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  • richardmitnick 10:57 am on May 23, 2018 Permalink | Reply
    Tags: Paving the way toward advanced computers lasers or optical devices, Quantum dots don’t always behave as expected, Quantum dots need to be close to perfect, Right now there are multiple sources of decoherence quantum dots, Strain game: Leveraging imperfections to create better-behaved quantum dots, U Wisconsin-Madison,   

    From University of Wisconsin Madison: “Strain game: Leveraging imperfections to create better-behaved quantum dots” 

    U Wisconsin

    From University of Wisconsin Madison

    May 17, 2018
    Sam Million-Weaver
    perspective@engr.wisc.edu

    1
    Postdoctoral scholar Anastasios Pateras adjust an X-Ray instrument used to detect previously unknown defects in quantum dots. Photo credit: Sam Million-Weaver.

    Potentially paving the way toward advanced computers, lasers or optical devices, University of Wisconsin-Madison researchers have revealed new effects in tiny electronic devices called quantum dots.

    In their work, published recently in the journal Nano Letters, the researchers developed and applied analysis methods that will help answer other challenging questions for developing electronic materials.

    “We can now look at a set of structures that people couldn’t look at before,” says Paul Evans, professor of materials science and engineering at UW-Madison. “In these structures, there are new sets of crucial materials problems that we previously weren’t able to think about solving.”

    The structures Evans and colleagues looked at are thousands of times narrower than single sheets of paper, and smaller than the dimensions of individual human cells. In those structures, quantum dots form inside very thin stacks of crystalline materials topped by an asymmetrical arrangement of flat, spindly, fingerlike metallic electrodes. Between the tips of those metallic fingers are small spaces that contain quantum dots.

    Creating such precise structures and peering inside those tiny spaces is technically challenging, however, and quantum dots don’t always behave as expected.

    Previous work by Evans’ collaborators at the Delft University of Technology in the Netherlands, who created and extensively studied the crystal stack structures, led to suspicions that the quantum dots were different in important ways from what had been designed.

    Until now, measuring those differences wasn’t possible.

    “Previous imaging approaches and the modeling weren’t allowing people to structurally characterize quantum dot devices at this tiny scale,” says Anastasios Pateras, a postdoctoral scholar in Evans’ group and the paper’s first author.

    Pateras and colleagues pioneered a strategy for using beams of very tightly focused X-rays to characterize the quantum dot devices—and that hinged on a new method for interpreting how the X-rays scattered. Using their approach, they observed shifts in the spacing and orientation of atomic layers within the quantum dots.

    “Quantum dots need to be close to perfect,” says Evans. “This small deviation from perfection is important.”

    The team’s discovery indicates that the process of creating the quantum dots—laying down metallic electrodes atop a lab-grown crystal—distorts the material underneath slightly. This puckering creates strain in the material, leading to small distortions in the quantum dots. Understanding and exploiting this effect could help researchers create better-behaved quantum dots.

    “Once you know these quantities, then you can design devices that take into account that structure,” says Evans.

    Designs with those small imperfections in mind will be especially important for future devices where many thousands of quantum dots must all work together.

    “This is going to be very relevant because, right now, there are multiple sources of decoherence quantum dots,” says Pateras.

    The researchers now are developing an algorithm to automatically visualize atomic positions in crystals from X-ray scattering patterns, given that performing the necessary calculations by hand would likely be too time-consuming. Additionally, they are exploring how the techniques could add insight to other hard-to study structures.

    The work was supported by the United States Department of Energy Basic Energy Sciences, Materials Sciences and Engineering (contract no. DE-FG02-04ER46147), the National Science Foundation Graduate Research Fellowship Program (grant no. DGE-1256259), and the Netherlands Organization of Scientific Research (NOW). Use of the Center for Nanoscale Materials and the Advanced Photon Source, both Office of Science user facilities, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (contract no. DE-AC02-06CH11357). Laboratory characterization at UW–Madison used instrumentation supported by the NSF through the UW–Madison Materials Research Science and Engineering Center (DMR-1121288 and DMR-1720415).

    See the full article here .


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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

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  • richardmitnick 12:14 pm on May 4, 2018 Permalink | Reply
    Tags: A novel prototype camera that will be used to image the fleeting signatures of gamma rays crashing into molecules of air in the Earth’s atmosphere creating a shower of diagnostic secondary particles, Cherenkov Telescope Array composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile, U Wisconsin-Madison   

    From University of Wisconsin Madison: “Prototype camera set for integration into novel gamma-ray telescope” 

    U Wisconsin

    University of Wisconsin Madison

    May 3, 2018
    Terry Devitt
    trdevitt@wisc.edu

    1
    Colin Adams, a UW–Madison physics undergraduate, makes an adjustment to a novel prototype camera that will be used to image the fleeting signatures of gamma rays crashing into molecules of air in the Earth’s atmosphere, creating a shower of diagnostic secondary particles. Credit: Savannah Guthrie.

    A unique high-speed camera, designed to capture the fleeting effects of gamma rays crashing into the Earth’s atmosphere, will soon be on its way from the University of Wisconsin–Madison to Arizona’s Mount Hopkins.

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Cherenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev

    There, the prototype camera will be integrated into a new telescope that will demonstrate novel technologies for the Cherenkov Telescope Array (CTA), a wide-ranging international effort to construct the world’s most advanced and comprehensive ground-based gamma-ray detector.

    “This telescope pushes the technology to a very different regime,” explains Vladimir Vassiliev, a professor of physics and astronomy at the University of California Los Angeles and the lead scientist for the telescope under construction on Mount Hopkins in southern Arizona. The telescope, he notes, will have unparalleled mirror optics and the camera is designed to capture the fleeting pulses of blue Cherenkov light created when gamma rays crash into molecules of air in Earth’s atmosphere, creating a shower of diagnostic secondary particles.

    “We’ll be able to make a movie at a billion frames per second of the particle shower developing in the atmosphere,” says Justin Vandenbroucke, the UW–Madison physics professor co-leading development of the prototype camera under the auspices of the Wisconsin IceCube Particle Astrophysics Center (WIPAC) with support from the National Science Foundation (NSF).

    American participation in CTA is supported by NSF, but the overarching project is a huge international undertaking and, when completed, will be comprised of more than 100 telescopes sited in the Canary Islands and Chile. It will be the largest ground-based gamma-ray detection observatory in the world. More than 1,400 scientists from 32 countries are involved in the undertaking. The camera and telescope are being funded primarily by NSF, with contributions from participating universities.

    With its innovative optics and camera, the new telescope will be operated in concert with an existing array of four single-mirror telescopes that comprise VERITAS (Very Energetic Radiation Imaging Telescope Array System), located at the Fred Lawrence Whipple Observatory on Mount Hopkins.

    CfA/VERITAS, a major ground-based gamma-ray observatory with an array of four 12m optical reflectors for gamma-ray astronomy in the GeV – TeV energy range. Located at FLWO in AZ, USA

    HESS Cherenkov Telescope Array, located on the Cranz family farm, Göllschau, in Namibia, near the Gamsberg searches for cosmic rays

    Camera technology is critical, says Vandenbroucke, who has been working on the design and construction of the 800-pound, golf-cart sized prototype instrument since 2009 when he was a post-doctoral fellow at Stanford University.

    The camera has finally come together in a basement laboratory in UW–Madison’s Chamberlin Hall, where Vandenbroucke’s group has been busy integrating and testing it. Camera components will be shipped May 7 to Arizona, where the camera will be reassembled, tested and integrated into the new telescope, which is now being fitted with its mirrors.

