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  • richardmitnick 4:01 pm on May 22, 2016 Permalink | Reply
    Tags: , Nanotechnology,   

    From SA: “Nanosized Materials Help Electronics Compute Like Real Brains” 

    Scientific American

    Scientific American

    May 20, 2016
    Michael Torrice, Chemical & Engineering News

    1
    Credit: Eyewire/Getty Images (MARS)

    Although processors have gotten smaller and faster over time, few computers can compete with the speed and computing power of the human brain. And none comes close to the organ’s energy efficiency. So some engineers want to develop electronics that mimic how the brain computes to build more powerful and efficient devices.

    A team at IBM Research, Zurich, now reports that nanosized devices made from phase-change materials can mimic how neurons fire to perform certain calculations (Nat. Nanotechnol. 2016, DOI:10.1038/nnano.2016.70).

    This report “shows quite concretely that we can make simple but effective hardware mimics of neurons, which could be made really small and therefore have low operating powers,” says C. David Wright, an electrical engineer at the University of Exeter who wrote a commentary accompanying the new article.

    The IBM team’s device imitates how an individual neuron integrates incoming signals from other neurons to determine when it should fire. These input signals change the electrical potential across the neuron’s membrane—some increase it, others decrease it. Once that potential passes a certain threshold, the neuron fires.

    Previously, engineers have mimicked this process using combinations of capacitors and silicon transistors, which can be complex and difficult to scale down, Wright explains in his commentary.

    In the new work, IBM’s Evangelos Eleftheriou and colleagues demonstrate a potentially simpler system that uses a phase-change material to play the part of a neuron’s membrane potential. The doped chalcogenide Ge2Sb2Te5, which has been tested in conventional memory devices, can exist in two phases: a glassy amorphous state and a crystalline one. Electrical pulses slowly convert the material from amorphous to crystalline, which, in turn, changes its conductance. At a certain level of phase change, the material’s conductance suddenly jumps, and the device fires like a neuron.

    The IBM team tested a mushroom-shaped device consisting of a 100-nm-thick layer of the chalcogenide sandwiched between two electrodes. In one demonstration, they used the neuronlike device to detect correlations in 1,000 streams of binary data. Such a calculation could spot trends in social media chatter or even in stock market transactions, Wright says.

    He also points out that the devices fire faster than actual neurons, on a nanosecond timescale compared with a millisecond one. The neuron mimics, Wright says, are another step toward hardware that can process information as the brain does but at speeds orders of magnitudes faster than the organ. “That could do some remarkable things.”

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  • richardmitnick 6:13 pm on May 16, 2016 Permalink | Reply
    Tags: Nanotechnology, , , MIT.nano rising   

    From MIT: “MIT.nano rising” 

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    MIT News
    MIT Widget

    1
    MIT.nano steel structure, looking northwest. Photo: Lillie Paquette/School of Engineering

    2
    MIT.nano steelworkers. Photo: Lillie Paquette/School of Engineering

    April 20, 2016 [Just appeared in social media.]

    MIT’s future home for cutting-edge nanoscience and nanotechnology research gets fitted with 23 tons of steel per day.

    A spectacular show has been going on outside the windows of central-campus buildings all spring. An enormous steel structure has been growing — piece by piece, and bolt by bolt — out of a giant hole in the ground formerly occupied by Building 12. At a March 24 “tool talk” information session for the MIT community on the construction of MIT.nano, representatives from MIT Facilities and the contractors who are building the new 200,000 square foot nanoscale characterization and fabrication facility gave an overview not only of where things stand with the project, but how they got stood up.

    “In our structural-steel erection progress log, we’ve been averaging around 23 tons per day,” said Peter Johnson of Turner Construction. “We’re putting up 2,101 tons total, and we’re 22 percent complete.”

    On day 469 of the 1,000 days of construction for the project, about 75 percent of the first level was complete, and a quarter of the level 3 cleanroom was installed down to the floor decking. The framing for the entire structure, which will reach a final height of 90 feet above grade, is scheduled to be complete by late May. To get there, Johnson and others have spent years organizing and refining a minutely detailed project plan that links engineering design and fabrication, and the installation process. They have had to map out construction logistics on an hour-to-hour, and foot-by-foot basis. It all must be calibrated to unfold within specific timelines and within the tight confines of MIT.nano’s central campus location. “There’s not a lot of space when it comes to material handling and the movement of workers,” Johnson noted.

    Decisions about cranes, Johnson said, were particularly critical. “While we could have used a single crane to reach the entire footprint, it was too slow. We have a several thousand line item project schedule with hundreds of steel-related tasks,” Johnson explained. “So having two cranes for a shorter period of time made the job more efficient.”

    The first crane was erected during the excavation phase, so workers could use it to lower concrete and rebar into the excavated hole for elements of the foundation. The next crane arrived just prior to steel installation. Positioned strategically in locations that do not block truck routes, the cranes hoist pre-fabricated, specially packaged bundles of steel into the specific locations where they will be needed for construction. Within these packages, each piece has a number that corresponds to its function and placement, and each one has been specifically manufactured for its location, with features like pre-drilled holes to accommodate plumbing and electrical connections. (“So someone knows where the number goes, and that side A connects to side B?” asked Vladimir Bulovic, the faculty lead on the design and construction of MIT.nano. “Just like my Ikea furniture, but bigger.” The construction experts did not dismiss the comparison.)

