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  • richardmitnick 3:31 pm on January 28, 2013 Permalink | Reply
    Tags: , , Electron Microscopy,   

    From PNNL Lab: “Seeing a Common Catalyst with New Eyes” 

    Chemical imaging microscope shows corrugated gamma-alumina surface
    January 2013
    Suraiya Farukhi
    Christine Sharp

    Results: Neither smooth nor disordered, gamma-alumina nanoparticles are corrugated with tiny pores inside, according to scientists at Pacific Northwest National Laboratory. Using a powerful transmission electron microscope, the team obtained ultrahigh-resolution images and chemical data about the particle’s surface. They found that the particles were covered with ridges made from a more open, yet symmetrical, arrangement of atoms. The open arrangement on the surfaces, notated as (110), covers 70% of the nanoparticle.

    pores
    The surface of the plate-like particles is far from smooth, according to a new transmission electron microscopy study conducted by Pacific Northwest National Laboratory and the FEI Company.

    By understanding the structure and function of tiny gamma-alumina particles, scientists are taking crucial steps to optimizing and realizing new useful properties for these materials. ‘If we can learn about the surfaces, then we can tailor them and make them more efficient in catalytic applications,’ said Dr. Libor Kovarik, who led the imaging study as part of PNNL’s Chemical Imaging Initiative.

    Why It Matters: Reducing refineries’ energy demands or car and truck emissions requires efficient catalysts on durable support materials. The supporting material must withstand severe temperature and pressure changes. Gamma-alumina has been studied extensively, but its atomic arrangement has not been established because of the challenge of getting a detailed view of this complex material. Accurately describing the atomic structure is crucial for understanding and taking advantage of the best properties of gamma-alumina.

    ‘Catalytic research demands this type of state-of-the-art chemical imaging research,’ said Dr. Charles Peden, a heterogeneous catalysis scientist who worked on the study, and an Associate Director of PNNL’s Institute for Integrated Catalysis. ‘Dr. Kovarik’s outstanding new images from this powerhouse microscope have yielded unprecedented new information about a catalyst material of enormous practical utility.'”

    See the full article here.

    Pacific Northwest National Laboratory (PNNL) is one of the United States Department of Energy National Laboratories, managed by the Department of Energy’s Office of Science. The main campus of the laboratory is in Richland, Washington.

    PNNL scientists conduct basic and applied research and development to strengthen U.S. scientific foundations for fundamental research and innovation; prevent and counter acts of terrorism through applied research in information analysis, cyber security, and the nonproliferation of weapons of mass destruction; increase the U.S. energy capacity and reduce dependence on imported oil; and reduce the effects of human activity on the environment. PNNL has been operated by Battelle Memorial Institute since 1965.

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  • richardmitnick 1:14 pm on January 17, 2013 Permalink | Reply
    Tags: , , Electron Microscopy,   

    From Berkeley Lab: “New Key to Organism Complexity Identified” 


    Berkeley Lab

    Berkeley Scientists Find that a Critical Transcription Factor Co-exists in Two Distinct States

    January 17, 2013
    Lynn Yarris

    The enormously diverse complexity seen amongst individual species within the animal kingdom evolved from a surprisingly small gene pool. For example, mice effectively serve as medical research models because humans and mice share 80-percent of the same protein-coding genes.

    image
    The ‘rearranged’ state of the lobe A (yellow) of the horseshoe-like TFIID transcription factor enables TFIID to bind with DNA (green) and start the process by which DNA is copied into RNA.

    The key to morphological and behavioral complexity, a growing body of scientific evidence suggests, is the regulation of gene expression by a family of DNA-binding proteins called ‘transcription factors.’ Now, a team of researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley has discovered the secret behind how one these critical transcription factors is able to perform – a split personality.

    Using a technique called single-particle cryo-electron microscopy, the team, which was led by biophysicist Eva Nogales, showed that the transcription factor known as ‘TFIID’ can co-exist in two distinct structural states.”

    two people
    Michael Cianfrocco and Eva Nogales used single-particle cryo-electron microscopy to learn how the TFIID transcription factor helps regulate of gene expression, a process critical to the growth, development, health and survival of all organisms. (Photo by Roy Kaltschmidt)

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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