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    Sensors and electronic modules that are the heart of a prototype camera being integrated by UW–Madison physicists in support of the Cherenkov Telescope Array. The project is being facilitated by the Wisconsin IceCube Particle Astrophysics Center. Credit: Savannah Guthrie.

    The challenge for the camera, according to Vandenbroucke, is that the flashes of photons or particles of light that are of interest are incredibly fast. The Cherenkov pulse in an air shower may last only six nanoseconds, yet each pulse enables detection of a gamma-ray a trillion times more energetic than can be seen with the human eye. The pulses occur at random, making telescopes and cameras with wide fields of view essential, says Vassiliev.

    The combination of dual-mirror technology and the novel camera is intended to capture the Cherenkov air showers at unprecedented resolution. “This will be the first demonstration of this kind of optics for this kind of telescope,” says Vassiliev. “The payoff will be excellent imaging of Cherenkov air showers.”

    The gamma rays of interest to the CTA team span a wide range of energies. The telescope being built by Vassiliev’s team is designed to detect gamma rays in the central energy range. Objects powered by black holes, says Vandenbroucke, are among the likeliest sources of the gamma rays that will be parsed by the new CTA telescope.

    Opening a new frontier in the detection and measurement of gamma rays, says Vandenbroucke, will help answer a raft of some of the most fundamental questions about the nature of matter and energy in the universe. “Gamma rays are the linchpin of multi-messenger astronomy,” says the Wisconsin scientist. “They have been essential to identifying the first gravitational wave signal from merging neutron stars and may play a similar role in the search for the sources of high-energy neutrinos.”

    See the full article here .

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 12:52 pm on December 26, 2017 Permalink | Reply
    Tags: , , , J. William Schopf, John Valley, , , Oldest fossils ever found show life on Earth began before 3.5 billion years ago, SIMS-secondary ion mass spectrometer, Some represent now-extinct bacteria and microbes from a domain of life called Archaea, The study describes 11 microbial specimens from five separate taxa, U Wisconsin-Madison,   

    From U Wisconsin Madison and UCLA: “Oldest fossils ever found show life on Earth began before 3.5 billion years ago” 

    U Wisconsin

    University of Wisconsin

    UCLA bloc

    UCLA

    December 18, 2017
    Kelly April Tyrrell
    ktyrrell2@wisc.edu

    1
    Geoscience Professor John Valley, left, and research scientist Kouki Kitajima collaborate in the Wisconsin Secondary Ion Mass Spectrometer Lab (WiscSIMS) in Weeks Hall. Photo: Jeff Miller

    Researchers at UCLA and the University of Wisconsin–Madison have confirmed that microscopic fossils discovered in a nearly 3.5 billion-year-old piece of rock in Western Australia are the oldest fossils ever found and indeed the earliest direct evidence of life on Earth.

    2
    An epoxy mount containing a sliver of a nearly 3.5 billion-year-old rock from the Apex chert deposit in Western Australia is pictured at the Wisconsin Secondary Ion Mass Spectrometer Lab (WiscSIMS) in Weeks Hall. Photo: Jeff Miller

    The study, published Dec. 18, 2017 in the Proceedings of the National Academy of Sciences, was led by J. William Schopf, professor of paleobiology at UCLA, and John W. Valley, professor of geoscience at the University of Wisconsin–Madison. The research relied on new technology and scientific expertise developed by researchers in the UW–Madison WiscSIMS Laboratory.

    4
    J. William Schopf, U Wisconsin Madison

    5
    John Valley, UCLA

    2
    An example of one of the microfossils discovered in a sample of rock recovered from the Apex Chert. A new study used sophisticated chemical analysis to confirm the microscopic structures found in the rock are biological. Courtesy of J. William Schopf

    The study describes 11 microbial specimens from five separate taxa, linking their morphologies to chemical signatures that are characteristic of life. Some represent now-extinct bacteria and microbes from a domain of life called Archaea, while others are similar to microbial species still found today. The findings also suggest how each may have survived on an oxygen-free planet.

    The microfossils — so called because they are not evident to the naked eye — were first described in the journal Science in 1993 by Schopf and his team, which identified them based largely on the fossils’ unique, cylindrical and filamentous shapes. Schopf, director of UCLA’s Center for the Study of Evolution and the Origin of Life, published further supporting evidence of their biological identities in 2002.

    He collected the rock in which the fossils were found in 1982 from the Apex chert deposit of Western Australia, one of the few places on the planet where geological evidence of early Earth has been preserved, largely because it has not been subjected to geological processes that would have altered it, like burial and extreme heating due to plate-tectonic activity.

    But Schopf’s earlier interpretations have been disputed. Critics argued they are just odd minerals that only look like biological specimens. However, Valley says, the new findings put these doubts to rest; the microfossils are indeed biological.

    “I think it’s settled,” he says.

    Using a secondary ion mass spectrometer (SIMS) at UW–Madison called IMS 1280 — one of just a handful of such instruments in the world — Valley and his team, including department geoscientists Kouki Kitajima and Michael Spicuzza, were able to separate the carbon composing each fossil into its constituent isotopes and measure their ratios.

    Isotopes are different versions of the same chemical element that vary in their masses. Different organic substances — whether in rock, microbe or animal ­— contain characteristic ratios of their stable carbon isotopes.

    Using SIMS, Valley’s team was able to tease apart the carbon-12 from the carbon-13 within each fossil and measure the ratio of the two compared to a known carbon isotope standard and a fossil-less section of the rock in which they were found.

    “The differences in carbon isotope ratios correlate with their shapes,” Valley says. “If they’re not biological there is no reason for such a correlation. Their C-13-to-C-12 ratios are characteristic of biology and metabolic function.”

    Based on this information, the researchers were also able to assign identities and likely physiological behaviors to the fossils locked inside the rock, Valley says. The results show that “these are a primitive, but diverse group of organisms,” says Schopf.

    The team identified a complex group of microbes: phototrophic bacteria that would have relied on the sun to produce energy, Archaea that produced methane, and gammaproteobacteria that consumed methane, a gas believed to be an important constituent of Earth’s early atmosphere before oxygen was present.

    3
    UW–Madison geoscience researchers on a 2010 field trip to the Apex Chert, a rock formation in western Australia that is among the oldest and best-preserved rock deposits in the world. Courtesy of John Valley

    It took Valley’s team nearly 10 years to develop the processes to accurately analyze the microfossils — fossils this old and rare have never been subjected to SIMS analysis before. The study builds on earlier achievements at WiscSIMS to modify the SIMS instrument, to develop protocols for sample preparation and analysis, and to calibrate necessary standards to match as closely as possible the hydrocarbon content to the samples of interest.

    In preparation for SIMS analysis, the team needed to painstakingly grind the original sample down as slowly as possible to expose the delicate fossils themselves — all suspended at different levels within the rock and encased in a hard layer of quartz — without actually destroying them. Spicuzza describes making countless trips up and down the stairs in the department as geoscience technician Brian Hess ground and polished each microfossil in the sample, one micrometer at a time.

    Each microfossil is about 10 micrometers wide; eight of them could fit along the width of a human hair.

    Valley and Schopf are part of the Wisconsin Astrobiology Research Consortium, funded by the NASA Astrobiology Institute, which exists to study and understand the origins, the future and the nature of life on Earth and throughout the universe.