    Working with Ontario-based steel fabricator, Canatal, Johnson and his colleagues at Turner developed a four-dimensional plan for steel engineering, delivery, and installation. “We went through a painstaking process to maximize efficiency of this sequence,” says Johnson. “This allows us to avoid times when a crane is down because it’s waiting” for a delivery of steel.

    As the structure grows, engineers continuously monitor the basement walls and foundation of the structure with inclinometers, a seismograph, and a three-dimensional laser scanner to gauge how they are responding to the additional weight of the steel. The corner braces in the building’s 50-foot-deep excavation that counteract pressure coming from outside the walls will be removed after the steel is finished and concrete is poured on the building’s first floor. “The building is performing the way we expected it to,” said Richard Amster, director of campus construction.

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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 9:40 pm on May 9, 2016 Permalink | Reply
    Tags: , Nanotechnology, Ohio U   

    From Ohio University: “Scientists develop synchronized molecular motors” 

    Ohio U bloc

    Ohio University

    May 9, 2016
    Saw-Wai Hla
    (740) 593-1718
    hla@ohio.edu

    Andrea Gibson,
    (740) 597-2166
    gibsona@ohio.edu

    Jennifer Hughes,
    (740) 597-1939
    hughesj2@ohio.edu

    1
    (Top) This illustration shows parallel motors with dipolar rotator arms indicated by arrows. The green and red units represent negative and positive charges. (Bottom) Scanning tunneling microscope image showing a parallel arrangement of dipolar motor assembly. Image credit: Saw-Wai Hla

    An international team of scientists has created molecular motors that can communicate and synchronize their movements.

    The team, led by physicist Saw-Wai Hla of Ohio University, published* an Advanced Online Publication today in the journal Nature Nanotechnology demonstrating that scientists can control the coordinated motions of tiny machines at the nanoscale. The research has implications for the future development of technologies that can be used in computers, photonics and electronics as well as novel nanoscale devices.

    “Our goal is to mimic natural biological machines by creating synthetic machines we can control,” said Hla, a professor of physics and astronomy.

    Hla’s team observed up to 500 molecular motors move simultaneously in the same direction when the scientists applied 1 volt of energy through the tip of a scanning tunneling microscope. At lower levels of energy, the motors also rotated, but in different directions. However, this motion was not random, but showed patterns of coordination, Hla said.

    In the experiment, scientists observed the synchronized movements at minus 316 degrees Fahrenheit.

    The motors have two decks: The upper deck is the rotor and the lower deck is the stator, which has eight sulfur atoms that act as atomic glue to stick to surfaces of gold or copper. The rotating and stationary decks are connected with an atom of europium that serves as an atomic ball bearing.

    Scientists at CEMES/CNRS in France synthesized the molecular motors, which include a dipole in the rotor arms, which means that they have a positive and negative side. This unique feature allows the individual motors to communicate and coordinate their motions, Hla’s team found.

    In addition, the scientists learned that a hexagon arrangement of the motors is key for the synchronization, as it allows the motors to effectively communicate.

    The molecular motors create a ferroelectric system, which is a prized property of materials used in various electronic devices, Hla added.

    The nanomotors are so small that scientists can fit 44,000 billion of them in a 1 centimeter square area.

    “One of the goals of nanotechnology is to assemble billions of nanomachines packed into a tiny area that can be operated in a synchronized manner to transport information or to coherently transfer energy to multiple destinations within nanometer range,” Hla explained.

    The Ohio team received funding from the U.S. Department of Energy and the French team is supported by the French National Research Agency.

    Ohio University team members on the study were S.-W. Hla, Y. Zhang, H. Kersell, V. Iancu, U.G.E. Perera, Y. Li, A. Deshpande and K.-F. Braun of the Department of Physics and Astronomy and Nanoscale and Quantum Phenomena Institute. Hla also is the head of the Quantum and Energy Materials research group at the Center for Nanoscale Materials in Argonne National Laboratory. C. Joachim, R. Stefak and J. Echeverria of CEMES/CNRS in France and G. Rapenne of CEMES/CNRS and the University of Toulouse in France collaborated on the study.

    *Science paper:
    Simultaneous and coordinated rotational switching of all molecular rotors in a network

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    Ohio U campus

    n 1786, 11 men gathered at the Bunch of Grapes Tavern in Boston to propose development of the area north of the Ohio River and west of the Allegheny Mountains known then as the Ohio Country. Led by Manasseh Cutler and Rufus Putnam, the Ohio Company petitioned Congress to take action on the proposed settlement. The eventual outcome was the enactment of the Northwest Ordinance of 1787, which provided for settlement and government of the territory and stated that “…schools and the means of education shall forever be encouraged.”

    In 1803, Ohio became a state and on February 18, 1804, the Ohio General Assembly passed an act establishing “The Ohio University.” The University opened in 1808 with one building, three students, and one professor, Jacob Lindley. One of the first two graduates of the University, Thomas Ewing, later became a United States senator and distinguished himself as cabinet member or advisor to four presidents.

    Twenty-four years after its founding, in 1828, Ohio University conferred an A.B. degree on John Newton Templeton, its first black graduate and only the third black man to graduate from a college in the United States. In 1873, Margaret Boyd received her B.A. degree and became the first woman to graduate from the University. Soon after, the institution graduated its first international alumnus, Saki Taro Murayama of Japan, in 1895.

