesy of the researchers

    sponge
    The DLS that consists of a carbon foam (10-mm thick) supporting an exfoliated graphite layer (B5-mm thick). Both layers are hydrophilic to promote the capillary rise of water to the surface. Courtesy of the researchers

    The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.

    The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation. What’s more, the setup loses very little heat in the process, and can produce steam at relatively low solar intensity. This would mean that, if scaled up, the setup would likely not require complex, costly systems to highly concentrate sunlight.

    Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, says the spongelike structure can be made from relatively inexpensive materials — a particular advantage for a variety of compact, steam-powered applications.

    “Steam is important for desalination, hygiene systems, and sterilization,” says Ghasemi, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”

    Ghasemi and mechanical engineering department head Gang Chen, along with five others at MIT, report on the details of the new steam-generating structure in the journal Nature Communications.

    Cutting the optical concentration

    Today, solar-powered steam generation involves vast fields of mirrors or lenses that concentrate incoming sunlight, heating large volumes of liquid to high enough temperatures to produce steam. However, these complex systems can experience significant heat loss, leading to inefficient steam generation.

    Recently, scientists have explored ways to improve the efficiency of solar-thermal harvesting by developing new solar receivers and by working with nanofluids. The latter approach involves mixing water with nanoparticles that heat up quickly when exposed to sunlight, vaporizing the surrounding water molecules as steam. But initiating this reaction requires very intense solar energy — about 1,000 times that of an average sunny day.

    By contrast, the MIT approach generates steam at a solar intensity about 10 times that of a sunny day — the lowest optical concentration reported thus far. The implication, the researchers say, is that steam-generating applications can function with lower sunlight concentration and less-expensive tracking systems.

    “This is a huge advantage in cost-reduction,” Ghasemi says. “That’s exciting for us because we’ve come up with a new approach to solar steam generation.”

    From sun to steam

    The approach itself is relatively simple: Since steam is generated at the surface of a liquid, Ghasemi looked for a material that could both efficiently absorb sunlight and generate steam at a liquid’s surface.

    After trials with multiple materials, he settled on a thin, double-layered, disc-shaped structure. Its top layer is made from graphite that the researchers exfoliated by placing the material in a microwave. The effect, Chen says, is “just like popcorn”: The graphite bubbles up, forming a nest of flakes. The result is a highly porous material that can better absorb and retain solar energy.

    The structure’s bottom layer is a carbon foam that contains pockets of air to keep the foam afloat and act as an insulator, preventing heat from escaping to the underlying liquid. The foam also contains very small pores that allow water to creep up through the structure via capillary action.

    As sunlight hits the structure, it creates a hotspot in the graphite layer, generating a pressure gradient that draws water up through the carbon foam. As water seeps into the graphite layer, the heat concentrated in the graphite turns the water into steam. The structure works much like a sponge that, when placed in water on a hot, sunny day, can continuously absorb and evaporate liquid.

    The researchers tested the structure by placing it in a chamber of water and exposing it to a solar simulator — a light source that simulates various intensities of solar radiation. They found they were able to convert 85 percent of solar energy into steam at a solar intensity 10 times that of a typical sunny day.

    Ghasemi says the structure may be designed to be even more efficient, depending on the type of materials used.

    “There can be different combinations of materials that can be used in these two layers that can lead to higher efficiencies at lower concentrations,” Ghasemi says. “There is still a lot of research that can be done on implementing this in larger systems.”

    See the full article here.


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