    Studies such as this one, Schopf says, indicate life could be common throughout the universe. But importantly, here on Earth, because several different types of microbes were shown to be already present by 3.5 billion years ago, it tells us that “life had to have begun substantially earlier — nobody knows how much earlier — and confirms it is not difficult for primitive life to form and to evolve into more advanced microorganisms,” says Schopf.

    Earlier studies by Valley and his team, dating to 2001, have shown that liquid water oceans existed on Earth as early as 4.3 billion years ago, more than 800 million years before the fossils of the present study would have been alive, and just 250 million years after the Earth formed.

    “We have no direct evidence that life existed 4.3 billion years ago but there is no reason why it couldn’t have,” says Valley. “This is something we all would like to find out.”

    UW–Madison has a legacy of pushing back the accepted dates of early life on Earth. In 1953, the late Stanley Tyler, a geologist at the university who passed away in 1963 at the age of 57, was the first person to discover microfossils in Precambrian rocks. This pushed the origins of life back more than a billion years, from 540 million to 1.8 billion years ago.

    “People are really interested in when life on Earth first emerged,” Valley says. “This study was 10 times more time-consuming and more difficult than I first imagined, but it came to fruition because of many dedicated people who have been excited about this since day one … I think a lot more microfossil analyses will be made on samples of Earth and possibly from other planetary bodies.”

    See the full U Wisconsin article here .
    See the full uCLA article by Stuart Wolpert here.
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    • stewarthoughblog 1:44 am on December 27, 2017 Permalink | Reply

      Schopf’s wishful speculation that what was discovered indicates life must be common is intellectually insulting with his failure that somehow live emerged rapidly, which strains the slow, methodical Darwinian theory of how life developed, given the relative complexity of the microorganisms. This is a wonderful discovery, but does nothing to solve the origin of life and raises serious questions about the power of naturalism to explain the origin of life as well as the rapid development of higher order complex organisms.

      The only extraterrestrial organisms that will be found will be those of Earth origin.

      Like

  • richardmitnick 4:09 pm on December 21, 2017 Permalink | Reply
    Tags: , Charles “Chuck” Konsitzke is the associate director of UW–Madison’s Biotechnology Center.Upon Mason’s diagnosis he began to delve into published NF1 research, , neurofibromatosis type 1, or NF1, Pigs are similar to humans in many ways that other common research animals such as mice and flies are not. That includes their size which means drugs and devices that work on humans can also be tested, There is no cure, U Wisconsin-Madison, With CRISPR the researchers believe they can take the genetic fingerprint of an individual child’s NF1 mutation and create a pig with that same mutation   

    From University of Wisconsin Madison: “To help kids battling a rare disease, scientists forge a genetic link between people and pigs” 

    U Wisconsin

    University of Wisconsin Madison

    December 19, 2017
    Kelly April Tyrrell
    ktyrrell2@wisc.edu

    1
    Mason Konsitzke, 7, plays in his bedroom at home in Stoughton. Photo: Jeff Miller

    Mason Konsitzke is 7. He loves food (especially when he can share it with others) and anything military (both of his grandfathers served). He likes to fly kites and play with his 5-year-old sister, Alexandra. But Mason was born with a disease called neurofibromatosis type 1, or NF1, and each day can present new challenges for him and his family.

    NF1 is a genetic disease caused by changes, or mutations, to a single gene in the human DNA library. Roughly one out of 3,000 babies born in the United States have the disease. That’s more than three times as many as have cystic fibrosis. Yet few people have ever heard of NF1.

    Mutations in the NF1 gene cause defects in the neurofibromin 1 protein, which acts as a tumor suppressor. Children with NF1 can develop painful tumors along their nerve tracts, including their skin and in their eyes. Sometimes this renders them blind. They are often diagnosed with autism spectrum disorder, though not all children with NF1 are also autistic, and they are sometimes diagnosed with attention deficit hyperactivity disorder. They may have soft bones that bend and break. They are at a higher risk for cancer. And there is no cure.

    It was not a disease Mason’s parents, Charles and Malia Konsitzke, had ever heard of. As a newborn, he was healthy. But when Mason was 6 months old, the couple began to suspect something was wrong. Mason developed coffee-and-cream-colored spots all over his body. His father later learned these were a hallmark of NF1. Mason received a genetic diagnosis of the disorder just before his first birthday.

    “We were like deer in the headlights,” Malia says. “We were in shock, wondering, what does this mean for us? What does it mean for Mason?”

    At 18 months, Mason began to lose his ability to speak. He was falling over, screaming constantly and deliberately banging his head. That’s when an MRI revealed a tumor called a plexiform neurofibroma in a mesh of nerves in the left side of his face. It was growing fast.

    A father turns to science

    Charles “Chuck” Konsitzke is the associate director of UW–Madison’s Biotechnology Center, a sort of one-stop shop for scientists in need of DNA sequencing, genome editing and other services.

    Upon Mason’s diagnosis he began to delve into published NF1 research. He wanted to know where it was happening, who was doing it and how he might be able to help. He sought opinions from experts, wondering how the field could be improved. Many identified the same bottleneck: the lack of a good research model.

    In biology, research models are animals, cells, plants, microbes and other living things that allow scientists to study biological processes and recreate diseases in order to better understand them. Good models yield information relevant to humans, but the right model can sometimes be difficult to find.

    2
    Seen through a microscope, a researcher guides a micro-needle (at right) to inject DNA into a pig embryo at UW–Madison’s Biotechnology Center. Photo: Jeff Miller

    NF1 is especially complex, affects many systems of the body and touches many areas of scientific inquiry, from cancer research to neurobiology. Chuck began to search for a better model and in 2013, when Mason was 3, he settled on pigs. Pigs are similar to humans in many ways that other common research animals, such as mice and flies, are not. That includes their size, which means drugs and devices that work on humans can also be tested on pigs. They have a robust immune system, which rodents lack. And they’re intelligent, so scientists can study changes to their cognition.

    Chuck then went on the hunt for researchers who studied swine.

    Braving the risks

    Dhanansayan “Dhanu” Shanmuganayagam, a nutrition and animal sciences professor in the UW–Madison College of Agricultural and Life Sciences, has spent most of his career using swine to study human diseases, particularly heart disease. In fact, he and colleagues in the animal sciences department created the Wisconsin Miniature Swine, a pig that, like people, can develop heart disease under the right conditions.

    Dhanu’s office was a few blocks from Chuck’s but they’d never met until a few years ago, when they bumped into one another while helping campaign for a new building on campus. They got to know one another and Chuck asked Dhanu whether he had ever heard NF1. He hadn’t. Chuck told him about Mason, about the need for a better model, about the promise that pigs offered to help understand and treat the disease. Would Dhanu join forces to help create that model, Chuck asked.

    Dhanu took some time to think about it. He consulted the members of his laboratory. All would be helping to forge this new path. His risks would be their risks. A pig model could fail, leading them all down a blind alley. That kind of outcome can derail a scientist’s entire career.

    Dhanu told Chuck he was in.

    The risks remain significant, he says, “but I’ve come to terms with it and it’s fine. I’ve been lucky in my career to work on things that have gone to clinic. If it works it’s going to be impactful.”

    Meanwhile, Chuck consulted a legal team to ensure he was clear of conflicts of interest, and took steps to ensure his involvement was ethical and not problematic for his staff at the Biotechnology Center.

    There aren’t many places in the world where this kind of work – melding basic science with clinical research and a large animal model like swine – is possible. UW–Madison has large biomedical research centers, the capacity for high-powered basic science, and a 1,500-pig research facility called the Swine Research and Teaching Center (SRTC), based in Arlington, a 35-minute drive from campus.