     
  • richardmitnick 8:00 am on March 31, 2016 Permalink | Reply
    Tags: , , , , Nanotechnology   

    From LBL: “Revealing the Fluctuations of Flexible DNA in 3-D” 

    Berkeley Logo

    Berkeley Lab

    March 30, 2016
    Glenn Roberts Jr.
    510-486-5582
    geroberts@lbl.gov

    `
    In a Berkeley Lab-led study, flexible double-helix DNA segments connected to gold nanoparticles are revealed from the 3-D density maps (purple and yellow) reconstructed from individual samples using a Berkeley Lab-developed technique called individual-particle electron tomography or IPET. Projections of the structures are shown in the background grid. (Credit: Berkeley Lab)

    An international team working at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has captured the first high-resolution 3-D images from individual double-helix DNA segments attached at either end to gold nanoparticles. The images detail the flexible structure of the DNA segments, which appear as nanoscale jump ropes.

    This unique imaging capability, pioneered by Berkeley Lab scientists, could aid in the use of DNA segments as building blocks for molecular devices that function as nanoscale drug-delivery systems, markers for biological research, and components for computer memory and electronic devices. It could also lead to images of important disease-relevant proteins that have proven elusive for other imaging techniques, and of the assembly process that forms DNA from separate, individual strands.

    The shapes of the coiled DNA strands, which were sandwiched between polygon-shaped gold nanoparticles, were reconstructed in 3-D using a cutting-edge electron microscope technique coupled with a protein-staining process and sophisticated software that provided structural details to the scale of about 2 nanometers, or two billionths of a meter.

    “We had no idea about what the double-strand DNA would look like between the nanogold particles,” said Gang “Gary” Ren, a Berkeley Lab scientist who led the research. “This is the first time for directly visualizing an individual double-strand DNA segment in 3-D,” he said. The results were published in the March 30 edition of Nature Communications.

    The method developed by this team, called individual-particle electron tomography (IPET), had earlier captured the 3-D structure of a single protein that plays a key role in human cholesterol metabolism. By grabbing 2-D images of the same object from different angles, the technique allows researchers to assemble a 3-D image of that object. The team has also used the technique to uncover the fluctuation of another well-known flexible protein, human immunoglobulin 1, which plays a role in our immune system.


    Access mp4 video here .

    For this latest study of DNA nanostructures, Ren used an electron-beam study technique called cryo-electron microscopy (cryo-EM) to examine frozen DNA-nanogold samples, and used IPET to reconstruct 3-D images from samples stained with heavy metal salts. The team also used molecular simulation tools to test the natural shape variations, called “conformations,” in the samples, and compared these simulated shapes with observations.

    Ren explained that the naturally flexible dynamics of samples, like a man waving his arms, cannot be fully detailed by any method that uses an average of many observations.

    A popular way to view the nanoscale structural details of delicate biological samples is to form them into crystals and zap them with X-rays, though this does not preserve their natural shape and the DNA-nanogold samples in this study are incredibly challenging to crystallize. Other common research techniques may require a collection of thousands near-identical objects, viewed with an electron microscope, to compile a single, averaged 3-D structure. But this 3-D image may not adequately show the natural shape fluctuations of a given object.

    The samples in the latest experiment were formed from individual polygon gold nanostructures, measuring about 5 nanometers across, connected to single DNA-segment strands with 84 base pairs. Base pairs are basic chemical building blocks that give DNA its structure. Each individual DNA segment and gold nanoparticle naturally zipped together with a partner to form the double-stranded DNA segment with a gold particle at either end.


    Access mp4 video here .
    These views compare the various shape fluctuations obtained from different samples of the same type of double-helix DNA segment (DNA renderings in green, 3-D reconstructions in purple) connected to gold nanoparticles (yellow). (Credit: Berkeley Lab)

    The samples were flash-frozen to preserve their structure for study with cryo-EM imaging, and the distance between the two gold particles in individual samples varied from 20-30 nanometers based on different shapes observed in the DNA segments. Researchers used a cryo-electron microscope at Berkeley Lab’s Molecular Foundry for this study.

    They collected a series of tilted images of the stained objects, and reconstructed 14 electron-density maps that detailed the structure of individual samples using the IPET technique. They gathered a dozen conformations for the samples and found the DNA shape variations were consistent with those measured in the flash-frozen cryo-EM samples. The shapes were also consistent with samples studied using other electron-based imaging and X-ray scattering methods, and with computer simulations.

    While the 3-D reconstructions show the basic nanoscale structure of the samples, Ren said that the next step will be to work to improve the resolution to the sub-nanometer scale.

    3
    Gang Ren (standing) and Lei Zhang participated in a study at Berkeley Lab’s Molecular Foundry that produced 3-D reproductions of individual samples of double-helix DNA segments attached to gold nanoparticles. (Photo by Roy Kaltschmidt/Berkeley Lab)

    “Even in this current state we begin to see 3-D structures at 1- to 2-nanometer resolution,” he said. “Through better instrumentation and improved computational algorithms, it would be promising to push the resolution to that visualizing a single DNA helix within an individual protein.”

    The technique, he said, has already excited interest among some prominent pharmaceutical companies and nanotechnology researchers, and his science team already has dozens of related research projects in the pipeline.

    In future studies, researchers could attempt to improve the imaging resolution for complex structures that incorporate more DNA segments as a sort of “DNA origami,” Ren said. Researchers hope to build and better characterize nanoscale molecular devices using DNA segments that can, for example, store and deliver drugs to targeted areas in the body.

    “DNA is easy to program, synthesize and replicate, so it can be used as a special material to quickly self-assemble into nanostructures and to guide the operation of molecular-scale devices,” he said. “Our current study is just a proof of concept for imaging these kinds of molecular devices’ structures.”