    “It’s a brave new frontier, to move into swine,” says David H. Gutmann, a physician and researcher at the Washington University School of Medicine in St. Louis, considered one of the foremost NF1 experts in the world. “I’m glad they’re doing this work at UW–Madison because the combination of specialized resources and expertise are found in very few places worldwide.”

    Like scissors for genes

    Dhanu and Chuck determined the course they wanted to chart included gene editing, using a powerful new tool known as CRISPR, which stands for Clustered Regularly Interspaced Short Palindromic Repeats.

    The genetic technology is reshaping basic biological research. Like a pair of molecular scissors, CRISPR enables scientists to target a stretch of cellular DNA for alteration. They can cut out pieces of DNA or swap out letters in the genome, changing the message it encodes or shutting off genes entirely.

    The two set their sights on creating pigs that carry the NF1 mutations they and other researchers are most interested in studying. “But we had to figure out where to start,” says Dhanu. “It’s like learning to fly a space shuttle.”

    With Dhanu’s lab manager and lead scientist Jen Meudt at the helm, the team dove in. But the challenges were many.

    They had to learn about swine reproduction, about CRISPR and gene editing, how to perform the necessary surgeries on pigs, how to time events so no step of the process failed and ruined all the efforts before it. Again and again, they hit roadblocks.

    It took more than a year, but finally, they came up with a plan: The researchers would use artificial insemination to impregnate a female pig carefully primed to produce more eggs than she naturally would. Shortly after fertilization, they would remove the embryos, whisk them to the Biotechnology Center and inject them with a solution containing the gene-editing CRISPR. This would have to be done quickly, while the embryos were still a single cell. When the single cell divided, all the subsequent cells would contain the NF1 mutation. Inject too late and the pig would develop into a mosaic of cells that contain the mutation and those that do not.

    Then it would be off to the surrogate mother, a pig chosen to reproductively match the embryo-donating pig. The researchers would perform surgery to implant the CRISPR embryos into her womb. If all went well, months later she would give birth to piglets, at least some of which would carry the desired NF1 mutations.

    A few months passed. On November 7, 2016, Chuck and Dhanu were meeting in Madison with a group from the Neurofibromatosis (NF) Network, which supports research and clinical care for NF1. They were sipping coffee when a text came in from Jen: “The mom carrying NF piglets is delivering right now.”

    The piglets – eight in all, and four with the NF1 mutation – were a living embodiment of the team’s hard work. They had proved that they could create pigs genetically-engineered to carry the disease. It was an emotional experience for the scientists, involving tears and prayers. They immediately went out to celebrate.

    Why are pigs used in research? Learn more

    Then they set to work building on that success. One of the four piglets with the mutation was a male. Mason named him Tank. His job is to sire more piglets with the mutation since the changes conferred by CRISPR were designed to be passed on from generation to generation.

    The team took the process they’d developed and applied it to other NF1 mutations, including some related to cancer. And they set an even more ambitious goal: precision medicine. A pig personalized for every child with NF1.

    With CRISPR, the researchers believe they can take the genetic fingerprint of an individual child’s NF1 mutation and create a pig with that same mutation. They can then test potential medications and treatments and see if they’ll work. Can tumors, like the one that afflicts Mason, be shrunk?

    The promise of precision

    By the time Mason reached pre-kindergarten, the tumor in his face had grown into his cranial sinus. His parents were told he could lose his sight and his ability to taste.

    Surgery wasn’t an option. It was too risky and could leave Mason in even greater pain, permanently. “He’s literally been in pain his whole life,” Malia says.

    Then, for reasons doctors couldn’t explain, the tumor stopped progressing. He regained his speech and no longer screamed or struggled to stay upright. His doctors keep a close watch on the tumor with MRI scans. And they continue to work to determine the best medication regimen for the other symptoms that come with his particular variant of NF1. His treatment must be continuously modified. Because of NF1’s unique manifestations, each child is an experiment unto himself.

    Pigs develop faster than children do so they offer the possibility of helping predict how NF1 might affect a particular child, enabling parents, doctors, teachers and others to prepare. Earlier intervention for a child who develops autism could lead to better outcomes. Doctors could start working to find drugs to treat tumors before they grow too large.

    “Precision medicine is more than matching the right drug to the right gene. With NF1 it’s more complicated and involves searching for the factors that make each individual with NF1 unique,” says Washington University’s David Gutmann. “This is an amazing opportunity to find the risk factors that put an affected child at risk for developing a brain tumor, a bone defect, or another serious complication of NF1.”

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    Washington University researcher David Gutmann, center, speaks with UW–Madison’s Dhanu Shanmuganayagam, left, and Neha Patel. Photo: Jeff Miller

    Dhanu, Chuck and Jen are not doing this work on their own. The team now includes many talented individuals like Biotechnology Center scientists C. Dustin Rubinstein, Kathy Krentz and Michael Sussman, along with Jamie Reichert and his team at the Swine Research and Teaching Center. And there’s now a broader research group, the UW NF1 Translational Research team, that includes Thomas Crenshaw, an animal sciences professor and department chair, and Marc Wolman, a professor of integrative biology.

    They have also enlisted the skill and knowledge of Neha Patel, a pediatrician at the University of Wisconsin School of Medicine and Public Health who treats about 150 children with NF1 in Wisconsin and surrounding regions.

    Dhanu hopes to make the NF1 pigs accessible to other researchers around the country, charging only what it costs to produce them. And the team plans to use the pigs to help identify metabolic and cellular pathways common to the variety of NF1 mutations, to help target and develop better drugs.

    But to accomplish all of this requires funding.

    “We’re at a critical moment,” Dhanu says. “We have to turn our successes into funding opportunities.”

    The UW NF1 Translational Research team has bootstrapped most of its work so far, relying primarily on funding and donations from the NF Network. Most of that comes from an annual charity golf tournament the Konsitzkes and four other families help organize and run. Called Links for Lauren, the tournament honors Lauren Geier, an 8-year-old girl in Madison with NF1.

    Families can play a surprisingly influential role in the fight against rare diseases.“They often provide critical resources and financial support at the earliest stages of a high-risk project, when funding from federal agencies is not possible,” says David Guttman. “Our families, they inspire us because they ask us to do things that are really meaningful and take risks by taking the roads not frequently traveled. Through their involvement they can move the field forward in ways that no one else can.”

    Where there’s research, there’s hope

    Larry Britzman had no idea there were pigs at UW–Madison that might one day help children like his 12-year-old daughter Mackenzie. He learned that, and much more, in May when he traveled to campus from La Valle, Wisconsin, for a symposium for patients and families.

    “I didn’t realize each child is specific,” he says. “I didn’t realize UW has swine research and there aren’t too many facilities in the country researching NF1.”

    The NF1 team hopes to host the symposium each year, to invite families to learn more about the science of NF1, to give them a chance to meet researchers and clinicians, and to ask questions and meet other families living with the disease.

    “We’ve gone very far in two years because it hasn’t been just about building a model, it’s also been about creating a community around it,” says Dhanu.

    The opportunity to work so closely with and on behalf of the people who may ultimately benefit from his work is not something he’d ever experienced. And it’s been profoundly rewarding.

    Not long ago, he invited a family whose college-aged daughter has NF1 into his lab. They’d been donors to NF1 causes for years but had never talked to a researcher. “It meant a lot to them and my first thought was: ‘How can we do more of this?’”

    He and his lab members now participate in running events like the Madison Half Marathon, often with The NF Team organization, to raise money for NF1 research and to increase awareness. The runners sport neon yellow performance shirts with bold, black lettering. They also participate in the annual charity golf tournament.

    “As scientists, we don’t often see the payoff of what we’re working on,” Dhanu says. “It redefines our research priorities and it also aids discovery. The best people to note observations are the people who live with it.”

    To him, success can be measured by individuals. “Even if our research just raises awareness and someone gets treated because of what we do, that alone is big,” he says.

    Chuck believes the disease is underdiagnosed because very few people are genetically tested for it and most physicians are not familiar with it. So they may diagnose patients with autism or a behavioral disorder and miss the broader picture.

    That has frustrated Danielle Wood, a teacher and mother of two who lives in Reedsburg, Wisconsin. Her daughter, Bernadette, is 2 and was diagnosed with NF1 as an infant. Along with springy blonde curls and an arresting smile, Bernadette has a weak abdominal wall, which causes her pain and may require surgery. She wears braces to support her frail ankles.

    Danielle, too, has NF1. Her mother had it and so did her grandmother. Though her condition is mild – she simply wears glasses for poor vision caused by a tumor on her optic nerve – deciding whether to have children was hard. Because it is a dominant mutation, Danielle and her husband had at least a 50 percent chance of giving birth to a baby with the disease. Having grown up with NF1, Danielle felt she had a good idea of what to expect. She now sees herself as an advocate for Bernadette.

    “While things never move as fast as we want them to, there’s a tremendous amount of exciting progress in this field and where there’s research, there’s hope,” says David Gutmann. UW–Madison is “in a really great position because (it has) young faculty who are excited and a patient community that is challenging them to improve the lives of people with NF1 through research.”

    This is what drives Chuck, Dhanu and the rest of the UW NF1 Translational Research team, which is working to establish a NF1 Center for Excellence at UW–Madison. Not only is this possible, David Gutmann says, it is necessary. “There is no established therapy for NF1 and no magic bullet that works for all kids or adults. The challenge for us is to learn more about this disorder so that personalized and effective treatments emerge.”

    Moreover, he says, what NF1 teaches researchers will inform their approaches to other conditions. And he’s excited to see what the future holds.

    “All of us in the NF field get up every morning and are excited to get to work. What we learn from our colleagues and our families each day brings us one step closer to that better future for children and adults with NF,” he says. “I can imagine getting up every morning and running to work to see what’s happening with those pigs.”

    For Mason, the pigs don’t play much of a role in his daily life today. Rather, he relies on regular visits to therapists and other professionals both in and out of school to help him manage his symptoms. He also benefits from the support of his family, from Chuck and Malia to aunts and uncles who have learned all they can about NF1. And the family dog, Donatella, is his packmate, Malia says.

    At 7, Mason can still take all that for granted. He can focus on what he loves best, like sharing the tastiest mini pizzas he can make. You should try the pepperoni.

    4
    Mason at home with his parents and sister Alexandra, 5. Photo: Jeff Miller

    See the full article here .

    Please help promote STEM in your local schools.

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 9:21 am on July 3, 2017 Permalink | Reply
    Tags: A new approach to combatting bacterial infections: Disrupting their communication, , , U Wisconsin-Madison   

    From U Wisconsin Madison: “A new approach to combatting bacterial infections: Disrupting their communication” 

    U Wisconsin

    University of Wisconsin – Madison

    June 19, 2017
    Will Cushman
    perspective@engr.wisc.edu

    1
    Collaborators David Lynn and Helen Blackwell, a professor of chemistry at UW-Madison, approach the control of bacterial infections not by blasting them with toxic antibiotics, but instead by inhibiting the ability of bacteria to become infectious in the first place.

    We call them “superbugs”—and antibiotic-resistant bacteria are literally an evolving threat. Doomsday prophets and other pessimists foresee a future where superbugs run amok, overwhelming doctors’ efforts to rid once easily treatable bacterial infections. Even optimists recognize the problem of antibiotic resistance as a serious public health threat. That’s why researchers around the world are looking for novel approaches to control bacterial infections, and one promising approach is taking shape in labs at UW-Madison.

    Collaborators David Lynn, the Duane H. and Dorothy M. Bluemke professor and Vilas Distinguished Achievement professor in chemical and biological engineering at UW-Madison, and Helen Blackwell, a professor of chemistry at UW-Madison, approach the control of bacterial infections not by blasting them with toxic antibiotics, but instead by inhibiting the ability of bacteria to become infectious in the first place.

    Many common species of bacteria, including those that cause dangerous infections, are actually fairly harmless at certain stages in their lifecycle. These bacteria become infectious—or virulent—only when they sense that their numbers have crossed a certain threshold. Once that threshold is crossed, a message travels through the colony, which signals that it’s time to go on the offense and infect their host. This communication process is called quorum sensing, and it’s a potential weak spot for bacteria.

    That’s because researchers are beginning to understand the mechanisms behind quorum sensing so well that they’ve been able to produce molecules that inhibit the process. It’s a potential breakthrough not only in preventing new infections, but also in potentially slowing the pace of antibiotic resistance. Quorum sensing inhibitors don’t kill bacteria—they simply render them impotent, allowing a host’s immune system to zap them before they become infectious.

    Antibiotic resistance is the product of the selective pressure of toxic drugs that kill most bacteria, leaving behind only those with resistant traits—however, quorum sensing inhibitors don’t kill bacteria and therefore should not create the selective pressure that leads to antibiotic resistance. Blackwell’s lab has successfully produced many different types of quorum sensing inhibitor molecules.

    Meanwhile, Lynn’s lab is developing novel methods for delivering these quorum sensing inhibitors to the body. New research published in the journal ACS Infectious Diseases describes their latest approach, using a technique called electrospinning that produces tiny nanofibers that contain the inhibitor molecules. “The technique involves passing a polymer solution through a needle,” says Lynn. “That needle has a large electrical potential, resulting in basically a jet of wildly fluctuating polymer solution from the tip of that needle. The dimensions of that jet just happen to be on the nanoscale.”

    The solvent then evaporates and leaves behind fibers with diameters on the order of several hundred nanometers. These fibers, which contain the inhibitor molecules can be collected as non-woven ‘mats’ or coatings on the surfaces of many kinds of materials, including common mesh-like wound dressings.

    Perhaps what makes the nanofiber delivery method most exciting is that the nanofibers control the release of the inhibitor molecules as they degrade.

    This timed release is a key goal of Lynn’s research as quorum sensing inhibitors aren’t much use if they don’t stick around long. The nanofibers in this current research have controlled release of the inhibitor for about two weeks, but some of Lynn’s other approaches have controlled release up to eight months.

    In addition to wound dressing applications, Lynn sees potential for the approach to be used in medical implant devices and both on its own or in concert with conventional antibiotics. He continues to work on other quorum sensing inhibitor delivery methods, and he and Blackwell are teaming up with researchers in the veterinary medicine and microbiology programs at UW-Madison to begin testing in mouse models.

    Still, Lynn cautions that it will be some time before quorum sensing inhibitors are part of doctors’ antibacterial armament. “This anti-virulence approach is brand new and there’s a lot of science that still needs to be understood,” Lynn says. “There’s a lot of work to do yet.”

    See the full article here .

    Please help promote STEM in your local schools.