    The Molecular Foundry is a DOE Office of Science User Facility.

    In addition to Berkeley Lab scientists, other researchers contributing to this study were from UC Berkeley, the Kavli Energy NanoSciences Institute at Berkeley Lab and UC Berkeley, and Xi’an Jiaotong University in China.

    This work was supported by the National Science Foundation, DOE Office of Basic Energy Sciences, National Institutes of Health, the National Natural Science Foundation of China, Xi’an Jiaotong University in China, and the Ministry of Science and Technology in China.

    View more about Gary Ren’s research group here.

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  • richardmitnick 4:50 pm on March 28, 2016 Permalink | Reply
    Tags: , , Nanotechnology,   

    From phys.org: “New nanoparticle reveals cancer treatment effectiveness in real time” 

    physdotorg
    phys.org

    March 28, 2016

    1
    Using reporter nanoparticles loaded with either a chemotherapy or immunotherapy, researchers could distinguish between drug-sensitive and drug-resistant tumors in a pre-clinical model of prostate cancer. Credit: Ashish Kulkarni, Brigham and Women’s Hospital

    Being able to detect early on whether a cancer therapy is working for a patient can influence the course of treatment and improve outcomes and quality of life. However, conventional detection methods—such as PET scans, CT and MRI—usually cannot detect whether a tumor is shrinking until a patient has received multiple cycles of therapy.

    A new technique developed in pre-clinical models by investigators at Brigham and Women’s Hospital (BWH) offers a new approach and a read out on the effectiveness of chemotherapy in as few as eight hours after treatment. The technology can also be used for monitoring the effectiveness of immunotherapy. Using a nanoparticle that delivers a drug and then fluoresces green when cancer cells begin dying, researchers were able to visualize whether a tumor is resistant or susceptible to a particular treatment much sooner than currently available clinical methods.

    The team’s findings are published online this week in The Proceedings of the National Academy of Sciences.

    “Using this approach, the cells light up the moment a cancer drug starts working. We can determine if a cancer therapy is effective within hours of treatment,” said co-corresponding author Shiladitya Sengupta, PhD, a principal investigator in BWH’s Division of Bioengineering. “Our long-term goal is to find a way to monitor outcomes very early so that we don’t give a chemotherapy drug to patients who are not responding to it.”

    The new technique takes advantage of the fact that when cells die, a particular enzyme known as caspase is activated. The researchers designed a ‘reporter element’ that, when in the presence of activated caspase, glows green. The team then tested whether they could use the reporter nanoparticles to distinguish between drug-sensitive and drug-resistant tumors. Using nanoparticles loaded with anti-cancer drugs, the team tested a common chemotherapeutic agent, paclitaxel, in a pre-clinical model of prostate cancer and, separately, an immunotherapy that targets PD-L 1 in a pre-clinical model of melanoma. In the tumors that were sensitive to paclitaxel, the team saw an approximately 400 percent increase in fluorescence compared to tumors that were not sensitive to the drug. The team also saw a significant increase in the fluorescent signal in tumors treated with the anti-PD-L1 nanoparticles after five days.

    “We’ve demonstrated that this technique can help us directly visualize and measure the responsiveness of tumors to both types of drugs,” said co-corresponding author Ashish Kulkarni, an instructor in the Division of Biomedical Engineering at BWH. “Current techniques, which rely on measurements of the size or metabolic state of the tumor, are sometimes unable to detect the effectiveness of an immunotherapeutic agent as the volume of the tumor may actually increase as immune cells begin to flood in to attack the tumor. Reporter nanoparticles, however, can give us an accurate read out of whether or not cancer cells are dying.”

    Researchers now plan to focus on the design of radiotracers that can be used in humans, and tests of both safety and efficacy will be necessary before the current technique can be translated into clinical applications. Sengupta, Kulkarni and their colleagues are actively working on these steps in order to further the lab’s goal of improving the management and treatment of cancer using nanotechnology.

    More information: Reporter nanoparticle that monitors its anticancer efficacy in real time, PNAS, http://www.pnas.org/cgi/doi/10.1073/pnas.1603455113

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    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 11:22 am on March 22, 2016 Permalink | Reply
    Tags: , , Nanotechnology   

    From MIT: “Nanocrystal self-assembly sheds its secrets” 

    MIT News
    MIT News

    1
    At left, randomly oriented nanocrystals are illustrated as they would appear in solution. At right, two layers of the atomically aligned nanocrystal superlattice are illustrated on the substrate. Images courtesy of the Tisdale Lab.

    A new approach gives a real-time look at how the complex structures form.

    March 21, 2016
    Michael Patrick Rutter | School of Engineering

    The secret to a long-hidden magic trick behind the self-assembly of nanocrystal structures is starting to be revealed.

    The transformation of simple colloidal particles — bits of matter suspended in solution — into tightly packed, beautiful lace-like meshes, or superlattices, has puzzled researchers for decades. Pretty pictures in themselves, these tiny superlattices, also called quantum dots, are being used to create more vivid display screens as well as arrays of optical sensory devices. The ultimate potential of quantum dots to make any surface into a smart screen or energy source hinges, in part, on understanding how they form.

    Through a combination of techniques including controlled solvent evaporation and synchrotron X-ray scattering, the real time self-assembly of nanocrystal structures has now become observable in-situ. The findings were reported in the journal Nature Materials in a paper by Assistant Professor William A. Tisdale and grad student Mark C. Weidman, both at MIT’s Department of Chemical Engineering, and Detlef-M. Smilgies at the Cornell High Energy Synchrotron Source (CHESS).