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 7:56 am on March 28, 2017 Permalink | Reply
    Tags: , , , , , , U Wisconsin-Madison   

    From U Wisconsin via SURF : “Dark matter detection receives 10-ton upgrade” 

    SURF

    U Wisconsin

    University of Wisconsin

    1
    The LUX-ZEPLIN dark matter experiment will be located one mile underground at the Sanford Underground Research Facility in South Dakota, in a cavern within the former Homestake gold mine. Illustration: SLAC National Accelerator Laboratory


    Lux Zeplin project at SURF

    In an abandoned gold m­­­ine one mile beneath Lead, South Dakota, the cosmos quiets down enough to potentially hear the faint whispers of the universe’s most elusive material — dark matter.


    SURF bilding in Lead SD USA

    Shielded from the deluge of cosmic rays constantly showering the Earth’s surface, and scrubbed of noisy radioactive metals and gasses, the mine, scientists think, will be the ideal setting for the most sensitive dark matter experiment to date. Known as LUX-ZEPLIN, the experiment will launch in 2020 and will listen for a rare collision between a dark matter particle with 10 tons of liquid xenon.

    Ten University of Wisconsin–Madison scientists are involved in designing and testing the detector, and are part of a team of more than 200 researchers from 38 institutions in five countries working on the project. This month, the Department of Energy approved proceeding with the final stages of assembly and construction of LZ at the Sanford Underground Research Facility in South Dakota, with a total project cost of $55 million. Additional support comes from international collaborators in the United Kingdom, South Korea and Portugal, as well as the South Dakota Science and Technology Authority. The researchers’ goal is to take the experiment online as quickly as possible to compete in a global race to be the first to detect dark matter.

    3
    Scientists install a miniversion of the future LUX-ZEPLIN dark matter detector at a test stand. The white container is a prototype of the detector’s core. SLAC National Acceleratory Laboratory

    In the 1930s, as astronomers studied the rotation of distant galaxies, they noticed that there wasn’t enough matter — stars, planets, hot gas — to hold the galaxies together through gravity. There had to be some extra mass that helped bind all the visible material together, but it was invisible, missing.

    Dark matter, scientists believe, comprises that missing mass, contributing a powerful gravitational counterbalance that keeps galaxies from flying apart. Although dark matter has so far proven to be undetectable, there may be a lot of it — about five times more than regular matter.

    “Dark matter particles could be right here in the room streaming through your head, perhaps occasionally running into one of your atoms,” says Duncan Carlsmith, a professor of physics at UW–Madison.

    One proposed explanation for dark matter is weakly interacting massive particles, or WIMPs, particles that usually pass undetected through normal matter but which may, on occasion, bump into it. The LZ experiment, and similar projects in Italy and China, are designed to detect — or rule out — WIMPs in the search to explain this ghostly material.

    The detector is set up like an enormous bell capable of ringing in response to the lightest tap from a dark matter particle. Nestled within two outer chambers designed to detect and remove contaminating particles lies a chamber filled with 10 tons of liquid xenon. If a piece of dark matter runs into a xenon atom, the xenon will collide with its neighbors, producing a burst of ultraviolet light and releasing electrons.

    Moments later, the free electrons will excite the xenon gas at the top of the chamber and release a second, brighter burst of light. More than 500 photomultiplier tubes will watch for these signals, which together can discriminate between a contaminating particle and true dark matter collisions.

    Kimberly Palladino, an assistant professor of physics at UW–Madison, and graduate student Shaun Alsum were part of the research team for LUX, the predecessor to LZ, which set records searching for WIMPs. Building on their experience from the previous experiment, Palladino, Alsum, graduate student Jonathan Nikoleyczik and undergraduate researchers are conducting simulations of dark matter collisions and prototyping the particle detector to increase the sensitivity of LZ and more stringently discard signals produced by ordinary matter.

    3
    The heart of the LZ detector will be a 5-foot-tall chamber filled with 10 tons of liquid xenon. Hopes are that hypothetical dark matter particles will produce flashes of light as they traverse the detector. Illustration: SLAC National Accelerator Laboratory

    The LZ project is “doing science the way you want to do science,” says Palladino, explaining how the collaboration provides the time, funding and expertise needed to address fundamental questions about the nature of the universe.

    The success of LZ depends in part on excluding contaminating materials, including reactive chemicals and trace amounts of radioactive elements, from the xenon, which relies on engineering prowess provided by UW–Madison’s Physical Sciences Laboratory. Jeff Cherwinka, chief engineer of the LZ project and a PSL mechanical engineer, is overseeing assembly of the dark matter detector in a special facility scrubbed of radioactive radon and is designing a system to continuously remove gas that leaches out of the xenon chamber lining. Together with PSL engineer Terry Benson, Cherwinka is also designing the xenon storage system to prevent any radioactive elements from leaking in during transport and installation.

    “It’s one of the strengths of the university that we have the engineering and manufacturing expertise to contribute to these big-scale projects,” says Cherwinka. “It helps UW gain more stake in these projects.”

    Meanwhile, Carlsmith and Sridhara Dasu, also a UW–Madison professor of physics, are designing computational systems to manage and analyze the data coming out of the detector in order to be ready to listen for dark matter collisions as soon as LZ is turned on in 2020. Once operational, LZ will quickly approach the fundamental limit of its detection capacity, the background noise of particles streaming out of the sun.

    4
    Kimberly Palladino, an assistant professor of physics at UW–Madison, works to assemble a prototype of the dark matter detection chamber. SLAC National Accelerator Laboratory.

    “In a year, if there are no WIMPs, or if they interact too weakly, we’ll see nothing,” says Carlsmith. The experiment is expected to operate for at least five years to confirm any initial observations and set new limits on potential interactions between WIMPs and ordinary matter.

    Other experiments, including Wisconsin IceCube Particle Astrophysics Center projects IceCube, HAWC, and CTA, are searching for the signatures of dark matter annihilation events as independent and indirect methods to investigate the nature of dark matter. In addition, UW–Madison scientists are working at the Large Hadron Collider, searching for evidence that dark matter is produced during high energy particle collisions. This combination of efforts provides the best opportunity yet for uncovering more about the nature of dark matter, and with it the evolution and structure of our universe.

    See the full article here .

    Please help promote STEM in your local schools.

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 5:35 am on September 6, 2016 Permalink | Reply
    Tags: , Carbon nanotube transistors, , , U Wisconsin-Madison   

    From U Wisconsin: “First time, carbon nanotube transistors outperform silicon” 

    U Wisconsin

    University of Wisconsin

    September 2, 2016
    Adam Malecek

    1
    The UW–Madison engineers use a solution process to deposit aligned arrays of carbon nanotubes onto 1 inch by 1 inch substrates. The researchers used their scalable and rapid deposition process to coat the entire surface of this substrate with aligned carbon nanotubes in less than 5 minutes. The team’s breakthrough could pave the way for carbon nanotube transistors to replace silicon transistors, and is particularly promising for wireless communications technologies. Stephanie Precourt

    For decades, scientists have tried to harness the unique properties of carbon nanotubes to create high-performance electronics that are faster or consume less power — resulting in longer battery life, faster wireless communication and faster processing speeds for devices like smartphones and laptops.

    But a number of challenges have impeded the development of high-performance transistors made of carbon nanotubes, tiny cylinders made of carbon just one atom thick. Consequently, their performance has lagged far behind semiconductors such as silicon and gallium arsenide used in computer chips and personal electronics.

    Now, for the first time, University of Wisconsin–Madison materials engineers have created carbon nanotube transistors that outperform state-of-the-art silicon transistors.

    Led by Michael Arnold and Padma Gopalan, UW–Madison professors of materials science and engineering, the team’s carbon nanotube transistors achieved current that’s 1.9 times higher than silicon transistors. The researchers reported their advance in a paper published Friday (Sept. 2) in the journal Science Advances.

    “This achievement has been a dream of nanotechnology for the last 20 years,” says Arnold. “Making carbon nanotube transistors that are better than silicon transistors is a big milestone. This breakthrough in carbon nanotube transistor performance is a critical advance toward exploiting carbon nanotubes in logic, high-speed communications, and other semiconductor electronics technologies.”

    This advance could pave the way for carbon nanotube transistors to replace silicon transistors and continue delivering the performance gains the computer industry relies on and that consumers demand. The new transistors are particularly promising for wireless communications technologies that require a lot of current flowing across a relatively small area.

    As some of the best electrical conductors ever discovered, carbon nanotubes have long been recognized as a promising material for next-generation transistors.

    Carbon nanotube transistors should be able to perform five times faster or use five times less energy than silicon transistors, according to extrapolations from single nanotube measurements. The nanotube’s ultra-small dimension makes it possible to rapidly change a current signal traveling across it, which could lead to substantial gains in the bandwidth of wireless communications devices.

    But researchers have struggled to isolate purely carbon nanotubes, which are crucial, because metallic nanotube impurities act like copper wires and disrupt their semiconducting properties — like a short in an electronic device.

    The UW–Madison team used polymers to selectively sort out the semiconducting nanotubes, achieving a solution of ultra-high-purity semiconducting carbon nanotubes.

    “We’ve identified specific conditions in which you can get rid of nearly all metallic nanotubes, where we have less than 0.01 percent metallic nanotubes,” says Arnold.

    Placement and alignment of the nanotubes is also difficult to control.

    To make a good transistor, the nanotubes need to be aligned in just the right order, with just the right spacing, when assembled on a wafer. In 2014, the UW–Madison researchers overcame that challenge when they announced a technique, called “floating evaporative self-assembly,” that gives them this control.

    The nanotubes must make good electrical contacts with the metal electrodes of the transistor. Because the polymer the UW–Madison researchers use to isolate the semiconducting nanotubes also acts like an insulating layer between the nanotubes and the electrodes, the team “baked” the nanotube arrays in a vacuum oven to remove the insulating layer. The result: excellent electrical contacts to the nanotubes.

    The researchers also developed a treatment that removes residues from the nanotubes after they’re processed in solution.

    “In our research, we’ve shown that we can simultaneously overcome all of these challenges of working with nanotubes, and that has allowed us to create these groundbreaking carbon nanotube transistors that surpass silicon and gallium arsenide transistors,” says Arnold.

    The researchers benchmarked their carbon nanotube transistor against a silicon transistor of the same size, geometry and leakage current in order to make an apples-to-apples comparison.

    They are continuing to work on adapting their device to match the geometry used in silicon transistors, which get smaller with each new generation. Work is also underway to develop high-performance radio frequency amplifiers that may be able to boost a cellphone signal. While the researchers have already scaled their alignment and deposition process to 1 inch by 1 inch wafers, they’re working on scaling the process up for commercial production.

    Arnold says it’s exciting to finally reach the point where researchers can exploit the nanotubes to attain performance gains in actual technologies.

    “There has been a lot of hype about carbon nanotubes that hasn’t been realized, and that has kind of soured many people’s outlook,” says Arnold. “But we think the hype is deserved. It has just taken decades of work for the materials science to catch up and allow us to effectively harness these materials.”

    The researchers have patented their technology through the Wisconsin Alumni Research Foundation.

    Funding from the National Science Foundation, the Army Research Office and the Air Force supported their work.

    Additional authors on the paper include Harold Evensen, a University of Wisconsin-Platteville engineering physics professor, Gerald Brady, a UW–Madison materials science and engineering graduate student and lead author on the study, and graduate student Austin Way and postdoctoral researcher Nathaniel Safron.

    See the full article here .

    Please help promote STEM in your local schools.

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 10:07 am on August 4, 2016 Permalink | Reply
    Tags: , , , U Wisconsin-Madison   

    From U Wisconsin: “Tiny high-performance solar cells turn power generation sideways” 

    U Wisconsin

    University of Wisconsin

    August 3, 2016
    Sam Million-Weaver

    1
    Hongrui Jiang inspects the alignment of a light source to illuminate new-generation lateral solar cells. The solar cells developed by Jiang’s group harvest almost three times more electricity from incoming light as compared to existing technologies. Photo: Stephanie Precourt

    University of Wisconsin—Madison engineers have created high-performance, micro-scale solar cells that outshine comparable devices in key performance measures. The miniature solar panels could power myriad personal devices — wearable medical sensors, smartwatches, even autofocusing contact lenses.

    Large, rooftop photovoltaic arrays generate electricity from charges moving vertically. The new, small cells, described today (Aug. 3, 2016) in the journal Advanced Materials Technologies, capture current from charges moving side-to-side, or laterally. And they generate significantly more energy than other sideways solar systems.

    New-generation lateral solar cells promise to be the next big thing for compact devices because arranging electrodes horizontally allows engineers to sidestep a traditional solar cell fabrication process: the arduous task of perfectly aligning multiple layers of the cell’s material atop one another.

    “From a fabrication point of view, it is always going to be easier to make side-by-side structures,” says Hongrui Jiang, a UW–Madison professor of electrical and computer engineering and corresponding author on the paper. “Top-down structures need to be made in multiple steps and then aligned, which is very challenging at small scales.”

    Lateral solar cells also offer engineers greater flexibility in materials selection.

    Top-down photovoltaic cells are made up of two electrodes surrounding a semiconducting material like slices of bread around the meat in a sandwich. When light hits the top slice, charge travels through the filling to the bottom layer and creates electric current.

    In the top-down arrangement, one layer needs to do two jobs: It must let in light and transmit charge. Therefore, the material for one electrode in a typical solar cell must be not only highly transparent, but also electrically conductive. And very few substances perform both tasks well.

    Instead of building its solar cell sandwich one layer at a time, Jiang’s group created a densely packed, side-by-side array of miniature electrodes on top of transparent glass. The resulting structure — akin to an entire loaf of bread’s worth of solar-cell sandwiches standing up sideways on a clear plate — separates light-harvesting and charge-conducting functions between the two components.

    Generally, synthesizing such sideways sandwiches is no simple matter. Other approaches that rely on complicated internal nanowires or expensive materials called perovskites fall short on multiple measures of solar cell quality.

    “We easily beat all of the other lateral structures,” says Jiang.

    Existing top-of the-line lateral new-generation solar cells convert merely 1.8 percent of incoming light into useful electricity. Jiang’s group nearly tripled that measure, achieving up to 5.2 percent efficiency.

    “In other structures, a lot of volume goes wasted because there are no electrodes or the electrodes are mismatched,” says Jiang. “The technology we developed allows us to make very compact lateral structures that take advantage of the full volume.”

    Packing so many electrodes into such a small volume boosted the devices’ “fill factors,” a metric related to the maximum attainable power, voltage and current. The structures realized fill factors up to 0.6 — more than twice the demonstrated maximum for other lateral new-generation solar cells.

    Jiang and colleagues are working to make their solar cells even smaller and more efficient by exploring materials that further optimize transparency and conductivity. Ultimately they plan to develop a small-scale, flexible solar cell that could provide power to an electrically tunable contact lens.

    Other authors on the paper included Xi Zhang, Yinggang Huang, Hao Bian, Hewei Liu, and Xuezhen Huang. The National Institutes of Health provided funding for the research.