    The researchers anticipate their new findings will have implications for the direct manipulation of resulting superlattices, with the possibility of on-demand fabrication and the potential to generate principles for the formation of related soft materials such as proteins and polymers.

    Quantum dot disco

    Tisdale and his colleagues are among the many groups who study hard semiconductor nanocrystals with surfaces coated with organic molecules. These solution-processable electronic materials are on store shelves now under a variety of names, incorporated into everything from lighting displays to TVs. They also are being eyed for making efficient solar cells and other energy conversion devices due to their ease of fabrication and low-cost manufacturing processes.

    The broader adoption of these nanocrystals into other energy conversion technologies has been limited, in part, by the lack of knowledge about how they self-assemble, going from colloidal particles (like tiny Styrofoam balls suspended in a liquid) to superlattices (picture those same balls now dry, packed, and aligned).

    Techniques including electron microscopy and dynamic light scattering have uncovered some aspects of the starting colloidal state and the final superlattice structure, but they have not illuminated the transition between these two states. In fact, such foundational work dates back to the mid-1990s with Moungi Bawendi’s group at MIT.

    “In the past 10 to 15 years, a lot of progress has been made in making very beautiful nanocrystal structures,” Tisdale says. “However, there’s still a lot of debate about why they assemble into each configuration. Is it ligand entropy or the faceting of the nanocrystals? The depth of information provided by watching the entire self-organization process unfold in real time can help answer these questions.”

    “We believe this was the first experiment that has allowed us to watch in real time and in a native environment how self-assembly occurs,” Tisdale says. “These experiments would not have been possible without the experimental capabilities developed by Detlef and the CHESS team.”

    The use of nanocrystals with a heavy element (lead) and the brightness of the synchrotron X-ray source enabled sufficiently fast data collection that self-assembly could be observed in real time, resulting in compelling images and movies of the process.

    A fine mesh

    The discovery may lead to refined models for self-assembly of a wide range of organic soft materials. Moreover, the ability to watch the structure as it is evolving in real time also holds promise for intervening or directing the system into desired configurations, presaging a future how-to guide for creating superlattices.

    Tisdale says that much more work needs to be done to gain insights about why nanocrystals self-assemble they way they do. He and his team plan to use their new technique to manipulate parameters such as solvent conditions as well as the size and shape of nanocrystals, and to more closely study the ligands on the surface as they seem to be the key driver for self-assembly.

    “We hope that this study and technique will help to increase our understanding of colloidal self-assembly and, in the long term, enable us to direct nanoscale self-assembly toward a desired structure,” Weidman adds.

    The work was supported as part of the Center for Excitonics, an Energy Frontier Research Center funded by the U.S. Department of Energy Office of Basic Energy Sciences. The Cornell High Energy Synchrotron Source (CHESS) is supported by the National Science Foundation and the National Institutes of Health/National Institute of General Medical Sciences.

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  • richardmitnick 7:20 am on March 21, 2016 Permalink | Reply
    Tags: , Nanotechnology, , Stanford scientists develop new technique for imaging cells and tissues under the skin   

    From Stanford: “Stanford scientists develop new technique for imaging cells and tissues under the skin” 

    Stanford University Name
    Stanford University

    March 18, 2016
    Amy Adams

    1

    Scientists have many tools at their disposal for looking at preserved tissue under a microscope in incredible detail, or peering into the living body at lower resolution. What they haven’t had is a way to do both: create a three-dimensional real-time image of individual cells or even molecules in a living animal.

    Now, Stanford scientists have provided the first glimpse under the skin of a living animal, showing intricate real-time details in three dimensions of the lymph and blood vessels.

    The technique, called MOZART (for MOlecular imaging and characteriZation of tissue noninvasively At cellular ResoluTion), could one day allow scientists to detect tumors in the skin, colon or esophagus, or even to see the abnormal blood vessels that appear in the earliest stages of macular degeneration – a leading cause of blindness.

    “We’ve been trying to look into the living body and see information at the level of the single cell,” said Adam de la Zerda, an assistant professor of structural biology at Stanford and senior author on the paper. “Until now there has been no way do that.”

    De la Zerda, who is also a member of Stanford Bio-X, said the technique could allow doctors to monitor how an otherwise invisible tumor under the skin is responding to treatment, or to understand how individual cells break free from a tumor and travel to distant sites.

    Going for gold

    A technique exists for peeking into a live tissue several millimeters under the skin, revealing a landscape of cells, tissues and vessels. But that technique, called optical coherence tomography, or OCT, isn’t sensitive or specific enough to see the individual cells or the molecules that the cells are producing, which is what interests de la Zerda.

    A major issue has been finding a way of differentiating between cells or tissues; for example, picking out the cancerous cells beginning to multiply within an overall healthy tissue. In other forms of microscopy, scientists have created tags that latch onto molecules or structures of interest to illuminate those structures and provide a detailed view of where they are in the cell or body.

    No such beacons existed for OCT, though de la Zerda knew that tiny particles called gold nanorods had some of the properties he was looking for. The problem was that the commercially available nanorods didn’t produce nearly enough signal to be detected in a tissue.

    What the team needed were nanorods, but big ones. Nanorods are analogous to organ pipes, said graduate student Elliott SoRelle, because longer pipes vibrate at lower frequencies, creating a deep, low sound. Likewise, longer nanorods vibrate at lower frequencies, or wavelengths, of light. Those vibrations scatter the light, which the microscope detects.

    If all the other tissues are vibrating in a white noise of higher frequencies, longer nanorods would stand out like low organ notes amidst a room of babble.

    SoRelle’s challenge was to manufacture longer nanorods that were nontoxic, stable and very bright, which turned out to be a lot to ask. “My background was biochemistry, and this turned out to be a problem of materials science and surface chemistry,” said SoRelle, who was co-first author on the paper. He can now make nontoxic nanorods in various sizes that all vibrate at unique and identifiable frequencies.

    Eliminating noise

    The next challenge was filtering out the nanorods’ frequency from the surrounding tissue.

    To do that, electrical engineering graduate student and Bowes Bio-X Fellow Orly Liba developed computer algorithms that could separate out the frequencies of light scattered by nanorods of various lengths and differentiate those from surrounding tissue.

    With SoRelle’s large nanorods and Liba’s sensitive algorithms, de la Zerda and his team had solved the initial problem of detecting specific structures in three-dimensional images of living tissues. The resulting three-dimensional, high-resolution images were so big – on the order of gigapixels – that the team needed to develop additional algorithms for analyzing and storing such large images.

    The team tested their technology in the ear of a living mouse, where they were able to watch as the nanorods were taken up into the lymph system and transported through a network of valves. They were able to distinguish between two different size nanorods that resonated at different wavelengths in separate lymph vessels, and they could distinguish between those two nanorods in the lymph system and the blood vessels. In one study, they could watch individual valves within the lymph vessels open and close to control the flow of fluid in a single direction.

    “Nobody has shown that level of detail before,” said Liba, who was co-first author on the paper.

    Impossible goal

    This detailed imaging was de la Zerda’s initial goal when he started his lab in 2012, though he was frequently told it would be impossible. “I’m in a small department, but with very accomplished faculty,” he said. “One faculty member told me his own life story of taking big risks and that encouraged me. I thought it would be really fun to see if we can make it work and see cells talking to each other in real time.”

    His gamble got off the ground primarily with a seed grant from Stanford Bio-X, which supports early-stage interdisciplinary research. “That grant allowed us to take a big risk in a direction that was completely unproven,” de la Zerda said.

    Having shown that the gold nanorods can be seen in living tissue, the next step is to show that those nanorods can bind to specific kinds of cells, like skin cancer or abnormal vessels in early stage macular degeneration. Then, the technique could be used to learn more about how those diseases progress at the molecular level and also evaluate treatments in individual patients, something that previously hadn’t been possible.

    The work was funded by the U.S. Air Force, the National Institutes of Health Directors Office, the National Science Foundation, the Damon Runyon Cancer Research Foundation, the Susan G. Komen Breast Cancer Foundation, the Mary Kay Foundation, the Donald E. and Delia B. Baxter Foundation, the Center for Cancer Nanotechnology Excellence and Translation, the Arnold and Mabel Beckman Initiative for Macular Research, the Pew Charitable Trusts and the Alexander and Margaret Stewart Trust, the Skippy Frank Foundation, the Claire Giannini Fund and Stanford Bio-X.

    See the full article here .

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    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

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  • richardmitnick 5:59 pm on February 5, 2016 Permalink | Reply
    Tags: , , , Nanotechnology   

    From BNL: “Scientists Guide Gold Nanoparticles to Form “Diamond” Superlattices” 

    Brookhaven Lab

    February 4, 2016
    Karen McNulty Walsh, (631) 344-8350
    Peter Genzer, (631) 344-3174

    DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond.

    Using bundled strands of DNA to build Tinkertoy-like tetrahedral cages, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have devised a way to trap and arrange nanoparticles in a way that mimics the crystalline structure of diamond. The achievement of this complex yet elegant arrangement, as described in a paper published February 5, 2016, in Science, may open a path to new materials that take advantage of the optical and mechanical properties of this crystalline structure for applications such as optical transistors, color-changing materials, and lightweight yet tough materials.

    “We solved a 25-year challenge in building diamond lattices in a rational way via self-assembly,” said Oleg Gang, a physicist who led this research at the Center for Functional Nanomaterials (CFN) at Brookhaven Lab in collaboration with scientists from Stony Brook University, Wesleyan University, and Nagoya University in Japan.

    The scientists employed a technique developed by Gang that uses fabricated DNA as a building material to organize nanoparticles into 3D spatial arrangements. They used ropelike bundles of double-helix DNA to create rigid, three-dimensional frames, and added dangling bits of single-stranded DNA to bind particles coated with complementary DNA strands.

    “We’re using precisely shaped DNA constructs made as a scaffold and single-stranded DNA tethers as a programmable glue that matches up particles according to the pairing mechanism of the genetic code—A binds with T, G binds with C,” said Wenyan Liu of the CFN, the lead author on the paper. “These molecular constructs are building blocks for creating crystalline lattices made of nanoparticles.”
    The difficulty of diamond

    As Liu explained, “Building diamond superlattices from nano- and micro-scale particles by means of self-assembly has proven remarkably difficult. It challenges our ability to manipulate matter on small scales.”

    The reasons for this difficulty include structural features such as a low packing fraction—meaning that in a diamond lattice, in contrast to many other crystalline structures, particles occupy only a small part of the lattice volume—and strong sensitivity to the way bonds between particles are oriented. “Everything must fit together in just such a way without any shift or rotation of the particles’ positions,” Gang said. “Since the diamond structure is very open, many things can go wrong, leading to disorder.”