    See the full article here .

    Please help promote STEM in your local schools.

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 4:46 pm on July 25, 2016 Permalink | Reply
    Tags: 3-D printing, , , , U Wisconsin-Madison   

    From U Wisconsin: “Tiny 3-D models may yield big insights into ovarian cancer” 

    U Wisconsin

    University of Wisconsin

    July 25, 2016
    Will Cushman
    perspective@engr.wisc.edu

    With a unique approach that draws on 3-D printing technologies, a team of University of Wisconsin–Madison researchers is developing new tools for understanding how ovarian cancer develops in women.

    About 1.5 percent of American women will be diagnosed with ovarian cancer, but most of them will not be diagnosed until late in the disease’s progression — after the cancer has spread to other parts of the body. This is reflected in the grim outlook for most women: The five-year survival rate for ovarian cancer is about 25 percent.

    Paul Campagnola, a professor of biomedical engineering and medical physics at UW–Madison, leads a group of researchers aiming to improve that outlook by understanding how ovarian cancer cells interact with nearby body tissue, and by developing new tools for imaging and detecting the disease. With a $2 million grant from the National Institutes of Health, they will use technology they’ve developed on the UW–Madison campus to develop images of tissues from surgical patients. The first target is collagen, a common protein that gives much of the body structure by holding bones, ligaments and muscles together.

    1
    A normal ovarian epithelial cell clings to a tiny model of an ovarian cancer tumor made with a 3-D printer. The tumor models will help scientists study ovarian cancer in mice, which do not naturally develop the disease. Image courtesy of Paul Campagnola

    “In most cancers, including ovarian, there are large changes in the collagen structure that goes along with the disease,” Campagnola says. “It might happen first. It might be later. It’s actually not known.”

    Campagnola and his colleagues, including Kevin Eliceiri, director of UW–Madison’s Laboratory for Optical and Computational Instrumentation, and Manish Patankar, associate professor of obstetrics and gynecology, hope to eliminate that unknown by printing tiny, 3-D models of the collagen samples.

    The models will be biomimetic — synthetic, but mimicking biological materials, as Velcro mimics the burs of a plant — and extremely small. Because, after seeding the models with ovarian cancer cells, the researchers will implant them into mice.

    Why not simply inject the mice with cancer cells and skip the painstaking imaging and 3-D printing process? Mice don’t get ovarian cancer — a partial answer for why we still don’t understand ovarian cancer as well as many other cancers.

    “The current way that people study ovarian cancer in a mouse is very poor,” Campagnola explains. “They just take human cell lines and then inject them into a mouse. Then some of them will form into a tumor, but most do not.”

    By implanting a 3-D tissue model seeded with ovarian cancer into mice, Campagnola hopes to mimic more closely the conditions of metastatic ovarian cancer in humans.

    “What’s different is our tissues will already be 3-D structured,” Campagnola says. “One problem when people study cancer sometimes is that they put cells in a dish. Cells in a dish don’t act like cells in tissue. So we’re trying to give them the tissue structure that cancer cells would have in a native environment.”

    From there, they’ll study how the implanted tumors grow inside the mice, and hopefully begin to learn more about the cues and processes involved in the disease’s progression and spread.

    It’s an approach that no one has ever attempted, one that will also help improve the way doctors make images of ovaries inside the body.

    “It’s an integrated approach to improving our imaging capabilities, but then also using our imaging capabilities to make these models so we can study the biology,” Campagnola says.

    Ultimately, the team’s long-term goal is to improve screening, diagnosis and treatment of ovarian cancer. One of the most effective ways to improve the outlook for women with ovarian cancer is to develop a straightforward method for screening women at higher risk for the disease. Women with a mutation in a gene called BRCA — a mutation also implicated in a higher risk for breast cancer — have a 40 percent chance of developing ovarian cancer in their lifetime.

    “Those are the women we really want to follow,” Campagnola says. “You could imagine — we’re a long way off from this — screening those women every few years with a minimally invasive device through a laparoscope or through the fallopian tubes.”

    But to get to that point, Campagnola says, researchers need to know a lot more about how ovarian cancer works.

    “You have to know what you’re looking for,” he says. “That’s why we have all this more basic work to do to get to that point. That’s why we need better imaging tools and we need better models to understand the biology of the disease.”

    See the full article here .

    Please help promote STEM in your local schools.

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
  • richardmitnick 5:44 am on July 23, 2016 Permalink | Reply
    Tags: , , , U Wisconsin-Madison   

    From U Wisconsin: “New UW-Madison center offers ultra-speed protein analysis” 

    U Wisconsin

    University of Wisconsin

    July 22, 2016
    David Tenenbaum
    djtenenb@wisc.edu

    1
    UW-Madison undergraduate Kyle Connors operates a mass spectrometer in the new NIH National Center for Quantitative Biology at UW–Madison. Photo: Nick Wilkes

    Three University of Wisconsin—Madison researchers have won a prestigious, five-year grant to establish the National Center for Quantitative Biology of Complex Systems, which will develop next-generation protein measurement technologies and offer them to biologists nationwide.

    It is proteins that do the work in the body: Hemoglobin, for example, holds oxygen for transport in the blood stream, while insulin helps regulate sugar in the blood. Knowing which protein forms are present in what quantities, their subcellular location and their function is critical to understanding health and disease.

    The scientific technique of mass spectrometry, or mass spec, can already recognize proteins, but the researchers are eying a speed-up akin to that which revolutionized genetics research over the past 20 years.

    Genes are vital carriers of information and templates for proteins, says co-investigator David Pagliarini, a UW–Madison professor of biochemistry. But genes alone don’t explain everything.

    There is lot of action between the gene, the protein it patterns, and the actual biological result,” he explains. “Mass spec technology allows you to measure the proteins, which are closer to action, and we plan to push the limits on pace, depth, throughput.”

    The center, funded at $6 million by the National Institutes of Health (NIH), will develop and make available advanced protein measurement technologies, says Josh Coon, a UW–Madison professor of biomolecular chemistry and an expert in mass spec. “These are complicated, high-end instruments that hundreds or thousands of biomedical researchers who are funded by the NIH need access to. There are many problems that are not solved with current technology, and that high-throughput mass spec can address.”

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    A modified orbitrap mass spectrometer in the Coon Laboratory. The modifications illuminate trapped protein ions with infrared photons, providing the basis of a new protein sequencing technology. Photo: Nick Wilkes

    Two among the many areas of interest concern lung cancer and diabetes, Coon says. “We have researchers who want to examine proteins related to the function — or failure — of the pancreatic cells that make insulin.”

    The center will serve as a training ground in mass spec and a laboratory to invent new techniques and equipment. One tactic to be explored relies on parallel processing, an approach like the one that fed a revolution in gene sequencing.

    Co-investigator Lingjun Li, a UW–Madison professor of pharmacy, will develop chemical markers to identify individual samples after they are mixed for mass spec analysis. In a similar vein, Coon will explore “metabolic tags” composed of amino acids that enter proteins after being eaten by lab animals.

    “We are not developing technology in a vacuum,” says Li, “but with specific biomedical needs in mind. Our methods will be broadly available to NIH researchers, and they will be the test bed that validates our methods.”

    Pagliarini says he will serve as “a bridge between technology development and biological applications. Our future collaborators have told us there are certain problem out there waiting for a solution in new technology.”

    “The NIH wants the center to invent and disseminate technologies,” says Coon. “We hope to do for proteins what high-throughput sequencing has done for genomic studies.”

    See the full article here .

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    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
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