    “Even to build such structures one-by-one would be challenging,” Liu added, “and we needed to do so by self-assembly because there is no way to manipulate billions of nanoparticles one–by–one.”

    Gang’s previous success using DNA to construct a wide range of nanoparticle arrays suggested that a DNA-based approach might work in this instance.

    DNA guides assembly

    The team first used the ropelike DNA bundles to build tetrahedral “cages”—a 3D object with four triangular faces. They added single-stranded DNA tethers pointing toward the interior of the cages using T,G,C,A sequences that matched up with complementary tethers attached to gold nanoparticles. When mixed in solution, the complementary tethers paired up to “trap” one gold nanoparticle inside each tetrahedron cage.

    Double stranded DNA bundles (gray) form tetrahedral cages
    Schematic illustration of the experimental strategy: Double stranded DNA bundles (gray) form tetrahedral cages. Single stranded DNA strands on the edges (green) and vertices (red) match up with complementary strands on gold nanoparticles. This results in a single gold particle being trapped inside each tetrahedral cage, and the cages binding together by tethered gold nanoparticles at each vertex. The result is a crystalline nanoparticle lattice that mimics the long-range order of crystalline diamond. The images below the schematic are (left to right): a reconstructed cryo-EM density map of the tetrahedron, a caged particle shown in a negative-staining TEM image, and a diamond superlattice shown at high magnification with cryo-STEM.

    The arrangement of gold nanoparticles outside the cages was guided by a different set of DNA tethers attached at the vertices of the tetrahedrons. Each set of vertices bound with complementary DNA tethers attached to a second set of gold nanoparticles.

    When mixed and annealed, the tetrahedral arrays formed superlattices with long-range order where the positions of the gold nanoparticles mimics the arrangement of carbon atoms in a lattice of diamond, but at a scale about 100 times larger.

    “Although this assembly scenario might seem hopelessly unconstrained, we demonstrate experimentally that our approach leads to the desired diamond lattice, drastically streamlining the assembly of such a complex structure,” Gang said.

    The proof is in the images. The scientists used cryogenic transmission electron microscopy (cryo-TEM) to verify the formation of tetrahedral frames by reconstructing their 3D shape from multiple images. Then they used in-situ small-angle x-ray scattering (SAXS) at the National Synchrotron Light Source (NSLS), and cryo scanning transmission electron microscopy (cryo-STEM) at the CFN, to image the arrays of nanoparticles in the fully constructed lattice.

    “Our approach relies on the self-organization of the triangularly shaped blunt vertices of the tetrahedra (so called ‘footprints’) on isotropic spherical particles. Those triangular footprints bind to spherical particles coated with complementary DNA, which allows the particles to coordinate their arrangement in space relative to one another. However, the footprints can arrange themselves in a variety of patterns on a sphere. It turns that one particular placement is more favorable, and it corresponds to the unique 3D placement of particles that locks the diamond lattice,” Gang said.

    The team supported their interpretation of the experimental results using theoretical modeling that provided insight about the main factors driving the successful formation of diamond lattices.

    Sparkling implications

    “This work brings to the nanoscale the crystallographic complexity seen in atomic systems,” said Gang, who noted that the method can readily be expanded to organize particles of different material compositions. The group has demonstrated previously that DNA-assembly methods can be applied to optical, magnetic, and catalytic nanoparticles as well, and will likely yield the long-sought novel optical and mechanical materials scientists have envisioned.

    “We’ve demonstrated a new paradigm for creating complex 3D-ordered structures via self-assembly. If you can build this challenging lattice, the thinking is you can build potentially a variety of desired lattices,” he said.

    This work was funded by the DOE Office of Science (BES). CFN and NSLS are DOE Office of Science User Facilities.

    See the full article here .

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    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 2:17 pm on February 2, 2016 Permalink | Reply
    Tags: , DESY Nanolab, Nanotechnology   

    From DESY: “Scientists synthesise new class of material of a new class” 

    DESY
    DESY

    2016/02/01
    No writer credit found

    Applications in medical technology and manufacturing

    Classical materials such as ceramics, metals and polymers have their typical mechanical properties. They are hard, soft, strong, flexible or stiff. Hamburg research scientists have now synthesized a material that unites several different properties, and could thereby open the way to new applications in medical engineering and manufacturing. The scientists from the Hamburg University of Technology (TUHH), the University of Hamburg, the Helmholtz Centre Geesthacht and DESY have presented their novel nanocomposite in the journal Nature Materials. This new class of material could for example be suitable for filling dental cavities, or manufacturing watch cases. The materials used in applications like these need to be both hard and damage-tolerant.

    DESY Nanolab I
    DESY Nanolab II
    DESY Nanolab

    The research scientists have developed a new technique which produces a material that is at the same time strong, hard and stiff. To achieve this, the scientists first employed a standard procedure, widely used when working with nanoparticles, whereby ceramic iron oxide nanoparticles are deposited in a regular array. This is done with the help of organic oleic acid, which seeps into the narrow gaps between the nanoparticles and holds them together.

    “The self-organisation of these nanoparticles leads to an extended, closely packed supercrystal reminiscent of atomic crystal lattices,” explains one of the authors, Axel Dreyer from the TUHH. The crucial discovery is that by subsequently exposing the material to moderate heat levels, the resulting nanocomposite displays a much stronger cohesion and its mechanical properties are unlike those of any other.

    On the smallest scale, the structure of the new material resembles that of biological hard tissues, such as mother of pearl and dental enamel. It consists of uniformly sized iron oxide nanoparticles, which are coated with oleic acid. In previous studies, the bonds between the oleic acid molecules were very weak and due to so-called Van der Waals’ forces. By drying and pressing the material at an elevated temperature and then applying a controlled thermal treatment, the scientist have now managed to create a much stronger bond between the oleic acid molecules, thereby markedly improving the mechanical properties of the nanocomposite.

    Since oleic acid is very often used when processing other nanoparticles too, this new method could potentially improve the mechanical properties of a great many other nanocomposites as well. The bonding properties of the oleic acid, which serves as an adhesive, have been examined spectroscopically by the staff of the DESY-Nanolab. “Our measurements showed that the oleic acid molecules survive the thermal treatment and form additional crosslinks during the process,” reports co-author Andreas Stierle, a Leading Scientist at DESY. “This important finding can serve as the basis for successfully modelling the mechanical properties of this novel material.”

    Reference:
    “Organically linked iron oxide nanoparticle supercrystals with exceptional isotropic mechanical properties“; Axel Dreyer, Artur Feld, Andreas Kornowski, Ezgi D. Yilmaz, Heshmat Noei, Andreas Meyer, Tobias Krekeler, Chengge Jiao, Andreas Stierle, Volker Abetz, Horst Weller and Gerold A. Schneider; „Nature Materials“, 2016; DOI: 10.1038/NMAT4553

    See the full article here .

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    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

     
  • richardmitnick 5:56 pm on November 12, 2015 Permalink | Reply
    Tags: , , Nanotechnology   

    From Cornell: “Cornell nanomaterials lab opens doors to public” 

    Cornell Bloc

    Cornell University

    1
    A nanomaterials lab at Kimball Hall.

    Nov. 2, 2015
    Syl Kacapyr

    A nanomaterials research laboratory in Cornell’s Kimball Hall is opening its doors to the public for the first time. It is expected to draw interest from students, researchers and companies looking to gain access to its state-of-the-art equipment and to spark innovations in energy, medicine and technology.

    The opportunity comes with the expiration of a grant from the King Abdullah University of Science and Technology (KAUST), which established the KAUST-Cornell Center for Energy and Sustainability in 2008. The partnership has ended, but the equipment and interest in nanomaterials research remain.

    The College of Engineering is leading the open-door effort and is rebranding the 4,000-square-foot lab as the Center for Nanomaterials Engineering and Technology (CNET). For a fee, anyone from undergraduates to industry giants can access the lab and take a new material from concept to prototype.

    The lab – which includes equipment for materials synthesis, physical characterization and scale-up – can be used to develop and analyze materials for applications including carbon capture and conversion, electrochemical energy storage in batteries, and hydrogels for biomedicine and drug delivery.

    Lynden Archer, CNET co-director and director of the School of Chemical and Biomolecular Engineering, says the infrastructure in the facility already has demonstrated its ability to take products from concept to early stage commercialization.

    “For the last seven years my group has pursued research on design, synthesis and analysis of a family of nanoparticle-hybrid polymer materials that emerged as important candidates as electrolytes in batteries,” Archer said. Termed NOHMs, Nanoscale Organic Hybrid Materials, the materials improve battery safety and performance by both physical and chemical pathways. The concept was spun out to create a technology startup company called NOHMs Technologies that initially was located in Cornell’s Langmuir Labs. Ultimately the NOHMs team outgrew their space in Langmuir and moved to Rochester’s Eastman Business Park to pursue the next phase of its development.

    The open lab also can encourage new partnerships between companies and the university. Such a partnership blossomed when Summit Lubricants, a company from Batavia, New York, was attracted to the lab to research novel nanoparticle-based lubricant materials. “These lubricants took advantage of the hardness of inorganic nanoparticles and the softness of an associated polymer to create materials with more flexible property profiles, in kilogram-scale quantities. It is remarkable that we were able to take these materials all the way from concept through physical property screening to scale-up in one facility,” Archer said.

    CNET will provide the same entrepreneurial opportunity to students by establishing a business incubator in the facility as part of a new entrepreneurship program designed to enhance the experiential learning opportunities of engineering doctoral students. “It will offer an opportunity for Cornell Ph.D. students to develop technologies to a level that goes beyond the limitations of academic research and prepares them for entrepreneurship when they graduate,” said Bruce van Dover, CNET co-director and chair of the Department of Materials Science and Engineering.

    Aside from local users, the open lab is expected to draw national interest from major companies from the energy, food, medical and electronics industries as part of a new industry-university institute under development in CNET. About 20 companies will be invited to participate in the partnership under the Institute for Fundamental Research in Separations Science.

    Mark Hurwitz, institute director and adjunct professor of chemical and biomolecular engineering, says companies will participate in research, study groups and seminars and have early access to results. “The filtration and separations industry lacks the firm theoretical underpinning and useful mathematical models one finds in other industries. The specific areas I have in mind are filtration, both direct flow and cross flow, chromatography and coalescence,” said Hurwitz, who described separation processes as “incredibly complicated,” adding that knowledge gained through the institute will substantially reduce the need to rely on expensive and time-consuming experimentation for product development.

    While CNET will generate revenue for the university, Archer and van Dover say that isn’t the goal of opening the lab to the public. They say, more importantly, the opportunity will help facilitate technology transfer from the university to industry. It also will enable development of new models to educate graduate students interested in translating research into products that affect everyday lives.

    CNET has been open since the beginning of October. Visit CNET’s website for more information.

    See the full article here .

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    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
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